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0d214d14be
[COMPILER WARNING]
With GCC 11.5.0 and KASAN enabled on ARM, the following warning is
triggered during compiling:
In file included from ./include/asm-generic/rwonce.h:26,
from ./arch/arm64/include/asm/rwonce.h:81,
from ./include/linux/compiler.h:369,
from ./include/linux/array_size.h:5,
from ./include/linux/kernel.h:16,
from fs/btrfs/ioctl.c:6:
In function ‘instrument_copy_from_user_before’,
inlined from ‘_inline_copy_from_user’ at ./include/linux/uaccess.h:184:2,
inlined from ‘copy_from_user’ at ./include/linux/uaccess.h:222:9,
inlined from ‘btrfs_ioctl_get_csums.isra’ at fs/btrfs/ioctl.c:5220:6:
./include/linux/kasan-checks.h:38:27: warning: ‘args’ may be used uninitialized [-Wmaybe-uninitialized]
38 | #define kasan_check_write __kasan_check_write
./include/linux/instrumented.h:146:9: note: in expansion of macro ‘kasan_check_write’
146 | kasan_check_write(to, n);
| ^~~~~~~~~~~~~~~~~
fs/btrfs/ioctl.c: In function ‘btrfs_ioctl_get_csums.isra’:
./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:5201:43: note: ‘args’ declared here
5201 | struct btrfs_ioctl_get_csums_args args;
| ^~~~
[POSSIBLE FALSE ALERTS]
This seems to be a false alert from certain GCC versions.
The @args is immediately over-written by copy_from_user(), and there is
no code touching that @args until copy_from_user() finished correctly.
[WORKAROUND]
Initialize 'args' to zero, which suppresses the warning.
Reviewed-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
5670 lines
142 KiB
5670 lines
142 KiB