From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from psmtp.com (na3sys010amx157.postini.com [74.125.245.157]) by kanga.kvack.org (Postfix) with SMTP id 6AAFB6B0033 for ; Tue, 20 Aug 2013 00:00:13 -0400 (EDT) Message-ID: <5212E98E.9010902@asianux.com> Date: Tue, 20 Aug 2013 11:59:10 +0800 From: Chen Gang MIME-Version: 1.0 Subject: [PATCH 3/3] mm/shmem.c: check the return value of mpol_to_str() References: <5212E8DF.5020209@asianux.com> <5212E910.7030609@asianux.com> <5212E948.8000401@asianux.com> In-Reply-To: <5212E948.8000401@asianux.com> Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Sender: owner-linux-mm@kvack.org List-ID: To: Mel Gorman , kosaki.motohiro@jp.fujitsu.com, riel@redhat.com, hughd@google.com, xemul@parallels.com, Cyrill Gorcunov , rientjes@google.com, Wanpeng Li hughd@google.com Cc: Andrew Morton , linux-mm@kvack.org, "linux-kernel@vger.kernel.org" mpol_to_str() may fail, and not fill the buffer (e.g. -EINVAL), so need check about it, or buffer may not be zero based, and next seq_printf() will cause issue. Also print related warning when the buffer space is not enough. Signed-off-by: Chen Gang --- mm/shmem.c | 15 ++++++++++++++- 1 files changed, 14 insertions(+), 1 deletions(-) diff --git a/mm/shmem.c b/mm/shmem.c index 75010ba..eb4eec8 100644 --- a/mm/shmem.c +++ b/mm/shmem.c @@ -886,11 +886,24 @@ redirty: static void shmem_show_mpol(struct seq_file *seq, struct mempolicy *mpol) { char buffer[64]; + int ret; if (!mpol || mpol->mode == MPOL_DEFAULT) return; /* show nothing */ - mpol_to_str(buffer, sizeof(buffer), mpol); + ret = mpol_to_str(buffer, sizeof(buffer), mpol); + if (ret < 0) + switch (ret) { + case -ENOSPC: + printk(KERN_WARNING + "in %s: string is truncated in mpol_to_str().\n", + __func__); + default: + printk(KERN_ERR + "in %s: call mpol_to_str() fail, errcode: %d. buffer: %p, size: %zu, pol: %p\n", + __func__, ret, buffer, sizeof(buffer), mpol); + return; + } seq_printf(seq, ",mpol=%s", buffer); } -- 1.7.7.6 -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: email@kvack.org