diff options
Diffstat (limited to 'include/linux/ftrace.h')
| -rw-r--r-- | include/linux/ftrace.h | 1159 |
1 files changed, 833 insertions, 326 deletions
diff --git a/include/linux/ftrace.h b/include/linux/ftrace.h index 9f15c0064c50..770f0dc993cc 100644 --- a/include/linux/ftrace.h +++ b/include/linux/ftrace.h @@ -1,12 +1,15 @@ +/* SPDX-License-Identifier: GPL-2.0 */ /* * Ftrace header. For implementation details beyond the random comments - * scattered below, see: Documentation/trace/ftrace-design.txt + * scattered below, see: Documentation/trace/ftrace-design.rst */ #ifndef _LINUX_FTRACE_H #define _LINUX_FTRACE_H +#include <linux/trace_recursion.h> #include <linux/trace_clock.h> +#include <linux/jump_label.h> #include <linux/kallsyms.h> #include <linux/linkage.h> #include <linux/bitops.h> @@ -28,49 +31,267 @@ #define ARCH_SUPPORTS_FTRACE_OPS 0 #endif +#ifdef CONFIG_TRACING +extern void ftrace_boot_snapshot(void); +#else +static inline void ftrace_boot_snapshot(void) { } +#endif + +struct ftrace_ops; +struct ftrace_regs; +struct dyn_ftrace; + +char *arch_ftrace_match_adjust(char *str, const char *search); + +#ifdef CONFIG_HAVE_FUNCTION_GRAPH_FREGS +unsigned long ftrace_return_to_handler(struct ftrace_regs *fregs); +#else +unsigned long ftrace_return_to_handler(unsigned long frame_pointer); +#endif + +#ifdef CONFIG_FUNCTION_TRACER /* * If the arch's mcount caller does not support all of ftrace's * features, then it must call an indirect function that - * does. Or at least does enough to prevent any unwelcomed side effects. + * does. Or at least does enough to prevent any unwelcome side effects. + * + * Also define the function prototype that these architectures use + * to call the ftrace_ops_list_func(). */ -#if !defined(CONFIG_HAVE_FUNCTION_TRACE_MCOUNT_TEST) || \ - !ARCH_SUPPORTS_FTRACE_OPS +#if !ARCH_SUPPORTS_FTRACE_OPS # define FTRACE_FORCE_LIST_FUNC 1 +void arch_ftrace_ops_list_func(unsigned long ip, unsigned long parent_ip); #else # define FTRACE_FORCE_LIST_FUNC 0 +void arch_ftrace_ops_list_func(unsigned long ip, unsigned long parent_ip, + struct ftrace_ops *op, struct ftrace_regs *fregs); #endif +extern const struct ftrace_ops ftrace_nop_ops; +extern const struct ftrace_ops ftrace_list_ops; +struct ftrace_ops *ftrace_find_unique_ops(struct dyn_ftrace *rec); +#endif /* CONFIG_FUNCTION_TRACER */ +/* Main tracing buffer and events set up */ +#ifdef CONFIG_TRACING +void trace_init(void); +void early_trace_init(void); +#else +static inline void trace_init(void) { } +static inline void early_trace_init(void) { } +#endif struct module; struct ftrace_hash; +#if defined(CONFIG_FUNCTION_TRACER) && defined(CONFIG_MODULES) && \ + defined(CONFIG_DYNAMIC_FTRACE) +int +ftrace_mod_address_lookup(unsigned long addr, unsigned long *size, + unsigned long *off, char **modname, char *sym); +#else +static inline int +ftrace_mod_address_lookup(unsigned long addr, unsigned long *size, + unsigned long *off, char **modname, char *sym) +{ + return 0; +} +#endif + +#if defined(CONFIG_FUNCTION_TRACER) && defined(CONFIG_DYNAMIC_FTRACE) +int ftrace_mod_get_kallsym(unsigned int symnum, unsigned long *value, + char *type, char *name, + char *module_name, int *exported); +#else +static inline int ftrace_mod_get_kallsym(unsigned int symnum, unsigned long *value, + char *type, char *name, + char *module_name, int *exported) +{ + return -1; +} +#endif + #ifdef CONFIG_FUNCTION_TRACER +#include <linux/ftrace_regs.h> + extern int ftrace_enabled; -extern int -ftrace_enable_sysctl(struct ctl_table *table, int write, - void __user *buffer, size_t *lenp, - loff_t *ppos); -struct ftrace_ops; +/** + * ftrace_regs - ftrace partial/optimal register set + * + * ftrace_regs represents a group of registers which is used at the + * function entry and exit. There are three types of registers. + * + * - Registers for passing the parameters to callee, including the stack + * pointer. (e.g. rcx, rdx, rdi, rsi, r8, r9 and rsp on x86_64) + * - Registers for passing the return values to caller. + * (e.g. rax and rdx on x86_64) + * - Registers for hooking the function call and return including the + * frame pointer (the frame pointer is architecture/config dependent) + * (e.g. rip, rbp and rsp for x86_64) + * + * Also, architecture dependent fields can be used for internal process. + * (e.g. orig_ax on x86_64) + * + * Basically, ftrace_regs stores the registers related to the context. + * On function entry, registers for function parameters and hooking the + * function call are stored, and on function exit, registers for function + * return value and frame pointers are stored. + * + * And also, it dpends on the context that which registers are restored + * from the ftrace_regs. + * On the function entry, those registers will be restored except for + * the stack pointer, so that user can change the function parameters + * and instruction pointer (e.g. live patching.) + * On the function exit, only registers which is used for return values + * are restored. + * + * NOTE: user *must not* access regs directly, only do it via APIs, because + * the member can be changed according to the architecture. + * This is why the structure is empty here, so that nothing accesses + * the ftrace_regs directly. + */ +struct ftrace_regs { + /* Nothing to see here, use the accessor functions! */ +}; + +#define ftrace_regs_size() sizeof(struct __arch_ftrace_regs) + +#ifndef CONFIG_HAVE_DYNAMIC_FTRACE_WITH_ARGS +/* + * Architectures that define HAVE_DYNAMIC_FTRACE_WITH_ARGS must define their own + * arch_ftrace_get_regs() where it only returns pt_regs *if* it is fully + * populated. It should return NULL otherwise. + */ +static inline struct pt_regs *arch_ftrace_get_regs(struct ftrace_regs *fregs) +{ + return &arch_ftrace_regs(fregs)->regs; +} + +/* + * ftrace_regs_set_instruction_pointer() is to be defined by the architecture + * if to allow setting of the instruction pointer from the ftrace_regs when + * HAVE_DYNAMIC_FTRACE_WITH_ARGS is set and it supports live kernel patching. + */ +#define ftrace_regs_set_instruction_pointer(fregs, ip) do { } while (0) +#endif /* CONFIG_HAVE_DYNAMIC_FTRACE_WITH_ARGS */ + +#ifdef CONFIG_HAVE_FTRACE_REGS_HAVING_PT_REGS + +static_assert(sizeof(struct pt_regs) == ftrace_regs_size()); + +#endif /* CONFIG_HAVE_FTRACE_REGS_HAVING_PT_REGS */ + +static __always_inline struct pt_regs *ftrace_get_regs(struct ftrace_regs *fregs) +{ + if (!fregs) + return NULL; + + return arch_ftrace_get_regs(fregs); +} + +#if !defined(CONFIG_HAVE_DYNAMIC_FTRACE_WITH_ARGS) || \ + defined(CONFIG_HAVE_FTRACE_REGS_HAVING_PT_REGS) + +#ifndef arch_ftrace_partial_regs +#define arch_ftrace_partial_regs(regs) do {} while (0) +#endif + +static __always_inline struct pt_regs * +ftrace_partial_regs(struct ftrace_regs *fregs, struct pt_regs *regs) +{ + /* + * If CONFIG_HAVE_FTRACE_REGS_HAVING_PT_REGS=y, ftrace_regs memory + * layout is including pt_regs. So always returns that address. + * Since arch_ftrace_get_regs() will check some members and may return + * NULL, we can not use it. + */ + regs = &arch_ftrace_regs(fregs)->regs; + + /* Allow arch specific updates to regs. */ + arch_ftrace_partial_regs(regs); + return regs; +} + +#endif /* !CONFIG_HAVE_DYNAMIC_FTRACE_WITH_ARGS || CONFIG_HAVE_FTRACE_REGS_HAVING_PT_REGS */ + +#ifdef CONFIG_HAVE_DYNAMIC_FTRACE_WITH_ARGS + +/* + * Please define arch dependent pt_regs which compatible to the + * perf_arch_fetch_caller_regs() but based on ftrace_regs. + * This requires + * - user_mode(_regs) returns false (always kernel mode). + * - able to use the _regs for stack trace. + */ +#ifndef arch_ftrace_fill_perf_regs +/* As same as perf_arch_fetch_caller_regs(), do nothing by default */ +#define arch_ftrace_fill_perf_regs(fregs, _regs) do {} while (0) +#endif + +static __always_inline struct pt_regs * +ftrace_fill_perf_regs(struct ftrace_regs *fregs, struct pt_regs *regs) +{ + arch_ftrace_fill_perf_regs(fregs, regs); + return regs; +} + +#else /* !CONFIG_HAVE_DYNAMIC_FTRACE_WITH_ARGS */ + +static __always_inline struct pt_regs * +ftrace_fill_perf_regs(struct ftrace_regs *fregs, struct pt_regs *regs) +{ + return &arch_ftrace_regs(fregs)->regs; +} + +#endif + +/* + * When true, the ftrace_regs_{get,set}_*() functions may be used on fregs. + * Note: this can be true even when ftrace_get_regs() cannot provide a pt_regs. + */ +static __always_inline bool ftrace_regs_has_args(struct ftrace_regs *fregs) +{ + if (IS_ENABLED(CONFIG_HAVE_DYNAMIC_FTRACE_WITH_ARGS)) + return true; + + return ftrace_get_regs(fregs) != NULL; +} + +#ifdef CONFIG_HAVE_REGS_AND_STACK_ACCESS_API +static __always_inline unsigned long +ftrace_regs_get_kernel_stack_nth(struct ftrace_regs *fregs, unsigned int nth) +{ + unsigned long *stackp; + + stackp = (unsigned long *)ftrace_regs_get_stack_pointer(fregs); + if (((unsigned long)(stackp + nth) & ~(THREAD_SIZE - 1)) == + ((unsigned long)stackp & ~(THREAD_SIZE - 1))) + return *(stackp + nth); + + return 0; +} +#else /* !CONFIG_HAVE_REGS_AND_STACK_ACCESS_API */ +#define ftrace_regs_get_kernel_stack_nth(fregs, nth) (0L) +#endif /* CONFIG_HAVE_REGS_AND_STACK_ACCESS_API */ typedef void (*ftrace_func_t)(unsigned long ip, unsigned long parent_ip, - struct ftrace_ops *op, struct pt_regs *regs); + struct ftrace_ops *op, struct ftrace_regs *fregs); + +ftrace_func_t ftrace_ops_get_func(struct ftrace_ops *ops); /* * FTRACE_OPS_FL_* bits denote the state of ftrace_ops struct and are * set in the flags member. + * CONTROL, SAVE_REGS, SAVE_REGS_IF_SUPPORTED, RECURSION, STUB and + * IPMODIFY are a kind of attribute flags which can be set only before + * registering the ftrace_ops, and can not be modified while registered. + * Changing those attribute flags after registering ftrace_ops will + * cause unexpected results. * * ENABLED - set/unset when ftrace_ops is registered/unregistered - * GLOBAL - set manualy by ftrace_ops user to denote the ftrace_ops - * is part of the global tracers sharing the same filter - * via set_ftrace_* debugfs files. * DYNAMIC - set when ftrace_ops is registered to denote dynamically * allocated ftrace_ops which need special care - * CONTROL - set manualy by ftrace_ops user to denote the ftrace_ops - * could be controled by following calls: - * ftrace_function_local_enable - * ftrace_function_local_disable * SAVE_REGS - The ftrace_ops wants regs saved at each function called * and passed to the callback. If this flag is set, but the * architecture does not support passing regs @@ -85,39 +306,178 @@ typedef void (*ftrace_func_t)(unsigned long ip, unsigned long parent_ip, * passing regs to the handler. * Note, if this flag is set, the SAVE_REGS flag will automatically * get set upon registering the ftrace_ops, if the arch supports it. - * RECURSION_SAFE - The ftrace_ops can set this to tell the ftrace infrastructure - * that the call back has its own recursion protection. If it does - * not set this, then the ftrace infrastructure will add recursion - * protection for the caller. + * RECURSION - The ftrace_ops can set this to tell the ftrace infrastructure + * that the call back needs recursion protection. If it does + * not set this, then the ftrace infrastructure will assume + * that the callback can handle recursion on its own. * STUB - The ftrace_ops is just a place holder. * INITIALIZED - The ftrace_ops has already been initialized (first use time * register_ftrace_function() is called, it will initialized the ops) + * DELETED - The ops are being deleted, do not let them be registered again. + * ADDING - The ops is in the process of being added. + * REMOVING - The ops is in the process of being removed. + * MODIFYING - The ops is in the process of changing its filter functions. + * ALLOC_TRAMP - A dynamic trampoline was allocated by the core code. + * The arch specific code sets this flag when it allocated a + * trampoline. This lets the arch know that it can update the + * trampoline in case the callback function changes. + * The ftrace_ops trampoline can be set by the ftrace users, and + * in such cases the arch must not modify it. Only the arch ftrace + * core code should set this flag. + * IPMODIFY - The ops can modify the IP register. This can only be set with + * SAVE_REGS. If another ops with this flag set is already registered + * for any of the functions that this ops will be registered for, then + * this ops will fail to register or set_filter_ip. + * PID - Is affected by set_ftrace_pid (allows filtering on those pids) + * RCU - Set when the ops can only be called when RCU is watching. + * TRACE_ARRAY - The ops->private points to a trace_array descriptor. + * PERMANENT - Set when the ops is permanent and should not be affected by + * ftrace_enabled. + * DIRECT - Used by the direct ftrace_ops helper for direct functions + * (internal ftrace only, should not be used by others) + * SUBOP - Is controlled by another op in field managed. + * GRAPH - Is a component of the fgraph_ops structure */ enum { - FTRACE_OPS_FL_ENABLED = 1 << 0, - FTRACE_OPS_FL_GLOBAL = 1 << 1, - FTRACE_OPS_FL_DYNAMIC = 1 << 2, - FTRACE_OPS_FL_CONTROL = 1 << 3, - FTRACE_OPS_FL_SAVE_REGS = 1 << 4, - FTRACE_OPS_FL_SAVE_REGS_IF_SUPPORTED = 1 << 5, - FTRACE_OPS_FL_RECURSION_SAFE = 1 << 6, - FTRACE_OPS_FL_STUB = 1 << 7, - FTRACE_OPS_FL_INITIALIZED = 1 << 8, + FTRACE_OPS_FL_ENABLED = BIT(0), + FTRACE_OPS_FL_DYNAMIC = BIT(1), + FTRACE_OPS_FL_SAVE_REGS = BIT(2), + FTRACE_OPS_FL_SAVE_REGS_IF_SUPPORTED = BIT(3), + FTRACE_OPS_FL_RECURSION = BIT(4), + FTRACE_OPS_FL_STUB = BIT(5), + FTRACE_OPS_FL_INITIALIZED = BIT(6), + FTRACE_OPS_FL_DELETED = BIT(7), + FTRACE_OPS_FL_ADDING = BIT(8), + FTRACE_OPS_FL_REMOVING = BIT(9), + FTRACE_OPS_FL_MODIFYING = BIT(10), + FTRACE_OPS_FL_ALLOC_TRAMP = BIT(11), + FTRACE_OPS_FL_IPMODIFY = BIT(12), + FTRACE_OPS_FL_PID = BIT(13), + FTRACE_OPS_FL_RCU = BIT(14), + FTRACE_OPS_FL_TRACE_ARRAY = BIT(15), + FTRACE_OPS_FL_PERMANENT = BIT(16), + FTRACE_OPS_FL_DIRECT = BIT(17), + FTRACE_OPS_FL_SUBOP = BIT(18), + FTRACE_OPS_FL_GRAPH = BIT(19), + FTRACE_OPS_FL_JMP = BIT(20), }; +#ifndef CONFIG_DYNAMIC_FTRACE_WITH_ARGS +#define FTRACE_OPS_FL_SAVE_ARGS FTRACE_OPS_FL_SAVE_REGS +#else +#define FTRACE_OPS_FL_SAVE_ARGS 0 +#endif + +/* + * FTRACE_OPS_CMD_* commands allow the ftrace core logic to request changes + * to a ftrace_ops. Note, the requests may fail. + * + * ENABLE_SHARE_IPMODIFY_SELF - enable a DIRECT ops to work on the same + * function as an ops with IPMODIFY. Called + * when the DIRECT ops is being registered. + * This is called with both direct_mutex and + * ftrace_lock are locked. + * + * ENABLE_SHARE_IPMODIFY_PEER - enable a DIRECT ops to work on the same + * function as an ops with IPMODIFY. Called + * when the other ops (the one with IPMODIFY) + * is being registered. + * This is called with direct_mutex locked. + * + * DISABLE_SHARE_IPMODIFY_PEER - disable a DIRECT ops to work on the same + * function as an ops with IPMODIFY. Called + * when the other ops (the one with IPMODIFY) + * is being unregistered. + * This is called with direct_mutex locked. + */ +enum ftrace_ops_cmd { + FTRACE_OPS_CMD_ENABLE_SHARE_IPMODIFY_SELF, + FTRACE_OPS_CMD_ENABLE_SHARE_IPMODIFY_PEER, + FTRACE_OPS_CMD_DISABLE_SHARE_IPMODIFY_PEER, +}; + +/* + * For most ftrace_ops_cmd, + * Returns: + * 0 - Success. + * Negative on failure. The return value is dependent on the + * callback. + */ +typedef int (*ftrace_ops_func_t)(struct ftrace_ops *op, enum ftrace_ops_cmd cmd); + +#ifdef CONFIG_DYNAMIC_FTRACE +/* The hash used to know what functions callbacks trace */ +struct ftrace_ops_hash { + struct ftrace_hash __rcu *notrace_hash; + struct ftrace_hash __rcu *filter_hash; + struct mutex regex_lock; +}; + +void ftrace_free_init_mem(void); +void ftrace_free_mem(struct module *mod, void *start, void *end); +#else +static inline void ftrace_free_init_mem(void) +{ + ftrace_boot_snapshot(); +} +static inline void ftrace_free_mem(struct module *mod, void *start, void *end) { } +#endif + +/* + * Note, ftrace_ops can be referenced outside of RCU protection, unless + * the RCU flag is set. If ftrace_ops is allocated and not part of kernel + * core data, the unregistering of it will perform a scheduling on all CPUs + * to make sure that there are no more users. Depending on the load of the + * system that may take a bit of time. + * + * Any private data added must also take care not to be freed and if private + * data is added to a ftrace_ops that is in core code, the user of the + * ftrace_ops must perform a schedule_on_each_cpu() before freeing it. + */ struct ftrace_ops { ftrace_func_t func; - struct ftrace_ops *next; + struct ftrace_ops __rcu *next; unsigned long flags; - int __percpu *disabled; + void *private; + ftrace_func_t saved_func; #ifdef CONFIG_DYNAMIC_FTRACE - struct ftrace_hash *notrace_hash; - struct ftrace_hash *filter_hash; - struct mutex regex_lock; + struct ftrace_ops_hash local_hash; + struct ftrace_ops_hash *func_hash; + struct ftrace_ops_hash old_hash; + unsigned long trampoline; + unsigned long trampoline_size; + struct list_head list; + struct list_head subop_list; + ftrace_ops_func_t ops_func; + struct ftrace_ops *managed; +#ifdef CONFIG_DYNAMIC_FTRACE_WITH_DIRECT_CALLS + unsigned long direct_call; +#endif #endif }; -extern int function_trace_stop; +extern struct ftrace_ops __rcu *ftrace_ops_list; +extern struct ftrace_ops ftrace_list_end; + +/* + * Traverse the ftrace_ops_list, invoking all entries. The reason that we + * can use rcu_dereference_raw_check() 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_check() calls are needed to handle + * concurrent insertions into the ftrace_ops_list. + * + * Silly Alpha and silly pointer-speculation compiler optimizations! + */ +#define do_for_each_ftrace_op(op, list) \ + op = rcu_dereference_raw_check(list); \ + do + +/* + * Optimized for just a single item in the list (as that is the normal case). + */ +#define while_for_each_ftrace_op(op) \ + while (likely(op = rcu_dereference_raw_check((op)->next)) && \ + unlikely((op) != &ftrace_list_end)) /* * Type of the current tracing. @@ -130,32 +490,6 @@ enum ftrace_tracing_type_t { /* Current tracing type, default is FTRACE_TYPE_ENTER */ extern enum ftrace_tracing_type_t ftrace_tracing_type; -/** - * ftrace_stop - stop function tracer. - * - * A quick way to stop the function tracer. Note this an on off switch, - * it is not something that is recursive like preempt_disable. - * This does not disable the calling of mcount, it only stops the - * calling of functions from mcount. - */ -static inline void ftrace_stop(void) -{ - function_trace_stop = 1; -} - -/** - * ftrace_start - start the function tracer. - * - * This function is the inverse of ftrace_stop. This does not enable - * the function tracing if the function tracer is disabled. This only - * sets the function tracer flag to continue calling the functions - * from mcount. - */ -static inline void ftrace_start(void) -{ - function_trace_stop = 0; -} - /* * The ftrace_ops must be a static and should also * be read_mostly. These functions do modify read_mostly variables @@ -165,129 +499,214 @@ static inline void ftrace_start(void) */ int register_ftrace_function(struct ftrace_ops *ops); int unregister_ftrace_function(struct ftrace_ops *ops); -void clear_ftrace_function(void); -/** - * ftrace_function_local_enable - enable controlled ftrace_ops on current cpu - * - * This function enables tracing on current cpu by decreasing - * the per cpu control variable. - * It must be called with preemption disabled and only on ftrace_ops - * registered with FTRACE_OPS_FL_CONTROL. If called without preemption - * disabled, this_cpu_ptr will complain when CONFIG_DEBUG_PREEMPT is enabled. +extern void ftrace_stub(unsigned long a0, unsigned long a1, + struct ftrace_ops *op, struct ftrace_regs *fregs); + + +int ftrace_lookup_symbols(const char **sorted_syms, size_t cnt, unsigned long *addrs); +#else /* !CONFIG_FUNCTION_TRACER */ +/* + * (un)register_ftrace_function must be a macro since the ops parameter + * must not be evaluated. */ -static inline void ftrace_function_local_enable(struct ftrace_ops *ops) +#define register_ftrace_function(ops) ({ 0; }) +#define unregister_ftrace_function(ops) ({ 0; }) +static inline void ftrace_kill(void) { } +static inline void ftrace_free_init_mem(void) { } +static inline void ftrace_free_mem(struct module *mod, void *start, void *end) { } +static inline int ftrace_lookup_symbols(const char **sorted_syms, size_t cnt, unsigned long *addrs) { - if (WARN_ON_ONCE(!(ops->flags & FTRACE_OPS_FL_CONTROL))) - return; + return -EOPNOTSUPP; +} +#endif /* CONFIG_FUNCTION_TRACER */ + +struct ftrace_func_entry { + struct hlist_node hlist; + unsigned long ip; + unsigned long direct; /* for direct lookup only */ +}; + +#ifdef CONFIG_DYNAMIC_FTRACE_WITH_DIRECT_CALLS +unsigned long ftrace_find_rec_direct(unsigned long ip); +int register_ftrace_direct(struct ftrace_ops *ops, unsigned long addr); +int unregister_ftrace_direct(struct ftrace_ops *ops, unsigned long addr, + bool free_filters); +int modify_ftrace_direct(struct ftrace_ops *ops, unsigned long addr); +int modify_ftrace_direct_nolock(struct ftrace_ops *ops, unsigned long addr); + +void ftrace_stub_direct_tramp(void); - (*this_cpu_ptr(ops->disabled))--; +#else +struct ftrace_ops; +static inline unsigned long ftrace_find_rec_direct(unsigned long ip) +{ + return 0; +} +static inline int register_ftrace_direct(struct ftrace_ops *ops, unsigned long addr) +{ + return -ENODEV; +} +static inline int unregister_ftrace_direct(struct ftrace_ops *ops, unsigned long addr, + bool free_filters) +{ + return -ENODEV; +} +static inline int modify_ftrace_direct(struct ftrace_ops *ops, unsigned long addr) +{ + return -ENODEV; +} +static inline int modify_ftrace_direct_nolock(struct ftrace_ops *ops, unsigned long addr) +{ + return -ENODEV; } -/** - * ftrace_function_local_disable - enable controlled ftrace_ops on current cpu +/* + * This must be implemented by the architecture. + * It is the way the ftrace direct_ops helper, when called + * via ftrace (because there's other callbacks besides the + * direct call), can inform the architecture's trampoline that this + * routine has a direct caller, and what the caller is. * - * This function enables tracing on current cpu by decreasing - * the per cpu control variable. - * It must be called with preemption disabled and only on ftrace_ops - * registered with FTRACE_OPS_FL_CONTROL. If called without preemption - * disabled, this_cpu_ptr will complain when CONFIG_DEBUG_PREEMPT is enabled. + * For example, in x86, it returns the direct caller + * callback function via the regs->orig_ax parameter. + * Then in the ftrace trampoline, if this is set, it makes + * the return from the trampoline jump to the direct caller + * instead of going back to the function it just traced. */ -static inline void ftrace_function_local_disable(struct ftrace_ops *ops) +static inline void arch_ftrace_set_direct_caller(struct ftrace_regs *fregs, + unsigned long addr) { } +#endif /* CONFIG_DYNAMIC_FTRACE_WITH_DIRECT_CALLS */ + +#ifdef CONFIG_DYNAMIC_FTRACE_WITH_JMP +static inline bool ftrace_is_jmp(unsigned long addr) +{ + return addr & 1; +} + +static inline unsigned long ftrace_jmp_set(unsigned long addr) { - if (WARN_ON_ONCE(!(ops->flags & FTRACE_OPS_FL_CONTROL))) - return; + return addr | 1UL; +} - (*this_cpu_ptr(ops->disabled))++; +static inline unsigned long ftrace_jmp_get(unsigned long addr) +{ + return addr & ~1UL; +} +#else +static inline bool ftrace_is_jmp(unsigned long addr) +{ + return false; } +static inline unsigned long ftrace_jmp_set(unsigned long addr) +{ + return addr; +} + +static inline unsigned long ftrace_jmp_get(unsigned long addr) +{ + return addr; +} +#endif /* CONFIG_DYNAMIC_FTRACE_WITH_JMP */ + +#ifdef CONFIG_STACK_TRACER + +int stack_trace_sysctl(const struct ctl_table *table, int write, void *buffer, + size_t *lenp, loff_t *ppos); + +/* DO NOT MODIFY THIS VARIABLE DIRECTLY! */ +DECLARE_PER_CPU(int, disable_stack_tracer); + /** - * ftrace_function_local_disabled - returns ftrace_ops disabled value - * on current cpu + * stack_tracer_disable - temporarily disable the stack tracer * - * This function returns value of ftrace_ops::disabled on current cpu. - * It must be called with preemption disabled and only on ftrace_ops - * registered with FTRACE_OPS_FL_CONTROL. If called without preemption - * disabled, this_cpu_ptr will complain when CONFIG_DEBUG_PREEMPT is enabled. + * There's a few locations (namely in RCU) where stack tracing + * cannot be executed. This function is used to disable stack + * tracing during those critical sections. + * + * This function must be called with preemption or interrupts + * disabled and stack_tracer_enable() must be called shortly after + * while preemption or interrupts are still disabled. */ -static inline int ftrace_function_local_disabled(struct ftrace_ops *ops) +static inline void stack_tracer_disable(void) { - WARN_ON_ONCE(!(ops->flags & FTRACE_OPS_FL_CONTROL)); - return *this_cpu_ptr(ops->disabled); + /* Preemption or interrupts must be disabled */ + if (IS_ENABLED(CONFIG_DEBUG_PREEMPT)) + WARN_ON_ONCE(!preempt_count() || !irqs_disabled()); + this_cpu_inc(disable_stack_tracer); } -extern void ftrace_stub(unsigned long a0, unsigned long a1, - struct ftrace_ops *op, struct pt_regs *regs); - -#else /* !CONFIG_FUNCTION_TRACER */ -/* - * (un)register_ftrace_function must be a macro since the ops parameter - * must not be evaluated. +/** + * stack_tracer_enable - re-enable the stack tracer + * + * After stack_tracer_disable() is called, stack_tracer_enable() + * must be called shortly afterward. */ -#define register_ftrace_function(ops) ({ 0; }) -#define unregister_ftrace_function(ops) ({ 0; }) -static inline int ftrace_nr_registered_ops(void) +static inline void stack_tracer_enable(void) { - return 0; + if (IS_ENABLED(CONFIG_DEBUG_PREEMPT)) + WARN_ON_ONCE(!preempt_count() || !irqs_disabled()); + this_cpu_dec(disable_stack_tracer); } -static inline void clear_ftrace_function(void) { } -static inline void ftrace_kill(void) { } -static inline void ftrace_stop(void) { } -static inline void ftrace_start(void) { } -#endif /* CONFIG_FUNCTION_TRACER */ - -#ifdef CONFIG_STACK_TRACER -extern int stack_tracer_enabled; -int -stack_trace_sysctl(struct ctl_table *table, int write, - void __user *buffer, size_t *lenp, - loff_t *ppos); +#else +static inline void stack_tracer_disable(void) { } +static inline void stack_tracer_enable(void) { } #endif -struct ftrace_func_command { - struct list_head list; - char *name; - int (*func)(struct ftrace_hash *hash, - char *func, char *cmd, - char *params, int enable); +enum { + FTRACE_UPDATE_CALLS = (1 << 0), + FTRACE_DISABLE_CALLS = (1 << 1), + FTRACE_UPDATE_TRACE_FUNC = (1 << 2), + FTRACE_START_FUNC_RET = (1 << 3), + FTRACE_STOP_FUNC_RET = (1 << 4), + FTRACE_MAY_SLEEP = (1 << 5), }; -#ifdef CONFIG_DYNAMIC_FTRACE +/* Arches can override ftrace_get_symaddr() to convert fentry_ip to symaddr. */ +#ifndef ftrace_get_symaddr +/** + * ftrace_get_symaddr - return the symbol address from fentry_ip + * @fentry_ip: the address of ftrace location + * + * Get the symbol address from @fentry_ip (fast path). If there is no fast + * search path, this returns 0. + * User may need to use kallsyms API to find the symbol address. + */ +#define ftrace_get_symaddr(fentry_ip) (0) +#endif -int ftrace_arch_code_modify_prepare(void); -int ftrace_arch_code_modify_post_process(void); +void ftrace_sync_ipi(void *data); -void ftrace_bug(int err, unsigned long ip); +#ifdef CONFIG_DYNAMIC_FTRACE -struct seq_file; +void ftrace_arch_code_modify_prepare(void); +void ftrace_arch_code_modify_post_process(void); -struct ftrace_probe_ops { - void (*func)(unsigned long ip, - unsigned long parent_ip, - void **data); - int (*init)(struct ftrace_probe_ops *ops, - unsigned long ip, void **data); - void (*free)(struct ftrace_probe_ops *ops, - unsigned long ip, void **data); - int (*print)(struct seq_file *m, - unsigned long ip, - struct ftrace_probe_ops *ops, - void *data); +enum ftrace_bug_type { + FTRACE_BUG_UNKNOWN, + FTRACE_BUG_INIT, + FTRACE_BUG_NOP, + FTRACE_BUG_CALL, + FTRACE_BUG_UPDATE, }; +extern enum ftrace_bug_type ftrace_bug_type; -extern int -register_ftrace_function_probe(char *glob, struct ftrace_probe_ops *ops, - void *data); -extern void -unregister_ftrace_function_probe(char *glob, struct ftrace_probe_ops *ops, - void *data); -extern void -unregister_ftrace_function_probe_func(char *glob, struct ftrace_probe_ops *ops); -extern void unregister_ftrace_function_probe_all(char *glob); +/* + * Archs can set this to point to a variable that holds the value that was + * expected at the call site before calling ftrace_bug(). + */ +extern const void *ftrace_expected; -extern int ftrace_text_reserved(void *start, void *end); +void ftrace_bug(int err, struct dyn_ftrace *rec); -extern int ftrace_nr_registered_ops(void); +struct seq_file; + +extern int ftrace_text_reserved(const void *start, const void *end); + +struct ftrace_ops *ftrace_ops_trampoline(unsigned long addr); + +bool is_ftrace_trampoline(unsigned long addr); /* * The dyn_ftrace record's flags field is split into two parts. @@ -299,34 +718,51 @@ extern int ftrace_nr_registered_ops(void); * ENABLED - the function is being traced * REGS - the record wants the function to save regs * REGS_EN - the function is set up to save regs. + * IPMODIFY - the record allows for the IP address to be changed. + * DISABLED - the record is not ready to be touched yet + * DIRECT - there is a direct function to call + * CALL_OPS - the record can use callsite-specific ops + * CALL_OPS_EN - the function is set up to use callsite-specific ops + * TOUCHED - A callback was added since boot up + * MODIFIED - The function had IPMODIFY or DIRECT attached to it * * When a new ftrace_ops is registered and wants a function to save - * pt_regs, the rec->flag REGS is set. When the function has been + * pt_regs, the rec->flags REGS is set. When the function has been * set up to save regs, the REG_EN flag is set. Once a function * starts saving regs it will do so until all ftrace_ops are removed * from tracing that function. */ enum { - FTRACE_FL_ENABLED = (1UL << 29), + FTRACE_FL_ENABLED = (1UL << 31), FTRACE_FL_REGS = (1UL << 30), - FTRACE_FL_REGS_EN = (1UL << 31) + FTRACE_FL_REGS_EN = (1UL << 29), + FTRACE_FL_TRAMP = (1UL << 28), + FTRACE_FL_TRAMP_EN = (1UL << 27), + FTRACE_FL_IPMODIFY = (1UL << 26), + FTRACE_FL_DISABLED = (1UL << 25), + FTRACE_FL_DIRECT = (1UL << 24), + FTRACE_FL_DIRECT_EN = (1UL << 23), + FTRACE_FL_CALL_OPS = (1UL << 22), + FTRACE_FL_CALL_OPS_EN = (1UL << 21), + FTRACE_FL_TOUCHED = (1UL << 20), + FTRACE_FL_MODIFIED = (1UL << 19), }; -#define FTRACE_FL_MASK (0x7UL << 29) -#define FTRACE_REF_MAX ((1UL << 29) - 1) +#define FTRACE_REF_MAX_SHIFT 19 +#define FTRACE_REF_MAX ((1UL << FTRACE_REF_MAX_SHIFT) - 1) + +#define ftrace_rec_count(rec) ((rec)->flags & FTRACE_REF_MAX) struct dyn_ftrace { - union { - unsigned long ip; /* address of mcount call-site */ - struct dyn_ftrace *freelist; - }; + unsigned long ip; /* address of mcount call-site */ unsigned long flags; - struct dyn_arch_ftrace arch; + struct dyn_arch_ftrace arch; }; -int ftrace_force_update(void); int ftrace_set_filter_ip(struct ftrace_ops *ops, unsigned long ip, int remove, int reset); +int ftrace_set_filter_ips(struct ftrace_ops *ops, unsigned long *ips, + unsigned int cnt, int remove, int reset); int ftrace_set_filter(struct ftrace_ops *ops, unsigned char *buf, int len, int reset); int ftrace_set_notrace(struct ftrace_ops *ops, unsigned char *buf, @@ -334,17 +770,7 @@ int ftrace_set_notrace(struct ftrace_ops *ops, unsigned char *buf, void ftrace_set_global_filter(unsigned char *buf, int len, int reset); void ftrace_set_global_notrace(unsigned char *buf, int len, int reset); void ftrace_free_filter(struct ftrace_ops *ops); - -int register_ftrace_command(struct ftrace_func_command *cmd); -int unregister_ftrace_command(struct ftrace_func_command *cmd); - -enum { - FTRACE_UPDATE_CALLS = (1 << 0), - FTRACE_DISABLE_CALLS = (1 << 1), - FTRACE_UPDATE_TRACE_FUNC = (1 << 2), - FTRACE_START_FUNC_RET = (1 << 3), - FTRACE_STOP_FUNC_RET = (1 << 4), -}; +void ftrace_ops_set_global_filter(struct ftrace_ops *ops); /* * The FTRACE_UPDATE_* enum is used to pass information back @@ -355,14 +781,12 @@ enum { * IGNORE - The function is already what we want it to be * MAKE_CALL - Start tracing the function * MODIFY_CALL - Stop saving regs for the function - * MODIFY_CALL_REGS - Start saving regs for the function * MAKE_NOP - Stop tracing the function */ enum { FTRACE_UPDATE_IGNORE, FTRACE_UPDATE_MAKE_CALL, FTRACE_UPDATE_MODIFY_CALL, - FTRACE_UPDATE_MODIFY_CALL_REGS, FTRACE_UPDATE_MAKE_NOP, }; @@ -370,12 +794,18 @@ enum { FTRACE_ITER_FILTER = (1 << 0), FTRACE_ITER_NOTRACE = (1 << 1), FTRACE_ITER_PRINTALL = (1 << 2), - FTRACE_ITER_DO_HASH = (1 << 3), - FTRACE_ITER_HASH = (1 << 4), - FTRACE_ITER_ENABLED = (1 << 5), + FTRACE_ITER_DO_PROBES = (1 << 3), + FTRACE_ITER_PROBE = (1 << 4), + FTRACE_ITER_MOD = (1 << 5), + FTRACE_ITER_ENABLED = (1 << 6), + FTRACE_ITER_TOUCHED = (1 << 7), + FTRACE_ITER_ADDRS = (1 << 8), }; void arch_ftrace_update_code(int command); +void arch_ftrace_update_trampoline(struct ftrace_ops *ops); +void *arch_ftrace_trampoline_func(struct ftrace_ops *ops, struct dyn_ftrace *rec); +void arch_ftrace_trampoline_free(struct ftrace_ops *ops); struct ftrace_rec_iter; @@ -389,10 +819,13 @@ struct dyn_ftrace *ftrace_rec_iter_record(struct ftrace_rec_iter *iter); iter = ftrace_rec_iter_next(iter)) -int ftrace_update_record(struct dyn_ftrace *rec, int enable); -int ftrace_test_record(struct dyn_ftrace *rec, int enable); +int ftrace_update_record(struct dyn_ftrace *rec, bool enable); +int ftrace_test_record(struct dyn_ftrace *rec, bool enable); void ftrace_run_stop_machine(int command); unsigned long ftrace_location(unsigned long ip); +unsigned long ftrace_location_range(unsigned long start, unsigned long end); +unsigned long ftrace_get_addr_new(struct dyn_ftrace *rec); +unsigned long ftrace_get_addr_curr(struct dyn_ftrace *rec); extern ftrace_func_t ftrace_trace_function; @@ -408,8 +841,7 @@ void __init ftrace_set_early_filter(struct ftrace_ops *ops, char *buf, int enable); /* defined in arch */ -extern int ftrace_ip_converted(unsigned long ip); -extern int ftrace_dyn_arch_init(void *data); +extern int ftrace_dyn_arch_init(void); extern void ftrace_replace_code(int enable); extern int ftrace_update_ftrace_func(ftrace_func_t func); extern void ftrace_caller(void); @@ -424,6 +856,10 @@ void ftrace_modify_all_code(int command); #define FTRACE_ADDR ((unsigned long)ftrace_caller) #endif +#ifndef FTRACE_GRAPH_ADDR +#define FTRACE_GRAPH_ADDR ((unsigned long)ftrace_graph_caller) +#endif + #ifndef FTRACE_REGS_ADDR #ifdef CONFIG_DYNAMIC_FTRACE_WITH_REGS # define FTRACE_REGS_ADDR ((unsigned long)ftrace_regs_caller) @@ -432,6 +868,16 @@ void ftrace_modify_all_code(int command); #endif #endif +/* + * If an arch would like functions that are only traced + * by the function graph tracer to jump directly to its own + * trampoline, then they can define FTRACE_GRAPH_TRAMP_ADDR + * to be that address to jump to. + */ +#ifndef FTRACE_GRAPH_TRAMP_ADDR +#define FTRACE_GRAPH_TRAMP_ADDR ((unsigned long) 0) +#endif + #ifdef CONFIG_FUNCTION_GRAPH_TRACER extern void ftrace_graph_caller(void); extern int ftrace_enable_ftrace_graph_caller(void); @@ -444,7 +890,7 @@ static inline int ftrace_disable_ftrace_graph_caller(void) { return 0; } /** * ftrace_make_nop - convert code into nop * @mod: module structure if called by module load initialization - * @rec: the mcount call site record + * @rec: the call site record (e.g. mcount/fentry) * @addr: the address that the call site should be calling * * This is a very sensitive operation and great care needs @@ -466,8 +912,53 @@ extern int ftrace_make_nop(struct module *mod, struct dyn_ftrace *rec, unsigned long addr); /** + * ftrace_need_init_nop - return whether nop call sites should be initialized + * + * Normally the compiler's -mnop-mcount generates suitable nops, so we don't + * need to call ftrace_init_nop() if the code is built with that flag. + * Architectures where this is not always the case may define their own + * condition. + * + * Return must be: + * 0 if ftrace_init_nop() should be called + * Nonzero if ftrace_init_nop() should not be called + */ + +#ifndef ftrace_need_init_nop +#define ftrace_need_init_nop() (!__is_defined(CC_USING_NOP_MCOUNT)) +#endif + +/** + * ftrace_init_nop - initialize a nop call site + * @mod: module structure if called by module load initialization + * @rec: the call site record (e.g. mcount/fentry) + * + * This is a very sensitive operation and great care needs + * to be taken by the arch. The operation should carefully + * read the location, check to see if what is read is indeed + * what we expect it to be, and then on success of the compare, + * it should write to the location. + * + * The code segment at @rec->ip should contain the contents created by + * the compiler + * + * Return must be: + * 0 on success + * -EFAULT on error reading the location + * -EINVAL on a failed compare of the contents + * -EPERM on error writing to the location + * Any other value will be considered a failure. + */ +#ifndef ftrace_init_nop +static inline int ftrace_init_nop(struct module *mod, struct dyn_ftrace *rec) +{ + return ftrace_make_nop(mod, rec, MCOUNT_ADDR); +} +#endif + +/** * ftrace_make_call - convert a nop call site into a call to addr - * @rec: the mcount call site record + * @rec: the call site record (e.g. mcount/fentry) * @addr: the address that the call site should call * * This is a very sensitive operation and great care needs @@ -487,10 +978,12 @@ extern int ftrace_make_nop(struct module *mod, */ extern int ftrace_make_call(struct dyn_ftrace *rec, unsigned long addr); -#ifdef CONFIG_DYNAMIC_FTRACE_WITH_REGS +#if defined(CONFIG_DYNAMIC_FTRACE_WITH_REGS) || \ + defined(CONFIG_DYNAMIC_FTRACE_WITH_CALL_OPS) || \ + defined(CONFIG_DYNAMIC_FTRACE_WITH_DIRECT_CALLS) /** * ftrace_modify_call - convert from one addr to another (no nop) - * @rec: the mcount call site record + * @rec: the call site record (e.g. mcount/fentry) * @old_addr: the address expected to be currently called to * @addr: the address to change to * @@ -500,6 +993,9 @@ extern int ftrace_make_call(struct dyn_ftrace *rec, unsigned long addr); * what we expect it to be, and then on success of the compare, * it should write to the location. * + * When using call ops, this is called when the associated ops change, even + * when (addr == old_addr). + * * The code segment at @rec->ip should be a caller to @old_addr * * Return must be: @@ -520,28 +1016,16 @@ static inline int ftrace_modify_call(struct dyn_ftrace *rec, unsigned long old_a } #endif -/* May be defined in arch */ -extern int ftrace_arch_read_dyn_info(char *buf, int size); - extern int skip_trace(unsigned long ip); - -extern void ftrace_disable_daemon(void); -extern void ftrace_enable_daemon(void); +extern void ftrace_module_init(struct module *mod); +extern void ftrace_module_enable(struct module *mod); +extern void ftrace_release_mod(struct module *mod); #else /* CONFIG_DYNAMIC_FTRACE */ static inline int skip_trace(unsigned long ip) { return 0; } -static inline int ftrace_force_update(void) { return 0; } -static inline void ftrace_disable_daemon(void) { } -static inline void ftrace_enable_daemon(void) { } -static inline void ftrace_release_mod(struct module *mod) {} -static inline int register_ftrace_command(struct ftrace_func_command *cmd) -{ - return -EINVAL; -} -static inline int unregister_ftrace_command(char *cmd_name) -{ - return -EINVAL; -} -static inline int ftrace_text_reserved(void *start, void *end) +static inline void ftrace_module_init(struct module *mod) { } +static inline void ftrace_module_enable(struct module *mod) { } +static inline void ftrace_release_mod(struct module *mod) { } +static inline int ftrace_text_reserved(const void *start, const void *end) { return 0; } @@ -558,9 +1042,11 @@ static inline unsigned long ftrace_location(unsigned long ip) #define ftrace_regex_open(ops, flag, inod, file) ({ -ENODEV; }) #define ftrace_set_early_filter(ops, buf, enable) do { } while (0) #define ftrace_set_filter_ip(ops, ip, remove, reset) ({ -ENODEV; }) +#define ftrace_set_filter_ips(ops, ips, cnt, remove, reset) ({ -ENODEV; }) #define ftrace_set_filter(ops, buf, len, reset) ({ -ENODEV; }) #define ftrace_set_notrace(ops, buf, len, reset) ({ -ENODEV; }) #define ftrace_free_filter(ops) do { } while (0) +#define ftrace_ops_set_global_filter(ops) do { } while (0) static inline ssize_t ftrace_filter_write(struct file *file, const char __user *ubuf, size_t cnt, loff_t *ppos) { return -ENODEV; } @@ -568,9 +1054,21 @@ static inline ssize_t ftrace_notrace_write(struct file *file, const char __user size_t cnt, loff_t *ppos) { return -ENODEV; } static inline int ftrace_regex_release(struct inode *inode, struct file *file) { return -ENODEV; } + +static inline bool is_ftrace_trampoline(unsigned long addr) +{ + return false; +} #endif /* CONFIG_DYNAMIC_FTRACE */ -loff_t ftrace_filter_lseek(struct file *file, loff_t offset, int whence); +#ifdef CONFIG_FUNCTION_GRAPH_TRACER +#ifndef ftrace_graph_func +#define ftrace_graph_func ftrace_stub +#define FTRACE_OPS_GRAPH_STUB FTRACE_OPS_FL_STUB +#else +#define FTRACE_OPS_GRAPH_STUB 0 +#endif +#endif /* CONFIG_FUNCTION_GRAPH_TRACER */ /* totally disable ftrace - can not re-enable after this */ void ftrace_kill(void); @@ -605,35 +1103,41 @@ static inline void __ftrace_enabled_restore(int enabled) #endif } -#ifndef HAVE_ARCH_CALLER_ADDR +/* All archs should have this, but we define it for consistency */ +#ifndef ftrace_return_address0 +# define ftrace_return_address0 __builtin_return_address(0) +#endif + +/* Archs may use other ways for ADDR1 and beyond */ +#ifndef ftrace_return_address # ifdef CONFIG_FRAME_POINTER -# define CALLER_ADDR0 ((unsigned long)__builtin_return_address(0)) -# define CALLER_ADDR1 ((unsigned long)__builtin_return_address(1)) -# define CALLER_ADDR2 ((unsigned long)__builtin_return_address(2)) -# define CALLER_ADDR3 ((unsigned long)__builtin_return_address(3)) -# define CALLER_ADDR4 ((unsigned long)__builtin_return_address(4)) -# define CALLER_ADDR5 ((unsigned long)__builtin_return_address(5)) -# define CALLER_ADDR6 ((unsigned long)__builtin_return_address(6)) +# define ftrace_return_address(n) __builtin_return_address(n) # else -# define CALLER_ADDR0 ((unsigned long)__builtin_return_address(0)) -# define CALLER_ADDR1 0UL -# define CALLER_ADDR2 0UL -# define CALLER_ADDR3 0UL -# define CALLER_ADDR4 0UL -# define CALLER_ADDR5 0UL -# define CALLER_ADDR6 0UL +# define ftrace_return_address(n) 0UL # endif -#endif /* ifndef HAVE_ARCH_CALLER_ADDR */ - -#ifdef CONFIG_IRQSOFF_TRACER - extern void time_hardirqs_on(unsigned long a0, unsigned long a1); - extern void time_hardirqs_off(unsigned long a0, unsigned long a1); -#else - static inline void time_hardirqs_on(unsigned long a0, unsigned long a1) { } - static inline void time_hardirqs_off(unsigned long a0, unsigned long a1) { } #endif -#ifdef CONFIG_PREEMPT_TRACER +#define CALLER_ADDR0 ((unsigned long)ftrace_return_address0) +#define CALLER_ADDR1 ((unsigned long)ftrace_return_address(1)) +#define CALLER_ADDR2 ((unsigned long)ftrace_return_address(2)) +#define CALLER_ADDR3 ((unsigned long)ftrace_return_address(3)) +#define CALLER_ADDR4 ((unsigned long)ftrace_return_address(4)) +#define CALLER_ADDR5 ((unsigned long)ftrace_return_address(5)) +#define CALLER_ADDR6 ((unsigned long)ftrace_return_address(6)) + +static __always_inline unsigned long get_lock_parent_ip(void) +{ + unsigned long addr = CALLER_ADDR0; + + if (!in_lock_functions(addr)) + return addr; + addr = CALLER_ADDR1; + if (!in_lock_functions(addr)) + return addr; + return CALLER_ADDR2; +} + +#ifdef CONFIG_TRACE_PREEMPT_TOGGLE extern void trace_preempt_on(unsigned long a0, unsigned long a1); extern void trace_preempt_off(unsigned long a0, unsigned long a1); #else @@ -645,40 +1149,79 @@ static inline void __ftrace_enabled_restore(int enabled) # define trace_preempt_off(a0, a1) do { } while (0) #endif -#ifdef CONFIG_FTRACE_MCOUNT_RECORD +#ifdef CONFIG_DYNAMIC_FTRACE extern void ftrace_init(void); +#ifdef CC_USING_PATCHABLE_FUNCTION_ENTRY +#define FTRACE_CALLSITE_SECTION "__patchable_function_entries" +#else +#define FTRACE_CALLSITE_SECTION "__mcount_loc" +#endif #else static inline void ftrace_init(void) { } #endif /* * Structure that defines an entry function trace. + * It's already packed but the attribute "packed" is needed + * to remove extra padding at the end. */ struct ftrace_graph_ent { unsigned long func; /* Current function */ - int depth; -}; + unsigned long depth; +} __packed; + +/* + * Structure that defines an entry function trace with retaddr. + */ +struct fgraph_retaddr_ent { + struct ftrace_graph_ent ent; + unsigned long retaddr; /* Return address */ +} __packed; /* * Structure that defines a return function trace. + * It's already packed but the attribute "packed" is needed + * to remove extra padding at the end. */ struct ftrace_graph_ret { unsigned long func; /* Current function */ - unsigned long long calltime; - unsigned long long rettime; - /* Number of functions that overran the depth limit for current task */ - unsigned long overrun; +#ifdef CONFIG_FUNCTION_GRAPH_RETVAL + unsigned long retval; +#endif int depth; -}; + /* Number of functions that overran the depth limit for current task */ + unsigned int overrun; +} __packed; + +struct fgraph_ops; /* Type of the callback handlers for tracing function graph*/ -typedef void (*trace_func_graph_ret_t)(struct ftrace_graph_ret *); /* return */ -typedef int (*trace_func_graph_ent_t)(struct ftrace_graph_ent *); /* entry */ +typedef void (*trace_func_graph_ret_t)(struct ftrace_graph_ret *, + struct fgraph_ops *, + struct ftrace_regs *); /* return */ +typedef int (*trace_func_graph_ent_t)(struct ftrace_graph_ent *, + struct fgraph_ops *, + struct ftrace_regs *); /* entry */ + +extern int ftrace_graph_entry_stub(struct ftrace_graph_ent *trace, + struct fgraph_ops *gops, + struct ftrace_regs *fregs); +bool ftrace_pids_enabled(struct ftrace_ops *ops); #ifdef CONFIG_FUNCTION_GRAPH_TRACER -/* for init task */ -#define INIT_FTRACE_GRAPH .ret_stack = NULL, +struct fgraph_ops { + trace_func_graph_ent_t entryfunc; + trace_func_graph_ret_t retfunc; + struct ftrace_ops ops; /* for the hash lists */ + void *private; + trace_func_graph_ent_t saved_func; + int idx; +}; + +void *fgraph_reserve_data(int idx, int size_bytes); +void *fgraph_retrieve_data(int idx, int *size_bytes); +void *fgraph_retrieve_parent_data(int idx, int *size_bytes, int depth); /* * Stack of return addresses for functions @@ -688,9 +1231,10 @@ typedef int (*trace_func_graph_ent_t)(struct ftrace_graph_ent *); /* entry */ struct ftrace_ret_stack { unsigned long ret; unsigned long func; - unsigned long long calltime; - unsigned long long subtime; +#ifdef HAVE_FUNCTION_GRAPH_FP_TEST unsigned long fp; +#endif + unsigned long *retp; }; /* @@ -701,8 +1245,23 @@ struct ftrace_ret_stack { extern void return_to_handler(void); extern int -ftrace_push_return_trace(unsigned long ret, unsigned long func, int *depth, - unsigned long frame_pointer); +function_graph_enter_regs(unsigned long ret, unsigned long func, + unsigned long frame_pointer, unsigned long *retp, + struct ftrace_regs *fregs); + +static inline int function_graph_enter(unsigned long ret, unsigned long func, + unsigned long fp, unsigned long *retp) +{ + return function_graph_enter_regs(ret, func, fp, retp, NULL); +} + +struct ftrace_ret_stack * +ftrace_graph_get_ret_stack(struct task_struct *task, int skip); +unsigned long ftrace_graph_top_ret_addr(struct task_struct *task); + +unsigned long ftrace_graph_ret_addr(struct task_struct *task, int *idx, + unsigned long ret, unsigned long *retp); +unsigned long *fgraph_get_task_var(struct fgraph_ops *gops); /* * Sometimes we don't want to trace a function with the function @@ -711,20 +1270,25 @@ ftrace_push_return_trace(unsigned long ret, unsigned long func, int *depth, */ #define __notrace_funcgraph notrace -/* - * We want to which function is an entrypoint of a hardirq. - * That will help us to put a signal on output. - */ -#define __irq_entry __attribute__((__section__(".irqentry.text"))) - -/* Limits of hardirq entrypoints */ -extern char __irqentry_text_start[]; -extern char __irqentry_text_end[]; - #define FTRACE_RETFUNC_DEPTH 50 #define FTRACE_RETSTACK_ALLOC_SIZE 32 -extern int register_ftrace_graph(trace_func_graph_ret_t retfunc, - trace_func_graph_ent_t entryfunc); + +extern int register_ftrace_graph(struct fgraph_ops *ops); +extern void unregister_ftrace_graph(struct fgraph_ops *ops); + +/** + * ftrace_graph_is_dead - returns true if ftrace_graph_stop() was called + * + * ftrace_graph_stop() is called when a severe error is detected in + * the function graph tracing. This function is called by the critical + * paths of function graph to keep those paths from doing any more harm. + */ +DECLARE_STATIC_KEY_FALSE(kill_ftrace_graph); + +static inline bool ftrace_graph_is_dead(void) +{ + return static_branch_unlikely(&kill_ftrace_graph); +} extern void ftrace_graph_stop(void); @@ -732,16 +1296,12 @@ extern void ftrace_graph_stop(void); extern trace_func_graph_ret_t ftrace_graph_return; extern trace_func_graph_ent_t ftrace_graph_entry; -extern void unregister_ftrace_graph(void); - extern void ftrace_graph_init_task(struct task_struct *t); extern void ftrace_graph_exit_task(struct task_struct *t); extern void ftrace_graph_init_idle_task(struct task_struct *t, int cpu); -static inline int task_curr_ret_stack(struct task_struct *t) -{ - return t->curr_ret_stack; -} +/* Used by assembly, but to quiet sparse warnings */ +extern struct ftrace_ops *function_trace_op; static inline void pause_graph_tracing(void) { @@ -755,23 +1315,20 @@ static inline void unpause_graph_tracing(void) #else /* !CONFIG_FUNCTION_GRAPH_TRACER */ #define __notrace_funcgraph -#define __irq_entry -#define INIT_FTRACE_GRAPH static inline void ftrace_graph_init_task(struct task_struct *t) { } static inline void ftrace_graph_exit_task(struct task_struct *t) { } static inline void ftrace_graph_init_idle_task(struct task_struct *t, int cpu) { } -static inline int register_ftrace_graph(trace_func_graph_ret_t retfunc, - trace_func_graph_ent_t entryfunc) -{ - return -1; -} -static inline void unregister_ftrace_graph(void) { } +/* Define as macros as fgraph_ops may not be defined */ +#define register_ftrace_graph(ops) ({ -1; }) +#define unregister_ftrace_graph(ops) do { } while (0) -static inline int task_curr_ret_stack(struct task_struct *tsk) +static inline unsigned long +ftrace_graph_ret_addr(struct task_struct *task, int *idx, unsigned long ret, + unsigned long *retp) { - return -1; + return ret; } static inline void pause_graph_tracing(void) { } @@ -779,66 +1336,16 @@ static inline void unpause_graph_tracing(void) { } #endif /* CONFIG_FUNCTION_GRAPH_TRACER */ #ifdef CONFIG_TRACING - -/* flags for current->trace */ -enum { - TSK_TRACE_FL_TRACE_BIT = 0, - TSK_TRACE_FL_GRAPH_BIT = 1, -}; -enum { - TSK_TRACE_FL_TRACE = 1 << TSK_TRACE_FL_TRACE_BIT, - TSK_TRACE_FL_GRAPH = 1 << TSK_TRACE_FL_GRAPH_BIT, -}; - -static inline void set_tsk_trace_trace(struct task_struct *tsk) -{ - set_bit(TSK_TRACE_FL_TRACE_BIT, &tsk->trace); -} - -static inline void clear_tsk_trace_trace(struct task_struct *tsk) -{ - clear_bit(TSK_TRACE_FL_TRACE_BIT, &tsk->trace); -} - -static inline int test_tsk_trace_trace(struct task_struct *tsk) -{ - return tsk->trace & TSK_TRACE_FL_TRACE; -} - -static inline void set_tsk_trace_graph(struct task_struct *tsk) -{ - set_bit(TSK_TRACE_FL_GRAPH_BIT, &tsk->trace); -} - -static inline void clear_tsk_trace_graph(struct task_struct *tsk) -{ - clear_bit(TSK_TRACE_FL_GRAPH_BIT, &tsk->trace); -} - -static inline int test_tsk_trace_graph(struct task_struct *tsk) -{ - return tsk->trace & TSK_TRACE_FL_GRAPH; -} - enum ftrace_dump_mode; -extern enum ftrace_dump_mode ftrace_dump_on_oops; +extern int ftrace_dump_on_oops_enabled(void); extern void disable_trace_on_warning(void); -extern int __disable_trace_on_warning; - -#ifdef CONFIG_PREEMPT -#define INIT_TRACE_RECURSION .trace_recursion = 0, -#endif #else /* CONFIG_TRACING */ static inline void disable_trace_on_warning(void) { } #endif /* CONFIG_TRACING */ -#ifndef INIT_TRACE_RECURSION -#define INIT_TRACE_RECURSION -#endif - #ifdef CONFIG_FTRACE_SYSCALLS unsigned long arch_syscall_addr(int nr); |