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>,
"Benjamin Herrenschmidt" <benh@kernel.crashing.org>,
"Chen Gang" <gang.chen@asianux.com>,
"Heiko Carstens" <heiko.carstens@de.ibm.com>,
"paulus@samba.org" <paulus@samba.org>,
"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>,
"Frederic Weisbecker" <fweisbec@gmail.com>,
"Paul McKenney" <paulmck@linux.vnet.ibm.com>,
"Håvard Skinnemoen" <hskinnemoen@gmail.com>
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.
next prev parent reply other threads:[~2013-05-23 12:50 UTC|newest]
Thread overview: 29+ 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 7:57 ` Chen Gang
2013-05-23 8:40 ` Geert Uytterhoeven
2013-05-23 8:54 ` Arnd Bergmann
[not found] ` <CAMuHMdU7QuzgmWCH145p8PVebBzPo8DBAvbY+0AZa2cmGXmRHw-JsoAwUIsXosN+BqQ9rBEUg@public.gmane.org>
2013-05-23 9:05 ` Russell King - ARM Linux
2013-05-23 9:12 ` Geert Uytterhoeven
2013-05-23 9:39 ` Arnd Bergmann
[not found] ` <201305231139.38233.arnd-r2nGTMty4D4@public.gmane.org>
2013-05-23 10:04 ` Russell King - ARM Linux
2013-05-23 10:41 ` Chen Gang
2013-05-23 10:59 ` Arnd Bergmann
[not found] ` <201305231259.43750.arnd-r2nGTMty4D4@public.gmane.org>
2013-05-23 11:19 ` Chen Gang
2013-05-23 11:24 ` Russell King - ARM Linux
[not found] ` <20130523112401.GO18614-l+eeeJia6m9vn6HldHNs0ANdhmdF6hFW@public.gmane.org>
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
[not found] ` <20130528081910.GA29557-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org>
2013-05-28 14:55 ` H. Peter Anvin
2013-05-28 15:43 ` Arnd Bergmann
[not found] ` <201305281743.52649.arnd-r2nGTMty4D4@public.gmane.org>
2013-05-28 16:06 ` H. Peter Anvin
[not found] ` <51A4D618.3080208-YMNOUZJC4hwAvxtiuMwx3w@public.gmane.org>
2013-05-28 17:20 ` Arnd Bergmann
2013-05-23 10:09 ` Eric W. Biederman
[not found] ` <878v369fdd.fsf-aS9lmoZGLiVWk0Htik3J/w@public.gmane.org>
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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