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 for Android: free password hash cracker in your pocket
[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]
Message-ID: <CAHk-=whpkWbdeZE1zask8YPzVYevJU2xOXqOposBujxZsa2-tQ@mail.gmail.com>
Date:   Mon, 16 Jan 2023 10:00:52 -0800
From:   Linus Torvalds <torvalds@...ux-foundation.org>
To:     Byungchul Park <byungchul.park@....com>
Cc:     linux-kernel@...r.kernel.org, damien.lemoal@...nsource.wdc.com,
        linux-ide@...r.kernel.org, adilger.kernel@...ger.ca,
        linux-ext4@...r.kernel.org, mingo@...hat.com, peterz@...radead.org,
        will@...nel.org, tglx@...utronix.de, rostedt@...dmis.org,
        joel@...lfernandes.org, sashal@...nel.org, daniel.vetter@...ll.ch,
        duyuyang@...il.com, johannes.berg@...el.com, tj@...nel.org,
        tytso@....edu, willy@...radead.org, david@...morbit.com,
        amir73il@...il.com, gregkh@...uxfoundation.org,
        kernel-team@....com, linux-mm@...ck.org, akpm@...ux-foundation.org,
        mhocko@...nel.org, minchan@...nel.org, hannes@...xchg.org,
        vdavydov.dev@...il.com, sj@...nel.org, jglisse@...hat.com,
        dennis@...nel.org, cl@...ux.com, penberg@...nel.org,
        rientjes@...gle.com, vbabka@...e.cz, ngupta@...are.org,
        linux-block@...r.kernel.org, paolo.valente@...aro.org,
        josef@...icpanda.com, linux-fsdevel@...r.kernel.org,
        viro@...iv.linux.org.uk, jack@...e.cz, jlayton@...nel.org,
        dan.j.williams@...el.com, hch@...radead.org, djwong@...nel.org,
        dri-devel@...ts.freedesktop.org, rodrigosiqueiramelo@...il.com,
        melissa.srw@...il.com, hamohammed.sa@...il.com,
        42.hyeyoo@...il.com, chris.p.wilson@...el.com,
        gwan-gyeong.mun@...el.com
Subject: Re: [PATCH RFC v7 00/23] DEPT(Dependency Tracker)

[ Back from travel, so trying to make sense of this series.. ]

On Sun, Jan 8, 2023 at 7:33 PM Byungchul Park <byungchul.park@....com> wrote:
>
> I've been developing a tool for detecting deadlock possibilities by
> tracking wait/event rather than lock(?) acquisition order to try to
> cover all synchonization machanisms. It's done on v6.2-rc2.

Ugh. I hate how this adds random patterns like

        if (timeout == MAX_SCHEDULE_TIMEOUT)
                sdt_might_sleep_strong(NULL);
        else
                sdt_might_sleep_strong_timeout(NULL);
   ...
        sdt_might_sleep_finish();

to various places, it seems so very odd and unmaintainable.

I also recall this giving a fair amount of false positives, are they all fixed?

Anyway, I'd really like the lockdep people to comment and be involved.
We did have a fairly recent case of "lockdep doesn't track page lock
dependencies because it fundamentally cannot" issue, so DEPT might fix
those kinds of missing dependency analysis. See

    https://lore.kernel.org/lkml/00000000000060d41f05f139aa44@google.com/

for some context to that one, but at teh same time I would *really*
want the lockdep people more involved and acking this work.

Maybe I missed the email where you reported on things DEPT has found
(and on the lack of false positives)?

               Linus

Powered by blists - more mailing lists

Powered by Openwall GNU/*/Linux Powered by OpenVZ