[ Upstream commit
b79f2dc5ffe17b03ec8c55f0d63f65e87bcac676 ]
rounddown_pow_of_two() is undefined when the input is 0. Therefore we need
to avoid it in ib_umem_find_best_pgsz and return 0. Otherwise, it could
result in not rejecting an invalid page size which eventually causes a
kernel oops due to the logical inconsistency.
Fixes:
3361c29e9279 ("RDMA/umem: Use simpler logic for ib_umem_find_best_pgsz()")
Link: https://lore.kernel.org/r/20210113121703.559778-2-leon@kernel.org
Signed-off-by: Aharon Landau <aharonl@nvidia.com>
Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
Reviewed-by: Maor Gottlieb <maorg@mellanox.com>
Signed-off-by: Leon Romanovsky <leonro@nvidia.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
*/
if (mask)
pgsz_bitmap &= GENMASK(count_trailing_zeros(mask), 0);
- return rounddown_pow_of_two(pgsz_bitmap);
+ return pgsz_bitmap ? rounddown_pow_of_two(pgsz_bitmap) : 0;
}
EXPORT_SYMBOL(ib_umem_find_best_pgsz);