| Message ID | 20221121024418.1800-3-thunder.leizhen@huawei.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | fs: clear a UBSAN shift-out-of-bounds warning | expand |
On Mon, Nov 21, 2022 at 10:44:18AM +0800, Zhen Lei wrote: > 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); > -- Reviewed-by: Eric Biggers <ebiggers@google.com> - Eric
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);
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(-)