From bd1a5c849bdcc5c89e4a6a18216cd2b9a7a8a78f Mon Sep 17 00:00:00 2001 From: Masami Hiramatsu Date: Thu, 13 Aug 2009 16:34:53 -0400 Subject: tracing: Ftrace dynamic ftrace_event_call support MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 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 --- kernel/trace/trace_events.c | 121 +++++++++++++++++++++++++++++------------- kernel/trace/trace_export.c | 18 +++---- kernel/trace/trace_syscalls.c | 20 +++---- 3 files changed, 103 insertions(+), 56 deletions(-) (limited to 'kernel/trace') 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; -- cgit v1.2.2