linux-kernel - Re: [PATCH] pidfd: change pidfd_send_signal() to respect PIDFD

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: <20240208140610.GE19801@redhat.com>
Date: Thu, 8 Feb 2024 15:06:10 +0100
From: Oleg Nesterov <oleg@...hat.com>
To: Christian Brauner <brauner@...nel.org>
Cc: Andy Lutomirski <luto@...capital.net>,
	"Eric W. Biederman" <ebiederm@...ssion.com>,
	Tycho Andersen <tycho@...ho.pizza>, linux-api@...r.kernel.org,
	linux-kernel@...r.kernel.org
Subject: Re: [PATCH] pidfd: change pidfd_send_signal() to respect PIDFD_THREAD

On 02/08, Christian Brauner wrote:
>
> I would also suggest we update the obsolete comment on top of
> pidfd_send_signal() along the lines of:

Yes, but...

> + * If the @pidfd refers to a thread-group leader the signal is thread-group
> + * directed. If @pidfd referes to a thread then the signal is thread directed.

No, this depends on PIDFD_THREAD only.

If it is set then the signal is always "thread directed" even if @pidfd refers
to a thread-group leader.

Otherwise the target task must be a group leader and the signal will be
"thread-group directed".

Right?

Oleg.