Messages in this thread | | | Date | Thu, 2 Feb 2012 13:27:42 +0100 | From | Heiko Carstens <> | Subject | Re: rcu warnings cause stack overflow |
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On Wed, Feb 01, 2012 at 04:14:48PM +0100, Frederic Weisbecker wrote: > > Removing the WARN_ON_ONCE will fix this and, if lockdep is turned on, still > > will find illegal uses. But it won't work for lockdep off configs... > > So we probably want something better than the patch below. > > Ah ok. Hmm, but why are you using an exception to implement WARN_ON() > in s390? Is it to have a whole new stack for the warning path in order > to avoid stack overflow from the place that called the WARN_ON() ?
The reason was to reduce the code footprint of the WARN_ON() and also be able to print the register contents at the time the warning happened.
All architectures which define __WARN_TAINT implement warnings with exceptions. Currently that are parisc, powerpc, s390 and sh.
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