diff options
Diffstat (limited to 'kernel/trace')
| -rw-r--r-- | kernel/trace/bpf_trace.c | 8 | ||||
| -rw-r--r-- | kernel/trace/trace.c | 105 | ||||
| -rw-r--r-- | kernel/trace/trace.h | 8 | ||||
| -rw-r--r-- | kernel/trace/trace_branch.c | 4 | ||||
| -rw-r--r-- | kernel/trace/trace_events_hist.c | 14 | ||||
| -rw-r--r-- | kernel/trace/trace_stack.c | 85 |
6 files changed, 90 insertions, 134 deletions
diff --git a/kernel/trace/bpf_trace.c b/kernel/trace/bpf_trace.c index 8607aba1d882..b496ffdf5f36 100644 --- a/kernel/trace/bpf_trace.c +++ b/kernel/trace/bpf_trace.c @@ -14,6 +14,8 @@ #include <linux/syscalls.h> #include <linux/error-injection.h> +#include <asm/tlb.h> + #include "trace_probe.h" #include "trace.h" @@ -163,6 +165,10 @@ BPF_CALL_3(bpf_probe_write_user, void *, unsafe_ptr, const void *, src, * access_ok() should prevent writing to non-user memory, but in * some situations (nommu, temporary switch, etc) access_ok() does * not provide enough validation, hence the check on KERNEL_DS. + * + * nmi_uaccess_okay() ensures the probe is not run in an interim + * state, when the task or mm are switched. This is specifically + * required to prevent the use of temporary mm. */ if (unlikely(in_interrupt() || @@ -170,6 +176,8 @@ BPF_CALL_3(bpf_probe_write_user, void *, unsafe_ptr, const void *, src, return -EPERM; if (unlikely(uaccess_kernel())) return -EPERM; + if (unlikely(!nmi_uaccess_okay())) + return -EPERM; if (!access_ok(unsafe_ptr, size)) return -EPERM; diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c index ca1ee656d6d8..ec439999f387 100644 --- a/kernel/trace/trace.c +++ b/kernel/trace/trace.c @@ -159,6 +159,8 @@ static union trace_eval_map_item *trace_eval_maps; #endif /* CONFIG_TRACE_EVAL_MAP_FILE */ static int tracing_set_tracer(struct trace_array *tr, const char *buf); +static void ftrace_trace_userstack(struct ring_buffer *buffer, + unsigned long flags, int pc); #define MAX_TRACER_SIZE 100 static char bootup_tracer_buf[MAX_TRACER_SIZE] __initdata; @@ -2752,12 +2754,21 @@ trace_function(struct trace_array *tr, #ifdef CONFIG_STACKTRACE -#define FTRACE_STACK_MAX_ENTRIES (PAGE_SIZE / sizeof(unsigned long)) +/* Allow 4 levels of nesting: normal, softirq, irq, NMI */ +#define FTRACE_KSTACK_NESTING 4 + +#define FTRACE_KSTACK_ENTRIES (PAGE_SIZE / FTRACE_KSTACK_NESTING) + struct ftrace_stack { - unsigned long calls[FTRACE_STACK_MAX_ENTRIES]; + unsigned long calls[FTRACE_KSTACK_ENTRIES]; +}; + + +struct ftrace_stacks { + struct ftrace_stack stacks[FTRACE_KSTACK_NESTING]; }; -static DEFINE_PER_CPU(struct ftrace_stack, ftrace_stack); +static DEFINE_PER_CPU(struct ftrace_stacks, ftrace_stacks); static DEFINE_PER_CPU(int, ftrace_stack_reserve); static void __ftrace_trace_stack(struct ring_buffer *buffer, @@ -2766,13 +2777,10 @@ static void __ftrace_trace_stack(struct ring_buffer *buffer, { struct trace_event_call *call = &event_kernel_stack; struct ring_buffer_event *event; + unsigned int size, nr_entries; + struct ftrace_stack *fstack; struct stack_entry *entry; - struct stack_trace trace; - int use_stack; - int size = FTRACE_STACK_ENTRIES; - - trace.nr_entries = 0; - trace.skip = skip; + int stackidx; /* * Add one, for this function and the call to save_stack_trace() @@ -2780,7 +2788,7 @@ static void __ftrace_trace_stack(struct ring_buffer *buffer, */ #ifndef CONFIG_UNWINDER_ORC if (!regs) - trace.skip++; + skip++; #endif /* @@ -2791,53 +2799,40 @@ static void __ftrace_trace_stack(struct ring_buffer *buffer, */ preempt_disable_notrace(); - use_stack = __this_cpu_inc_return(ftrace_stack_reserve); + stackidx = __this_cpu_inc_return(ftrace_stack_reserve) - 1; + + /* This should never happen. If it does, yell once and skip */ + if (WARN_ON_ONCE(stackidx > FTRACE_KSTACK_NESTING)) + goto out; + /* - * We don't need any atomic variables, just a barrier. - * If an interrupt comes in, we don't care, because it would - * have exited and put the counter back to what we want. - * We just need a barrier to keep gcc from moving things - * around. + * The above __this_cpu_inc_return() is 'atomic' cpu local. An + * interrupt will either see the value pre increment or post + * increment. If the interrupt happens pre increment it will have + * restored the counter when it returns. We just need a barrier to + * keep gcc from moving things around. */ barrier(); - if (use_stack == 1) { - trace.entries = this_cpu_ptr(ftrace_stack.calls); - trace.max_entries = FTRACE_STACK_MAX_ENTRIES; - if (regs) - save_stack_trace_regs(regs, &trace); - else - save_stack_trace(&trace); - - if (trace.nr_entries > size) - size = trace.nr_entries; - } else - /* From now on, use_stack is a boolean */ - use_stack = 0; + fstack = this_cpu_ptr(ftrace_stacks.stacks) + stackidx; + size = ARRAY_SIZE(fstack->calls); - size *= sizeof(unsigned long); + if (regs) { + nr_entries = stack_trace_save_regs(regs, fstack->calls, + size, skip); + } else { + nr_entries = stack_trace_save(fstack->calls, size, skip); + } + size = nr_entries * sizeof(unsigned long); event = __trace_buffer_lock_reserve(buffer, TRACE_STACK, sizeof(*entry) + size, flags, pc); if (!event) goto out; entry = ring_buffer_event_data(event); - memset(&entry->caller, 0, size); - - if (use_stack) - memcpy(&entry->caller, trace.entries, - trace.nr_entries * sizeof(unsigned long)); - else { - trace.max_entries = FTRACE_STACK_ENTRIES; - trace.entries = entry->caller; - if (regs) - save_stack_trace_regs(regs, &trace); - else - save_stack_trace(&trace); - } - - entry->size = trace.nr_entries; + memcpy(&entry->caller, fstack->calls, size); + entry->size = nr_entries; if (!call_filter_check_discard(call, entry, buffer, event)) __buffer_unlock_commit(buffer, event); @@ -2907,15 +2902,15 @@ void trace_dump_stack(int skip) } EXPORT_SYMBOL_GPL(trace_dump_stack); +#ifdef CONFIG_USER_STACKTRACE_SUPPORT static DEFINE_PER_CPU(int, user_stack_count); -void +static void ftrace_trace_userstack(struct ring_buffer *buffer, unsigned long flags, int pc) { struct trace_event_call *call = &event_user_stack; struct ring_buffer_event *event; struct userstack_entry *entry; - struct stack_trace trace; if (!(global_trace.trace_flags & TRACE_ITER_USERSTACKTRACE)) return; @@ -2946,12 +2941,7 @@ ftrace_trace_userstack(struct ring_buffer *buffer, unsigned long flags, int pc) entry->tgid = current->tgid; memset(&entry->caller, 0, sizeof(entry->caller)); - trace.nr_entries = 0; - trace.max_entries = FTRACE_STACK_ENTRIES; - trace.skip = 0; - trace.entries = entry->caller; - - save_stack_trace_user(&trace); + stack_trace_save_user(entry->caller, FTRACE_STACK_ENTRIES); if (!call_filter_check_discard(call, entry, buffer, event)) __buffer_unlock_commit(buffer, event); @@ -2960,13 +2950,12 @@ ftrace_trace_userstack(struct ring_buffer *buffer, unsigned long flags, int pc) out: preempt_enable(); } - -#ifdef UNUSED -static void __trace_userstack(struct trace_array *tr, unsigned long flags) +#else /* CONFIG_USER_STACKTRACE_SUPPORT */ +static void ftrace_trace_userstack(struct ring_buffer *buffer, + unsigned long flags, int pc) { - ftrace_trace_userstack(tr, flags, preempt_count()); } -#endif /* UNUSED */ +#endif /* !CONFIG_USER_STACKTRACE_SUPPORT */ #endif /* CONFIG_STACKTRACE */ diff --git a/kernel/trace/trace.h b/kernel/trace/trace.h index d80cee49e0eb..639047b259d7 100644 --- a/kernel/trace/trace.h +++ b/kernel/trace/trace.h @@ -782,17 +782,9 @@ void update_max_tr_single(struct trace_array *tr, #endif /* CONFIG_TRACER_MAX_TRACE */ #ifdef CONFIG_STACKTRACE -void ftrace_trace_userstack(struct ring_buffer *buffer, unsigned long flags, - int pc); - void __trace_stack(struct trace_array *tr, unsigned long flags, int skip, int pc); #else -static inline void ftrace_trace_userstack(struct ring_buffer *buffer, - unsigned long flags, int pc) -{ -} - static inline void __trace_stack(struct trace_array *tr, unsigned long flags, int skip, int pc) { diff --git a/kernel/trace/trace_branch.c b/kernel/trace/trace_branch.c index 4ad967453b6f..3ea65cdff30d 100644 --- a/kernel/trace/trace_branch.c +++ b/kernel/trace/trace_branch.c @@ -205,6 +205,8 @@ void trace_likely_condition(struct ftrace_likely_data *f, int val, int expect) void ftrace_likely_update(struct ftrace_likely_data *f, int val, int expect, int is_constant) { + unsigned long flags = user_access_save(); + /* A constant is always correct */ if (is_constant) { f->constant++; @@ -223,6 +225,8 @@ void ftrace_likely_update(struct ftrace_likely_data *f, int val, f->data.correct++; else f->data.incorrect++; + + user_access_restore(flags); } EXPORT_SYMBOL(ftrace_likely_update); diff --git a/kernel/trace/trace_events_hist.c b/kernel/trace/trace_events_hist.c index 795aa2038377..a1d20421f4b0 100644 --- a/kernel/trace/trace_events_hist.c +++ b/kernel/trace/trace_events_hist.c @@ -5186,7 +5186,6 @@ static void event_hist_trigger(struct event_trigger_data *data, void *rec, u64 var_ref_vals[TRACING_MAP_VARS_MAX]; char compound_key[HIST_KEY_SIZE_MAX]; struct tracing_map_elt *elt = NULL; - struct stack_trace stacktrace; struct hist_field *key_field; u64 field_contents; void *key = NULL; @@ -5198,14 +5197,9 @@ static void event_hist_trigger(struct event_trigger_data *data, void *rec, key_field = hist_data->fields[i]; if (key_field->flags & HIST_FIELD_FL_STACKTRACE) { - stacktrace.max_entries = HIST_STACKTRACE_DEPTH; - stacktrace.entries = entries; - stacktrace.nr_entries = 0; - stacktrace.skip = HIST_STACKTRACE_SKIP; - - memset(stacktrace.entries, 0, HIST_STACKTRACE_SIZE); - save_stack_trace(&stacktrace); - + memset(entries, 0, HIST_STACKTRACE_SIZE); + stack_trace_save(entries, HIST_STACKTRACE_DEPTH, + HIST_STACKTRACE_SKIP); key = entries; } else { field_contents = key_field->fn(key_field, elt, rbe, rec); @@ -5246,7 +5240,7 @@ static void hist_trigger_stacktrace_print(struct seq_file *m, unsigned int i; for (i = 0; i < max_entries; i++) { - if (stacktrace_entries[i] == ULONG_MAX) + if (!stacktrace_entries[i]) return; seq_printf(m, "%*c", 1 + spaces, ' '); diff --git a/kernel/trace/trace_stack.c b/kernel/trace/trace_stack.c index eec648a0d673..5d16f73898db 100644 --- a/kernel/trace/trace_stack.c +++ b/kernel/trace/trace_stack.c @@ -18,44 +18,32 @@ #include "trace.h" -static unsigned long stack_dump_trace[STACK_TRACE_ENTRIES+1] = - { [0 ... (STACK_TRACE_ENTRIES)] = ULONG_MAX }; -unsigned stack_trace_index[STACK_TRACE_ENTRIES]; +#define STACK_TRACE_ENTRIES 500 -/* - * Reserve one entry for the passed in ip. This will allow - * us to remove most or all of the stack size overhead - * added by the stack tracer itself. - */ -struct stack_trace stack_trace_max = { - .max_entries = STACK_TRACE_ENTRIES - 1, - .entries = &stack_dump_trace[0], -}; +static unsigned long stack_dump_trace[STACK_TRACE_ENTRIES]; +static unsigned stack_trace_index[STACK_TRACE_ENTRIES]; -unsigned long stack_trace_max_size; -arch_spinlock_t stack_trace_max_lock = +static unsigned int stack_trace_nr_entries; +static unsigned long stack_trace_max_size; +static arch_spinlock_t stack_trace_max_lock = (arch_spinlock_t)__ARCH_SPIN_LOCK_UNLOCKED; DEFINE_PER_CPU(int, disable_stack_tracer); static DEFINE_MUTEX(stack_sysctl_mutex); int stack_tracer_enabled; -static int last_stack_tracer_enabled; -void stack_trace_print(void) +static void print_max_stack(void) { long i; int size; pr_emerg(" Depth Size Location (%d entries)\n" " ----- ---- --------\n", - stack_trace_max.nr_entries); + stack_trace_nr_entries); - for (i = 0; i < stack_trace_max.nr_entries; i++) { - if (stack_dump_trace[i] == ULONG_MAX) - break; - if (i+1 == stack_trace_max.nr_entries || - stack_dump_trace[i+1] == ULONG_MAX) + for (i = 0; i < stack_trace_nr_entries; i++) { + if (i + 1 == stack_trace_nr_entries) size = stack_trace_index[i]; else size = stack_trace_index[i] - stack_trace_index[i+1]; @@ -65,16 +53,7 @@ void stack_trace_print(void) } } -/* - * When arch-specific code overrides this function, the following - * data should be filled up, assuming stack_trace_max_lock is held to - * prevent concurrent updates. - * stack_trace_index[] - * stack_trace_max - * stack_trace_max_size - */ -void __weak -check_stack(unsigned long ip, unsigned long *stack) +static void check_stack(unsigned long ip, unsigned long *stack) { unsigned long this_size, flags; unsigned long *p, *top, *start; static int tracer_frame; @@ -110,13 +89,12 @@ check_stack(unsigned long ip, unsigned long *stack) stack_trace_max_size = this_size; - stack_trace_max.nr_entries = 0; - stack_trace_max.skip = 0; - - save_stack_trace(&stack_trace_max); + stack_trace_nr_entries = stack_trace_save(stack_dump_trace, + ARRAY_SIZE(stack_dump_trace) - 1, + 0); /* Skip over the overhead of the stack tracer itself */ - for (i = 0; i < stack_trace_max.nr_entries; i++) { + for (i = 0; i < stack_trace_nr_entries; i++) { if (stack_dump_trace[i] == ip) break; } @@ -125,7 +103,7 @@ check_stack(unsigned long ip, unsigned long *stack) * Some archs may not have the passed in ip in the dump. * If that happens, we need to show everything. */ - if (i == stack_trace_max.nr_entries) + if (i == stack_trace_nr_entries) i = 0; /* @@ -143,15 +121,13 @@ check_stack(unsigned long ip, unsigned long *stack) * loop will only happen once. This code only takes place * on a new max, so it is far from a fast path. */ - while (i < stack_trace_max.nr_entries) { + while (i < stack_trace_nr_entries) { int found = 0; stack_trace_index[x] = this_size; p = start; - for (; p < top && i < stack_trace_max.nr_entries; p++) { - if (stack_dump_trace[i] == ULONG_MAX) - break; + for (; p < top && i < stack_trace_nr_entries; p++) { /* * The READ_ONCE_NOCHECK is used to let KASAN know that * this is not a stack-out-of-bounds error. @@ -182,12 +158,10 @@ check_stack(unsigned long ip, unsigned long *stack) i++; } - stack_trace_max.nr_entries = x; - for (; x < i; x++) - stack_dump_trace[x] = ULONG_MAX; + stack_trace_nr_entries = x; if (task_stack_end_corrupted(current)) { - stack_trace_print(); + print_max_stack(); BUG(); } @@ -286,7 +260,7 @@ __next(struct seq_file *m, loff_t *pos) { long n = *pos - 1; - if (n >= stack_trace_max.nr_entries || stack_dump_trace[n] == ULONG_MAX) + if (n >= stack_trace_nr_entries) return NULL; m->private = (void *)n; @@ -350,7 +324,7 @@ static int t_show(struct seq_file *m, void *v) seq_printf(m, " Depth Size Location" " (%d entries)\n" " ----- ---- --------\n", - stack_trace_max.nr_entries); + stack_trace_nr_entries); if (!stack_tracer_enabled && !stack_trace_max_size) print_disabled(m); @@ -360,12 +334,10 @@ static int t_show(struct seq_file *m, void *v) i = *(long *)v; - if (i >= stack_trace_max.nr_entries || - stack_dump_trace[i] == ULONG_MAX) + if (i >= stack_trace_nr_entries) return 0; - if (i+1 == stack_trace_max.nr_entries || - stack_dump_trace[i+1] == ULONG_MAX) + if (i + 1 == stack_trace_nr_entries) size = stack_trace_index[i]; else size = stack_trace_index[i] - stack_trace_index[i+1]; @@ -422,23 +394,21 @@ stack_trace_sysctl(struct ctl_table *table, int write, void __user *buffer, size_t *lenp, loff_t *ppos) { + int was_enabled; int ret; mutex_lock(&stack_sysctl_mutex); + was_enabled = !!stack_tracer_enabled; ret = proc_dointvec(table, write, buffer, lenp, ppos); - if (ret || !write || - (last_stack_tracer_enabled == !!stack_tracer_enabled)) + if (ret || !write || (was_enabled == !!stack_tracer_enabled)) goto out; - last_stack_tracer_enabled = !!stack_tracer_enabled; - if (stack_tracer_enabled) register_ftrace_function(&trace_ops); else unregister_ftrace_function(&trace_ops); - out: mutex_unlock(&stack_sysctl_mutex); return ret; @@ -454,7 +424,6 @@ static __init int enable_stacktrace(char *str) strncpy(stack_trace_filter_buf, str + len, COMMAND_LINE_SIZE); stack_tracer_enabled = 1; - last_stack_tracer_enabled = 1; return 1; } __setup("stacktrace", enable_stacktrace); |