| Message ID | 1561410186-3919-2-git-send-email-akaher@vmware.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | [v4,1/3,v4.9.y] coredump: fix race condition between mmget_not_zero()/get_task_mm() and core dumping | expand |
On Tue, Jun 25, 2019 at 02:33:04AM +0530, 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(-) Looks OK Reviewed-by: Jason Gunthorpe <jgg@mellanox.com> Thanks Jason
diff --git a/drivers/infiniband/hw/mlx4/main.c b/drivers/infiniband/hw/mlx4/main.c index 8d59a59..7ccf722 100644 --- a/drivers/infiniband/hw/mlx4/main.c +++ b/drivers/infiniband/hw/mlx4/main.c @@ -1172,6 +1172,8 @@ 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) @@ -1190,7 +1192,7 @@ 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 b1daf5c..f94df0e 100644 --- a/drivers/infiniband/hw/mlx5/main.c +++ b/drivers/infiniband/hw/mlx5/main.c @@ -1307,6 +1307,8 @@ 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; list_for_each_entry_safe(vma_private, n, &context->vma_private_list, list) { vma = vma_private->vma; @@ -1321,6 +1323,7 @@ static void mlx5_ib_disassociate_ucontext(struct ib_ucontext *ibcontext) list_del(&vma_private->list); kfree(vma_private); } +skip_mm: up_write(&owning_mm->mmap_sem); mmput(owning_mm); put_task_struct(owning_process);
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(-)