linux-kernel - Re: [PATCH 1/2] mailbox: Use per-thread completion to fix wrong completion order

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: <CABb+yY3CBiLpZ1KrD8RFypRgkP9MOzBf1FB+gL2E-qEuSbrj6A@mail.gmail.com>
Date: Sun, 20 Jul 2025 16:13:09 -0500
From: Jassi Brar <jassisinghbrar@...il.com>
To: Joonwon Kang <joonwonkang@...gle.com>
Cc: thierry.reding@...il.com, alexey.klimov@....com, sudeep.holla@....com, 
	jonathanh@...dia.com, linux-kernel@...r.kernel.org, 
	linux-tegra@...r.kernel.org
Subject: Re: [PATCH 1/2] mailbox: Use per-thread completion to fix wrong
 completion order

On Wed, Jun 18, 2025 at 3:04 AM Joonwon Kang <joonwonkang@...gle.com> wrote:
>
> Previously, a sender thread in mbox_send_message() could be woken up at
> a wrong time in blocking mode. It is because there was only a single
> completion for a channel whereas messages from multiple threads could be
> sent in any order; since the shared completion could be signalled in any
> order, it could wake up a wrong sender thread.
>
> This commit resolves the false wake-up issue with the following changes:
> - Completions are created as many as the number of concurrent sender
>   threads
> - A completion is created in a sender thread's stack
> - Each slot of the message queue, i.e. `msg_data`, contains a pointer to
>   its target completion
> - tx_tick() signals the completion of the currently active slot of the
>   message queue
>
> Link: https://lore.kernel.org/all/1490809381-28869-1-git-send-email-jaswinder.singh@linaro.org

Is your issue different from what is described in the Link?

thanks