Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752118Ab3HTEAN (ORCPT ); Tue, 20 Aug 2013 00:00:13 -0400 Received: from intranet.asianux.com ([58.214.24.6]:62589 "EHLO intranet.asianux.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751875Ab3HTEAM (ORCPT ); Tue, 20 Aug 2013 00:00:12 -0400 X-Spam-Score: -101.1 Message-ID: <5212E98E.9010902@asianux.com> Date: Tue, 20 Aug 2013 11:59:10 +0800 From: Chen Gang User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:17.0) Gecko/20130110 Thunderbird/17.0.2 MIME-Version: 1.0 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" 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: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1414 Lines: 49 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 from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/