linux-kernel - Re: [RFC PATCH v2 0/7] signal: sigprocmask fixes

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: <20110418173224.GA27918@redhat.com>
Date:	Mon, 18 Apr 2011 19:32:24 +0200
From:	Oleg Nesterov <oleg@...hat.com>
To:	Linus Torvalds <torvalds@...ux-foundation.org>
Cc:	Tejun Heo <tj@...nel.org>,
	Andrew Morton <akpm@...ux-foundation.org>,
	"Nikita V. Youshchenko" <nyoushchenko@...sta.com>,
	Matt Fleming <matt@...sole-pimps.org>,
	linux-kernel@...r.kernel.org
Subject: Re: [RFC PATCH v2 0/7] signal: sigprocmask fixes

On 04/18, Linus Torvalds wrote:
>
> On Mon, Apr 18, 2011 at 6:44 AM, Oleg Nesterov <oleg@...hat.com> wrote:
> >
> > Once again: if we need this, then we need a lot more (trivial) changes
> > like 6/7 and 7/7. Basically every change of ->blocked should be converted
> > to use set_current_blocked(). OTOH, perhaps this makes sense by itself.
>
> Hmm. The more I think about this, the less I like it.
>
> What if the pending thread signal was thread-specific to begin with?

These patches should not change the current behaviour in this case.
We never try to re-target the thread-specific signals. Note that
retarget_shared_pending() checks ->signal->shared_pending only.

> For example, if we have a SIGFPE and a SIGKILL that happen at the same
> time, a dying task may have a SIGFPE pending when it dies, and that
> SIGFPE should _not_ be just distributed out to the other threads in
> the thread group.

Yes, and it won't be.

Btw, we do not need to distribute SIGKILL too, we can change
retarget_shared_pending() to remove SIGKILL from shared_pending.
But this only matters when the caller is exit_signals(), and in
this case it should likely notice signal_group_exit() unless
SIGKILL (in unlikely case) it comes in between.

Or I misunderstood?

Oleg.

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/