linux-kernel - Re: [PATCH v2] ring-buffer: Prevent inconsistent operation on cpu_buffer->resize

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <b05d80ab-fd72-1346-f5d9-b80ae9b5cd1a@gmail.com>
Date:   Sun, 9 Apr 2023 19:30:53 +0700
From:   Bagas Sanjaya <bagasdotme@...il.com>
To:     Tze-nan Wu <Tze-nan.Wu@...iatek.com>, rostedt@...dmis.org,
        mhiramat@...nel.org
Cc:     bobule.chang@...iatek.com, wsd_upstream@...iatek.com,
        stable@...r.kernel.org,
        AngeloGioacchino Del Regno 
        <angelogioacchino.delregno@...labora.com>,
        linux-kernel@...r.kernel.org, linux-trace-kernel@...r.kernel.org,
        linux-arm-kernel@...ts.infradead.org,
        linux-mediatek@...ts.infradead.org
Subject: Re: [PATCH v2] ring-buffer: Prevent inconsistent operation on
 cpu_buffer->resize_disabled

On 4/9/23 09:46, Tze-nan Wu wrote:
> This issue can be reproduced by "echo 0 > trace" and hotplug cpu at the
> same time. After reproducing success, we can find out buffer_size_kb
> will not be functional anymore.
> 

Do you mean disabling tracing while hotplugging CPU? Or disabling both
tracing and hotplug CPU?

> This patch uses cpus_read_lock() to prevent cpu_online_mask being changed
> between two different "for_each_online_buffer_cpu".
> 

"Use cpu_read_lock() to prevent ..."

> Changes in v2:
>   Use cpus_read_lock() instead of copying cpu_online_mask at the entry of
>   function
> 

To resolve kernel test robot warnings ([1] and [2])? Or have they been fixed?

[1]: https://lore.kernel.org/stable/202304081615.eiaqpbV8-lkp@intel.com/
[2]: https://lore.kernel.org/stable/202304082051.Dp50upfS-lkp@intel.com/

Thanks.

-- 
An old man doll... just what I always wanted! - Clara