Hi Marc,
On Fri, Aug 14, 2015 at 03:41:07PM +0100, Marc Zyngier wrote:
> When find_and_init_phbs() looks for the probe-only property, it seems
> to trust the firmware to be correctly written, and assumes that there
> is a parameter to the property.
>
> It is conceivable that the firmware could not be that perfect, and it
> could expose this property naked (at least one arm64 platform seems to
> exhibit this exact behaviour). The setup code the ends up making
> a decision based on whatever the property pointer points to, which
> is likely to be junk.
>
> Instead, let's check for the validity of the property, and ignore
> it if the firmware couldn't make up its mind.
>
> Signed-off-by: Marc Zyngier <marc.zyngier@xxxxxxx>
> ---
> arch/powerpc/platforms/pseries/setup.c | 15 ++++++++++-----
> 1 file changed, 10 insertions(+), 5 deletions(-)
>
> diff --git a/arch/powerpc/platforms/pseries/setup.c b/arch/powerpc/platforms/pseries/setup.c
> index df6a704..6bdc1f9 100644
> --- a/arch/powerpc/platforms/pseries/setup.c
> +++ b/arch/powerpc/platforms/pseries/setup.c
> @@ -490,14 +490,19 @@ static void __init find_and_init_phbs(void)
> */
> if (of_chosen) {
> const int *prop;
> + int len;
>
> prop = of_get_property(of_chosen,
> - "linux,pci-probe-only", NULL);
> + "linux,pci-probe-only", &len);
> if (prop) {
> - if (*prop)
> - pci_add_flags(PCI_PROBE_ONLY);
> - else
> - pci_clear_flags(PCI_PROBE_ONLY);
> + if (len) {
> + if (be32_to_cpup(prop))
> + pci_add_flags(PCI_PROBE_ONLY);
> + else
> + pci_clear_flags(PCI_PROBE_ONLY);
> + } else {
> + pr_warn("linux,pci-probe-only set without value, ignoring\n");
> + }
This seems essentially identical to the pci-host-generic version.
Is there a way we can factor it out so there's only one copy?
> }
> }
> }
> --
> 2.1.4
>
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