block/partitions/ldm.c:134:9: warning: 'strncpy' specified bound 16 equals destination size

From: kernel test robot
Date: Wed Sep 08 2021 - 17:43:24 EST

tree: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git master
head: 2d338201d5311bcd79d42f66df4cecbcbc5f4f2c
commit: 334ef6ed06fa1a54e35296b77b693bcf6d63ee9e init/Kconfig: make COMPILE_TEST depend on !S390
date: 10 months ago
config: s390-buildonly-randconfig-r005-20210909 (attached as .config)
compiler: s390-linux-gcc (GCC) 11.2.0
reproduce (this is a W=1 build):
wget https://raw.githubusercontent.com/intel/lkp-tests/master/sbin/make.cross -O ~/bin/make.cross
chmod +x ~/bin/make.cross
# https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=334ef6ed06fa1a54e35296b77b693bcf6d63ee9e
git remote add linus https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
git fetch --no-tags linus master
git checkout 334ef6ed06fa1a54e35296b77b693bcf6d63ee9e
# save the attached .config to linux build tree
COMPILER_INSTALL_PATH=$HOME/0day COMPILER=gcc-11.2.0 make.cross ARCH=s390

If you fix the issue, kindly add following tag as appropriate
Reported-by: kernel test robot <lkp@xxxxxxxxx>

All warnings (new ones prefixed by >>):

In function 'ldm_parse_tocblock',
inlined from 'ldm_validate_tocblocks' at block/partitions/ldm.c:386:7:
>> block/partitions/ldm.c:134:9: warning: 'strncpy' specified bound 16 equals destination size [-Wstringop-truncation]
134 | strncpy (toc->bitmap1_name, data + 0x24, sizeof (toc->bitmap1_name));
| ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
block/partitions/ldm.c:145:9: warning: 'strncpy' specified bound 16 equals destination size [-Wstringop-truncation]
145 | strncpy (toc->bitmap2_name, data + 0x46, sizeof (toc->bitmap2_name));
| ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~


vim +/strncpy +134 block/partitions/ldm.c

^1da177e4c3f41 fs/partitions/ldm.c Linus Torvalds 2005-04-16 111
^1da177e4c3f41 fs/partitions/ldm.c Linus Torvalds 2005-04-16 112 /**
^1da177e4c3f41 fs/partitions/ldm.c Linus Torvalds 2005-04-16 113 * ldm_parse_tocblock - Read the LDM Database TOCBLOCK structure
^1da177e4c3f41 fs/partitions/ldm.c Linus Torvalds 2005-04-16 114 * @data: Raw database TOCBLOCK structure loaded from the device
^1da177e4c3f41 fs/partitions/ldm.c Linus Torvalds 2005-04-16 115 * @toc: In-memory toc structure in which to return parsed information
^1da177e4c3f41 fs/partitions/ldm.c Linus Torvalds 2005-04-16 116 *
^1da177e4c3f41 fs/partitions/ldm.c Linus Torvalds 2005-04-16 117 * This parses the LDM Database TOCBLOCK (table of contents) structure supplied
^1da177e4c3f41 fs/partitions/ldm.c Linus Torvalds 2005-04-16 118 * in @data and sets up the in-memory tocblock structure @toc with the obtained
^1da177e4c3f41 fs/partitions/ldm.c Linus Torvalds 2005-04-16 119 * information.
^1da177e4c3f41 fs/partitions/ldm.c Linus Torvalds 2005-04-16 120 *
^1da177e4c3f41 fs/partitions/ldm.c Linus Torvalds 2005-04-16 121 * N.B. The *_start and *_size values returned in @toc are not range-checked.
^1da177e4c3f41 fs/partitions/ldm.c Linus Torvalds 2005-04-16 122 *
130c6b98984a05 fs/partitions/ldm.c Richard Knutsson 2006-09-30 123 * Return: 'true' @toc contains the TOCBLOCK data
130c6b98984a05 fs/partitions/ldm.c Richard Knutsson 2006-09-30 124 * 'false' @toc contents are undefined
^1da177e4c3f41 fs/partitions/ldm.c Linus Torvalds 2005-04-16 125 */
130c6b98984a05 fs/partitions/ldm.c Richard Knutsson 2006-09-30 126 static bool ldm_parse_tocblock (const u8 *data, struct tocblock *toc)
^1da177e4c3f41 fs/partitions/ldm.c Linus Torvalds 2005-04-16 127 {
^1da177e4c3f41 fs/partitions/ldm.c Linus Torvalds 2005-04-16 128 BUG_ON (!data || !toc);
^1da177e4c3f41 fs/partitions/ldm.c Linus Torvalds 2005-04-16 129
b7bbf8fa6ba329 fs/partitions/ldm.c Harvey Harrison 2008-07-25 130 if (MAGIC_TOCBLOCK != get_unaligned_be64(data)) {
^1da177e4c3f41 fs/partitions/ldm.c Linus Torvalds 2005-04-16 131 ldm_crit ("Cannot find TOCBLOCK, database may be corrupt.");
130c6b98984a05 fs/partitions/ldm.c Richard Knutsson 2006-09-30 132 return false;
^1da177e4c3f41 fs/partitions/ldm.c Linus Torvalds 2005-04-16 133 }
^1da177e4c3f41 fs/partitions/ldm.c Linus Torvalds 2005-04-16 @134 strncpy (toc->bitmap1_name, data + 0x24, sizeof (toc->bitmap1_name));
^1da177e4c3f41 fs/partitions/ldm.c Linus Torvalds 2005-04-16 135 toc->bitmap1_name[sizeof (toc->bitmap1_name) - 1] = 0;
b7bbf8fa6ba329 fs/partitions/ldm.c Harvey Harrison 2008-07-25 136 toc->bitmap1_start = get_unaligned_be64(data + 0x2E);
b7bbf8fa6ba329 fs/partitions/ldm.c Harvey Harrison 2008-07-25 137 toc->bitmap1_size = get_unaligned_be64(data + 0x36);
^1da177e4c3f41 fs/partitions/ldm.c Linus Torvalds 2005-04-16 138
^1da177e4c3f41 fs/partitions/ldm.c Linus Torvalds 2005-04-16 139 if (strncmp (toc->bitmap1_name, TOC_BITMAP1,
^1da177e4c3f41 fs/partitions/ldm.c Linus Torvalds 2005-04-16 140 sizeof (toc->bitmap1_name)) != 0) {
^1da177e4c3f41 fs/partitions/ldm.c Linus Torvalds 2005-04-16 141 ldm_crit ("TOCBLOCK's first bitmap is '%s', should be '%s'.",
^1da177e4c3f41 fs/partitions/ldm.c Linus Torvalds 2005-04-16 142 TOC_BITMAP1, toc->bitmap1_name);
130c6b98984a05 fs/partitions/ldm.c Richard Knutsson 2006-09-30 143 return false;
^1da177e4c3f41 fs/partitions/ldm.c Linus Torvalds 2005-04-16 144 }
^1da177e4c3f41 fs/partitions/ldm.c Linus Torvalds 2005-04-16 145 strncpy (toc->bitmap2_name, data + 0x46, sizeof (toc->bitmap2_name));
^1da177e4c3f41 fs/partitions/ldm.c Linus Torvalds 2005-04-16 146 toc->bitmap2_name[sizeof (toc->bitmap2_name) - 1] = 0;
b7bbf8fa6ba329 fs/partitions/ldm.c Harvey Harrison 2008-07-25 147 toc->bitmap2_start = get_unaligned_be64(data + 0x50);
b7bbf8fa6ba329 fs/partitions/ldm.c Harvey Harrison 2008-07-25 148 toc->bitmap2_size = get_unaligned_be64(data + 0x58);
^1da177e4c3f41 fs/partitions/ldm.c Linus Torvalds 2005-04-16 149 if (strncmp (toc->bitmap2_name, TOC_BITMAP2,
^1da177e4c3f41 fs/partitions/ldm.c Linus Torvalds 2005-04-16 150 sizeof (toc->bitmap2_name)) != 0) {
^1da177e4c3f41 fs/partitions/ldm.c Linus Torvalds 2005-04-16 151 ldm_crit ("TOCBLOCK's second bitmap is '%s', should be '%s'.",
^1da177e4c3f41 fs/partitions/ldm.c Linus Torvalds 2005-04-16 152 TOC_BITMAP2, toc->bitmap2_name);
130c6b98984a05 fs/partitions/ldm.c Richard Knutsson 2006-09-30 153 return false;
^1da177e4c3f41 fs/partitions/ldm.c Linus Torvalds 2005-04-16 154 }
^1da177e4c3f41 fs/partitions/ldm.c Linus Torvalds 2005-04-16 155 ldm_debug ("Parsed TOCBLOCK successfully.");
130c6b98984a05 fs/partitions/ldm.c Richard Knutsson 2006-09-30 156 return true;
^1da177e4c3f41 fs/partitions/ldm.c Linus Torvalds 2005-04-16 157 }
^1da177e4c3f41 fs/partitions/ldm.c Linus Torvalds 2005-04-16 158

:::::: The code at line 134 was first introduced by commit
:::::: 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 Linux-2.6.12-rc2

:::::: TO: Linus Torvalds <torvalds@xxxxxxxxxxxxxxx>
:::::: CC: Linus Torvalds <torvalds@xxxxxxxxxxxxxxx>

---
0-DAY CI Kernel Test Service, Intel Corporation
https://lists.01.org/hyperkitty/list/kbuild-all@xxxxxxxxxxxx

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