Versatile Express randomly fails to boot - Russell King

From: linux@arm.linux.org.uk (Russell King - ARM Linux)
To: linux-arm-kernel@lists.infradead.org
Subject: Versatile Express randomly fails to boot
Date: Mon, 16 Mar 2015 09:35:53 +0000	[thread overview]
Message-ID: <20150316093553.GF8656@n2100.arm.linux.org.uk> (raw)
In-Reply-To: <20150316004239.GE8656@n2100.arm.linux.org.uk>

On Mon, Mar 16, 2015 at 12:42:39AM +0000, Russell King - ARM Linux wrote:
> On Mon, Mar 16, 2015 at 12:04:38AM +0000, Russell King - ARM Linux wrote:
> > On Sun, Mar 15, 2015 at 09:33:30PM +0000, Russell King - ARM Linux wrote:
> > > I'm going to try a few other kernels to try and track down what's going
> > > on - whether something from arm-soc or my tree is responsible for this
> > > really weird behaviour.
> > 
> > Okay, this is weird - it seems that it's caused by the FIQ oops
> > dumping code/FIQ changes which I've carried for many months
> > unchanged in my tree.
> 
> More weirdness.  Progressing forwards through my development code
> showed that when I merged the patch I mentioned in the previous mail,
> things started to fail.
> 
> As I also mentioned, I'd drop that branch (two patches, one adding
> the IPI backtrace stuff and the second one updating the GIC to allow
> it to raise FIQs on suitably equipped platforms.)  I would have
> expected that to have worked, but it just failed after four boot
> iterations.  So either it's not the FIQ, or it is the FIQ code _and_
> also something else.  Or it has something to do with the placement
> of functions in the kernel.
> 
> I'll try more stuff tomorrow, working from where I presently am
> (which is basically last night's code minus the FIQ changes) by
> removing other changes to see what brings us back to a working
> system.
> 
> As I've already said - this is really weird because all of these
> changes were also tested against -rc1... those which weren't are:
> 
> mm: fold arch_randomize_brk into ARCH_HAS_ELF_RANDOMIZE
> mm: split ET_DYN ASLR from mmap ASLR
> mm: move randomize_et_dyn into ELF_ET_DYN_BASE
> mm: expose arch_mmap_rnd when available
> arm: factor out mmap ASLR into mmap_rnd
> 
> and a number of clkdev rework patches (to make it use clk_hw
> internally.)  Neither of these should be affecting it, but that's
> something I will be testing tomorrow.

Okay, reverting the ASLR changes and the clkdev changes annoyingly still
results in random failure.

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