diff options
Diffstat (limited to 'include/linux/ftrace.h')
| -rw-r--r-- | include/linux/ftrace.h | 158 |
1 files changed, 148 insertions, 10 deletions
diff --git a/include/linux/ftrace.h b/include/linux/ftrace.h index 55e6d63d46d0..a52f2f4fe030 100644 --- a/include/linux/ftrace.h +++ b/include/linux/ftrace.h @@ -10,6 +10,7 @@ #include <linux/kallsyms.h> #include <linux/linkage.h> #include <linux/bitops.h> +#include <linux/ptrace.h> #include <linux/ktime.h> #include <linux/sched.h> #include <linux/types.h> @@ -18,6 +19,28 @@ #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; @@ -29,7 +52,10 @@ 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 @@ -45,12 +71,33 @@ typedef void (*ftrace_func_t)(unsigned long ip, unsigned long parent_ip); * 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 + * (ARCH_SUPPORTS_FTRACE_SAVE_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. */ 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_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, }; struct ftrace_ops { @@ -163,7 +210,8 @@ static inline int ftrace_function_local_disabled(struct ftrace_ops *ops) return *this_cpu_ptr(ops->disabled); } -extern void ftrace_stub(unsigned long a0, unsigned long a1); +extern void ftrace_stub(unsigned long a0, unsigned long a1, + struct ftrace_ops *op, struct pt_regs *regs); #else /* !CONFIG_FUNCTION_TRACER */ /* @@ -172,6 +220,10 @@ 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) { } @@ -227,12 +279,33 @@ extern void unregister_ftrace_function_probe_all(char *glob); extern int ftrace_text_reserved(void *start, 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_ENABLED = (1 << 30), + FTRACE_FL_ENABLED = (1UL << 29), + FTRACE_FL_REGS = (1UL << 30), + FTRACE_FL_REGS_EN = (1UL << 31) }; -#define FTRACE_FL_MASK (0x3UL << 30) -#define FTRACE_REF_MAX ((1 << 30) - 1) +#define FTRACE_FL_MASK (0x7UL << 29) +#define FTRACE_REF_MAX ((1UL << 29) - 1) struct dyn_ftrace { union { @@ -244,6 +317,8 @@ struct dyn_ftrace { }; 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(struct ftrace_ops *ops, unsigned char *buf, int len, int reset); int ftrace_set_notrace(struct ftrace_ops *ops, unsigned char *buf, @@ -263,9 +338,23 @@ enum { 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 + * 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, }; @@ -317,7 +406,9 @@ extern int ftrace_dyn_arch_init(void *data); 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); @@ -325,6 +416,15 @@ void ftrace_modify_all_code(int command); #ifndef FTRACE_ADDR #define FTRACE_ADDR ((unsigned long)ftrace_caller) #endif + +#ifndef FTRACE_REGS_ADDR +#ifdef ARCH_SUPPORTS_FTRACE_SAVE_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); @@ -380,6 +480,39 @@ extern int ftrace_make_nop(struct module *mod, */ extern int ftrace_make_call(struct dyn_ftrace *rec, unsigned long addr); +#ifdef ARCH_SUPPORTS_FTRACE_SAVE_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); @@ -387,7 +520,7 @@ extern int skip_trace(unsigned long ip); 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_disable_daemon(void) { } @@ -405,6 +538,10 @@ static inline int ftrace_text_reserved(void *start, 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 @@ -413,6 +550,7 @@ static inline int ftrace_text_reserved(void *start, void *end) */ #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) |