diff options
Diffstat (limited to 'include/linux/ftrace.h')
| -rw-r--r-- | include/linux/ftrace.h | 427 |
1 files changed, 376 insertions, 51 deletions
diff --git a/include/linux/ftrace.h b/include/linux/ftrace.h index dcd6a7c3a43..404a686a364 100644 --- a/include/linux/ftrace.h +++ b/include/linux/ftrace.h @@ -10,7 +10,7 @@ #include <linux/kallsyms.h> #include <linux/linkage.h> #include <linux/bitops.h> -#include <linux/module.h> +#include <linux/ptrace.h> #include <linux/ktime.h> #include <linux/sched.h> #include <linux/types.h> @@ -19,6 +19,31 @@ #include <asm/ftrace.h> +/* + * If the arch supports passing the variable contents of + * function_trace_op as the third parameter back from the + * mcount call, then the arch should define this as 1. + */ +#ifndef ARCH_SUPPORTS_FTRACE_OPS +#define ARCH_SUPPORTS_FTRACE_OPS 0 +#endif + +/* + * 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. + */ +#if !defined(CONFIG_HAVE_FUNCTION_TRACE_MCOUNT_TEST) || \ + !ARCH_SUPPORTS_FTRACE_OPS +# define FTRACE_FORCE_LIST_FUNC 1 +#else +# define FTRACE_FORCE_LIST_FUNC 0 +#endif + + +struct module; +struct ftrace_hash; + #ifdef CONFIG_FUNCTION_TRACER extern int ftrace_enabled; @@ -27,11 +52,79 @@ 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); +struct ftrace_ops; + +typedef void (*ftrace_func_t)(unsigned long ip, unsigned long parent_ip, + struct ftrace_ops *op, struct pt_regs *regs); + +/* + * 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 + * 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 + * (CONFIG_DYNAMIC_FTRACE_WITH_REGS is not defined), then the + * ftrace_ops will fail to register, unless the next flag + * is set. + * SAVE_REGS_IF_SUPPORTED - This is the same as SAVE_REGS, but if the + * handler can handle an arch that does not save regs + * (the handler tests if regs == NULL), then it can set + * this flag instead. It will not fail registering the ftrace_ops + * but, the regs field will be NULL if the arch does not support + * 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. + * 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. + */ +enum { + FTRACE_OPS_FL_ENABLED = 1 << 0, + FTRACE_OPS_FL_DYNAMIC = 1 << 1, + FTRACE_OPS_FL_CONTROL = 1 << 2, + FTRACE_OPS_FL_SAVE_REGS = 1 << 3, + FTRACE_OPS_FL_SAVE_REGS_IF_SUPPORTED = 1 << 4, + FTRACE_OPS_FL_RECURSION_SAFE = 1 << 5, + FTRACE_OPS_FL_STUB = 1 << 6, + FTRACE_OPS_FL_INITIALIZED = 1 << 7, + FTRACE_OPS_FL_DELETED = 1 << 8, +}; +/* + * Note, ftrace_ops can be referenced outside of RCU protection. + * (Although, for perf, the control ops prevent that). 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; + ftrace_func_t func; + struct ftrace_ops *next; + unsigned long flags; + int __percpu *disabled; + void *private; +#ifdef CONFIG_DYNAMIC_FTRACE + struct ftrace_hash *notrace_hash; + struct ftrace_hash *filter_hash; + struct mutex regex_lock; +#endif }; extern int function_trace_stop; @@ -84,7 +177,57 @@ int register_ftrace_function(struct ftrace_ops *ops); int unregister_ftrace_function(struct ftrace_ops *ops); void clear_ftrace_function(void); -extern void ftrace_stub(unsigned long a0, unsigned long a1); +/** + * 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, + struct ftrace_ops *op, struct pt_regs *regs); #else /* !CONFIG_FUNCTION_TRACER */ /* @@ -93,6 +236,10 @@ extern void ftrace_stub(unsigned long a0, unsigned long a1); */ #define register_ftrace_function(ops) ({ 0; }) #define unregister_ftrace_function(ops) ({ 0; }) +static inline int ftrace_nr_registered_ops(void) +{ + return 0; +} static inline void clear_ftrace_function(void) { } static inline void ftrace_kill(void) { } static inline void ftrace_stop(void) { } @@ -110,7 +257,8 @@ stack_trace_sysctl(struct ctl_table *table, int write, struct ftrace_func_command { struct list_head list; char *name; - int (*func)(char *func, char *cmd, + int (*func)(struct ftrace_hash *hash, + char *func, char *cmd, char *params, int enable); }; @@ -119,14 +267,18 @@ struct ftrace_func_command { 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 (*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, @@ -143,46 +295,150 @@ 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); +extern int ftrace_text_reserved(const void *start, const void *end); +extern int ftrace_nr_registered_ops(void); + +/* + * The dyn_ftrace record's flags field is split into two parts. + * the first part which is '0-FTRACE_REF_MAX' is a counter of + * the number of callbacks that have registered the function that + * the dyn_ftrace descriptor represents. + * + * The second part is a mask: + * 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. + * + * 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 + * 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_FREE = (1 << 0), - FTRACE_FL_FAILED = (1 << 1), - FTRACE_FL_FILTER = (1 << 2), - FTRACE_FL_ENABLED = (1 << 3), - FTRACE_FL_NOTRACE = (1 << 4), - FTRACE_FL_CONVERTED = (1 << 5), + FTRACE_FL_ENABLED = (1UL << 29), + FTRACE_FL_REGS = (1UL << 30), + FTRACE_FL_REGS_EN = (1UL << 31) }; +#define FTRACE_FL_MASK (0x7UL << 29) +#define FTRACE_REF_MAX ((1UL << 29) - 1) + struct dyn_ftrace { - union { - unsigned long ip; /* address of mcount call-site */ - struct dyn_ftrace *freelist; - }; - union { - unsigned long flags; - struct dyn_ftrace *newlist; - }; - struct dyn_arch_ftrace arch; + unsigned long ip; /* address of mcount call-site */ + unsigned long flags; + struct dyn_arch_ftrace arch; }; int ftrace_force_update(void); -void ftrace_set_filter(unsigned char *buf, int len, int reset); +int ftrace_set_filter_ip(struct ftrace_ops *ops, unsigned long ip, + 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, + 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), +}; + +/* + * The FTRACE_UPDATE_* enum is used to pass information back + * from the ftrace_update_record() and ftrace_test_record() + * functions. These are called by the code update routines + * to find out what is to be done for a given function. + * + * 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 + * MAKE_NOP - Stop tracing the function + */ +enum { + FTRACE_UPDATE_IGNORE, + FTRACE_UPDATE_MAKE_CALL, + FTRACE_UPDATE_MODIFY_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); + +#define for_ftrace_rec_iter(iter) \ + for (iter = ftrace_rec_iter_start(); \ + 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); +void ftrace_run_stop_machine(int command); +unsigned long ftrace_location(unsigned long ip); +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; + +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); +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_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); +extern void ftrace_regs_caller(void); extern void ftrace_call(void); +extern void ftrace_regs_call(void); extern void mcount_call(void); +void ftrace_modify_all_code(int command); + #ifndef FTRACE_ADDR #define FTRACE_ADDR ((unsigned long)ftrace_caller) #endif + +#ifndef FTRACE_REGS_ADDR +#ifdef CONFIG_DYNAMIC_FTRACE_WITH_REGS +# define FTRACE_REGS_ADDR ((unsigned long)ftrace_regs_caller) +#else +# define FTRACE_REGS_ADDR FTRACE_ADDR +#endif +#endif + #ifdef CONFIG_FUNCTION_GRAPH_TRACER extern void ftrace_graph_caller(void); extern int ftrace_enable_ftrace_graph_caller(void); @@ -238,34 +494,89 @@ 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 +/** + * ftrace_modify_call - convert from one addr to another (no nop) + * @rec: the mcount call site record + * @old_addr: the address expected to be currently called to + * @addr: the address to change to + * + * 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 @old_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_modify_call(struct dyn_ftrace *rec, unsigned long old_addr, + unsigned long addr); +#else +/* Should never be called */ +static inline int ftrace_modify_call(struct dyn_ftrace *rec, unsigned long old_addr, + unsigned long addr) +{ + return -EINVAL; +} +#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_module_init(struct module *mod); extern void ftrace_disable_daemon(void); extern void ftrace_enable_daemon(void); -#else +#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_set_filter(unsigned char *buf, int len, int reset) -{ -} 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) +static inline void ftrace_module_init(struct module *mod) {} +static inline __init int register_ftrace_command(struct ftrace_func_command *cmd) { return -EINVAL; } -static inline int unregister_ftrace_command(char *cmd_name) +static inline __init int unregister_ftrace_command(char *cmd_name) { return -EINVAL; } -static inline int ftrace_text_reserved(void *start, void *end) +static inline int ftrace_text_reserved(const void *start, const void *end) +{ + return 0; +} +static inline unsigned long ftrace_location(unsigned long ip) { 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_ip(ops, ip, 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) + +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 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 */ @@ -301,25 +612,27 @@ 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 */ +#endif + +#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)) #ifdef CONFIG_IRQSOFF_TRACER extern void time_hardirqs_on(unsigned long a0, unsigned long a1); @@ -333,8 +646,12 @@ static inline void __ftrace_enabled_restore(int enabled) 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) { } +/* + * Use defines instead of static inlines because some arches will make code out + * of the CALLER_ADDR, when we really want these to be a real nop. + */ +# define trace_preempt_on(a0, a1) do { } while (0) +# define trace_preempt_off(a0, a1) do { } while (0) #endif #ifdef CONFIG_FTRACE_MCOUNT_RECORD @@ -413,6 +730,7 @@ ftrace_push_return_trace(unsigned long ret, unsigned long func, int *depth, extern char __irqentry_text_start[]; extern char __irqentry_text_end[]; +#define FTRACE_NOTRACE_DEPTH 65536 #define FTRACE_RETFUNC_DEPTH 50 #define FTRACE_RETSTACK_ALLOC_SIZE 32 extern int register_ftrace_graph(trace_func_graph_ret_t retfunc, @@ -428,6 +746,7 @@ 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) { @@ -451,6 +770,7 @@ static inline void unpause_graph_tracing(void) 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) @@ -514,10 +834,15 @@ enum ftrace_dump_mode; extern enum ftrace_dump_mode ftrace_dump_on_oops; +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 |