linux-kernel - Re: [RFC] exit: do exit_task_work() before shooting off mm

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: <d00c5e71-76c9-3b95-7d3b-e88b990d3682@gmail.com>
Date:   Tue, 8 Dec 2020 03:00:59 +0000
From:   Pavel Begunkov <asml.silence@...il.com>
To:     Al Viro <viro@...iv.linux.org.uk>
Cc:     linux-kernel@...r.kernel.org, Jens Axboe <axboe@...nel.dk>
Subject: Re: [RFC] exit: do exit_task_work() before shooting off mm

On 08/12/2020 01:37, Al Viro wrote:
> On Thu, Dec 03, 2020 at 02:30:46AM +0000, Pavel Begunkov wrote:
>> Handle task works and lock it earlier before it starts killing off
>> task's resources like mm. io_uring makes use of it a lot and it'd
>> nicer to have all added task_work finding tasks in a consistent state.
>>
>> Signed-off-by: Pavel Begunkov <asml.silence@...il.com>
>> ---
>>
>> Would it be correct? I clearly don't know all the exit invariants, but
>> can't find any users relying on task_works in-between.
> 
> You've just gotten rid of exit_task_work() anywhere after exit_files().
> And exit_mm() can trigger the final fput() just as easily as exit_files().
> 
> IOW, you have just made the effect of final close on exit() completely
> asynchronous.
> 
> NAK.

Ok, that's why it was a question. Thanks for making it clear

-- 
Pavel Begunkov