From: Wu Fengguang <fengguang.wu@intel.com>
To: Andrew Morton <akpm@linux-foundation.org>
Cc: Greg Kroah-Hartman <gregkh@suse.de>,
Andi Kleen <andi@firstfloor.org>,
Benjamin Herrenschmidt <benh@kernel.crashing.org>,
Christoph Lameter <cl@linux-foundation.org>,
Ingo Molnar <mingo@elte.hu>, Tejun Heo <tj@kernel.org>,
Nick Piggin <npiggin@suse.de>,
KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>,
<stable@kernel.org>, Wu Fengguang <fengguang.wu@intel.com>
Cc: LKML <linux-kernel@vger.kernel.org>
Cc: Linux Memory Management List <linux-mm@kvack.org>,
<linux-fsdevel@vger.kernel.org>
Subject: [PATCH 2/4] devmem: fix kmem write bug on memory holes
Date: Fri, 22 Jan 2010 12:59:16 +0800 [thread overview]
Message-ID: <20100122051517.415742055@intel.com> (raw)
In-Reply-To: 20100122045914.993668874@intel.com
[-- Attachment #1: vwrite-fix.patch --]
[-- Type: text/plain, Size: 1298 bytes --]
write_kmem() used to assume vwrite() always return the full buffer length.
However now vwrite() could return 0 to indicate memory hole. This creates
a bug that "buf" is not advanced accordingly.
Fix it to simply ignore the return value, hence the memory hole.
CC: Andi Kleen <andi@firstfloor.org>
CC: Benjamin Herrenschmidt <benh@kernel.crashing.org>
CC: Christoph Lameter <cl@linux-foundation.org>
CC: Ingo Molnar <mingo@elte.hu>
CC: Tejun Heo <tj@kernel.org>
CC: Nick Piggin <npiggin@suse.de>
CC: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
CC: <stable@kernel.org>
Signed-off-by: Wu Fengguang <fengguang.wu@intel.com>
---
drivers/char/mem.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
--- linux-mm.orig/drivers/char/mem.c 2010-01-11 10:32:32.000000000 +0800
+++ linux-mm/drivers/char/mem.c 2010-01-11 10:32:34.000000000 +0800
@@ -555,7 +555,7 @@ static ssize_t write_kmem(struct file *
err = -EFAULT;
break;
}
- sz = vwrite(kbuf, (char *)p, sz);
+ vwrite(kbuf, (char *)p, sz);
count -= sz;
buf += sz;
virtr += sz;
--
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next prev parent reply other threads:[~2010-01-22 4:59 UTC|newest]
Thread overview: 15+ messages / expand[flat|nested] mbox.gz Atom feed top
2010-01-22 4:59 [PATCH 0/4] devmem and readahead fixes for 2.6.33 Wu Fengguang
2010-01-22 4:59 ` [PATCH 1/4] devmem: check vmalloc address on kmem read/write Wu Fengguang
2010-01-22 4:59 ` Wu Fengguang [this message]
2010-01-22 4:59 ` [PATCH 3/4] vfs: take f_lock on modifying f_mode after open time Wu Fengguang
2010-01-22 4:59 ` [PATCH 4/4] readahead: introduce FMODE_RANDOM for POSIX_FADV_RANDOM Wu Fengguang
2010-01-22 5:31 ` [PATCH 0/4] devmem and readahead fixes for 2.6.33 Greg KH
2010-01-27 0:50 ` Andrew Morton
2010-01-27 1:39 ` Greg KH
2010-01-27 2:45 ` Wu Fengguang
2010-02-03 23:47 ` [stable] " Greg KH
2010-02-04 2:42 ` [stable] [PATCH] devmem: check vmalloc address on kmem read/write Wu Fengguang
2010-02-04 2:43 ` [stable] [PATCH] devmem: fix kmem write bug on memory holes Wu Fengguang
2010-02-04 2:58 ` [stable] [PATCH] devmem: check vmalloc address on kmem read/write KAMEZAWA Hiroyuki
2010-02-04 3:18 ` Wu Fengguang
2010-02-04 3:27 ` KAMEZAWA Hiroyuki
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