Date: Sat, 18 Nov 2023 23:01:09 +0800
From: kernel test robot <lkp@...el.com>
To: Kees Cook <keescook@...omium.org>, Anders Larsen <al@...rsen.net>
Cc: oe-kbuild-all@...ts.linux.dev, Kees Cook <keescook@...omium.org>,
	Ronald Monthero <debug.penguin32@...il.com>,
	linux-kernel@...r.kernel.org, linux-hardening@...r.kernel.org
Subject: Re: [PATCH 1/2] qnx4: Extract dir entry filename processing into
 helper

Hi Kees,

kernel test robot noticed the following build errors:

[auto build test ERROR on linus/master]
[also build test ERROR on v6.7-rc1 next-20231117]
[If your patch is applied to the wrong git tree, kindly drop us a note.
And when submitting patch, we suggest to use '--base' as documented in
https://git-scm.com/docs/git-format-patch#_base_tree_information]

url:    https://github.com/intel-lab-lkp/linux/commits/Kees-Cook/qnx4-Extract-dir-entry-filename-processing-into-helper/20231118-114223
base:   linus/master
patch link:    https://lore.kernel.org/r/20231118033225.2181299-1-keescook%40chromium.org
patch subject: [PATCH 1/2] qnx4: Extract dir entry filename processing into helper
config: i386-randconfig-011-20231118 (https://download.01.org/0day-ci/archive/20231118/202311182210.gREgIbSb-lkp@intel.com/config)
compiler: gcc-7 (Ubuntu 7.5.0-6ubuntu2) 7.5.0
reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20231118/202311182210.gREgIbSb-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@...el.com>
| Closes: https://lore.kernel.org/oe-kbuild-all/202311182210.gREgIbSb-lkp@intel.com/

All errors (new ones prefixed by >>):

   In file included from fs/qnx4/dir.c:16:0:
>> fs/qnx4/qnx4.h:86:51: error: expected ',' before ')' token
            offsetof(struct qnx4_link_info, dl_status));
                                                      ^
   fs/qnx4/qnx4.h:88:56: error: expected ',' before ')' token
            offsetof(union qnx4_directory_entry, de_status));
                                                           ^


vim +86 fs/qnx4/qnx4.h

    47	
    48	/*
    49	 * A qnx4 directory entry is an inode entry or link info
    50	 * depending on the status field in the last byte. The
    51	 * first byte is where the name start either way, and a
    52	 * zero means it's empty.
    53	 *
    54	 * Also, due to a bug in gcc, we don't want to use the
    55	 * real (differently sized) name arrays in the inode and
    56	 * link entries, but always the 'de_name[]' one in the
    57	 * fake struct entry.
    58	 *
    59	 * See
    60	 *
    61	 *   https://gcc.gnu.org/bugzilla/show_bug.cgi?id=99578#c6
    62	 *
    63	 * for details, but basically gcc will take the size of the
    64	 * 'name' array from one of the used union entries randomly.
    65	 *
    66	 * This use of 'de_name[]' (48 bytes) avoids the false positive
    67	 * warnings that would happen if gcc decides to use 'inode.di_name'
    68	 * (16 bytes) even when the pointer and size were to come from
    69	 * 'link.dl_name' (48 bytes).
    70	 *
    71	 * In all cases the actual name pointer itself is the same, it's
    72	 * only the gcc internal 'what is the size of this field' logic
    73	 * that can get confused.
    74	 */
    75	union qnx4_directory_entry {
    76		struct {
    77			const char de_name[48];
    78			u8 de_pad[15];
    79			u8 de_status;
    80		};
    81		struct qnx4_inode_entry inode;
    82		struct qnx4_link_info link;
    83	};
    84	/* Make sure the status byte is in the same place for all structs. */
    85	_Static_assert(offsetof(struct qnx4_inode_entry, di_status) ==
  > 86		       offsetof(struct qnx4_link_info, dl_status));
    87	_Static_assert(offsetof(struct qnx4_inode_entry, di_status) ==
    88		       offsetof(union qnx4_directory_entry, de_status));
    89	

-- 
0-DAY CI Kernel Test Service
https://github.com/intel/lkp-tests/wiki

Powered by blists - more mailing lists