From: David Laight <david.laight.linux@gmail.com>
To: Christian Brauner <brauner@kernel.org>
Cc: Oleg Nesterov <oleg@redhat.com>, Jann Horn <jannh@google.com>,
Linus Torvalds <torvalds@linux-foundation.org>,
Ingo Molnar <mingo@redhat.com>,
Peter Zijlstra <peterz@infradead.org>,
linux-kernel@vger.kernel.org, linux-fsdevel@vger.kernel.org
Subject: Re: pidfd && O_RDWR
Date: Tue, 24 Feb 2026 09:43:09 +0000 [thread overview]
Message-ID: <20260224094309.591e7db1@pumpkin> (raw)
In-Reply-To: <20260223-ziemlich-gemalt-0900475140e5@brauner>
On Mon, 23 Feb 2026 22:39:22 +0100
Christian Brauner <brauner@kernel.org> wrote:
> On Mon, Feb 23, 2026 at 08:21:02PM +0100, Oleg Nesterov wrote:
> > On 02/23, Oleg Nesterov wrote:
> > >
> > > pidfd_prepare() does pidfs_alloc_file(pid, flags | O_RDWR) and "| O_RDWR"
> > > makes no sense because pidfs_alloc_file() itself does
> > >
> > > flags |= O_RDWR;
> > >
> > > I was going to send the trivial cleanup, but why a pidfs file needs
> > > O_RDWR/FMODE_WRITE ?
> > >
> > > Actually the same question about some anon_inode_getfile_fmode(O_RDWR)
> > > users, for example signalfd.c.
> >
> > perhaps an accidental legacy from 628ff7c1d8d8 ("anonfd: Allow making anon
> > files read-only") ?
>
> It was always a possibility that we would support some form of
> write-like operation eventually. And we have support for setting trusted
> extended attributes on pidfds for some time now (trusted xattrs require
> global cap_sys_admin).
>
Isn't 'sending a signal' a write-like operation?
David
next prev parent reply other threads:[~2026-02-24 9:43 UTC|newest]
Thread overview: 14+ messages / expand[flat|nested] mbox.gz Atom feed top
2026-02-23 10:44 [PATCH v4 0/4] pidfd: add CLONE_AUTOREAP and CLONE_PIDFD_AUTOKILL Christian Brauner
2026-02-23 10:44 ` [PATCH v4 1/4] clone: add CLONE_AUTOREAP Christian Brauner
2026-02-23 10:44 ` [PATCH v4 2/4] pidfd: add CLONE_PIDFD_AUTOKILL Christian Brauner
2026-02-23 15:47 ` Oleg Nesterov
2026-02-23 15:51 ` Oleg Nesterov
2026-02-23 17:05 ` pidfd && O_RDWR Oleg Nesterov
2026-02-23 18:14 ` David Laight
2026-02-23 19:21 ` Oleg Nesterov
2026-02-23 21:39 ` Christian Brauner
2026-02-24 9:43 ` David Laight [this message]
2026-02-24 10:17 ` Oleg Nesterov
2026-02-24 16:47 ` Christian Brauner
2026-02-23 10:45 ` [PATCH v4 3/4] selftests/pidfd: add CLONE_AUTOREAP tests Christian Brauner
2026-02-23 10:45 ` [PATCH v4 4/4] selftests/pidfd: add CLONE_PIDFD_AUTOKILL tests Christian Brauner
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