Messages in this thread Patch in this message |  | | From | Zhen Lei <> | Subject | [PATCH v2 2/2] fs: clear a UBSAN shift-out-of-bounds warning | Date | Mon, 21 Nov 2022 10:44:18 +0800 |
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UBSAN: shift-out-of-bounds in fs/locks.c:2572:16 left shift of 1 by 63 places cannot be represented in type 'long long int'
Switch the calculation method to type_max() can help us eliminate this false positive.
On the other hand, the old implementation has problems with char and short types, although not currently involved. printf("%d: %x\n", sizeof(char), INT_LIMIT(char)); printf("%d: %x\n", sizeof(short), INT_LIMIT(short)); 1: ffffff7f 2: ffff7fff
Suggested-by: Eric Biggers <ebiggers@kernel.org> Signed-off-by: Zhen Lei <thunder.leizhen@huawei.com> --- include/linux/fs.h | 5 ++--- 1 file changed, 2 insertions(+), 3 deletions(-)
diff --git a/include/linux/fs.h b/include/linux/fs.h index e654435f16512c1..a384741b1449457 100644 --- a/include/linux/fs.h +++ b/include/linux/fs.h @@ -1131,9 +1131,8 @@ struct file_lock_context { /* The following constant reflects the upper bound of the file/locking space */ #ifndef OFFSET_MAX -#define INT_LIMIT(x) (~((x)1 << (sizeof(x)*8 - 1))) -#define OFFSET_MAX INT_LIMIT(loff_t) -#define OFFT_OFFSET_MAX INT_LIMIT(off_t) +#define OFFSET_MAX type_max(loff_t) +#define OFFT_OFFSET_MAX type_max(off_t) #endif extern void send_sigio(struct fown_struct *fown, int fd, int band); -- 2.25.1
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