Add dynamic ftrace_event_call support to ftrace. Trace engines can adds new ftrace_event_call to ftrace on the fly. Each operator functions of the call takes a ftrace_event_call data structure as an argument, because these functions may be shared among several ftrace_event_calls.
Changes from v13: - Define remove_subsystem_dir() always (revirt a2ca5e03), because trace_remove_event_call() uses it. - Modify syscall tracer because of ftrace_event_call change. Signed-off-by: Masami Hiramatsu <[email protected]> Acked-by: Frederic Weisbecker <[email protected]> Cc: Ananth N Mavinakayanahalli <[email protected]> Cc: Avi Kivity <[email protected]> Cc: Andi Kleen <[email protected]> Cc: Christoph Hellwig <[email protected]> Cc: Frank Ch. Eigler <[email protected]> Cc: H. Peter Anvin <[email protected]> Cc: Ingo Molnar <[email protected]> Cc: Jason Baron <[email protected]> Cc: Jim Keniston <[email protected]> Cc: K.Prasad <[email protected]> Cc: Lai Jiangshan <[email protected]> Cc: Li Zefan <[email protected]> Cc: Przemysław Pawełczyk <[email protected]> Cc: Roland McGrath <[email protected]> Cc: Sam Ravnborg <[email protected]> Cc: Srikar Dronamraju <[email protected]> Cc: Steven Rostedt <[email protected]> Cc: Tom Zanussi <[email protected]> Cc: Vegard Nossum <[email protected]> --- include/linux/ftrace_event.h | 14 +++-- include/linux/syscalls.h | 4 + include/trace/ftrace.h | 19 +++---- include/trace/syscall.h | 8 +-- kernel/trace/trace_events.c | 119 +++++++++++++++++++++++++++++------------ kernel/trace/trace_export.c | 23 ++++---- kernel/trace/trace_syscalls.c | 16 +++--- 7 files changed, 125 insertions(+), 78 deletions(-) diff --git a/include/linux/ftrace_event.h b/include/linux/ftrace_event.h index 189806b..9af68ce 100644 --- a/include/linux/ftrace_event.h +++ b/include/linux/ftrace_event.h @@ -112,13 +112,13 @@ struct ftrace_event_call { struct dentry *dir; struct trace_event *event; int enabled; - int (*regfunc)(void *); - void (*unregfunc)(void *); + int (*regfunc)(struct ftrace_event_call *); + void (*unregfunc)(struct ftrace_event_call *); int id; - int (*raw_init)(void); - int (*show_format)(struct ftrace_event_call *call, - struct trace_seq *s); - int (*define_fields)(void); + int (*raw_init)(struct ftrace_event_call *); + int (*show_format)(struct ftrace_event_call *, + struct trace_seq *); + int (*define_fields)(struct ftrace_event_call *); struct list_head fields; int filter_active; struct event_filter *filter; @@ -142,6 +142,8 @@ extern int filter_current_check_discard(struct ftrace_event_call *call, extern int trace_define_field(struct ftrace_event_call *call, char *type, char *name, int offset, int size, int is_signed); +extern int trace_add_event_call(struct ftrace_event_call *call); +extern void trace_remove_event_call(struct ftrace_event_call *call); #define is_signed_type(type) (((type)(-1)) < 0) diff --git a/include/linux/syscalls.h b/include/linux/syscalls.h index 87d06c1..be59d22 100644 --- a/include/linux/syscalls.h +++ b/include/linux/syscalls.h @@ -165,7 +165,7 @@ static void prof_sysexit_disable_##sname(struct ftrace_event_call *event_call) \ struct trace_event enter_syscall_print_##sname = { \ .trace = print_syscall_enter, \ }; \ - static int init_enter_##sname(void) \ + static int init_enter_##sname(struct ftrace_event_call *call) \ { \ int num, id; \ num = syscall_name_to_nr("sys"#sname); \ @@ -201,7 +201,7 @@ static void prof_sysexit_disable_##sname(struct ftrace_event_call *event_call) \ struct trace_event exit_syscall_print_##sname = { \ .trace = print_syscall_exit, \ }; \ - static int init_exit_##sname(void) \ + static int init_exit_##sname(struct ftrace_event_call *call) \ { \ int num, id; \ num = syscall_name_to_nr("sys"#sname); \ diff --git a/include/trace/ftrace.h b/include/trace/ftrace.h index b250b06..6c1b5b1 100644 --- a/include/trace/ftrace.h +++ b/include/trace/ftrace.h @@ -294,10 +294,9 @@ ftrace_raw_output_##call(struct trace_iterator *iter, int flags) \ #undef TRACE_EVENT #define TRACE_EVENT(call, proto, args, tstruct, func, print) \ int \ -ftrace_define_fields_##call(void) \ +ftrace_define_fields_##call(struct ftrace_event_call *event_call) \ { \ struct ftrace_raw_##call field; \ - struct ftrace_event_call *event_call = &event_##call; \ int ret; \ \ __common_field(int, type, 1); \ @@ -411,7 +410,7 @@ static void ftrace_profile_disable_##call(struct ftrace_event_call *event_call)\ * event_trace_printk(_RET_IP_, "<call>: " <fmt>); * } * - * static int ftrace_reg_event_<call>(void) + * static int ftrace_reg_event_<call>(struct ftrace_event_call *unused) * { * int ret; * @@ -422,7 +421,7 @@ static void ftrace_profile_disable_##call(struct ftrace_event_call *event_call)\ * return ret; * } * - * static void ftrace_unreg_event_<call>(void) + * static void ftrace_unreg_event_<call>(struct ftrace_event_call *unused) * { * unregister_trace_<call>(ftrace_event_<call>); * } @@ -455,7 +454,7 @@ static void ftrace_profile_disable_##call(struct ftrace_event_call *event_call)\ * trace_current_buffer_unlock_commit(event, irq_flags, pc); * } * - * static int ftrace_raw_reg_event_<call>(void) + * static int ftrace_raw_reg_event_<call>(struct ftrace_event_call *unused) * { * int ret; * @@ -466,7 +465,7 @@ static void ftrace_profile_disable_##call(struct ftrace_event_call *event_call)\ * return ret; * } * - * static void ftrace_unreg_event_<call>(void) + * static void ftrace_unreg_event_<call>(struct ftrace_event_call *unused) * { * unregister_trace_<call>(ftrace_raw_event_<call>); * } @@ -475,7 +474,7 @@ static void ftrace_profile_disable_##call(struct ftrace_event_call *event_call)\ * .trace = ftrace_raw_output_<call>, <-- stage 2 * }; * - * static int ftrace_raw_init_event_<call>(void) + * static int ftrace_raw_init_event_<call>(struct ftrace_event_call *unused) * { * int id; * @@ -569,7 +568,7 @@ static void ftrace_raw_event_##call(proto) \ trace_nowake_buffer_unlock_commit(event, irq_flags, pc); \ } \ \ -static int ftrace_raw_reg_event_##call(void *ptr) \ +static int ftrace_raw_reg_event_##call(struct ftrace_event_call *unused)\ { \ int ret; \ \ @@ -580,7 +579,7 @@ static int ftrace_raw_reg_event_##call(void *ptr) \ return ret; \ } \ \ -static void ftrace_raw_unreg_event_##call(void *ptr) \ +static void ftrace_raw_unreg_event_##call(struct ftrace_event_call *unused)\ { \ unregister_trace_##call(ftrace_raw_event_##call); \ } \ @@ -589,7 +588,7 @@ static struct trace_event ftrace_event_type_##call = { \ .trace = ftrace_raw_output_##call, \ }; \ \ -static int ftrace_raw_init_event_##call(void) \ +static int ftrace_raw_init_event_##call(struct ftrace_event_call *unused)\ { \ int id; \ \ diff --git a/include/trace/syscall.h b/include/trace/syscall.h index 0cb0362..848b4ae 100644 --- a/include/trace/syscall.h +++ b/include/trace/syscall.h @@ -51,10 +51,10 @@ void set_syscall_enter_id(int num, int id); void set_syscall_exit_id(int num, int id); extern struct trace_event event_syscall_enter; extern struct trace_event event_syscall_exit; -extern int reg_event_syscall_enter(void *ptr); -extern void unreg_event_syscall_enter(void *ptr); -extern int reg_event_syscall_exit(void *ptr); -extern void unreg_event_syscall_exit(void *ptr); +extern int reg_event_syscall_enter(struct ftrace_event_call *call); +extern void unreg_event_syscall_enter(struct ftrace_event_call *call); +extern int reg_event_syscall_exit(struct ftrace_event_call *call); +extern void unreg_event_syscall_exit(struct ftrace_event_call *call); extern int ftrace_format_syscall(struct ftrace_event_call *call, struct trace_seq *s); enum print_line_t print_syscall_enter(struct trace_iterator *iter, int flags); diff --git a/kernel/trace/trace_events.c b/kernel/trace/trace_events.c index b568ade..be701d1 100644 --- a/kernel/trace/trace_events.c +++ b/kernel/trace/trace_events.c @@ -62,9 +62,7 @@ err: } EXPORT_SYMBOL_GPL(trace_define_field); -#ifdef CONFIG_MODULES - -static void trace_destroy_fields(struct ftrace_event_call *call) +void trace_destroy_fields(struct ftrace_event_call *call) { struct ftrace_event_field *field, *next; @@ -76,8 +74,6 @@ static void trace_destroy_fields(struct ftrace_event_call *call) } } -#endif /* CONFIG_MODULES */ - static void ftrace_event_enable_disable(struct ftrace_event_call *call, int enable) { @@ -86,14 +82,14 @@ static void ftrace_event_enable_disable(struct ftrace_event_call *call, if (call->enabled) { call->enabled = 0; tracing_stop_cmdline_record(); - call->unregfunc(call->data); + call->unregfunc(call); } break; case 1: if (!call->enabled) { call->enabled = 1; tracing_start_cmdline_record(); - call->regfunc(call->data); + call->regfunc(call); } break; } @@ -941,7 +937,7 @@ event_create_dir(struct ftrace_event_call *call, struct dentry *d_events, id); if (call->define_fields) { - ret = call->define_fields(); + ret = call->define_fields(call); if (ret < 0) { pr_warning("Could not initialize trace point" " events/%s\n", call->name); @@ -961,27 +957,43 @@ event_create_dir(struct ftrace_event_call *call, struct dentry *d_events, return 0; } -#define for_each_event(event, start, end) \ - for (event = start; \ - (unsigned long)event < (unsigned long)end; \ - event++) +static int __trace_add_event_call(struct ftrace_event_call *call) +{ + struct dentry *d_events; + int ret; -#ifdef CONFIG_MODULES + if (!call->name) + return -EINVAL; -static LIST_HEAD(ftrace_module_file_list); + if (call->raw_init) { + ret = call->raw_init(call); + if (ret < 0) { + if (ret != -ENOSYS) + pr_warning("Could not initialize trace " + "events/%s\n", call->name); + return ret; + } + } -/* - * Modules must own their file_operations to keep up with - * reference counting. - */ -struct ftrace_module_file_ops { - struct list_head list; - struct module *mod; - struct file_operations id; - struct file_operations enable; - struct file_operations format; - struct file_operations filter; -}; + d_events = event_trace_events_dir(); + if (!d_events) + return -ENOENT; + + list_add(&call->list, &ftrace_events); + return event_create_dir(call, d_events, &ftrace_event_id_fops, + &ftrace_enable_fops, &ftrace_event_filter_fops, + &ftrace_event_format_fops); +} + +/* Add an additional event_call dynamically */ +int trace_add_event_call(struct ftrace_event_call *call) +{ + int ret; + mutex_lock(&event_mutex); + ret = __trace_add_event_call(call); + mutex_unlock(&event_mutex); + return ret; +} static void remove_subsystem_dir(const char *name) { @@ -1009,6 +1021,48 @@ static void remove_subsystem_dir(const char *name) } } +static void __trace_remove_event_call(struct ftrace_event_call *call) +{ + ftrace_event_enable_disable(call, 0); + if (call->event) + __unregister_ftrace_event(call->event); + debugfs_remove_recursive(call->dir); + list_del(&call->list); + trace_destroy_fields(call); + destroy_preds(call); + remove_subsystem_dir(call->system); +} + +/* Remove an event_call */ +void trace_remove_event_call(struct ftrace_event_call *call) +{ + mutex_lock(&event_mutex); + __trace_remove_event_call(call); + mutex_unlock(&event_mutex); +} + +#define for_each_event(event, start, end) \ + for (event = start; \ + (unsigned long)event < (unsigned long)end; \ + event++) + +#ifdef CONFIG_MODULES + +static LIST_HEAD(ftrace_module_file_list); + +/* + * Modules must own their file_operations to keep up with + * reference counting. + */ +struct ftrace_module_file_ops { + struct list_head list; + struct module *mod; + struct file_operations id; + struct file_operations enable; + struct file_operations format; + struct file_operations filter; +}; + static struct ftrace_module_file_ops * trace_create_file_ops(struct module *mod) { @@ -1066,7 +1120,7 @@ static void trace_module_add_events(struct module *mod) if (!call->name) continue; if (call->raw_init) { - ret = call->raw_init(); + ret = call->raw_init(call); if (ret < 0) { if (ret != -ENOSYS) pr_warning("Could not initialize trace " @@ -1101,14 +1155,7 @@ static void trace_module_remove_events(struct module *mod) list_for_each_entry_safe(call, p, &ftrace_events, list) { if (call->mod == mod) { found = true; - ftrace_event_enable_disable(call, 0); - if (call->event) - __unregister_ftrace_event(call->event); - debugfs_remove_recursive(call->dir); - list_del(&call->list); - trace_destroy_fields(call); - destroy_preds(call); - remove_subsystem_dir(call->system); + __trace_remove_event_call(call); } } @@ -1226,7 +1273,7 @@ static __init int event_trace_init(void) if (!call->name) continue; if (call->raw_init) { - ret = call->raw_init(); + ret = call->raw_init(call); if (ret < 0) { if (ret != -ENOSYS) pr_warning("Could not initialize trace " diff --git a/kernel/trace/trace_export.c b/kernel/trace/trace_export.c index 956d4bc..71c8d7f 100644 --- a/kernel/trace/trace_export.c +++ b/kernel/trace/trace_export.c @@ -117,10 +117,16 @@ ftrace_format_##call(struct ftrace_event_call *unused, \ #define TRACE_FIELD_SPECIAL(type_item, item, len, cmd) \ cmd; +static int ftrace_raw_init_event(struct ftrace_event_call *event_call) +{ + INIT_LIST_HEAD(&event_call->fields); + init_preds(event_call); + return 0; +} + #undef TRACE_EVENT_FORMAT #define TRACE_EVENT_FORMAT(call, proto, args, fmt, tstruct, tpfmt) \ -int ftrace_define_fields_##call(void); \ -static int ftrace_raw_init_event_##call(void); \ +int ftrace_define_fields_##call(struct ftrace_event_call *c); \ \ struct ftrace_event_call __used \ __attribute__((__aligned__(4))) \ @@ -128,16 +134,10 @@ __attribute__((section("_ftrace_events"))) event_##call = { \ .name = #call, \ .id = proto, \ .system = __stringify(TRACE_SYSTEM), \ - .raw_init = ftrace_raw_init_event_##call, \ + .raw_init = ftrace_raw_init_event, \ .show_format = ftrace_format_##call, \ .define_fields = ftrace_define_fields_##call, \ -}; \ -static int ftrace_raw_init_event_##call(void) \ -{ \ - INIT_LIST_HEAD(&event_##call.fields); \ - init_preds(&event_##call); \ - return 0; \ -} \ +}; #undef TRACE_EVENT_FORMAT_NOFILTER #define TRACE_EVENT_FORMAT_NOFILTER(call, proto, args, fmt, tstruct, \ @@ -184,9 +184,8 @@ __attribute__((section("_ftrace_events"))) event_##call = { \ #undef TRACE_EVENT_FORMAT #define TRACE_EVENT_FORMAT(call, proto, args, fmt, tstruct, tpfmt) \ int \ -ftrace_define_fields_##call(void) \ +ftrace_define_fields_##call(struct ftrace_event_call *event_call) \ { \ - struct ftrace_event_call *event_call = &event_##call; \ struct args field; \ int ret; \ \ diff --git a/kernel/trace/trace_syscalls.c b/kernel/trace/trace_syscalls.c index f837ccc..3451621 100644 --- a/kernel/trace/trace_syscalls.c +++ b/kernel/trace/trace_syscalls.c @@ -210,13 +210,13 @@ void ftrace_syscall_exit(struct pt_regs *regs, long ret) trace_wake_up(); } -int reg_event_syscall_enter(void *ptr) +int reg_event_syscall_enter(struct ftrace_event_call *call) { int ret = 0; int num; char *name; - name = (char *)ptr; + name = (char *)call->data; num = syscall_name_to_nr(name); if (num < 0 || num >= FTRACE_SYSCALL_MAX) return -ENOSYS; @@ -234,12 +234,12 @@ int reg_event_syscall_enter(void *ptr) return ret; } -void unreg_event_syscall_enter(void *ptr) +void unreg_event_syscall_enter(struct ftrace_event_call *call) { int num; char *name; - name = (char *)ptr; + name = (char *)call->data; num = syscall_name_to_nr(name); if (num < 0 || num >= FTRACE_SYSCALL_MAX) return; @@ -251,13 +251,13 @@ void unreg_event_syscall_enter(void *ptr) mutex_unlock(&syscall_trace_lock); } -int reg_event_syscall_exit(void *ptr) +int reg_event_syscall_exit(struct ftrace_event_call *call) { int ret = 0; int num; char *name; - name = (char *)ptr; + name = (char *)call->data; num = syscall_name_to_nr(name); if (num < 0 || num >= FTRACE_SYSCALL_MAX) return -ENOSYS; @@ -275,12 +275,12 @@ int reg_event_syscall_exit(void *ptr) return ret; } -void unreg_event_syscall_exit(void *ptr) +void unreg_event_syscall_exit(struct ftrace_event_call *call) { int num; char *name; - name = (char *)ptr; + name = (char *)call->data; num = syscall_name_to_nr(name); if (num < 0 || num >= FTRACE_SYSCALL_MAX) return; -- Masami Hiramatsu Software Engineer Hitachi Computer Products (America), Inc. 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