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 for Android: free password hash cracker in your pocket

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

Date:   Wed, 21 Jun 2023 15:42:14 +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


21.06.2023 15:35, Jeff Layton пишет:
> I don't think we can change this at this point.
>
> The bottom line (again) is that OFD locks are owned by the file
> descriptor (much like with flock()), and since file descriptors can be
> shared across multiple process it's impossible to say that some single
> process owns it.
What's the problem with 2 owners?
Can't you get one of them, rather than
meaningless -1?
Compare this situation with read locks.
They can overlap, so when you get an
info about a read lock (except for the
new F_UNLCK case), you get the info
about *some* of the locks in that range.
In the case of multiple owners, you
likewise get the info about about some
owner. If you iteratively send them a
"please release this lock" message
(eg in a form of SIGKILL), then you
traverse all, and end up with the
lock-free area.
Is there really any problem here?