From bd1a5c849bdcc5c89e4a6a18216cd2b9a7a8a78f Mon Sep 17 00:00:00 2001 From: Masami Hiramatsu Date: Thu, 13 Aug 2009 16:34:53 -0400 Subject: [PATCH] tracing: Ftrace dynamic ftrace_event_call support MIME-Version: 1.0 Content-Type: text/plain; charset=utf8 Content-Transfer-Encoding: 8bit Add dynamic ftrace_event_call support to ftrace. Trace engines can add new ftrace_event_call to ftrace on the fly. Each operator function of the call takes an 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. [fweisbec@gmail.com: Fixed conflict against latest tracing/core] Signed-off-by: Masami Hiramatsu Cc: Ananth N Mavinakayanahalli Cc: Avi Kivity Cc: Andi Kleen Cc: Christoph Hellwig Cc: Frank Ch. Eigler Cc: H. Peter Anvin Cc: Ingo Molnar Cc: Jason Baron Cc: Jim Keniston Cc: K.Prasad Cc: Lai Jiangshan Cc: Li Zefan Cc: Przemysław Pawełczyk Cc: Roland McGrath Cc: Sam Ravnborg Cc: Srikar Dronamraju Cc: Steven Rostedt Cc: Tom Zanussi Cc: Vegard Nossum LKML-Reference: <20090813203453.31965.71901.stgit@localhost.localdomain> Signed-off-by: Frederic Weisbecker --- include/linux/ftrace_event.h | 19 +++--- include/linux/syscalls.h | 4 +- include/trace/ftrace.h | 16 ++--- include/trace/syscall.h | 11 ++-- kernel/trace/trace_events.c | 121 +++++++++++++++++++++++----------- kernel/trace/trace_export.c | 18 ++--- kernel/trace/trace_syscalls.c | 20 +++--- 7 files changed, 130 insertions(+), 79 deletions(-) diff --git a/include/linux/ftrace_event.h b/include/linux/ftrace_event.h index ace2da9e0a0d..1ab3089b5c59 100644 --- a/include/linux/ftrace_event.h +++ b/include/linux/ftrace_event.h @@ -112,12 +112,12 @@ 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 (*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; @@ -147,11 +147,12 @@ enum { FILTER_PTR_STRING, }; -extern int trace_define_field(struct ftrace_event_call *call, - const char *type, const char *name, - int offset, int size, int is_signed, - int filter_type); extern int trace_define_common_fields(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, + int filter_type); +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 f124c8995555..646102eeff92 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); \ @@ -202,7 +202,7 @@ 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 360a77ad79e1..f2bd7a8f8e8b 100644 --- a/include/trace/ftrace.h +++ b/include/trace/ftrace.h @@ -434,7 +434,7 @@ static void ftrace_profile_disable_##call(struct ftrace_event_call *event_call)\ * event_trace_printk(_RET_IP_, ": " ); * } * - * static int ftrace_reg_event_(void) + * static int ftrace_reg_event_(struct ftrace_event_call *unused) * { * int ret; * @@ -445,7 +445,7 @@ static void ftrace_profile_disable_##call(struct ftrace_event_call *event_call)\ * return ret; * } * - * static void ftrace_unreg_event_(void) + * static void ftrace_unreg_event_(struct ftrace_event_call *unused) * { * unregister_trace_(ftrace_event_); * } @@ -478,7 +478,7 @@ 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_(void) + * static int ftrace_raw_reg_event_(struct ftrace_event_call *unused) * { * int ret; * @@ -489,7 +489,7 @@ static void ftrace_profile_disable_##call(struct ftrace_event_call *event_call)\ * return ret; * } * - * static void ftrace_unreg_event_(void) + * static void ftrace_unreg_event_(struct ftrace_event_call *unused) * { * unregister_trace_(ftrace_raw_event_); * } @@ -498,7 +498,7 @@ static void ftrace_profile_disable_##call(struct ftrace_event_call *event_call)\ * .trace = ftrace_raw_output_, <-- stage 2 * }; * - * static int ftrace_raw_init_event_(void) + * static int ftrace_raw_init_event_(struct ftrace_event_call *unused) * { * int id; * @@ -592,7 +592,7 @@ 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; \ \ @@ -603,7 +603,7 @@ 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); \ } \ @@ -612,7 +612,7 @@ 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 5dc283ba5ae0..e290b86f6167 100644 --- a/include/trace/syscall.h +++ b/include/trace/syscall.h @@ -39,16 +39,19 @@ 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 syscall_enter_format(struct ftrace_event_call *call, struct trace_seq *s); extern int syscall_exit_format(struct ftrace_event_call *call, struct trace_seq *s); extern int syscall_enter_define_fields(struct ftrace_event_call *call); extern int syscall_exit_define_fields(struct ftrace_event_call *call); +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); enum print_line_t print_syscall_exit(struct trace_iterator *iter, int flags); #endif diff --git a/kernel/trace/trace_events.c b/kernel/trace/trace_events.c index d33bcdeffe69..8079bb511c43 100644 --- a/kernel/trace/trace_events.c +++ b/kernel/trace/trace_events.c @@ -27,8 +27,8 @@ DEFINE_MUTEX(event_mutex); LIST_HEAD(ftrace_events); -int trace_define_field(struct ftrace_event_call *call, const char *type, - const char *name, int offset, int size, int is_signed, +int trace_define_field(struct ftrace_event_call *call, char *type, + char *name, int offset, int size, int is_signed, int filter_type) { struct ftrace_event_field *field; @@ -92,9 +92,7 @@ int trace_define_common_fields(struct ftrace_event_call *call) } EXPORT_SYMBOL_GPL(trace_define_common_fields); -#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; @@ -106,8 +104,6 @@ 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) { @@ -116,14 +112,14 @@ 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; } @@ -991,27 +987,43 @@ 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) { @@ -1039,6 +1051,48 @@ 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) { @@ -1096,7 +1150,7 @@ 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 " @@ -1131,14 +1185,7 @@ 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); } } @@ -1256,7 +1303,7 @@ 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 029a91f42287..9cbe7f1930ea 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(struct ftrace_event_call *event_call); \ -static int ftrace_raw_init_event_##call(void); \ \ 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, \ diff --git a/kernel/trace/trace_syscalls.c b/kernel/trace/trace_syscalls.c index 85291c4de406..5931933587e9 100644 --- a/kernel/trace/trace_syscalls.c +++ b/kernel/trace/trace_syscalls.c @@ -193,8 +193,8 @@ int syscall_enter_define_fields(struct ftrace_event_call *call) return ret; for (i = 0; i < meta->nb_args; i++) { - ret = trace_define_field(call, meta->types[i], - meta->args[i], offset, + ret = trace_define_field(call, (char *)meta->types[i], + (char *)meta->args[i], offset, sizeof(unsigned long), 0, FILTER_OTHER); offset += sizeof(unsigned long); @@ -277,13 +277,13 @@ void ftrace_syscall_exit(struct pt_regs *regs, long ret) trace_current_buffer_unlock_commit(event, 0, 0); } -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; @@ -301,12 +301,12 @@ 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; @@ -318,13 +318,13 @@ 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; @@ -342,12 +342,12 @@ 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; -- 2.34.1