Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753586Ab0HWXC2 (ORCPT ); Mon, 23 Aug 2010 19:02:28 -0400 Received: from fgwmail7.fujitsu.co.jp ([192.51.44.37]:45821 "EHLO fgwmail7.fujitsu.co.jp" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751318Ab0HWXCZ (ORCPT ); Mon, 23 Aug 2010 19:02:25 -0400 X-SecurityPolicyCheck-FJ: OK by FujitsuOutboundMailChecker v1.3.1 From: KOSAKI Motohiro To: Neil Horman Subject: Re: [RFC PATCH v3] core_pattern: fix long parameters was truncated by core_pattern handler Cc: kosaki.motohiro@jp.fujitsu.com, Xiaotian Feng , linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org, Alexander Viro , Andrew Morton , Oleg Nesterov , Roland McGrath In-Reply-To: <20100823110719.GA12906@hmsreliant.think-freely.org> References: <1282296958-2427-1-git-send-email-dfeng@redhat.com> <20100823110719.GA12906@hmsreliant.think-freely.org> Message-Id: <20100824080119.6032.A69D9226@jp.fujitsu.com> MIME-Version: 1.0 Content-Type: text/plain; charset="US-ASCII" Content-Transfer-Encoding: 7bit X-Mailer: Becky! ver. 2.50.07 [ja] Date: Tue, 24 Aug 2010 08:02:22 +0900 (JST) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2180 Lines: 53 > On Fri, Aug 20, 2010 at 05:35:58PM +0800, Xiaotian Feng wrote: > > We met a parameter truncated issue, consider following: > > > echo "|/root/core_pattern_pipe_test %p /usr/libexec/blah-blah-blah \ > > %s %c %p %u %g 11 12345678901234567890123456789012345678 %t" > \ > > /proc/sys/kernel/core_pattern > > > > This is okay because the strings is less than CORENAME_MAX_SIZE. > > "cat /proc/sys/kernel/core_pattern" shows the whole string. but > > after we run core_pattern_pipe_test in man page, we found last > > parameter was truncated like below: > > argc[10]=<12807486> > > > > The root cause is core_pattern allows % specifiers, which need to be > > replaced during parse time, but the replace may expand the strings > > to larger than CORENAME_MAX_SIZE. So if the last parameter is % > > specifiers, the replace code is using snprintf(out_ptr, out_end - out_ptr, ...), > > this will write out of corename array. > > > > Changes since v2: > > Introduced generic function cn_printf and make format_corename remember the time > > has been expanded. > > > > Changes since v1: > > This patch allocates corename at runtime, if the replace doesn't have enough > > memory, expand the corename dynamically. > > > > Signed-off-by: Xiaotian Feng > > Cc: Alexander Viro > > Cc: Andrew Morton > > Cc: Oleg Nesterov > > Cc: KOSAKI Motohiro > > Cc: Neil Horman > > Cc: Roland McGrath > > --- > > fs/exec.c | 180 ++++++++++++++++++++++++++++++++++++++++-------------------- > > 1 files changed, 120 insertions(+), 60 deletions(-) > > > This looks alot cleaner. Thanks! > Reviewed-by: Neil Horman > Unfortunatelly, I have no time to review deeply this one. but I see my test works. Also, I'd like to say I like this one. Thanks. -- 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/