From: "Steven Rostedt (VMware)" <rostedt@xxxxxxxxxxx>
In order to make tracefs_function_filter() thread safe, add a pthread
mutex around the entire function to only let one thread access it at a
time.
Signed-off-by: Steven Rostedt (VMware) <rostedt@xxxxxxxxxxx>
---
src/tracefs-tools.c | 12 +++++++++---
1 file changed, 9 insertions(+), 3 deletions(-)
diff --git a/src/tracefs-tools.c b/src/tracefs-tools.c
index 6d03b4856a63..7e191e207867 100644
--- a/src/tracefs-tools.c
+++ b/src/tracefs-tools.c
@@ -13,6 +13,7 @@
#include <regex.h>
#include <dirent.h>
#include <limits.h>
+#include <pthread.h>
#include <errno.h>
#include "tracefs.h"
@@ -22,6 +23,8 @@
#define TRACE_FILTER "set_ftrace_filter"
#define TRACE_FILTER_LIST "available_filter_functions"
+static pthread_mutex_t filter_lock = PTHREAD_MUTEX_INITIALIZER;
+
static const char * const options_map[] = {
"unknown",
"annotate",
@@ -867,15 +870,16 @@ int tracefs_function_filter(struct tracefs_instance *instance, const char **filt
char *ftrace_filter_path;
bool reset = flags & TRACEFS_FL_RESET;
int open_flags;
- int ret;
+ int ret = 1;
int fd;
+ pthread_mutex_lock(&filter_lock);
if (!filters)
- return 1;
+ goto out;
func_filters = make_func_filters(filters);
if (!func_filters)
- return 1;
+ goto out;
/* Make sure errs is NULL to start with, realloc() depends on it. */
if (errs)
@@ -906,6 +910,8 @@ int tracefs_function_filter(struct tracefs_instance *instance, const char **filt
out_free:
free_func_list(func_list);
free_func_filters(func_filters);
+ out:
+ pthread_mutex_unlock(&filter_lock);
return ret;
}
--
2.30.1
|