From: Eric Dumazet <eric.dumazet@gmail.com>
To: Dave Jones <davej@redhat.com>,
Andrew Morton <akpm@linux-foundation.org>,
Wu Fengguang <fengguang.wu@intel.com>
Cc: linux-kernel <linux-kernel@vger.kernel.org>
Subject: [PATCH] /dev/mem: Allow rewinding
Date: Mon, 05 Apr 2010 23:19:05 +0200 [thread overview]
Message-ID: <1270502345.9013.31.camel@edumazet-laptop> (raw)
In-Reply-To: <1270501448.9013.23.camel@edumazet-laptop>
Le lundi 05 avril 2010 à 23:04 +0200, Eric Dumazet a écrit :
> Andrew, commit dcefafb6ac90ece8d68a6c203105f3d313e52da4 seems to be the
> problem.
>
> It breaks rewinds (negative offsets to lseek (... SEEK_CUR))
>
Here is a patch to make rewind working again on /dev/mem
[PATCH] /dev/mem: Allow rewinding
commit dcefafb6 (/dev/mem: dont allow seek to last page)
inadvertently disabled rewinding on /dev/mem.
This broke x86info for example.
Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
---
diff --git a/drivers/char/mem.c b/drivers/char/mem.c
index 1f3215a..3973a1d 100644
--- a/drivers/char/mem.c
+++ b/drivers/char/mem.c
@@ -710,11 +710,6 @@ static loff_t memory_lseek(struct file *file, loff_t offset, int orig)
switch (orig) {
case SEEK_CUR:
offset += file->f_pos;
- if ((unsigned long long)offset <
- (unsigned long long)file->f_pos) {
- ret = -EOVERFLOW;
- break;
- }
case SEEK_SET:
/* to avoid userland mistaking f_pos=-9 as -EBADF=-9 */
if ((unsigned long long)offset >= ~0xFFFULL) {
next prev parent reply other threads:[~2010-04-05 21:19 UTC|newest]
Thread overview: 8+ messages / expand[flat|nested] mbox.gz Atom feed top
2010-04-05 20:24 [BUG] x86info fails on 2.6.34 ? Eric Dumazet
2010-04-05 21:04 ` Eric Dumazet
2010-04-05 21:19 ` Eric Dumazet [this message]
2010-04-06 5:15 ` [PATCH] /dev/mem: Allow rewinding Wu Fengguang
2010-04-06 5:30 ` Américo Wang
2010-04-06 5:43 ` Wu Fengguang
2010-04-06 6:24 ` Américo Wang
2010-04-06 6:21 ` Eric Dumazet
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