>From 27f50827e5e81f2a30544b72c1d54c3ee86835cf Mon Sep 17 00:00:00 2001
From: Arun KS <[email protected]>
Date: Mon, 19 Aug 2013 12:06:33 +0530
Subject: SeqFile: Fix overflow condition
seq_path()/seq_commit() is treating a d_path() failure as an overflow
condition, but it isn't.
Signed-off-by: Arun KS <[email protected]>
---
fs/seq_file.c | 6 +++---
include/linux/seq_file.h | 12 +++++++-----
2 files changed, 10 insertions(+), 8 deletions(-)
diff --git a/fs/seq_file.c b/fs/seq_file.c
index 3135c25..6a33f9c 100644
--- a/fs/seq_file.c
+++ b/fs/seq_file.c
@@ -463,7 +463,7 @@ int seq_path(struct seq_file *m, const struct path
*path, const char *esc)
{
char *buf;
size_t size = seq_get_buf(m, &buf);
- int res = -1;
+ int res = -ENOBUFS;
if (size) {
char *p = d_path(path, buf, size);
@@ -487,7 +487,7 @@ int seq_path_root(struct seq_file *m, const struct
path *path,
{
char *buf;
size_t size = seq_get_buf(m, &buf);
- int res = -ENAMETOOLONG;
+ int res = -ENOBUFS;
if (size) {
char *p;
@@ -516,7 +516,7 @@ int seq_dentry(struct seq_file *m, struct dentry
*dentry, const char *esc)
{
char *buf;
size_t size = seq_get_buf(m, &buf);
- int res = -1;
+ int res = -ENOBUFS;
if (size) {
char *p = dentry_path(dentry, buf, size);
diff --git a/include/linux/seq_file.h b/include/linux/seq_file.h
index 4e32edc..43f51a0 100644
--- a/include/linux/seq_file.h
+++ b/include/linux/seq_file.h
@@ -7,6 +7,7 @@
#include <linux/mutex.h>
#include <linux/cpumask.h>
#include <linux/nodemask.h>
+#include <linux/errno.h>
struct seq_operations;
struct file;
@@ -66,16 +67,17 @@ static inline size_t seq_get_buf(struct seq_file
*m, char **bufp)
* @num: the number of bytes to commit
*
* Commit @num bytes of data written to a buffer previously acquired
- * by seq_buf_get. To signal an error condition, or that the data
- * didn't fit in the available space, pass a negative @num value.
+ * by seq_buf_get. To signal an overflow condition(data didn't fit
+ * in the available space), pass -ENOBUFS and for other errors pass a
+ * negative @num value.
*/
static inline void seq_commit(struct seq_file *m, int num)
{
- if (num < 0) {
- m->count = m->size;
- } else {
+ if (num >= 0) {
BUG_ON(m->count + num > m->size);
m->count += num;
+ } else if (num == -ENOBUFS)
+ m->count = m->size;
}
}
--
1.7.6
On Mon, 19 Aug 2013 17:02:37 +0530 Arun KS <[email protected]> wrote:
> seq_path()/seq_commit() is treating a d_path() failure as an overflow
> condition, but it isn't.
This is too brief. When fixing a bug please always describe the
user-visible effects of the bug. And unless it's utterly obvious,
provide a description of how you set about fixing that bug.
Hi Andrew,
On Tue, Aug 20, 2013 at 4:35 AM, Andrew Morton
<[email protected]> wrote:
> On Mon, 19 Aug 2013 17:02:37 +0530 Arun KS <[email protected]> wrote:
>
>> seq_path()/seq_commit() is treating a d_path() failure as an overflow
>> condition, but it isn't.
>
> This is too brief. When fixing a bug please always describe the
> user-visible effects of the bug. And unless it's utterly obvious,
> provide a description of how you set about fixing that bug.
>
I ll address this and will send a patch soon.
Thanks,
Arun