From: Matthew Wilcox <matthew@wil.cx>
To: linux-ia64@vger.kernel.org
Subject: Re: Unable to do IA64 stacktrace in early boot
Date: Thu, 21 Dec 2006 05:03:47 +0000 [thread overview]
Message-ID: <20061221050347.GT21070@parisc-linux.org> (raw)
In-Reply-To: <5478.1166673370@kao2.melbourne.sgi.com>
On Thu, Dec 21, 2006 at 02:56:10PM +1100, Keith Owens wrote:
> double unlock: ok | ok |failed|WARNING at /build/kaos/kernel.org-sgidev/linux/kernel/mutex-debug.c:83 debug_mutex_unlock()
> Unable to handle kernel NULL pointer dereference (address 0000000000000000)
>
> 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.
next prev parent reply other threads:[~2006-12-21 5:03 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 [this message]
2006-12-21 14:44 ` Ingo Molnar
2006-12-21 22:03 ` David Mosberger-Tang
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