[PATCH 1/1] drm/amdgpu: Unlock bo_list_mutex after error handling

[Christian König]

Am 03.11.22 um 15:59 schrieb Philip Yang:
> Get below kernel WARNING backtrace when pressing ctrl-C to kill kfdtest
> application.
>
> If amdgpu_cs_parser_bos returns error after taking bo_list_mutex, as
> caller amdgpu_cs_ioctl will not unlock bo_list_mutex, this generates the
> kernel WARNING.
>
> Add unlock bo_list_mutex after amdgpu_cs_parser_bos error handling to
> cleanup bo_list userptr bo.
>
>   WARNING: kfdtest/2930 still has locks held!
>   1 lock held by kfdtest/2930:
>    (&list->bo_list_mutex){+.+.}-{3:3}, at: amdgpu_cs_ioctl+0xce5/0x1f10 [amdgpu]
>    stack backtrace:
>     dump_stack_lvl+0x44/0x57
>     get_signal+0x79f/0xd00
>     arch_do_signal_or_restart+0x36/0x7b0
>     exit_to_user_mode_prepare+0xfd/0x1b0
>     syscall_exit_to_user_mode+0x19/0x40
>     do_syscall_64+0x40/0x80
>
> Signed-off-by: Philip Yang <Philip.Yang at amd.com>

Good catch, patch is Reviewed-by: Christian König <christian.koenig at amd.com>

> ---
>   drivers/gpu/drm/amd/amdgpu/amdgpu_cs.c | 1 +
>   1 file changed, 1 insertion(+)
>
> diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_cs.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_cs.c
> index 1bbd39b3b0fc..d371000a5727 100644
> --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_cs.c
> +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_cs.c
> @@ -992,6 +992,7 @@ static int amdgpu_cs_parser_bos(struct amdgpu_cs_parser *p,
>   		kvfree(e->user_pages);
>   		e->user_pages = NULL;
>   	}
> +	mutex_unlock(&p->bo_list->bo_list_mutex);
>   	return r;
>   }
>