Re: WARNING in af_alg_make_sg

[Michal Hocko]

On Wed 08-04-20 11:12:13, Peter Xu wrote:
> >From 380003a56efc125565143c91ee6cefd7b3eba869 Mon Sep 17 00:00:00 2001
> From: Hillf Danton <hdanton@xxxxxxxx>
> Date: Wed, 8 Apr 2020 11:01:25 -0400
> Subject: [PATCH] mm/gup: Let __get_user_pages_locked() return -EINTR for fatal
>  signal
> 
> __get_user_pages_locked() will return 0 instead of -EINTR after commit
> 4426e945df588 which added extra code to allow gup detect fatal signal
> faster.  Restore that behavior.
> 
> CC: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
> Signed-off-by: Hillf Danton <hdanton@xxxxxxxx>
> [peterx: write commit message]

Fixes: 4426e945df58 ("mm/gup: allow VM_FAULT_RETRY for multiple times")
> Signed-off-by: Peter Xu <peterx@xxxxxxxxxx>

Acked-by: Michal Hocko <mhocko@xxxxxxxx>

> ---
>  mm/gup.c | 5 ++++-
>  1 file changed, 4 insertions(+), 1 deletion(-)
> 
> diff --git a/mm/gup.c b/mm/gup.c
> index afce0bc47e70..6076df8e04a4 100644
> --- a/mm/gup.c
> +++ b/mm/gup.c
> @@ -1326,8 +1326,11 @@ static __always_inline long __get_user_pages_locked(struct task_struct *tsk,
>  		 * start trying again otherwise it can loop forever.
>  		 */
>  
> -		if (fatal_signal_pending(current))
> +		if (fatal_signal_pending(current)) {
> +			if (!pages_done)
> +				pages_done = -EINTR;
>  			break;
> +		}
>  
>  		ret = down_read_killable(&mm->mmap_sem);
>  		if (ret) {
> -- 
> 2.24.1
> 
> 
> -- 
> Peter Xu
> 

-- 
Michal Hocko
SUSE Labs