From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1425489AbdDUTmB (ORCPT ); Fri, 21 Apr 2017 15:42:01 -0400 Received: from mail-qt0-f195.google.com ([209.85.216.195]:35148 "EHLO mail-qt0-f195.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1425451AbdDUTl4 (ORCPT ); Fri, 21 Apr 2017 15:41:56 -0400 MIME-Version: 1.0 In-Reply-To: <20170419203819.21951-1-jeremy.lefaure@lse.epita.fr> References: <20170419203819.21951-1-jeremy.lefaure@lse.epita.fr> From: Andy Shevchenko Date: Fri, 21 Apr 2017 22:41:54 +0300 Message-ID: Subject: Re: [PATCH] FS-Cache: print hexadecimal value for special cookies type To: =?UTF-8?B?SsOpcsOpbXkgTGVmYXVyZQ==?= Cc: David Howells , linux-cachefs@redhat.com, "linux-kernel@vger.kernel.org" Content-Type: text/plain; charset=UTF-8 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Transfer-Encoding: 8bit X-MIME-Autoconverted: from quoted-printable to 8bit by mail.home.local id v3LJgAcI008602 On Wed, Apr 19, 2017 at 11:38 PM, Jérémy Lefaure wrote: > When building object-list.o, gcc 6 raises a warning on the sprintf call > in fscache_objlist_show: > > CC fs/fscache/object-list.o > fs/fscache/object-list.c: In function ‘fscache_objlist_show’: > fs/fscache/object-list.c:265:19: warning: ‘sprintf’ may write a > terminating nul past the end of the destination [-Wformat-overflow=] > sprintf(_type, "%02u", cookie->def->type); > ^~~~~~ > fs/fscache/object-list.c:265:4: note: ‘sprintf’ output between 3 and 4 > bytes into a destination of size 3 > sprintf(_type, "%02u", cookie->def->type); > ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ > > Moreover, the documentation says that we should have an hex value for > special cookies (see Documentation/filesystems/caching/fscache.txt). > > Printing hexadecimal value for special cookies fixes the overflow > warning and complies with the documentation. If this is used by some user space tool the safest fix is to print in BCD and fix documentation. > Signed-off-by: Jérémy Lefaure > --- > fs/fscache/object-list.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/fs/fscache/object-list.c b/fs/fscache/object-list.c > index 67f940892ef8..d51303124889 100644 > --- a/fs/fscache/object-list.c > +++ b/fs/fscache/object-list.c > @@ -262,7 +262,7 @@ static int fscache_objlist_show(struct seq_file *m, void *v) > type = "DT"; > break; > default: > - sprintf(_type, "%02u", cookie->def->type); > + sprintf(_type, "%02x", cookie->def->type); > type = _type; > break; > } > -- > 2.12.2 > -- With Best Regards, Andy Shevchenko