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From: Jiri Kosina <jkosina@suse.cz>
To: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Michal Hocko <mhocko@suse.cz>,
	Glauber Costa <glommer@parallels.com>,
	linux-kernel@vger.kernel.org, devel@openvz.org,
	linux-mm@kvack.org, cgroups@vger.kernel.org,
	Johannes Weiner <hannes@cmpxchg.org>,
	kamezawa.hiroyu@jp.fujitsu.com, Greg Thelen <gthelen@google.com>,
	Suleiman Souhlal <suleiman@google.com>,
	Andrew Morton <akpm@linux-foundation.org>
Subject: Re: [PATCH] remove BUG() in possible but rare condition
Date: Wed, 11 Apr 2012 23:33:07 +0200 (CEST)	[thread overview]
Message-ID: <alpine.LRH.2.00.1204112331290.1415@twin.jikos.cz> (raw)
In-Reply-To: <CA+55aFx1GMWGgh0sTAzvvVSzPQsQ_4NKeaNv1zpKrP4fg1dG+Q@mail.gmail.com>

On Wed, 11 Apr 2012, Linus Torvalds wrote:

> > I am not familiar with the code much but a trivial call chain walk up to
> > write_dev_supers (in btrfs) shows that we do not check for the return value
> > from __getblk so we would nullptr and there might be more.
> > I guess these need some treat before the BUG might be removed, right?
> 
> Well, realistically, isn't BUG() as bad as a NULL pointer dereference?

Well, there still could be weirdos out there not setting 
sys.vm.mmap_min_addr to something sane. For those, NULL pointer 
dereference could have worse consequences than BUG (unlikely in this 
particular case, yes).

-- 
Jiri Kosina
SUSE Labs

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  parent reply	other threads:[~2012-04-11 21:33 UTC|newest]

Thread overview: 14+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2012-04-11 18:10 Glauber Costa
2012-04-11 18:48 ` Michal Hocko
2012-04-11 18:57   ` Linus Torvalds
2012-04-11 19:02     ` Glauber Costa
2012-04-11 19:25       ` Michal Hocko
2012-04-11 19:20     ` Michal Hocko
2012-04-11 19:48       ` Don Morris
2012-04-11 21:33     ` Jiri Kosina [this message]
2012-04-11 18:59   ` Glauber Costa
2012-04-11 20:26 ` Andrew Morton
2012-04-11 20:51   ` Glauber Costa
2012-04-11 21:12     ` Andrew Morton
2012-04-11 21:26       ` Michal Hocko
2012-04-12  9:24 ` Michal Hocko

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