[tegra:for-5.9/firmware 4/5] include/linux/string.h:296:30: warning: '__builtin_strncat' output truncated before terminating nul copying as many bytes from a string as its length
7:28 a.m.
tree: https://git.kernel.org/pub/scm/linux/kernel/git/tegra/linux.git for-5.9/firmware
head: 4e87189912bd2167998d82c95bb68f73185069e2
commit: 5e37b9c137ee5a3a9dc2815ca51f71746c2609a6 [4/5] firmware: tegra: Add support for
in-band debug
config: arm-allyesconfig (attached as .config)
compiler: arm-linux-gnueabi-gcc (GCC) 9.3.0
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
git checkout 5e37b9c137ee5a3a9dc2815ca51f71746c2609a6
# save the attached .config to linux build tree
COMPILER_INSTALL_PATH=$HOME/0day COMPILER=gcc-9.3.0 make.cross ARCH=arm
If you fix the issue, kindly add following tag as appropriate
Reported-by: kernel test robot <lkp(a)intel.com>
All warnings (new ones prefixed by >>):
In file included from include/linux/bitmap.h:9,
from include/linux/cpumask.h:12,
from include/linux/rcupdate.h:31,
from include/linux/rculist.h:11,
from include/linux/dcache.h:7,
from include/linux/fs.h:8,
from include/linux/debugfs.h:15,
from drivers/firmware/tegra/bpmp-debugfs.c:5:
In function 'strncat',
inlined from 'bpmp_populate_debugfs_inband' at
drivers/firmware/tegra/bpmp-debugfs.c:422:4:
> include/linux/string.h:296:30: warning:
'__builtin_strncat' output truncated before terminating nul copying as many bytes
from a string as its length [-Wstringop-truncation]
296 | #define
__underlying_strncat __builtin_strncat
| ^
include/linux/string.h:374:10: note: in expansion of macro
'__underlying_strncat'
374 | return __underlying_strncat(p, q, count);
| ^~~~~~~~~~~~~~~~~~~~
drivers/firmware/tegra/bpmp-debugfs.c: In function
'bpmp_populate_debugfs_inband':
include/linux/string.h:295:29: note: length computed here
295 | #define __underlying_strlen __builtin_strlen
| ^
include/linux/string.h:328:10: note: in expansion of macro
'__underlying_strlen'
328 | return __underlying_strlen(p);
| ^~~~~~~~~~~~~~~~~~~
vim +/__builtin_strncat +296 include/linux/string.h
47227d27e2fcb0 Daniel Axtens 2020-06-03 275
47227d27e2fcb0 Daniel Axtens 2020-06-03 276 #ifdef CONFIG_KASAN
47227d27e2fcb0 Daniel Axtens 2020-06-03 277 extern void *__underlying_memchr(const void
*p, int c, __kernel_size_t size) __RENAME(memchr);
47227d27e2fcb0 Daniel Axtens 2020-06-03 278 extern int __underlying_memcmp(const void
*p, const void *q, __kernel_size_t size) __RENAME(memcmp);
47227d27e2fcb0 Daniel Axtens 2020-06-03 279 extern void *__underlying_memcpy(void *p,
const void *q, __kernel_size_t size) __RENAME(memcpy);
47227d27e2fcb0 Daniel Axtens 2020-06-03 280 extern void *__underlying_memmove(void *p,
const void *q, __kernel_size_t size) __RENAME(memmove);
47227d27e2fcb0 Daniel Axtens 2020-06-03 281 extern void *__underlying_memset(void *p,
int c, __kernel_size_t size) __RENAME(memset);
47227d27e2fcb0 Daniel Axtens 2020-06-03 282 extern char *__underlying_strcat(char *p,
const char *q) __RENAME(strcat);
47227d27e2fcb0 Daniel Axtens 2020-06-03 283 extern char *__underlying_strcpy(char *p,
const char *q) __RENAME(strcpy);
47227d27e2fcb0 Daniel Axtens 2020-06-03 284 extern __kernel_size_t
__underlying_strlen(const char *p) __RENAME(strlen);
47227d27e2fcb0 Daniel Axtens 2020-06-03 285 extern char *__underlying_strncat(char *p,
const char *q, __kernel_size_t count) __RENAME(strncat);
47227d27e2fcb0 Daniel Axtens 2020-06-03 286 extern char *__underlying_strncpy(char *p,
const char *q, __kernel_size_t size) __RENAME(strncpy);
47227d27e2fcb0 Daniel Axtens 2020-06-03 287 #else
47227d27e2fcb0 Daniel Axtens 2020-06-03 288 #define
__underlying_memchr __builtin_memchr
47227d27e2fcb0 Daniel Axtens 2020-06-03 289 #define
__underlying_memcmp __builtin_memcmp
47227d27e2fcb0 Daniel Axtens 2020-06-03 290 #define
__underlying_memcpy __builtin_memcpy
47227d27e2fcb0 Daniel Axtens 2020-06-03 291 #define
__underlying_memmove __builtin_memmove
47227d27e2fcb0 Daniel Axtens 2020-06-03 292 #define
__underlying_memset __builtin_memset
47227d27e2fcb0 Daniel Axtens 2020-06-03 293 #define
__underlying_strcat __builtin_strcat
47227d27e2fcb0 Daniel Axtens 2020-06-03 294 #define
__underlying_strcpy __builtin_strcpy
47227d27e2fcb0 Daniel Axtens 2020-06-03 295 #define
__underlying_strlen __builtin_strlen
47227d27e2fcb0 Daniel Axtens 2020-06-03 @296 #define
__underlying_strncat __builtin_strncat
47227d27e2fcb0 Daniel Axtens 2020-06-03 297 #define
__underlying_strncpy __builtin_strncpy
47227d27e2fcb0 Daniel Axtens 2020-06-03 298 #endif
47227d27e2fcb0 Daniel Axtens 2020-06-03 299
:::::: The code at line 296 was first introduced by commit
:::::: 47227d27e2fcb01a9e8f5958d8997cf47a820afc string.h: fix incompatibility between
FORTIFY_SOURCE and KASAN
:::::: TO: Daniel Axtens <dja(a)axtens.net>
:::::: CC: Linus Torvalds <torvalds(a)linux-foundation.org>
---
0-DAY CI Kernel Test Service, Intel Corporation
https://lists.01.org/hyperkitty/list/kbuild-all@lists.01.org
6:29 p.m.
On 14/07/2020 22:28, kernel test robot wrote:
tree:
https://git.kernel.org/pub/scm/linux/kernel/git/tegra/linux.git for-5.9/firmware
head: 4e87189912bd2167998d82c95bb68f73185069e2
commit: 5e37b9c137ee5a3a9dc2815ca51f71746c2609a6 [4/5] firmware: tegra: Add support for
in-band debug
config: arm-allyesconfig (attached as .config)
compiler: arm-linux-gnueabi-gcc (GCC) 9.3.0
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
git checkout 5e37b9c137ee5a3a9dc2815ca51f71746c2609a6
# save the attached .config to linux build tree
COMPILER_INSTALL_PATH=$HOME/0day COMPILER=gcc-9.3.0 make.cross ARCH=arm
If you fix the issue, kindly add following tag as appropriate
Reported-by: kernel test robot <lkp(a)intel.com>
All warnings (new ones prefixed by >>):
In file included from include/linux/bitmap.h:9,
from include/linux/cpumask.h:12,
from include/linux/rcupdate.h:31,
from include/linux/rculist.h:11,
from include/linux/dcache.h:7,
from include/linux/fs.h:8,
from include/linux/debugfs.h:15,
from drivers/firmware/tegra/bpmp-debugfs.c:5:
In function 'strncat',
inlined from 'bpmp_populate_debugfs_inband' at
drivers/firmware/tegra/bpmp-debugfs.c:422:4:
>> include/linux/string.h:296:30: warning: '__builtin_strncat' output
truncated before terminating nul copying as many bytes from a string as its length
[-Wstringop-truncation]
I took a look at this and see what the above is warning about and if
this is something we need to address.
When I implemented the above, I did take care to ensure that we would
not overflow the buffer and ensure that the string is null terminated.
If you look at the code, following the call to strncat, there is a
subsequent call to strcat which will add the null character. Before any
of these calls are made, the code does check to ensure that the strings
written to the buffer can fit and there is room for the null character.
We could update this code to address the above warning, but at the same
time I don't believe it is necessary.
Cheers
Jon
--
nvpublic
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Jon Hunter -
kernel test robot