Received-SPF: pass (google.com: domain of linux-kernel+bounces-307-linux.lists.archive=gmail.com@vger.kernel.org designates 2604:1380:4601:e00::3 as permitted sender) client-ip=2604:1380:4601:e00::3;
Date: Fri, 15 Dec 2023 09:10:21 +0800
From: Philip Li <philip.li@intel.com>
To: Kees Cook <keescook@chromium.org>
CC: kernel test robot <lkp@intel.com>, <oe-kbuild-all@lists.linux.dev>,
	<linux-kernel@vger.kernel.org>, Andrew Morton <akpm@linux-foundation.org>,
	Linux Memory Management List <linux-mm@kvack.org>, "Gustavo A. R. Silva"
	<gustavoars@kernel.org>, Peter Oberparleiter <oberpar@linux.ibm.com>,
	<linux-doc@vger.kernel.org>, <linux-hardening@vger.kernel.org>
Subject: Re: kernel/gcov/fs.c:103: warning: Excess struct member 'buffer'
 description in 'gcov_iterator'
Message-ID: <ZXunfWqei+vXUCnp@rli9-mobl>
References: <202312150432.oBngC94A-lkp@intel.com>
 <202312141344.9E41E46584@keescook>
Content-Type: text/plain; charset="us-ascii"
Content-Disposition: inline
In-Reply-To: <202312141344.9E41E46584@keescook>
Precedence: bulk
MIME-Version: 1.0
X-MS-Exchange-AntiSpam-MessageData-ChunkCount: 1
X-MS-Exchange-AntiSpam-MessageData-0: =?us-ascii?Q?EdmHb60UR1MBqtdsiXCiZs3h/163beFThmL/aDaGItKDvxgzAWgKGixuNEKb?=
 =?us-ascii?Q?5bTaWxngblW2b+7LORmfHi5Qmlks1zW2yHQwc7Ug5c4qms6fVRcda2vHrIXt?=
 =?us-ascii?Q?ba5kLxQbS3uEaB2Dhixt9CwvKnfGAskTNRPRr7F8t531lKWcI7en0U+pPgVC?=
 =?us-ascii?Q?WFT0ygP1RDzcQ2lbmg2Ee/yWel2Dd4hsLE9Vhy/XdSerixrCLob84ejjYv+M?=
 =?us-ascii?Q?oHP2W0XEYG+HMx4+/EFSDu/0LGMGwgPzz6oD6iBA8Dy4QLdypFTzJvgRogE/?=
 =?us-ascii?Q?t7pA1XHeiLKlXb8qTTLfM8Q94J8IlSQg2XVVKlaJa67DlEc7Y5eitaNZ+frV?=
 =?us-ascii?Q?ofIClG0rr/TnK4UFXkrgDubbYK4B+VvQSflDBvcU6tOUgizdnNmwy0UfQOrS?=
 =?us-ascii?Q?FH1kzPnrivuAzTORfMFOc9O/JTtzbRnL3dHabWa2PtKAJtHSAnGwSCj7UiJM?=
 =?us-ascii?Q?umnuLXvbQb0s0bW/ttILjmYHbDwjZ4Mor42q+gSAkXHitcdOMUtup/5wTcQG?=
 =?us-ascii?Q?ESyehpP36m27RhstqcdwZqcXVsEOWMgaqWyCw00zxdb0PPAK06QRWwJ8r5jY?=
 =?us-ascii?Q?upm5PJga8QJtgQSfWegZa+o4eSqKTG+Ef9J7MLKc64tsT50r1UtSzZHMwEnu?=
 =?us-ascii?Q?vqvYiUpRUQoUZcImCqMu5+VWr5sYbk5CC0NDnxBc/TF4GfuXdpypAjrWvXVl?=
 =?us-ascii?Q?AvxTkKzvGr4e28o78MH7qlCi2mHRS3GES73FXQgnVl+8bwLF8sXkCr92weYP?=
 =?us-ascii?Q?owdQMo4VIWISrqdX/v5hmU3ZRr5oVNQac19W9XwF+5sb+0nibW+BGsKtcOn4?=
 =?us-ascii?Q?BAjHqqyfu7uQiHs9MyEwH8PmsxcJ8xAcs4uD4OARPSp4Qy4NoeKBsYkIjW5E?=
 =?us-ascii?Q?wDjQopvvhD3BaXui/2/aMU9aKlgOdAQLGSXH7LW+x+3kmugRZdjKOU8s6yXY?=
 =?us-ascii?Q?pWdM4GX6WWaBuFXk5cXN9Ihcj5HhgHooD7fbjivVwa4CFIqPpVDhZ+zslEic?=
 =?us-ascii?Q?CLSPvu50uR1h5vRzjfEW8icrZGRdXf7IWVn7U2rMFTY/XRb+hGxHzlwKG5Lp?=
 =?us-ascii?Q?9OZMbaNTrrCoaRpNplUeJyYBn1385+FyHfFRCa8R1Qa2GyJpXA5nPNO1c1hB?=
 =?us-ascii?Q?iEFdis5F2bT7MdmlSFB/GZJRPtiUU8GJ3FFv2PfxnoFHnJZZ2ygX6Axpa22A?=
 =?us-ascii?Q?1kb0m2EiXJgS4JWYj0IUwKt4NXadVID+V0zX38GfB9f6Gk9iq8QWYIJ4peGo?=
 =?us-ascii?Q?gYTEl/orkY5eqp9RdwQn5/R8k513oB9D+vMB/4qFL1ATRNygMZCk7VTxs3Hg?=
 =?us-ascii?Q?iO4xPrilTZm/ng6H0UsIbikYHMz9WbHOoV0RxctU1g4NWel22CrllTCDhMuQ?=
 =?us-ascii?Q?fcsKA4lOK3NbvRtYL4e0dRVsGMUs3zj2Ica1sxj+4MyhNCDHxyuZi+85rSlD?=
 =?us-ascii?Q?Ccn0WGjiuhfnJpeySnv9frsP6J87VcWmcFxblhPf0lbp7kd4oK0zCU5zZfCT?=
 =?us-ascii?Q?/XYAEQOr7Lv/7iqfwk1xzz1boxQ6mtn5BVKgZYODWL5wrvb17SEsA3NyTtZJ?=
 =?us-ascii?Q?l0Wx+nfcHlZmKYprE0wu9stlDECTZdwSGkS4ep2w?=
X-MS-Exchange-CrossTenant-Network-Message-Id: 1efa25bb-c372-4a2b-8230-08dbfd0aa147
X-MS-Exchange-CrossTenant-AuthSource: SN6PR11MB3006.namprd11.prod.outlook.com
X-MS-Exchange-CrossTenant-AuthAs: Internal
X-MS-Exchange-CrossTenant-OriginalArrivalTime: 15 Dec 2023 01:10:30.3223
 (UTC)
X-MS-Exchange-CrossTenant-FromEntityHeader: Hosted
X-MS-Exchange-CrossTenant-Id: 46c98d88-e344-4ed4-8496-4ed7712e255d
X-MS-Exchange-CrossTenant-MailboxType: HOSTED
X-MS-Exchange-CrossTenant-UserPrincipalName: WYc6EufxFFk8I2laln6E87QUbo9676njXOZeY4IdW32L6PdijXVw+FYmaWG+SW5XPPVxAY0wHCXB9Uhzc8Fl5Q==
X-MS-Exchange-Transport-CrossTenantHeadersStamped: DM4PR11MB5343
X-OriginatorOrg: intel.com

On Thu, Dec 14, 2023 at 01:50:05PM -0800, Kees Cook wrote:
> On Fri, Dec 15, 2023 at 04:53:19AM +0800, kernel test robot wrote:
> > tree:   https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git master
> > head:   5bd7ef53ffe5ca580e93e74eb8c81ed191ddc4bd
> > commit: fbd126f5a658b92c7f6af986a6d89cf5e5693268 gcov: annotate struct gcov_iterator with __counted_by
> > date:   8 weeks ago
> > config: i386-buildonly-randconfig-001-20231214 (https://download.01.org/0day-ci/archive/20231215/202312150432.oBngC94A-lkp@intel.com/config)
> > compiler: gcc-11 (Debian 11.3.0-12) 11.3.0
> > reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20231215/202312150432.oBngC94A-lkp@intel.com/reproduce)
> > 
> > If you fix the issue in a separate patch/commit (i.e. not just a new version of
> > the same patch/commit), kindly add following tags
> > | Reported-by: kernel test robot <lkp@intel.com>
> > | Closes: https://lore.kernel.org/oe-kbuild-all/202312150432.oBngC94A-lkp@intel.com/
> > 
> > All warnings (new ones prefixed by >>):
> > 
> > >> kernel/gcov/fs.c:103: warning: Excess struct member 'buffer' description in 'gcov_iterator'
> > 
> > 
> > vim +103 kernel/gcov/fs.c
> > 
> > 7a1d55b987dfcb Johannes Berg 2021-05-06   90  
> > 7a1d55b987dfcb Johannes Berg 2021-05-06   91  /**
> > 7a1d55b987dfcb Johannes Berg 2021-05-06   92   * struct gcov_iterator - specifies current file position in logical records
> > 7a1d55b987dfcb Johannes Berg 2021-05-06   93   * @info: associated profiling data
> > 7a1d55b987dfcb Johannes Berg 2021-05-06   94   * @buffer: buffer containing file data
> > 7a1d55b987dfcb Johannes Berg 2021-05-06   95   * @size: size of buffer
> > 7a1d55b987dfcb Johannes Berg 2021-05-06   96   * @pos: current position in file
> > 7a1d55b987dfcb Johannes Berg 2021-05-06   97   */
> > 7a1d55b987dfcb Johannes Berg 2021-05-06   98  struct gcov_iterator {
> > 7a1d55b987dfcb Johannes Berg 2021-05-06   99  	struct gcov_info *info;
> > 7a1d55b987dfcb Johannes Berg 2021-05-06  100  	size_t size;
> > 7a1d55b987dfcb Johannes Berg 2021-05-06  101  	loff_t pos;
> > fbd126f5a658b9 Kees Cook     2023-09-22  102  	char buffer[] __counted_by(size);
> > 7a1d55b987dfcb Johannes Berg 2021-05-06 @103  };
> > 7a1d55b987dfcb Johannes Berg 2021-05-06  104  
> 
> It looks like whatever produces that error is not parsing attributes
> correctly. I suspect this is the "htmldocs" target and "__counted_by" is
> missing from Documentation/conf.py. I'll investigate...

This is triggered by W=1 build

        make W=1 O=build_dir ARCH=i386 olddefconfig
        make W=1 O=build_dir ARCH=i386 SHELL=/bin/bash kernel/gcov/

The detail step is at [1], hope it can help reproduce the issue

[1] https://download.01.org/0day-ci/archive/20231215/202312150432.oBngC94A-lkp@intel.com/reproduce

> 
> -- 
> Kees Cook
>