From: Oleg Nesterov <oleg@redhat.com>
To: "Jürg Billeter" <j@bitron.ch>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>,
Andrew Morton <akpm@linux-foundation.org>,
Thomas Gleixner <tglx@linutronix.de>,
Kees Cook <keescook@chromium.org>,
Andy Lutomirski <luto@kernel.org>,
linux-api@vger.kernel.org, linux-kernel@vger.kernel.org
Subject: Re: [PATCH] prctl: add PR_{GET,SET}_KILL_DESCENDANTS_ON_EXIT
Date: Fri, 30 Nov 2018 11:33:30 +0100 [thread overview]
Message-ID: <20181130103329.GB23670@redhat.com> (raw)
In-Reply-To: <f55261dbc41544363b4348820f67fb01c6d7aaec.camel@bitron.ch>
On 11/29, Jürg Billeter wrote:
>
> On Thu, 2018-11-29 at 13:34 +0100, Oleg Nesterov wrote:
> > To me it would be more clean to call walk_process_tree(kill_descendant_visitor)
> > unconditionally in find_new_reaper() right before "if (has_child_subreaper)", but
> > then we will need to shift read_lock(tasklist) from walk_process_tree().
>
> Yes, that's the reason why I added the call before the tasklist lock.
> Let me know if you want me to move the read lock from
> walk_process_tree() to PR_SET_CHILD_SUBREAPER (the only caller)
> instead.
I am fine either way. We can do this later, lets keep your patch simple.
> > So I think the patch is mostly fine, the only problem I can see is that
> > PR_SET_KILL_DESCENDANTS_ON_EXIT can race with PR_SET_CHILD_SUBREAPER, they both
> > need to update the bits in the same word.
>
> Good point. I'll make it a regular bool instead of a bitfield for v2,
Agreed,
> unless you have another approach in mind to fix this.
Well, I think that is_child_subreaper/has_child_subreaper and the new
kill_descendants_on_exit should live in signal->flags, but we need some
cleanups to make this possible, so I agree with the boolean.
Oleg.
next prev parent reply other threads:[~2018-11-30 10:33 UTC|newest]
Thread overview: 19+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-11-27 22:54 [PATCH 0/1] Add prctl to kill descendants on exit Jürg Billeter
2018-11-27 22:54 ` [PATCH] prctl: add PR_{GET,SET}_KILL_DESCENDANTS_ON_EXIT Jürg Billeter
2018-11-28 14:42 ` Oleg Nesterov
2018-11-28 15:23 ` Eric W. Biederman
2018-11-29 12:34 ` Oleg Nesterov
2018-11-29 15:41 ` Jürg Billeter
2018-11-30 10:33 ` Oleg Nesterov [this message]
2018-12-01 4:28 ` Kees Cook
2018-11-30 8:00 ` [PATCH v2 0/1] Add prctl to kill descendants on exit Jürg Billeter
2018-11-30 8:00 ` [PATCH v2 1/1] prctl: add PR_{GET,SET}_KILL_DESCENDANTS_ON_EXIT Jürg Billeter
2018-11-30 11:22 ` Oleg Nesterov
2018-11-30 13:40 ` Florian Weimer
2018-12-01 10:39 ` Jürg Billeter
2018-12-01 12:28 ` Florian Weimer
2018-12-01 13:57 ` Jürg Billeter
2018-12-06 15:54 ` [PATCH v2 0/1] Add prctl to kill descendants on exit Jürg Billeter
2019-01-18 13:11 ` [RESEND PATCH " Jürg Billeter
2019-01-18 13:11 ` [RESEND PATCH v2 1/1] prctl: add PR_{GET,SET}_KILL_DESCENDANTS_ON_EXIT Jürg Billeter
2019-01-29 1:23 ` Andrew Morton
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=20181130103329.GB23670@redhat.com \
--to=oleg@redhat.com \
--cc=akpm@linux-foundation.org \
--cc=ebiederm@xmission.com \
--cc=j@bitron.ch \
--cc=keescook@chromium.org \
--cc=linux-api@vger.kernel.org \
--cc=linux-kernel@vger.kernel.org \
--cc=luto@kernel.org \
--cc=tglx@linutronix.de \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.