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From: Arnd Bergmann <arnd-r2nGTMty4D4@public.gmane.org>
To: Russell King - ARM Linux <linux-lFZ/pmaqli7XmaaqVzeoHQ@public.gmane.org>
Cc: Linux-sh list <linux-sh-u79uwXL29TY76Z2rM5mHXA@public.gmane.org>,
	Catalin Marinas <Catalin.Marinas-5wv7dgnIgG8@public.gmane.org>,
	Benjamin Herrenschmidt
	<benh-XVmvHMARGAS8U2dJNN8I7kB+6BGkLq7r@public.gmane.org>,
	Chen Gang <gang.chen-bOixZGp5f+dBDgjK7y7TUQ@public.gmane.org>,
	Heiko Carstens
	<heiko.carstens-tA70FqPdS9bQT0dZR+AlfA@public.gmane.org>,
	"paulus-eUNUBHrolfbYtjvyW6yDsg@public.gmane.org"
	<paulus-eUNUBHrolfbYtjvyW6yDsg@public.gmane.org>,
	"H. Peter Anvin" <hpa-YMNOUZJC4hwAvxtiuMwx3w@public.gmane.org>,
	Michel Lespinasse
	<walken-hpIqsD4AKlfQT0dZR+AlfA@public.gmane.org>,
	Hans-Christian Egtvedt
	<egtvedt-BrfabpQBY5qlHtIdYg32fQ@public.gmane.org>,
	Linux-Arch <linux-arch-u79uwXL29TY76Z2rM5mHXA@public.gmane.org>,
	linux-s390-u79uwXL29TY76Z2rM5mHXA@public.gmane.org,
	Yoshinori Sato
	<ysato-Rn4VEauK+AKRv+LV9MX5uooqe+aC9MnS@public.gmane.org>,
	Richard Weinberger <richard-/L3Ra7n9ekc@public.gmane.org>,
	Helge Deller <deller-Mmb7MZpHnFY@public.gmane.org>,
	the arch/x86 maintainers
	<x86-DgEjT+Ai2ygdnm+yROfE0A@public.gmane.org>,
	"James E.J. Bottomley"
	<jejb-6jwH94ZQLHl74goWV3ctuw@public.gmane.org>,
	"mingo-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org"
	<mingo-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org>,
	Geert Uytterhoeven
	<geert-Td1EMuHUCqxL1ZNQvxDV9g@public.gmane.org>,
	Frederic Weisbecker
	<fweisbec-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org>
Subject: Re: [PATCH] arch: configuration, deleting 'CONFIG_BUG' since always need it.
Date: Thu, 23 May 2013 14:09:02 +0200	[thread overview]
Message-ID: <201305231409.02359.arnd@arndb.de> (raw)
In-Reply-To: <20130523112401.GO18614-l+eeeJia6m9vn6HldHNs0ANdhmdF6hFW@public.gmane.org>

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.

> If you have an embedded system and you've taken out all the printk()
> stuff, you most certainly want the system to do something if you hit
> an unexpected condition.

I did not claim that it was a good idea to disable BUG(), all I said is
that "random stuff may happen" is probably what Matt Mackall had in mind when
he introduced the option.

	Arnd

  parent reply	other threads:[~2013-05-23 12:09 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 [this message]
2013-05-23 12:50                       ` Russell King - ARM Linux
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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