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Diffstat (limited to 'include/linux/ftrace.h')
| -rw-r--r-- | include/linux/ftrace.h | 687 |
1 files changed, 687 insertions, 0 deletions
diff --git a/include/linux/ftrace.h b/include/linux/ftrace.h new file mode 100644 index 00000000..72a6cabb --- /dev/null +++ b/include/linux/ftrace.h @@ -0,0 +1,687 @@ +/* + * Ftrace header. For implementation details beyond the random comments + * scattered below, see: Documentation/trace/ftrace-design.txt + */ + +#ifndef _LINUX_FTRACE_H +#define _LINUX_FTRACE_H + +#include <linux/trace_clock.h> +#include <linux/kallsyms.h> +#include <linux/linkage.h> +#include <linux/bitops.h> +#include <linux/ktime.h> +#include <linux/sched.h> +#include <linux/types.h> +#include <linux/init.h> +#include <linux/fs.h> + +#include <asm/ftrace.h> + +struct module; +struct ftrace_hash; + +#ifdef CONFIG_FUNCTION_TRACER + +extern int ftrace_enabled; +extern int +ftrace_enable_sysctl(struct ctl_table *table, int write, + void __user *buffer, size_t *lenp, + loff_t *ppos); + +typedef void (*ftrace_func_t)(unsigned long ip, unsigned long parent_ip); + +/* + * FTRACE_OPS_FL_* bits denote the state of ftrace_ops struct and are + * set in the flags member. + * + * 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 + */ +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, +}; + +struct ftrace_ops { + ftrace_func_t func; + struct ftrace_ops *next; + unsigned long flags; + int __percpu *disabled; +#ifdef CONFIG_DYNAMIC_FTRACE + struct ftrace_hash *notrace_hash; + struct ftrace_hash *filter_hash; +#endif +}; + +extern int function_trace_stop; + +/* + * Type of the current tracing. + */ +enum ftrace_tracing_type_t { + FTRACE_TYPE_ENTER = 0, /* Hook the call of the function */ + FTRACE_TYPE_RETURN, /* Hook the return of the function */ +}; + +/* 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 + * so use them sparely. Never free an ftrace_op or modify the + * next pointer after it has been registered. Even after unregistering + * it, the next pointer may still be used internally. + */ +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. + */ +static inline void ftrace_function_local_enable(struct ftrace_ops *ops) +{ + if (WARN_ON_ONCE(!(ops->flags & FTRACE_OPS_FL_CONTROL))) + return; + + (*this_cpu_ptr(ops->disabled))--; +} + +/** + * ftrace_function_local_disable - 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. + */ +static inline void ftrace_function_local_disable(struct ftrace_ops *ops) +{ + if (WARN_ON_ONCE(!(ops->flags & FTRACE_OPS_FL_CONTROL))) + return; + + (*this_cpu_ptr(ops->disabled))++; +} + +/** + * ftrace_function_local_disabled - returns ftrace_ops disabled value + * on current cpu + * + * 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. + */ +static inline int ftrace_function_local_disabled(struct ftrace_ops *ops) +{ + WARN_ON_ONCE(!(ops->flags & FTRACE_OPS_FL_CONTROL)); + return *this_cpu_ptr(ops->disabled); +} + +extern void ftrace_stub(unsigned long a0, unsigned long a1); + +#else /* !CONFIG_FUNCTION_TRACER */ +/* + * (un)register_ftrace_function must be a macro since the ops parameter + * must not be evaluated. + */ +#define register_ftrace_function(ops) ({ 0; }) +#define unregister_ftrace_function(ops) ({ 0; }) +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); +#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); +}; + +#ifdef CONFIG_DYNAMIC_FTRACE + +int ftrace_arch_code_modify_prepare(void); +int ftrace_arch_code_modify_post_process(void); + +void ftrace_bug(int err, unsigned long ip); + +struct seq_file; + +struct ftrace_probe_ops { + void (*func)(unsigned long ip, + unsigned long parent_ip, + void **data); + int (*callback)(unsigned long ip, void **data); + void (*free)(void **data); + int (*print)(struct seq_file *m, + unsigned long ip, + struct ftrace_probe_ops *ops, + void *data); +}; + +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); + +extern int ftrace_text_reserved(void *start, void *end); + +enum { + FTRACE_FL_ENABLED = (1 << 30), +}; + +#define FTRACE_FL_MASK (0x3UL << 30) +#define FTRACE_REF_MAX ((1 << 30) - 1) + +struct dyn_ftrace { + union { + unsigned long ip; /* address of mcount call-site */ + struct dyn_ftrace *freelist; + }; + unsigned long flags; + struct dyn_arch_ftrace arch; +}; + +int ftrace_force_update(void); +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, + int len, int reset); +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), +}; + +enum { + FTRACE_UPDATE_IGNORE, + FTRACE_UPDATE_MAKE_CALL, + FTRACE_UPDATE_MAKE_NOP, +}; + +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), +}; + +void arch_ftrace_update_code(int command); + +struct ftrace_rec_iter; + +struct ftrace_rec_iter *ftrace_rec_iter_start(void); +struct ftrace_rec_iter *ftrace_rec_iter_next(struct ftrace_rec_iter *iter); +struct dyn_ftrace *ftrace_rec_iter_record(struct ftrace_rec_iter *iter); + +int ftrace_update_record(struct dyn_ftrace *rec, int enable); +int ftrace_test_record(struct dyn_ftrace *rec, int enable); +void ftrace_run_stop_machine(int command); +int ftrace_location(unsigned long ip); + +extern ftrace_func_t ftrace_trace_function; + +int ftrace_regex_open(struct ftrace_ops *ops, int flag, + struct inode *inode, struct file *file); +ssize_t ftrace_filter_write(struct file *file, const char __user *ubuf, + size_t cnt, loff_t *ppos); +ssize_t ftrace_notrace_write(struct file *file, const char __user *ubuf, + size_t cnt, loff_t *ppos); +loff_t ftrace_regex_lseek(struct file *file, loff_t offset, int origin); +int ftrace_regex_release(struct inode *inode, struct file *file); + +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_update_ftrace_func(ftrace_func_t func); +extern void ftrace_caller(void); +extern void ftrace_call(void); +extern void mcount_call(void); + +#ifndef FTRACE_ADDR +#define FTRACE_ADDR ((unsigned long)ftrace_caller) +#endif +#ifdef CONFIG_FUNCTION_GRAPH_TRACER +extern void ftrace_graph_caller(void); +extern int ftrace_enable_ftrace_graph_caller(void); +extern int ftrace_disable_ftrace_graph_caller(void); +#else +static inline int ftrace_enable_ftrace_graph_caller(void) { return 0; } +static inline int ftrace_disable_ftrace_graph_caller(void) { return 0; } +#endif + +/** + * ftrace_make_nop - convert code into nop + * @mod: module structure if called by module load initialization + * @rec: the mcount call site record + * @addr: the address that the call site should be calling + * + * 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 be a caller to @addr + * + * 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. + */ +extern int ftrace_make_nop(struct module *mod, + struct dyn_ftrace *rec, unsigned long addr); + +/** + * ftrace_make_call - convert a nop call site into a call to addr + * @rec: the mcount call site record + * @addr: the address that the call site should call + * + * 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 be a nop + * + * 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. + */ +extern int ftrace_make_call(struct dyn_ftrace *rec, unsigned long addr); + +/* 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); +#else +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) +{ + return 0; +} + +/* + * Again users of functions that have ftrace_ops may not + * have them defined when ftrace is not enabled, but these + * functions may still be called. Use a macro instead of inline. + */ +#define ftrace_regex_open(ops, flag, inod, file) ({ -ENODEV; }) +#define ftrace_set_early_filter(ops, buf, enable) do { } while (0) +#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) + +static inline ssize_t ftrace_filter_write(struct file *file, const char __user *ubuf, + size_t cnt, loff_t *ppos) { return -ENODEV; } +static inline ssize_t ftrace_notrace_write(struct file *file, const char __user *ubuf, + size_t cnt, loff_t *ppos) { return -ENODEV; } +static inline loff_t ftrace_regex_lseek(struct file *file, loff_t offset, int origin) +{ + return -ENODEV; +} +static inline int +ftrace_regex_release(struct inode *inode, struct file *file) { return -ENODEV; } +#endif /* CONFIG_DYNAMIC_FTRACE */ + +/* totally disable ftrace - can not re-enable after this */ +void ftrace_kill(void); + +static inline void tracer_disable(void) +{ +#ifdef CONFIG_FUNCTION_TRACER + ftrace_enabled = 0; +#endif +} + +/* + * Ftrace disable/restore without lock. Some synchronization mechanism + * must be used to prevent ftrace_enabled to be changed between + * disable/restore. + */ +static inline int __ftrace_enabled_save(void) +{ +#ifdef CONFIG_FUNCTION_TRACER + int saved_ftrace_enabled = ftrace_enabled; + ftrace_enabled = 0; + return saved_ftrace_enabled; +#else + return 0; +#endif +} + +static inline void __ftrace_enabled_restore(int enabled) +{ +#ifdef CONFIG_FUNCTION_TRACER + ftrace_enabled = enabled; +#endif +} + +#ifndef HAVE_ARCH_CALLER_ADDR +# 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)) +# 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 +# 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 + extern void trace_preempt_on(unsigned long a0, unsigned long a1); + extern void trace_preempt_off(unsigned long a0, unsigned long a1); +#else + static inline void trace_preempt_on(unsigned long a0, unsigned long a1) { } + static inline void trace_preempt_off(unsigned long a0, unsigned long a1) { } +#endif + +#ifdef CONFIG_FTRACE_MCOUNT_RECORD +extern void ftrace_init(void); +#else +static inline void ftrace_init(void) { } +#endif + +/* + * Structure that defines an entry function trace. + */ +struct ftrace_graph_ent { + unsigned long func; /* Current function */ + int depth; +}; + +/* + * Structure that defines a return function trace. + */ +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; + int depth; +}; + +/* 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 */ + +#ifdef CONFIG_FUNCTION_GRAPH_TRACER + +/* for init task */ +#define INIT_FTRACE_GRAPH .ret_stack = NULL, + +/* + * Stack of return addresses for functions + * of a thread. + * Used in struct thread_info + */ +struct ftrace_ret_stack { + unsigned long ret; + unsigned long func; + unsigned long long calltime; + unsigned long long subtime; + unsigned long fp; +}; + +/* + * Primary handler of a function return. + * It relays on ftrace_return_to_handler. + * Defined in entry_32/64.S + */ +extern void return_to_handler(void); + +extern int +ftrace_push_return_trace(unsigned long ret, unsigned long func, int *depth, + unsigned long frame_pointer); + +/* + * Sometimes we don't want to trace a function with the function + * graph tracer but we want them to keep traced by the usual function + * tracer if the function graph tracer is not configured. + */ +#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 void ftrace_graph_stop(void); + +/* The current handlers in use */ +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; +} + +static inline void pause_graph_tracing(void) +{ + atomic_inc(¤t->tracing_graph_pause); +} + +static inline void unpause_graph_tracing(void) +{ + atomic_dec(¤t->tracing_graph_pause); +} +#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) { } + +static inline int task_curr_ret_stack(struct task_struct *tsk) +{ + return -1; +} + +static inline void pause_graph_tracing(void) { } +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; + +#ifdef CONFIG_PREEMPT +#define INIT_TRACE_RECURSION .trace_recursion = 0, +#endif + +#endif /* CONFIG_TRACING */ + +#ifndef INIT_TRACE_RECURSION +#define INIT_TRACE_RECURSION +#endif + +#ifdef CONFIG_FTRACE_SYSCALLS + +unsigned long arch_syscall_addr(int nr); + +#endif /* CONFIG_FTRACE_SYSCALLS */ + +#endif /* _LINUX_FTRACE_H */ |