| Message ID | 1441385411-7624-4-git-send-email-marc.zyngier@arm.com (mailing list archive) |
|---|---|
| State | New, archived |
| Delegated to: | Bjorn Helgaas |
| Headers | show |
On Fri, 2015-09-04 at 17:50 +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, switch to the common of_pci.c implementation that doesn't > suffer from this problem and ignore the property if the firmware > couldn't make up its mind. > > Signed-off-by: Marc Zyngier <marc.zyngier@arm.com> > --- > arch/powerpc/platforms/pseries/setup.c | 14 ++------------ Thanks. I can't find any powerpc machine that is currently using this, or much info on what ever did use it, so I think it's pretty low impact, and the change looks sane. Acked-by: Michael Ellerman <mpe@ellerman.id.au> cheers -- To unsubscribe from this list: send the line "unsubscribe linux-pci" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
diff --git a/arch/powerpc/platforms/pseries/setup.c b/arch/powerpc/platforms/pseries/setup.c index 39a74fa..6016709 100644 --- a/arch/powerpc/platforms/pseries/setup.c +++ b/arch/powerpc/platforms/pseries/setup.c @@ -40,6 +40,7 @@ #include <linux/seq_file.h> #include <linux/root_dev.h> #include <linux/of.h> +#include <linux/of_pci.h> #include <linux/kexec.h> #include <asm/mmu.h> @@ -495,18 +496,7 @@ static void __init find_and_init_phbs(void) * PCI_PROBE_ONLY and PCI_REASSIGN_ALL_BUS can be set via properties * in chosen. */ - if (of_chosen) { - const int *prop; - - prop = of_get_property(of_chosen, - "linux,pci-probe-only", NULL); - if (prop) { - if (*prop) - pci_add_flags(PCI_PROBE_ONLY); - else - pci_clear_flags(PCI_PROBE_ONLY); - } - } + of_pci_check_probe_only(); } static void __init pSeries_setup_arch(void)
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, switch to the common of_pci.c implementation that doesn't suffer from this problem and ignore the property if the firmware couldn't make up its mind. Signed-off-by: Marc Zyngier <marc.zyngier@arm.com> --- arch/powerpc/platforms/pseries/setup.c | 14 ++------------ 1 file changed, 2 insertions(+), 12 deletions(-)