diff options
| -rw-r--r-- | include/linux/ftrace.h | 16 | ||||
| -rw-r--r-- | kernel/trace/ftrace.c | 106 |
2 files changed, 111 insertions, 11 deletions
diff --git a/include/linux/ftrace.h b/include/linux/ftrace.h index 106b7909d50..f0a0ecc63b5 100644 --- a/include/linux/ftrace.h +++ b/include/linux/ftrace.h @@ -95,6 +95,13 @@ stack_trace_sysctl(struct ctl_table *table, int write, loff_t *ppos); #endif +struct ftrace_func_command { + struct list_head list; + char *name; + int (*func)(char *func, char *cmd, + char *params, int enable); +}; + #ifdef CONFIG_DYNAMIC_FTRACE /* asm/ftrace.h must be defined for archs supporting dynamic ftrace */ #include <asm/ftrace.h> @@ -119,6 +126,9 @@ struct dyn_ftrace { int ftrace_force_update(void); void ftrace_set_filter(unsigned char *buf, int len, int reset); +int register_ftrace_command(struct ftrace_func_command *cmd); +int unregister_ftrace_command(struct ftrace_func_command *cmd); + /* defined in arch */ extern int ftrace_ip_converted(unsigned long ip); extern int ftrace_dyn_arch_init(void *data); @@ -202,6 +212,12 @@ extern void ftrace_enable_daemon(void); # define ftrace_disable_daemon() do { } while (0) # define ftrace_enable_daemon() do { } while (0) static inline void ftrace_release(void *start, unsigned long size) { } +static inline int register_ftrace_command(struct ftrace_func_command *cmd) +{ +} +static inline int unregister_ftrace_command(char *cmd_name) +{ +} #endif /* CONFIG_DYNAMIC_FTRACE */ /* totally disable ftrace - can not re-enable after this */ diff --git a/kernel/trace/ftrace.c b/kernel/trace/ftrace.c index 340f88b68d9..45a44c40256 100644 --- a/kernel/trace/ftrace.c +++ b/kernel/trace/ftrace.c @@ -1239,9 +1239,93 @@ static void ftrace_match_module_records(char *buff, char *mod, int enable) spin_unlock(&ftrace_lock); } +/* + * We register the module command as a template to show others how + * to register the a command as well. + */ + +static int +ftrace_mod_callback(char *func, char *cmd, char *param, int enable) +{ + char *mod; + + /* + * cmd == 'mod' because we only registered this func + * for the 'mod' ftrace_func_command. + * But if you register one func with multiple commands, + * you can tell which command was used by the cmd + * parameter. + */ + + /* we must have a module name */ + if (!param) + return -EINVAL; + + mod = strsep(¶m, ":"); + if (!strlen(mod)) + return -EINVAL; + + ftrace_match_module_records(func, mod, enable); + return 0; +} + +static struct ftrace_func_command ftrace_mod_cmd = { + .name = "mod", + .func = ftrace_mod_callback, +}; + +static int __init ftrace_mod_cmd_init(void) +{ + return register_ftrace_command(&ftrace_mod_cmd); +} +device_initcall(ftrace_mod_cmd_init); + +static LIST_HEAD(ftrace_commands); +static DEFINE_MUTEX(ftrace_cmd_mutex); + +int register_ftrace_command(struct ftrace_func_command *cmd) +{ + struct ftrace_func_command *p; + int ret = 0; + + mutex_lock(&ftrace_cmd_mutex); + list_for_each_entry(p, &ftrace_commands, list) { + if (strcmp(cmd->name, p->name) == 0) { + ret = -EBUSY; + goto out_unlock; + } + } + list_add(&cmd->list, &ftrace_commands); + out_unlock: + mutex_unlock(&ftrace_cmd_mutex); + + return ret; +} + +int unregister_ftrace_command(struct ftrace_func_command *cmd) +{ + struct ftrace_func_command *p, *n; + int ret = -ENODEV; + + mutex_lock(&ftrace_cmd_mutex); + list_for_each_entry_safe(p, n, &ftrace_commands, list) { + if (strcmp(cmd->name, p->name) == 0) { + ret = 0; + list_del_init(&p->list); + goto out_unlock; + } + } + out_unlock: + mutex_unlock(&ftrace_cmd_mutex); + + return ret; +} + static int ftrace_process_regex(char *buff, int len, int enable) { - char *func, *mod, *command, *next = buff; + struct ftrace_func_command *p; + char *func, *command, *next = buff; + int ret = -EINVAL; func = strsep(&next, ":"); @@ -1250,21 +1334,21 @@ static int ftrace_process_regex(char *buff, int len, int enable) return 0; } - /* command fonud */ + /* command found */ command = strsep(&next, ":"); - if (strcmp(command, "mod") == 0) { - /* only match modules */ - if (!next) - return -EINVAL; - - mod = strsep(&next, ":"); - ftrace_match_module_records(func, mod, enable); - return 0; + mutex_lock(&ftrace_cmd_mutex); + list_for_each_entry(p, &ftrace_commands, list) { + if (strcmp(p->name, command) == 0) { + ret = p->func(func, command, next, enable); + goto out_unlock; + } } + out_unlock: + mutex_unlock(&ftrace_cmd_mutex); - return -EINVAL; + return ret; } static ssize_t |