From: "H. Peter Anvin" <hpa@zytor.com>
To: Ingo Molnar <mingo@elte.hu>
Cc: Petr Tesarik <ptesarik@suse.cz>,
Jeremy Fitzhardinge <jeremy@goop.org>,
LKML <linux-kernel@vger.kernel.org>
Subject: Re: [PATCH] x86: remove unneeded endless loop in BUG()
Date: Thu, 19 Feb 2009 11:53:30 -0800 [thread overview]
Message-ID: <499DB8BA.3050708@zytor.com> (raw)
In-Reply-To: <20090219185935.GA21820@elte.hu>
Ingo Molnar wrote:
>
> the problem is that the DO_BUG() will generate the u2d
> instruction into a random place where GCC puts it. It certainly
> wont be in the place where the __bug_table logic above expects
> it.
>
> The result will be cryptic crashes instead of a clean BUG
> message assert.
>
For that to happen, it would have to move the asm volatile relative to
the __builtin_trap(), which seems slightly unlikely -- are there any
cases at which this has been known to happen, or is that conjecture on
your part?
It would be more of a "right thing" to do this with a label on the
__builtin_trap(), but the problem with that labels have function scope
even if they occur inside a block.
-hpa
next prev parent reply other threads:[~2009-02-19 19:57 UTC|newest]
Thread overview: 9+ messages / expand[flat|nested] mbox.gz Atom feed top
2009-02-19 18:38 [PATCH] x86: remove unneeded endless loop in BUG() Petr Tesarik
2009-02-19 18:40 ` H. Peter Anvin
2009-02-19 18:59 ` Ingo Molnar
2009-02-19 19:53 ` H. Peter Anvin [this message]
2009-02-19 20:47 ` Jeremy Fitzhardinge
2009-02-19 20:48 ` H. Peter Anvin
2009-02-20 8:28 ` Petr Tesarik
2009-02-19 20:29 ` H. Peter Anvin
2009-02-19 20:32 ` Ingo Molnar
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