[PATCH 1/4] [PATCH 1/4] tracing: Fix strstrip usage in set_ftrace_pid

[Steven Rostedt <rostedt@goodmis.org>]

[-- Attachment #1: 0001-tracing-Fix-strstrip-usage-in-set_ftrace_pid.patch --]
[-- Type: text/plain, Size: 1378 bytes --]

From: Javier Martinez Canillas <martinez.javier@gmail.com>

The code in writing to set_ftrace_pid crops off whitespace before and
after the passed in string. But the usage of strstrip is incorrect,
and does not do the intended job.

  # echo '  3431   ' > /debug/tracing/set_ftrace_pid
  -bash: echo: write error: Invalid argument

With this fix, the above line now succeeds.

Signed-off-by: Javier Martinez Canillas <martinez.javier@gmail.com>
LKML-Reference: <1256965563.4278.7.camel@laptop>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
---
 kernel/trace/ftrace.c |    7 ++++---
 1 files changed, 4 insertions(+), 3 deletions(-)

diff --git a/kernel/trace/ftrace.c b/kernel/trace/ftrace.c
index 7f9b51e..b29ff29 100644
--- a/kernel/trace/ftrace.c
+++ b/kernel/trace/ftrace.c
@@ -2987,6 +2987,7 @@ ftrace_pid_write(struct file *filp, const char __user *ubuf,
 {
 	char buf[64];
 	long val;
+	char *bufstr;
 	int ret;
 
 	if (cnt >= sizeof(buf))
@@ -3001,11 +3002,11 @@ ftrace_pid_write(struct file *filp, const char __user *ubuf,
 	 * Allow "echo > set_ftrace_pid" or "echo -n '' > set_ftrace_pid"
 	 * to clean the filter quietly.
 	 */
-	strstrip(buf);
-	if (strlen(buf) == 0)
+	bufstr = strstrip(buf);
+	if (strlen(bufstr) == 0)
 		return 1;
 
-	ret = strict_strtol(buf, 10, &val);
+	ret = strict_strtol(bufstr, 10, &val);
 	if (ret < 0)
 		return ret;
 
-- 
1.6.5