include/linux/kasan-checks.h:38:27: warning: 'transid' may be used uninitialized
From: kernel test robot
Date: Wed Apr 26 2023 - 19:44:04 EST
Hi Josef,
FYI, the error/warning still remains.
tree: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git master
head: 36006b1d5c04692924f011aa949e8788f1c604de
commit: 1ec49744ba83f0429c5c706708610f7821a7b6f4 btrfs: turn on -Wmaybe-uninitialized
date: 2 months ago
config: arm-randconfig-r046-20230427 (https://download.01.org/0day-ci/archive/20230427/202304270743.t9Wk3Dsu-lkp@xxxxxxxxx/config)
compiler: arm-linux-gnueabi-gcc (GCC) 12.1.0
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=1ec49744ba83f0429c5c706708610f7821a7b6f4
git remote add linus https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
git fetch --no-tags linus master
git checkout 1ec49744ba83f0429c5c706708610f7821a7b6f4
# save the config file
mkdir build_dir && cp config build_dir/.config
COMPILER_INSTALL_PATH=$HOME/0day COMPILER=gcc-12.1.0 make.cross W=1 O=build_dir ARCH=arm olddefconfig
COMPILER_INSTALL_PATH=$HOME/0day COMPILER=gcc-12.1.0 make.cross W=1 O=build_dir ARCH=arm SHELL=/bin/bash fs/btrfs/
If you fix the issue, kindly add following tag where applicable
| Reported-by: kernel test robot <lkp@xxxxxxxxx>
| Link: https://lore.kernel.org/oe-kbuild-all/202304270743.t9Wk3Dsu-lkp@xxxxxxxxx/
Note: it may well be a FALSE warning. FWIW you are at least aware of it now.
http://gcc.gnu.org/wiki/Better_Uninitialized_Warnings
All warnings (new ones prefixed by >>):
In file included from include/asm-generic/rwonce.h:26,
from ./arch/arm/include/generated/asm/rwonce.h:1,
from include/linux/compiler.h:247,
from include/linux/kernel.h:20,
from fs/btrfs/ioctl.c:6:
include/linux/kasan-checks.h: In function 'btrfs_ioctl_wait_sync':
>> include/linux/kasan-checks.h:38:27: warning: 'transid' may be used uninitialized [-Wmaybe-uninitialized]
38 | #define kasan_check_write __kasan_check_write
| ^~~~~~~~~~~~~~~~~~~
include/linux/kasan-checks.h:20:6: note: by argument 1 of type 'const volatile void *' to '__kasan_check_write' declared here
20 | bool __kasan_check_write(const volatile void *p, unsigned int size);
| ^~~~~~~~~~~~~~~~~~~
fs/btrfs/ioctl.c:3134:13: note: 'transid' declared here
3134 | u64 transid;
| ^~~~~~~
include/linux/kasan-checks.h: In function 'btrfs_ioctl_space_info':
>> include/linux/kasan-checks.h:38:27: warning: 'space_args' may be used uninitialized [-Wmaybe-uninitialized]
38 | #define kasan_check_write __kasan_check_write
| ^~~~~~~~~~~~~~~~~~~
include/linux/kasan-checks.h:20:6: note: by argument 1 of type 'const volatile void *' to '__kasan_check_write' declared here
20 | bool __kasan_check_write(const volatile void *p, unsigned int size);
| ^~~~~~~~~~~~~~~~~~~
fs/btrfs/ioctl.c:2973:39: note: 'space_args' declared here
2973 | struct btrfs_ioctl_space_args space_args;
| ^~~~~~~~~~
vim +/transid +38 include/linux/kasan-checks.h
b5f6e0fc7d60e0 Marco Elver 2019-07-11 6
611806b4bf8dd9 Andrey Konovalov 2021-02-24 7 /*
611806b4bf8dd9 Andrey Konovalov 2021-02-24 8 * The annotations present in this file are only relevant for the software
611806b4bf8dd9 Andrey Konovalov 2021-02-24 9 * KASAN modes that rely on compiler instrumentation, and will be optimized
611806b4bf8dd9 Andrey Konovalov 2021-02-24 10 * away for the hardware tag-based KASAN mode. Use kasan_check_byte() instead.
611806b4bf8dd9 Andrey Konovalov 2021-02-24 11 */
611806b4bf8dd9 Andrey Konovalov 2021-02-24 12
7d8ad890dad00f Marco Elver 2019-07-11 13 /*
7d8ad890dad00f Marco Elver 2019-07-11 14 * __kasan_check_*: Always available when KASAN is enabled. This may be used
7d8ad890dad00f Marco Elver 2019-07-11 15 * even in compilation units that selectively disable KASAN, but must use KASAN
7d8ad890dad00f Marco Elver 2019-07-11 16 * to validate access to an address. Never use these in header files!
7d8ad890dad00f Marco Elver 2019-07-11 17 */
0fea6e9af889f1 Andrey Konovalov 2020-12-22 18 #if defined(CONFIG_KASAN_GENERIC) || defined(CONFIG_KASAN_SW_TAGS)
b5f6e0fc7d60e0 Marco Elver 2019-07-11 19 bool __kasan_check_read(const volatile void *p, unsigned int size);
b5f6e0fc7d60e0 Marco Elver 2019-07-11 @20 bool __kasan_check_write(const volatile void *p, unsigned int size);
7d8ad890dad00f Marco Elver 2019-07-11 21 #else
b5f6e0fc7d60e0 Marco Elver 2019-07-11 22 static inline bool __kasan_check_read(const volatile void *p, unsigned int size)
b5f6e0fc7d60e0 Marco Elver 2019-07-11 23 {
b5f6e0fc7d60e0 Marco Elver 2019-07-11 24 return true;
b5f6e0fc7d60e0 Marco Elver 2019-07-11 25 }
b5f6e0fc7d60e0 Marco Elver 2019-07-11 26 static inline bool __kasan_check_write(const volatile void *p, unsigned int size)
b5f6e0fc7d60e0 Marco Elver 2019-07-11 27 {
b5f6e0fc7d60e0 Marco Elver 2019-07-11 28 return true;
b5f6e0fc7d60e0 Marco Elver 2019-07-11 29 }
7d8ad890dad00f Marco Elver 2019-07-11 30 #endif
7d8ad890dad00f Marco Elver 2019-07-11 31
7d8ad890dad00f Marco Elver 2019-07-11 32 /*
7d8ad890dad00f Marco Elver 2019-07-11 33 * kasan_check_*: Only available when the particular compilation unit has KASAN
7d8ad890dad00f Marco Elver 2019-07-11 34 * instrumentation enabled. May be used in header files.
7d8ad890dad00f Marco Elver 2019-07-11 35 */
7d8ad890dad00f Marco Elver 2019-07-11 36 #ifdef __SANITIZE_ADDRESS__
7d8ad890dad00f Marco Elver 2019-07-11 37 #define kasan_check_read __kasan_check_read
7d8ad890dad00f Marco Elver 2019-07-11 @38 #define kasan_check_write __kasan_check_write
64f8ebaf115bcd Andrey Ryabinin 2016-05-20 39 #else
b5f6e0fc7d60e0 Marco Elver 2019-07-11 40 static inline bool kasan_check_read(const volatile void *p, unsigned int size)
b5f6e0fc7d60e0 Marco Elver 2019-07-11 41 {
b5f6e0fc7d60e0 Marco Elver 2019-07-11 42 return true;
b5f6e0fc7d60e0 Marco Elver 2019-07-11 43 }
b5f6e0fc7d60e0 Marco Elver 2019-07-11 44 static inline bool kasan_check_write(const volatile void *p, unsigned int size)
b5f6e0fc7d60e0 Marco Elver 2019-07-11 45 {
b5f6e0fc7d60e0 Marco Elver 2019-07-11 46 return true;
b5f6e0fc7d60e0 Marco Elver 2019-07-11 47 }
64f8ebaf115bcd Andrey Ryabinin 2016-05-20 48 #endif
64f8ebaf115bcd Andrey Ryabinin 2016-05-20 49
:::::: The code at line 38 was first introduced by commit
:::::: 7d8ad890dad00f6cd64bfb44d9be4fceb10cf819 mm/kasan: introduce __kasan_check_{read,write}
:::::: TO: Marco Elver <elver@xxxxxxxxxx>
:::::: CC: Linus Torvalds <torvalds@xxxxxxxxxxxxxxxxxxxx>
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https://github.com/intel/lkp-tests