Messages in this thread | | | Date | Thu, 23 May 2013 09:00:45 +0800 | From | Chen Gang <> | Subject | Re: [PATCH] kernel/sched/core.c: need return NULL when BUG() is defined as empty. |
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On 05/23/2013 12:19 AM, Peter Zijlstra wrote: > On Wed, May 22, 2013 at 02:33:17PM +0100, Russell King - ARM Linux wrote: >> > On Wed, May 22, 2013 at 11:11:56AM +0200, Peter Zijlstra wrote: >>> > > On Mon, May 20, 2013 at 03:48:53PM +0800, Chen Gang wrote: >>>> > > > >>>> > > > When neither CONFIG_BUG nor HAVE_ARCH_BUG is defined, need let function >>>> > > > return failure value ('NULL') instead of random value. >>> > > >>> > > What will such a kernel do? Happily continue running whenever we hit a >>> > > BUG? that seems like a particularly bad idea. Should we not have a stub >>> > > BUG() function like: >>> > > >>> > > void BUG(void) __attribute__((noreturn)) >>> > > { >>> > > local_irq_disable(); >>> > > while (1) ; >>> > > } >> > >> > Eww. So you've a platform where you have things like panic_on_oops >> > enabled, and you hit this bug... do we really want to just stop? >> > Wouldn't replacing BUG() with panic("BUG"); be better ? >> > >> > But, this begs the question - what is the point of being able to turn >> > off BUG() ? As BUG() on any sensible architecture is implemented by >> > placing the minimum of code at the callsite (eg, one instruction if >> > not using verbose) anything like the above is likely to be bigger. >> > >> > So, I'd actually argue that rather than trying to "fix" this, get rid >> > of CONFIG_BUG and make it always enabled everywhere - just like what >> > has recently been done with hotplug. > Works for me. >
Thanks all, I should send the related patch for it.
Excuse me, I have to do another things, so I will finish it within this week (2013-05-26)
Welcome any additional suggestions and completions.
Thanks. -- Chen Gang
Asianux Corporation
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