[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]
Message-ID: <20240126143349.GD7386@redhat.com>
Date: Fri, 26 Jan 2024 15:33:50 +0100
From: Oleg Nesterov <oleg@...hat.com>
To: Christian Brauner <brauner@...nel.org>
Cc: Tycho Andersen <tycho@...ho.pizza>, linux-kernel@...r.kernel.org,
linux-api@...r.kernel.org, Tycho Andersen <tandersen@...flix.com>,
"Eric W. Biederman" <ebiederm@...ssion.com>
Subject: Re: [PATCH v3 1/3] pidfd: allow pidfd_open() on non-thread-group
leaders
On 01/26, Christian Brauner wrote:
>
> > --- a/include/uapi/linux/pidfd.h
> > +++ b/include/uapi/linux/pidfd.h
> > @@ -7,6 +7,7 @@
> > #include <linux/fcntl.h>
> >
> > /* Flags for pidfd_open(). */
> > -#define PIDFD_NONBLOCK O_NONBLOCK
> > +#define PIDFD_NONBLOCK O_NONBLOCK
> > +#define PIDFD_THREAD O_EXCL // or anything else not used by anon_inode's
>
> I like it!
>
> The only request I would have is to not alias O_EXCL and PIDFD_THREAD.
> Because it doesn't map as clearly as NONBLOCK did.
But it would be nice to have PIDFD_THREAD in file->f_flags. Where else
can we keep it?
I chose O_EXCL because it can only be used at open time, it can never
be used or changed after anon_inode_getfile(), so we can safely do
pidfd_file->f_flags |= PIDFD_THREAD;
in __pidfd_prepare() and then check in pidfd_poll/pidfd_send_signal.
What do you suggest instead?
Oleg.
Powered by blists - more mailing lists