linux-kernel - Re: [PATCH 2/3] fd/locks: allow get the lock owner by F_OFD

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: <9c0a7cde-da32-bc09-0724-5b1387909d18@yandex.ru>
Date:   Wed, 21 Jun 2023 11:57:45 +0500
From:   stsp <stsp2@...dex.ru>
To:     Jeff Layton <jlayton@...nel.org>, linux-kernel@...r.kernel.org
Cc:     Chuck Lever <chuck.lever@...cle.com>,
        Alexander Viro <viro@...iv.linux.org.uk>,
        Christian Brauner <brauner@...nel.org>,
        linux-fsdevel@...r.kernel.org, Matthew Wilcox <willy@...radead.org>
Subject: Re: [PATCH 2/3] fd/locks: allow get the lock owner by F_OFD_GETLK


20.06.2023 18:58, Jeff Layton пишет:
> No, it won't. The l_pid field is populated from the file_lock->fl_pid.
> That field is set when the lock is set, and never updated. So it's quite
> possible for F_GETLK to return the pid of a process that no longer
> exists.
>
> In principle, we could try to address that by changing how we track lock
> ownership, but that's a fairly major overhaul, and I'm not clear on any
> use-cases where that matters.

OK, in this case I'll just put a comments
into the code, summarizing the info I got
from you and Matthew.
Thanks guys for all the info, its very helpful.

Now I only need to convert the current
"fundamental problem" attitude into a "not
implemented yet" via the code comment.


>> So my call is to be brave and just re-consider
>> the conclusion of that article, made 10 years
>> ago! :)
>>
> I think my foot has too many bullet wounds for that sort of bravery.
I am perfectly fine with leaving this thing
unimplemented. But what really bothers
me is the posix proposal, which I think was
done. Please tell me it allows fixing fl_pid
in the future (rather than to mandate -1),
and I am calm.