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To: Darren Stevens <darren@stevens-zone.net>, linuxppc-dev@lists.ozlabs.org
From: Michael Ellerman <patch-notifications@ellerman.id.au>
Cc: Pat Wall <pjwall@mac.com>, rtd@a-eon.com, aperez@alexperez.com,
 Christian Zigotzky <chzigotzky@xenosoft.de>
Subject: Re: powerpc: Add missing error check to prom_find_boot_cpu()
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Date: Fri, 27 Jan 2017 11:33:00 +1100 (AEDT)
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On Mon, 2017-01-23 at 19:42:54 UTC, Darren Stevens wrote:
> prom_init.c calls 'instance-to-package' twice, but the return
> is not checked during prom_find_boot_cpu(). The result is then
> passed to prom_getprop, which could be PROM_ERROR.
> Add a return check to prevent this.
> 
> This was found on a pasemi system, where CFE doesn't have a working
> 'instance-to package' prom call.
> Before Commit 5c0484e25ec0 ('powerpc: Endian safe trampoline') the
> area around addr 0 as mostly 0's and this doesn't cause a problem.
> Once the macro 'FIXUP_ENDIAN' has been added to head_64.S, the low
> memory area now has non-zero values, which cause the prom_getprop
> call to hang.
> 
> Signed-off-by: Darren Stevens <darren@stevens-zone.net>

Applied to powerpc fixes, thanks.

https://git.kernel.org/powerpc/c/af2b7fa17eb92e52b65f96604448ff

cheers