| Message ID | 152996758037.260522.6880919949506497973.stgit@bhelgaas-glaptop.roam.corp.google.com (mailing list archive) |
|---|---|
| State | New, archived |
| Delegated to: | Bjorn Helgaas |
| Headers | show |
On 25/06/18 23:59, Bjorn Helgaas wrote: > From: Bjorn Helgaas <bhelgaas@google.com> > > If acpi_pci_find_root() returns NULL, it means there's no ACPI host bridge > device (PNP0A03 or PNP0A08), and the OS is always allowed to manage the > SHPC, so return success in that case. > > This fixes a NULL pointer dereference when CONFIG_ACPI=y but the current > hardware/firmware platform doesn't support ACPI. In that case, > acpi_get_hp_hw_control_from_firmware() is implemented but > acpi_pci_find_root() returns NULL. > > Fixes: 90cc0c3cc709 ("PCI: shpchp: Add shpchp_is_native()") > Link: https://lkml.kernel.org/r/20180621164715.28160-1-marc.zyngier@arm.com > Reported-by: Marc Zyngier <marc.zyngier@arm.com> > Signed-off-by: Bjorn Helgaas <bhelgaas@google.com> Tested-by: Marc Zyngier <marc.zyngier@arm.com> Thanks for the quick turnaround! M.
diff --git a/drivers/pci/hotplug/acpi_pcihp.c b/drivers/pci/hotplug/acpi_pcihp.c index 3979f89b250a..5bd6c1573295 100644 --- a/drivers/pci/hotplug/acpi_pcihp.c +++ b/drivers/pci/hotplug/acpi_pcihp.c @@ -7,7 +7,6 @@ * All rights reserved. * * Send feedback to <kristen.c.accardi@intel.com> - * */ #include <linux/module.h> @@ -87,8 +86,17 @@ int acpi_get_hp_hw_control_from_firmware(struct pci_dev *pdev) return 0; /* If _OSC exists, we should not evaluate OSHP */ + + /* + * If there's no ACPI host bridge (i.e., ACPI support is compiled + * into the kernel but the hardware platform doesn't support ACPI), + * there's nothing to do here. + */ host = pci_find_host_bridge(pdev->bus); root = acpi_pci_find_root(ACPI_HANDLE(&host->dev)); + if (!root) + return 0; + if (root->osc_support_set) goto no_control;