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| author | Maor Gottlieb <maorg@mellanox.com> | 2017-03-29 06:03:02 +0300 |
|---|---|---|
| committer | Doug Ledford <dledford@redhat.com> | 2017-04-21 12:26:05 -0400 |
| commit | ecc7d83be3243835c9396a1a2fb8ce95f205207b (patch) | |
| tree | 974b9d74fec90fb7532383312f2b5330a353e363 | |
| parent | ca37a664a8e4e9988b220988ceb4d79e3316f195 (diff) | |
| download | linux-ecc7d83be3243835c9396a1a2fb8ce95f205207b.tar.gz linux-ecc7d83be3243835c9396a1a2fb8ce95f205207b.tar.bz2 linux-ecc7d83be3243835c9396a1a2fb8ce95f205207b.zip | |
IB/mlx5: Take write semaphore when changing the vma struct
When the driver disassociate user context, it changes the vma to
anonymous by setting the vm_ops to null and zap the vma ptes.
In order to avoid race in the kernel, we need to take write lock
before we change the vma entries.
Fixes: 7c2344c3bbf97 ('IB/mlx5: Implements disassociate_ucontext API')
Signed-off-by: Maor Gottlieb <maorg@mellanox.com>
Signed-off-by: Leon Romanovsky <leon@kernel.org>
Signed-off-by: Doug Ledford <dledford@redhat.com>
| -rw-r--r-- | drivers/infiniband/hw/mlx5/main.c | 4 |
1 files changed, 2 insertions, 2 deletions
diff --git a/drivers/infiniband/hw/mlx5/main.c b/drivers/infiniband/hw/mlx5/main.c index 4dc0a8785fe0..88070a7cde48 100644 --- a/drivers/infiniband/hw/mlx5/main.c +++ b/drivers/infiniband/hw/mlx5/main.c @@ -1478,7 +1478,7 @@ static void mlx5_ib_disassociate_ucontext(struct ib_ucontext *ibcontext) /* need to protect from a race on closing the vma as part of * mlx5_ib_vma_close. */ - down_read(&owning_mm->mmap_sem); + down_write(&owning_mm->mmap_sem); list_for_each_entry_safe(vma_private, n, &context->vma_private_list, list) { vma = vma_private->vma; @@ -1492,7 +1492,7 @@ static void mlx5_ib_disassociate_ucontext(struct ib_ucontext *ibcontext) list_del(&vma_private->list); kfree(vma_private); } - up_read(&owning_mm->mmap_sem); + up_write(&owning_mm->mmap_sem); mmput(owning_mm); put_task_struct(owning_process); } |