On Mon, Jun 20, 2016 at 09:56:45AM -0700, Tyler Baker wrote:

Hi Bjorn,

On 6 June 2016 at 16:06, Bjorn Helgaas [off-list ref] wrote:

quoted

Previously we allocated the PCI resource list in
gen_pci_parse_request_of_pci_ranges(), but if we had an error, we freed it
on error in gen_pci_init().

Reorder gen_pci_init() so we can take care of error path cleanup in
gen_pci_parse_request_of_pci_ranges() instead.

Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>

The kernelci.org bot has reported[0] new qemu-aarch64
(arm64-defconfig) boot failures[1][2] in next-20160620. I've
bisected[3] this boot failure down to this patch, and confirmed
reverting it on top of next-20160620 resolves the boot issue.

I have not investigated further, but you can easily reproduce[4] the
boot failure on an x86 host running qemu-system-aarch64 (I'm running
qemu-system 2.6).

That's most likely because pci_ecam_create() requires the bus_range
resource (its busr parameter) to be initialized when it is called
and that's not the case after this patch is applied if I read it
correctly.

It is probably a NULL pointer dereference in pci_ecam_create().

Thanks,
Lorenzo

Cheers,

Tyler

[0] https://kernelci.org/boot/all/job/next/kernel/next-20160620/
[1] https://storage.kernelci.org/next/next-20160620/arm64-defconfig/lab-cambridge/boot-apm-mustang-kvm-guest.txt
[2] https://storage.kernelci.org/next/next-20160620/arm64-defconfig/lab-tbaker/boot-qemu-aarch64,legacy.txt
[3] http://hastebin.com/segiruribu.vbs
[4] http://hastebin.com/dafuzicuyi.avrasm
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