diff options
Diffstat (limited to 'include/linux/ftrace.h')
| -rw-r--r-- | include/linux/ftrace.h | 152 |
1 files changed, 129 insertions, 23 deletions
diff --git a/include/linux/ftrace.h b/include/linux/ftrace.h index 8a8cb3c401b2..7247d35c3d16 100644 --- a/include/linux/ftrace.h +++ b/include/linux/ftrace.h @@ -51,6 +51,7 @@ static inline void early_trace_init(void) { } struct module; struct ftrace_hash; +struct ftrace_direct_func; #if defined(CONFIG_FUNCTION_TRACER) && defined(CONFIG_MODULES) && \ defined(CONFIG_DYNAMIC_FTRACE) @@ -142,24 +143,30 @@ ftrace_func_t ftrace_ops_get_func(struct ftrace_ops *ops); * 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) */ enum { - FTRACE_OPS_FL_ENABLED = 1 << 0, - FTRACE_OPS_FL_DYNAMIC = 1 << 1, - FTRACE_OPS_FL_SAVE_REGS = 1 << 2, - FTRACE_OPS_FL_SAVE_REGS_IF_SUPPORTED = 1 << 3, - FTRACE_OPS_FL_RECURSION_SAFE = 1 << 4, - FTRACE_OPS_FL_STUB = 1 << 5, - FTRACE_OPS_FL_INITIALIZED = 1 << 6, - FTRACE_OPS_FL_DELETED = 1 << 7, - FTRACE_OPS_FL_ADDING = 1 << 8, - FTRACE_OPS_FL_REMOVING = 1 << 9, - FTRACE_OPS_FL_MODIFYING = 1 << 10, - FTRACE_OPS_FL_ALLOC_TRAMP = 1 << 11, - FTRACE_OPS_FL_IPMODIFY = 1 << 12, - FTRACE_OPS_FL_PID = 1 << 13, - FTRACE_OPS_FL_RCU = 1 << 14, - FTRACE_OPS_FL_TRACE_ARRAY = 1 << 15, + 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_SAFE = 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), }; #ifdef CONFIG_DYNAMIC_FTRACE @@ -239,6 +246,70 @@ static inline void ftrace_free_init_mem(void) { } static inline void ftrace_free_mem(struct module *mod, void *start, void *end) { } #endif /* CONFIG_FUNCTION_TRACER */ +struct ftrace_func_entry { + struct hlist_node hlist; + unsigned long ip; + unsigned long direct; /* for direct lookup only */ +}; + +struct dyn_ftrace; + +#ifdef CONFIG_DYNAMIC_FTRACE_WITH_DIRECT_CALLS +extern int ftrace_direct_func_count; +int register_ftrace_direct(unsigned long ip, unsigned long addr); +int unregister_ftrace_direct(unsigned long ip, unsigned long addr); +int modify_ftrace_direct(unsigned long ip, unsigned long old_addr, unsigned long new_addr); +struct ftrace_direct_func *ftrace_find_direct_func(unsigned long addr); +int ftrace_modify_direct_caller(struct ftrace_func_entry *entry, + struct dyn_ftrace *rec, + unsigned long old_addr, + unsigned long new_addr); +#else +# define ftrace_direct_func_count 0 +static inline int register_ftrace_direct(unsigned long ip, unsigned long addr) +{ + return -ENOTSUPP; +} +static inline int unregister_ftrace_direct(unsigned long ip, unsigned long addr) +{ + return -ENOTSUPP; +} +static inline int modify_ftrace_direct(unsigned long ip, + unsigned long old_addr, unsigned long new_addr) +{ + return -ENOTSUPP; +} +static inline struct ftrace_direct_func *ftrace_find_direct_func(unsigned long addr) +{ + return NULL; +} +static inline int ftrace_modify_direct_caller(struct ftrace_func_entry *entry, + struct dyn_ftrace *rec, + unsigned long old_addr, + unsigned long new_addr) +{ + return -ENODEV; +} +#endif /* CONFIG_DYNAMIC_FTRACE_WITH_DIRECT_CALLS */ + +#ifndef CONFIG_HAVE_DYNAMIC_FTRACE_WITH_DIRECT_CALLS +/* + * 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. + * + * 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 arch_ftrace_set_direct_caller(struct pt_regs *regs, + unsigned long addr) { } +#endif /* CONFIG_HAVE_DYNAMIC_FTRACE_WITH_DIRECT_CALLS */ + #ifdef CONFIG_STACK_TRACER extern int stack_tracer_enabled; @@ -291,8 +362,6 @@ static inline void stack_tracer_enable(void) { } int ftrace_arch_code_modify_prepare(void); int ftrace_arch_code_modify_post_process(void); -struct dyn_ftrace; - enum ftrace_bug_type { FTRACE_BUG_UNKNOWN, FTRACE_BUG_INIT, @@ -330,6 +399,7 @@ bool is_ftrace_trampoline(unsigned long addr); * 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 * * 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 @@ -345,10 +415,12 @@ enum { 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), }; -#define FTRACE_REF_MAX_SHIFT 25 -#define FTRACE_FL_BITS 7 +#define FTRACE_REF_MAX_SHIFT 23 +#define FTRACE_FL_BITS 9 #define FTRACE_FL_MASKED_BITS ((1UL << FTRACE_FL_BITS) - 1) #define FTRACE_FL_MASK (FTRACE_FL_MASKED_BITS << FTRACE_REF_MAX_SHIFT) #define FTRACE_REF_MAX ((1UL << FTRACE_REF_MAX_SHIFT) - 1) @@ -499,7 +571,7 @@ 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 @@ -520,9 +592,38 @@ static inline int ftrace_disable_ftrace_graph_caller(void) { return 0; } extern int ftrace_make_nop(struct module *mod, struct dyn_ftrace *rec, unsigned long addr); + +/** + * 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 @@ -545,7 +646,7 @@ 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 + * @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 * @@ -709,6 +810,11 @@ static inline unsigned long get_lock_parent_ip(void) #ifdef CONFIG_FTRACE_MCOUNT_RECORD 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 |