diff options
Diffstat (limited to 'kernel/trace/ftrace.c')
| -rw-r--r-- | kernel/trace/ftrace.c | 7902 |
1 files changed, 5985 insertions, 1917 deletions
diff --git a/kernel/trace/ftrace.c b/kernel/trace/ftrace.c index 67708f46baae..3ec2033c0774 100644 --- a/kernel/trace/ftrace.c +++ b/kernel/trace/ftrace.c @@ -1,3 +1,4 @@ +// SPDX-License-Identifier: GPL-2.0 /* * Infrastructure for profiling code inserted by 'gcc -pg'. * @@ -15,10 +16,11 @@ #include <linux/stop_machine.h> #include <linux/clocksource.h> +#include <linux/sched/task.h> #include <linux/kallsyms.h> +#include <linux/security.h> #include <linux/seq_file.h> -#include <linux/suspend.h> -#include <linux/debugfs.h> +#include <linux/tracefs.h> #include <linux/hardirq.h> #include <linux/kthread.h> #include <linux/uaccess.h> @@ -32,14 +34,23 @@ #include <linux/list.h> #include <linux/hash.h> #include <linux/rcupdate.h> +#include <linux/kprobes.h> #include <trace/events/sched.h> +#include <asm/sections.h> #include <asm/setup.h> +#include "ftrace_internal.h" #include "trace_output.h" #include "trace_stat.h" +/* Flags that do not get reset */ +#define FTRACE_NOCLEAR_FLAGS (FTRACE_FL_DISABLED | FTRACE_FL_TOUCHED | \ + FTRACE_FL_MODIFIED) + +#define FTRACE_INVALID_FUNCTION "__ftrace_invalid_address__" + #define FTRACE_WARN_ON(cond) \ ({ \ int ___r = cond; \ @@ -57,41 +68,51 @@ }) /* hash bits for specific function selection */ -#define FTRACE_HASH_BITS 7 -#define FTRACE_FUNC_HASHSIZE (1 << FTRACE_HASH_BITS) #define FTRACE_HASH_DEFAULT_BITS 10 #define FTRACE_HASH_MAX_BITS 12 -#define FL_GLOBAL_CONTROL_MASK (FTRACE_OPS_FL_GLOBAL | FTRACE_OPS_FL_CONTROL) - #ifdef CONFIG_DYNAMIC_FTRACE -#define INIT_REGEX_LOCK(opsname) \ - .regex_lock = __MUTEX_INITIALIZER(opsname.regex_lock), +#define INIT_OPS_HASH(opsname) \ + .func_hash = &opsname.local_hash, \ + .local_hash.regex_lock = __MUTEX_INITIALIZER(opsname.local_hash.regex_lock), \ + .subop_list = LIST_HEAD_INIT(opsname.subop_list), #else -#define INIT_REGEX_LOCK(opsname) +#define INIT_OPS_HASH(opsname) #endif -static struct ftrace_ops ftrace_list_end __read_mostly = { +enum { + FTRACE_MODIFY_ENABLE_FL = (1 << 0), + FTRACE_MODIFY_MAY_SLEEP_FL = (1 << 1), +}; + +struct ftrace_ops ftrace_list_end __read_mostly = { .func = ftrace_stub, - .flags = FTRACE_OPS_FL_RECURSION_SAFE | FTRACE_OPS_FL_STUB, + .flags = FTRACE_OPS_FL_STUB, + INIT_OPS_HASH(ftrace_list_end) }; /* ftrace_enabled is a method to turn ftrace on or off */ int ftrace_enabled __read_mostly; -static int last_ftrace_enabled; - -/* Quick disabling of function tracer. */ -int function_trace_stop __read_mostly; +static int __maybe_unused last_ftrace_enabled; /* Current function tracing op */ struct ftrace_ops *function_trace_op __read_mostly = &ftrace_list_end; +/* What to set function_trace_op to */ +static struct ftrace_ops *set_function_trace_op; -/* List for set_ftrace_pid's pids. */ -LIST_HEAD(ftrace_pids); -struct ftrace_pid { - struct list_head list; - struct pid *pid; -}; +bool ftrace_pids_enabled(struct ftrace_ops *ops) +{ + struct trace_array *tr; + + if (!(ops->flags & FTRACE_OPS_FL_PID) || !ops->private) + return false; + + tr = ops->private; + + return tr->function_pids != NULL || tr->function_no_pids != NULL; +} + +static void ftrace_update_trampoline(struct ftrace_ops *ops); /* * ftrace_disabled is set when an anomaly is discovered. @@ -99,219 +120,175 @@ struct ftrace_pid { */ static int ftrace_disabled __read_mostly; -static DEFINE_MUTEX(ftrace_lock); +DEFINE_MUTEX(ftrace_lock); -static struct ftrace_ops *ftrace_global_list __read_mostly = &ftrace_list_end; -static struct ftrace_ops *ftrace_control_list __read_mostly = &ftrace_list_end; -static struct ftrace_ops *ftrace_ops_list __read_mostly = &ftrace_list_end; +struct ftrace_ops __rcu *ftrace_ops_list __read_mostly = (struct ftrace_ops __rcu *)&ftrace_list_end; ftrace_func_t ftrace_trace_function __read_mostly = ftrace_stub; -ftrace_func_t ftrace_pid_function __read_mostly = ftrace_stub; -static struct ftrace_ops global_ops; -static struct ftrace_ops control_ops; +struct ftrace_ops global_ops; -#if ARCH_SUPPORTS_FTRACE_OPS -static void ftrace_ops_list_func(unsigned long ip, unsigned long parent_ip, - struct ftrace_ops *op, struct pt_regs *regs); -#else -/* See comment below, where ftrace_ops_list_func is defined */ -static void ftrace_ops_no_ops(unsigned long ip, unsigned long parent_ip); -#define ftrace_ops_list_func ((ftrace_func_t)ftrace_ops_no_ops) -#endif +/* Defined by vmlinux.lds.h see the comment above arch_ftrace_ops_list_func for details */ +void ftrace_ops_list_func(unsigned long ip, unsigned long parent_ip, + struct ftrace_ops *op, struct ftrace_regs *fregs); +#ifdef CONFIG_DYNAMIC_FTRACE_WITH_CALL_OPS /* - * Traverse the ftrace_global_list, invoking all entries. The reason that we - * can use rcu_dereference_raw_notrace() is that elements removed from this list - * are simply leaked, so there is no need to interact with a grace-period - * mechanism. The rcu_dereference_raw_notrace() calls are needed to handle - * concurrent insertions into the ftrace_global_list. - * - * Silly Alpha and silly pointer-speculation compiler optimizations! + * Stub used to invoke the list ops without requiring a separate trampoline. */ -#define do_for_each_ftrace_op(op, list) \ - op = rcu_dereference_raw_notrace(list); \ - do +const struct ftrace_ops ftrace_list_ops = { + .func = ftrace_ops_list_func, + .flags = FTRACE_OPS_FL_STUB, +}; + +static void ftrace_ops_nop_func(unsigned long ip, unsigned long parent_ip, + struct ftrace_ops *op, + struct ftrace_regs *fregs) +{ + /* do nothing */ +} /* - * Optimized for just a single item in the list (as that is the normal case). + * Stub used when a call site is disabled. May be called transiently by threads + * which have made it into ftrace_caller but haven't yet recovered the ops at + * the point the call site is disabled. */ -#define while_for_each_ftrace_op(op) \ - while (likely(op = rcu_dereference_raw_notrace((op)->next)) && \ - unlikely((op) != &ftrace_list_end)) +const struct ftrace_ops ftrace_nop_ops = { + .func = ftrace_ops_nop_func, + .flags = FTRACE_OPS_FL_STUB, +}; +#endif static inline void ftrace_ops_init(struct ftrace_ops *ops) { #ifdef CONFIG_DYNAMIC_FTRACE if (!(ops->flags & FTRACE_OPS_FL_INITIALIZED)) { - mutex_init(&ops->regex_lock); + mutex_init(&ops->local_hash.regex_lock); + INIT_LIST_HEAD(&ops->subop_list); + ops->func_hash = &ops->local_hash; ops->flags |= FTRACE_OPS_FL_INITIALIZED; } #endif } -/** - * ftrace_nr_registered_ops - return number of ops registered - * - * Returns the number of ftrace_ops registered and tracing functions - */ -int ftrace_nr_registered_ops(void) -{ - struct ftrace_ops *ops; - int cnt = 0; - - mutex_lock(&ftrace_lock); - - for (ops = ftrace_ops_list; - ops != &ftrace_list_end; ops = ops->next) - cnt++; - - mutex_unlock(&ftrace_lock); - - return cnt; -} - -static void -ftrace_global_list_func(unsigned long ip, unsigned long parent_ip, - struct ftrace_ops *op, struct pt_regs *regs) -{ - int bit; - - bit = trace_test_and_set_recursion(TRACE_GLOBAL_START, TRACE_GLOBAL_MAX); - if (bit < 0) - return; - - do_for_each_ftrace_op(op, ftrace_global_list) { - op->func(ip, parent_ip, op, regs); - } while_for_each_ftrace_op(op); - - trace_clear_recursion(bit); -} - +/* Call this function for when a callback filters on set_ftrace_pid */ static void ftrace_pid_func(unsigned long ip, unsigned long parent_ip, - struct ftrace_ops *op, struct pt_regs *regs) -{ - if (!test_tsk_trace_trace(current)) - return; - - ftrace_pid_function(ip, parent_ip, op, regs); -} - -static void set_ftrace_pid_function(ftrace_func_t func) -{ - /* do not set ftrace_pid_function to itself! */ - if (func != ftrace_pid_func) - ftrace_pid_function = func; -} - -/** - * clear_ftrace_function - reset the ftrace function - * - * This NULLs the ftrace function and in essence stops - * tracing. There may be lag - */ -void clear_ftrace_function(void) -{ - ftrace_trace_function = ftrace_stub; - ftrace_pid_function = ftrace_stub; -} - -static void control_ops_disable_all(struct ftrace_ops *ops) -{ - int cpu; - - for_each_possible_cpu(cpu) - *per_cpu_ptr(ops->disabled, cpu) = 1; -} - -static int control_ops_alloc(struct ftrace_ops *ops) + struct ftrace_ops *op, struct ftrace_regs *fregs) { - int __percpu *disabled; + struct trace_array *tr = op->private; + int pid; - disabled = alloc_percpu(int); - if (!disabled) - return -ENOMEM; + if (tr) { + pid = this_cpu_read(tr->array_buffer.data->ftrace_ignore_pid); + if (pid == FTRACE_PID_IGNORE) + return; + if (pid != FTRACE_PID_TRACE && + pid != current->pid) + return; + } - ops->disabled = disabled; - control_ops_disable_all(ops); - return 0; + op->saved_func(ip, parent_ip, op, fregs); } -static void control_ops_free(struct ftrace_ops *ops) +void ftrace_sync_ipi(void *data) { - free_percpu(ops->disabled); + /* Probably not needed, but do it anyway */ + smp_rmb(); } -static void update_global_ops(void) +static ftrace_func_t ftrace_ops_get_list_func(struct ftrace_ops *ops) { - ftrace_func_t func; - /* - * If there's only one function registered, then call that - * function directly. Otherwise, we need to iterate over the - * registered callers. + * If this is a dynamic or RCU ops, or we force list func, + * then it needs to call the list anyway. */ - if (ftrace_global_list == &ftrace_list_end || - ftrace_global_list->next == &ftrace_list_end) { - func = ftrace_global_list->func; - /* - * As we are calling the function directly. - * If it does not have recursion protection, - * the function_trace_op needs to be updated - * accordingly. - */ - if (ftrace_global_list->flags & FTRACE_OPS_FL_RECURSION_SAFE) - global_ops.flags |= FTRACE_OPS_FL_RECURSION_SAFE; - else - global_ops.flags &= ~FTRACE_OPS_FL_RECURSION_SAFE; - } else { - func = ftrace_global_list_func; - /* The list has its own recursion protection. */ - global_ops.flags |= FTRACE_OPS_FL_RECURSION_SAFE; - } + if (ops->flags & (FTRACE_OPS_FL_DYNAMIC | FTRACE_OPS_FL_RCU) || + FTRACE_FORCE_LIST_FUNC) + return ftrace_ops_list_func; - - /* If we filter on pids, update to use the pid function */ - if (!list_empty(&ftrace_pids)) { - set_ftrace_pid_function(func); - func = ftrace_pid_func; - } - - global_ops.func = func; + return ftrace_ops_get_func(ops); } static void update_ftrace_function(void) { ftrace_func_t func; - update_global_ops(); + /* + * Prepare the ftrace_ops that the arch callback will use. + * If there's only one ftrace_ops registered, the ftrace_ops_list + * will point to the ops we want. + */ + set_function_trace_op = rcu_dereference_protected(ftrace_ops_list, + lockdep_is_held(&ftrace_lock)); + + /* If there's no ftrace_ops registered, just call the stub function */ + if (set_function_trace_op == &ftrace_list_end) { + func = ftrace_stub; /* * If we are at the end of the list and this ops is * recursion safe and not dynamic and the arch supports passing ops, * then have the mcount trampoline call the function directly. */ - if (ftrace_ops_list == &ftrace_list_end || - (ftrace_ops_list->next == &ftrace_list_end && - !(ftrace_ops_list->flags & FTRACE_OPS_FL_DYNAMIC) && - (ftrace_ops_list->flags & FTRACE_OPS_FL_RECURSION_SAFE) && - !FTRACE_FORCE_LIST_FUNC)) { - /* Set the ftrace_ops that the arch callback uses */ - if (ftrace_ops_list == &global_ops) - function_trace_op = ftrace_global_list; - else - function_trace_op = ftrace_ops_list; - func = ftrace_ops_list->func; + } else if (rcu_dereference_protected(ftrace_ops_list->next, + lockdep_is_held(&ftrace_lock)) == &ftrace_list_end) { + func = ftrace_ops_get_list_func(ftrace_ops_list); + } else { /* Just use the default ftrace_ops */ - function_trace_op = &ftrace_list_end; + set_function_trace_op = &ftrace_list_end; func = ftrace_ops_list_func; } + /* If there's no change, then do nothing more here */ + if (ftrace_trace_function == func) + return; + + /* + * If we are using the list function, it doesn't care + * about the function_trace_ops. + */ + if (func == ftrace_ops_list_func) { + ftrace_trace_function = func; + /* + * Don't even bother setting function_trace_ops, + * it would be racy to do so anyway. + */ + return; + } + +#ifndef CONFIG_DYNAMIC_FTRACE + /* + * For static tracing, we need to be a bit more careful. + * The function change takes affect immediately. Thus, + * we need to coordinate the setting of the function_trace_ops + * with the setting of the ftrace_trace_function. + * + * Set the function to the list ops, which will call the + * function we want, albeit indirectly, but it handles the + * ftrace_ops and doesn't depend on function_trace_op. + */ + ftrace_trace_function = ftrace_ops_list_func; + /* + * Make sure all CPUs see this. Yes this is slow, but static + * tracing is slow and nasty to have enabled. + */ + synchronize_rcu_tasks_rude(); + /* Now all cpus are using the list ops. */ + function_trace_op = set_function_trace_op; + /* Make sure the function_trace_op is visible on all CPUs */ + smp_wmb(); + /* Nasty way to force a rmb on all cpus */ + smp_call_function(ftrace_sync_ipi, NULL, 1); + /* OK, we are all set to update the ftrace_trace_function now! */ +#endif /* !CONFIG_DYNAMIC_FTRACE */ + ftrace_trace_function = func; } -static void add_ftrace_ops(struct ftrace_ops **list, struct ftrace_ops *ops) +static void add_ftrace_ops(struct ftrace_ops __rcu **list, + struct ftrace_ops *ops) { - ops->next = *list; + rcu_assign_pointer(ops->next, *list); + /* * We are entering ops into the list but another * CPU might be walking that list. We need to make sure @@ -321,7 +298,8 @@ static void add_ftrace_ops(struct ftrace_ops **list, struct ftrace_ops *ops) rcu_assign_pointer(*list, ops); } -static int remove_ftrace_ops(struct ftrace_ops **list, struct ftrace_ops *ops) +static int remove_ftrace_ops(struct ftrace_ops __rcu **list, + struct ftrace_ops *ops) { struct ftrace_ops **p; @@ -329,8 +307,11 @@ static int remove_ftrace_ops(struct ftrace_ops **list, struct ftrace_ops *ops) * If we are removing the last function, then simply point * to the ftrace_stub. */ - if (*list == ops && ops->next == &ftrace_list_end) { - *list = &ftrace_list_end; + if (rcu_dereference_protected(*list, + lockdep_is_held(&ftrace_lock)) == ops && + rcu_dereference_protected(ops->next, + lockdep_is_held(&ftrace_lock)) == &ftrace_list_end) { + rcu_assign_pointer(*list, &ftrace_list_end); return 0; } @@ -345,41 +326,16 @@ static int remove_ftrace_ops(struct ftrace_ops **list, struct ftrace_ops *ops) return 0; } -static void add_ftrace_list_ops(struct ftrace_ops **list, - struct ftrace_ops *main_ops, - struct ftrace_ops *ops) -{ - int first = *list == &ftrace_list_end; - add_ftrace_ops(list, ops); - if (first) - add_ftrace_ops(&ftrace_ops_list, main_ops); -} - -static int remove_ftrace_list_ops(struct ftrace_ops **list, - struct ftrace_ops *main_ops, - struct ftrace_ops *ops) -{ - int ret = remove_ftrace_ops(list, ops); - if (!ret && *list == &ftrace_list_end) - ret = remove_ftrace_ops(&ftrace_ops_list, main_ops); - return ret; -} +static void ftrace_update_trampoline(struct ftrace_ops *ops); -static int __register_ftrace_function(struct ftrace_ops *ops) +int __register_ftrace_function(struct ftrace_ops *ops) { - if (unlikely(ftrace_disabled)) - return -ENODEV; - - if (FTRACE_WARN_ON(ops == &global_ops)) + if (ops->flags & FTRACE_OPS_FL_DELETED) return -EINVAL; if (WARN_ON(ops->flags & FTRACE_OPS_FL_ENABLED)) return -EBUSY; - /* We don't support both control and global flags set. */ - if ((ops->flags & FL_GLOBAL_CONTROL_MASK) == FL_GLOBAL_CONTROL_MASK) - return -EINVAL; - #ifndef CONFIG_DYNAMIC_FTRACE_WITH_REGS /* * If the ftrace_ops specifies SAVE_REGS, then it only can be used @@ -393,19 +349,21 @@ static int __register_ftrace_function(struct ftrace_ops *ops) if (ops->flags & FTRACE_OPS_FL_SAVE_REGS_IF_SUPPORTED) ops->flags |= FTRACE_OPS_FL_SAVE_REGS; #endif + if (!ftrace_enabled && (ops->flags & FTRACE_OPS_FL_PERMANENT)) + return -EBUSY; - if (!core_kernel_data((unsigned long)ops)) + if (!is_kernel_core_data((unsigned long)ops)) ops->flags |= FTRACE_OPS_FL_DYNAMIC; - if (ops->flags & FTRACE_OPS_FL_GLOBAL) { - add_ftrace_list_ops(&ftrace_global_list, &global_ops, ops); - ops->flags |= FTRACE_OPS_FL_ENABLED; - } else if (ops->flags & FTRACE_OPS_FL_CONTROL) { - if (control_ops_alloc(ops)) - return -ENOMEM; - add_ftrace_list_ops(&ftrace_control_list, &control_ops, ops); - } else - add_ftrace_ops(&ftrace_ops_list, ops); + add_ftrace_ops(&ftrace_ops_list, ops); + + /* Always save the function, and reset at unregistering */ + ops->saved_func = ops->func; + + if (ftrace_pids_enabled(ops)) + ops->func = ftrace_pid_func; + + ftrace_update_trampoline(ops); if (ftrace_enabled) update_ftrace_function(); @@ -413,54 +371,14 @@ static int __register_ftrace_function(struct ftrace_ops *ops) return 0; } -static void ftrace_sync(struct work_struct *work) -{ - /* - * This function is just a stub to implement a hard force - * of synchronize_sched(). This requires synchronizing - * tasks even in userspace and idle. - * - * Yes, function tracing is rude. - */ -} - -static int __unregister_ftrace_function(struct ftrace_ops *ops) +int __unregister_ftrace_function(struct ftrace_ops *ops) { int ret; - if (ftrace_disabled) - return -ENODEV; - if (WARN_ON(!(ops->flags & FTRACE_OPS_FL_ENABLED))) return -EBUSY; - if (FTRACE_WARN_ON(ops == &global_ops)) - return -EINVAL; - - if (ops->flags & FTRACE_OPS_FL_GLOBAL) { - ret = remove_ftrace_list_ops(&ftrace_global_list, - &global_ops, ops); - if (!ret) - ops->flags &= ~FTRACE_OPS_FL_ENABLED; - } else if (ops->flags & FTRACE_OPS_FL_CONTROL) { - ret = remove_ftrace_list_ops(&ftrace_control_list, - &control_ops, ops); - if (!ret) { - /* - * The ftrace_ops is now removed from the list, - * so there'll be no new users. We must ensure - * all current users are done before we free - * the control data. - * Note synchronize_sched() is not enough, as we - * use preempt_disable() to do RCU, but the function - * tracer can be called where RCU is not active - * (before user_exit()). - */ - schedule_on_each_cpu(ftrace_sync); - control_ops_free(ops); - } - } else - ret = remove_ftrace_ops(&ftrace_ops_list, ops); + ret = remove_ftrace_ops(&ftrace_ops_list, ops); if (ret < 0) return ret; @@ -468,26 +386,29 @@ static int __unregister_ftrace_function(struct ftrace_ops *ops) if (ftrace_enabled) update_ftrace_function(); - /* - * Dynamic ops may be freed, we must make sure that all - * callers are done before leaving this function. - * - * Again, normal synchronize_sched() is not good enough. - * We need to do a hard force of sched synchronization. - */ - if (ops->flags & FTRACE_OPS_FL_DYNAMIC) - schedule_on_each_cpu(ftrace_sync); - + ops->func = ops->saved_func; return 0; } static void ftrace_update_pid_func(void) { + struct ftrace_ops *op; + /* Only do something if we are tracing something */ if (ftrace_trace_function == ftrace_stub) return; + do_for_each_ftrace_op(op, ftrace_ops_list) { + if (op->flags & FTRACE_OPS_FL_PID) { + op->func = ftrace_pids_enabled(op) ? + ftrace_pid_func : op->saved_func; + ftrace_update_trampoline(op); + } + } while_for_each_ftrace_op(op); + + fgraph_update_pid_func(); + update_ftrace_function(); } @@ -569,10 +490,10 @@ static void *function_stat_start(struct tracer_stat *trace) #ifdef CONFIG_FUNCTION_GRAPH_TRACER /* function graph compares on total time */ -static int function_stat_cmp(void *p1, void *p2) +static int function_stat_cmp(const void *p1, const void *p2) { - struct ftrace_profile *a = p1; - struct ftrace_profile *b = p2; + const struct ftrace_profile *a = p1; + const struct ftrace_profile *b = p2; if (a->time < b->time) return -1; @@ -583,10 +504,10 @@ static int function_stat_cmp(void *p1, void *p2) } #else /* not function graph compares against hits */ -static int function_stat_cmp(void *p1, void *p2) +static int function_stat_cmp(const void *p1, const void *p2) { - struct ftrace_profile *a = p1; - struct ftrace_profile *b = p2; + const struct ftrace_profile *a = p1; + const struct ftrace_profile *b = p2; if (a->counter < b->counter) return -1; @@ -600,59 +521,82 @@ static int function_stat_cmp(void *p1, void *p2) static int function_stat_headers(struct seq_file *m) { #ifdef CONFIG_FUNCTION_GRAPH_TRACER - seq_printf(m, " Function " - "Hit Time Avg s^2\n" - " -------- " - "--- ---- --- ---\n"); + seq_puts(m, " Function " + "Hit Time Avg s^2\n" + " -------- " + "--- ---- --- ---\n"); #else - seq_printf(m, " Function Hit\n" - " -------- ---\n"); + seq_puts(m, " Function Hit\n" + " -------- ---\n"); #endif return 0; } static int function_stat_show(struct seq_file *m, void *v) { + struct trace_array *tr = trace_get_global_array(); struct ftrace_profile *rec = v; + const char *refsymbol = NULL; char str[KSYM_SYMBOL_LEN]; - int ret = 0; #ifdef CONFIG_FUNCTION_GRAPH_TRACER static struct trace_seq s; unsigned long long avg; unsigned long long stddev; + unsigned long long stddev_denom; #endif - mutex_lock(&ftrace_profile_lock); + guard(mutex)(&ftrace_profile_lock); /* we raced with function_profile_reset() */ - if (unlikely(rec->counter == 0)) { - ret = -EBUSY; - goto out; + if (unlikely(rec->counter == 0)) + return -EBUSY; + +#ifdef CONFIG_FUNCTION_GRAPH_TRACER + avg = div64_ul(rec->time, rec->counter); + if (tracing_thresh && (avg < tracing_thresh)) + return 0; +#endif + + if (tr->trace_flags & TRACE_ITER(PROF_TEXT_OFFSET)) { + unsigned long offset; + + if (core_kernel_text(rec->ip)) { + refsymbol = "_text"; + offset = rec->ip - (unsigned long)_text; + } else { + struct module *mod; + + guard(rcu)(); + mod = __module_text_address(rec->ip); + if (mod) { + refsymbol = mod->name; + /* Calculate offset from module's text entry address. */ + offset = rec->ip - (unsigned long)mod->mem[MOD_TEXT].base; + } + } + if (refsymbol) + snprintf(str, sizeof(str), " %s+%#lx", refsymbol, offset); } + if (!refsymbol) + kallsyms_lookup(rec->ip, NULL, NULL, NULL, str); - kallsyms_lookup(rec->ip, NULL, NULL, NULL, str); seq_printf(m, " %-30.30s %10lu", str, rec->counter); #ifdef CONFIG_FUNCTION_GRAPH_TRACER - seq_printf(m, " "); - avg = rec->time; - do_div(avg, rec->counter); + seq_puts(m, " "); - /* Sample standard deviation (s^2) */ - if (rec->counter <= 1) - stddev = 0; - else { - /* - * Apply Welford's method: - * s^2 = 1 / (n * (n-1)) * (n * \Sum (x_i)^2 - (\Sum x_i)^2) - */ + /* + * Variance formula: + * s^2 = 1 / (n * (n-1)) * (n * \Sum (x_i)^2 - (\Sum x_i)^2) + * Maybe Welford's method is better here? + * Divide only by 1000 for ns^2 -> us^2 conversion. + * trace_print_graph_duration will divide by 1000 again. + */ + stddev = 0; + stddev_denom = rec->counter * (rec->counter - 1) * 1000; + if (stddev_denom) { stddev = rec->counter * rec->time_squared - rec->time * rec->time; - - /* - * Divide only 1000 for ns^2 -> us^2 conversion. - * trace_print_graph_duration will divide 1000 again. - */ - do_div(stddev, rec->counter * (rec->counter - 1) * 1000); + stddev = div64_ul(stddev, stddev_denom); } trace_seq_init(&s); @@ -664,10 +608,8 @@ static int function_stat_show(struct seq_file *m, void *v) trace_print_seq(m, &s); #endif seq_putc(m, '\n'); -out: - mutex_unlock(&ftrace_profile_lock); - return ret; + return 0; } static void ftrace_profile_reset(struct ftrace_profile_stat *stat) @@ -686,7 +628,7 @@ static void ftrace_profile_reset(struct ftrace_profile_stat *stat) FTRACE_PROFILE_HASH_SIZE * sizeof(struct hlist_head)); } -int ftrace_profile_pages_init(struct ftrace_profile_stat *stat) +static int ftrace_profile_pages_init(struct ftrace_profile_stat *stat) { struct ftrace_profile_page *pg; int functions; @@ -761,7 +703,7 @@ static int ftrace_profile_init_cpu(int cpu) */ size = FTRACE_PROFILE_HASH_SIZE; - stat->hash = kzalloc(sizeof(struct hlist_head) * size, GFP_KERNEL); + stat->hash = kcalloc(size, sizeof(struct hlist_head), GFP_KERNEL); if (!stat->hash) return -ENOMEM; @@ -781,7 +723,7 @@ static int ftrace_profile_init(void) int cpu; int ret = 0; - for_each_online_cpu(cpu) { + for_each_possible_cpu(cpu) { ret = ftrace_profile_init_cpu(cpu); if (ret) break; @@ -859,69 +801,109 @@ ftrace_profile_alloc(struct ftrace_profile_stat *stat, unsigned long ip) static void function_profile_call(unsigned long ip, unsigned long parent_ip, - struct ftrace_ops *ops, struct pt_regs *regs) + struct ftrace_ops *ops, struct ftrace_regs *fregs) { struct ftrace_profile_stat *stat; struct ftrace_profile *rec; - unsigned long flags; if (!ftrace_profile_enabled) return; - local_irq_save(flags); + guard(preempt_notrace)(); - stat = &__get_cpu_var(ftrace_profile_stats); + stat = this_cpu_ptr(&ftrace_profile_stats); if (!stat->hash || !ftrace_profile_enabled) - goto out; + return; rec = ftrace_find_profiled_func(stat, ip); if (!rec) { rec = ftrace_profile_alloc(stat, ip); if (!rec) - goto out; + return; } rec->counter++; - out: - local_irq_restore(flags); } #ifdef CONFIG_FUNCTION_GRAPH_TRACER -static int profile_graph_entry(struct ftrace_graph_ent *trace) +static bool fgraph_graph_time = true; + +void ftrace_graph_graph_time_control(bool enable) { + fgraph_graph_time = enable; +} + +struct profile_fgraph_data { + unsigned long long calltime; + unsigned long long subtime; + unsigned long long sleeptime; +}; + +static int profile_graph_entry(struct ftrace_graph_ent *trace, + struct fgraph_ops *gops, + struct ftrace_regs *fregs) +{ + struct profile_fgraph_data *profile_data; + function_profile_call(trace->func, 0, NULL, NULL); + + /* If function graph is shutting down, ret_stack can be NULL */ + if (!current->ret_stack) + return 0; + + profile_data = fgraph_reserve_data(gops->idx, sizeof(*profile_data)); + if (!profile_data) + return 0; + + profile_data->subtime = 0; + profile_data->sleeptime = current->ftrace_sleeptime; + profile_data->calltime = trace_clock_local(); + return 1; } -static void profile_graph_return(struct ftrace_graph_ret *trace) +bool fprofile_no_sleep_time; + +static void profile_graph_return(struct ftrace_graph_ret *trace, + struct fgraph_ops *gops, + struct ftrace_regs *fregs) { + struct profile_fgraph_data *profile_data; struct ftrace_profile_stat *stat; unsigned long long calltime; + unsigned long long rettime = trace_clock_local(); struct ftrace_profile *rec; - unsigned long flags; + int size; - local_irq_save(flags); - stat = &__get_cpu_var(ftrace_profile_stats); + guard(preempt_notrace)(); + + stat = this_cpu_ptr(&ftrace_profile_stats); if (!stat->hash || !ftrace_profile_enabled) - goto out; + return; + + profile_data = fgraph_retrieve_data(gops->idx, &size); /* If the calltime was zero'd ignore it */ - if (!trace->calltime) - goto out; + if (!profile_data || !profile_data->calltime) + return; - calltime = trace->rettime - trace->calltime; + calltime = rettime - profile_data->calltime; - if (!(trace_flags & TRACE_ITER_GRAPH_TIME)) { - int index; + if (fprofile_no_sleep_time) { + if (current->ftrace_sleeptime) + calltime -= current->ftrace_sleeptime - profile_data->sleeptime; + } - index = trace->depth; + if (!fgraph_graph_time) { + struct profile_fgraph_data *parent_data; /* Append this call time to the parent time to subtract */ - if (index) - current->ret_stack[index - 1].subtime += calltime; + parent_data = fgraph_retrieve_parent_data(gops->idx, &size, 1); + if (parent_data) + parent_data->subtime += calltime; - if (current->ret_stack[index].subtime < calltime) - calltime -= current->ret_stack[index].subtime; + if (profile_data->subtime && profile_data->subtime < calltime) + calltime -= profile_data->subtime; else calltime = 0; } @@ -931,30 +913,31 @@ static void profile_graph_return(struct ftrace_graph_ret *trace) rec->time += calltime; rec->time_squared += calltime * calltime; } - - out: - local_irq_restore(flags); } +static struct fgraph_ops fprofiler_ops = { + .entryfunc = &profile_graph_entry, + .retfunc = &profile_graph_return, +}; + static int register_ftrace_profiler(void) { - return register_ftrace_graph(&profile_graph_return, - &profile_graph_entry); + ftrace_ops_set_global_filter(&fprofiler_ops.ops); + return register_ftrace_graph(&fprofiler_ops); } static void unregister_ftrace_profiler(void) { - unregister_ftrace_graph(); + unregister_ftrace_graph(&fprofiler_ops); } #else static struct ftrace_ops ftrace_profile_ops __read_mostly = { .func = function_profile_call, - .flags = FTRACE_OPS_FL_RECURSION_SAFE | FTRACE_OPS_FL_INITIALIZED, - INIT_REGEX_LOCK(ftrace_profile_ops) }; static int register_ftrace_profiler(void) { + ftrace_ops_set_global_filter(&ftrace_profile_ops); return register_ftrace_function(&ftrace_profile_ops); } @@ -977,32 +960,26 @@ ftrace_profile_write(struct file *filp, const char __user *ubuf, val = !!val; - mutex_lock(&ftrace_profile_lock); + guard(mutex)(&ftrace_profile_lock); if (ftrace_profile_enabled ^ val) { if (val) { ret = ftrace_profile_init(); - if (ret < 0) { - cnt = ret; - goto out; - } + if (ret < 0) + return ret; ret = register_ftrace_profiler(); - if (ret < 0) { - cnt = ret; - goto out; - } + if (ret < 0) + return ret; ftrace_profile_enabled = 1; } else { ftrace_profile_enabled = 0; /* * unregister_ftrace_profiler calls stop_machine - * so this acts like an synchronize_sched. + * so this acts like an synchronize_rcu. */ unregister_ftrace_profiler(); } } - out: - mutex_unlock(&ftrace_profile_lock); *ppos += cnt; @@ -1037,10 +1014,9 @@ static struct tracer_stat function_stats __initdata = { .stat_show = function_stat_show }; -static __init void ftrace_profile_debugfs(struct dentry *d_tracer) +static __init void ftrace_profile_tracefs(struct dentry *d_tracer) { struct ftrace_profile_stat *stat; - struct dentry *entry; char *name; int ret; int cpu; @@ -1048,8 +1024,7 @@ static __init void ftrace_profile_debugfs(struct dentry *d_tracer) for_each_possible_cpu(cpu) { stat = &per_cpu(ftrace_profile_stats, cpu); - /* allocate enough for function name + cpu number */ - name = kmalloc(32, GFP_KERNEL); + name = kasprintf(GFP_KERNEL, "function%d", cpu); if (!name) { /* * The files created are permanent, if something happens @@ -1061,7 +1036,6 @@ static __init void ftrace_profile_debugfs(struct dentry *d_tracer) return; } stat->stat = function_stats; - snprintf(name, 32, "function%d", cpu); stat->stat.name = name; ret = register_stat_tracer(&stat->stat); if (ret) { @@ -1073,61 +1047,34 @@ static __init void ftrace_profile_debugfs(struct dentry *d_tracer) } } - entry = debugfs_create_file("function_profile_enabled", 0644, - d_tracer, NULL, &ftrace_profile_fops); - if (!entry) - pr_warning("Could not create debugfs " - "'function_profile_enabled' entry\n"); + trace_create_file("function_profile_enabled", + TRACE_MODE_WRITE, d_tracer, NULL, + &ftrace_profile_fops); } #else /* CONFIG_FUNCTION_PROFILER */ -static __init void ftrace_profile_debugfs(struct dentry *d_tracer) +static __init void ftrace_profile_tracefs(struct dentry *d_tracer) { } #endif /* CONFIG_FUNCTION_PROFILER */ -static struct pid * const ftrace_swapper_pid = &init_struct_pid; - -loff_t -ftrace_filter_lseek(struct file *file, loff_t offset, int whence) -{ - loff_t ret; - - if (file->f_mode & FMODE_READ) - ret = seq_lseek(file, offset, whence); - else - file->f_pos = ret = 1; - - return ret; -} - #ifdef CONFIG_DYNAMIC_FTRACE -#ifndef CONFIG_FTRACE_MCOUNT_RECORD -# error Dynamic ftrace depends on MCOUNT_RECORD -#endif +static struct ftrace_ops *removed_ops; -static struct hlist_head ftrace_func_hash[FTRACE_FUNC_HASHSIZE] __read_mostly; +/* + * Set when doing a global update, like enabling all recs or disabling them. + * It is not set when just updating a single ftrace_ops. + */ +static bool update_all_ops; struct ftrace_func_probe { - struct hlist_node node; - struct ftrace_probe_ops *ops; - unsigned long flags; - unsigned long ip; + struct ftrace_probe_ops *probe_ops; + struct ftrace_ops ops; + struct trace_array *tr; + struct list_head list; void *data; - struct list_head free_list; -}; - -struct ftrace_func_entry { - struct hlist_node hlist; - unsigned long ip; -}; - -struct ftrace_hash { - unsigned long size_bits; - struct hlist_head *buckets; - unsigned long count; - struct rcu_head rcu; + int ref; }; /* @@ -1142,52 +1089,88 @@ static const struct ftrace_hash empty_hash = { }; #define EMPTY_HASH ((struct ftrace_hash *)&empty_hash) -static struct ftrace_ops global_ops = { - .func = ftrace_stub, - .notrace_hash = EMPTY_HASH, - .filter_hash = EMPTY_HASH, - .flags = FTRACE_OPS_FL_RECURSION_SAFE | FTRACE_OPS_FL_INITIALIZED, - INIT_REGEX_LOCK(global_ops) +struct ftrace_ops global_ops = { + .func = ftrace_stub, + .local_hash.notrace_hash = EMPTY_HASH, + .local_hash.filter_hash = EMPTY_HASH, + INIT_OPS_HASH(global_ops) + .flags = FTRACE_OPS_FL_INITIALIZED | + FTRACE_OPS_FL_PID, }; +/* + * Used by the stack unwinder to know about dynamic ftrace trampolines. + */ +struct ftrace_ops *ftrace_ops_trampoline(unsigned long addr) +{ + struct ftrace_ops *op = NULL; + + /* + * Some of the ops may be dynamically allocated, + * they are freed after a synchronize_rcu(). + */ + preempt_disable_notrace(); + + do_for_each_ftrace_op(op, ftrace_ops_list) { + /* + * This is to check for dynamically allocated trampolines. + * Trampolines that are in kernel text will have + * core_kernel_text() return true. + */ + if (op->trampoline && op->trampoline_size) + if (addr >= op->trampoline && + addr < op->trampoline + op->trampoline_size) { + preempt_enable_notrace(); + return op; + } + } while_for_each_ftrace_op(op); + preempt_enable_notrace(); + + return NULL; +} + +/* + * This is used by __kernel_text_address() to return true if the + * address is on a dynamically allocated trampoline that would + * not return true for either core_kernel_text() or + * is_module_text_address(). + */ +bool is_ftrace_trampoline(unsigned long addr) +{ + return ftrace_ops_trampoline(addr) != NULL; +} + struct ftrace_page { struct ftrace_page *next; struct dyn_ftrace *records; int index; - int size; + int order; }; -static struct ftrace_page *ftrace_new_pgs; - #define ENTRY_SIZE sizeof(struct dyn_ftrace) #define ENTRIES_PER_PAGE (PAGE_SIZE / ENTRY_SIZE) -/* estimate from running different kernels */ -#define NR_TO_INIT 10000 - static struct ftrace_page *ftrace_pages_start; static struct ftrace_page *ftrace_pages; -static bool ftrace_hash_empty(struct ftrace_hash *hash) +static __always_inline unsigned long +ftrace_hash_key(struct ftrace_hash *hash, unsigned long ip) { - return !hash || !hash->count; + if (hash->size_bits > 0) + return hash_long(ip, hash->size_bits); + + return 0; } -static struct ftrace_func_entry * -ftrace_lookup_ip(struct ftrace_hash *hash, unsigned long ip) +/* Only use this function if ftrace_hash_empty() has already been tested */ +static __always_inline struct ftrace_func_entry * +__ftrace_lookup_ip(struct ftrace_hash *hash, unsigned long ip) { unsigned long key; struct ftrace_func_entry *entry; struct hlist_head *hhd; - if (ftrace_hash_empty(hash)) - return NULL; - - if (hash->size_bits > 0) - key = hash_long(ip, hash->size_bits); - else - key = 0; - + key = ftrace_hash_key(hash, ip); hhd = &hash->buckets[key]; hlist_for_each_entry_rcu_notrace(entry, hhd, hlist) { @@ -1197,34 +1180,50 @@ ftrace_lookup_ip(struct ftrace_hash *hash, unsigned long ip) return NULL; } +/** + * ftrace_lookup_ip - Test to see if an ip exists in an ftrace_hash + * @hash: The hash to look at + * @ip: The instruction pointer to test + * + * Search a given @hash to see if a given instruction pointer (@ip) + * exists in it. + * + * Returns: the entry that holds the @ip if found. NULL otherwise. + */ +struct ftrace_func_entry * +ftrace_lookup_ip(struct ftrace_hash *hash, unsigned long ip) +{ + if (ftrace_hash_empty(hash)) + return NULL; + + return __ftrace_lookup_ip(hash, ip); +} + static void __add_hash_entry(struct ftrace_hash *hash, struct ftrace_func_entry *entry) { struct hlist_head *hhd; unsigned long key; - if (hash->size_bits) - key = hash_long(entry->ip, hash->size_bits); - else - key = 0; - + key = ftrace_hash_key(hash, entry->ip); hhd = &hash->buckets[key]; hlist_add_head(&entry->hlist, hhd); hash->count++; } -static int add_hash_entry(struct ftrace_hash *hash, unsigned long ip) +static struct ftrace_func_entry * +add_hash_entry(struct ftrace_hash *hash, unsigned long ip) { struct ftrace_func_entry *entry; entry = kmalloc(sizeof(*entry), GFP_KERNEL); if (!entry) - return -ENOMEM; + return NULL; entry->ip = ip; __add_hash_entry(hash, entry); - return 0; + return entry; } static void @@ -1240,7 +1239,7 @@ static void remove_hash_entry(struct ftrace_hash *hash, struct ftrace_func_entry *entry) { - hlist_del(&entry->hlist); + hlist_del_rcu(&entry->hlist); hash->count--; } @@ -1263,6 +1262,28 @@ static void ftrace_hash_clear(struct ftrace_hash *hash) FTRACE_WARN_ON(hash->count); } +static void free_ftrace_mod(struct ftrace_mod_load *ftrace_mod) +{ + list_del(&ftrace_mod->list); + kfree(ftrace_mod->module); + kfree(ftrace_mod->func); + kfree(ftrace_mod); +} + +static void clear_ftrace_mod_list(struct list_head *head) +{ + struct ftrace_mod_load *p, *n; + + /* stack tracer isn't supported yet */ + if (!head) + return; + + mutex_lock(&ftrace_lock); + list_for_each_entry_safe(p, n, head, list) + free_ftrace_mod(p); + mutex_unlock(&ftrace_lock); +} + static void free_ftrace_hash(struct ftrace_hash *hash) { if (!hash || hash == EMPTY_HASH) @@ -1284,15 +1305,24 @@ static void free_ftrace_hash_rcu(struct ftrace_hash *hash) { if (!hash || hash == EMPTY_HASH) return; - call_rcu_sched(&hash->rcu, __free_ftrace_hash_rcu); + call_rcu(&hash->rcu, __free_ftrace_hash_rcu); } +/** + * ftrace_free_filter - remove all filters for an ftrace_ops + * @ops: the ops to remove the filters from + */ void ftrace_free_filter(struct ftrace_ops *ops) { ftrace_ops_init(ops); - free_ftrace_hash(ops->filter_hash); - free_ftrace_hash(ops->notrace_hash); + if (WARN_ON(ops->flags & FTRACE_OPS_FL_ENABLED)) + return; + free_ftrace_hash(ops->func_hash->filter_hash); + free_ftrace_hash(ops->func_hash->notrace_hash); + ops->func_hash->filter_hash = EMPTY_HASH; + ops->func_hash->notrace_hash = EMPTY_HASH; } +EXPORT_SYMBOL_GPL(ftrace_free_filter); static struct ftrace_hash *alloc_ftrace_hash(int size_bits) { @@ -1316,19 +1346,51 @@ static struct ftrace_hash *alloc_ftrace_hash(int size_bits) return hash; } +/* Used to save filters on functions for modules not loaded yet */ +static int ftrace_add_mod(struct trace_array *tr, + const char *func, const char *module, + int enable) +{ + struct ftrace_mod_load *ftrace_mod; + struct list_head *mod_head = enable ? &tr->mod_trace : &tr->mod_notrace; + + ftrace_mod = kzalloc(sizeof(*ftrace_mod), GFP_KERNEL); + if (!ftrace_mod) + return -ENOMEM; + + INIT_LIST_HEAD(&ftrace_mod->list); + ftrace_mod->func = kstrdup(func, GFP_KERNEL); + ftrace_mod->module = kstrdup(module, GFP_KERNEL); + ftrace_mod->enable = enable; + + if (!ftrace_mod->func || !ftrace_mod->module) + goto out_free; + + list_add(&ftrace_mod->list, mod_head); + + return 0; + + out_free: + free_ftrace_mod(ftrace_mod); + + return -ENOMEM; +} + static struct ftrace_hash * alloc_and_copy_ftrace_hash(int size_bits, struct ftrace_hash *hash) { struct ftrace_func_entry *entry; struct ftrace_hash *new_hash; int size; - int ret; int i; new_hash = alloc_ftrace_hash(size_bits); if (!new_hash) return NULL; + if (hash) + new_hash->flags = hash->flags; + /* Empty hash? */ if (ftrace_hash_empty(hash)) return new_hash; @@ -1336,8 +1398,7 @@ alloc_and_copy_ftrace_hash(int size_bits, struct ftrace_hash *hash) size = 1 << hash->size_bits; for (i = 0; i < size; i++) { hlist_for_each_entry(entry, &hash->buckets[i], hlist) { - ret = add_hash_entry(new_hash, entry->ip); - if (ret < 0) + if (add_hash_entry(new_hash, entry->ip) == NULL) goto free_hash; } } @@ -1351,57 +1412,40 @@ alloc_and_copy_ftrace_hash(int size_bits, struct ftrace_hash *hash) return NULL; } -static void -ftrace_hash_rec_disable(struct ftrace_ops *ops, int filter_hash); -static void -ftrace_hash_rec_enable(struct ftrace_ops *ops, int filter_hash); +static void ftrace_hash_rec_disable_modify(struct ftrace_ops *ops); +static void ftrace_hash_rec_enable_modify(struct ftrace_ops *ops); -static int -ftrace_hash_move(struct ftrace_ops *ops, int enable, - struct ftrace_hash **dst, struct ftrace_hash *src) +static int ftrace_hash_ipmodify_update(struct ftrace_ops *ops, + struct ftrace_hash *new_hash); + +/* + * Allocate a new hash and remove entries from @src and move them to the new hash. + * On success, the @src hash will be empty and should be freed. + */ +static struct ftrace_hash *__move_hash(struct ftrace_hash *src, int size) { struct ftrace_func_entry *entry; - struct hlist_node *tn; - struct hlist_head *hhd; - struct ftrace_hash *old_hash; struct ftrace_hash *new_hash; - int size = src->count; + struct hlist_head *hhd; + struct hlist_node *tn; int bits = 0; - int ret; int i; /* - * Remove the current set, update the hash and add - * them back. - */ - ftrace_hash_rec_disable(ops, enable); - - /* - * If the new source is empty, just free dst and assign it - * the empty_hash. - */ - if (!src->count) { - free_ftrace_hash_rcu(*dst); - rcu_assign_pointer(*dst, EMPTY_HASH); - /* still need to update the function records */ - ret = 0; - goto out; - } - - /* - * Make the hash size about 1/2 the # found + * Use around half the size (max bit of it), but + * a minimum of 2 is fine (as size of 0 or 1 both give 1 for bits). */ - for (size /= 2; size; size >>= 1) - bits++; + bits = fls(size / 2); /* Don't allocate too much */ if (bits > FTRACE_HASH_MAX_BITS) bits = FTRACE_HASH_MAX_BITS; - ret = -ENOMEM; new_hash = alloc_ftrace_hash(bits); if (!new_hash) - goto out; + return NULL; + + new_hash->flags = src->flags; size = 1 << src->size_bits; for (i = 0; i < size; i++) { @@ -1411,21 +1455,95 @@ ftrace_hash_move(struct ftrace_ops *ops, int enable, __add_hash_entry(new_hash, entry); } } + return new_hash; +} - old_hash = *dst; - rcu_assign_pointer(*dst, new_hash); - free_ftrace_hash_rcu(old_hash); +/* Move the @src entries to a newly allocated hash */ +static struct ftrace_hash * +__ftrace_hash_move(struct ftrace_hash *src) +{ + int size = src->count; - ret = 0; - out: /* - * Enable regardless of ret: - * On success, we enable the new hash. - * On failure, we re-enable the original hash. + * If the new source is empty, just return the empty_hash. */ - ftrace_hash_rec_enable(ops, enable); + if (ftrace_hash_empty(src)) + return EMPTY_HASH; - return ret; + return __move_hash(src, size); +} + +/** + * ftrace_hash_move - move a new hash to a filter and do updates + * @ops: The ops with the hash that @dst points to + * @enable: True if for the filter hash, false for the notrace hash + * @dst: Points to the @ops hash that should be updated + * @src: The hash to update @dst with + * + * This is called when an ftrace_ops hash is being updated and the + * the kernel needs to reflect this. Note, this only updates the kernel + * function callbacks if the @ops is enabled (not to be confused with + * @enable above). If the @ops is enabled, its hash determines what + * callbacks get called. This function gets called when the @ops hash + * is updated and it requires new callbacks. + * + * On success the elements of @src is moved to @dst, and @dst is updated + * properly, as well as the functions determined by the @ops hashes + * are now calling the @ops callback function. + * + * Regardless of return type, @src should be freed with free_ftrace_hash(). + */ +static int +ftrace_hash_move(struct ftrace_ops *ops, int enable, + struct ftrace_hash **dst, struct ftrace_hash *src) +{ + struct ftrace_hash *new_hash; + int ret; + + /* Reject setting notrace hash on IPMODIFY ftrace_ops */ + if (ops->flags & FTRACE_OPS_FL_IPMODIFY && !enable) + return -EINVAL; + + new_hash = __ftrace_hash_move(src); + if (!new_hash) + return -ENOMEM; + + /* Make sure this can be applied if it is IPMODIFY ftrace_ops */ + if (enable) { + /* IPMODIFY should be updated only when filter_hash updating */ + ret = ftrace_hash_ipmodify_update(ops, new_hash); + if (ret < 0) { + free_ftrace_hash(new_hash); + return ret; + } + } + + /* + * Remove the current set, update the hash and add + * them back. + */ + ftrace_hash_rec_disable_modify(ops); + + rcu_assign_pointer(*dst, new_hash); + + ftrace_hash_rec_enable_modify(ops); + + return 0; +} + +static bool hash_contains_ip(unsigned long ip, + struct ftrace_ops_hash *hash) +{ + /* + * The function record is a match if it exists in the filter + * hash and not in the notrace hash. Note, an empty hash is + * considered a match for the filter hash, but an empty + * notrace hash is considered not in the notrace hash. + */ + return (ftrace_hash_empty(hash->filter_hash) || + __ftrace_lookup_ip(hash->filter_hash, ip)) && + (ftrace_hash_empty(hash->notrace_hash) || + !__ftrace_lookup_ip(hash->notrace_hash, ip)); } /* @@ -1438,22 +1556,28 @@ ftrace_hash_move(struct ftrace_ops *ops, int enable, * the ip is not in the ops->notrace_hash. * * This needs to be called with preemption disabled as - * the hashes are freed with call_rcu_sched(). + * the hashes are freed with call_rcu(). */ -static int -ftrace_ops_test(struct ftrace_ops *ops, unsigned long ip) +int +ftrace_ops_test(struct ftrace_ops *ops, unsigned long ip, void *regs) { - struct ftrace_hash *filter_hash; - struct ftrace_hash *notrace_hash; + struct ftrace_ops_hash hash; int ret; - filter_hash = rcu_dereference_raw_notrace(ops->filter_hash); - notrace_hash = rcu_dereference_raw_notrace(ops->notrace_hash); +#ifdef CONFIG_DYNAMIC_FTRACE_WITH_REGS + /* + * There's a small race when adding ops that the ftrace handler + * that wants regs, may be called without them. We can not + * allow that handler to be called if regs is NULL. + */ + if (regs == NULL && (ops->flags & FTRACE_OPS_FL_SAVE_REGS)) + return 0; +#endif + + rcu_assign_pointer(hash.filter_hash, ops->func_hash->filter_hash); + rcu_assign_pointer(hash.notrace_hash, ops->func_hash->notrace_hash); - if ((ftrace_hash_empty(filter_hash) || - ftrace_lookup_ip(filter_hash, ip)) && - (ftrace_hash_empty(notrace_hash) || - !ftrace_lookup_ip(notrace_hash, ip))) + if (hash_contains_ip(ip, &hash)) ret = 1; else ret = 0; @@ -1488,41 +1612,80 @@ static int ftrace_cmp_recs(const void *a, const void *b) return 0; } -static unsigned long ftrace_location_range(unsigned long start, unsigned long end) +static struct dyn_ftrace *lookup_rec(unsigned long start, unsigned long end) { struct ftrace_page *pg; - struct dyn_ftrace *rec; + struct dyn_ftrace *rec = NULL; struct dyn_ftrace key; key.ip = start; key.flags = end; /* overload flags, as it is unsigned long */ for (pg = ftrace_pages_start; pg; pg = pg->next) { - if (end < pg->records[0].ip || + if (pg->index == 0 || + end < pg->records[0].ip || start >= (pg->records[pg->index - 1].ip + MCOUNT_INSN_SIZE)) continue; rec = bsearch(&key, pg->records, pg->index, sizeof(struct dyn_ftrace), ftrace_cmp_recs); if (rec) - return rec->ip; + break; } + return rec; +} - return 0; +/** + * ftrace_location_range - return the first address of a traced location + * if it touches the given ip range + * @start: start of range to search. + * @end: end of range to search (inclusive). @end points to the last byte + * to check. + * + * Returns: rec->ip if the related ftrace location is a least partly within + * the given address range. That is, the first address of the instruction + * that is either a NOP or call to the function tracer. It checks the ftrace + * internal tables to determine if the address belongs or not. + */ +unsigned long ftrace_location_range(unsigned long start, unsigned long end) +{ + struct dyn_ftrace *rec; + unsigned long ip = 0; + + rcu_read_lock(); + rec = lookup_rec(start, end); + if (rec) + ip = rec->ip; + rcu_read_unlock(); + + return ip; } /** - * ftrace_location - return true if the ip giving is a traced location + * ftrace_location - return the ftrace location * @ip: the instruction pointer to check * - * Returns rec->ip if @ip given is a pointer to a ftrace location. - * That is, the instruction that is either a NOP or call to - * the function tracer. It checks the ftrace internal tables to - * determine if the address belongs or not. + * Returns: + * * If @ip matches the ftrace location, return @ip. + * * If @ip matches sym+0, return sym's ftrace location. + * * Otherwise, return 0. */ unsigned long ftrace_location(unsigned long ip) { - return ftrace_location_range(ip, ip); + unsigned long loc; + unsigned long offset; + unsigned long size; + + loc = ftrace_location_range(ip, ip); + if (!loc) { + if (!kallsyms_lookup_size_offset(ip, &size, &offset)) + return 0; + + /* map sym+0 to __fentry__ */ + if (!offset) + loc = ftrace_location_range(ip, ip + size - 1); + } + return loc; } /** @@ -1530,12 +1693,12 @@ unsigned long ftrace_location(unsigned long ip) * @start: start of range to search * @end: end of range to search (inclusive). @end points to the last byte to check. * - * Returns 1 if @start and @end contains a ftrace location. + * Returns: 1 if @start and @end contains a ftrace location. * That is, the instruction that is either a NOP or call to * the function tracer. It checks the ftrace internal tables to * determine if the address belongs or not. */ -int ftrace_text_reserved(void *start, void *end) +int ftrace_text_reserved(const void *start, const void *end) { unsigned long ret; @@ -1545,72 +1708,103 @@ int ftrace_text_reserved(void *start, void *end) return (int)!!ret; } -static void __ftrace_hash_rec_update(struct ftrace_ops *ops, - int filter_hash, +/* Test if ops registered to this rec needs regs */ +static bool test_rec_ops_needs_regs(struct dyn_ftrace *rec) +{ + struct ftrace_ops *ops; + bool keep_regs = false; + + for (ops = ftrace_ops_list; + ops != &ftrace_list_end; ops = ops->next) { + /* pass rec in as regs to have non-NULL val */ + if (ftrace_ops_test(ops, rec->ip, rec)) { + if (ops->flags & FTRACE_OPS_FL_SAVE_REGS) { + keep_regs = true; + break; + } + } + } + + return keep_regs; +} + +static struct ftrace_ops * +ftrace_find_tramp_ops_any(struct dyn_ftrace *rec); +static struct ftrace_ops * +ftrace_find_tramp_ops_any_other(struct dyn_ftrace *rec, struct ftrace_ops *op_exclude); +static struct ftrace_ops * +ftrace_find_tramp_ops_next(struct dyn_ftrace *rec, struct ftrace_ops *ops); + +static bool skip_record(struct dyn_ftrace *rec) +{ + /* + * At boot up, weak functions are set to disable. Function tracing + * can be enabled before they are, and they still need to be disabled now. + * If the record is disabled, still continue if it is marked as already + * enabled (this is needed to keep the accounting working). + */ + return rec->flags & FTRACE_FL_DISABLED && + !(rec->flags & FTRACE_FL_ENABLED); +} + +/* + * This is the main engine to the ftrace updates to the dyn_ftrace records. + * + * It will iterate through all the available ftrace functions + * (the ones that ftrace can have callbacks to) and set the flags + * in the associated dyn_ftrace records. + * + * @inc: If true, the functions associated to @ops are added to + * the dyn_ftrace records, otherwise they are removed. + */ +static bool __ftrace_hash_rec_update(struct ftrace_ops *ops, bool inc) { struct ftrace_hash *hash; - struct ftrace_hash *other_hash; + struct ftrace_hash *notrace_hash; struct ftrace_page *pg; struct dyn_ftrace *rec; + bool update = false; int count = 0; - int all = 0; + int all = false; /* Only update if the ops has been registered */ if (!(ops->flags & FTRACE_OPS_FL_ENABLED)) - return; + return false; /* - * In the filter_hash case: * If the count is zero, we update all records. * Otherwise we just update the items in the hash. - * - * In the notrace_hash case: - * We enable the update in the hash. - * As disabling notrace means enabling the tracing, - * and enabling notrace means disabling, the inc variable - * gets inversed. */ - if (filter_hash) { - hash = ops->filter_hash; - other_hash = ops->notrace_hash; - if (ftrace_hash_empty(hash)) - all = 1; - } else { - inc = !inc; - hash = ops->notrace_hash; - other_hash = ops->filter_hash; - /* - * If the notrace hash has no items, - * then there's nothing to do. - */ - if (ftrace_hash_empty(hash)) - return; - } + hash = ops->func_hash->filter_hash; + notrace_hash = ops->func_hash->notrace_hash; + if (ftrace_hash_empty(hash)) + all = true; do_for_each_ftrace_rec(pg, rec) { - int in_other_hash = 0; + int in_notrace_hash = 0; int in_hash = 0; int match = 0; + if (skip_record(rec)) + continue; + if (all) { /* * Only the filter_hash affects all records. * Update if the record is not in the notrace hash. */ - if (!other_hash || !ftrace_lookup_ip(other_hash, rec->ip)) + if (!notrace_hash || !ftrace_lookup_ip(notrace_hash, rec->ip)) match = 1; } else { in_hash = !!ftrace_lookup_ip(hash, rec->ip); - in_other_hash = !!ftrace_lookup_ip(other_hash, rec->ip); + in_notrace_hash = !!ftrace_lookup_ip(notrace_hash, rec->ip); /* - * + * We want to match all functions that are in the hash but + * not in the other hash. */ - if (filter_hash && in_hash && !in_other_hash) - match = 1; - else if (!filter_hash && in_hash && - (in_other_hash || ftrace_hash_empty(other_hash))) + if (in_hash && !in_notrace_hash) match = 1; } if (!match) @@ -1618,8 +1812,28 @@ static void __ftrace_hash_rec_update(struct ftrace_ops *ops, if (inc) { rec->flags++; - if (FTRACE_WARN_ON((rec->flags & ~FTRACE_FL_MASK) == FTRACE_REF_MAX)) - return; + if (FTRACE_WARN_ON(ftrace_rec_count(rec) == FTRACE_REF_MAX)) + return false; + + if (ops->flags & FTRACE_OPS_FL_DIRECT) + rec->flags |= FTRACE_FL_DIRECT; + + /* + * If there's only a single callback registered to a + * function, and the ops has a trampoline registered + * for it, then we can call it directly. + */ + if (ftrace_rec_count(rec) == 1 && ops->trampoline) + rec->flags |= FTRACE_FL_TRAMP; + else + /* + * If we are adding another function callback + * to this function, and the previous had a + * custom trampoline in use, then we need to go + * back to the default trampoline. + */ + rec->flags &= ~FTRACE_FL_TRAMP; + /* * If any ops wants regs saved for this function * then all ops will get saved regs. @@ -1627,82 +1841,422 @@ static void __ftrace_hash_rec_update(struct ftrace_ops *ops, if (ops->flags & FTRACE_OPS_FL_SAVE_REGS) rec->flags |= FTRACE_FL_REGS; } else { - if (FTRACE_WARN_ON((rec->flags & ~FTRACE_FL_MASK) == 0)) - return; + if (FTRACE_WARN_ON(ftrace_rec_count(rec) == 0)) + return false; rec->flags--; + + /* + * Only the internal direct_ops should have the + * DIRECT flag set. Thus, if it is removing a + * function, then that function should no longer + * be direct. + */ + if (ops->flags & FTRACE_OPS_FL_DIRECT) + rec->flags &= ~FTRACE_FL_DIRECT; + + /* + * If the rec had REGS enabled and the ops that is + * being removed had REGS set, then see if there is + * still any ops for this record that wants regs. + * If not, we can stop recording them. + */ + if (ftrace_rec_count(rec) > 0 && + rec->flags & FTRACE_FL_REGS && + ops->flags & FTRACE_OPS_FL_SAVE_REGS) { + if (!test_rec_ops_needs_regs(rec)) + rec->flags &= ~FTRACE_FL_REGS; + } + + /* + * The TRAMP needs to be set only if rec count + * is decremented to one, and the ops that is + * left has a trampoline. As TRAMP can only be + * enabled if there is only a single ops attached + * to it. + */ + if (ftrace_rec_count(rec) == 1 && + ftrace_find_tramp_ops_any_other(rec, ops)) + rec->flags |= FTRACE_FL_TRAMP; + else + rec->flags &= ~FTRACE_FL_TRAMP; + + /* + * flags will be cleared in ftrace_check_record() + * if rec count is zero. + */ } + + /* + * If the rec has a single associated ops, and ops->func can be + * called directly, allow the call site to call via the ops. + */ + if (IS_ENABLED(CONFIG_DYNAMIC_FTRACE_WITH_CALL_OPS) && + ftrace_rec_count(rec) == 1 && + ftrace_ops_get_func(ops) == ops->func) + rec->flags |= FTRACE_FL_CALL_OPS; + else + rec->flags &= ~FTRACE_FL_CALL_OPS; + count++; + + /* Must match FTRACE_UPDATE_CALLS in ftrace_modify_all_code() */ + update |= ftrace_test_record(rec, true) != FTRACE_UPDATE_IGNORE; + /* Shortcut, if we handled all records, we are done. */ if (!all && count == hash->count) - return; + return update; } while_for_each_ftrace_rec(); + + return update; +} + +/* + * This is called when an ops is removed from tracing. It will decrement + * the counters of the dyn_ftrace records for all the functions that + * the @ops attached to. + */ +static bool ftrace_hash_rec_disable(struct ftrace_ops *ops) +{ + return __ftrace_hash_rec_update(ops, false); +} + +/* + * This is called when an ops is added to tracing. It will increment + * the counters of the dyn_ftrace records for all the functions that + * the @ops attached to. + */ +static bool ftrace_hash_rec_enable(struct ftrace_ops *ops) +{ + return __ftrace_hash_rec_update(ops, true); } -static void ftrace_hash_rec_disable(struct ftrace_ops *ops, - int filter_hash) +/* + * This function will update what functions @ops traces when its filter + * changes. + * + * The @inc states if the @ops callbacks are going to be added or removed. + * When one of the @ops hashes are updated to a "new_hash" the dyn_ftrace + * records are update via: + * + * ftrace_hash_rec_disable_modify(ops); + * ops->hash = new_hash + * ftrace_hash_rec_enable_modify(ops); + * + * Where the @ops is removed from all the records it is tracing using + * its old hash. The @ops hash is updated to the new hash, and then + * the @ops is added back to the records so that it is tracing all + * the new functions. + */ +static void ftrace_hash_rec_update_modify(struct ftrace_ops *ops, bool inc) { - __ftrace_hash_rec_update(ops, filter_hash, 0); + struct ftrace_ops *op; + + __ftrace_hash_rec_update(ops, inc); + + if (ops->func_hash != &global_ops.local_hash) + return; + + /* + * If the ops shares the global_ops hash, then we need to update + * all ops that are enabled and use this hash. + */ + do_for_each_ftrace_op(op, ftrace_ops_list) { + /* Already done */ + if (op == ops) + continue; + if (op->func_hash == &global_ops.local_hash) + __ftrace_hash_rec_update(op, inc); + } while_for_each_ftrace_op(op); } -static void ftrace_hash_rec_enable(struct ftrace_ops *ops, - int filter_hash) +static void ftrace_hash_rec_disable_modify(struct ftrace_ops *ops) { - __ftrace_hash_rec_update(ops, filter_hash, 1); + ftrace_hash_rec_update_modify(ops, false); } -static void print_ip_ins(const char *fmt, unsigned char *p) +static void ftrace_hash_rec_enable_modify(struct ftrace_ops *ops) { - int i; + ftrace_hash_rec_update_modify(ops, true); +} + +/* + * Try to update IPMODIFY flag on each ftrace_rec. Return 0 if it is OK + * or no-needed to update, -EBUSY if it detects a conflict of the flag + * on a ftrace_rec, and -EINVAL if the new_hash tries to trace all recs. + * Note that old_hash and new_hash has below meanings + * - If the hash is NULL, it hits all recs (if IPMODIFY is set, this is rejected) + * - If the hash is EMPTY_HASH, it hits nothing + * - Anything else hits the recs which match the hash entries. + * + * DIRECT ops does not have IPMODIFY flag, but we still need to check it + * against functions with FTRACE_FL_IPMODIFY. If there is any overlap, call + * ops_func(SHARE_IPMODIFY_SELF) to make sure current ops can share with + * IPMODIFY. If ops_func(SHARE_IPMODIFY_SELF) returns non-zero, propagate + * the return value to the caller and eventually to the owner of the DIRECT + * ops. + */ +static int __ftrace_hash_update_ipmodify(struct ftrace_ops *ops, + struct ftrace_hash *old_hash, + struct ftrace_hash *new_hash, + bool update_target) +{ + struct ftrace_page *pg; + struct dyn_ftrace *rec, *end = NULL; + int in_old, in_new; + bool is_ipmodify, is_direct; + + /* Only update if the ops has been registered */ + if (!(ops->flags & FTRACE_OPS_FL_ENABLED)) + return 0; + + is_ipmodify = ops->flags & FTRACE_OPS_FL_IPMODIFY; + is_direct = ops->flags & FTRACE_OPS_FL_DIRECT; + + /* neither IPMODIFY nor DIRECT, skip */ + if (!is_ipmodify && !is_direct) + return 0; + + if (WARN_ON_ONCE(is_ipmodify && is_direct)) + return 0; + + /* + * Since the IPMODIFY and DIRECT are very address sensitive + * actions, we do not allow ftrace_ops to set all functions to new + * hash. + */ + if (!new_hash || !old_hash) + return -EINVAL; + + /* Update rec->flags */ + do_for_each_ftrace_rec(pg, rec) { + + if (rec->flags & FTRACE_FL_DISABLED) + continue; + + /* + * Unless we are updating the target of a direct function, + * we only need to update differences of filter_hash + */ + in_old = !!ftrace_lookup_ip(old_hash, rec->ip); + in_new = !!ftrace_lookup_ip(new_hash, rec->ip); + if (!update_target && (in_old == in_new)) + continue; + + if (in_new) { + if (rec->flags & FTRACE_FL_IPMODIFY) { + int ret; + + /* Cannot have two ipmodify on same rec */ + if (is_ipmodify) + goto rollback; + + /* + * If this is called by __modify_ftrace_direct() + * then it is only changing where the direct + * pointer is jumping to, and the record already + * points to a direct trampoline. If it isn't, + * then it is a bug to update ipmodify on a direct + * caller. + */ + FTRACE_WARN_ON(!update_target && + (rec->flags & FTRACE_FL_DIRECT)); + + /* + * Another ops with IPMODIFY is already + * attached. We are now attaching a direct + * ops. Run SHARE_IPMODIFY_SELF, to check + * whether sharing is supported. + */ + if (!ops->ops_func) + return -EBUSY; + ret = ops->ops_func(ops, FTRACE_OPS_CMD_ENABLE_SHARE_IPMODIFY_SELF); + if (ret) + return ret; + } else if (is_ipmodify) { + rec->flags |= FTRACE_FL_IPMODIFY; + } + } else if (is_ipmodify) { + rec->flags &= ~FTRACE_FL_IPMODIFY; + } + } while_for_each_ftrace_rec(); + + return 0; + +rollback: + end = rec; + + /* Roll back what we did above */ + do_for_each_ftrace_rec(pg, rec) { + + if (rec->flags & FTRACE_FL_DISABLED) + continue; + + if (rec == end) + return -EBUSY; + + in_old = !!ftrace_lookup_ip(old_hash, rec->ip); + in_new = !!ftrace_lookup_ip(new_hash, rec->ip); + if (in_old == in_new) + continue; + + if (in_new) + rec->flags &= ~FTRACE_FL_IPMODIFY; + else + rec->flags |= FTRACE_FL_IPMODIFY; + } while_for_each_ftrace_rec(); + + return -EBUSY; +} + +static int ftrace_hash_ipmodify_enable(struct ftrace_ops *ops) +{ + struct ftrace_hash *hash = ops->func_hash->filter_hash; + + if (ftrace_hash_empty(hash)) + hash = NULL; + + return __ftrace_hash_update_ipmodify(ops, EMPTY_HASH, hash, false); +} + +/* Disabling always succeeds */ +static void ftrace_hash_ipmodify_disable(struct ftrace_ops *ops) +{ + struct ftrace_hash *hash = ops->func_hash->filter_hash; + + if (ftrace_hash_empty(hash)) + hash = NULL; + + __ftrace_hash_update_ipmodify(ops, hash, EMPTY_HASH, false); +} + +static int ftrace_hash_ipmodify_update(struct ftrace_ops *ops, + struct ftrace_hash *new_hash) +{ + struct ftrace_hash *old_hash = ops->func_hash->filter_hash; + + if (ftrace_hash_empty(old_hash)) + old_hash = NULL; + + if (ftrace_hash_empty(new_hash)) + new_hash = NULL; + + return __ftrace_hash_update_ipmodify(ops, old_hash, new_hash, false); +} + +static void print_ip_ins(const char *fmt, const unsigned char *p) +{ + char ins[MCOUNT_INSN_SIZE]; + + if (copy_from_kernel_nofault(ins, p, MCOUNT_INSN_SIZE)) { + printk(KERN_CONT "%s[FAULT] %px\n", fmt, p); + return; + } printk(KERN_CONT "%s", fmt); + pr_cont("%*phC", MCOUNT_INSN_SIZE, ins); +} + +enum ftrace_bug_type ftrace_bug_type; +const void *ftrace_expected; - for (i = 0; i < MCOUNT_INSN_SIZE; i++) - printk(KERN_CONT "%s%02x", i ? ":" : "", p[i]); +static void print_bug_type(void) +{ + switch (ftrace_bug_type) { + case FTRACE_BUG_UNKNOWN: + break; + case FTRACE_BUG_INIT: + pr_info("Initializing ftrace call sites\n"); + break; + case FTRACE_BUG_NOP: + pr_info("Setting ftrace call site to NOP\n"); + break; + case FTRACE_BUG_CALL: + pr_info("Setting ftrace call site to call ftrace function\n"); + break; + case FTRACE_BUG_UPDATE: + pr_info("Updating ftrace call site to call a different ftrace function\n"); + break; + } } /** * ftrace_bug - report and shutdown function tracer * @failed: The failed type (EFAULT, EINVAL, EPERM) - * @ip: The address that failed + * @rec: The record that failed * * The arch code that enables or disables the function tracing * can call ftrace_bug() when it has detected a problem in * modifying the code. @failed should be one of either: * EFAULT - if the problem happens on reading the @ip address * EINVAL - if what is read at @ip is not what was expected - * EPERM - if the problem happens on writting to the @ip address + * EPERM - if the problem happens on writing to the @ip address */ -void ftrace_bug(int failed, unsigned long ip) +void ftrace_bug(int failed, struct dyn_ftrace *rec) { + unsigned long ip = rec ? rec->ip : 0; + + pr_info("------------[ ftrace bug ]------------\n"); + switch (failed) { case -EFAULT: - FTRACE_WARN_ON_ONCE(1); pr_info("ftrace faulted on modifying "); - print_ip_sym(ip); + print_ip_sym(KERN_INFO, ip); break; case -EINVAL: - FTRACE_WARN_ON_ONCE(1); pr_info("ftrace failed to modify "); - print_ip_sym(ip); - print_ip_ins(" actual: ", (unsigned char *)ip); - printk(KERN_CONT "\n"); + print_ip_sym(KERN_INFO, ip); + print_ip_ins(" actual: ", (unsigned char *)ip); + pr_cont("\n"); + if (ftrace_expected) { + print_ip_ins(" expected: ", ftrace_expected); + pr_cont("\n"); + } break; case -EPERM: - FTRACE_WARN_ON_ONCE(1); pr_info("ftrace faulted on writing "); - print_ip_sym(ip); + print_ip_sym(KERN_INFO, ip); break; default: - FTRACE_WARN_ON_ONCE(1); pr_info("ftrace faulted on unknown error "); - print_ip_sym(ip); + print_ip_sym(KERN_INFO, ip); + } + print_bug_type(); + if (rec) { + struct ftrace_ops *ops = NULL; + + pr_info("ftrace record flags: %lx\n", rec->flags); + pr_cont(" (%ld)%s%s", ftrace_rec_count(rec), + rec->flags & FTRACE_FL_REGS ? " R" : " ", + rec->flags & FTRACE_FL_CALL_OPS ? " O" : " "); + if (rec->flags & FTRACE_FL_TRAMP_EN) { + ops = ftrace_find_tramp_ops_any(rec); + if (ops) { + do { + pr_cont("\ttramp: %pS (%pS)", + (void *)ops->trampoline, + (void *)ops->func); + ops = ftrace_find_tramp_ops_next(rec, ops); + } while (ops); + } else + pr_cont("\ttramp: ERROR!"); + + } + ip = ftrace_get_addr_curr(rec); + pr_cont("\n expected tramp: %lx\n", ip); } + + FTRACE_WARN_ON_ONCE(1); } -static int ftrace_check_record(struct dyn_ftrace *rec, int enable, int update) +static int ftrace_check_record(struct dyn_ftrace *rec, bool enable, bool update) { unsigned long flag = 0UL; + ftrace_bug_type = FTRACE_BUG_UNKNOWN; + + if (skip_record(rec)) + return FTRACE_UPDATE_IGNORE; + /* * If we are updating calls: * @@ -1714,17 +2268,56 @@ static int ftrace_check_record(struct dyn_ftrace *rec, int enable, int update) * If we are disabling calls, then disable all records that * are enabled. */ - if (enable && (rec->flags & ~FTRACE_FL_MASK)) + if (enable && ftrace_rec_count(rec)) flag = FTRACE_FL_ENABLED; /* - * If enabling and the REGS flag does not match the REGS_EN, then - * do not ignore this record. Set flags to fail the compare against - * ENABLED. + * If enabling and the REGS flag does not match the REGS_EN, or + * the TRAMP flag doesn't match the TRAMP_EN, then do not ignore + * this record. Set flags to fail the compare against ENABLED. + * Same for direct calls. */ - if (flag && - (!(rec->flags & FTRACE_FL_REGS) != !(rec->flags & FTRACE_FL_REGS_EN))) - flag |= FTRACE_FL_REGS; + if (flag) { + if (!(rec->flags & FTRACE_FL_REGS) != + !(rec->flags & FTRACE_FL_REGS_EN)) + flag |= FTRACE_FL_REGS; + + if (!(rec->flags & FTRACE_FL_TRAMP) != + !(rec->flags & FTRACE_FL_TRAMP_EN)) + flag |= FTRACE_FL_TRAMP; + + /* + * Direct calls are special, as count matters. + * We must test the record for direct, if the + * DIRECT and DIRECT_EN do not match, but only + * if the count is 1. That's because, if the + * count is something other than one, we do not + * want the direct enabled (it will be done via the + * direct helper). But if DIRECT_EN is set, and + * the count is not one, we need to clear it. + * + */ + if (ftrace_rec_count(rec) == 1) { + if (!(rec->flags & FTRACE_FL_DIRECT) != + !(rec->flags & FTRACE_FL_DIRECT_EN)) + flag |= FTRACE_FL_DIRECT; + } else if (rec->flags & FTRACE_FL_DIRECT_EN) { + flag |= FTRACE_FL_DIRECT; + } + + /* + * Ops calls are special, as count matters. + * As with direct calls, they must only be enabled when count + * is one, otherwise they'll be handled via the list ops. + */ + if (ftrace_rec_count(rec) == 1) { + if (!(rec->flags & FTRACE_FL_CALL_OPS) != + !(rec->flags & FTRACE_FL_CALL_OPS_EN)) + flag |= FTRACE_FL_CALL_OPS; + } else if (rec->flags & FTRACE_FL_CALL_OPS_EN) { + flag |= FTRACE_FL_CALL_OPS; + } + } /* If the state of this record hasn't changed, then do nothing */ if ((rec->flags & FTRACE_FL_ENABLED) == flag) @@ -1735,125 +2328,454 @@ static int ftrace_check_record(struct dyn_ftrace *rec, int enable, int update) flag ^= rec->flags & FTRACE_FL_ENABLED; if (update) { - rec->flags |= FTRACE_FL_ENABLED; + rec->flags |= FTRACE_FL_ENABLED | FTRACE_FL_TOUCHED; if (flag & FTRACE_FL_REGS) { if (rec->flags & FTRACE_FL_REGS) rec->flags |= FTRACE_FL_REGS_EN; else rec->flags &= ~FTRACE_FL_REGS_EN; } + if (flag & FTRACE_FL_TRAMP) { + if (rec->flags & FTRACE_FL_TRAMP) + rec->flags |= FTRACE_FL_TRAMP_EN; + else + rec->flags &= ~FTRACE_FL_TRAMP_EN; + } + + /* Keep track of anything that modifies the function */ + if (rec->flags & (FTRACE_FL_DIRECT | FTRACE_FL_IPMODIFY)) + rec->flags |= FTRACE_FL_MODIFIED; + + if (flag & FTRACE_FL_DIRECT) { + /* + * If there's only one user (direct_ops helper) + * then we can call the direct function + * directly (no ftrace trampoline). + */ + if (ftrace_rec_count(rec) == 1) { + if (rec->flags & FTRACE_FL_DIRECT) + rec->flags |= FTRACE_FL_DIRECT_EN; + else + rec->flags &= ~FTRACE_FL_DIRECT_EN; + } else { + /* + * Can only call directly if there's + * only one callback to the function. + */ + rec->flags &= ~FTRACE_FL_DIRECT_EN; + } + } + + if (flag & FTRACE_FL_CALL_OPS) { + if (ftrace_rec_count(rec) == 1) { + if (rec->flags & FTRACE_FL_CALL_OPS) + rec->flags |= FTRACE_FL_CALL_OPS_EN; + else + rec->flags &= ~FTRACE_FL_CALL_OPS_EN; + } else { + /* + * Can only call directly if there's + * only one set of associated ops. + */ + rec->flags &= ~FTRACE_FL_CALL_OPS_EN; + } + } } /* * If this record is being updated from a nop, then * return UPDATE_MAKE_CALL. - * Otherwise, if the EN flag is set, then return - * UPDATE_MODIFY_CALL_REGS to tell the caller to convert - * from the non-save regs, to a save regs function. * Otherwise, * return UPDATE_MODIFY_CALL to tell the caller to convert - * from the save regs, to a non-save regs function. + * from the save regs, to a non-save regs function or + * vice versa, or from a trampoline call. */ - if (flag & FTRACE_FL_ENABLED) + if (flag & FTRACE_FL_ENABLED) { + ftrace_bug_type = FTRACE_BUG_CALL; return FTRACE_UPDATE_MAKE_CALL; - else if (rec->flags & FTRACE_FL_REGS_EN) - return FTRACE_UPDATE_MODIFY_CALL_REGS; - else - return FTRACE_UPDATE_MODIFY_CALL; + } + + ftrace_bug_type = FTRACE_BUG_UPDATE; + return FTRACE_UPDATE_MODIFY_CALL; } if (update) { /* If there's no more users, clear all flags */ - if (!(rec->flags & ~FTRACE_FL_MASK)) - rec->flags = 0; + if (!ftrace_rec_count(rec)) + rec->flags &= FTRACE_NOCLEAR_FLAGS; else - /* Just disable the record (keep REGS state) */ - rec->flags &= ~FTRACE_FL_ENABLED; + /* + * Just disable the record, but keep the ops TRAMP + * and REGS states. The _EN flags must be disabled though. + */ + rec->flags &= ~(FTRACE_FL_ENABLED | FTRACE_FL_TRAMP_EN | + FTRACE_FL_REGS_EN | FTRACE_FL_DIRECT_EN | + FTRACE_FL_CALL_OPS_EN); } + ftrace_bug_type = FTRACE_BUG_NOP; return FTRACE_UPDATE_MAKE_NOP; } /** - * ftrace_update_record, set a record that now is tracing or not + * ftrace_update_record - set a record that now is tracing or not * @rec: the record to update - * @enable: set to 1 if the record is tracing, zero to force disable + * @enable: set to true if the record is tracing, false to force disable * * The records that represent all functions that can be traced need * to be updated when tracing has been enabled. */ -int ftrace_update_record(struct dyn_ftrace *rec, int enable) +int ftrace_update_record(struct dyn_ftrace *rec, bool enable) { - return ftrace_check_record(rec, enable, 1); + return ftrace_check_record(rec, enable, true); } /** - * ftrace_test_record, check if the record has been enabled or not + * ftrace_test_record - check if the record has been enabled or not * @rec: the record to test - * @enable: set to 1 to check if enabled, 0 if it is disabled + * @enable: set to true to check if enabled, false if it is disabled * * The arch code may need to test if a record is already set to * tracing to determine how to modify the function code that it * represents. */ -int ftrace_test_record(struct dyn_ftrace *rec, int enable) +int ftrace_test_record(struct dyn_ftrace *rec, bool enable) +{ + return ftrace_check_record(rec, enable, false); +} + +static struct ftrace_ops * +ftrace_find_tramp_ops_any(struct dyn_ftrace *rec) +{ + struct ftrace_ops *op; + unsigned long ip = rec->ip; + + do_for_each_ftrace_op(op, ftrace_ops_list) { + + if (!op->trampoline) + continue; + + if (hash_contains_ip(ip, op->func_hash)) + return op; + } while_for_each_ftrace_op(op); + + return NULL; +} + +static struct ftrace_ops * +ftrace_find_tramp_ops_any_other(struct dyn_ftrace *rec, struct ftrace_ops *op_exclude) +{ + struct ftrace_ops *op; + unsigned long ip = rec->ip; + + do_for_each_ftrace_op(op, ftrace_ops_list) { + + if (op == op_exclude || !op->trampoline) + continue; + + if (hash_contains_ip(ip, op->func_hash)) + return op; + } while_for_each_ftrace_op(op); + + return NULL; +} + +static struct ftrace_ops * +ftrace_find_tramp_ops_next(struct dyn_ftrace *rec, + struct ftrace_ops *op) +{ + unsigned long ip = rec->ip; + + while_for_each_ftrace_op(op) { + + if (!op->trampoline) + continue; + + if (hash_contains_ip(ip, op->func_hash)) + return op; + } + + return NULL; +} + +static struct ftrace_ops * +ftrace_find_tramp_ops_curr(struct dyn_ftrace *rec) +{ + struct ftrace_ops *op; + unsigned long ip = rec->ip; + + /* + * Need to check removed ops first. + * If they are being removed, and this rec has a tramp, + * and this rec is in the ops list, then it would be the + * one with the tramp. + */ + if (removed_ops) { + if (hash_contains_ip(ip, &removed_ops->old_hash)) + return removed_ops; + } + + /* + * Need to find the current trampoline for a rec. + * Now, a trampoline is only attached to a rec if there + * was a single 'ops' attached to it. But this can be called + * when we are adding another op to the rec or removing the + * current one. Thus, if the op is being added, we can + * ignore it because it hasn't attached itself to the rec + * yet. + * + * If an ops is being modified (hooking to different functions) + * then we don't care about the new functions that are being + * added, just the old ones (that are probably being removed). + * + * If we are adding an ops to a function that already is using + * a trampoline, it needs to be removed (trampolines are only + * for single ops connected), then an ops that is not being + * modified also needs to be checked. + */ + do_for_each_ftrace_op(op, ftrace_ops_list) { + + if (!op->trampoline) + continue; + + /* + * If the ops is being added, it hasn't gotten to + * the point to be removed from this tree yet. + */ + if (op->flags & FTRACE_OPS_FL_ADDING) + continue; + + + /* + * If the ops is being modified and is in the old + * hash, then it is probably being removed from this + * function. + */ + if ((op->flags & FTRACE_OPS_FL_MODIFYING) && + hash_contains_ip(ip, &op->old_hash)) + return op; + /* + * If the ops is not being added or modified, and it's + * in its normal filter hash, then this must be the one + * we want! + */ + if (!(op->flags & FTRACE_OPS_FL_MODIFYING) && + hash_contains_ip(ip, op->func_hash)) + return op; + + } while_for_each_ftrace_op(op); + + return NULL; +} + +static struct ftrace_ops * +ftrace_find_tramp_ops_new(struct dyn_ftrace *rec) +{ + struct ftrace_ops *op; + unsigned long ip = rec->ip; + + do_for_each_ftrace_op(op, ftrace_ops_list) { + /* pass rec in as regs to have non-NULL val */ + if (hash_contains_ip(ip, op->func_hash)) + return op; + } while_for_each_ftrace_op(op); + + return NULL; +} + +struct ftrace_ops * +ftrace_find_unique_ops(struct dyn_ftrace *rec) +{ + struct ftrace_ops *op, *found = NULL; + unsigned long ip = rec->ip; + + do_for_each_ftrace_op(op, ftrace_ops_list) { + + if (hash_contains_ip(ip, op->func_hash)) { + if (found) + return NULL; + found = op; + } + + } while_for_each_ftrace_op(op); + + return found; +} + +#ifdef CONFIG_DYNAMIC_FTRACE_WITH_DIRECT_CALLS +/* Protected by rcu_tasks for reading, and direct_mutex for writing */ +static struct ftrace_hash __rcu *direct_functions = EMPTY_HASH; +static DEFINE_MUTEX(direct_mutex); + +/* + * Search the direct_functions hash to see if the given instruction pointer + * has a direct caller attached to it. + */ +unsigned long ftrace_find_rec_direct(unsigned long ip) +{ + struct ftrace_func_entry *entry; + + entry = __ftrace_lookup_ip(direct_functions, ip); + if (!entry) + return 0; + + return entry->direct; +} + +static void call_direct_funcs(unsigned long ip, unsigned long pip, + struct ftrace_ops *ops, struct ftrace_regs *fregs) +{ + unsigned long addr = READ_ONCE(ops->direct_call); + + if (!addr) + return; + + arch_ftrace_set_direct_caller(fregs, addr); +} +#endif /* CONFIG_DYNAMIC_FTRACE_WITH_DIRECT_CALLS */ + +/** + * ftrace_get_addr_new - Get the call address to set to + * @rec: The ftrace record descriptor + * + * If the record has the FTRACE_FL_REGS set, that means that it + * wants to convert to a callback that saves all regs. If FTRACE_FL_REGS + * is not set, then it wants to convert to the normal callback. + * + * Returns: the address of the trampoline to set to + */ +unsigned long ftrace_get_addr_new(struct dyn_ftrace *rec) +{ + struct ftrace_ops *ops; + unsigned long addr; + + if ((rec->flags & FTRACE_FL_DIRECT) && + (ftrace_rec_count(rec) == 1)) { + addr = ftrace_find_rec_direct(rec->ip); + if (addr) + return addr; + WARN_ON_ONCE(1); + } + + /* Trampolines take precedence over regs */ + if (rec->flags & FTRACE_FL_TRAMP) { + ops = ftrace_find_tramp_ops_new(rec); + if (FTRACE_WARN_ON(!ops || !ops->trampoline)) { + pr_warn("Bad trampoline accounting at: %p (%pS) (%lx)\n", + (void *)rec->ip, (void *)rec->ip, rec->flags); + /* Ftrace is shutting down, return anything */ + return (unsigned long)FTRACE_ADDR; + } + return ops->trampoline; + } + + if (rec->flags & FTRACE_FL_REGS) + return (unsigned long)FTRACE_REGS_ADDR; + else + return (unsigned long)FTRACE_ADDR; +} + +/** + * ftrace_get_addr_curr - Get the call address that is already there + * @rec: The ftrace record descriptor + * + * The FTRACE_FL_REGS_EN is set when the record already points to + * a function that saves all the regs. Basically the '_EN' version + * represents the current state of the function. + * + * Returns: the address of the trampoline that is currently being called + */ +unsigned long ftrace_get_addr_curr(struct dyn_ftrace *rec) { - return ftrace_check_record(rec, enable, 0); + struct ftrace_ops *ops; + unsigned long addr; + + /* Direct calls take precedence over trampolines */ + if (rec->flags & FTRACE_FL_DIRECT_EN) { + addr = ftrace_find_rec_direct(rec->ip); + if (addr) + return addr; + WARN_ON_ONCE(1); + } + + /* Trampolines take precedence over regs */ + if (rec->flags & FTRACE_FL_TRAMP_EN) { + ops = ftrace_find_tramp_ops_curr(rec); + if (FTRACE_WARN_ON(!ops)) { + pr_warn("Bad trampoline accounting at: %p (%pS)\n", + (void *)rec->ip, (void *)rec->ip); + /* Ftrace is shutting down, return anything */ + return (unsigned long)FTRACE_ADDR; + } + return ops->trampoline; + } + + if (rec->flags & FTRACE_FL_REGS_EN) + return (unsigned long)FTRACE_REGS_ADDR; + else + return (unsigned long)FTRACE_ADDR; } static int -__ftrace_replace_code(struct dyn_ftrace *rec, int enable) +__ftrace_replace_code(struct dyn_ftrace *rec, bool enable) { unsigned long ftrace_old_addr; unsigned long ftrace_addr; int ret; + ftrace_addr = ftrace_get_addr_new(rec); + + /* This needs to be done before we call ftrace_update_record */ + ftrace_old_addr = ftrace_get_addr_curr(rec); + ret = ftrace_update_record(rec, enable); - if (rec->flags & FTRACE_FL_REGS) - ftrace_addr = (unsigned long)FTRACE_REGS_ADDR; - else - ftrace_addr = (unsigned long)FTRACE_ADDR; + ftrace_bug_type = FTRACE_BUG_UNKNOWN; switch (ret) { case FTRACE_UPDATE_IGNORE: return 0; case FTRACE_UPDATE_MAKE_CALL: + ftrace_bug_type = FTRACE_BUG_CALL; return ftrace_make_call(rec, ftrace_addr); case FTRACE_UPDATE_MAKE_NOP: - return ftrace_make_nop(NULL, rec, ftrace_addr); + ftrace_bug_type = FTRACE_BUG_NOP; + return ftrace_make_nop(NULL, rec, ftrace_old_addr); - case FTRACE_UPDATE_MODIFY_CALL_REGS: case FTRACE_UPDATE_MODIFY_CALL: - if (rec->flags & FTRACE_FL_REGS) - ftrace_old_addr = (unsigned long)FTRACE_ADDR; - else - ftrace_old_addr = (unsigned long)FTRACE_REGS_ADDR; - + ftrace_bug_type = FTRACE_BUG_UPDATE; return ftrace_modify_call(rec, ftrace_old_addr, ftrace_addr); } - return -1; /* unknow ftrace bug */ + return -1; /* unknown ftrace bug */ } -void __weak ftrace_replace_code(int enable) +void __weak ftrace_replace_code(int mod_flags) { struct dyn_ftrace *rec; struct ftrace_page *pg; + bool enable = mod_flags & FTRACE_MODIFY_ENABLE_FL; + int schedulable = mod_flags & FTRACE_MODIFY_MAY_SLEEP_FL; int failed; if (unlikely(ftrace_disabled)) return; do_for_each_ftrace_rec(pg, rec) { + + if (skip_record(rec)) + continue; + failed = __ftrace_replace_code(rec, enable); if (failed) { - ftrace_bug(failed, rec->ip); + ftrace_bug(failed, rec); /* Stop processing */ return; } + if (schedulable) + cond_resched(); } while_for_each_ftrace_rec(); } @@ -1863,9 +2785,9 @@ struct ftrace_rec_iter { }; /** - * ftrace_rec_iter_start, start up iterating over traced functions + * ftrace_rec_iter_start - start up iterating over traced functions * - * Returns an iterator handle that is used to iterate over all + * Returns: an iterator handle that is used to iterate over all * the records that represent address locations where functions * are traced. * @@ -1894,10 +2816,10 @@ struct ftrace_rec_iter *ftrace_rec_iter_start(void) } /** - * ftrace_rec_iter_next, get the next record to process. + * ftrace_rec_iter_next - get the next record to process. * @iter: The handle to the iterator. * - * Returns the next iterator after the given iterator @iter. + * Returns: the next iterator after the given iterator @iter. */ struct ftrace_rec_iter *ftrace_rec_iter_next(struct ftrace_rec_iter *iter) { @@ -1919,10 +2841,10 @@ struct ftrace_rec_iter *ftrace_rec_iter_next(struct ftrace_rec_iter *iter) } /** - * ftrace_rec_iter_record, get the record at the iterator location + * ftrace_rec_iter_record - get the record at the iterator location * @iter: The current iterator location * - * Returns the record that the current @iter is at. + * Returns: the record that the current @iter is at. */ struct dyn_ftrace *ftrace_rec_iter_record(struct ftrace_rec_iter *iter) { @@ -1930,19 +2852,17 @@ struct dyn_ftrace *ftrace_rec_iter_record(struct ftrace_rec_iter *iter) } static int -ftrace_code_disable(struct module *mod, struct dyn_ftrace *rec) +ftrace_nop_initialize(struct module *mod, struct dyn_ftrace *rec) { - unsigned long ip; int ret; - ip = rec->ip; - if (unlikely(ftrace_disabled)) return 0; - ret = ftrace_make_nop(mod, rec, MCOUNT_ADDR); + ret = ftrace_init_nop(mod, rec); if (ret) { - ftrace_bug(ret, ip); + ftrace_bug_type = FTRACE_BUG_INIT; + ftrace_bug(ret, rec); return 0; } return 1; @@ -1952,34 +2872,77 @@ ftrace_code_disable(struct module *mod, struct dyn_ftrace *rec) * archs can override this function if they must do something * before the modifying code is performed. */ -int __weak ftrace_arch_code_modify_prepare(void) +void __weak ftrace_arch_code_modify_prepare(void) { - return 0; } /* * archs can override this function if they must do something * after the modifying code is performed. */ -int __weak ftrace_arch_code_modify_post_process(void) +void __weak ftrace_arch_code_modify_post_process(void) { - return 0; +} + +static int update_ftrace_func(ftrace_func_t func) +{ + static ftrace_func_t save_func; + + /* Avoid updating if it hasn't changed */ + if (func == save_func) + return 0; + + save_func = func; + + return ftrace_update_ftrace_func(func); } void ftrace_modify_all_code(int command) { + int update = command & FTRACE_UPDATE_TRACE_FUNC; + int mod_flags = 0; + int err = 0; + + if (command & FTRACE_MAY_SLEEP) + mod_flags = FTRACE_MODIFY_MAY_SLEEP_FL; + + /* + * If the ftrace_caller calls a ftrace_ops func directly, + * we need to make sure that it only traces functions it + * expects to trace. When doing the switch of functions, + * we need to update to the ftrace_ops_list_func first + * before the transition between old and new calls are set, + * as the ftrace_ops_list_func will check the ops hashes + * to make sure the ops are having the right functions + * traced. + */ + if (update) { + err = update_ftrace_func(ftrace_ops_list_func); + if (FTRACE_WARN_ON(err)) + return; + } + if (command & FTRACE_UPDATE_CALLS) - ftrace_replace_code(1); + ftrace_replace_code(mod_flags | FTRACE_MODIFY_ENABLE_FL); else if (command & FTRACE_DISABLE_CALLS) - ftrace_replace_code(0); - - if (command & FTRACE_UPDATE_TRACE_FUNC) - ftrace_update_ftrace_func(ftrace_trace_function); + ftrace_replace_code(mod_flags); + + if (update && ftrace_trace_function != ftrace_ops_list_func) { + function_trace_op = set_function_trace_op; + smp_wmb(); + /* If irqs are disabled, we are in stop machine */ + if (!irqs_disabled()) + smp_call_function(ftrace_sync_ipi, NULL, 1); + err = update_ftrace_func(ftrace_trace_function); + if (FTRACE_WARN_ON(err)) + return; + } if (command & FTRACE_START_FUNC_RET) - ftrace_enable_ftrace_graph_caller(); + err = ftrace_enable_ftrace_graph_caller(); else if (command & FTRACE_STOP_FUNC_RET) - ftrace_disable_ftrace_graph_caller(); + err = ftrace_disable_ftrace_graph_caller(); + FTRACE_WARN_ON(err); } static int __ftrace_modify_code(void *data) @@ -1992,7 +2955,7 @@ static int __ftrace_modify_code(void *data) } /** - * ftrace_run_stop_machine, go back to the stop machine method + * ftrace_run_stop_machine - go back to the stop machine method * @command: The command to tell ftrace what to do * * If an arch needs to fall back to the stop machine method, the @@ -2004,7 +2967,7 @@ void ftrace_run_stop_machine(int command) } /** - * arch_ftrace_update_code, modify the code to trace or not trace + * arch_ftrace_update_code - modify the code to trace or not trace * @command: The command that needs to be done * * Archs can override this function if it does not need to @@ -2017,17 +2980,7 @@ void __weak arch_ftrace_update_code(int command) static void ftrace_run_update_code(int command) { - int ret; - - ret = ftrace_arch_code_modify_prepare(); - FTRACE_WARN_ON(ret); - if (ret) - return; - /* - * Do not call function tracer while we update the code. - * We are in stop machine. - */ - function_trace_stop++; + ftrace_arch_code_modify_prepare(); /* * By default we use stop_machine() to modify the code. @@ -2037,15 +2990,72 @@ static void ftrace_run_update_code(int command) */ arch_ftrace_update_code(command); - function_trace_stop--; + ftrace_arch_code_modify_post_process(); +} - ret = ftrace_arch_code_modify_post_process(); - FTRACE_WARN_ON(ret); +static void ftrace_run_modify_code(struct ftrace_ops *ops, int command, + struct ftrace_ops_hash *old_hash) +{ + ops->flags |= FTRACE_OPS_FL_MODIFYING; + ops->old_hash.filter_hash = old_hash->filter_hash; + ops->old_hash.notrace_hash = old_hash->notrace_hash; + ftrace_run_update_code(command); + ops->old_hash.filter_hash = NULL; + ops->old_hash.notrace_hash = NULL; + ops->flags &= ~FTRACE_OPS_FL_MODIFYING; } static ftrace_func_t saved_ftrace_func; static int ftrace_start_up; -static int global_start_up; + +void __weak arch_ftrace_trampoline_free(struct ftrace_ops *ops) +{ +} + +/* List of trace_ops that have allocated trampolines */ +static LIST_HEAD(ftrace_ops_trampoline_list); + +static void ftrace_add_trampoline_to_kallsyms(struct ftrace_ops *ops) +{ + lockdep_assert_held(&ftrace_lock); + list_add_rcu(&ops->list, &ftrace_ops_trampoline_list); +} + +static void ftrace_remove_trampoline_from_kallsyms(struct ftrace_ops *ops) +{ + lockdep_assert_held(&ftrace_lock); + list_del_rcu(&ops->list); + synchronize_rcu(); +} + +/* + * "__builtin__ftrace" is used as a module name in /proc/kallsyms for symbols + * for pages allocated for ftrace purposes, even though "__builtin__ftrace" is + * not a module. + */ +#define FTRACE_TRAMPOLINE_MOD "__builtin__ftrace" +#define FTRACE_TRAMPOLINE_SYM "ftrace_trampoline" + +static void ftrace_trampoline_free(struct ftrace_ops *ops) +{ + if (ops && (ops->flags & FTRACE_OPS_FL_ALLOC_TRAMP) && + ops->trampoline) { + /* + * Record the text poke event before the ksymbol unregister + * event. + */ + perf_event_text_poke((void *)ops->trampoline, + (void *)ops->trampoline, + ops->trampoline_size, NULL, 0); + perf_event_ksymbol(PERF_RECORD_KSYMBOL_TYPE_OOL, + ops->trampoline, ops->trampoline_size, + true, FTRACE_TRAMPOLINE_SYM); + /* Remove from kallsyms after the perf events */ + ftrace_remove_trampoline_from_kallsyms(ops); + } + + arch_ftrace_trampoline_free(ops); +} static void ftrace_startup_enable(int command) { @@ -2060,40 +3070,77 @@ static void ftrace_startup_enable(int command) ftrace_run_update_code(command); } -static int ftrace_startup(struct ftrace_ops *ops, int command) +static void ftrace_startup_all(int command) +{ + update_all_ops = true; + ftrace_startup_enable(command); + update_all_ops = false; +} + +int ftrace_startup(struct ftrace_ops *ops, int command) { - bool hash_enable = true; + int ret; if (unlikely(ftrace_disabled)) return -ENODEV; + ret = __register_ftrace_function(ops); + if (ret) + return ret; + ftrace_start_up++; - command |= FTRACE_UPDATE_CALLS; - /* ops marked global share the filter hashes */ - if (ops->flags & FTRACE_OPS_FL_GLOBAL) { - ops = &global_ops; - /* Don't update hash if global is already set */ - if (global_start_up) - hash_enable = false; - global_start_up++; + /* + * Note that ftrace probes uses this to start up + * and modify functions it will probe. But we still + * set the ADDING flag for modification, as probes + * do not have trampolines. If they add them in the + * future, then the probes will need to distinguish + * between adding and updating probes. + */ + ops->flags |= FTRACE_OPS_FL_ENABLED | FTRACE_OPS_FL_ADDING; + + ret = ftrace_hash_ipmodify_enable(ops); + if (ret < 0) { + /* Rollback registration process */ + __unregister_ftrace_function(ops); + ftrace_start_up--; + ops->flags &= ~FTRACE_OPS_FL_ENABLED; + if (ops->flags & FTRACE_OPS_FL_DYNAMIC) + ftrace_trampoline_free(ops); + return ret; } - ops->flags |= FTRACE_OPS_FL_ENABLED; - if (hash_enable) - ftrace_hash_rec_enable(ops, 1); + if (ftrace_hash_rec_enable(ops)) + command |= FTRACE_UPDATE_CALLS; ftrace_startup_enable(command); + /* + * If ftrace is in an undefined state, we just remove ops from list + * to prevent the NULL pointer, instead of totally rolling it back and + * free trampoline, because those actions could cause further damage. + */ + if (unlikely(ftrace_disabled)) { + __unregister_ftrace_function(ops); + return -ENODEV; + } + + ops->flags &= ~FTRACE_OPS_FL_ADDING; + return 0; } -static void ftrace_shutdown(struct ftrace_ops *ops, int command) +int ftrace_shutdown(struct ftrace_ops *ops, int command) { - bool hash_disable = true; + int ret; if (unlikely(ftrace_disabled)) - return; + return -ENODEV; + + ret = __unregister_ftrace_function(ops); + if (ret) + return ret; ftrace_start_up--; /* @@ -2103,24 +3150,13 @@ static void ftrace_shutdown(struct ftrace_ops *ops, int command) */ WARN_ON_ONCE(ftrace_start_up < 0); - if (ops->flags & FTRACE_OPS_FL_GLOBAL) { - ops = &global_ops; - global_start_up--; - WARN_ON_ONCE(global_start_up < 0); - /* Don't update hash if global still has users */ - if (global_start_up) { - WARN_ON_ONCE(!ftrace_start_up); - hash_disable = false; - } - } - - if (hash_disable) - ftrace_hash_rec_disable(ops, 1); + /* Disabling ipmodify never fails */ + ftrace_hash_ipmodify_disable(ops); - if (ops != &global_ops || !global_start_up) - ops->flags &= ~FTRACE_OPS_FL_ENABLED; + if (ftrace_hash_rec_disable(ops)) + command |= FTRACE_UPDATE_CALLS; - command |= FTRACE_UPDATE_CALLS; + ops->flags &= ~FTRACE_OPS_FL_ENABLED; if (saved_ftrace_func != ftrace_trace_function) { saved_ftrace_func = ftrace_trace_function; @@ -2128,114 +3164,672 @@ static void ftrace_shutdown(struct ftrace_ops *ops, int command) } if (!command || !ftrace_enabled) - return; + goto out; + + /* + * If the ops uses a trampoline, then it needs to be + * tested first on update. + */ + ops->flags |= FTRACE_OPS_FL_REMOVING; + removed_ops = ops; + + /* The trampoline logic checks the old hashes */ + ops->old_hash.filter_hash = ops->func_hash->filter_hash; + ops->old_hash.notrace_hash = ops->func_hash->notrace_hash; ftrace_run_update_code(command); + + /* + * If there's no more ops registered with ftrace, run a + * sanity check to make sure all rec flags are cleared. + */ + if (rcu_dereference_protected(ftrace_ops_list, + lockdep_is_held(&ftrace_lock)) == &ftrace_list_end) { + struct ftrace_page *pg; + struct dyn_ftrace *rec; + + do_for_each_ftrace_rec(pg, rec) { + if (FTRACE_WARN_ON_ONCE(rec->flags & ~FTRACE_NOCLEAR_FLAGS)) + pr_warn(" %pS flags:%lx\n", + (void *)rec->ip, rec->flags); + } while_for_each_ftrace_rec(); + } + + ops->old_hash.filter_hash = NULL; + ops->old_hash.notrace_hash = NULL; + + removed_ops = NULL; + ops->flags &= ~FTRACE_OPS_FL_REMOVING; + +out: + /* + * Dynamic ops may be freed, we must make sure that all + * callers are done before leaving this function. + */ + if (ops->flags & FTRACE_OPS_FL_DYNAMIC) { + /* + * We need to do a hard force of sched synchronization. + * This is because we use preempt_disable() to do RCU, but + * the function tracers can be called where RCU is not watching + * (like before user_exit()). We can not rely on the RCU + * infrastructure to do the synchronization, thus we must do it + * ourselves. + */ + synchronize_rcu_tasks_rude(); + + /* + * When the kernel is preemptive, tasks can be preempted + * while on a ftrace trampoline. Just scheduling a task on + * a CPU is not good enough to flush them. Calling + * synchronize_rcu_tasks() will wait for those tasks to + * execute and either schedule voluntarily or enter user space. + */ + synchronize_rcu_tasks(); + + ftrace_trampoline_free(ops); + } + + return 0; } -static void ftrace_startup_sysctl(void) +/* Simply make a copy of @src and return it */ +static struct ftrace_hash *copy_hash(struct ftrace_hash *src) { - if (unlikely(ftrace_disabled)) - return; + if (ftrace_hash_empty(src)) + return EMPTY_HASH; - /* Force update next time */ - saved_ftrace_func = NULL; - /* ftrace_start_up is true if we want ftrace running */ - if (ftrace_start_up) - ftrace_run_update_code(FTRACE_UPDATE_CALLS); + return alloc_and_copy_ftrace_hash(src->size_bits, src); } -static void ftrace_shutdown_sysctl(void) +/* + * Append @new_hash entries to @hash: + * + * If @hash is the EMPTY_HASH then it traces all functions and nothing + * needs to be done. + * + * If @new_hash is the EMPTY_HASH, then make *hash the EMPTY_HASH so + * that it traces everything. + * + * Otherwise, go through all of @new_hash and add anything that @hash + * doesn't already have, to @hash. + * + * The filter_hash updates uses just the append_hash() function + * and the notrace_hash does not. + */ +static int append_hash(struct ftrace_hash **hash, struct ftrace_hash *new_hash, + int size_bits) { - if (unlikely(ftrace_disabled)) - return; + struct ftrace_func_entry *entry; + int size; + int i; - /* ftrace_start_up is true if ftrace is running */ - if (ftrace_start_up) - ftrace_run_update_code(FTRACE_DISABLE_CALLS); + if (*hash) { + /* An empty hash does everything */ + if (ftrace_hash_empty(*hash)) + return 0; + } else { + *hash = alloc_ftrace_hash(size_bits); + if (!*hash) + return -ENOMEM; + } + + /* If new_hash has everything make hash have everything */ + if (ftrace_hash_empty(new_hash)) { + free_ftrace_hash(*hash); + *hash = EMPTY_HASH; + return 0; + } + + size = 1 << new_hash->size_bits; + for (i = 0; i < size; i++) { + hlist_for_each_entry(entry, &new_hash->buckets[i], hlist) { + /* Only add if not already in hash */ + if (!__ftrace_lookup_ip(*hash, entry->ip) && + add_hash_entry(*hash, entry->ip) == NULL) + return -ENOMEM; + } + } + return 0; } -static cycle_t ftrace_update_time; -static unsigned long ftrace_update_cnt; -unsigned long ftrace_update_tot_cnt; +/* + * Remove functions from @hash that are in @notrace_hash + */ +static void remove_hash(struct ftrace_hash *hash, struct ftrace_hash *notrace_hash) +{ + struct ftrace_func_entry *entry; + struct hlist_node *tmp; + int size; + int i; + + /* If the notrace hash is empty, there's nothing to do */ + if (ftrace_hash_empty(notrace_hash)) + return; + + size = 1 << hash->size_bits; + for (i = 0; i < size; i++) { + hlist_for_each_entry_safe(entry, tmp, &hash->buckets[i], hlist) { + if (!__ftrace_lookup_ip(notrace_hash, entry->ip)) + continue; + remove_hash_entry(hash, entry); + kfree(entry); + } + } +} -static int ops_traces_mod(struct ftrace_ops *ops) +/* + * Add to @hash only those that are in both @new_hash1 and @new_hash2 + * + * The notrace_hash updates uses just the intersect_hash() function + * and the filter_hash does not. + */ +static int intersect_hash(struct ftrace_hash **hash, struct ftrace_hash *new_hash1, + struct ftrace_hash *new_hash2) { - struct ftrace_hash *hash; + struct ftrace_func_entry *entry; + int size; + int i; + + /* + * If new_hash1 or new_hash2 is the EMPTY_HASH then make the hash + * empty as well as empty for notrace means none are notraced. + */ + if (ftrace_hash_empty(new_hash1) || ftrace_hash_empty(new_hash2)) { + free_ftrace_hash(*hash); + *hash = EMPTY_HASH; + return 0; + } - hash = ops->filter_hash; - return ftrace_hash_empty(hash); + size = 1 << new_hash1->size_bits; + for (i = 0; i < size; i++) { + hlist_for_each_entry(entry, &new_hash1->buckets[i], hlist) { + /* Only add if in both @new_hash1 and @new_hash2 */ + if (__ftrace_lookup_ip(new_hash2, entry->ip) && + add_hash_entry(*hash, entry->ip) == NULL) + return -ENOMEM; + } + } + /* If nothing intersects, make it the empty set */ + if (ftrace_hash_empty(*hash)) { + free_ftrace_hash(*hash); + *hash = EMPTY_HASH; + } + return 0; } -static int ftrace_update_code(struct module *mod) +static bool ops_equal(struct ftrace_hash *A, struct ftrace_hash *B) { - struct ftrace_page *pg; - struct dyn_ftrace *p; - cycle_t start, stop; - unsigned long ref = 0; + struct ftrace_func_entry *entry; + int size; int i; + if (ftrace_hash_empty(A)) + return ftrace_hash_empty(B); + + if (ftrace_hash_empty(B)) + return ftrace_hash_empty(A); + + if (A->count != B->count) + return false; + + size = 1 << A->size_bits; + for (i = 0; i < size; i++) { + hlist_for_each_entry(entry, &A->buckets[i], hlist) { + if (!__ftrace_lookup_ip(B, entry->ip)) + return false; + } + } + + return true; +} + +static void ftrace_ops_update_code(struct ftrace_ops *ops, + struct ftrace_ops_hash *old_hash); + +static int __ftrace_hash_move_and_update_ops(struct ftrace_ops *ops, + struct ftrace_hash **orig_hash, + struct ftrace_hash *hash, + int enable) +{ + struct ftrace_ops_hash old_hash_ops; + struct ftrace_hash *old_hash; + int ret; + + old_hash = *orig_hash; + old_hash_ops.filter_hash = ops->func_hash->filter_hash; + old_hash_ops.notrace_hash = ops->func_hash->notrace_hash; + ret = ftrace_hash_move(ops, enable, orig_hash, hash); + if (!ret) { + ftrace_ops_update_code(ops, &old_hash_ops); + free_ftrace_hash_rcu(old_hash); + } + return ret; +} + +static int ftrace_update_ops(struct ftrace_ops *ops, struct ftrace_hash *filter_hash, + struct ftrace_hash *notrace_hash) +{ + int ret; + + if (!ops_equal(filter_hash, ops->func_hash->filter_hash)) { + ret = __ftrace_hash_move_and_update_ops(ops, &ops->func_hash->filter_hash, + filter_hash, 1); + if (ret < 0) + return ret; + } + + if (!ops_equal(notrace_hash, ops->func_hash->notrace_hash)) { + ret = __ftrace_hash_move_and_update_ops(ops, &ops->func_hash->notrace_hash, + notrace_hash, 0); + if (ret < 0) + return ret; + } + + return 0; +} + +static int add_first_hash(struct ftrace_hash **filter_hash, struct ftrace_hash **notrace_hash, + struct ftrace_ops_hash *func_hash) +{ + /* If the filter hash is not empty, simply remove the nohash from it */ + if (!ftrace_hash_empty(func_hash->filter_hash)) { + *filter_hash = copy_hash(func_hash->filter_hash); + if (!*filter_hash) + return -ENOMEM; + remove_hash(*filter_hash, func_hash->notrace_hash); + *notrace_hash = EMPTY_HASH; + + } else { + *notrace_hash = copy_hash(func_hash->notrace_hash); + if (!*notrace_hash) + return -ENOMEM; + *filter_hash = EMPTY_HASH; + } + return 0; +} + +static int add_next_hash(struct ftrace_hash **filter_hash, struct ftrace_hash **notrace_hash, + struct ftrace_ops_hash *ops_hash, struct ftrace_ops_hash *subops_hash) +{ + int size_bits; + int ret; + + /* If the subops trace all functions so must the main ops */ + if (ftrace_hash_empty(ops_hash->filter_hash) || + ftrace_hash_empty(subops_hash->filter_hash)) { + *filter_hash = EMPTY_HASH; + } else { + /* + * The main ops filter hash is not empty, so its + * notrace_hash had better be, as the notrace hash + * is only used for empty main filter hashes. + */ + WARN_ON_ONCE(!ftrace_hash_empty(ops_hash->notrace_hash)); + + size_bits = max(ops_hash->filter_hash->size_bits, + subops_hash->filter_hash->size_bits); + + /* Copy the subops hash */ + *filter_hash = alloc_and_copy_ftrace_hash(size_bits, subops_hash->filter_hash); + if (!*filter_hash) + return -ENOMEM; + /* Remove any notrace functions from the copy */ + remove_hash(*filter_hash, subops_hash->notrace_hash); + + ret = append_hash(filter_hash, ops_hash->filter_hash, + size_bits); + if (ret < 0) { + free_ftrace_hash(*filter_hash); + *filter_hash = EMPTY_HASH; + return ret; + } + } + /* - * When adding a module, we need to check if tracers are - * currently enabled and if they are set to trace all functions. - * If they are, we need to enable the module functions as well - * as update the reference counts for those function records. + * Only process notrace hashes if the main filter hash is empty + * (tracing all functions), otherwise the filter hash will just + * remove the notrace hash functions, and the notrace hash is + * not needed. */ - if (mod) { - struct ftrace_ops *ops; + if (ftrace_hash_empty(*filter_hash)) { + /* + * Intersect the notrace functions. That is, if two + * subops are not tracing a set of functions, the + * main ops will only not trace the functions that are + * in both subops, but has to trace the functions that + * are only notrace in one of the subops, for the other + * subops to be able to trace them. + */ + size_bits = max(ops_hash->notrace_hash->size_bits, + subops_hash->notrace_hash->size_bits); + *notrace_hash = alloc_ftrace_hash(size_bits); + if (!*notrace_hash) + return -ENOMEM; + + ret = intersect_hash(notrace_hash, ops_hash->notrace_hash, + subops_hash->notrace_hash); + if (ret < 0) { + free_ftrace_hash(*notrace_hash); + *notrace_hash = EMPTY_HASH; + return ret; + } + } + return 0; +} + +/** + * ftrace_startup_subops - enable tracing for subops of an ops + * @ops: Manager ops (used to pick all the functions of its subops) + * @subops: A new ops to add to @ops + * @command: Extra commands to use to enable tracing + * + * The @ops is a manager @ops that has the filter that includes all the functions + * that its list of subops are tracing. Adding a new @subops will add the + * functions of @subops to @ops. + */ +int ftrace_startup_subops(struct ftrace_ops *ops, struct ftrace_ops *subops, int command) +{ + struct ftrace_hash *filter_hash = EMPTY_HASH; + struct ftrace_hash *notrace_hash = EMPTY_HASH; + struct ftrace_hash *save_filter_hash; + struct ftrace_hash *save_notrace_hash; + int ret; + + if (unlikely(ftrace_disabled)) + return -ENODEV; + + ftrace_ops_init(ops); + ftrace_ops_init(subops); + + if (WARN_ON_ONCE(subops->flags & FTRACE_OPS_FL_ENABLED)) + return -EBUSY; + + /* Make everything canonical (Just in case!) */ + if (!ops->func_hash->filter_hash) + ops->func_hash->filter_hash = EMPTY_HASH; + if (!ops->func_hash->notrace_hash) + ops->func_hash->notrace_hash = EMPTY_HASH; + if (!subops->func_hash->filter_hash) + subops->func_hash->filter_hash = EMPTY_HASH; + if (!subops->func_hash->notrace_hash) + subops->func_hash->notrace_hash = EMPTY_HASH; + + /* For the first subops to ops just enable it normally */ + if (list_empty(&ops->subop_list)) { + + /* The ops was empty, should have empty hashes */ + WARN_ON_ONCE(!ftrace_hash_empty(ops->func_hash->filter_hash)); + WARN_ON_ONCE(!ftrace_hash_empty(ops->func_hash->notrace_hash)); + + ret = add_first_hash(&filter_hash, ¬race_hash, subops->func_hash); + if (ret < 0) + return ret; + + save_filter_hash = ops->func_hash->filter_hash; + save_notrace_hash = ops->func_hash->notrace_hash; - for (ops = ftrace_ops_list; - ops != &ftrace_list_end; ops = ops->next) { - if (ops->flags & FTRACE_OPS_FL_ENABLED && - ops_traces_mod(ops)) - ref++; + ops->func_hash->filter_hash = filter_hash; + ops->func_hash->notrace_hash = notrace_hash; + list_add(&subops->list, &ops->subop_list); + ret = ftrace_startup(ops, command); + if (ret < 0) { + list_del(&subops->list); + ops->func_hash->filter_hash = save_filter_hash; + ops->func_hash->notrace_hash = save_notrace_hash; + free_ftrace_hash(filter_hash); + free_ftrace_hash(notrace_hash); + } else { + free_ftrace_hash(save_filter_hash); + free_ftrace_hash(save_notrace_hash); + subops->flags |= FTRACE_OPS_FL_ENABLED | FTRACE_OPS_FL_SUBOP; + subops->managed = ops; + } + return ret; + } + + /* + * Here there's already something attached. Here are the rules: + * If the new subops and main ops filter hashes are not empty: + * o Make a copy of the subops filter hash + * o Remove all functions in the nohash from it. + * o Add in the main hash filter functions + * o Remove any of these functions from the main notrace hash + */ + + ret = add_next_hash(&filter_hash, ¬race_hash, ops->func_hash, subops->func_hash); + if (ret < 0) + return ret; + + list_add(&subops->list, &ops->subop_list); + + ret = ftrace_update_ops(ops, filter_hash, notrace_hash); + free_ftrace_hash(filter_hash); + free_ftrace_hash(notrace_hash); + if (ret < 0) { + list_del(&subops->list); + } else { + subops->flags |= FTRACE_OPS_FL_ENABLED | FTRACE_OPS_FL_SUBOP; + subops->managed = ops; + } + return ret; +} + +static int rebuild_hashes(struct ftrace_hash **filter_hash, struct ftrace_hash **notrace_hash, + struct ftrace_ops *ops) +{ + struct ftrace_ops_hash temp_hash; + struct ftrace_ops *subops; + bool first = true; + int ret; + + temp_hash.filter_hash = EMPTY_HASH; + temp_hash.notrace_hash = EMPTY_HASH; + + list_for_each_entry(subops, &ops->subop_list, list) { + *filter_hash = EMPTY_HASH; + *notrace_hash = EMPTY_HASH; + + if (first) { + ret = add_first_hash(filter_hash, notrace_hash, subops->func_hash); + if (ret < 0) + return ret; + first = false; + } else { + ret = add_next_hash(filter_hash, notrace_hash, + &temp_hash, subops->func_hash); + if (ret < 0) { + free_ftrace_hash(temp_hash.filter_hash); + free_ftrace_hash(temp_hash.notrace_hash); + return ret; + } + } + + free_ftrace_hash(temp_hash.filter_hash); + free_ftrace_hash(temp_hash.notrace_hash); + + temp_hash.filter_hash = *filter_hash; + temp_hash.notrace_hash = *notrace_hash; + } + return 0; +} + +/** + * ftrace_shutdown_subops - Remove a subops from a manager ops + * @ops: A manager ops to remove @subops from + * @subops: The subops to remove from @ops + * @command: Any extra command flags to add to modifying the text + * + * Removes the functions being traced by the @subops from @ops. Note, it + * will not affect functions that are being traced by other subops that + * still exist in @ops. + * + * If the last subops is removed from @ops, then @ops is shutdown normally. + */ +int ftrace_shutdown_subops(struct ftrace_ops *ops, struct ftrace_ops *subops, int command) +{ + struct ftrace_hash *filter_hash = EMPTY_HASH; + struct ftrace_hash *notrace_hash = EMPTY_HASH; + int ret; + + if (unlikely(ftrace_disabled)) + return -ENODEV; + + if (WARN_ON_ONCE(!(subops->flags & FTRACE_OPS_FL_ENABLED))) + return -EINVAL; + + list_del(&subops->list); + + if (list_empty(&ops->subop_list)) { + /* Last one, just disable the current ops */ + + ret = ftrace_shutdown(ops, command); + if (ret < 0) { + list_add(&subops->list, &ops->subop_list); + return ret; } + + subops->flags &= ~FTRACE_OPS_FL_ENABLED; + + free_ftrace_hash(ops->func_hash->filter_hash); + free_ftrace_hash(ops->func_hash->notrace_hash); + ops->func_hash->filter_hash = EMPTY_HASH; + ops->func_hash->notrace_hash = EMPTY_HASH; + subops->flags &= ~(FTRACE_OPS_FL_ENABLED | FTRACE_OPS_FL_SUBOP); + subops->managed = NULL; + + return 0; + } + + /* Rebuild the hashes without subops */ + ret = rebuild_hashes(&filter_hash, ¬race_hash, ops); + if (ret < 0) + return ret; + + ret = ftrace_update_ops(ops, filter_hash, notrace_hash); + if (ret < 0) { + list_add(&subops->list, &ops->subop_list); + } else { + subops->flags &= ~(FTRACE_OPS_FL_ENABLED | FTRACE_OPS_FL_SUBOP); + subops->managed = NULL; + } + free_ftrace_hash(filter_hash); + free_ftrace_hash(notrace_hash); + return ret; +} + +static int ftrace_hash_move_and_update_subops(struct ftrace_ops *subops, + struct ftrace_hash **orig_subhash, + struct ftrace_hash *hash) +{ + struct ftrace_ops *ops = subops->managed; + struct ftrace_hash *notrace_hash; + struct ftrace_hash *filter_hash; + struct ftrace_hash *save_hash; + struct ftrace_hash *new_hash; + int ret; + + /* Manager ops can not be subops (yet) */ + if (WARN_ON_ONCE(!ops || ops->flags & FTRACE_OPS_FL_SUBOP)) + return -EINVAL; + + /* Move the new hash over to the subops hash */ + save_hash = *orig_subhash; + *orig_subhash = __ftrace_hash_move(hash); + if (!*orig_subhash) { + *orig_subhash = save_hash; + return -ENOMEM; + } + + ret = rebuild_hashes(&filter_hash, ¬race_hash, ops); + if (!ret) { + ret = ftrace_update_ops(ops, filter_hash, notrace_hash); + free_ftrace_hash(filter_hash); + free_ftrace_hash(notrace_hash); + } + + if (ret) { + /* Put back the original hash */ + new_hash = *orig_subhash; + *orig_subhash = save_hash; + free_ftrace_hash_rcu(new_hash); + } else { + free_ftrace_hash_rcu(save_hash); } + return ret; +} + + +u64 ftrace_update_time; +u64 ftrace_total_mod_time; +unsigned long ftrace_update_tot_cnt; +unsigned long ftrace_number_of_pages; +unsigned long ftrace_number_of_groups; + +static inline int ops_traces_mod(struct ftrace_ops *ops) +{ + /* + * Filter_hash being empty will default to trace module. + * But notrace hash requires a test of individual module functions. + */ + return ftrace_hash_empty(ops->func_hash->filter_hash) && + ftrace_hash_empty(ops->func_hash->notrace_hash); +} + +static int ftrace_update_code(struct module *mod, struct ftrace_page *new_pgs) +{ + bool init_nop = ftrace_need_init_nop(); + struct ftrace_page *pg; + struct dyn_ftrace *p; + u64 start, stop, update_time; + unsigned long update_cnt = 0; + unsigned long rec_flags = 0; + int i; start = ftrace_now(raw_smp_processor_id()); - ftrace_update_cnt = 0; - for (pg = ftrace_new_pgs; pg; pg = pg->next) { + /* + * When a module is loaded, this function is called to convert + * the calls to mcount in its text to nops, and also to create + * an entry in the ftrace data. Now, if ftrace is activated + * after this call, but before the module sets its text to + * read-only, the modification of enabling ftrace can fail if + * the read-only is done while ftrace is converting the calls. + * To prevent this, the module's records are set as disabled + * and will be enabled after the call to set the module's text + * to read-only. + */ + if (mod) + rec_flags |= FTRACE_FL_DISABLED; + + for (pg = new_pgs; pg; pg = pg->next) { for (i = 0; i < pg->index; i++) { + /* If something went wrong, bail without enabling anything */ if (unlikely(ftrace_disabled)) return -1; p = &pg->records[i]; - p->flags = ref; + p->flags = rec_flags; /* * Do the initial record conversion from mcount jump * to the NOP instructions. */ - if (!ftrace_code_disable(mod, p)) + if (init_nop && !ftrace_nop_initialize(mod, p)) break; - ftrace_update_cnt++; - - /* - * If the tracing is enabled, go ahead and enable the record. - * - * The reason not to enable the record immediatelly is the - * inherent check of ftrace_make_nop/ftrace_make_call for - * correct previous instructions. Making first the NOP - * conversion puts the module to the correct state, thus - * passing the ftrace_make_call check. - */ - if (ftrace_start_up && ref) { - int failed = __ftrace_replace_code(p, 1); - if (failed) - ftrace_bug(failed, p->ip); - } + update_cnt++; } } - ftrace_new_pgs = NULL; - stop = ftrace_now(raw_smp_processor_id()); - ftrace_update_time = stop - start; - ftrace_update_tot_cnt += ftrace_update_cnt; + update_time = stop - start; + if (mod) + ftrace_total_mod_time += update_time; + else + ftrace_update_time = update_time; + ftrace_update_tot_cnt += update_cnt; return 0; } @@ -2243,19 +3837,15 @@ static int ftrace_update_code(struct module *mod) static int ftrace_allocate_records(struct ftrace_page *pg, int count) { int order; + int pages; int cnt; if (WARN_ON(!count)) return -EINVAL; - order = get_count_order(DIV_ROUND_UP(count, ENTRIES_PER_PAGE)); - - /* - * We want to fill as much as possible. No more than a page - * may be empty. - */ - while ((PAGE_SIZE << order) / ENTRY_SIZE >= count + ENTRIES_PER_PAGE) - order--; + /* We want to fill as much as possible, with no empty pages */ + pages = DIV_ROUND_UP(count, ENTRIES_PER_PAGE); + order = fls(pages) - 1; again: pg->records = (void *)__get_free_pages(GFP_KERNEL | __GFP_ZERO, order); @@ -2264,12 +3854,15 @@ static int ftrace_allocate_records(struct ftrace_page *pg, int count) /* if we can't allocate this size, try something smaller */ if (!order) return -ENOMEM; - order >>= 1; + order--; goto again; } + ftrace_number_of_pages += 1 << order; + ftrace_number_of_groups++; + cnt = (PAGE_SIZE << order) / ENTRY_SIZE; - pg->size = cnt; + pg->order = order; if (cnt > count) cnt = count; @@ -2277,16 +3870,31 @@ static int ftrace_allocate_records(struct ftrace_page *pg, int count) return cnt; } +static void ftrace_free_pages(struct ftrace_page *pages) +{ + struct ftrace_page *pg = pages; + + while (pg) { + if (pg->records) { + free_pages((unsigned long)pg->records, pg->order); + ftrace_number_of_pages -= 1 << pg->order; + } + pages = pg->next; + kfree(pg); + pg = pages; + ftrace_number_of_groups--; + } +} + static struct ftrace_page * ftrace_allocate_pages(unsigned long num_to_init) { struct ftrace_page *start_pg; struct ftrace_page *pg; - int order; int cnt; if (!num_to_init) - return 0; + return NULL; start_pg = pg = kzalloc(sizeof(*pg), GFP_KERNEL); if (!pg) @@ -2316,69 +3924,87 @@ ftrace_allocate_pages(unsigned long num_to_init) return start_pg; free_pages: - while (start_pg) { - order = get_count_order(pg->size / ENTRIES_PER_PAGE); - free_pages((unsigned long)pg->records, order); - start_pg = pg->next; - kfree(pg); - pg = start_pg; - } + ftrace_free_pages(start_pg); pr_info("ftrace: FAILED to allocate memory for functions\n"); return NULL; } -static int __init ftrace_dyn_table_alloc(unsigned long num_to_init) -{ - int cnt; - - if (!num_to_init) { - pr_info("ftrace: No functions to be traced?\n"); - return -1; - } - - cnt = num_to_init / ENTRIES_PER_PAGE; - pr_info("ftrace: allocating %ld entries in %d pages\n", - num_to_init, cnt + 1); - - return 0; -} - #define FTRACE_BUFF_MAX (KSYM_SYMBOL_LEN+4) /* room for wildcards */ struct ftrace_iterator { loff_t pos; loff_t func_pos; + loff_t mod_pos; struct ftrace_page *pg; struct dyn_ftrace *func; struct ftrace_func_probe *probe; + struct ftrace_func_entry *probe_entry; struct trace_parser parser; struct ftrace_hash *hash; struct ftrace_ops *ops; - int hidx; + struct trace_array *tr; + struct list_head *mod_list; + int pidx; int idx; unsigned flags; }; static void * -t_hash_next(struct seq_file *m, loff_t *pos) +t_probe_next(struct seq_file *m, loff_t *pos) { struct ftrace_iterator *iter = m->private; + struct trace_array *tr = iter->ops->private; + struct list_head *func_probes; + struct ftrace_hash *hash; + struct list_head *next; struct hlist_node *hnd = NULL; struct hlist_head *hhd; + int size; (*pos)++; iter->pos = *pos; - if (iter->probe) - hnd = &iter->probe->node; - retry: - if (iter->hidx >= FTRACE_FUNC_HASHSIZE) + if (!tr) + return NULL; + + func_probes = &tr->func_probes; + if (list_empty(func_probes)) + return NULL; + + if (!iter->probe) { + next = func_probes->next; + iter->probe = list_entry(next, struct ftrace_func_probe, list); + } + + if (iter->probe_entry) + hnd = &iter->probe_entry->hlist; + + hash = iter->probe->ops.func_hash->filter_hash; + + /* + * A probe being registered may temporarily have an empty hash + * and it's at the end of the func_probes list. + */ + if (!hash || hash == EMPTY_HASH) return NULL; - hhd = &ftrace_func_hash[iter->hidx]; + size = 1 << hash->size_bits; + + retry: + if (iter->pidx >= size) { + if (iter->probe->list.next == func_probes) + return NULL; + next = iter->probe->list.next; + iter->probe = list_entry(next, struct ftrace_func_probe, list); + hash = iter->probe->ops.func_hash->filter_hash; + size = 1 << hash->size_bits; + iter->pidx = 0; + } + + hhd = &hash->buckets[iter->pidx]; if (hlist_empty(hhd)) { - iter->hidx++; + iter->pidx++; hnd = NULL; goto retry; } @@ -2388,7 +4014,7 @@ t_hash_next(struct seq_file *m, loff_t *pos) else { hnd = hnd->next; if (!hnd) { - iter->hidx++; + iter->pidx++; goto retry; } } @@ -2396,26 +4022,28 @@ t_hash_next(struct seq_file *m, loff_t *pos) if (WARN_ON_ONCE(!hnd)) return NULL; - iter->probe = hlist_entry(hnd, struct ftrace_func_probe, node); + iter->probe_entry = hlist_entry(hnd, struct ftrace_func_entry, hlist); return iter; } -static void *t_hash_start(struct seq_file *m, loff_t *pos) +static void *t_probe_start(struct seq_file *m, loff_t *pos) { struct ftrace_iterator *iter = m->private; void *p = NULL; loff_t l; - if (!(iter->flags & FTRACE_ITER_DO_HASH)) + if (!(iter->flags & FTRACE_ITER_DO_PROBES)) return NULL; - if (iter->func_pos > *pos) + if (iter->mod_pos > *pos) return NULL; - iter->hidx = 0; - for (l = 0; l <= (*pos - iter->func_pos); ) { - p = t_hash_next(m, &l); + iter->probe = NULL; + iter->probe_entry = NULL; + iter->pidx = 0; + for (l = 0; l <= (*pos - iter->mod_pos); ) { + p = t_probe_next(m, &l); if (!p) break; } @@ -2423,50 +4051,118 @@ static void *t_hash_start(struct seq_file *m, loff_t *pos) return NULL; /* Only set this if we have an item */ - iter->flags |= FTRACE_ITER_HASH; + iter->flags |= FTRACE_ITER_PROBE; return iter; } static int -t_hash_show(struct seq_file *m, struct ftrace_iterator *iter) +t_probe_show(struct seq_file *m, struct ftrace_iterator *iter) { - struct ftrace_func_probe *rec; + struct ftrace_func_entry *probe_entry; + struct ftrace_probe_ops *probe_ops; + struct ftrace_func_probe *probe; + + probe = iter->probe; + probe_entry = iter->probe_entry; - rec = iter->probe; - if (WARN_ON_ONCE(!rec)) + if (WARN_ON_ONCE(!probe || !probe_entry)) return -EIO; - if (rec->ops->print) - return rec->ops->print(m, rec->ip, rec->ops, rec->data); + probe_ops = probe->probe_ops; - seq_printf(m, "%ps:%ps", (void *)rec->ip, (void *)rec->ops->func); + if (probe_ops->print) + return probe_ops->print(m, probe_entry->ip, probe_ops, probe->data); - if (rec->data) - seq_printf(m, ":%p", rec->data); - seq_putc(m, '\n'); + seq_printf(m, "%ps:%ps\n", (void *)probe_entry->ip, + (void *)probe_ops->func); return 0; } static void * -t_next(struct seq_file *m, void *v, loff_t *pos) +t_mod_next(struct seq_file *m, loff_t *pos) { struct ftrace_iterator *iter = m->private; - struct ftrace_ops *ops = iter->ops; - struct dyn_ftrace *rec = NULL; + struct trace_array *tr = iter->tr; - if (unlikely(ftrace_disabled)) + (*pos)++; + iter->pos = *pos; + + iter->mod_list = iter->mod_list->next; + + if (iter->mod_list == &tr->mod_trace || + iter->mod_list == &tr->mod_notrace) { + iter->flags &= ~FTRACE_ITER_MOD; + return NULL; + } + + iter->mod_pos = *pos; + + return iter; +} + +static void *t_mod_start(struct seq_file *m, loff_t *pos) +{ + struct ftrace_iterator *iter = m->private; + void *p = NULL; + loff_t l; + + if (iter->func_pos > *pos) return NULL; - if (iter->flags & FTRACE_ITER_HASH) - return t_hash_next(m, pos); + iter->mod_pos = iter->func_pos; - (*pos)++; - iter->pos = iter->func_pos = *pos; + /* probes are only available if tr is set */ + if (!iter->tr) + return NULL; + + for (l = 0; l <= (*pos - iter->func_pos); ) { + p = t_mod_next(m, &l); + if (!p) + break; + } + if (!p) { + iter->flags &= ~FTRACE_ITER_MOD; + return t_probe_start(m, pos); + } + + /* Only set this if we have an item */ + iter->flags |= FTRACE_ITER_MOD; + + return iter; +} + +static int +t_mod_show(struct seq_file *m, struct ftrace_iterator *iter) +{ + struct ftrace_mod_load *ftrace_mod; + struct trace_array *tr = iter->tr; + + if (WARN_ON_ONCE(!iter->mod_list) || + iter->mod_list == &tr->mod_trace || + iter->mod_list == &tr->mod_notrace) + return -EIO; + + ftrace_mod = list_entry(iter->mod_list, struct ftrace_mod_load, list); + + if (ftrace_mod->func) + seq_printf(m, "%s", ftrace_mod->func); + else + seq_putc(m, '*'); + + seq_printf(m, ":mod:%s\n", ftrace_mod->module); + + return 0; +} + +static void * +t_func_next(struct seq_file *m, loff_t *pos) +{ + struct ftrace_iterator *iter = m->private; + struct dyn_ftrace *rec = NULL; - if (iter->flags & FTRACE_ITER_PRINTALL) - return t_hash_start(m, pos); + (*pos)++; retry: if (iter->idx >= iter->pg->index) { @@ -2477,14 +4173,14 @@ t_next(struct seq_file *m, void *v, loff_t *pos) } } else { rec = &iter->pg->records[iter->idx++]; - if (((iter->flags & FTRACE_ITER_FILTER) && - !(ftrace_lookup_ip(ops->filter_hash, rec->ip))) || - - ((iter->flags & FTRACE_ITER_NOTRACE) && - !ftrace_lookup_ip(ops->notrace_hash, rec->ip)) || + if (((iter->flags & (FTRACE_ITER_FILTER | FTRACE_ITER_NOTRACE)) && + !ftrace_lookup_ip(iter->hash, rec->ip)) || ((iter->flags & FTRACE_ITER_ENABLED) && - !(rec->flags & FTRACE_FL_ENABLED))) { + !(rec->flags & FTRACE_FL_ENABLED)) || + + ((iter->flags & FTRACE_ITER_TOUCHED) && + !(rec->flags & FTRACE_FL_TOUCHED))) { rec = NULL; goto retry; @@ -2492,24 +4188,54 @@ t_next(struct seq_file *m, void *v, loff_t *pos) } if (!rec) - return t_hash_start(m, pos); + return NULL; + iter->pos = iter->func_pos = *pos; iter->func = rec; return iter; } +static void * +t_next(struct seq_file *m, void *v, loff_t *pos) +{ + struct ftrace_iterator *iter = m->private; + loff_t l = *pos; /* t_probe_start() must use original pos */ + void *ret; + + if (unlikely(ftrace_disabled)) + return NULL; + + if (iter->flags & FTRACE_ITER_PROBE) + return t_probe_next(m, pos); + + if (iter->flags & FTRACE_ITER_MOD) + return t_mod_next(m, pos); + + if (iter->flags & FTRACE_ITER_PRINTALL) { + /* next must increment pos, and t_probe_start does not */ + (*pos)++; + return t_mod_start(m, &l); + } + + ret = t_func_next(m, pos); + + if (!ret) + return t_mod_start(m, &l); + + return ret; +} + static void reset_iter_read(struct ftrace_iterator *iter) { iter->pos = 0; iter->func_pos = 0; - iter->flags &= ~(FTRACE_ITER_PRINTALL | FTRACE_ITER_HASH); + iter->flags &= ~(FTRACE_ITER_PRINTALL | FTRACE_ITER_PROBE | FTRACE_ITER_MOD); } static void *t_start(struct seq_file *m, loff_t *pos) { struct ftrace_iterator *iter = m->private; - struct ftrace_ops *ops = iter->ops; void *p = NULL; loff_t l; @@ -2529,18 +4255,19 @@ static void *t_start(struct seq_file *m, loff_t *pos) * off, we can short cut and just print out that all * functions are enabled. */ - if (iter->flags & FTRACE_ITER_FILTER && - ftrace_hash_empty(ops->filter_hash)) { + if ((iter->flags & (FTRACE_ITER_FILTER | FTRACE_ITER_NOTRACE)) && + ftrace_hash_empty(iter->hash)) { + iter->func_pos = 1; /* Account for the message */ if (*pos > 0) - return t_hash_start(m, pos); + return t_mod_start(m, pos); iter->flags |= FTRACE_ITER_PRINTALL; /* reset in case of seek/pread */ - iter->flags &= ~FTRACE_ITER_HASH; + iter->flags &= ~FTRACE_ITER_PROBE; return iter; } - if (iter->flags & FTRACE_ITER_HASH) - return t_hash_start(m, pos); + if (iter->flags & FTRACE_ITER_MOD) + return t_mod_start(m, pos); /* * Unfortunately, we need to restart at ftrace_pages_start @@ -2550,13 +4277,13 @@ static void *t_start(struct seq_file *m, loff_t *pos) iter->pg = ftrace_pages_start; iter->idx = 0; for (l = 0; l <= *pos; ) { - p = t_next(m, p, &l); + p = t_func_next(m, &l); if (!p) break; } if (!p) - return t_hash_start(m, pos); + return t_mod_start(m, pos); return iter; } @@ -2566,16 +4293,173 @@ static void t_stop(struct seq_file *m, void *p) mutex_unlock(&ftrace_lock); } +void * __weak +arch_ftrace_trampoline_func(struct ftrace_ops *ops, struct dyn_ftrace *rec) +{ + return NULL; +} + +static void add_trampoline_func(struct seq_file *m, struct ftrace_ops *ops, + struct dyn_ftrace *rec) +{ + void *ptr; + + ptr = arch_ftrace_trampoline_func(ops, rec); + if (ptr) + seq_printf(m, " ->%pS", ptr); +} + +#ifdef FTRACE_MCOUNT_MAX_OFFSET +/* + * Weak functions can still have an mcount/fentry that is saved in + * the __mcount_loc section. These can be detected by having a + * symbol offset of greater than FTRACE_MCOUNT_MAX_OFFSET, as the + * symbol found by kallsyms is not the function that the mcount/fentry + * is part of. The offset is much greater in these cases. + * + * Test the record to make sure that the ip points to a valid kallsyms + * and if not, mark it disabled. + */ +static int test_for_valid_rec(struct dyn_ftrace *rec) +{ + char str[KSYM_SYMBOL_LEN]; + unsigned long offset; + const char *ret; + + ret = kallsyms_lookup(rec->ip, NULL, &offset, NULL, str); + + /* Weak functions can cause invalid addresses */ + if (!ret || offset > FTRACE_MCOUNT_MAX_OFFSET) { + rec->flags |= FTRACE_FL_DISABLED; + return 0; + } + return 1; +} + +static struct workqueue_struct *ftrace_check_wq __initdata; +static struct work_struct ftrace_check_work __initdata; + +/* + * Scan all the mcount/fentry entries to make sure they are valid. + */ +static __init void ftrace_check_work_func(struct work_struct *work) +{ + struct ftrace_page *pg; + struct dyn_ftrace *rec; + + mutex_lock(&ftrace_lock); + do_for_each_ftrace_rec(pg, rec) { + test_for_valid_rec(rec); + } while_for_each_ftrace_rec(); + mutex_unlock(&ftrace_lock); +} + +static int __init ftrace_check_for_weak_functions(void) +{ + INIT_WORK(&ftrace_check_work, ftrace_check_work_func); + + ftrace_check_wq = alloc_workqueue("ftrace_check_wq", WQ_UNBOUND, 0); + + queue_work(ftrace_check_wq, &ftrace_check_work); + return 0; +} + +static int __init ftrace_check_sync(void) +{ + /* Make sure the ftrace_check updates are finished */ + if (ftrace_check_wq) + destroy_workqueue(ftrace_check_wq); + return 0; +} + +late_initcall_sync(ftrace_check_sync); +subsys_initcall(ftrace_check_for_weak_functions); + +static int print_rec(struct seq_file *m, unsigned long ip) +{ + unsigned long offset; + char str[KSYM_SYMBOL_LEN]; + char *modname; + const char *ret; + + ret = kallsyms_lookup(ip, NULL, &offset, &modname, str); + /* Weak functions can cause invalid addresses */ + if (!ret || offset > FTRACE_MCOUNT_MAX_OFFSET) { + snprintf(str, KSYM_SYMBOL_LEN, "%s_%ld", + FTRACE_INVALID_FUNCTION, offset); + ret = NULL; + } + + seq_puts(m, str); + if (modname) + seq_printf(m, " [%s]", modname); + return ret == NULL ? -1 : 0; +} +#else +static inline int test_for_valid_rec(struct dyn_ftrace *rec) +{ + return 1; +} + +static inline int print_rec(struct seq_file *m, unsigned long ip) +{ + seq_printf(m, "%ps", (void *)ip); + return 0; +} +#endif + +static void print_subops(struct seq_file *m, struct ftrace_ops *ops, struct dyn_ftrace *rec) +{ + struct ftrace_ops *subops; + bool first = true; + + list_for_each_entry(subops, &ops->subop_list, list) { + if (!((subops->flags & FTRACE_OPS_FL_ENABLED) && + hash_contains_ip(rec->ip, subops->func_hash))) + continue; + if (first) { + seq_printf(m, "\tsubops:"); + first = false; + } +#ifdef CONFIG_FUNCTION_GRAPH_TRACER + if (subops->flags & FTRACE_OPS_FL_GRAPH) { + struct fgraph_ops *gops; + + gops = container_of(subops, struct fgraph_ops, ops); + seq_printf(m, " {ent:%pS ret:%pS}", + (void *)gops->entryfunc, + (void *)gops->retfunc); + continue; + } +#endif + if (subops->trampoline) { + seq_printf(m, " {%pS (%pS)}", + (void *)subops->trampoline, + (void *)subops->func); + add_trampoline_func(m, subops, rec); + } else { + seq_printf(m, " {%pS}", + (void *)subops->func); + } + } +} + static int t_show(struct seq_file *m, void *v) { struct ftrace_iterator *iter = m->private; struct dyn_ftrace *rec; - if (iter->flags & FTRACE_ITER_HASH) - return t_hash_show(m, iter); + if (iter->flags & FTRACE_ITER_PROBE) + return t_probe_show(m, iter); + + if (iter->flags & FTRACE_ITER_MOD) + return t_mod_show(m, iter); if (iter->flags & FTRACE_ITER_PRINTALL) { - seq_printf(m, "#### all functions enabled ####\n"); + if (iter->flags & FTRACE_ITER_NOTRACE) + seq_puts(m, "#### no functions disabled ####\n"); + else + seq_puts(m, "#### all functions enabled ####\n"); return 0; } @@ -2584,12 +4468,62 @@ static int t_show(struct seq_file *m, void *v) if (!rec) return 0; - seq_printf(m, "%ps", (void *)rec->ip); - if (iter->flags & FTRACE_ITER_ENABLED) - seq_printf(m, " (%ld)%s", - rec->flags & ~FTRACE_FL_MASK, - rec->flags & FTRACE_FL_REGS ? " R" : ""); - seq_printf(m, "\n"); + if (iter->flags & FTRACE_ITER_ADDRS) + seq_printf(m, "%lx ", rec->ip); + + if (print_rec(m, rec->ip)) { + /* This should only happen when a rec is disabled */ + WARN_ON_ONCE(!(rec->flags & FTRACE_FL_DISABLED)); + seq_putc(m, '\n'); + return 0; + } + + if (iter->flags & (FTRACE_ITER_ENABLED | FTRACE_ITER_TOUCHED)) { + struct ftrace_ops *ops; + + seq_printf(m, " (%ld)%s%s%s%s%s", + ftrace_rec_count(rec), + rec->flags & FTRACE_FL_REGS ? " R" : " ", + rec->flags & FTRACE_FL_IPMODIFY ? " I" : " ", + rec->flags & FTRACE_FL_DIRECT ? " D" : " ", + rec->flags & FTRACE_FL_CALL_OPS ? " O" : " ", + rec->flags & FTRACE_FL_MODIFIED ? " M " : " "); + if (rec->flags & FTRACE_FL_TRAMP_EN) { + ops = ftrace_find_tramp_ops_any(rec); + if (ops) { + do { + seq_printf(m, "\ttramp: %pS (%pS)", + (void *)ops->trampoline, + (void *)ops->func); + add_trampoline_func(m, ops, rec); + print_subops(m, ops, rec); + ops = ftrace_find_tramp_ops_next(rec, ops); + } while (ops); + } else + seq_puts(m, "\ttramp: ERROR!"); + } else { + add_trampoline_func(m, NULL, rec); + } + if (rec->flags & FTRACE_FL_CALL_OPS_EN) { + ops = ftrace_find_unique_ops(rec); + if (ops) { + seq_printf(m, "\tops: %pS (%pS)", + ops, ops->func); + print_subops(m, ops, rec); + } else { + seq_puts(m, "\tops: ERROR!"); + } + } + if (rec->flags & FTRACE_FL_DIRECT) { + unsigned long direct; + + direct = ftrace_find_rec_direct(rec->ip); + if (direct) + seq_printf(m, "\n\tdirect-->%pS", (void *)direct); + } + } + + seq_putc(m, '\n'); return 0; } @@ -2605,17 +4539,23 @@ static int ftrace_avail_open(struct inode *inode, struct file *file) { struct ftrace_iterator *iter; + int ret; + + ret = security_locked_down(LOCKDOWN_TRACEFS); + if (ret) + return ret; if (unlikely(ftrace_disabled)) return -ENODEV; iter = __seq_open_private(file, &show_ftrace_seq_ops, sizeof(*iter)); - if (iter) { - iter->pg = ftrace_pages_start; - iter->ops = &global_ops; - } + if (!iter) + return -ENOMEM; + + iter->pg = ftrace_pages_start; + iter->ops = &global_ops; - return iter ? 0 : -ENOMEM; + return 0; } static int @@ -2623,24 +4563,73 @@ ftrace_enabled_open(struct inode *inode, struct file *file) { struct ftrace_iterator *iter; - if (unlikely(ftrace_disabled)) - return -ENODEV; + /* + * This shows us what functions are currently being + * traced and by what. Not sure if we want lockdown + * to hide such critical information for an admin. + * Although, perhaps it can show information we don't + * want people to see, but if something is tracing + * something, we probably want to know about it. + */ iter = __seq_open_private(file, &show_ftrace_seq_ops, sizeof(*iter)); - if (iter) { - iter->pg = ftrace_pages_start; - iter->flags = FTRACE_ITER_ENABLED; - iter->ops = &global_ops; - } + if (!iter) + return -ENOMEM; + + iter->pg = ftrace_pages_start; + iter->flags = FTRACE_ITER_ENABLED; + iter->ops = &global_ops; - return iter ? 0 : -ENOMEM; + return 0; } -static void ftrace_filter_reset(struct ftrace_hash *hash) +static int +ftrace_touched_open(struct inode *inode, struct file *file) { - mutex_lock(&ftrace_lock); - ftrace_hash_clear(hash); - mutex_unlock(&ftrace_lock); + struct ftrace_iterator *iter; + + /* + * This shows us what functions have ever been enabled + * (traced, direct, patched, etc). Not sure if we want lockdown + * to hide such critical information for an admin. + * Although, perhaps it can show information we don't + * want people to see, but if something had traced + * something, we probably want to know about it. + */ + + iter = __seq_open_private(file, &show_ftrace_seq_ops, sizeof(*iter)); + if (!iter) + return -ENOMEM; + + iter->pg = ftrace_pages_start; + iter->flags = FTRACE_ITER_TOUCHED; + iter->ops = &global_ops; + + return 0; +} + +static int +ftrace_avail_addrs_open(struct inode *inode, struct file *file) +{ + struct ftrace_iterator *iter; + int ret; + + ret = security_locked_down(LOCKDOWN_TRACEFS); + if (ret) + return ret; + + if (unlikely(ftrace_disabled)) + return -ENODEV; + + iter = __seq_open_private(file, &show_ftrace_seq_ops, sizeof(*iter)); + if (!iter) + return -ENOMEM; + + iter->pg = ftrace_pages_start; + iter->flags = FTRACE_ITER_ADDRS; + iter->ops = &global_ops; + + return 0; } /** @@ -2656,8 +4645,10 @@ static void ftrace_filter_reset(struct ftrace_hash *hash) * routine, you can use ftrace_filter_write() for the write * routine if @flag has FTRACE_ITER_FILTER set, or * ftrace_notrace_write() if @flag has FTRACE_ITER_NOTRACE set. - * ftrace_filter_lseek() should be used as the lseek routine, and + * tracing_lseek() should be used as the lseek routine, and * release must call ftrace_regex_release(). + * + * Returns: 0 on success or a negative errno value on failure */ int ftrace_regex_open(struct ftrace_ops *ops, int flag, @@ -2665,45 +4656,63 @@ ftrace_regex_open(struct ftrace_ops *ops, int flag, { struct ftrace_iterator *iter; struct ftrace_hash *hash; - int ret = 0; + struct list_head *mod_head; + struct trace_array *tr = ops->private; + int ret = -ENOMEM; ftrace_ops_init(ops); if (unlikely(ftrace_disabled)) return -ENODEV; + if (tracing_check_open_get_tr(tr)) + return -ENODEV; + iter = kzalloc(sizeof(*iter), GFP_KERNEL); if (!iter) - return -ENOMEM; + goto out; - if (trace_parser_get_init(&iter->parser, FTRACE_BUFF_MAX)) { - kfree(iter); - return -ENOMEM; - } + if (trace_parser_get_init(&iter->parser, FTRACE_BUFF_MAX)) + goto out; iter->ops = ops; iter->flags = flag; + iter->tr = tr; - mutex_lock(&ops->regex_lock); + mutex_lock(&ops->func_hash->regex_lock); - if (flag & FTRACE_ITER_NOTRACE) - hash = ops->notrace_hash; - else - hash = ops->filter_hash; + if (flag & FTRACE_ITER_NOTRACE) { + hash = ops->func_hash->notrace_hash; + mod_head = tr ? &tr->mod_notrace : NULL; + } else { + hash = ops->func_hash->filter_hash; + mod_head = tr ? &tr->mod_trace : NULL; + } + + iter->mod_list = mod_head; if (file->f_mode & FMODE_WRITE) { - iter->hash = alloc_and_copy_ftrace_hash(FTRACE_HASH_DEFAULT_BITS, hash); - if (!iter->hash) { - trace_parser_put(&iter->parser); - kfree(iter); - ret = -ENOMEM; - goto out_unlock; + const int size_bits = FTRACE_HASH_DEFAULT_BITS; + + if (file->f_flags & O_TRUNC) { + iter->hash = alloc_ftrace_hash(size_bits); + clear_ftrace_mod_list(mod_head); + } else { + iter->hash = alloc_and_copy_ftrace_hash(size_bits, hash); } + } else { + if (hash) + iter->hash = alloc_and_copy_ftrace_hash(hash->size_bits, hash); + else + iter->hash = EMPTY_HASH; } - if ((file->f_mode & FMODE_WRITE) && - (file->f_flags & O_TRUNC)) - ftrace_filter_reset(iter->hash); + if (!iter->hash) { + trace_parser_put(&iter->parser); + goto out_unlock; + } + + ret = 0; if (file->f_mode & FMODE_READ) { iter->pg = ftrace_pages_start; @@ -2716,13 +4725,19 @@ ftrace_regex_open(struct ftrace_ops *ops, int flag, /* Failed */ free_ftrace_hash(iter->hash); trace_parser_put(&iter->parser); - kfree(iter); } } else file->private_data = iter; out_unlock: - mutex_unlock(&ops->regex_lock); + mutex_unlock(&ops->func_hash->regex_lock); + + out: + if (ret) { + kfree(iter); + if (tr) + trace_array_put(tr); + } return ret; } @@ -2730,39 +4745,69 @@ ftrace_regex_open(struct ftrace_ops *ops, int flag, static int ftrace_filter_open(struct inode *inode, struct file *file) { - return ftrace_regex_open(&global_ops, - FTRACE_ITER_FILTER | FTRACE_ITER_DO_HASH, + struct ftrace_ops *ops = inode->i_private; + + /* Checks for tracefs lockdown */ + return ftrace_regex_open(ops, + FTRACE_ITER_FILTER | FTRACE_ITER_DO_PROBES, inode, file); } static int ftrace_notrace_open(struct inode *inode, struct file *file) { - return ftrace_regex_open(&global_ops, FTRACE_ITER_NOTRACE, + struct ftrace_ops *ops = inode->i_private; + + /* Checks for tracefs lockdown */ + return ftrace_regex_open(ops, FTRACE_ITER_NOTRACE, inode, file); } -static int ftrace_match(char *str, char *regex, int len, int type) +/* Type for quick search ftrace basic regexes (globs) from filter_parse_regex */ +struct ftrace_glob { + char *search; + unsigned len; + int type; +}; + +/* + * If symbols in an architecture don't correspond exactly to the user-visible + * name of what they represent, it is possible to define this function to + * perform the necessary adjustments. +*/ +char * __weak arch_ftrace_match_adjust(char *str, const char *search) +{ + return str; +} + +static int ftrace_match(char *str, struct ftrace_glob *g) { int matched = 0; int slen; - switch (type) { + str = arch_ftrace_match_adjust(str, g->search); + + switch (g->type) { case MATCH_FULL: - if (strcmp(str, regex) == 0) + if (strcmp(str, g->search) == 0) matched = 1; break; case MATCH_FRONT_ONLY: - if (strncmp(str, regex, len) == 0) + if (strncmp(str, g->search, g->len) == 0) matched = 1; break; case MATCH_MIDDLE_ONLY: - if (strstr(str, regex)) + if (strstr(str, g->search)) matched = 1; break; case MATCH_END_ONLY: slen = strlen(str); - if (slen >= len && memcmp(str + slen - len, regex, len) == 0) + if (slen >= g->len && + memcmp(str + slen - g->len, g->search, g->len) == 0) + matched = 1; + break; + case MATCH_GLOB: + if (glob_match(g->search, str)) matched = 1; break; } @@ -2771,13 +4816,13 @@ static int ftrace_match(char *str, char *regex, int len, int type) } static int -enter_record(struct ftrace_hash *hash, struct dyn_ftrace *rec, int not) +enter_record(struct ftrace_hash *hash, struct dyn_ftrace *rec, int clear_filter) { struct ftrace_func_entry *entry; int ret = 0; entry = ftrace_lookup_ip(hash, rec->ip); - if (not) { + if (clear_filter) { /* Do nothing if it doesn't exist */ if (!entry) return 0; @@ -2787,68 +4832,144 @@ enter_record(struct ftrace_hash *hash, struct dyn_ftrace *rec, int not) /* Do nothing if it exists */ if (entry) return 0; - - ret = add_hash_entry(hash, rec->ip); + if (add_hash_entry(hash, rec->ip) == NULL) + ret = -ENOMEM; } return ret; } static int -ftrace_match_record(struct dyn_ftrace *rec, char *mod, - char *regex, int len, int type) +add_rec_by_index(struct ftrace_hash *hash, struct ftrace_glob *func_g, + int clear_filter) +{ + long index; + struct ftrace_page *pg; + struct dyn_ftrace *rec; + + /* The index starts at 1 */ + if (kstrtoul(func_g->search, 0, &index) || --index < 0) + return 0; + + do_for_each_ftrace_rec(pg, rec) { + if (pg->index <= index) { + index -= pg->index; + /* this is a double loop, break goes to the next page */ + break; + } + rec = &pg->records[index]; + enter_record(hash, rec, clear_filter); + return 1; + } while_for_each_ftrace_rec(); + return 0; +} + +#ifdef FTRACE_MCOUNT_MAX_OFFSET +static int lookup_ip(unsigned long ip, char **modname, char *str) +{ + unsigned long offset; + + kallsyms_lookup(ip, NULL, &offset, modname, str); + if (offset > FTRACE_MCOUNT_MAX_OFFSET) + return -1; + return 0; +} +#else +static int lookup_ip(unsigned long ip, char **modname, char *str) +{ + kallsyms_lookup(ip, NULL, NULL, modname, str); + return 0; +} +#endif + +static int +ftrace_match_record(struct dyn_ftrace *rec, struct ftrace_glob *func_g, + struct ftrace_glob *mod_g, int exclude_mod) { char str[KSYM_SYMBOL_LEN]; char *modname; - kallsyms_lookup(rec->ip, NULL, NULL, &modname, str); + if (lookup_ip(rec->ip, &modname, str)) { + /* This should only happen when a rec is disabled */ + WARN_ON_ONCE(system_state == SYSTEM_RUNNING && + !(rec->flags & FTRACE_FL_DISABLED)); + return 0; + } + + if (mod_g) { + int mod_matches = (modname) ? ftrace_match(modname, mod_g) : 0; - if (mod) { - /* module lookup requires matching the module */ - if (!modname || strcmp(modname, mod)) + /* blank module name to match all modules */ + if (!mod_g->len) { + /* blank module globbing: modname xor exclude_mod */ + if (!exclude_mod != !modname) + goto func_match; return 0; + } + /* + * exclude_mod is set to trace everything but the given + * module. If it is set and the module matches, then + * return 0. If it is not set, and the module doesn't match + * also return 0. Otherwise, check the function to see if + * that matches. + */ + if (!mod_matches == !exclude_mod) + return 0; +func_match: /* blank search means to match all funcs in the mod */ - if (!len) + if (!func_g->len) return 1; } - return ftrace_match(str, regex, len, type); + return ftrace_match(str, func_g); } static int -match_records(struct ftrace_hash *hash, char *buff, - int len, char *mod, int not) +match_records(struct ftrace_hash *hash, char *func, int len, char *mod) { - unsigned search_len = 0; struct ftrace_page *pg; struct dyn_ftrace *rec; - int type = MATCH_FULL; - char *search = buff; + struct ftrace_glob func_g = { .type = MATCH_FULL }; + struct ftrace_glob mod_g = { .type = MATCH_FULL }; + struct ftrace_glob *mod_match = (mod) ? &mod_g : NULL; + int exclude_mod = 0; int found = 0; int ret; + int clear_filter = 0; - if (len) { - type = filter_parse_regex(buff, len, &search, ¬); - search_len = strlen(search); + if (func) { + func_g.type = filter_parse_regex(func, len, &func_g.search, + &clear_filter); + func_g.len = strlen(func_g.search); } - mutex_lock(&ftrace_lock); + if (mod) { + mod_g.type = filter_parse_regex(mod, strlen(mod), + &mod_g.search, &exclude_mod); + mod_g.len = strlen(mod_g.search); + } + + guard(mutex)(&ftrace_lock); if (unlikely(ftrace_disabled)) - goto out_unlock; + return 0; + + if (func_g.type == MATCH_INDEX) + return add_rec_by_index(hash, &func_g, clear_filter); do_for_each_ftrace_rec(pg, rec) { - if (ftrace_match_record(rec, mod, search, search_len, type)) { - ret = enter_record(hash, rec, not); - if (ret < 0) { - found = ret; - goto out_unlock; - } + + if (rec->flags & FTRACE_FL_DISABLED) + continue; + + if (ftrace_match_record(rec, &func_g, mod_match, exclude_mod)) { + ret = enter_record(hash, rec, clear_filter); + if (ret < 0) + return ret; found = 1; } + cond_resched(); } while_for_each_ftrace_rec(); - out_unlock: - mutex_unlock(&ftrace_lock); return found; } @@ -2856,38 +4977,223 @@ match_records(struct ftrace_hash *hash, char *buff, static int ftrace_match_records(struct ftrace_hash *hash, char *buff, int len) { - return match_records(hash, buff, len, NULL, 0); + return match_records(hash, buff, len, NULL); } -static int -ftrace_match_module_records(struct ftrace_hash *hash, char *buff, char *mod) +static void ftrace_ops_update_code(struct ftrace_ops *ops, + struct ftrace_ops_hash *old_hash) { - int not = 0; + struct ftrace_ops *op; - /* blank or '*' mean the same */ - if (strcmp(buff, "*") == 0) - buff[0] = 0; + if (!ftrace_enabled) + return; + + if (ops->flags & FTRACE_OPS_FL_ENABLED) { + ftrace_run_modify_code(ops, FTRACE_UPDATE_CALLS, old_hash); + return; + } - /* handle the case of 'dont filter this module' */ - if (strcmp(buff, "!") == 0 || strcmp(buff, "!*") == 0) { - buff[0] = 0; - not = 1; + /* + * If this is the shared global_ops filter, then we need to + * check if there is another ops that shares it, is enabled. + * If so, we still need to run the modify code. + */ + if (ops->func_hash != &global_ops.local_hash) + return; + + do_for_each_ftrace_op(op, ftrace_ops_list) { + if (op->func_hash == &global_ops.local_hash && + op->flags & FTRACE_OPS_FL_ENABLED) { + ftrace_run_modify_code(op, FTRACE_UPDATE_CALLS, old_hash); + /* Only need to do this once */ + return; + } + } while_for_each_ftrace_op(op); +} + +static int ftrace_hash_move_and_update_ops(struct ftrace_ops *ops, + struct ftrace_hash **orig_hash, + struct ftrace_hash *hash, + int enable) +{ + if (ops->flags & FTRACE_OPS_FL_SUBOP) + return ftrace_hash_move_and_update_subops(ops, orig_hash, hash); + + /* + * If this ops is not enabled, it could be sharing its filters + * with a subop. If that's the case, update the subop instead of + * this ops. Shared filters are only allowed to have one ops set + * at a time, and if we update the ops that is not enabled, + * it will not affect subops that share it. + */ + if (!(ops->flags & FTRACE_OPS_FL_ENABLED)) { + struct ftrace_ops *op; + + /* Check if any other manager subops maps to this hash */ + do_for_each_ftrace_op(op, ftrace_ops_list) { + struct ftrace_ops *subops; + + list_for_each_entry(subops, &op->subop_list, list) { + if ((subops->flags & FTRACE_OPS_FL_ENABLED) && + subops->func_hash == ops->func_hash) { + return ftrace_hash_move_and_update_subops(subops, orig_hash, hash); + } + } + } while_for_each_ftrace_op(op); } - return match_records(hash, buff, strlen(buff), mod, not); + return __ftrace_hash_move_and_update_ops(ops, orig_hash, hash, enable); } +static int cache_mod(struct trace_array *tr, + const char *func, char *module, int enable) +{ + struct ftrace_mod_load *ftrace_mod, *n; + struct list_head *head = enable ? &tr->mod_trace : &tr->mod_notrace; + + guard(mutex)(&ftrace_lock); + + /* We do not cache inverse filters */ + if (func[0] == '!') { + int ret = -EINVAL; + + func++; + + /* Look to remove this hash */ + list_for_each_entry_safe(ftrace_mod, n, head, list) { + if (strcmp(ftrace_mod->module, module) != 0) + continue; + + /* no func matches all */ + if (strcmp(func, "*") == 0 || + (ftrace_mod->func && + strcmp(ftrace_mod->func, func) == 0)) { + ret = 0; + free_ftrace_mod(ftrace_mod); + continue; + } + } + return ret; + } + + /* We only care about modules that have not been loaded yet */ + if (module_exists(module)) + return -EINVAL; + + /* Save this string off, and execute it when the module is loaded */ + return ftrace_add_mod(tr, func, module, enable); +} + +#ifdef CONFIG_MODULES +static void process_mod_list(struct list_head *head, struct ftrace_ops *ops, + char *mod, bool enable) +{ + struct ftrace_mod_load *ftrace_mod, *n; + struct ftrace_hash **orig_hash, *new_hash; + LIST_HEAD(process_mods); + char *func; + + mutex_lock(&ops->func_hash->regex_lock); + + if (enable) + orig_hash = &ops->func_hash->filter_hash; + else + orig_hash = &ops->func_hash->notrace_hash; + + new_hash = alloc_and_copy_ftrace_hash(FTRACE_HASH_DEFAULT_BITS, + *orig_hash); + if (!new_hash) + goto out; /* warn? */ + + mutex_lock(&ftrace_lock); + + list_for_each_entry_safe(ftrace_mod, n, head, list) { + + if (strcmp(ftrace_mod->module, mod) != 0) + continue; + + if (ftrace_mod->func) + func = kstrdup(ftrace_mod->func, GFP_KERNEL); + else + func = kstrdup("*", GFP_KERNEL); + + if (!func) /* warn? */ + continue; + + list_move(&ftrace_mod->list, &process_mods); + + /* Use the newly allocated func, as it may be "*" */ + kfree(ftrace_mod->func); + ftrace_mod->func = func; + } + + mutex_unlock(&ftrace_lock); + + list_for_each_entry_safe(ftrace_mod, n, &process_mods, list) { + + func = ftrace_mod->func; + + /* Grabs ftrace_lock, which is why we have this extra step */ + match_records(new_hash, func, strlen(func), mod); + free_ftrace_mod(ftrace_mod); + } + + if (enable && list_empty(head)) + new_hash->flags &= ~FTRACE_HASH_FL_MOD; + + mutex_lock(&ftrace_lock); + + ftrace_hash_move_and_update_ops(ops, orig_hash, + new_hash, enable); + mutex_unlock(&ftrace_lock); + + out: + mutex_unlock(&ops->func_hash->regex_lock); + + free_ftrace_hash(new_hash); +} + +static void process_cached_mods(const char *mod_name) +{ + struct trace_array *tr; + char *mod; + + mod = kstrdup(mod_name, GFP_KERNEL); + if (!mod) + return; + + mutex_lock(&trace_types_lock); + list_for_each_entry(tr, &ftrace_trace_arrays, list) { + if (!list_empty(&tr->mod_trace)) + process_mod_list(&tr->mod_trace, tr->ops, mod, true); + if (!list_empty(&tr->mod_notrace)) + process_mod_list(&tr->mod_notrace, tr->ops, mod, false); + } + mutex_unlock(&trace_types_lock); + + kfree(mod); +} +#endif + /* * We register the module command as a template to show others how * to register the a command as well. */ static int -ftrace_mod_callback(struct ftrace_hash *hash, - char *func, char *cmd, char *param, int enable) +ftrace_mod_callback(struct trace_array *tr, struct ftrace_hash *hash, + char *func_orig, char *cmd, char *module, int enable) { - char *mod; - int ret = -EINVAL; + char *func; + int ret; + + if (!tr) + return -ENODEV; + + /* match_records() modifies func, and we need the original */ + func = kstrdup(func_orig, GFP_KERNEL); + if (!func) + return -ENOMEM; /* * cmd == 'mod' because we only registered this func @@ -2896,21 +5202,13 @@ ftrace_mod_callback(struct ftrace_hash *hash, * you can tell which command was used by the cmd * parameter. */ + ret = match_records(hash, func, strlen(func), module); + kfree(func); - /* we must have a module name */ - if (!param) - return ret; - - mod = strsep(¶m, ":"); - if (!strlen(mod)) - return ret; - - ret = ftrace_match_module_records(hash, func, mod); if (!ret) - ret = -EINVAL; + return cache_mod(tr, func_orig, module, enable); if (ret < 0) return ret; - return 0; } @@ -2926,18 +5224,13 @@ static int __init ftrace_mod_cmd_init(void) core_initcall(ftrace_mod_cmd_init); static void function_trace_probe_call(unsigned long ip, unsigned long parent_ip, - struct ftrace_ops *op, struct pt_regs *pt_regs) + struct ftrace_ops *op, struct ftrace_regs *fregs) { - struct ftrace_func_probe *entry; - struct hlist_head *hhd; - unsigned long key; + struct ftrace_probe_ops *probe_ops; + struct ftrace_func_probe *probe; - key = hash_long(ip, FTRACE_HASH_BITS); - - hhd = &ftrace_func_hash[key]; - - if (hlist_empty(hhd)) - return; + probe = container_of(op, struct ftrace_func_probe, ops); + probe_ops = probe->probe_ops; /* * Disable preemption for these calls to prevent a RCU grace @@ -2945,334 +5238,525 @@ static void function_trace_probe_call(unsigned long ip, unsigned long parent_ip, * on the hash. rcu_read_lock is too dangerous here. */ preempt_disable_notrace(); - hlist_for_each_entry_rcu_notrace(entry, hhd, node) { - if (entry->ip == ip) - entry->ops->func(ip, parent_ip, &entry->data); - } + probe_ops->func(ip, parent_ip, probe->tr, probe_ops, probe->data); preempt_enable_notrace(); } -static struct ftrace_ops trace_probe_ops __read_mostly = -{ - .func = function_trace_probe_call, - .flags = FTRACE_OPS_FL_INITIALIZED, - INIT_REGEX_LOCK(trace_probe_ops) +struct ftrace_func_map { + struct ftrace_func_entry entry; + void *data; }; -static int ftrace_probe_registered; +/* + * Note, ftrace_func_mapper is freed by free_ftrace_hash(&mapper->hash). + * The hash field must be the first field. + */ +struct ftrace_func_mapper { + struct ftrace_hash hash; /* Must be first! */ +}; -static void __enable_ftrace_function_probe(void) +/** + * allocate_ftrace_func_mapper - allocate a new ftrace_func_mapper + * + * Returns: a ftrace_func_mapper descriptor that can be used to map ips to data. + */ +struct ftrace_func_mapper *allocate_ftrace_func_mapper(void) { - int ret; - int i; + struct ftrace_hash *hash; - if (ftrace_probe_registered) { - /* still need to update the function call sites */ - if (ftrace_enabled) - ftrace_run_update_code(FTRACE_UPDATE_CALLS); - return; - } + /* + * The mapper is simply a ftrace_hash, but since the entries + * in the hash are not ftrace_func_entry type, we define it + * as a separate structure. + */ + hash = alloc_ftrace_hash(FTRACE_HASH_DEFAULT_BITS); + return (struct ftrace_func_mapper *)hash; +} - for (i = 0; i < FTRACE_FUNC_HASHSIZE; i++) { - struct hlist_head *hhd = &ftrace_func_hash[i]; - if (hhd->first) - break; - } - /* Nothing registered? */ - if (i == FTRACE_FUNC_HASHSIZE) - return; +/** + * ftrace_func_mapper_find_ip - Find some data mapped to an ip + * @mapper: The mapper that has the ip maps + * @ip: the instruction pointer to find the data for + * + * Returns: the data mapped to @ip if found otherwise NULL. The return + * is actually the address of the mapper data pointer. The address is + * returned for use cases where the data is no bigger than a long, and + * the user can use the data pointer as its data instead of having to + * allocate more memory for the reference. + */ +void **ftrace_func_mapper_find_ip(struct ftrace_func_mapper *mapper, + unsigned long ip) +{ + struct ftrace_func_entry *entry; + struct ftrace_func_map *map; - ret = __register_ftrace_function(&trace_probe_ops); - if (!ret) - ret = ftrace_startup(&trace_probe_ops, 0); + entry = ftrace_lookup_ip(&mapper->hash, ip); + if (!entry) + return NULL; - ftrace_probe_registered = 1; + map = (struct ftrace_func_map *)entry; + return &map->data; } -static void __disable_ftrace_function_probe(void) +/** + * ftrace_func_mapper_add_ip - Map some data to an ip + * @mapper: The mapper that has the ip maps + * @ip: The instruction pointer address to map @data to + * @data: The data to map to @ip + * + * Returns: 0 on success otherwise an error. + */ +int ftrace_func_mapper_add_ip(struct ftrace_func_mapper *mapper, + unsigned long ip, void *data) { - int ret; - int i; + struct ftrace_func_entry *entry; + struct ftrace_func_map *map; + + entry = ftrace_lookup_ip(&mapper->hash, ip); + if (entry) + return -EBUSY; + + map = kmalloc(sizeof(*map), GFP_KERNEL); + if (!map) + return -ENOMEM; + + map->entry.ip = ip; + map->data = data; + + __add_hash_entry(&mapper->hash, &map->entry); + + return 0; +} + +/** + * ftrace_func_mapper_remove_ip - Remove an ip from the mapping + * @mapper: The mapper that has the ip maps + * @ip: The instruction pointer address to remove the data from + * + * Returns: the data if it is found, otherwise NULL. + * Note, if the data pointer is used as the data itself, (see + * ftrace_func_mapper_find_ip(), then the return value may be meaningless, + * if the data pointer was set to zero. + */ +void *ftrace_func_mapper_remove_ip(struct ftrace_func_mapper *mapper, + unsigned long ip) +{ + struct ftrace_func_entry *entry; + struct ftrace_func_map *map; + void *data; + + entry = ftrace_lookup_ip(&mapper->hash, ip); + if (!entry) + return NULL; + + map = (struct ftrace_func_map *)entry; + data = map->data; + + remove_hash_entry(&mapper->hash, entry); + kfree(entry); + + return data; +} + +/** + * free_ftrace_func_mapper - free a mapping of ips and data + * @mapper: The mapper that has the ip maps + * @free_func: A function to be called on each data item. + * + * This is used to free the function mapper. The @free_func is optional + * and can be used if the data needs to be freed as well. + */ +void free_ftrace_func_mapper(struct ftrace_func_mapper *mapper, + ftrace_mapper_func free_func) +{ + struct ftrace_func_entry *entry; + struct ftrace_func_map *map; + struct hlist_head *hhd; + int size, i; - if (!ftrace_probe_registered) + if (!mapper) return; - for (i = 0; i < FTRACE_FUNC_HASHSIZE; i++) { - struct hlist_head *hhd = &ftrace_func_hash[i]; - if (hhd->first) - return; + if (free_func && mapper->hash.count) { + size = 1 << mapper->hash.size_bits; + for (i = 0; i < size; i++) { + hhd = &mapper->hash.buckets[i]; + hlist_for_each_entry(entry, hhd, hlist) { + map = (struct ftrace_func_map *)entry; + free_func(map); + } + } } + /* This also frees the mapper itself */ + free_ftrace_hash(&mapper->hash); +} - /* no more funcs left */ - ret = __unregister_ftrace_function(&trace_probe_ops); - if (!ret) - ftrace_shutdown(&trace_probe_ops, 0); +static void release_probe(struct ftrace_func_probe *probe) +{ + struct ftrace_probe_ops *probe_ops; - ftrace_probe_registered = 0; -} + guard(mutex)(&ftrace_lock); + WARN_ON(probe->ref <= 0); -static void ftrace_free_entry(struct ftrace_func_probe *entry) + /* Subtract the ref that was used to protect this instance */ + probe->ref--; + + if (!probe->ref) { + probe_ops = probe->probe_ops; + /* + * Sending zero as ip tells probe_ops to free + * the probe->data itself + */ + if (probe_ops->free) + probe_ops->free(probe_ops, probe->tr, 0, probe->data); + list_del(&probe->list); + kfree(probe); + } +} + +static void acquire_probe_locked(struct ftrace_func_probe *probe) { - if (entry->ops->free) - entry->ops->free(entry->ops, entry->ip, &entry->data); - kfree(entry); + /* + * Add one ref to keep it from being freed when releasing the + * ftrace_lock mutex. + */ + probe->ref++; } int -register_ftrace_function_probe(char *glob, struct ftrace_probe_ops *ops, - void *data) +register_ftrace_function_probe(char *glob, struct trace_array *tr, + struct ftrace_probe_ops *probe_ops, + void *data) { - struct ftrace_func_probe *entry; - struct ftrace_hash **orig_hash = &trace_probe_ops.filter_hash; + struct ftrace_func_probe *probe = NULL, *iter; + struct ftrace_func_entry *entry; + struct ftrace_hash **orig_hash; + struct ftrace_hash *old_hash; struct ftrace_hash *hash; - struct ftrace_page *pg; - struct dyn_ftrace *rec; - int type, len, not; - unsigned long key; int count = 0; - char *search; + int size; int ret; + int i; - type = filter_parse_regex(glob, strlen(glob), &search, ¬); - len = strlen(search); + if (WARN_ON(!tr)) + return -EINVAL; - /* we do not support '!' for function probes */ - if (WARN_ON(not)) + /* We do not support '!' for function probes */ + if (WARN_ON(glob[0] == '!')) return -EINVAL; - mutex_lock(&trace_probe_ops.regex_lock); - hash = alloc_and_copy_ftrace_hash(FTRACE_HASH_DEFAULT_BITS, *orig_hash); - if (!hash) { - count = -ENOMEM; - goto out; + mutex_lock(&ftrace_lock); + /* Check if the probe_ops is already registered */ + list_for_each_entry(iter, &tr->func_probes, list) { + if (iter->probe_ops == probe_ops) { + probe = iter; + break; + } } - - if (unlikely(ftrace_disabled)) { - count = -ENODEV; - goto out; + if (!probe) { + probe = kzalloc(sizeof(*probe), GFP_KERNEL); + if (!probe) { + mutex_unlock(&ftrace_lock); + return -ENOMEM; + } + probe->probe_ops = probe_ops; + probe->ops.func = function_trace_probe_call; + probe->tr = tr; + ftrace_ops_init(&probe->ops); + list_add(&probe->list, &tr->func_probes); } - mutex_lock(&ftrace_lock); + acquire_probe_locked(probe); - do_for_each_ftrace_rec(pg, rec) { + mutex_unlock(&ftrace_lock); - if (!ftrace_match_record(rec, NULL, search, len, type)) - continue; + /* + * Note, there's a small window here that the func_hash->filter_hash + * may be NULL or empty. Need to be careful when reading the loop. + */ + mutex_lock(&probe->ops.func_hash->regex_lock); - entry = kmalloc(sizeof(*entry), GFP_KERNEL); - if (!entry) { - /* If we did not process any, then return error */ - if (!count) - count = -ENOMEM; - goto out_unlock; - } + orig_hash = &probe->ops.func_hash->filter_hash; + old_hash = *orig_hash; + hash = alloc_and_copy_ftrace_hash(FTRACE_HASH_DEFAULT_BITS, old_hash); - count++; + if (!hash) { + ret = -ENOMEM; + goto out; + } - entry->data = data; + ret = ftrace_match_records(hash, glob, strlen(glob)); - /* - * The caller might want to do something special - * for each function we find. We call the callback - * to give the caller an opportunity to do so. - */ - if (ops->init) { - if (ops->init(ops, rec->ip, &entry->data) < 0) { - /* caller does not like this func */ - kfree(entry); + /* Nothing found? */ + if (!ret) + ret = -EINVAL; + + if (ret < 0) + goto out; + + size = 1 << hash->size_bits; + for (i = 0; i < size; i++) { + hlist_for_each_entry(entry, &hash->buckets[i], hlist) { + if (ftrace_lookup_ip(old_hash, entry->ip)) continue; + /* + * The caller might want to do something special + * for each function we find. We call the callback + * to give the caller an opportunity to do so. + */ + if (probe_ops->init) { + ret = probe_ops->init(probe_ops, tr, + entry->ip, data, + &probe->data); + if (ret < 0) { + if (probe_ops->free && count) + probe_ops->free(probe_ops, tr, + 0, probe->data); + probe->data = NULL; + goto out; + } } + count++; } + } - ret = enter_record(hash, rec, 0); - if (ret < 0) { - kfree(entry); - count = ret; - goto out_unlock; - } - - entry->ops = ops; - entry->ip = rec->ip; - - key = hash_long(entry->ip, FTRACE_HASH_BITS); - hlist_add_head_rcu(&entry->node, &ftrace_func_hash[key]); + mutex_lock(&ftrace_lock); - } while_for_each_ftrace_rec(); + if (!count) { + /* Nothing was added? */ + ret = -EINVAL; + goto out_unlock; + } - ret = ftrace_hash_move(&trace_probe_ops, 1, orig_hash, hash); + ret = ftrace_hash_move_and_update_ops(&probe->ops, orig_hash, + hash, 1); if (ret < 0) - count = ret; + goto err_unlock; - __enable_ftrace_function_probe(); + /* One ref for each new function traced */ + probe->ref += count; + + if (!(probe->ops.flags & FTRACE_OPS_FL_ENABLED)) + ret = ftrace_startup(&probe->ops, 0); out_unlock: mutex_unlock(&ftrace_lock); + + if (!ret) + ret = count; out: - mutex_unlock(&trace_probe_ops.regex_lock); + mutex_unlock(&probe->ops.func_hash->regex_lock); free_ftrace_hash(hash); - return count; -} + release_probe(probe); -enum { - PROBE_TEST_FUNC = 1, - PROBE_TEST_DATA = 2 -}; + return ret; -static void -__unregister_ftrace_function_probe(char *glob, struct ftrace_probe_ops *ops, - void *data, int flags) -{ - struct ftrace_func_entry *rec_entry; - struct ftrace_func_probe *entry; - struct ftrace_func_probe *p; - struct ftrace_hash **orig_hash = &trace_probe_ops.filter_hash; - struct list_head free_list; - struct ftrace_hash *hash; + err_unlock: + if (!probe_ops->free || !count) + goto out_unlock; + + /* Failed to do the move, need to call the free functions */ + for (i = 0; i < size; i++) { + hlist_for_each_entry(entry, &hash->buckets[i], hlist) { + if (ftrace_lookup_ip(old_hash, entry->ip)) + continue; + probe_ops->free(probe_ops, tr, entry->ip, probe->data); + } + } + goto out_unlock; +} + +int +unregister_ftrace_function_probe_func(char *glob, struct trace_array *tr, + struct ftrace_probe_ops *probe_ops) +{ + struct ftrace_func_probe *probe = NULL, *iter; + struct ftrace_ops_hash old_hash_ops; + struct ftrace_func_entry *entry; + struct ftrace_glob func_g; + struct ftrace_hash **orig_hash; + struct ftrace_hash *old_hash; + struct ftrace_hash *hash = NULL; struct hlist_node *tmp; + struct hlist_head hhd; char str[KSYM_SYMBOL_LEN]; - int type = MATCH_FULL; - int i, len = 0; - char *search; + int count = 0; + int i, ret = -ENODEV; + int size; - if (glob && (strcmp(glob, "*") == 0 || !strlen(glob))) - glob = NULL; - else if (glob) { + if (!glob || !strlen(glob) || !strcmp(glob, "*")) + func_g.search = NULL; + else { int not; - type = filter_parse_regex(glob, strlen(glob), &search, ¬); - len = strlen(search); + func_g.type = filter_parse_regex(glob, strlen(glob), + &func_g.search, ¬); + func_g.len = strlen(func_g.search); /* we do not support '!' for function probes */ if (WARN_ON(not)) - return; + return -EINVAL; + } + + mutex_lock(&ftrace_lock); + /* Check if the probe_ops is already registered */ + list_for_each_entry(iter, &tr->func_probes, list) { + if (iter->probe_ops == probe_ops) { + probe = iter; + break; + } } + if (!probe) + goto err_unlock_ftrace; - mutex_lock(&trace_probe_ops.regex_lock); + ret = -EINVAL; + if (!(probe->ops.flags & FTRACE_OPS_FL_INITIALIZED)) + goto err_unlock_ftrace; - hash = alloc_and_copy_ftrace_hash(FTRACE_HASH_DEFAULT_BITS, *orig_hash); - if (!hash) - /* Hmm, should report this somehow */ - goto out_unlock; + acquire_probe_locked(probe); + + mutex_unlock(&ftrace_lock); - INIT_LIST_HEAD(&free_list); + mutex_lock(&probe->ops.func_hash->regex_lock); - for (i = 0; i < FTRACE_FUNC_HASHSIZE; i++) { - struct hlist_head *hhd = &ftrace_func_hash[i]; + orig_hash = &probe->ops.func_hash->filter_hash; + old_hash = *orig_hash; - hlist_for_each_entry_safe(entry, tmp, hhd, node) { + if (ftrace_hash_empty(old_hash)) + goto out_unlock; - /* break up if statements for readability */ - if ((flags & PROBE_TEST_FUNC) && entry->ops != ops) - continue; + old_hash_ops.filter_hash = old_hash; + /* Probes only have filters */ + old_hash_ops.notrace_hash = NULL; - if ((flags & PROBE_TEST_DATA) && entry->data != data) - continue; + ret = -ENOMEM; + hash = alloc_and_copy_ftrace_hash(FTRACE_HASH_DEFAULT_BITS, old_hash); + if (!hash) + goto out_unlock; + + INIT_HLIST_HEAD(&hhd); + + size = 1 << hash->size_bits; + for (i = 0; i < size; i++) { + hlist_for_each_entry_safe(entry, tmp, &hash->buckets[i], hlist) { - /* do this last, since it is the most expensive */ - if (glob) { + if (func_g.search) { kallsyms_lookup(entry->ip, NULL, NULL, NULL, str); - if (!ftrace_match(str, glob, len, type)) + if (!ftrace_match(str, &func_g)) continue; } - - rec_entry = ftrace_lookup_ip(hash, entry->ip); - /* It is possible more than one entry had this ip */ - if (rec_entry) - free_hash_entry(hash, rec_entry); - - hlist_del_rcu(&entry->node); - list_add(&entry->free_list, &free_list); + count++; + remove_hash_entry(hash, entry); + hlist_add_head(&entry->hlist, &hhd); } } + + /* Nothing found? */ + if (!count) { + ret = -EINVAL; + goto out_unlock; + } + mutex_lock(&ftrace_lock); - __disable_ftrace_function_probe(); - /* - * Remove after the disable is called. Otherwise, if the last - * probe is removed, a null hash means *all enabled*. - */ - ftrace_hash_move(&trace_probe_ops, 1, orig_hash, hash); - synchronize_sched(); - list_for_each_entry_safe(entry, p, &free_list, free_list) { - list_del(&entry->free_list); - ftrace_free_entry(entry); + + WARN_ON(probe->ref < count); + + probe->ref -= count; + + if (ftrace_hash_empty(hash)) + ftrace_shutdown(&probe->ops, 0); + + ret = ftrace_hash_move_and_update_ops(&probe->ops, orig_hash, + hash, 1); + + /* still need to update the function call sites */ + if (ftrace_enabled && !ftrace_hash_empty(hash)) + ftrace_run_modify_code(&probe->ops, FTRACE_UPDATE_CALLS, + &old_hash_ops); + synchronize_rcu(); + + hlist_for_each_entry_safe(entry, tmp, &hhd, hlist) { + hlist_del(&entry->hlist); + if (probe_ops->free) + probe_ops->free(probe_ops, tr, entry->ip, probe->data); + kfree(entry); } mutex_unlock(&ftrace_lock); - + out_unlock: - mutex_unlock(&trace_probe_ops.regex_lock); + mutex_unlock(&probe->ops.func_hash->regex_lock); free_ftrace_hash(hash); -} -void -unregister_ftrace_function_probe(char *glob, struct ftrace_probe_ops *ops, - void *data) -{ - __unregister_ftrace_function_probe(glob, ops, data, - PROBE_TEST_FUNC | PROBE_TEST_DATA); -} + release_probe(probe); -void -unregister_ftrace_function_probe_func(char *glob, struct ftrace_probe_ops *ops) -{ - __unregister_ftrace_function_probe(glob, ops, NULL, PROBE_TEST_FUNC); + return ret; + + err_unlock_ftrace: + mutex_unlock(&ftrace_lock); + return ret; } -void unregister_ftrace_function_probe_all(char *glob) +void clear_ftrace_function_probes(struct trace_array *tr) { - __unregister_ftrace_function_probe(glob, NULL, NULL, 0); + struct ftrace_func_probe *probe, *n; + + list_for_each_entry_safe(probe, n, &tr->func_probes, list) + unregister_ftrace_function_probe_func(NULL, tr, probe->probe_ops); } static LIST_HEAD(ftrace_commands); static DEFINE_MUTEX(ftrace_cmd_mutex); -int register_ftrace_command(struct ftrace_func_command *cmd) +/* + * Currently we only register ftrace commands from __init, so mark this + * __init too. + */ +__init int register_ftrace_command(struct ftrace_func_command *cmd) { struct ftrace_func_command *p; - int ret = 0; - mutex_lock(&ftrace_cmd_mutex); + guard(mutex)(&ftrace_cmd_mutex); list_for_each_entry(p, &ftrace_commands, list) { - if (strcmp(cmd->name, p->name) == 0) { - ret = -EBUSY; - goto out_unlock; - } + if (strcmp(cmd->name, p->name) == 0) + return -EBUSY; } list_add(&cmd->list, &ftrace_commands); - out_unlock: - mutex_unlock(&ftrace_cmd_mutex); - return ret; + return 0; } -int unregister_ftrace_command(struct ftrace_func_command *cmd) +/* + * Currently we only unregister ftrace commands from __init, so mark + * this __init too. + */ +__init int unregister_ftrace_command(struct ftrace_func_command *cmd) { struct ftrace_func_command *p, *n; - int ret = -ENODEV; - mutex_lock(&ftrace_cmd_mutex); + guard(mutex)(&ftrace_cmd_mutex); + list_for_each_entry_safe(p, n, &ftrace_commands, list) { if (strcmp(cmd->name, p->name) == 0) { - ret = 0; list_del_init(&p->list); - goto out_unlock; + return 0; } } - out_unlock: - mutex_unlock(&ftrace_cmd_mutex); - return ret; + return -ENODEV; } -static int ftrace_process_regex(struct ftrace_hash *hash, +static int ftrace_process_regex(struct ftrace_iterator *iter, char *buff, int len, int enable) { + struct ftrace_hash *hash = iter->hash; + struct trace_array *tr = iter->ops->private; char *func, *command, *next = buff; struct ftrace_func_command *p; - int ret = -EINVAL; + int ret; func = strsep(&next, ":"); @@ -3289,17 +5773,14 @@ static int ftrace_process_regex(struct ftrace_hash *hash, command = strsep(&next, ":"); - mutex_lock(&ftrace_cmd_mutex); + guard(mutex)(&ftrace_cmd_mutex); + list_for_each_entry(p, &ftrace_commands, list) { - if (strcmp(p->name, command) == 0) { - ret = p->func(hash, func, command, next, enable); - goto out_unlock; - } + if (strcmp(p->name, command) == 0) + return p->func(tr, hash, func, command, next, enable); } - out_unlock: - mutex_unlock(&ftrace_cmd_mutex); - return ret; + return -EINVAL; } static ssize_t @@ -3329,16 +5810,14 @@ ftrace_regex_write(struct file *file, const char __user *ubuf, if (read >= 0 && trace_parser_loaded(parser) && !trace_parser_cont(parser)) { - ret = ftrace_process_regex(iter->hash, parser->buffer, + ret = ftrace_process_regex(iter, parser->buffer, parser->idx, enable); trace_parser_clear(parser); if (ret < 0) - goto out; + return ret; } - ret = read; - out: - return ret; + return read; } ssize_t @@ -3356,11 +5835,12 @@ ftrace_notrace_write(struct file *file, const char __user *ubuf, } static int -ftrace_match_addr(struct ftrace_hash *hash, unsigned long ip, int remove) +__ftrace_match_addr(struct ftrace_hash *hash, unsigned long ip, int remove) { struct ftrace_func_entry *entry; - if (!ftrace_location(ip)) + ip = ftrace_location(ip); + if (!ip) return -EINVAL; if (remove) { @@ -3369,107 +5849,555 @@ ftrace_match_addr(struct ftrace_hash *hash, unsigned long ip, int remove) return -ENOENT; free_hash_entry(hash, entry); return 0; + } else if (__ftrace_lookup_ip(hash, ip) != NULL) { + /* Already exists */ + return 0; } - return add_hash_entry(hash, ip); + entry = add_hash_entry(hash, ip); + return entry ? 0 : -ENOMEM; +} + +static int +ftrace_match_addr(struct ftrace_hash *hash, unsigned long *ips, + unsigned int cnt, int remove) +{ + unsigned int i; + int err; + + for (i = 0; i < cnt; i++) { + err = __ftrace_match_addr(hash, ips[i], remove); + if (err) { + /* + * This expects the @hash is a temporary hash and if this + * fails the caller must free the @hash. + */ + return err; + } + } + return 0; } static int ftrace_set_hash(struct ftrace_ops *ops, unsigned char *buf, int len, - unsigned long ip, int remove, int reset, int enable) + unsigned long *ips, unsigned int cnt, + int remove, int reset, int enable, char *mod) { struct ftrace_hash **orig_hash; struct ftrace_hash *hash; int ret; - /* All global ops uses the global ops filters */ - if (ops->flags & FTRACE_OPS_FL_GLOBAL) - ops = &global_ops; - if (unlikely(ftrace_disabled)) return -ENODEV; - mutex_lock(&ops->regex_lock); + mutex_lock(&ops->func_hash->regex_lock); if (enable) - orig_hash = &ops->filter_hash; + orig_hash = &ops->func_hash->filter_hash; + else + orig_hash = &ops->func_hash->notrace_hash; + + if (reset) + hash = alloc_ftrace_hash(FTRACE_HASH_DEFAULT_BITS); else - orig_hash = &ops->notrace_hash; + hash = alloc_and_copy_ftrace_hash(FTRACE_HASH_DEFAULT_BITS, *orig_hash); - hash = alloc_and_copy_ftrace_hash(FTRACE_HASH_DEFAULT_BITS, *orig_hash); if (!hash) { ret = -ENOMEM; goto out_regex_unlock; } - if (reset) - ftrace_filter_reset(hash); - if (buf && !ftrace_match_records(hash, buf, len)) { + if (buf && !match_records(hash, buf, len, mod)) { + /* If this was for a module and nothing was enabled, flag it */ + if (mod) + (*orig_hash)->flags |= FTRACE_HASH_FL_MOD; + + /* + * Even if it is a mod, return error to let caller know + * nothing was added + */ ret = -EINVAL; goto out_regex_unlock; } - if (ip) { - ret = ftrace_match_addr(hash, ip, remove); + if (ips) { + ret = ftrace_match_addr(hash, ips, cnt, remove); if (ret < 0) goto out_regex_unlock; } mutex_lock(&ftrace_lock); - ret = ftrace_hash_move(ops, enable, orig_hash, hash); - if (!ret && ops->flags & FTRACE_OPS_FL_ENABLED - && ftrace_enabled) - ftrace_run_update_code(FTRACE_UPDATE_CALLS); - + ret = ftrace_hash_move_and_update_ops(ops, orig_hash, hash, enable); mutex_unlock(&ftrace_lock); out_regex_unlock: - mutex_unlock(&ops->regex_lock); + mutex_unlock(&ops->func_hash->regex_lock); free_ftrace_hash(hash); return ret; } static int -ftrace_set_addr(struct ftrace_ops *ops, unsigned long ip, int remove, - int reset, int enable) +ftrace_set_addr(struct ftrace_ops *ops, unsigned long *ips, unsigned int cnt, + int remove, int reset, int enable) { - return ftrace_set_hash(ops, 0, 0, ip, remove, reset, enable); + return ftrace_set_hash(ops, NULL, 0, ips, cnt, remove, reset, enable, NULL); } +#ifdef CONFIG_DYNAMIC_FTRACE_WITH_DIRECT_CALLS + +static int register_ftrace_function_nolock(struct ftrace_ops *ops); + +/* + * If there are multiple ftrace_ops, use SAVE_REGS by default, so that direct + * call will be jumped from ftrace_regs_caller. Only if the architecture does + * not support ftrace_regs_caller but direct_call, use SAVE_ARGS so that it + * jumps from ftrace_caller for multiple ftrace_ops. + */ +#ifndef CONFIG_HAVE_DYNAMIC_FTRACE_WITH_REGS +#define MULTI_FLAGS (FTRACE_OPS_FL_DIRECT | FTRACE_OPS_FL_SAVE_ARGS) +#else +#define MULTI_FLAGS (FTRACE_OPS_FL_DIRECT | FTRACE_OPS_FL_SAVE_REGS) +#endif + +static int check_direct_multi(struct ftrace_ops *ops) +{ + if (!(ops->flags & FTRACE_OPS_FL_INITIALIZED)) + return -EINVAL; + if ((ops->flags & MULTI_FLAGS) != MULTI_FLAGS) + return -EINVAL; + return 0; +} + +static void remove_direct_functions_hash(struct ftrace_hash *hash, unsigned long addr) +{ + struct ftrace_func_entry *entry, *del; + int size, i; + + size = 1 << hash->size_bits; + for (i = 0; i < size; i++) { + hlist_for_each_entry(entry, &hash->buckets[i], hlist) { + del = __ftrace_lookup_ip(direct_functions, entry->ip); + if (del && ftrace_jmp_get(del->direct) == + ftrace_jmp_get(addr)) { + remove_hash_entry(direct_functions, del); + kfree(del); + } + } + } +} + +static void register_ftrace_direct_cb(struct rcu_head *rhp) +{ + struct ftrace_hash *fhp = container_of(rhp, struct ftrace_hash, rcu); + + free_ftrace_hash(fhp); +} + +static void reset_direct(struct ftrace_ops *ops, unsigned long addr) +{ + struct ftrace_hash *hash = ops->func_hash->filter_hash; + + remove_direct_functions_hash(hash, addr); + + /* cleanup for possible another register call */ + ops->func = NULL; + ops->trampoline = 0; +} + +/** + * register_ftrace_direct - Call a custom trampoline directly + * for multiple functions registered in @ops + * @ops: The address of the struct ftrace_ops object + * @addr: The address of the trampoline to call at @ops functions + * + * This is used to connect a direct calls to @addr from the nop locations + * of the functions registered in @ops (with by ftrace_set_filter_ip + * function). + * + * The location that it calls (@addr) must be able to handle a direct call, + * and save the parameters of the function being traced, and restore them + * (or inject new ones if needed), before returning. + * + * Returns: + * 0 on success + * -EINVAL - The @ops object was already registered with this call or + * when there are no functions in @ops object. + * -EBUSY - Another direct function is already attached (there can be only one) + * -ENODEV - @ip does not point to a ftrace nop location (or not supported) + * -ENOMEM - There was an allocation failure. + */ +int register_ftrace_direct(struct ftrace_ops *ops, unsigned long addr) +{ + struct ftrace_hash *hash, *new_hash = NULL, *free_hash = NULL; + struct ftrace_func_entry *entry, *new; + int err = -EBUSY, size, i; + + if (ops->func || ops->trampoline) + return -EINVAL; + if (!(ops->flags & FTRACE_OPS_FL_INITIALIZED)) + return -EINVAL; + if (ops->flags & FTRACE_OPS_FL_ENABLED) + return -EINVAL; + + hash = ops->func_hash->filter_hash; + if (ftrace_hash_empty(hash)) + return -EINVAL; + + /* This is a "raw" address, and this should never happen. */ + if (WARN_ON_ONCE(ftrace_is_jmp(addr))) + return -EINVAL; + + mutex_lock(&direct_mutex); + + if (ops->flags & FTRACE_OPS_FL_JMP) + addr = ftrace_jmp_set(addr); + + /* Make sure requested entries are not already registered.. */ + size = 1 << hash->size_bits; + for (i = 0; i < size; i++) { + hlist_for_each_entry(entry, &hash->buckets[i], hlist) { + if (ftrace_find_rec_direct(entry->ip)) + goto out_unlock; + } + } + + err = -ENOMEM; + + /* Make a copy hash to place the new and the old entries in */ + size = hash->count + direct_functions->count; + size = fls(size); + if (size > FTRACE_HASH_MAX_BITS) + size = FTRACE_HASH_MAX_BITS; + new_hash = alloc_ftrace_hash(size); + if (!new_hash) + goto out_unlock; + + /* Now copy over the existing direct entries */ + size = 1 << direct_functions->size_bits; + for (i = 0; i < size; i++) { + hlist_for_each_entry(entry, &direct_functions->buckets[i], hlist) { + new = add_hash_entry(new_hash, entry->ip); + if (!new) + goto out_unlock; + new->direct = entry->direct; + } + } + + /* ... and add the new entries */ + size = 1 << hash->size_bits; + for (i = 0; i < size; i++) { + hlist_for_each_entry(entry, &hash->buckets[i], hlist) { + new = add_hash_entry(new_hash, entry->ip); + if (!new) + goto out_unlock; + /* Update both the copy and the hash entry */ + new->direct = addr; + entry->direct = addr; + } + } + + free_hash = direct_functions; + rcu_assign_pointer(direct_functions, new_hash); + new_hash = NULL; + + ops->func = call_direct_funcs; + ops->flags |= MULTI_FLAGS; + ops->trampoline = FTRACE_REGS_ADDR; + ops->direct_call = addr; + + err = register_ftrace_function_nolock(ops); + if (err) + reset_direct(ops, addr); + + out_unlock: + mutex_unlock(&direct_mutex); + + if (free_hash && free_hash != EMPTY_HASH) + call_rcu_tasks(&free_hash->rcu, register_ftrace_direct_cb); + + if (new_hash) + free_ftrace_hash(new_hash); + + return err; +} +EXPORT_SYMBOL_GPL(register_ftrace_direct); + +/** + * unregister_ftrace_direct - Remove calls to custom trampoline + * previously registered by register_ftrace_direct for @ops object. + * @ops: The address of the struct ftrace_ops object + * @addr: The address of the direct function that is called by the @ops functions + * @free_filters: Set to true to remove all filters for the ftrace_ops, false otherwise + * + * This is used to remove a direct calls to @addr from the nop locations + * of the functions registered in @ops (with by ftrace_set_filter_ip + * function). + * + * Returns: + * 0 on success + * -EINVAL - The @ops object was not properly registered. + */ +int unregister_ftrace_direct(struct ftrace_ops *ops, unsigned long addr, + bool free_filters) +{ + int err; + + if (check_direct_multi(ops)) + return -EINVAL; + if (!(ops->flags & FTRACE_OPS_FL_ENABLED)) + return -EINVAL; + + mutex_lock(&direct_mutex); + err = unregister_ftrace_function(ops); + reset_direct(ops, addr); + mutex_unlock(&direct_mutex); + + if (free_filters) + ftrace_free_filter(ops); + return err; +} +EXPORT_SYMBOL_GPL(unregister_ftrace_direct); + +static int +__modify_ftrace_direct(struct ftrace_ops *ops, unsigned long addr) +{ + struct ftrace_hash *hash = ops->func_hash->filter_hash; + struct ftrace_func_entry *entry, *iter; + static struct ftrace_ops tmp_ops = { + .func = ftrace_stub, + .flags = FTRACE_OPS_FL_STUB, + }; + int i, size; + int err; + + lockdep_assert_held_once(&direct_mutex); + + /* This is a "raw" address, and this should never happen. */ + if (WARN_ON_ONCE(ftrace_is_jmp(addr))) + return -EINVAL; + + if (ops->flags & FTRACE_OPS_FL_JMP) + addr = ftrace_jmp_set(addr); + + /* Enable the tmp_ops to have the same functions as the direct ops */ + ftrace_ops_init(&tmp_ops); + tmp_ops.func_hash = ops->func_hash; + tmp_ops.direct_call = addr; + + err = register_ftrace_function_nolock(&tmp_ops); + if (err) + return err; + + /* + * Call __ftrace_hash_update_ipmodify() here, so that we can call + * ops->ops_func for the ops. This is needed because the above + * register_ftrace_function_nolock() worked on tmp_ops. + */ + err = __ftrace_hash_update_ipmodify(ops, hash, hash, true); + if (err) + goto out; + + /* + * Now the ftrace_ops_list_func() is called to do the direct callers. + * We can safely change the direct functions attached to each entry. + */ + mutex_lock(&ftrace_lock); + + size = 1 << hash->size_bits; + for (i = 0; i < size; i++) { + hlist_for_each_entry(iter, &hash->buckets[i], hlist) { + entry = __ftrace_lookup_ip(direct_functions, iter->ip); + if (!entry) + continue; + entry->direct = addr; + } + } + /* Prevent store tearing if a trampoline concurrently accesses the value */ + WRITE_ONCE(ops->direct_call, addr); + + mutex_unlock(&ftrace_lock); + +out: + /* Removing the tmp_ops will add the updated direct callers to the functions */ + unregister_ftrace_function(&tmp_ops); + + return err; +} + +/** + * modify_ftrace_direct_nolock - Modify an existing direct 'multi' call + * to call something else + * @ops: The address of the struct ftrace_ops object + * @addr: The address of the new trampoline to call at @ops functions + * + * This is used to unregister currently registered direct caller and + * register new one @addr on functions registered in @ops object. + * + * Note there's window between ftrace_shutdown and ftrace_startup calls + * where there will be no callbacks called. + * + * Caller should already have direct_mutex locked, so we don't lock + * direct_mutex here. + * + * Returns: zero on success. Non zero on error, which includes: + * -EINVAL - The @ops object was not properly registered. + */ +int modify_ftrace_direct_nolock(struct ftrace_ops *ops, unsigned long addr) +{ + if (check_direct_multi(ops)) + return -EINVAL; + if (!(ops->flags & FTRACE_OPS_FL_ENABLED)) + return -EINVAL; + + return __modify_ftrace_direct(ops, addr); +} +EXPORT_SYMBOL_GPL(modify_ftrace_direct_nolock); + +/** + * modify_ftrace_direct - Modify an existing direct 'multi' call + * to call something else + * @ops: The address of the struct ftrace_ops object + * @addr: The address of the new trampoline to call at @ops functions + * + * This is used to unregister currently registered direct caller and + * register new one @addr on functions registered in @ops object. + * + * Note there's window between ftrace_shutdown and ftrace_startup calls + * where there will be no callbacks called. + * + * Returns: zero on success. Non zero on error, which includes: + * -EINVAL - The @ops object was not properly registered. + */ +int modify_ftrace_direct(struct ftrace_ops *ops, unsigned long addr) +{ + int err; + + if (check_direct_multi(ops)) + return -EINVAL; + if (!(ops->flags & FTRACE_OPS_FL_ENABLED)) + return -EINVAL; + + mutex_lock(&direct_mutex); + err = __modify_ftrace_direct(ops, addr); + mutex_unlock(&direct_mutex); + return err; +} +EXPORT_SYMBOL_GPL(modify_ftrace_direct); +#endif /* CONFIG_DYNAMIC_FTRACE_WITH_DIRECT_CALLS */ + /** * ftrace_set_filter_ip - set a function to filter on in ftrace by address - * @ops - the ops to set the filter with - * @ip - the address to add to or remove from the filter. - * @remove - non zero to remove the ip from the filter - * @reset - non zero to reset all filters before applying this filter. + * @ops: the ops to set the filter with + * @ip: the address to add to or remove from the filter. + * @remove: non zero to remove the ip from the filter + * @reset: non zero to reset all filters before applying this filter. * * Filters denote which functions should be enabled when tracing is enabled - * If @ip is NULL, it failes to update filter. + * If @ip is NULL, it fails to update filter. + * + * This can allocate memory which must be freed before @ops can be freed, + * either by removing each filtered addr or by using + * ftrace_free_filter(@ops). */ int ftrace_set_filter_ip(struct ftrace_ops *ops, unsigned long ip, int remove, int reset) { ftrace_ops_init(ops); - return ftrace_set_addr(ops, ip, remove, reset, 1); + return ftrace_set_addr(ops, &ip, 1, remove, reset, 1); } EXPORT_SYMBOL_GPL(ftrace_set_filter_ip); +/** + * ftrace_set_filter_ips - set functions to filter on in ftrace by addresses + * @ops: the ops to set the filter with + * @ips: the array of addresses to add to or remove from the filter. + * @cnt: the number of addresses in @ips + * @remove: non zero to remove ips from the filter + * @reset: non zero to reset all filters before applying this filter. + * + * Filters denote which functions should be enabled when tracing is enabled + * If @ips array or any ip specified within is NULL , it fails to update filter. + * + * This can allocate memory which must be freed before @ops can be freed, + * either by removing each filtered addr or by using + * ftrace_free_filter(@ops). +*/ +int ftrace_set_filter_ips(struct ftrace_ops *ops, unsigned long *ips, + unsigned int cnt, int remove, int reset) +{ + ftrace_ops_init(ops); + return ftrace_set_addr(ops, ips, cnt, remove, reset, 1); +} +EXPORT_SYMBOL_GPL(ftrace_set_filter_ips); + +/** + * ftrace_ops_set_global_filter - setup ops to use global filters + * @ops: the ops which will use the global filters + * + * ftrace users who need global function trace filtering should call this. + * It can set the global filter only if ops were not initialized before. + */ +void ftrace_ops_set_global_filter(struct ftrace_ops *ops) +{ + if (ops->flags & FTRACE_OPS_FL_INITIALIZED) + return; + + ftrace_ops_init(ops); + ops->func_hash = &global_ops.local_hash; +} +EXPORT_SYMBOL_GPL(ftrace_ops_set_global_filter); + static int ftrace_set_regex(struct ftrace_ops *ops, unsigned char *buf, int len, int reset, int enable) { - return ftrace_set_hash(ops, buf, len, 0, 0, reset, enable); + char *mod = NULL, *func, *command, *next = buf; + char *tmp __free(kfree) = NULL; + struct trace_array *tr = ops->private; + int ret; + + func = strsep(&next, ":"); + + /* This can also handle :mod: parsing */ + if (next) { + if (!tr) + return -EINVAL; + + command = strsep(&next, ":"); + if (strcmp(command, "mod") != 0) + return -EINVAL; + + mod = next; + len = command - func; + /* Save the original func as ftrace_set_hash() can modify it */ + tmp = kstrdup(func, GFP_KERNEL); + } + + ret = ftrace_set_hash(ops, func, len, NULL, 0, 0, reset, enable, mod); + + if (tr && mod && ret < 0) { + /* Did tmp fail to allocate? */ + if (!tmp) + return -ENOMEM; + ret = cache_mod(tr, tmp, mod, enable); + } + + return ret; } /** * ftrace_set_filter - set a function to filter on in ftrace - * @ops - the ops to set the filter with - * @buf - the string that holds the function filter text. - * @len - the length of the string. - * @reset - non zero to reset all filters before applying this filter. + * @ops: the ops to set the filter with + * @buf: the string that holds the function filter text. + * @len: the length of the string. + * @reset: non-zero to reset all filters before applying this filter. * * Filters denote which functions should be enabled when tracing is enabled. * If @buf is NULL and reset is set, all functions will be enabled for tracing. + * + * This can allocate memory which must be freed before @ops can be freed, + * either by removing each filtered addr or by using + * ftrace_free_filter(@ops). */ int ftrace_set_filter(struct ftrace_ops *ops, unsigned char *buf, int len, int reset) @@ -3481,14 +6409,18 @@ EXPORT_SYMBOL_GPL(ftrace_set_filter); /** * ftrace_set_notrace - set a function to not trace in ftrace - * @ops - the ops to set the notrace filter with - * @buf - the string that holds the function notrace text. - * @len - the length of the string. - * @reset - non zero to reset all filters before applying this filter. + * @ops: the ops to set the notrace filter with + * @buf: the string that holds the function notrace text. + * @len: the length of the string. + * @reset: non-zero to reset all filters before applying this filter. * * Notrace Filters denote which functions should not be enabled when tracing * is enabled. If @buf is NULL and reset is set, all functions will be enabled * for tracing. + * + * This can allocate memory which must be freed before @ops can be freed, + * either by removing each filtered addr or by using + * ftrace_free_filter(@ops). */ int ftrace_set_notrace(struct ftrace_ops *ops, unsigned char *buf, int len, int reset) @@ -3498,11 +6430,10 @@ int ftrace_set_notrace(struct ftrace_ops *ops, unsigned char *buf, } EXPORT_SYMBOL_GPL(ftrace_set_notrace); /** - * ftrace_set_filter - set a function to filter on in ftrace - * @ops - the ops to set the filter with - * @buf - the string that holds the function filter text. - * @len - the length of the string. - * @reset - non zero to reset all filters before applying this filter. + * ftrace_set_global_filter - set a function to filter on with global tracers + * @buf: the string that holds the function filter text. + * @len: the length of the string. + * @reset: non-zero to reset all filters before applying this filter. * * Filters denote which functions should be enabled when tracing is enabled. * If @buf is NULL and reset is set, all functions will be enabled for tracing. @@ -3514,11 +6445,10 @@ void ftrace_set_global_filter(unsigned char *buf, int len, int reset) EXPORT_SYMBOL_GPL(ftrace_set_global_filter); /** - * ftrace_set_notrace - set a function to not trace in ftrace - * @ops - the ops to set the notrace filter with - * @buf - the string that holds the function notrace text. - * @len - the length of the string. - * @reset - non zero to reset all filters before applying this filter. + * ftrace_set_global_notrace - set a function to not trace with global tracers + * @buf: the string that holds the function notrace text. + * @len: the length of the string. + * @reset: non-zero to reset all filters before applying this filter. * * Notrace Filters denote which functions should not be enabled when tracing * is enabled. If @buf is NULL and reset is set, all functions will be enabled @@ -3543,7 +6473,7 @@ bool ftrace_filter_param __initdata; static int __init set_ftrace_notrace(char *str) { ftrace_filter_param = true; - strlcpy(ftrace_notrace_buf, str, FTRACE_FILTER_SIZE); + strscpy(ftrace_notrace_buf, str, FTRACE_FILTER_SIZE); return 1; } __setup("ftrace_notrace=", set_ftrace_notrace); @@ -3551,36 +6481,61 @@ __setup("ftrace_notrace=", set_ftrace_notrace); static int __init set_ftrace_filter(char *str) { ftrace_filter_param = true; - strlcpy(ftrace_filter_buf, str, FTRACE_FILTER_SIZE); + strscpy(ftrace_filter_buf, str, FTRACE_FILTER_SIZE); return 1; } __setup("ftrace_filter=", set_ftrace_filter); #ifdef CONFIG_FUNCTION_GRAPH_TRACER static char ftrace_graph_buf[FTRACE_FILTER_SIZE] __initdata; -static int ftrace_set_func(unsigned long *array, int *idx, char *buffer); +static char ftrace_graph_notrace_buf[FTRACE_FILTER_SIZE] __initdata; +static int ftrace_graph_set_hash(struct ftrace_hash *hash, char *buffer); static int __init set_graph_function(char *str) { - strlcpy(ftrace_graph_buf, str, FTRACE_FILTER_SIZE); + strscpy(ftrace_graph_buf, str, FTRACE_FILTER_SIZE); return 1; } __setup("ftrace_graph_filter=", set_graph_function); -static void __init set_ftrace_early_graph(char *buf) +static int __init set_graph_notrace_function(char *str) +{ + strscpy(ftrace_graph_notrace_buf, str, FTRACE_FILTER_SIZE); + return 1; +} +__setup("ftrace_graph_notrace=", set_graph_notrace_function); + +static int __init set_graph_max_depth_function(char *str) +{ + if (!str || kstrtouint(str, 0, &fgraph_max_depth)) + return 0; + return 1; +} +__setup("ftrace_graph_max_depth=", set_graph_max_depth_function); + +static void __init set_ftrace_early_graph(char *buf, int enable) { int ret; char *func; + struct ftrace_hash *hash; + + hash = alloc_ftrace_hash(FTRACE_HASH_DEFAULT_BITS); + if (MEM_FAIL(!hash, "Failed to allocate hash\n")) + return; while (buf) { func = strsep(&buf, ","); /* we allow only one expression at a time */ - ret = ftrace_set_func(ftrace_graph_funcs, &ftrace_graph_count, - func); + ret = ftrace_graph_set_hash(hash, func); if (ret) printk(KERN_DEBUG "ftrace: function %s not " "traceable\n", func); } + + if (enable) + ftrace_graph_hash = hash; + else + ftrace_graph_notrace_hash = hash; } #endif /* CONFIG_FUNCTION_GRAPH_TRACER */ @@ -3591,6 +6546,14 @@ ftrace_set_early_filter(struct ftrace_ops *ops, char *buf, int enable) ftrace_ops_init(ops); + /* The trace_array is needed for caching module function filters */ + if (!ops->private) { + struct trace_array *tr = trace_get_global_array(); + + ops->private = tr; + ftrace_init_trace_array(tr); + } + while (buf) { func = strsep(&buf, ","); ftrace_set_regex(ops, func, strlen(func), 0, enable); @@ -3605,7 +6568,9 @@ static void __init set_ftrace_early_filters(void) ftrace_set_early_filter(&global_ops, ftrace_notrace_buf, 0); #ifdef CONFIG_FUNCTION_GRAPH_TRACER if (ftrace_graph_buf[0]) - set_ftrace_early_graph(ftrace_graph_buf); + set_ftrace_early_graph(ftrace_graph_buf, 1); + if (ftrace_graph_notrace_buf[0]) + set_ftrace_early_graph(ftrace_graph_notrace_buf, 0); #endif /* CONFIG_FUNCTION_GRAPH_TRACER */ } @@ -3616,7 +6581,6 @@ int ftrace_regex_release(struct inode *inode, struct file *file) struct ftrace_hash **orig_hash; struct trace_parser *parser; int filter_hash; - int ret; if (file->f_mode & FMODE_READ) { iter = m->private; @@ -3626,34 +6590,40 @@ int ftrace_regex_release(struct inode *inode, struct file *file) parser = &iter->parser; if (trace_parser_loaded(parser)) { - parser->buffer[parser->idx] = 0; - ftrace_match_records(iter->hash, parser->buffer, parser->idx); + int enable = !(iter->flags & FTRACE_ITER_NOTRACE); + + ftrace_process_regex(iter, parser->buffer, + parser->idx, enable); } trace_parser_put(parser); - mutex_lock(&iter->ops->regex_lock); + mutex_lock(&iter->ops->func_hash->regex_lock); if (file->f_mode & FMODE_WRITE) { filter_hash = !!(iter->flags & FTRACE_ITER_FILTER); - if (filter_hash) - orig_hash = &iter->ops->filter_hash; - else - orig_hash = &iter->ops->notrace_hash; + if (filter_hash) { + orig_hash = &iter->ops->func_hash->filter_hash; + if (iter->tr) { + if (list_empty(&iter->tr->mod_trace)) + iter->hash->flags &= ~FTRACE_HASH_FL_MOD; + else + iter->hash->flags |= FTRACE_HASH_FL_MOD; + } + } else + orig_hash = &iter->ops->func_hash->notrace_hash; mutex_lock(&ftrace_lock); - ret = ftrace_hash_move(iter->ops, filter_hash, - orig_hash, iter->hash); - if (!ret && (iter->ops->flags & FTRACE_OPS_FL_ENABLED) - && ftrace_enabled) - ftrace_run_update_code(FTRACE_UPDATE_CALLS); - + ftrace_hash_move_and_update_ops(iter->ops, orig_hash, + iter->hash, filter_hash); mutex_unlock(&ftrace_lock); } - mutex_unlock(&iter->ops->regex_lock); + mutex_unlock(&iter->ops->func_hash->regex_lock); free_ftrace_hash(iter->hash); + if (iter->tr) + trace_array_put(iter->tr); kfree(iter); return 0; @@ -3673,11 +6643,25 @@ static const struct file_operations ftrace_enabled_fops = { .release = seq_release_private, }; +static const struct file_operations ftrace_touched_fops = { + .open = ftrace_touched_open, + .read = seq_read, + .llseek = seq_lseek, + .release = seq_release_private, +}; + +static const struct file_operations ftrace_avail_addrs_fops = { + .open = ftrace_avail_addrs_open, + .read = seq_read, + .llseek = seq_lseek, + .release = seq_release_private, +}; + static const struct file_operations ftrace_filter_fops = { .open = ftrace_filter_open, .read = seq_read, .write = ftrace_filter_write, - .llseek = ftrace_filter_lseek, + .llseek = tracing_lseek, .release = ftrace_regex_release, }; @@ -3685,7 +6669,7 @@ static const struct file_operations ftrace_notrace_fops = { .open = ftrace_notrace_open, .read = seq_read, .write = ftrace_notrace_write, - .llseek = ftrace_filter_lseek, + .llseek = tracing_lseek, .release = ftrace_regex_release, }; @@ -3693,16 +6677,55 @@ static const struct file_operations ftrace_notrace_fops = { static DEFINE_MUTEX(graph_lock); -int ftrace_graph_count; -int ftrace_graph_filter_enabled; -unsigned long ftrace_graph_funcs[FTRACE_GRAPH_MAX_FUNCS] __read_mostly; +struct ftrace_hash __rcu *ftrace_graph_hash = EMPTY_HASH; +struct ftrace_hash __rcu *ftrace_graph_notrace_hash = EMPTY_HASH; + +enum graph_filter_type { + GRAPH_FILTER_NOTRACE = 0, + GRAPH_FILTER_FUNCTION, +}; + +#define FTRACE_GRAPH_EMPTY ((void *)1) + +struct ftrace_graph_data { + struct ftrace_hash *hash; + struct ftrace_func_entry *entry; + int idx; /* for hash table iteration */ + enum graph_filter_type type; + struct ftrace_hash *new_hash; + const struct seq_operations *seq_ops; + struct trace_parser parser; +}; static void * __g_next(struct seq_file *m, loff_t *pos) { - if (*pos >= ftrace_graph_count) + struct ftrace_graph_data *fgd = m->private; + struct ftrace_func_entry *entry = fgd->entry; + struct hlist_head *head; + int i, idx = fgd->idx; + + if (*pos >= fgd->hash->count) return NULL; - return &ftrace_graph_funcs[*pos]; + + if (entry) { + hlist_for_each_entry_continue(entry, hlist) { + fgd->entry = entry; + return entry; + } + + idx++; + } + + for (i = idx; i < 1 << fgd->hash->size_bits; i++) { + head = &fgd->hash->buckets[i]; + hlist_for_each_entry(entry, head, hlist) { + fgd->entry = entry; + fgd->idx = i; + return entry; + } + } + return NULL; } static void * @@ -3714,12 +6737,23 @@ g_next(struct seq_file *m, void *v, loff_t *pos) static void *g_start(struct seq_file *m, loff_t *pos) { + struct ftrace_graph_data *fgd = m->private; + mutex_lock(&graph_lock); + if (fgd->type == GRAPH_FILTER_FUNCTION) + fgd->hash = rcu_dereference_protected(ftrace_graph_hash, + lockdep_is_held(&graph_lock)); + else + fgd->hash = rcu_dereference_protected(ftrace_graph_notrace_hash, + lockdep_is_held(&graph_lock)); + /* Nothing, tell g_show to print all functions are enabled */ - if (!ftrace_graph_filter_enabled && !*pos) - return (void *)1; + if (ftrace_hash_empty(fgd->hash) && !*pos) + return FTRACE_GRAPH_EMPTY; + fgd->idx = 0; + fgd->entry = NULL; return __g_next(m, pos); } @@ -3730,17 +6764,22 @@ static void g_stop(struct seq_file *m, void *p) static int g_show(struct seq_file *m, void *v) { - unsigned long *ptr = v; + struct ftrace_func_entry *entry = v; - if (!ptr) + if (!entry) return 0; - if (ptr == (unsigned long *)1) { - seq_printf(m, "#### all functions enabled ####\n"); + if (entry == FTRACE_GRAPH_EMPTY) { + struct ftrace_graph_data *fgd = m->private; + + if (fgd->type == GRAPH_FILTER_FUNCTION) + seq_puts(m, "#### all functions enabled ####\n"); + else + seq_puts(m, "#### no functions disabled ####\n"); return 0; } - seq_printf(m, "%ps\n", (void *)*ptr); + seq_printf(m, "%ps\n", (void *)entry->ip); return 0; } @@ -3753,136 +6792,268 @@ static const struct seq_operations ftrace_graph_seq_ops = { }; static int +__ftrace_graph_open(struct inode *inode, struct file *file, + struct ftrace_graph_data *fgd) +{ + int ret; + struct ftrace_hash *new_hash = NULL; + + ret = security_locked_down(LOCKDOWN_TRACEFS); + if (ret) + return ret; + + if (file->f_mode & FMODE_WRITE) { + const int size_bits = FTRACE_HASH_DEFAULT_BITS; + + if (trace_parser_get_init(&fgd->parser, FTRACE_BUFF_MAX)) + return -ENOMEM; + + if (file->f_flags & O_TRUNC) + new_hash = alloc_ftrace_hash(size_bits); + else + new_hash = alloc_and_copy_ftrace_hash(size_bits, + fgd->hash); + if (!new_hash) { + ret = -ENOMEM; + goto out; + } + } + + if (file->f_mode & FMODE_READ) { + ret = seq_open(file, &ftrace_graph_seq_ops); + if (!ret) { + struct seq_file *m = file->private_data; + m->private = fgd; + } else { + /* Failed */ + free_ftrace_hash(new_hash); + new_hash = NULL; + } + } else + file->private_data = fgd; + +out: + if (ret < 0 && file->f_mode & FMODE_WRITE) + trace_parser_put(&fgd->parser); + + fgd->new_hash = new_hash; + + /* + * All uses of fgd->hash must be taken with the graph_lock + * held. The graph_lock is going to be released, so force + * fgd->hash to be reinitialized when it is taken again. + */ + fgd->hash = NULL; + + return ret; +} + +static int ftrace_graph_open(struct inode *inode, struct file *file) { - int ret = 0; + struct ftrace_graph_data *fgd; + int ret; if (unlikely(ftrace_disabled)) return -ENODEV; + fgd = kmalloc(sizeof(*fgd), GFP_KERNEL); + if (fgd == NULL) + return -ENOMEM; + mutex_lock(&graph_lock); - if ((file->f_mode & FMODE_WRITE) && - (file->f_flags & O_TRUNC)) { - ftrace_graph_filter_enabled = 0; - ftrace_graph_count = 0; - memset(ftrace_graph_funcs, 0, sizeof(ftrace_graph_funcs)); - } + + fgd->hash = rcu_dereference_protected(ftrace_graph_hash, + lockdep_is_held(&graph_lock)); + fgd->type = GRAPH_FILTER_FUNCTION; + fgd->seq_ops = &ftrace_graph_seq_ops; + + ret = __ftrace_graph_open(inode, file, fgd); + if (ret < 0) + kfree(fgd); + mutex_unlock(&graph_lock); + return ret; +} - if (file->f_mode & FMODE_READ) - ret = seq_open(file, &ftrace_graph_seq_ops); +static int +ftrace_graph_notrace_open(struct inode *inode, struct file *file) +{ + struct ftrace_graph_data *fgd; + int ret; + + if (unlikely(ftrace_disabled)) + return -ENODEV; + + fgd = kmalloc(sizeof(*fgd), GFP_KERNEL); + if (fgd == NULL) + return -ENOMEM; + mutex_lock(&graph_lock); + + fgd->hash = rcu_dereference_protected(ftrace_graph_notrace_hash, + lockdep_is_held(&graph_lock)); + fgd->type = GRAPH_FILTER_NOTRACE; + fgd->seq_ops = &ftrace_graph_seq_ops; + + ret = __ftrace_graph_open(inode, file, fgd); + if (ret < 0) + kfree(fgd); + + mutex_unlock(&graph_lock); return ret; } static int ftrace_graph_release(struct inode *inode, struct file *file) { - if (file->f_mode & FMODE_READ) + struct ftrace_graph_data *fgd; + struct ftrace_hash *old_hash, *new_hash; + struct trace_parser *parser; + int ret = 0; + + if (file->f_mode & FMODE_READ) { + struct seq_file *m = file->private_data; + + fgd = m->private; seq_release(inode, file); - return 0; + } else { + fgd = file->private_data; + } + + + if (file->f_mode & FMODE_WRITE) { + + parser = &fgd->parser; + + if (trace_parser_loaded((parser))) { + ret = ftrace_graph_set_hash(fgd->new_hash, + parser->buffer); + } + + trace_parser_put(parser); + + new_hash = __ftrace_hash_move(fgd->new_hash); + if (!new_hash) { + ret = -ENOMEM; + goto out; + } + + mutex_lock(&graph_lock); + + if (fgd->type == GRAPH_FILTER_FUNCTION) { + old_hash = rcu_dereference_protected(ftrace_graph_hash, + lockdep_is_held(&graph_lock)); + rcu_assign_pointer(ftrace_graph_hash, new_hash); + } else { + old_hash = rcu_dereference_protected(ftrace_graph_notrace_hash, + lockdep_is_held(&graph_lock)); + rcu_assign_pointer(ftrace_graph_notrace_hash, new_hash); + } + + mutex_unlock(&graph_lock); + + /* + * We need to do a hard force of sched synchronization. + * This is because we use preempt_disable() to do RCU, but + * the function tracers can be called where RCU is not watching + * (like before user_exit()). We can not rely on the RCU + * infrastructure to do the synchronization, thus we must do it + * ourselves. + */ + if (old_hash != EMPTY_HASH) + synchronize_rcu_tasks_rude(); + + free_ftrace_hash(old_hash); + } + + out: + free_ftrace_hash(fgd->new_hash); + kfree(fgd); + + return ret; } static int -ftrace_set_func(unsigned long *array, int *idx, char *buffer) +ftrace_graph_set_hash(struct ftrace_hash *hash, char *buffer) { + struct ftrace_glob func_g; struct dyn_ftrace *rec; struct ftrace_page *pg; - int search_len; + struct ftrace_func_entry *entry; int fail = 1; - int type, not; - char *search; - bool exists; - int i; + int not; /* decode regex */ - type = filter_parse_regex(buffer, strlen(buffer), &search, ¬); - if (!not && *idx >= FTRACE_GRAPH_MAX_FUNCS) - return -EBUSY; + func_g.type = filter_parse_regex(buffer, strlen(buffer), + &func_g.search, ¬); - search_len = strlen(search); + func_g.len = strlen(func_g.search); - mutex_lock(&ftrace_lock); + guard(mutex)(&ftrace_lock); - if (unlikely(ftrace_disabled)) { - mutex_unlock(&ftrace_lock); + if (unlikely(ftrace_disabled)) return -ENODEV; - } do_for_each_ftrace_rec(pg, rec) { - if (ftrace_match_record(rec, NULL, search, search_len, type)) { - /* if it is in the array */ - exists = false; - for (i = 0; i < *idx; i++) { - if (array[i] == rec->ip) { - exists = true; - break; - } - } + if (rec->flags & FTRACE_FL_DISABLED) + continue; + + if (ftrace_match_record(rec, &func_g, NULL, 0)) { + entry = ftrace_lookup_ip(hash, rec->ip); if (!not) { fail = 0; - if (!exists) { - array[(*idx)++] = rec->ip; - if (*idx >= FTRACE_GRAPH_MAX_FUNCS) - goto out; - } + + if (entry) + continue; + if (add_hash_entry(hash, rec->ip) == NULL) + return 0; } else { - if (exists) { - array[i] = array[--(*idx)]; - array[*idx] = 0; + if (entry) { + free_hash_entry(hash, entry); fail = 0; } } } + cond_resched(); } while_for_each_ftrace_rec(); -out: - mutex_unlock(&ftrace_lock); - - if (fail) - return -EINVAL; - - ftrace_graph_filter_enabled = !!(*idx); - return 0; + return fail ? -EINVAL : 0; } static ssize_t ftrace_graph_write(struct file *file, const char __user *ubuf, size_t cnt, loff_t *ppos) { - struct trace_parser parser; - ssize_t read, ret; + ssize_t read, ret = 0; + struct ftrace_graph_data *fgd = file->private_data; + struct trace_parser *parser; if (!cnt) return 0; - mutex_lock(&graph_lock); - - if (trace_parser_get_init(&parser, FTRACE_BUFF_MAX)) { - ret = -ENOMEM; - goto out_unlock; + /* Read mode uses seq functions */ + if (file->f_mode & FMODE_READ) { + struct seq_file *m = file->private_data; + fgd = m->private; } - read = trace_get_user(&parser, ubuf, cnt, ppos); + parser = &fgd->parser; - if (read >= 0 && trace_parser_loaded((&parser))) { - parser.buffer[parser.idx] = 0; + read = trace_get_user(parser, ubuf, cnt, ppos); - /* we allow only one expression at a time */ - ret = ftrace_set_func(ftrace_graph_funcs, &ftrace_graph_count, - parser.buffer); - if (ret) - goto out_free; - } + if (read >= 0 && trace_parser_loaded(parser) && + !trace_parser_cont(parser)) { - ret = read; + ret = ftrace_graph_set_hash(fgd->new_hash, + parser->buffer); + trace_parser_clear(parser); + } -out_free: - trace_parser_put(&parser); -out_unlock: - mutex_unlock(&graph_lock); + if (!ret) + ret = read; return ret; } @@ -3891,30 +7062,74 @@ static const struct file_operations ftrace_graph_fops = { .open = ftrace_graph_open, .read = seq_read, .write = ftrace_graph_write, - .llseek = ftrace_filter_lseek, + .llseek = tracing_lseek, + .release = ftrace_graph_release, +}; + +static const struct file_operations ftrace_graph_notrace_fops = { + .open = ftrace_graph_notrace_open, + .read = seq_read, + .write = ftrace_graph_write, + .llseek = tracing_lseek, .release = ftrace_graph_release, }; #endif /* CONFIG_FUNCTION_GRAPH_TRACER */ -static __init int ftrace_init_dyn_debugfs(struct dentry *d_tracer) +void ftrace_create_filter_files(struct ftrace_ops *ops, + struct dentry *parent) +{ + + trace_create_file("set_ftrace_filter", TRACE_MODE_WRITE, parent, + ops, &ftrace_filter_fops); + + trace_create_file("set_ftrace_notrace", TRACE_MODE_WRITE, parent, + ops, &ftrace_notrace_fops); +} + +/* + * The name "destroy_filter_files" is really a misnomer. Although + * in the future, it may actually delete the files, but this is + * really intended to make sure the ops passed in are disabled + * and that when this function returns, the caller is free to + * free the ops. + * + * The "destroy" name is only to match the "create" name that this + * should be paired with. + */ +void ftrace_destroy_filter_files(struct ftrace_ops *ops) +{ + mutex_lock(&ftrace_lock); + if (ops->flags & FTRACE_OPS_FL_ENABLED) + ftrace_shutdown(ops, 0); + ops->flags |= FTRACE_OPS_FL_DELETED; + ftrace_free_filter(ops); + mutex_unlock(&ftrace_lock); +} + +static __init int ftrace_init_dyn_tracefs(struct dentry *d_tracer) { - trace_create_file("available_filter_functions", 0444, + trace_create_file("available_filter_functions", TRACE_MODE_READ, d_tracer, NULL, &ftrace_avail_fops); - trace_create_file("enabled_functions", 0444, + trace_create_file("available_filter_functions_addrs", TRACE_MODE_READ, + d_tracer, NULL, &ftrace_avail_addrs_fops); + + trace_create_file("enabled_functions", TRACE_MODE_READ, d_tracer, NULL, &ftrace_enabled_fops); - trace_create_file("set_ftrace_filter", 0644, d_tracer, - NULL, &ftrace_filter_fops); + trace_create_file("touched_functions", TRACE_MODE_READ, + d_tracer, NULL, &ftrace_touched_fops); - trace_create_file("set_ftrace_notrace", 0644, d_tracer, - NULL, &ftrace_notrace_fops); + ftrace_create_filter_files(&global_ops, d_tracer); #ifdef CONFIG_FUNCTION_GRAPH_TRACER - trace_create_file("set_graph_function", 0444, d_tracer, + trace_create_file("set_graph_function", TRACE_MODE_WRITE, d_tracer, NULL, &ftrace_graph_fops); + trace_create_file("set_graph_notrace", TRACE_MODE_WRITE, d_tracer, + NULL, + &ftrace_graph_notrace_fops); #endif /* CONFIG_FUNCTION_GRAPH_TRACER */ return 0; @@ -3932,28 +7147,41 @@ static int ftrace_cmp_ips(const void *a, const void *b) return 0; } -static void ftrace_swap_ips(void *a, void *b, int size) +#ifdef CONFIG_FTRACE_SORT_STARTUP_TEST +static void test_is_sorted(unsigned long *start, unsigned long count) { - unsigned long *ipa = a; - unsigned long *ipb = b; - unsigned long t; + int i; - t = *ipa; - *ipa = *ipb; - *ipb = t; + for (i = 1; i < count; i++) { + if (WARN(start[i - 1] > start[i], + "[%d] %pS at %lx is not sorted with %pS at %lx\n", i, + (void *)start[i - 1], start[i - 1], + (void *)start[i], start[i])) + break; + } + if (i == count) + pr_info("ftrace section at %px sorted properly\n", start); } +#else +static void test_is_sorted(unsigned long *start, unsigned long count) +{ +} +#endif static int ftrace_process_locs(struct module *mod, unsigned long *start, unsigned long *end) { + struct ftrace_page *pg_unuse = NULL; struct ftrace_page *start_pg; struct ftrace_page *pg; struct dyn_ftrace *rec; + unsigned long skipped = 0; unsigned long count; unsigned long *p; unsigned long addr; unsigned long flags = 0; /* Shut up gcc */ + unsigned long pages; int ret = -ENOMEM; count = end - start; @@ -3961,8 +7189,19 @@ static int ftrace_process_locs(struct module *mod, if (!count) return 0; - sort(start, count, sizeof(*start), - ftrace_cmp_ips, ftrace_swap_ips); + pages = DIV_ROUND_UP(count, ENTRIES_PER_PAGE); + + /* + * Sorting mcount in vmlinux at build time depend on + * CONFIG_BUILDTIME_MCOUNT_SORT, while mcount loc in + * modules can not be sorted at build time. + */ + if (!IS_ENABLED(CONFIG_BUILDTIME_MCOUNT_SORT) || mod) { + sort(start, count, sizeof(*start), + ftrace_cmp_ips, NULL); + } else { + test_is_sorted(start, count); + } start_pg = ftrace_allocate_pages(count); if (!start_pg) @@ -3995,17 +7234,36 @@ static int ftrace_process_locs(struct module *mod, p = start; pg = start_pg; while (p < end) { - addr = ftrace_call_adjust(*p++); + unsigned long end_offset; + + addr = *p++; + /* * Some architecture linkers will pad between * the different mcount_loc sections of different * object files to satisfy alignments. * Skip any NULL pointers. */ - if (!addr) + if (!addr) { + skipped++; + continue; + } + + /* + * If this is core kernel, make sure the address is in core + * or inittext, as weak functions get zeroed and KASLR can + * move them to something other than zero. It just will not + * move it to an area where kernel text is. + */ + if (!mod && !(is_kernel_text(addr) || is_kernel_inittext(addr))) { + skipped++; continue; + } - if (pg->index == pg->size) { + addr = ftrace_call_adjust(addr); + + end_offset = (pg->index+1) * sizeof(pg->records[0]); + if (end_offset > PAGE_SIZE << pg->order) { /* We should have allocated enough */ if (WARN_ON(!pg->next)) break; @@ -4016,15 +7274,14 @@ static int ftrace_process_locs(struct module *mod, rec->ip = addr; } - /* We should have used all pages */ - WARN_ON(pg->next); + if (pg->next) { + pg_unuse = pg->next; + pg->next = NULL; + } /* Assign the last page to ftrace_pages */ ftrace_pages = pg; - /* These new locations need to be initialized */ - ftrace_new_pgs = start_pg; - /* * We only need to disable interrupts on start up * because we are modifying code that an interrupt @@ -4035,29 +7292,232 @@ static int ftrace_process_locs(struct module *mod, */ if (!mod) local_irq_save(flags); - ftrace_update_code(mod); + ftrace_update_code(mod, start_pg); if (!mod) local_irq_restore(flags); ret = 0; out: mutex_unlock(&ftrace_lock); + /* We should have used all pages unless we skipped some */ + if (pg_unuse) { + unsigned long pg_remaining, remaining = 0; + unsigned long skip; + + /* Count the number of entries unused and compare it to skipped. */ + pg_remaining = (ENTRIES_PER_PAGE << pg->order) - pg->index; + + if (!WARN(skipped < pg_remaining, "Extra allocated pages for ftrace")) { + + skip = skipped - pg_remaining; + + for (pg = pg_unuse; pg; pg = pg->next) + remaining += 1 << pg->order; + + pages -= remaining; + + skip = DIV_ROUND_UP(skip, ENTRIES_PER_PAGE); + + /* + * Check to see if the number of pages remaining would + * just fit the number of entries skipped. + */ + WARN(skip != remaining, "Extra allocated pages for ftrace: %lu with %lu skipped", + remaining, skipped); + } + /* Need to synchronize with ftrace_location_range() */ + synchronize_rcu(); + ftrace_free_pages(pg_unuse); + } + + if (!mod) { + count -= skipped; + pr_info("ftrace: allocating %ld entries in %ld pages\n", + count, pages); + } + return ret; } +struct ftrace_mod_func { + struct list_head list; + char *name; + unsigned long ip; + unsigned int size; +}; + +struct ftrace_mod_map { + struct rcu_head rcu; + struct list_head list; + struct module *mod; + unsigned long start_addr; + unsigned long end_addr; + struct list_head funcs; + unsigned int num_funcs; +}; + +static int ftrace_get_trampoline_kallsym(unsigned int symnum, + unsigned long *value, char *type, + char *name, char *module_name, + int *exported) +{ + struct ftrace_ops *op; + + list_for_each_entry_rcu(op, &ftrace_ops_trampoline_list, list) { + if (!op->trampoline || symnum--) + continue; + *value = op->trampoline; + *type = 't'; + strscpy(name, FTRACE_TRAMPOLINE_SYM, KSYM_NAME_LEN); + strscpy(module_name, FTRACE_TRAMPOLINE_MOD, MODULE_NAME_LEN); + *exported = 0; + return 0; + } + + return -ERANGE; +} + +#if defined(CONFIG_DYNAMIC_FTRACE_WITH_DIRECT_CALLS) || defined(CONFIG_MODULES) +/* + * Check if the current ops references the given ip. + * + * If the ops traces all functions, then it was already accounted for. + * If the ops does not trace the current record function, skip it. + * If the ops ignores the function via notrace filter, skip it. + */ +static bool +ops_references_ip(struct ftrace_ops *ops, unsigned long ip) +{ + /* If ops isn't enabled, ignore it */ + if (!(ops->flags & FTRACE_OPS_FL_ENABLED)) + return false; + + /* If ops traces all then it includes this function */ + if (ops_traces_mod(ops)) + return true; + + /* The function must be in the filter */ + if (!ftrace_hash_empty(ops->func_hash->filter_hash) && + !__ftrace_lookup_ip(ops->func_hash->filter_hash, ip)) + return false; + + /* If in notrace hash, we ignore it too */ + if (ftrace_lookup_ip(ops->func_hash->notrace_hash, ip)) + return false; + + return true; +} +#endif + #ifdef CONFIG_MODULES #define next_to_ftrace_page(p) container_of(p, struct ftrace_page, next) +static LIST_HEAD(ftrace_mod_maps); + +static int referenced_filters(struct dyn_ftrace *rec) +{ + struct ftrace_ops *ops; + int cnt = 0; + + for (ops = ftrace_ops_list; ops != &ftrace_list_end; ops = ops->next) { + if (ops_references_ip(ops, rec->ip)) { + if (WARN_ON_ONCE(ops->flags & FTRACE_OPS_FL_DIRECT)) + continue; + if (WARN_ON_ONCE(ops->flags & FTRACE_OPS_FL_IPMODIFY)) + continue; + cnt++; + if (ops->flags & FTRACE_OPS_FL_SAVE_REGS) + rec->flags |= FTRACE_FL_REGS; + if (cnt == 1 && ops->trampoline) + rec->flags |= FTRACE_FL_TRAMP; + else + rec->flags &= ~FTRACE_FL_TRAMP; + } + } + + return cnt; +} + +static void +clear_mod_from_hash(struct ftrace_page *pg, struct ftrace_hash *hash) +{ + struct ftrace_func_entry *entry; + struct dyn_ftrace *rec; + int i; + + if (ftrace_hash_empty(hash)) + return; + + for (i = 0; i < pg->index; i++) { + rec = &pg->records[i]; + entry = __ftrace_lookup_ip(hash, rec->ip); + /* + * Do not allow this rec to match again. + * Yeah, it may waste some memory, but will be removed + * if/when the hash is modified again. + */ + if (entry) + entry->ip = 0; + } +} + +/* Clear any records from hashes */ +static void clear_mod_from_hashes(struct ftrace_page *pg) +{ + struct trace_array *tr; + + mutex_lock(&trace_types_lock); + list_for_each_entry(tr, &ftrace_trace_arrays, list) { + if (!tr->ops || !tr->ops->func_hash) + continue; + mutex_lock(&tr->ops->func_hash->regex_lock); + clear_mod_from_hash(pg, tr->ops->func_hash->filter_hash); + clear_mod_from_hash(pg, tr->ops->func_hash->notrace_hash); + mutex_unlock(&tr->ops->func_hash->regex_lock); + } + mutex_unlock(&trace_types_lock); +} + +static void ftrace_free_mod_map(struct rcu_head *rcu) +{ + struct ftrace_mod_map *mod_map = container_of(rcu, struct ftrace_mod_map, rcu); + struct ftrace_mod_func *mod_func; + struct ftrace_mod_func *n; + + /* All the contents of mod_map are now not visible to readers */ + list_for_each_entry_safe(mod_func, n, &mod_map->funcs, list) { + kfree(mod_func->name); + list_del(&mod_func->list); + kfree(mod_func); + } + + kfree(mod_map); +} + void ftrace_release_mod(struct module *mod) { + struct ftrace_mod_map *mod_map; + struct ftrace_mod_map *n; struct dyn_ftrace *rec; struct ftrace_page **last_pg; + struct ftrace_page *tmp_page = NULL; struct ftrace_page *pg; - int order; mutex_lock(&ftrace_lock); + /* + * To avoid the UAF problem after the module is unloaded, the + * 'mod_map' resource needs to be released unconditionally. + */ + list_for_each_entry_safe(mod_map, n, &ftrace_mod_maps, list) { + if (mod_map->mod == mod) { + list_del_rcu(&mod_map->list); + call_rcu(&mod_map->rcu, ftrace_free_mod_map); + break; + } + } + if (ftrace_disabled) goto out_unlock; @@ -4068,7 +7528,7 @@ void ftrace_release_mod(struct module *mod) last_pg = &ftrace_pages_start; for (pg = ftrace_pages_start; pg; pg = *last_pg) { rec = &pg->records[0]; - if (within_module_core(rec->ip, mod)) { + if (within_module(rec->ip, mod)) { /* * As core pages are first, the first * page should never be a module page. @@ -4080,108 +7540,468 @@ void ftrace_release_mod(struct module *mod) if (pg == ftrace_pages) ftrace_pages = next_to_ftrace_page(last_pg); + ftrace_update_tot_cnt -= pg->index; *last_pg = pg->next; - order = get_count_order(pg->size / ENTRIES_PER_PAGE); - free_pages((unsigned long)pg->records, order); - kfree(pg); + + pg->next = tmp_page; + tmp_page = pg; } else last_pg = &pg->next; } out_unlock: mutex_unlock(&ftrace_lock); + + /* Need to synchronize with ftrace_location_range() */ + if (tmp_page) + synchronize_rcu(); + for (pg = tmp_page; pg; pg = tmp_page) { + + /* Needs to be called outside of ftrace_lock */ + clear_mod_from_hashes(pg); + + if (pg->records) { + free_pages((unsigned long)pg->records, pg->order); + ftrace_number_of_pages -= 1 << pg->order; + } + tmp_page = pg->next; + kfree(pg); + ftrace_number_of_groups--; + } +} + +void ftrace_module_enable(struct module *mod) +{ + struct dyn_ftrace *rec; + struct ftrace_page *pg; + + mutex_lock(&ftrace_lock); + + if (ftrace_disabled) + goto out_unlock; + + /* + * If the tracing is enabled, go ahead and enable the record. + * + * The reason not to enable the record immediately is the + * inherent check of ftrace_make_nop/ftrace_make_call for + * correct previous instructions. Making first the NOP + * conversion puts the module to the correct state, thus + * passing the ftrace_make_call check. + * + * We also delay this to after the module code already set the + * text to read-only, as we now need to set it back to read-write + * so that we can modify the text. + */ + if (ftrace_start_up) + ftrace_arch_code_modify_prepare(); + + do_for_each_ftrace_rec(pg, rec) { + int cnt; + /* + * do_for_each_ftrace_rec() is a double loop. + * module text shares the pg. If a record is + * not part of this module, then skip this pg, + * which the "break" will do. + */ + if (!within_module(rec->ip, mod)) + break; + + cond_resched(); + + /* Weak functions should still be ignored */ + if (!test_for_valid_rec(rec)) { + /* Clear all other flags. Should not be enabled anyway */ + rec->flags = FTRACE_FL_DISABLED; + continue; + } + + cnt = 0; + + /* + * When adding a module, we need to check if tracers are + * currently enabled and if they are, and can trace this record, + * we need to enable the module functions as well as update the + * reference counts for those function records. + */ + if (ftrace_start_up) + cnt += referenced_filters(rec); + + rec->flags &= ~FTRACE_FL_DISABLED; + rec->flags += cnt; + + if (ftrace_start_up && cnt) { + int failed = __ftrace_replace_code(rec, 1); + if (failed) { + ftrace_bug(failed, rec); + goto out_loop; + } + } + + } while_for_each_ftrace_rec(); + + out_loop: + if (ftrace_start_up) + ftrace_arch_code_modify_post_process(); + + out_unlock: + mutex_unlock(&ftrace_lock); + + process_cached_mods(mod->name); } -static void ftrace_init_module(struct module *mod, - unsigned long *start, unsigned long *end) +void ftrace_module_init(struct module *mod) { - if (ftrace_disabled || start == end) + int ret; + + if (ftrace_disabled || !mod->num_ftrace_callsites) return; - ftrace_process_locs(mod, start, end); + + ret = ftrace_process_locs(mod, mod->ftrace_callsites, + mod->ftrace_callsites + mod->num_ftrace_callsites); + if (ret) + pr_warn("ftrace: failed to allocate entries for module '%s' functions\n", + mod->name); } -static int ftrace_module_notify_enter(struct notifier_block *self, - unsigned long val, void *data) +static void save_ftrace_mod_rec(struct ftrace_mod_map *mod_map, + struct dyn_ftrace *rec) { - struct module *mod = data; + struct ftrace_mod_func *mod_func; + unsigned long symsize; + unsigned long offset; + char str[KSYM_SYMBOL_LEN]; + char *modname; + const char *ret; - if (val == MODULE_STATE_COMING) - ftrace_init_module(mod, mod->ftrace_callsites, - mod->ftrace_callsites + - mod->num_ftrace_callsites); - return 0; + ret = kallsyms_lookup(rec->ip, &symsize, &offset, &modname, str); + if (!ret) + return; + + mod_func = kmalloc(sizeof(*mod_func), GFP_KERNEL); + if (!mod_func) + return; + + mod_func->name = kstrdup(str, GFP_KERNEL); + if (!mod_func->name) { + kfree(mod_func); + return; + } + + mod_func->ip = rec->ip - offset; + mod_func->size = symsize; + + mod_map->num_funcs++; + + list_add_rcu(&mod_func->list, &mod_map->funcs); +} + +static struct ftrace_mod_map * +allocate_ftrace_mod_map(struct module *mod, + unsigned long start, unsigned long end) +{ + struct ftrace_mod_map *mod_map; + + if (ftrace_disabled) + return NULL; + + mod_map = kmalloc(sizeof(*mod_map), GFP_KERNEL); + if (!mod_map) + return NULL; + + mod_map->mod = mod; + mod_map->start_addr = start; + mod_map->end_addr = end; + mod_map->num_funcs = 0; + + INIT_LIST_HEAD_RCU(&mod_map->funcs); + + list_add_rcu(&mod_map->list, &ftrace_mod_maps); + + return mod_map; } -static int ftrace_module_notify_exit(struct notifier_block *self, - unsigned long val, void *data) +static int +ftrace_func_address_lookup(struct ftrace_mod_map *mod_map, + unsigned long addr, unsigned long *size, + unsigned long *off, char *sym) { - struct module *mod = data; + struct ftrace_mod_func *found_func = NULL; + struct ftrace_mod_func *mod_func; + + list_for_each_entry_rcu(mod_func, &mod_map->funcs, list) { + if (addr >= mod_func->ip && + addr < mod_func->ip + mod_func->size) { + found_func = mod_func; + break; + } + } - if (val == MODULE_STATE_GOING) - ftrace_release_mod(mod); + if (found_func) { + if (size) + *size = found_func->size; + if (off) + *off = addr - found_func->ip; + return strscpy(sym, found_func->name, KSYM_NAME_LEN); + } return 0; } + +int +ftrace_mod_address_lookup(unsigned long addr, unsigned long *size, + unsigned long *off, char **modname, char *sym) +{ + struct ftrace_mod_map *mod_map; + int ret = 0; + + /* mod_map is freed via call_rcu() */ + preempt_disable(); + list_for_each_entry_rcu(mod_map, &ftrace_mod_maps, list) { + ret = ftrace_func_address_lookup(mod_map, addr, size, off, sym); + if (ret) { + if (modname) + *modname = mod_map->mod->name; + break; + } + } + preempt_enable(); + + return ret; +} + +int ftrace_mod_get_kallsym(unsigned int symnum, unsigned long *value, + char *type, char *name, + char *module_name, int *exported) +{ + struct ftrace_mod_map *mod_map; + struct ftrace_mod_func *mod_func; + int ret; + + preempt_disable(); + list_for_each_entry_rcu(mod_map, &ftrace_mod_maps, list) { + + if (symnum >= mod_map->num_funcs) { + symnum -= mod_map->num_funcs; + continue; + } + + list_for_each_entry_rcu(mod_func, &mod_map->funcs, list) { + if (symnum > 1) { + symnum--; + continue; + } + + *value = mod_func->ip; + *type = 'T'; + strscpy(name, mod_func->name, KSYM_NAME_LEN); + strscpy(module_name, mod_map->mod->name, MODULE_NAME_LEN); + *exported = 1; + preempt_enable(); + return 0; + } + WARN_ON(1); + break; + } + ret = ftrace_get_trampoline_kallsym(symnum, value, type, name, + module_name, exported); + preempt_enable(); + return ret; +} + #else -static int ftrace_module_notify_enter(struct notifier_block *self, - unsigned long val, void *data) +static void save_ftrace_mod_rec(struct ftrace_mod_map *mod_map, + struct dyn_ftrace *rec) { } +static inline struct ftrace_mod_map * +allocate_ftrace_mod_map(struct module *mod, + unsigned long start, unsigned long end) { - return 0; + return NULL; } -static int ftrace_module_notify_exit(struct notifier_block *self, - unsigned long val, void *data) +int ftrace_mod_get_kallsym(unsigned int symnum, unsigned long *value, + char *type, char *name, char *module_name, + int *exported) { - return 0; + int ret; + + preempt_disable(); + ret = ftrace_get_trampoline_kallsym(symnum, value, type, name, + module_name, exported); + preempt_enable(); + return ret; } #endif /* CONFIG_MODULES */ -struct notifier_block ftrace_module_enter_nb = { - .notifier_call = ftrace_module_notify_enter, - .priority = INT_MAX, /* Run before anything that can use kprobes */ +struct ftrace_init_func { + struct list_head list; + unsigned long ip; }; -struct notifier_block ftrace_module_exit_nb = { - .notifier_call = ftrace_module_notify_exit, - .priority = INT_MIN, /* Run after anything that can remove kprobes */ -}; +/* Clear any init ips from hashes */ +static void +clear_func_from_hash(struct ftrace_init_func *func, struct ftrace_hash *hash) +{ + struct ftrace_func_entry *entry; + + entry = ftrace_lookup_ip(hash, func->ip); + /* + * Do not allow this rec to match again. + * Yeah, it may waste some memory, but will be removed + * if/when the hash is modified again. + */ + if (entry) + entry->ip = 0; +} + +static void +clear_func_from_hashes(struct ftrace_init_func *func) +{ + struct trace_array *tr; + + mutex_lock(&trace_types_lock); + list_for_each_entry(tr, &ftrace_trace_arrays, list) { + if (!tr->ops || !tr->ops->func_hash) + continue; + mutex_lock(&tr->ops->func_hash->regex_lock); + clear_func_from_hash(func, tr->ops->func_hash->filter_hash); + clear_func_from_hash(func, tr->ops->func_hash->notrace_hash); + mutex_unlock(&tr->ops->func_hash->regex_lock); + } + mutex_unlock(&trace_types_lock); +} + +static void add_to_clear_hash_list(struct list_head *clear_list, + struct dyn_ftrace *rec) +{ + struct ftrace_init_func *func; + + func = kmalloc(sizeof(*func), GFP_KERNEL); + if (!func) { + MEM_FAIL(1, "alloc failure, ftrace filter could be stale\n"); + return; + } + + func->ip = rec->ip; + list_add(&func->list, clear_list); +} + +void ftrace_free_mem(struct module *mod, void *start_ptr, void *end_ptr) +{ + unsigned long start = (unsigned long)(start_ptr); + unsigned long end = (unsigned long)(end_ptr); + struct ftrace_page **last_pg = &ftrace_pages_start; + struct ftrace_page *tmp_page = NULL; + struct ftrace_page *pg; + struct dyn_ftrace *rec; + struct dyn_ftrace key; + struct ftrace_mod_map *mod_map = NULL; + struct ftrace_init_func *func, *func_next; + LIST_HEAD(clear_hash); + + key.ip = start; + key.flags = end; /* overload flags, as it is unsigned long */ + + mutex_lock(&ftrace_lock); + + /* + * If we are freeing module init memory, then check if + * any tracer is active. If so, we need to save a mapping of + * the module functions being freed with the address. + */ + if (mod && ftrace_ops_list != &ftrace_list_end) + mod_map = allocate_ftrace_mod_map(mod, start, end); + + for (pg = ftrace_pages_start; pg; last_pg = &pg->next, pg = *last_pg) { + if (end < pg->records[0].ip || + start >= (pg->records[pg->index - 1].ip + MCOUNT_INSN_SIZE)) + continue; + again: + rec = bsearch(&key, pg->records, pg->index, + sizeof(struct dyn_ftrace), + ftrace_cmp_recs); + if (!rec) + continue; + + /* rec will be cleared from hashes after ftrace_lock unlock */ + add_to_clear_hash_list(&clear_hash, rec); + + if (mod_map) + save_ftrace_mod_rec(mod_map, rec); + + pg->index--; + ftrace_update_tot_cnt--; + if (!pg->index) { + *last_pg = pg->next; + pg->next = tmp_page; + tmp_page = pg; + pg = container_of(last_pg, struct ftrace_page, next); + if (!(*last_pg)) + ftrace_pages = pg; + continue; + } + memmove(rec, rec + 1, + (pg->index - (rec - pg->records)) * sizeof(*rec)); + /* More than one function may be in this block */ + goto again; + } + mutex_unlock(&ftrace_lock); + + list_for_each_entry_safe(func, func_next, &clear_hash, list) { + clear_func_from_hashes(func); + kfree(func); + } + /* Need to synchronize with ftrace_location_range() */ + if (tmp_page) { + synchronize_rcu(); + ftrace_free_pages(tmp_page); + } +} -extern unsigned long __start_mcount_loc[]; -extern unsigned long __stop_mcount_loc[]; +void __init ftrace_free_init_mem(void) +{ + void *start = (void *)(&__init_begin); + void *end = (void *)(&__init_end); + + ftrace_boot_snapshot(); + + ftrace_free_mem(NULL, start, end); +} + +int __init __weak ftrace_dyn_arch_init(void) +{ + return 0; +} void __init ftrace_init(void) { - unsigned long count, addr, flags; + extern unsigned long __start_mcount_loc[]; + extern unsigned long __stop_mcount_loc[]; + unsigned long count, flags; int ret; - /* Keep the ftrace pointer to the stub */ - addr = (unsigned long)ftrace_stub; - local_irq_save(flags); - ftrace_dyn_arch_init(&addr); + ret = ftrace_dyn_arch_init(); local_irq_restore(flags); - - /* ftrace_dyn_arch_init places the return code in addr */ - if (addr) + if (ret) goto failed; count = __stop_mcount_loc - __start_mcount_loc; - - ret = ftrace_dyn_table_alloc(count); - if (ret) + if (!count) { + pr_info("ftrace: No functions to be traced?\n"); goto failed; - - last_ftrace_enabled = ftrace_enabled = 1; + } ret = ftrace_process_locs(NULL, __start_mcount_loc, __stop_mcount_loc); + if (ret) { + pr_warn("ftrace: failed to allocate entries for functions\n"); + goto failed; + } - ret = register_module_notifier(&ftrace_module_enter_nb); - if (ret) - pr_warning("Failed to register trace ftrace module enter notifier\n"); + pr_info("ftrace: allocated %ld pages with %ld groups\n", + ftrace_number_of_pages, ftrace_number_of_groups); - ret = register_module_notifier(&ftrace_module_exit_nb); - if (ret) - pr_warning("Failed to register trace ftrace module exit notifier\n"); + last_ftrace_enabled = ftrace_enabled = 1; set_ftrace_early_filters(); @@ -4190,12 +8010,50 @@ void __init ftrace_init(void) ftrace_disabled = 1; } +/* Do nothing if arch does not support this */ +void __weak arch_ftrace_update_trampoline(struct ftrace_ops *ops) +{ +} + +static void ftrace_update_trampoline(struct ftrace_ops *ops) +{ + unsigned long trampoline = ops->trampoline; + + arch_ftrace_update_trampoline(ops); + if (ops->trampoline && ops->trampoline != trampoline && + (ops->flags & FTRACE_OPS_FL_ALLOC_TRAMP)) { + /* Add to kallsyms before the perf events */ + ftrace_add_trampoline_to_kallsyms(ops); + perf_event_ksymbol(PERF_RECORD_KSYMBOL_TYPE_OOL, + ops->trampoline, ops->trampoline_size, false, + FTRACE_TRAMPOLINE_SYM); + /* + * Record the perf text poke event after the ksymbol register + * event. + */ + perf_event_text_poke((void *)ops->trampoline, NULL, 0, + (void *)ops->trampoline, + ops->trampoline_size); + } +} + +void ftrace_init_trace_array(struct trace_array *tr) +{ + if (tr->flags & TRACE_ARRAY_FL_MOD_INIT) + return; + + INIT_LIST_HEAD(&tr->func_probes); + INIT_LIST_HEAD(&tr->mod_trace); + INIT_LIST_HEAD(&tr->mod_notrace); + + tr->flags |= TRACE_ARRAY_FL_MOD_INIT; +} #else -static struct ftrace_ops global_ops = { +struct ftrace_ops global_ops = { .func = ftrace_stub, - .flags = FTRACE_OPS_FL_RECURSION_SAFE | FTRACE_OPS_FL_INITIALIZED, - INIT_REGEX_LOCK(global_ops) + .flags = FTRACE_OPS_FL_INITIALIZED | + FTRACE_OPS_FL_PID, }; static int __init ftrace_nodyn_init(void) @@ -4205,79 +8063,79 @@ static int __init ftrace_nodyn_init(void) } core_initcall(ftrace_nodyn_init); -static inline int ftrace_init_dyn_debugfs(struct dentry *d_tracer) { return 0; } -static inline void ftrace_startup_enable(int command) { } -/* Keep as macros so we do not need to define the commands */ -# define ftrace_startup(ops, command) \ - ({ \ - (ops)->flags |= FTRACE_OPS_FL_ENABLED; \ - 0; \ - }) -# define ftrace_shutdown(ops, command) do { } while (0) -# define ftrace_startup_sysctl() do { } while (0) -# define ftrace_shutdown_sysctl() do { } while (0) +static inline int ftrace_init_dyn_tracefs(struct dentry *d_tracer) { return 0; } +static inline void ftrace_startup_all(int command) { } -static inline int -ftrace_ops_test(struct ftrace_ops *ops, unsigned long ip) +static void ftrace_update_trampoline(struct ftrace_ops *ops) { - return 1; } #endif /* CONFIG_DYNAMIC_FTRACE */ -static void -ftrace_ops_control_func(unsigned long ip, unsigned long parent_ip, - struct ftrace_ops *op, struct pt_regs *regs) +__init void ftrace_init_global_array_ops(struct trace_array *tr) { - if (unlikely(trace_recursion_test(TRACE_CONTROL_BIT))) - return; + tr->ops = &global_ops; + if (!global_ops.private) + global_ops.private = tr; + ftrace_init_trace_array(tr); + init_array_fgraph_ops(tr, tr->ops); +} - /* - * Some of the ops may be dynamically allocated, - * they must be freed after a synchronize_sched(). - */ - preempt_disable_notrace(); - trace_recursion_set(TRACE_CONTROL_BIT); - do_for_each_ftrace_op(op, ftrace_control_list) { - if (!(op->flags & FTRACE_OPS_FL_STUB) && - !ftrace_function_local_disabled(op) && - ftrace_ops_test(op, ip)) - op->func(ip, parent_ip, op, regs); - } while_for_each_ftrace_op(op); - trace_recursion_clear(TRACE_CONTROL_BIT); - preempt_enable_notrace(); +void ftrace_init_array_ops(struct trace_array *tr, ftrace_func_t func) +{ + /* If we filter on pids, update to use the pid function */ + if (tr->flags & TRACE_ARRAY_FL_GLOBAL) { + if (WARN_ON(tr->ops->func != ftrace_stub)) + printk("ftrace ops had %pS for function\n", + tr->ops->func); + } + tr->ops->func = func; + tr->ops->private = tr; } -static struct ftrace_ops control_ops = { - .func = ftrace_ops_control_func, - .flags = FTRACE_OPS_FL_RECURSION_SAFE | FTRACE_OPS_FL_INITIALIZED, - INIT_REGEX_LOCK(control_ops) -}; +void ftrace_reset_array_ops(struct trace_array *tr) +{ + tr->ops->func = ftrace_stub; +} -static inline void +static nokprobe_inline void __ftrace_ops_list_func(unsigned long ip, unsigned long parent_ip, - struct ftrace_ops *ignored, struct pt_regs *regs) + struct ftrace_ops *ignored, struct ftrace_regs *fregs) { + struct pt_regs *regs = ftrace_get_regs(fregs); struct ftrace_ops *op; int bit; - if (function_trace_stop) - return; - - bit = trace_test_and_set_recursion(TRACE_LIST_START, TRACE_LIST_MAX); + /* + * The ftrace_test_and_set_recursion() will disable preemption, + * which is required since some of the ops may be dynamically + * allocated, they must be freed after a synchronize_rcu(). + */ + bit = trace_test_and_set_recursion(ip, parent_ip, TRACE_LIST_START); if (bit < 0) return; - /* - * Some of the ops may be dynamically allocated, - * they must be freed after a synchronize_sched(). - */ - preempt_disable_notrace(); do_for_each_ftrace_op(op, ftrace_ops_list) { - if (ftrace_ops_test(op, ip)) - op->func(ip, parent_ip, op, regs); + /* Stub functions don't need to be called nor tested */ + if (op->flags & FTRACE_OPS_FL_STUB) + continue; + /* + * Check the following for each ops before calling their func: + * if RCU flag is set, then rcu_is_watching() must be true + * Otherwise test if the ip matches the ops filter + * + * If any of the above fails then the op->func() is not executed. + */ + if ((!(op->flags & FTRACE_OPS_FL_RCU) || rcu_is_watching()) && + ftrace_ops_test(op, ip, regs)) { + if (FTRACE_WARN_ON(!op->func)) { + pr_warn("op=%p %pS\n", op, op); + goto out; + } + op->func(ip, parent_ip, op, fregs); + } } while_for_each_ftrace_op(op); - preempt_enable_notrace(); +out: trace_clear_recursion(bit); } @@ -4292,193 +8150,240 @@ __ftrace_ops_list_func(unsigned long ip, unsigned long parent_ip, * being NULL, or CONFIG_DYNAMIC_FTRACE_WITH_REGS. * Note, CONFIG_DYNAMIC_FTRACE_WITH_REGS expects a full regs to be saved. * An architecture can pass partial regs with ftrace_ops and still - * set the ARCH_SUPPORT_FTARCE_OPS. + * set the ARCH_SUPPORTS_FTRACE_OPS. + * + * In vmlinux.lds.h, ftrace_ops_list_func() is defined to be + * arch_ftrace_ops_list_func. */ #if ARCH_SUPPORTS_FTRACE_OPS -static void ftrace_ops_list_func(unsigned long ip, unsigned long parent_ip, - struct ftrace_ops *op, struct pt_regs *regs) +void arch_ftrace_ops_list_func(unsigned long ip, unsigned long parent_ip, + struct ftrace_ops *op, struct ftrace_regs *fregs) { - __ftrace_ops_list_func(ip, parent_ip, NULL, regs); + kmsan_unpoison_memory(fregs, ftrace_regs_size()); + __ftrace_ops_list_func(ip, parent_ip, NULL, fregs); } #else -static void ftrace_ops_no_ops(unsigned long ip, unsigned long parent_ip) +void arch_ftrace_ops_list_func(unsigned long ip, unsigned long parent_ip) { __ftrace_ops_list_func(ip, parent_ip, NULL, NULL); } #endif +NOKPROBE_SYMBOL(arch_ftrace_ops_list_func); -static void clear_ftrace_swapper(void) +/* + * If there's only one function registered but it does not support + * recursion, needs RCU protection, then this function will be called + * by the mcount trampoline. + */ +static void ftrace_ops_assist_func(unsigned long ip, unsigned long parent_ip, + struct ftrace_ops *op, struct ftrace_regs *fregs) { - struct task_struct *p; - int cpu; + int bit; - get_online_cpus(); - for_each_online_cpu(cpu) { - p = idle_task(cpu); - clear_tsk_trace_trace(p); - } - put_online_cpus(); + bit = trace_test_and_set_recursion(ip, parent_ip, TRACE_LIST_START); + if (bit < 0) + return; + + if (!(op->flags & FTRACE_OPS_FL_RCU) || rcu_is_watching()) + op->func(ip, parent_ip, op, fregs); + + trace_clear_recursion(bit); } +NOKPROBE_SYMBOL(ftrace_ops_assist_func); -static void set_ftrace_swapper(void) +/** + * ftrace_ops_get_func - get the function a trampoline should call + * @ops: the ops to get the function for + * + * Normally the mcount trampoline will call the ops->func, but there + * are times that it should not. For example, if the ops does not + * have its own recursion protection, then it should call the + * ftrace_ops_assist_func() instead. + * + * Returns: the function that the trampoline should call for @ops. + */ +ftrace_func_t ftrace_ops_get_func(struct ftrace_ops *ops) { - struct task_struct *p; - int cpu; + /* + * If the function does not handle recursion or needs to be RCU safe, + * then we need to call the assist handler. + */ + if (ops->flags & (FTRACE_OPS_FL_RECURSION | + FTRACE_OPS_FL_RCU)) + return ftrace_ops_assist_func; - get_online_cpus(); - for_each_online_cpu(cpu) { - p = idle_task(cpu); - set_tsk_trace_trace(p); - } - put_online_cpus(); + return ops->func; } -static void clear_ftrace_pid(struct pid *pid) +static void +ftrace_filter_pid_sched_switch_probe(void *data, bool preempt, + struct task_struct *prev, + struct task_struct *next, + unsigned int prev_state) { - struct task_struct *p; + struct trace_array *tr = data; + struct trace_pid_list *pid_list; + struct trace_pid_list *no_pid_list; - rcu_read_lock(); - do_each_pid_task(pid, PIDTYPE_PID, p) { - clear_tsk_trace_trace(p); - } while_each_pid_task(pid, PIDTYPE_PID, p); - rcu_read_unlock(); + pid_list = rcu_dereference_sched(tr->function_pids); + no_pid_list = rcu_dereference_sched(tr->function_no_pids); - put_pid(pid); + if (trace_ignore_this_task(pid_list, no_pid_list, next)) + this_cpu_write(tr->array_buffer.data->ftrace_ignore_pid, + FTRACE_PID_IGNORE); + else + this_cpu_write(tr->array_buffer.data->ftrace_ignore_pid, + next->pid); } -static void set_ftrace_pid(struct pid *pid) +static void +ftrace_pid_follow_sched_process_fork(void *data, + struct task_struct *self, + struct task_struct *task) { - struct task_struct *p; + struct trace_pid_list *pid_list; + struct trace_array *tr = data; - rcu_read_lock(); - do_each_pid_task(pid, PIDTYPE_PID, p) { - set_tsk_trace_trace(p); - } while_each_pid_task(pid, PIDTYPE_PID, p); - rcu_read_unlock(); + pid_list = rcu_dereference_sched(tr->function_pids); + trace_filter_add_remove_task(pid_list, self, task); + + pid_list = rcu_dereference_sched(tr->function_no_pids); + trace_filter_add_remove_task(pid_list, self, task); } -static void clear_ftrace_pid_task(struct pid *pid) +static void +ftrace_pid_follow_sched_process_exit(void *data, struct task_struct *task) { - if (pid == ftrace_swapper_pid) - clear_ftrace_swapper(); - else - clear_ftrace_pid(pid); + struct trace_pid_list *pid_list; + struct trace_array *tr = data; + + pid_list = rcu_dereference_sched(tr->function_pids); + trace_filter_add_remove_task(pid_list, NULL, task); + + pid_list = rcu_dereference_sched(tr->function_no_pids); + trace_filter_add_remove_task(pid_list, NULL, task); } -static void set_ftrace_pid_task(struct pid *pid) +void ftrace_pid_follow_fork(struct trace_array *tr, bool enable) { - if (pid == ftrace_swapper_pid) - set_ftrace_swapper(); - else - set_ftrace_pid(pid); + if (enable) { + register_trace_sched_process_fork(ftrace_pid_follow_sched_process_fork, + tr); + register_trace_sched_process_free(ftrace_pid_follow_sched_process_exit, + tr); + } else { + unregister_trace_sched_process_fork(ftrace_pid_follow_sched_process_fork, + tr); + unregister_trace_sched_process_free(ftrace_pid_follow_sched_process_exit, + tr); + } } -static int ftrace_pid_add(int p) +static void clear_ftrace_pids(struct trace_array *tr, int type) { - struct pid *pid; - struct ftrace_pid *fpid; - int ret = -EINVAL; - - mutex_lock(&ftrace_lock); - - if (!p) - pid = ftrace_swapper_pid; - else - pid = find_get_pid(p); + struct trace_pid_list *pid_list; + struct trace_pid_list *no_pid_list; + int cpu; - if (!pid) - goto out; + pid_list = rcu_dereference_protected(tr->function_pids, + lockdep_is_held(&ftrace_lock)); + no_pid_list = rcu_dereference_protected(tr->function_no_pids, + lockdep_is_held(&ftrace_lock)); - ret = 0; + /* Make sure there's something to do */ + if (!pid_type_enabled(type, pid_list, no_pid_list)) + return; - list_for_each_entry(fpid, &ftrace_pids, list) - if (fpid->pid == pid) - goto out_put; + /* See if the pids still need to be checked after this */ + if (!still_need_pid_events(type, pid_list, no_pid_list)) { + unregister_trace_sched_switch(ftrace_filter_pid_sched_switch_probe, tr); + for_each_possible_cpu(cpu) + per_cpu_ptr(tr->array_buffer.data, cpu)->ftrace_ignore_pid = FTRACE_PID_TRACE; + } - ret = -ENOMEM; + if (type & TRACE_PIDS) + rcu_assign_pointer(tr->function_pids, NULL); - fpid = kmalloc(sizeof(*fpid), GFP_KERNEL); - if (!fpid) - goto out_put; + if (type & TRACE_NO_PIDS) + rcu_assign_pointer(tr->function_no_pids, NULL); - list_add(&fpid->list, &ftrace_pids); - fpid->pid = pid; + /* Wait till all users are no longer using pid filtering */ + synchronize_rcu(); - set_ftrace_pid_task(pid); + if ((type & TRACE_PIDS) && pid_list) + trace_pid_list_free(pid_list); - ftrace_update_pid_func(); - ftrace_startup_enable(0); + if ((type & TRACE_NO_PIDS) && no_pid_list) + trace_pid_list_free(no_pid_list); +} - mutex_unlock(&ftrace_lock); - return 0; +void ftrace_clear_pids(struct trace_array *tr) +{ + mutex_lock(&ftrace_lock); -out_put: - if (pid != ftrace_swapper_pid) - put_pid(pid); + clear_ftrace_pids(tr, TRACE_PIDS | TRACE_NO_PIDS); -out: mutex_unlock(&ftrace_lock); - return ret; } -static void ftrace_pid_reset(void) +static void ftrace_pid_reset(struct trace_array *tr, int type) { - struct ftrace_pid *fpid, *safe; - mutex_lock(&ftrace_lock); - list_for_each_entry_safe(fpid, safe, &ftrace_pids, list) { - struct pid *pid = fpid->pid; - - clear_ftrace_pid_task(pid); - - list_del(&fpid->list); - kfree(fpid); - } + clear_ftrace_pids(tr, type); ftrace_update_pid_func(); - ftrace_startup_enable(0); + ftrace_startup_all(0); mutex_unlock(&ftrace_lock); } +/* Greater than any max PID */ +#define FTRACE_NO_PIDS (void *)(PID_MAX_LIMIT + 1) + static void *fpid_start(struct seq_file *m, loff_t *pos) + __acquires(RCU) { + struct trace_pid_list *pid_list; + struct trace_array *tr = m->private; + mutex_lock(&ftrace_lock); + rcu_read_lock_sched(); + + pid_list = rcu_dereference_sched(tr->function_pids); - if (list_empty(&ftrace_pids) && (!*pos)) - return (void *) 1; + if (!pid_list) + return !(*pos) ? FTRACE_NO_PIDS : NULL; - return seq_list_start(&ftrace_pids, *pos); + return trace_pid_start(pid_list, pos); } static void *fpid_next(struct seq_file *m, void *v, loff_t *pos) { - if (v == (void *)1) - return NULL; + struct trace_array *tr = m->private; + struct trace_pid_list *pid_list = rcu_dereference_sched(tr->function_pids); - return seq_list_next(v, &ftrace_pids, pos); + if (v == FTRACE_NO_PIDS) { + (*pos)++; + return NULL; + } + return trace_pid_next(pid_list, v, pos); } static void fpid_stop(struct seq_file *m, void *p) + __releases(RCU) { + rcu_read_unlock_sched(); mutex_unlock(&ftrace_lock); } static int fpid_show(struct seq_file *m, void *v) { - const struct ftrace_pid *fpid = list_entry(v, struct ftrace_pid, list); - - if (v == (void *)1) { - seq_printf(m, "no pid\n"); + if (v == FTRACE_NO_PIDS) { + seq_puts(m, "no pid\n"); return 0; } - if (fpid->pid == ftrace_swapper_pid) - seq_printf(m, "swapper tasks\n"); - else - seq_printf(m, "%u\n", pid_vnr(fpid->pid)); - - return 0; + return trace_pid_show(m, v); } static const struct seq_operations ftrace_pid_sops = { @@ -4488,89 +8393,245 @@ static const struct seq_operations ftrace_pid_sops = { .show = fpid_show, }; -static int -ftrace_pid_open(struct inode *inode, struct file *file) +static void *fnpid_start(struct seq_file *m, loff_t *pos) + __acquires(RCU) +{ + struct trace_pid_list *pid_list; + struct trace_array *tr = m->private; + + mutex_lock(&ftrace_lock); + rcu_read_lock_sched(); + + pid_list = rcu_dereference_sched(tr->function_no_pids); + + if (!pid_list) + return !(*pos) ? FTRACE_NO_PIDS : NULL; + + return trace_pid_start(pid_list, pos); +} + +static void *fnpid_next(struct seq_file *m, void *v, loff_t *pos) +{ + struct trace_array *tr = m->private; + struct trace_pid_list *pid_list = rcu_dereference_sched(tr->function_no_pids); + + if (v == FTRACE_NO_PIDS) { + (*pos)++; + return NULL; + } + return trace_pid_next(pid_list, v, pos); +} + +static const struct seq_operations ftrace_no_pid_sops = { + .start = fnpid_start, + .next = fnpid_next, + .stop = fpid_stop, + .show = fpid_show, +}; + +static int pid_open(struct inode *inode, struct file *file, int type) { + const struct seq_operations *seq_ops; + struct trace_array *tr = inode->i_private; + struct seq_file *m; int ret = 0; + ret = tracing_check_open_get_tr(tr); + if (ret) + return ret; + if ((file->f_mode & FMODE_WRITE) && (file->f_flags & O_TRUNC)) - ftrace_pid_reset(); + ftrace_pid_reset(tr, type); + + switch (type) { + case TRACE_PIDS: + seq_ops = &ftrace_pid_sops; + break; + case TRACE_NO_PIDS: + seq_ops = &ftrace_no_pid_sops; + break; + default: + trace_array_put(tr); + WARN_ON_ONCE(1); + return -EINVAL; + } - if (file->f_mode & FMODE_READ) - ret = seq_open(file, &ftrace_pid_sops); + ret = seq_open(file, seq_ops); + if (ret < 0) { + trace_array_put(tr); + } else { + m = file->private_data; + /* copy tr over to seq ops */ + m->private = tr; + } return ret; } +static int +ftrace_pid_open(struct inode *inode, struct file *file) +{ + return pid_open(inode, file, TRACE_PIDS); +} + +static int +ftrace_no_pid_open(struct inode *inode, struct file *file) +{ + return pid_open(inode, file, TRACE_NO_PIDS); +} + +static void ignore_task_cpu(void *data) +{ + struct trace_array *tr = data; + struct trace_pid_list *pid_list; + struct trace_pid_list *no_pid_list; + + /* + * This function is called by on_each_cpu() while the + * event_mutex is held. + */ + pid_list = rcu_dereference_protected(tr->function_pids, + mutex_is_locked(&ftrace_lock)); + no_pid_list = rcu_dereference_protected(tr->function_no_pids, + mutex_is_locked(&ftrace_lock)); + + if (trace_ignore_this_task(pid_list, no_pid_list, current)) + this_cpu_write(tr->array_buffer.data->ftrace_ignore_pid, + FTRACE_PID_IGNORE); + else + this_cpu_write(tr->array_buffer.data->ftrace_ignore_pid, + current->pid); +} + static ssize_t -ftrace_pid_write(struct file *filp, const char __user *ubuf, - size_t cnt, loff_t *ppos) +pid_write(struct file *filp, const char __user *ubuf, + size_t cnt, loff_t *ppos, int type) { - char buf[64], *tmp; - long val; - int ret; + struct seq_file *m = filp->private_data; + struct trace_array *tr = m->private; + struct trace_pid_list *filtered_pids; + struct trace_pid_list *other_pids; + struct trace_pid_list *pid_list; + ssize_t ret; + + if (!cnt) + return 0; - if (cnt >= sizeof(buf)) + guard(mutex)(&ftrace_lock); + + switch (type) { + case TRACE_PIDS: + filtered_pids = rcu_dereference_protected(tr->function_pids, + lockdep_is_held(&ftrace_lock)); + other_pids = rcu_dereference_protected(tr->function_no_pids, + lockdep_is_held(&ftrace_lock)); + break; + case TRACE_NO_PIDS: + filtered_pids = rcu_dereference_protected(tr->function_no_pids, + lockdep_is_held(&ftrace_lock)); + other_pids = rcu_dereference_protected(tr->function_pids, + lockdep_is_held(&ftrace_lock)); + break; + default: + WARN_ON_ONCE(1); return -EINVAL; + } + + ret = trace_pid_write(filtered_pids, &pid_list, ubuf, cnt); + if (ret < 0) + return ret; + + switch (type) { + case TRACE_PIDS: + rcu_assign_pointer(tr->function_pids, pid_list); + break; + case TRACE_NO_PIDS: + rcu_assign_pointer(tr->function_no_pids, pid_list); + break; + } - if (copy_from_user(&buf, ubuf, cnt)) - return -EFAULT; - buf[cnt] = 0; + if (filtered_pids) { + synchronize_rcu(); + trace_pid_list_free(filtered_pids); + } else if (pid_list && !other_pids) { + /* Register a probe to set whether to ignore the tracing of a task */ + register_trace_sched_switch(ftrace_filter_pid_sched_switch_probe, tr); + } /* - * Allow "echo > set_ftrace_pid" or "echo -n '' > set_ftrace_pid" - * to clean the filter quietly. + * Ignoring of pids is done at task switch. But we have to + * check for those tasks that are currently running. + * Always do this in case a pid was appended or removed. */ - tmp = strstrip(buf); - if (strlen(tmp) == 0) - return 1; + on_each_cpu(ignore_task_cpu, tr, 1); - ret = kstrtol(tmp, 10, &val); - if (ret < 0) - return ret; + ftrace_update_pid_func(); + ftrace_startup_all(0); + + *ppos += ret; + + return ret; +} - ret = ftrace_pid_add(val); +static ssize_t +ftrace_pid_write(struct file *filp, const char __user *ubuf, + size_t cnt, loff_t *ppos) +{ + return pid_write(filp, ubuf, cnt, ppos, TRACE_PIDS); +} - return ret ? ret : cnt; +static ssize_t +ftrace_no_pid_write(struct file *filp, const char __user *ubuf, + size_t cnt, loff_t *ppos) +{ + return pid_write(filp, ubuf, cnt, ppos, TRACE_NO_PIDS); } static int ftrace_pid_release(struct inode *inode, struct file *file) { - if (file->f_mode & FMODE_READ) - seq_release(inode, file); + struct trace_array *tr = inode->i_private; - return 0; + trace_array_put(tr); + + return seq_release(inode, file); } static const struct file_operations ftrace_pid_fops = { .open = ftrace_pid_open, .write = ftrace_pid_write, .read = seq_read, - .llseek = ftrace_filter_lseek, + .llseek = tracing_lseek, .release = ftrace_pid_release, }; -static __init int ftrace_init_debugfs(void) -{ - struct dentry *d_tracer; - - d_tracer = tracing_init_dentry(); - if (!d_tracer) - return 0; - - ftrace_init_dyn_debugfs(d_tracer); +static const struct file_operations ftrace_no_pid_fops = { + .open = ftrace_no_pid_open, + .write = ftrace_no_pid_write, + .read = seq_read, + .llseek = tracing_lseek, + .release = ftrace_pid_release, +}; - trace_create_file("set_ftrace_pid", 0644, d_tracer, - NULL, &ftrace_pid_fops); +void ftrace_init_tracefs(struct trace_array *tr, struct dentry *d_tracer) +{ + trace_create_file("set_ftrace_pid", TRACE_MODE_WRITE, d_tracer, + tr, &ftrace_pid_fops); + trace_create_file("set_ftrace_notrace_pid", TRACE_MODE_WRITE, + d_tracer, tr, &ftrace_no_pid_fops); +} - ftrace_profile_debugfs(d_tracer); +void __init ftrace_init_tracefs_toplevel(struct trace_array *tr, + struct dentry *d_tracer) +{ + /* Only the top level directory has the dyn_tracefs and profile */ + WARN_ON(!(tr->flags & TRACE_ARRAY_FL_GLOBAL)); - return 0; + ftrace_init_dyn_tracefs(d_tracer); + ftrace_profile_tracefs(d_tracer); } -fs_initcall(ftrace_init_debugfs); /** * ftrace_kill - kill ftrace @@ -4583,379 +8644,386 @@ void ftrace_kill(void) { ftrace_disabled = 1; ftrace_enabled = 0; - clear_ftrace_function(); + ftrace_trace_function = ftrace_stub; + kprobe_ftrace_kill(); } /** - * Test if ftrace is dead or not. + * ftrace_is_dead - Test if ftrace is dead or not. + * + * Returns: 1 if ftrace is "dead", zero otherwise. */ int ftrace_is_dead(void) { return ftrace_disabled; } -/** - * register_ftrace_function - register a function for profiling - * @ops - ops structure that holds the function for profiling. +#ifdef CONFIG_DYNAMIC_FTRACE_WITH_DIRECT_CALLS +/* + * When registering ftrace_ops with IPMODIFY, it is necessary to make sure + * it doesn't conflict with any direct ftrace_ops. If there is existing + * direct ftrace_ops on a kernel function being patched, call + * FTRACE_OPS_CMD_ENABLE_SHARE_IPMODIFY_PEER on it to enable sharing. * - * Register a function to be called by all functions in the - * kernel. + * @ops: ftrace_ops being registered. * - * Note: @ops->func and all the functions it calls must be labeled - * with "notrace", otherwise it will go into a - * recursive loop. + * Returns: + * 0 on success; + * Negative on failure. */ -int register_ftrace_function(struct ftrace_ops *ops) +static int prepare_direct_functions_for_ipmodify(struct ftrace_ops *ops) { - int ret = -1; - - ftrace_ops_init(ops); + struct ftrace_func_entry *entry; + struct ftrace_hash *hash; + struct ftrace_ops *op; + int size, i, ret; - mutex_lock(&ftrace_lock); + lockdep_assert_held_once(&direct_mutex); - ret = __register_ftrace_function(ops); - if (!ret) - ret = ftrace_startup(ops, 0); + if (!(ops->flags & FTRACE_OPS_FL_IPMODIFY)) + return 0; - mutex_unlock(&ftrace_lock); + hash = ops->func_hash->filter_hash; + size = 1 << hash->size_bits; + for (i = 0; i < size; i++) { + hlist_for_each_entry(entry, &hash->buckets[i], hlist) { + unsigned long ip = entry->ip; + bool found_op = false; - return ret; -} -EXPORT_SYMBOL_GPL(register_ftrace_function); + mutex_lock(&ftrace_lock); + do_for_each_ftrace_op(op, ftrace_ops_list) { + if (!(op->flags & FTRACE_OPS_FL_DIRECT)) + continue; + if (ops_references_ip(op, ip)) { + found_op = true; + break; + } + } while_for_each_ftrace_op(op); + mutex_unlock(&ftrace_lock); -/** - * unregister_ftrace_function - unregister a function for profiling. - * @ops - ops structure that holds the function to unregister - * - * Unregister a function that was added to be called by ftrace profiling. - */ -int unregister_ftrace_function(struct ftrace_ops *ops) -{ - int ret; + if (found_op) { + if (!op->ops_func) + return -EBUSY; - mutex_lock(&ftrace_lock); - ret = __unregister_ftrace_function(ops); - if (!ret) - ftrace_shutdown(ops, 0); - mutex_unlock(&ftrace_lock); + ret = op->ops_func(op, FTRACE_OPS_CMD_ENABLE_SHARE_IPMODIFY_PEER); + if (ret) + return ret; + } + } + } - return ret; + return 0; } -EXPORT_SYMBOL_GPL(unregister_ftrace_function); -int -ftrace_enable_sysctl(struct ctl_table *table, int write, - void __user *buffer, size_t *lenp, - loff_t *ppos) +/* + * Similar to prepare_direct_functions_for_ipmodify, clean up after ops + * with IPMODIFY is unregistered. The cleanup is optional for most DIRECT + * ops. + */ +static void cleanup_direct_functions_after_ipmodify(struct ftrace_ops *ops) { - int ret = -ENODEV; - - mutex_lock(&ftrace_lock); - - if (unlikely(ftrace_disabled)) - goto out; - - ret = proc_dointvec(table, write, buffer, lenp, ppos); - - if (ret || !write || (last_ftrace_enabled == !!ftrace_enabled)) - goto out; - - last_ftrace_enabled = !!ftrace_enabled; + struct ftrace_func_entry *entry; + struct ftrace_hash *hash; + struct ftrace_ops *op; + int size, i; - if (ftrace_enabled) { + if (!(ops->flags & FTRACE_OPS_FL_IPMODIFY)) + return; - ftrace_startup_sysctl(); + mutex_lock(&direct_mutex); - /* we are starting ftrace again */ - if (ftrace_ops_list != &ftrace_list_end) - update_ftrace_function(); + hash = ops->func_hash->filter_hash; + size = 1 << hash->size_bits; + for (i = 0; i < size; i++) { + hlist_for_each_entry(entry, &hash->buckets[i], hlist) { + unsigned long ip = entry->ip; + bool found_op = false; - } else { - /* stopping ftrace calls (just send to ftrace_stub) */ - ftrace_trace_function = ftrace_stub; + mutex_lock(&ftrace_lock); + do_for_each_ftrace_op(op, ftrace_ops_list) { + if (!(op->flags & FTRACE_OPS_FL_DIRECT)) + continue; + if (ops_references_ip(op, ip)) { + found_op = true; + break; + } + } while_for_each_ftrace_op(op); + mutex_unlock(&ftrace_lock); - ftrace_shutdown_sysctl(); + /* The cleanup is optional, ignore any errors */ + if (found_op && op->ops_func) + op->ops_func(op, FTRACE_OPS_CMD_DISABLE_SHARE_IPMODIFY_PEER); + } } - - out: - mutex_unlock(&ftrace_lock); - return ret; + mutex_unlock(&direct_mutex); } -#ifdef CONFIG_FUNCTION_GRAPH_TRACER +#define lock_direct_mutex() mutex_lock(&direct_mutex) +#define unlock_direct_mutex() mutex_unlock(&direct_mutex) -static int ftrace_graph_active; -static struct notifier_block ftrace_suspend_notifier; +#else /* CONFIG_DYNAMIC_FTRACE_WITH_DIRECT_CALLS */ -int ftrace_graph_entry_stub(struct ftrace_graph_ent *trace) +static int prepare_direct_functions_for_ipmodify(struct ftrace_ops *ops) { return 0; } -/* The callbacks that hook a function */ -trace_func_graph_ret_t ftrace_graph_return = - (trace_func_graph_ret_t)ftrace_stub; -trace_func_graph_ent_t ftrace_graph_entry = ftrace_graph_entry_stub; - -/* Try to assign a return stack array on FTRACE_RETSTACK_ALLOC_SIZE tasks. */ -static int alloc_retstack_tasklist(struct ftrace_ret_stack **ret_stack_list) +static void cleanup_direct_functions_after_ipmodify(struct ftrace_ops *ops) { - int i; - int ret = 0; - unsigned long flags; - int start = 0, end = FTRACE_RETSTACK_ALLOC_SIZE; - struct task_struct *g, *t; - - for (i = 0; i < FTRACE_RETSTACK_ALLOC_SIZE; i++) { - ret_stack_list[i] = kmalloc(FTRACE_RETFUNC_DEPTH - * sizeof(struct ftrace_ret_stack), - GFP_KERNEL); - if (!ret_stack_list[i]) { - start = 0; - end = i; - ret = -ENOMEM; - goto free; - } - } - - read_lock_irqsave(&tasklist_lock, flags); - do_each_thread(g, t) { - if (start == end) { - ret = -EAGAIN; - goto unlock; - } +} - if (t->ret_stack == NULL) { - atomic_set(&t->tracing_graph_pause, 0); - atomic_set(&t->trace_overrun, 0); - t->curr_ret_stack = -1; - /* Make sure the tasks see the -1 first: */ - smp_wmb(); - t->ret_stack = ret_stack_list[start++]; - } - } while_each_thread(g, t); +#define lock_direct_mutex() do { } while (0) +#define unlock_direct_mutex() do { } while (0) -unlock: - read_unlock_irqrestore(&tasklist_lock, flags); -free: - for (i = start; i < end; i++) - kfree(ret_stack_list[i]); - return ret; -} +#endif /* CONFIG_DYNAMIC_FTRACE_WITH_DIRECT_CALLS */ -static void -ftrace_graph_probe_sched_switch(void *ignore, - struct task_struct *prev, struct task_struct *next) +/* + * Similar to register_ftrace_function, except we don't lock direct_mutex. + */ +static int register_ftrace_function_nolock(struct ftrace_ops *ops) { - unsigned long long timestamp; - int index; - - /* - * Does the user want to count the time a function was asleep. - * If so, do not update the time stamps. - */ - if (trace_flags & TRACE_ITER_SLEEP_TIME) - return; + int ret; - timestamp = trace_clock_local(); + ftrace_ops_init(ops); - prev->ftrace_timestamp = timestamp; + mutex_lock(&ftrace_lock); - /* only process tasks that we timestamped */ - if (!next->ftrace_timestamp) - return; + ret = ftrace_startup(ops, 0); - /* - * Update all the counters in next to make up for the - * time next was sleeping. - */ - timestamp -= next->ftrace_timestamp; + mutex_unlock(&ftrace_lock); - for (index = next->curr_ret_stack; index >= 0; index--) - next->ret_stack[index].calltime += timestamp; + return ret; } -/* Allocate a return stack for each task */ -static int start_graph_tracing(void) +/** + * register_ftrace_function - register a function for profiling + * @ops: ops structure that holds the function for profiling. + * + * Register a function to be called by all functions in the + * kernel. + * + * Note: @ops->func and all the functions it calls must be labeled + * with "notrace", otherwise it will go into a + * recursive loop. + */ +int register_ftrace_function(struct ftrace_ops *ops) { - struct ftrace_ret_stack **ret_stack_list; - int ret, cpu; - - ret_stack_list = kmalloc(FTRACE_RETSTACK_ALLOC_SIZE * - sizeof(struct ftrace_ret_stack *), - GFP_KERNEL); - - if (!ret_stack_list) - return -ENOMEM; - - /* The cpu_boot init_task->ret_stack will never be freed */ - for_each_online_cpu(cpu) { - if (!idle_task(cpu)->ret_stack) - ftrace_graph_init_idle_task(idle_task(cpu), cpu); - } + int ret; - do { - ret = alloc_retstack_tasklist(ret_stack_list); - } while (ret == -EAGAIN); + lock_direct_mutex(); + ret = prepare_direct_functions_for_ipmodify(ops); + if (ret < 0) + goto out_unlock; - if (!ret) { - ret = register_trace_sched_switch(ftrace_graph_probe_sched_switch, NULL); - if (ret) - pr_info("ftrace_graph: Couldn't activate tracepoint" - " probe to kernel_sched_switch\n"); - } + ret = register_ftrace_function_nolock(ops); - kfree(ret_stack_list); +out_unlock: + unlock_direct_mutex(); return ret; } +EXPORT_SYMBOL_GPL(register_ftrace_function); -/* - * Hibernation protection. - * The state of the current task is too much unstable during - * suspend/restore to disk. We want to protect against that. +/** + * unregister_ftrace_function - unregister a function for profiling. + * @ops: ops structure that holds the function to unregister + * + * Unregister a function that was added to be called by ftrace profiling. */ -static int -ftrace_suspend_notifier_call(struct notifier_block *bl, unsigned long state, - void *unused) +int unregister_ftrace_function(struct ftrace_ops *ops) { - switch (state) { - case PM_HIBERNATION_PREPARE: - pause_graph_tracing(); - break; + int ret; - case PM_POST_HIBERNATION: - unpause_graph_tracing(); - break; - } - return NOTIFY_DONE; + mutex_lock(&ftrace_lock); + ret = ftrace_shutdown(ops, 0); + mutex_unlock(&ftrace_lock); + + cleanup_direct_functions_after_ipmodify(ops); + return ret; } +EXPORT_SYMBOL_GPL(unregister_ftrace_function); -int register_ftrace_graph(trace_func_graph_ret_t retfunc, - trace_func_graph_ent_t entryfunc) +static int symbols_cmp(const void *a, const void *b) { - int ret = 0; + const char **str_a = (const char **) a; + const char **str_b = (const char **) b; - mutex_lock(&ftrace_lock); + return strcmp(*str_a, *str_b); +} - /* we currently allow only one tracer registered at a time */ - if (ftrace_graph_active) { - ret = -EBUSY; - goto out; - } +struct kallsyms_data { + unsigned long *addrs; + const char **syms; + size_t cnt; + size_t found; +}; - ftrace_suspend_notifier.notifier_call = ftrace_suspend_notifier_call; - register_pm_notifier(&ftrace_suspend_notifier); +/* This function gets called for all kernel and module symbols + * and returns 1 in case we resolved all the requested symbols, + * 0 otherwise. + */ +static int kallsyms_callback(void *data, const char *name, unsigned long addr) +{ + struct kallsyms_data *args = data; + const char **sym; + int idx; - ftrace_graph_active++; - ret = start_graph_tracing(); - if (ret) { - ftrace_graph_active--; - goto out; - } + sym = bsearch(&name, args->syms, args->cnt, sizeof(*args->syms), symbols_cmp); + if (!sym) + return 0; - ftrace_graph_return = retfunc; - ftrace_graph_entry = entryfunc; + idx = sym - args->syms; + if (args->addrs[idx]) + return 0; - ret = ftrace_startup(&global_ops, FTRACE_START_FUNC_RET); + if (!ftrace_location(addr)) + return 0; -out: - mutex_unlock(&ftrace_lock); - return ret; + args->addrs[idx] = addr; + args->found++; + return args->found == args->cnt ? 1 : 0; } -void unregister_ftrace_graph(void) +/** + * ftrace_lookup_symbols - Lookup addresses for array of symbols + * + * @sorted_syms: array of symbols pointers symbols to resolve, + * must be alphabetically sorted + * @cnt: number of symbols/addresses in @syms/@addrs arrays + * @addrs: array for storing resulting addresses + * + * This function looks up addresses for array of symbols provided in + * @syms array (must be alphabetically sorted) and stores them in + * @addrs array, which needs to be big enough to store at least @cnt + * addresses. + * + * Returns: 0 if all provided symbols are found, -ESRCH otherwise. + */ +int ftrace_lookup_symbols(const char **sorted_syms, size_t cnt, unsigned long *addrs) { - mutex_lock(&ftrace_lock); + struct kallsyms_data args; + int found_all; - if (unlikely(!ftrace_graph_active)) - goto out; - - ftrace_graph_active--; - ftrace_graph_return = (trace_func_graph_ret_t)ftrace_stub; - ftrace_graph_entry = ftrace_graph_entry_stub; - ftrace_shutdown(&global_ops, FTRACE_STOP_FUNC_RET); - unregister_pm_notifier(&ftrace_suspend_notifier); - unregister_trace_sched_switch(ftrace_graph_probe_sched_switch, NULL); + memset(addrs, 0, sizeof(*addrs) * cnt); + args.addrs = addrs; + args.syms = sorted_syms; + args.cnt = cnt; + args.found = 0; - out: - mutex_unlock(&ftrace_lock); + found_all = kallsyms_on_each_symbol(kallsyms_callback, &args); + if (found_all) + return 0; + found_all = module_kallsyms_on_each_symbol(NULL, kallsyms_callback, &args); + return found_all ? 0 : -ESRCH; } -static DEFINE_PER_CPU(struct ftrace_ret_stack *, idle_ret_stack); +#ifdef CONFIG_SYSCTL -static void -graph_init_task(struct task_struct *t, struct ftrace_ret_stack *ret_stack) +#ifdef CONFIG_DYNAMIC_FTRACE +static void ftrace_startup_sysctl(void) { - atomic_set(&t->tracing_graph_pause, 0); - atomic_set(&t->trace_overrun, 0); - t->ftrace_timestamp = 0; - /* make curr_ret_stack visible before we add the ret_stack */ - smp_wmb(); - t->ret_stack = ret_stack; + int command; + + if (unlikely(ftrace_disabled)) + return; + + /* Force update next time */ + saved_ftrace_func = NULL; + /* ftrace_start_up is true if we want ftrace running */ + if (ftrace_start_up) { + command = FTRACE_UPDATE_CALLS; + if (ftrace_graph_active) + command |= FTRACE_START_FUNC_RET; + ftrace_startup_enable(command); + } } -/* - * Allocate a return stack for the idle task. May be the first - * time through, or it may be done by CPU hotplug online. - */ -void ftrace_graph_init_idle_task(struct task_struct *t, int cpu) +static void ftrace_shutdown_sysctl(void) { - t->curr_ret_stack = -1; - /* - * The idle task has no parent, it either has its own - * stack or no stack at all. - */ - if (t->ret_stack) - WARN_ON(t->ret_stack != per_cpu(idle_ret_stack, cpu)); - - if (ftrace_graph_active) { - struct ftrace_ret_stack *ret_stack; - - ret_stack = per_cpu(idle_ret_stack, cpu); - if (!ret_stack) { - ret_stack = kmalloc(FTRACE_RETFUNC_DEPTH - * sizeof(struct ftrace_ret_stack), - GFP_KERNEL); - if (!ret_stack) - return; - per_cpu(idle_ret_stack, cpu) = ret_stack; - } - graph_init_task(t, ret_stack); + int command; + + if (unlikely(ftrace_disabled)) + return; + + /* ftrace_start_up is true if ftrace is running */ + if (ftrace_start_up) { + command = FTRACE_DISABLE_CALLS; + if (ftrace_graph_active) + command |= FTRACE_STOP_FUNC_RET; + ftrace_run_update_code(command); } } +#else +# define ftrace_startup_sysctl() do { } while (0) +# define ftrace_shutdown_sysctl() do { } while (0) +#endif /* CONFIG_DYNAMIC_FTRACE */ -/* Allocate a return stack for newly created task */ -void ftrace_graph_init_task(struct task_struct *t) +static bool is_permanent_ops_registered(void) { - /* Make sure we do not use the parent ret_stack */ - t->ret_stack = NULL; - t->curr_ret_stack = -1; + struct ftrace_ops *op; - if (ftrace_graph_active) { - struct ftrace_ret_stack *ret_stack; + do_for_each_ftrace_op(op, ftrace_ops_list) { + if (op->flags & FTRACE_OPS_FL_PERMANENT) + return true; + } while_for_each_ftrace_op(op); - ret_stack = kmalloc(FTRACE_RETFUNC_DEPTH - * sizeof(struct ftrace_ret_stack), - GFP_KERNEL); - if (!ret_stack) - return; - graph_init_task(t, ret_stack); - } + return false; } -void ftrace_graph_exit_task(struct task_struct *t) +static int +ftrace_enable_sysctl(const struct ctl_table *table, int write, + void *buffer, size_t *lenp, loff_t *ppos) { - struct ftrace_ret_stack *ret_stack = t->ret_stack; + int ret; + + guard(mutex)(&ftrace_lock); + + if (unlikely(ftrace_disabled)) + return -ENODEV; + + ret = proc_dointvec(table, write, buffer, lenp, ppos); + + if (ret || !write || (last_ftrace_enabled == !!ftrace_enabled)) + return ret; + + if (ftrace_enabled) { + + /* we are starting ftrace again */ + if (rcu_dereference_protected(ftrace_ops_list, + lockdep_is_held(&ftrace_lock)) != &ftrace_list_end) + update_ftrace_function(); + + ftrace_startup_sysctl(); + + } else { + if (is_permanent_ops_registered()) { + ftrace_enabled = true; + return -EBUSY; + } + + /* stopping ftrace calls (just send to ftrace_stub) */ + ftrace_trace_function = ftrace_stub; - t->ret_stack = NULL; - /* NULL must become visible to IRQs before we free it: */ - barrier(); + ftrace_shutdown_sysctl(); + } - kfree(ret_stack); + last_ftrace_enabled = !!ftrace_enabled; + return 0; } -void ftrace_graph_stop(void) +static const struct ctl_table ftrace_sysctls[] = { + { + .procname = "ftrace_enabled", + .data = &ftrace_enabled, + .maxlen = sizeof(int), + .mode = 0644, + .proc_handler = ftrace_enable_sysctl, + }, +}; + +static int __init ftrace_sysctl_init(void) { - ftrace_stop(); + register_sysctl_init("kernel", ftrace_sysctls); + return 0; } +late_initcall(ftrace_sysctl_init); #endif |