This patch is the extension of following upstream commit to fix
the race condition between get_task_mm() and core dumping
for IB->mlx4 and IB->mlx5 drivers:
commit 04f5866e41fb ("coredump: fix race condition between
mmget_not_zero()/get_task_mm() and core dumping")'
Thanks to Jason for pointing this.
Signed-off-by: Ajay Kaher <akaher@xxxxxxxxxx>
---
drivers/infiniband/hw/mlx4/main.c | 4 +++-
drivers/infiniband/hw/mlx5/main.c | 3 +++
2 files changed, 6 insertions(+), 1 deletion(-)
diff --git a/drivers/infiniband/hw/mlx4/main.c b/drivers/infiniband/hw/mlx4/main.c
index e2beb18..0299c06 100644
--- a/drivers/infiniband/hw/mlx4/main.c
+++ b/drivers/infiniband/hw/mlx4/main.c
@@ -1197,6 +1197,8 @@ 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)
@@ -1215,7 +1217,7 @@ static void mlx4_ib_disassociate_ucontext(struct ib_ucontext *ibcontext)
/* context going to be destroyed, should not access ops any more */
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);
diff --git a/drivers/infiniband/hw/mlx5/main.c b/drivers/infiniband/hw/mlx5/main.c
index 13a9206..3fbe396 100644
--- a/drivers/infiniband/hw/mlx5/main.c
+++ b/drivers/infiniband/hw/mlx5/main.c
@@ -1646,6 +1646,8 @@ static void mlx5_ib_disassociate_ucontext(struct ib_ucontext *ibcontext)
* mlx5_ib_vma_close.
*/
down_write(&owning_mm->mmap_sem);
+ if (!mmget_still_valid(owning_mm))
+ goto skip_mm;
mutex_lock(&context->vma_private_list_mutex);
list_for_each_entry_safe(vma_private, n, &context->vma_private_list,
list) {
@@ -1662,6 +1664,7 @@ static void mlx5_ib_disassociate_ucontext(struct ib_ucontext *ibcontext)
kfree(vma_private);
}
mutex_unlock(&context->vma_private_list_mutex);
+skip_mm:
up_write(&owning_mm->mmap_sem);
mmput(owning_mm);
put_task_struct(owning_process);
--
2.7.4
