linux-kernel - Re: [PATCH] oom: Make coredump interruptible

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: <20100602185812.4B5894A549@magilla.sf.frob.com>
Date:	Wed,  2 Jun 2010 11:58:12 -0700 (PDT)
From:	Roland McGrath <roland@...hat.com>
To:	Oleg Nesterov <oleg@...hat.com>
Cc:	KOSAKI Motohiro <kosaki.motohiro@...fujitsu.com>,
	LKML <linux-kernel@...r.kernel.org>,
	linux-mm <linux-mm@...ck.org>,
	David Rientjes <rientjes@...gle.com>,
	Andrew Morton <akpm@...ux-foundation.org>,
	KAMEZAWA Hiroyuki <kamezawa.hiroyu@...fujitsu.com>,
	Nick Piggin <npiggin@...e.de>
Subject: Re: [PATCH] oom: Make coredump interruptible

> Because it is per-thread.

I see.

> when select_bad_process() finds the task P to kill it can participate
> in the core dump (sleep in exit_mm), but we should somehow inform the
> thread which actually dumps the core: P->mm->core_state->dumper.

Perhaps it should simply do that: if you would choose P to oom-kill, and
P->mm->core_state!=NULL, then choose P->mm->core_state->dumper instead.

> Well, we can use TIF_MEMDIE if we chose the right thread, I think.
> But perhaps mm->flags |= MMF_OOM is better, it can have other user.
> I dunno.

This is all the quick hack before get around to just making core dumping
fully-interruptible, no?  So we should go with whatever is the simplest
change now.

Perhaps this belongs in another thread as you suggested.  But I wonder what
we might get just from s/TASK_UNINTERRUPTIBLE/TASK_KILLABLE/ in exit_mm.


Thanks,
Roland
--
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/