linux-kernel - Re: Definition of BUG on x86

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: <499DA727.2060606@zytor.com>
Date:	Thu, 19 Feb 2009 10:38:31 -0800
From:	"H. Peter Anvin" <hpa@...or.com>
To:	Petr Tesarik <ptesarik@...e.cz>
CC:	Jeremy Fitzhardinge <jeremy@...p.org>,
	LKML <linux-kernel@...r.kernel.org>
Subject: Re: Definition of BUG on x86

Petr Tesarik wrote:
> 
> Ah, yes, you're right. If you want to make gcc aware of the fact that a
> function never returns, it must recognize that there is no path to that
> function's EXIT, otherwise it will emit a warning (which is pretty
> annoying, indeed). Since we don't want to make a call/jmp to an external
> noreturn function, so the no-return code must be directly visible to
> gcc. Unfortunately, there is no way of telling gcc that an asm statement
> does not return.
> 

At Transmeta, we had an internal hack to gcc that added
__builtin_not_reached(); for this particular reason.  This would
probably be the best way to handle this.

	-hpa

-- 
H. Peter Anvin, Intel Open Source Technology Center
I work for Intel.  I don't speak on their behalf.

--
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/