From: Steven Rostedt <rostedt@goodmis.org>
To: linux-kernel@vger.kernel.org
Cc: Ingo Molnar <mingo@elte.hu>,
Andrew Morton <akpm@linux-foundation.org>,
Thomas Gleixner <tglx@linutronix.de>,
Frederic Weisbecker <fweisbec@gmail.com>
Subject: [PATCH 2/4] tracing: only truncate ftrace files when O_TRUNC is set
Date: Thu, 23 Jul 2009 17:00:49 -0400 [thread overview]
Message-ID: <20090723210220.508042243@goodmis.org> (raw)
In-Reply-To: 20090723210047.294710482@goodmis.org
[-- Attachment #1: 0002-tracing-only-truncate-ftrace-files-when-O_TRUNC-is-s.patch --]
[-- Type: text/plain, Size: 2324 bytes --]
From: Steven Rostedt <srostedt@redhat.com>
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>
---
kernel/trace/ftrace.c | 4 ++--
kernel/trace/trace.c | 2 +-
kernel/trace/trace_events.c | 2 +-
3 files changed, 4 insertions(+), 4 deletions(-)
diff --git a/kernel/trace/ftrace.c b/kernel/trace/ftrace.c
index 1f3ec2a..1e1d23c 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 8bc8d8a..d8ef285 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 53c8fd3..23d2972 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;
--
1.6.3.3
--
next prev parent reply other threads:[~2009-07-23 21:02 UTC|newest]
Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top
2009-07-23 21:00 [PATCH 0/4] [GIT PULL][2.6.31] tracing: more fixes Steven Rostedt
2009-07-23 21:00 ` [PATCH 1/4] tracing: show proper address for trace-printk format Steven Rostedt
2009-07-23 21:00 ` Steven Rostedt [this message]
2009-07-23 21:00 ` [PATCH 3/4] ftrace: Fix the conditional that updates $ref_func Steven Rostedt
2009-07-23 21:00 ` [PATCH 4/4] ftrace: Only update $offset when we update $ref_func Steven Rostedt
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