From: Ingo Molnar <mingo@redhat.com>
To: linux-ia64@vger.kernel.org
Subject: Re: Unable to do IA64 stacktrace in early boot
Date: Thu, 21 Dec 2006 14:44:04 +0000 [thread overview]
Message-ID: <1166712244.8869.18.camel@earth> (raw)
In-Reply-To: <5478.1166673370@kao2.melbourne.sgi.com>
On Wed, 2006-12-20 at 22:03 -0700, Matthew Wilcox wrote:
> > mutex-debug uses DEBUG_LOCKS_WARN_ON() which indirectly calls
> > dump_stack which the IA64 unwind code (arch/ia64/kernel/unwind.c)
> calls
> > kmalloc. The lockdep tests are run before the slab caches have been
> > allocated so cpu_cache_get is called with a NULL cachep, hence the
> > oops.
>
> Yup. I just debugged and fixed the same problem on parisc. I didn't
> think to check ia64; I checked to see what x86-64 did. Unfortunately,
> the ia64 unwind code seems a lot more subtle and more allocation-happy
> than the parisc unwind code, so I'm not sure exactly how to fix ia64.
yeah. calling kmalloc() within the unwinder is a no-no. What if the
unwind happens while kmalloc() is crashing?
Ingo
>
next prev parent reply other threads:[~2006-12-21 14:44 UTC|newest]
Thread overview: 4+ messages / expand[flat|nested] mbox.gz Atom feed top
2006-12-21 3:56 Unable to do IA64 stacktrace in early boot Keith Owens
2006-12-21 5:03 ` Matthew Wilcox
2006-12-21 14:44 ` Ingo Molnar [this message]
2006-12-21 22:03 ` David Mosberger-Tang
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