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authorSteven Rostedt <srostedt@redhat.com>2009-07-22 23:29:30 -0400
committerSteven Rostedt <rostedt@goodmis.org>2009-07-23 10:07:18 -0400
commit8650ae32ef7045e763825dee6256dde7f331bb85 (patch)
tree546a07e4c5b6fc731b48604769392a671c1fb18e /kernel/trace
parent4c739ff043e5787d97c9691d62cabf7a29e75a9d (diff)
downloadlinux-8650ae32ef7045e763825dee6256dde7f331bb85.tar.bz2
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>
Diffstat (limited to 'kernel/trace')
-rw-r--r--kernel/trace/ftrace.c4
-rw-r--r--kernel/trace/trace.c2
-rw-r--r--kernel/trace/trace_events.c2
3 files changed, 4 insertions, 4 deletions
diff --git a/kernel/trace/ftrace.c b/kernel/trace/ftrace.c
index 1f3ec2afa511..1e1d23c26308 100644
--- a/kernel/trace/ftrace.c
+++ b/kernel/trace/ftrace.c
@@ -1662,7 +1662,7 @@ ftrace_regex_open(struct inode *inode, struct file *file, int enable)
mutex_lock(&ftrace_regex_lock);
if ((file->f_mode & FMODE_WRITE) &&
- !(file->f_flags & O_APPEND))
+ (file->f_flags & O_TRUNC))
ftrace_filter_reset(enable);
if (file->f_mode & FMODE_READ) {
@@ -2577,7 +2577,7 @@ ftrace_graph_open(struct inode *inode, struct file *file)
mutex_lock(&graph_lock);
if ((file->f_mode & FMODE_WRITE) &&
- !(file->f_flags & O_APPEND)) {
+ (file->f_flags & O_TRUNC)) {
ftrace_graph_count = 0;
memset(ftrace_graph_funcs, 0, sizeof(ftrace_graph_funcs));
}
diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c
index 8bc8d8afea6a..d8ef28574aa1 100644
--- a/kernel/trace/trace.c
+++ b/kernel/trace/trace.c
@@ -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)
diff --git a/kernel/trace/trace_events.c b/kernel/trace/trace_events.c
index 53c8fd376a88..23d2972b22d6 100644
--- a/kernel/trace/trace_events.c
+++ b/kernel/trace/trace_events.c
@@ -376,7 +376,7 @@ ftrace_event_seq_open(struct inode *inode, struct file *file)
const struct seq_operations *seq_ops;
if ((file->f_mode & FMODE_WRITE) &&
- !(file->f_flags & O_APPEND))
+ (file->f_flags & O_TRUNC))
ftrace_clear_events();
seq_ops = inode->i_private;