From: Leon Romanovsky <leon@kernel.org>
To: Doug Ledford <dledford@redhat.com>, Jason Gunthorpe <jgg@nvidia.com>
Cc: Aharon Landau <aharonl@nvidia.com>,
linux-rdma@vger.kernel.org, Maor Gottlieb <maorg@mellanox.com>,
Mark Bloch <mbloch@nvidia.com>, Parav Pandit <parav@nvidia.com>
Subject: [PATCH rdma-next 1/5] RDMA/umem: Avoid undefined behavior of rounddown_pow_of_two
Date: Wed, 13 Jan 2021 14:16:59 +0200 [thread overview]
Message-ID: <20210113121703.559778-2-leon@kernel.org> (raw)
In-Reply-To: <20210113121703.559778-1-leon@kernel.org>
From: Aharon Landau <aharonl@nvidia.com>
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 incorrect page size.
Fixes: 3361c29e9279 ("RDMA/umem: Use simpler logic for ib_umem_find_best_pgsz()")
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>
---
drivers/infiniband/core/umem.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/drivers/infiniband/core/umem.c b/drivers/infiniband/core/umem.c
index 95be8cc75d2e..baaf1bf22941 100644
--- a/drivers/infiniband/core/umem.c
+++ b/drivers/infiniband/core/umem.c
@@ -137,7 +137,7 @@ unsigned long ib_umem_find_best_pgsz(struct ib_umem *umem,
*/
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);
--
2.29.2
next prev parent reply other threads:[~2021-01-13 12:18 UTC|newest]
Thread overview: 9+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-01-13 12:16 [PATCH rdma-next 0/5] Set of fixes Leon Romanovsky
2021-01-13 12:16 ` Leon Romanovsky [this message]
2021-01-13 12:17 ` [PATCH rdma-next 2/5] IB/mlx5: Fix error unwinding when set_has_smi_cap fails Leon Romanovsky
2021-01-13 12:17 ` [PATCH rdma-next 3/5] IB/mlx5: Add mutex destroy call to cap_mask_mutex mutex Leon Romanovsky
2021-01-13 12:17 ` [PATCH rdma-next 4/5] IB/mlx5: Make function static Leon Romanovsky
2021-01-13 12:17 ` [PATCH rdma-next 5/5] RDMA/mlx5: Fix wrong free of blue flame register on error Leon Romanovsky
2021-01-14 17:04 ` [PATCH rdma-next 0/5] Set of fixes Jason Gunthorpe
2021-01-14 17:36 ` Leon Romanovsky
2021-01-20 0:15 ` Jason Gunthorpe
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