From mboxrd@z Thu Jan  1 00:00:00 1970
Return-Path: <linux-kernel-owner@vger.kernel.org>
Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand
        id S1751594AbdISKib (ORCPT <rfc822;w@1wt.eu>);
        Tue, 19 Sep 2017 06:38:31 -0400
Received: from mail-pf0-f172.google.com ([209.85.192.172]:54219 "EHLO
        mail-pf0-f172.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org
        with ESMTP id S1751306AbdISKia (ORCPT
        <rfc822;linux-kernel@vger.kernel.org>);
        Tue, 19 Sep 2017 06:38:30 -0400
X-Google-Smtp-Source: AOwi7QA29SINXaQ/Z27UPlj2zdjSzglX4/oUki5d2XQnPk77UQd9+FAwhBK+1bmUYuPe7aZSfJetWg==
Date: Tue, 19 Sep 2017 19:38:25 +0900
From: Sergey Senozhatsky <sergey.senozhatsky.work@gmail.com>
To: Sergey Senozhatsky <sergey.senozhatsky.work@gmail.com>
Cc: Minchan Kim <minchan@kernel.org>,
        Andrew Morton <akpm@linux-foundation.org>,
        linux-kernel@vger.kernel.org, kernel-team <kernel-team@lge.com>,
        Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
Subject: BUG_ON when zsmalloc from IRQ (was zram: fix null dereference of
 handle)
Message-ID: <20170919103825.GD401@jagdpanzerIV.localdomain>
References: <20170919102125.GB401@jagdpanzerIV.localdomain>
MIME-Version: 1.0
Content-Type: text/plain; charset=us-ascii
Content-Disposition: inline
In-Reply-To: <20170919102125.GB401@jagdpanzerIV.localdomain>
User-Agent: Mutt/1.9.0 (2017-09-02)
Sender: linux-kernel-owner@vger.kernel.org
List-ID: <linux-kernel.vger.kernel.org>
X-Mailing-List: linux-kernel@vger.kernel.org

ah... this should have had another Subject line....
sorry.

	-ss

On (09/19/17 19:21), Sergey Senozhatsky wrote:
> Minchan,
> 
> I just ran across it [because I had a bug to analize where this
> part was involved]. I'd really prefer the kernel to BUG_ON immediately
> instead of dying in agony.
> 
> can we, please, return BUG_ON() back?
> 
> there is no point in trying to save the kernel once it did that type
> of violation.
> 
> ---
> 
> diff --git a/mm/zsmalloc.c b/mm/zsmalloc.c
> index 7c38e850a8fc..685049a9048d 100644
> --- a/mm/zsmalloc.c
> +++ b/mm/zsmalloc.c
> @@ -1349,7 +1349,7 @@ void *zs_map_object(struct zs_pool *pool, unsigned long handle,
>          * pools/users, we can't allow mapping in interrupt context
>          * because it can corrupt another users mappings.
>          */
> -       WARN_ON_ONCE(in_interrupt());
> +       BUG_ON(in_interrupt());
>  
>         /* From now on, migration cannot move the object */
>         pin_tag(handle);
>