tracing: only truncate ftrace files when O_TRUNC is set

The current code will truncate the ftrace files contents if O_APPEND
is not set and the file is opened in write mode. This is incorrect.
It should only truncate the file if O_TRUNC is set. Otherwise
if one of these files is opened by a C program with fopen "r+",
it will incorrectly truncate the file.

Reported-by: Jiri Olsa <jolsa@redhat.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
This commit is contained in:
Steven Rostedt
2009-07-22 23:29:30 -04:00
committed by Steven Rostedt
parent 4c739ff043
commit 8650ae32ef
3 changed files with 4 additions and 4 deletions

View File

@@ -2031,7 +2031,7 @@ static int tracing_open(struct inode *inode, struct file *file)
/* If this file was open for write, then erase contents */
if ((file->f_mode & FMODE_WRITE) &&
!(file->f_flags & O_APPEND)) {
(file->f_flags & O_TRUNC)) {
long cpu = (long) inode->i_private;
if (cpu == TRACE_PIPE_ALL_CPU)