From 8f31bfe538ebafac187d2d4465a92e1d9ee6d8c2 Mon Sep 17 00:00:00 2001 From: Li Zefan Date: Fri, 8 May 2009 10:31:42 +0800 Subject: [PATCH] tracing/events: clean up for ftrace_set_clr_event() Add a helper function __ftrace_set_clr_event(), and replace some ftrace_set_clr_event() calls with this helper, thus we don't need any kstrdup() or kmalloc(). As a side effect, this patch fixes an issue in self tests code, which is similar to the one fixed in commit d6bf81ef0f7474434c2a049e8bf3c9146a14dd96 ("tracing: append ":*" to internal setting of system events") It's a small issue and won't cause any bug in fact, but we should do things right anyway. [ Impact: prevent spurious event-enabling in tracing self-tests ] Signed-off-by: Li Zefan Acked-by: Steven Rostedt Acked-by: Frederic Weisbecker LKML-Reference: <4A03998E.3020503@cn.fujitsu.com> Signed-off-by: Ingo Molnar --- kernel/trace/trace_events.c | 126 +++++++++++++----------------------- 1 file changed, 46 insertions(+), 80 deletions(-) diff --git a/kernel/trace/trace_events.c b/kernel/trace/trace_events.c index 8d0fae3af595..45f1099386b6 100644 --- a/kernel/trace/trace_events.c +++ b/kernel/trace/trace_events.c @@ -111,11 +111,44 @@ static void ftrace_event_enable_disable(struct ftrace_event_call *call, } } -static int ftrace_set_clr_event(char *buf, int set) +/* + * __ftrace_set_clr_event(NULL, NULL, NULL, set) will set/unset all events. + */ +static int __ftrace_set_clr_event(const char *match, const char *sub, + const char *event, int set) { struct ftrace_event_call *call; + int ret; + + mutex_lock(&event_mutex); + list_for_each_entry(call, &ftrace_events, list) { + + if (!call->name || !call->regfunc) + continue; + + if (match && + strcmp(match, call->name) != 0 && + strcmp(match, call->system) != 0) + continue; + + if (sub && strcmp(sub, call->system) != 0) + continue; + + if (event && strcmp(event, call->name) != 0) + continue; + + ftrace_event_enable_disable(call, set); + + ret = 0; + } + mutex_unlock(&event_mutex); + + return ret; +} + +static int ftrace_set_clr_event(char *buf, int set) +{ char *event = NULL, *sub = NULL, *match; - int ret = -EINVAL; /* * The buf format can be : @@ -141,30 +174,7 @@ static int ftrace_set_clr_event(char *buf, int set) event = NULL; } - mutex_lock(&event_mutex); - list_for_each_entry(call, &ftrace_events, list) { - - if (!call->name || !call->regfunc) - continue; - - if (match && - strcmp(match, call->name) != 0 && - strcmp(match, call->system) != 0) - continue; - - if (sub && strcmp(sub, call->system) != 0) - continue; - - if (event && strcmp(event, call->name) != 0) - continue; - - ftrace_event_enable_disable(call, set); - - ret = 0; - } - mutex_unlock(&event_mutex); - - return ret; + return __ftrace_set_clr_event(match, sub, event, set); } /* 128 should be much more than enough */ @@ -408,18 +418,14 @@ system_enable_read(struct file *filp, char __user *ubuf, size_t cnt, struct ftrace_event_call *call; char buf[2]; int set = -1; - int all = 0; int ret; - if (system[0] == '*') - all = 1; - mutex_lock(&event_mutex); list_for_each_entry(call, &ftrace_events, list) { if (!call->name || !call->regfunc) continue; - if (!all && strcmp(call->system, system) != 0) + if (system && strcmp(call->system, system) != 0) continue; /* @@ -480,7 +486,6 @@ system_enable_write(struct file *filp, const char __user *ubuf, size_t cnt, { const char *system = filp->private_data; unsigned long val; - char *command; char buf[64]; ssize_t ret; @@ -500,30 +505,16 @@ system_enable_write(struct file *filp, const char __user *ubuf, size_t cnt, if (ret < 0) return ret; - switch (val) { - case 0: - case 1: - break; - - default: + if (val != 0 && val != 1) return -EINVAL; - } - /* +3 for the ":*\0" */ - command = kmalloc(strlen(system)+3, GFP_KERNEL); - if (!command) - return -ENOMEM; - sprintf(command, "%s:*", system); - - ret = ftrace_set_clr_event(command, val); + ret = __ftrace_set_clr_event(NULL, system, NULL, val); if (ret) - goto out_free; + goto out; ret = cnt; - out_free: - kfree(command); - +out: *ppos += cnt; return ret; @@ -1181,7 +1172,7 @@ static __init int event_trace_init(void) &ftrace_show_header_fops); trace_create_file("enable", 0644, d_events, - "*", &ftrace_system_enable_fops); + NULL, &ftrace_system_enable_fops); for_each_event(call, __start_ftrace_events, __stop_ftrace_events) { /* The linker may leave blanks */ @@ -1259,7 +1250,6 @@ static __init void event_trace_self_tests(void) { struct ftrace_event_call *call; struct event_subsystem *system; - char *sysname; int ret; pr_info("Running tests on trace events:\n"); @@ -1305,14 +1295,7 @@ static __init void event_trace_self_tests(void) pr_info("Testing event system %s: ", system->name); - /* ftrace_set_clr_event can modify the name passed in. */ - sysname = kstrdup(system->name, GFP_KERNEL); - if (WARN_ON(!sysname)) { - pr_warning("Can't allocate memory, giving up!\n"); - return; - } - ret = ftrace_set_clr_event(sysname, 1); - kfree(sysname); + ret = __ftrace_set_clr_event(NULL, system->name, NULL, 1); if (WARN_ON_ONCE(ret)) { pr_warning("error enabling system %s\n", system->name); @@ -1321,14 +1304,7 @@ static __init void event_trace_self_tests(void) event_test_stuff(); - sysname = kstrdup(system->name, GFP_KERNEL); - if (WARN_ON(!sysname)) { - pr_warning("Can't allocate memory, giving up!\n"); - return; - } - ret = ftrace_set_clr_event(sysname, 0); - kfree(sysname); - + ret = __ftrace_set_clr_event(NULL, system->name, NULL, 0); if (WARN_ON_ONCE(ret)) pr_warning("error disabling system %s\n", system->name); @@ -1341,15 +1317,8 @@ static __init void event_trace_self_tests(void) pr_info("Running tests on all trace events:\n"); pr_info("Testing all events: "); - sysname = kmalloc(4, GFP_KERNEL); - if (WARN_ON(!sysname)) { - pr_warning("Can't allocate memory, giving up!\n"); - return; - } - memcpy(sysname, "*:*", 4); - ret = ftrace_set_clr_event(sysname, 1); + ret = __ftrace_set_clr_event(NULL, NULL, NULL, 1); if (WARN_ON_ONCE(ret)) { - kfree(sysname); pr_warning("error enabling all events\n"); return; } @@ -1357,10 +1326,7 @@ static __init void event_trace_self_tests(void) event_test_stuff(); /* reset sysname */ - memcpy(sysname, "*:*", 4); - ret = ftrace_set_clr_event(sysname, 0); - kfree(sysname); - + ret = __ftrace_set_clr_event(NULL, NULL, NULL, 0); if (WARN_ON_ONCE(ret)) { pr_warning("error disabling all events\n"); return; -- 2.30.2