On Tue 11-06-19 02:22:17, Ajay Kaher wrote:
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@vmware.com
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;
I have missed this part in 4.4 stable backport. Thanks for catching it. I have updated my backport.
@@ -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);