2009-06-27 00:35:19

by Kevin Cernekee

Subject: [PATCH] UBIFS: Fix integer overflow warnings

This warning was observed on MIPS32 using 2.6.31-rc1 and gcc-4.2.0:

fs/ubifs/io.c: In function 'ubifs_wbuf_init':
fs/ubifs/io.c:860: warning: integer overflow in expression
fs/ubifs/io.c:860: warning: integer overflow in expression
fs/ubifs/io.c:860: warning: integer overflow in expression

Signed-off-by: Kevin Cernekee <[email protected]>
---
index bc58571..184157e 100644
--- a/fs/ubifs/io.c
+++ b/fs/ubifs/io.c
@@ -857,7 +857,8 @@ int ubifs_wbuf_init(struct ubifs_info *c, struct ubifs_wbuf *wbuf)
* and hard limits.
*/
hardlimit = ktime_set(DEFAULT_WBUF_TIMEOUT_SECS, 0);
- wbuf->delta = (DEFAULT_WBUF_TIMEOUT_SECS * NSEC_PER_SEC) * 2 / 10;
+ wbuf->delta = ((unsigned long long)DEFAULT_WBUF_TIMEOUT_SECS *
+ NSEC_PER_SEC) * 2 / 10;
wbuf->softlimit = ktime_sub_ns(hardlimit, wbuf->delta);
hrtimer_set_expires_range_ns(&wbuf->timer, wbuf->softlimit,
wbuf->delta);
--

2009-06-27 11:38:12

by Artem Bityutskiy

Subject: Re: [PATCH] UBIFS: Fix integer overflow warnings

On Fri, 2009-06-26 at 17:10 -0700, Kevin Cernekee wrote:
> This warning was observed on MIPS32 using 2.6.31-rc1 and gcc-4.2.0:
>
> fs/ubifs/io.c: In function 'ubifs_wbuf_init':
> fs/ubifs/io.c:860: warning: integer overflow in expression
> fs/ubifs/io.c:860: warning: integer overflow in expression
> fs/ubifs/io.c:860: warning: integer overflow in expression
>
> Signed-off-by: Kevin Cernekee <[email protected]>

Thanks for the patch,

however we there is already a fix for this. I'll send it to
Linus soon.

http://git.infradead.org/ubifs-2.6.git?a=commit;h=4804e8b700504978eb4b9397f818ba7ba1227a15

--
Best regards,
Artem Bityutskiy (Битюцкий Артём)