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tracing/events: clean up for ftrace_set_clr_event()

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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 d6bf81ef0f
("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 <lizf@cn.fujitsu.com>
Acked-by: Steven Rostedt <rostedt@goodmis.org>
Acked-by: Frederic Weisbecker <fweisbec@gmail.com>
LKML-Reference: <4A03998E.3020503@cn.fujitsu.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
This commit is contained in:
Li Zefan 2009-05-08 10:31:42 +08:00 committed by Ingo Molnar
parent 74f4fd2166
commit 8f31bfe538
1 changed files with 47 additions and 81 deletions
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128
kernel/trace/trace_events.c
View file

@ -111,35 +111,14 @@ 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;
char *event = NULL, *sub = NULL, *match;
int ret = -EINVAL;
/*
* The buf format can be <subsystem>:<event-name>
* *:<event-name> means any event by that name.
* :<event-name> is the same.
*
* <subsystem>:* means all events in that subsystem
* <subsystem>: means the same.
*
* <name> (no ':') means all events in a subsystem with
* the name <name> or any event that matches <name>
*/
match = strsep(&buf, ":");
if (buf) {
sub = match;
event = buf;
match = NULL;
if (!strlen(sub) || strcmp(sub, "*") == 0)
sub = NULL;
if (!strlen(event) || strcmp(event, "*") == 0)
event = NULL;
}
int ret;
mutex_lock(&event_mutex);
list_for_each_entry(call, &ftrace_events, list) {
@ -167,6 +146,37 @@ static int ftrace_set_clr_event(char *buf, int set)
return ret;
}
static int ftrace_set_clr_event(char *buf, int set)
{
char *event = NULL, *sub = NULL, *match;
/*
* The buf format can be <subsystem>:<event-name>
* *:<event-name> means any event by that name.
* :<event-name> is the same.
*
* <subsystem>:* means all events in that subsystem
* <subsystem>: means the same.
*
* <name> (no ':') means all events in a subsystem with
* the name <name> or any event that matches <name>
*/
match = strsep(&buf, ":");
if (buf) {
sub = match;
event = buf;
match = NULL;
if (!strlen(sub) || strcmp(sub, "*") == 0)
sub = NULL;
if (!strlen(event) || strcmp(event, "*") == 0)
event = NULL;
}
return __ftrace_set_clr_event(match, sub, event, set);
}
/* 128 should be much more than enough */
#define EVENT_BUF_SIZE 127
@ -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;