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From: Russell King - ARM Linux <linux@arm.linux.org.uk>
To: Arnd Bergmann <arnd@arndb.de>
Cc: "Catalin Marinas" <Catalin.Marinas@arm.com>,
	"Linux-sh list" <linux-sh@vger.kernel.org>,
	"Chen Gang" <gang.chen@asianux.com>,
	"Heiko Carstens" <heiko.carstens@de.ibm.com>,
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	"H. Peter Anvin" <hpa@zytor.com>,
	"Michel Lespinasse" <walken@google.com>,
	"Hans-Christian Egtvedt" <egtvedt@samfundet.no>,
	Linux-Arch <linux-arch@vger.kernel.org>,
	linux-s390@vger.kernel.org,
	"Yoshinori Sato" <ysato@users.sourceforge.jp>,
	"Richard Weinberger" <richard@nod.at>,
	"Helge Deller" <deller@gmx.de>,
	"the arch/x86 maintainers" <x86@kernel.org>,
	"James E.J. Bottomley" <jejb@parisc-linux.org>,
	"mingo@redhat.com" <mingo@redhat.com>,
	"Geert Uytterhoeven" <geert@linux-m68k.org>,
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	linux-hexagon@vger.kernel.org,
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	linux390@de.ibm.com, "Andrew Morton" <akpm@linux-foundation.org>,
	"linuxppc-dev@lists.ozlabs.org" <linuxppc-dev@lists.ozlabs.org>,
	"David Miller" <davem@davemloft.net>
Subject: Re: [PATCH] arch: configuration, deleting 'CONFIG_BUG' since always need it.
Date: Thu, 23 May 2013 13:50:33 +0100	[thread overview]
Message-ID: <20130523125033.GP18614@n2100.arm.linux.org.uk> (raw)
In-Reply-To: <201305231409.02359.arnd@arndb.de>

On Thu, May 23, 2013 at 02:09:02PM +0200, Arnd Bergmann wrote:
> On Thursday 23 May 2013, Russell King - ARM Linux wrote:
> > This is the problem you guys are missing - unreachable() means "we lose
> > control of the CPU at this point".
> 
> I'm absolutely aware of this. Again, the current behaviour of doing nothing
> at all isn't very different from undefined behavior when you get when you
> get to the end of a function returning a pointer without a "return" statement,
> or when you return from a function that has determined that it is not safe
> to continue.

Running off the end of a function like that is a different kettle of fish.
The execution path is still as the compiler intends - what isn't is that
the data returned is likely to be random trash.

That's _quite_ different from the CPU starting to execute the contents
of a literal data pool.

  reply	other threads:[~2013-05-23 12:55 UTC|newest]

Thread overview: 28+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2013-05-23  7:57 [PATCH] arch: configuration, deleting 'CONFIG_BUG' since always need it Chen Gang
2013-05-23  8:40 ` Geert Uytterhoeven
2013-05-23  8:54   ` Arnd Bergmann
2013-05-23  9:05   ` Russell King - ARM Linux
2013-05-23  9:12     ` Geert Uytterhoeven
2013-05-23  9:39       ` Arnd Bergmann
2013-05-23 10:04         ` Russell King - ARM Linux
2013-05-23 10:41           ` Chen Gang
2013-05-23 10:59           ` Arnd Bergmann
2013-05-23 11:19             ` Chen Gang
2013-05-23 11:24             ` Russell King - ARM Linux
2013-05-23 12:09               ` Arnd Bergmann
2013-05-23 12:50                 ` Russell King - ARM Linux [this message]
2013-05-23 14:10                   ` Geert Uytterhoeven
2013-05-24  2:13                     ` Chen Gang
2013-05-24  4:17                       ` Chen Gang
2013-05-26  4:43                         ` [PATCH v2] arch: configuration issue, random return value when disable 'CONFIG_BUG' Chen Gang
2013-05-28  8:19           ` [PATCH] arch: configuration, deleting 'CONFIG_BUG' since always need it Ingo Molnar
2013-05-28 10:25             ` Chen Gang
2013-05-28 14:49             ` Arnd Bergmann
2013-05-28 14:55             ` H. Peter Anvin
2013-05-28 15:43               ` Arnd Bergmann
2013-05-28 16:06                 ` H. Peter Anvin
2013-05-28 17:20                   ` Arnd Bergmann
2013-05-23 10:09         ` Eric W. Biederman
2013-05-23 10:29           ` Russell King - ARM Linux
2013-05-23 10:05       ` Chen Gang
2013-05-24  5:59 ` Eric W. Biederman

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