Just a heads up. Ajay Kaher has noticed that mlx4 driver is missing the
check in 4.14 [1] and 4.4 seems to have the same problem. I will wait
for more review before reposting v3. The incremental diff is:
diff --git a/drivers/infiniband/hw/mlx4/main.c
b/drivers/infiniband/hw/mlx4/main.c
index 67c4c73343d4..6968154a073e 100644
--- a/drivers/infiniband/hw/mlx4/main.c
+++ b/drivers/infiniband/hw/mlx4/main.c
@@ -1042,6 +1042,8 @@ static void mlx4_ib_disassociate_ucontext(struct
ib_ucontext *ibcontext)
* mlx4_ib_vma_close().
*/
down_write(&owning_mm->mmap_sem);
+ if (!mmget_still_valid(owning_mm))
+ goto skip_mm;
for (i = 0; i < HW_BAR_COUNT; i++) {
vma = context->hw_bar_info[i].vma;
if (!vma)
@@ -1061,6 +1063,7 @@ static void mlx4_ib_disassociate_ucontext(struct
ib_ucontext *ibcontext)
context->hw_bar_info[i].vma->vm_ops = NULL;
}
+skip_mm:
up_write(&owning_mm->mmap_sem);
mmput(owning_mm);
put_task_struct(owning_process);
--
Michal Hocko
SUSE Labs
