| Message ID | 20200713175529.29715-4-refactormyself@gmail.com (mailing list archive) |
|---|---|
| State | Not Applicable, archived |
| Delegated to: | Bjorn Helgaas |
| Headers | show |
| Series | None | expand |
On Mon, Jul 13, 2020 at 6:55 PM Saheed O. Bolarinwa <refactormyself@gmail.com> wrote: > > From: Bolarinwa Olayemi Saheed <refactormyself@gmail.com> > > On failure pcie_capability_read_dword() sets it's last parameter, > val to 0. > However, with Patch 14/14, it is possible that val is set to ~0 on > failure. This would introduce a bug because (x & x) == (~0 & x). > > This bug can be avoided if the return value of pcie_capability_read_word > is checked to confirm success. > > Check the return value of pcie_capability_read_word() to ensure success. > > Suggested-by: Bjorn Helgaas <bjorn@helgaas.com> > Signed-off-by: Bolarinwa Olayemi Saheed <refactormyself@gmail.com> Acked-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> > --- > drivers/pci/pci-acpi.c | 10 ++++++---- > 1 file changed, 6 insertions(+), 4 deletions(-) > > diff --git a/drivers/pci/pci-acpi.c b/drivers/pci/pci-acpi.c > index 7224b1e5f2a8..39eb816bc3b8 100644 > --- a/drivers/pci/pci-acpi.c > +++ b/drivers/pci/pci-acpi.c > @@ -248,12 +248,13 @@ static bool pcie_root_rcb_set(struct pci_dev *dev) > { > struct pci_dev *rp = pcie_find_root_port(dev); > u16 lnkctl; > + int ret; > > if (!rp) > return false; > > - pcie_capability_read_word(rp, PCI_EXP_LNKCTL, &lnkctl); > - if (lnkctl & PCI_EXP_LNKCTL_RCB) > + ret = pcie_capability_read_word(rp, PCI_EXP_LNKCTL, &lnkctl); > + if (!ret && (lnkctl & PCI_EXP_LNKCTL_RCB)) > return true; > > return false; > @@ -792,12 +793,13 @@ bool pciehp_is_native(struct pci_dev *bridge) > { > const struct pci_host_bridge *host; > u32 slot_cap; > + int ret; > > if (!IS_ENABLED(CONFIG_HOTPLUG_PCI_PCIE)) > return false; > > - pcie_capability_read_dword(bridge, PCI_EXP_SLTCAP, &slot_cap); > - if (!(slot_cap & PCI_EXP_SLTCAP_HPC)) > + ret = pcie_capability_read_dword(bridge, PCI_EXP_SLTCAP, &slot_cap); > + if (ret || !(slot_cap & PCI_EXP_SLTCAP_HPC)) > return false; > > if (pcie_ports_native) > -- > 2.18.2 >
diff --git a/drivers/pci/pci-acpi.c b/drivers/pci/pci-acpi.c index 7224b1e5f2a8..39eb816bc3b8 100644 --- a/drivers/pci/pci-acpi.c +++ b/drivers/pci/pci-acpi.c @@ -248,12 +248,13 @@ static bool pcie_root_rcb_set(struct pci_dev *dev) { struct pci_dev *rp = pcie_find_root_port(dev); u16 lnkctl; + int ret; if (!rp) return false; - pcie_capability_read_word(rp, PCI_EXP_LNKCTL, &lnkctl); - if (lnkctl & PCI_EXP_LNKCTL_RCB) + ret = pcie_capability_read_word(rp, PCI_EXP_LNKCTL, &lnkctl); + if (!ret && (lnkctl & PCI_EXP_LNKCTL_RCB)) return true; return false; @@ -792,12 +793,13 @@ bool pciehp_is_native(struct pci_dev *bridge) { const struct pci_host_bridge *host; u32 slot_cap; + int ret; if (!IS_ENABLED(CONFIG_HOTPLUG_PCI_PCIE)) return false; - pcie_capability_read_dword(bridge, PCI_EXP_SLTCAP, &slot_cap); - if (!(slot_cap & PCI_EXP_SLTCAP_HPC)) + ret = pcie_capability_read_dword(bridge, PCI_EXP_SLTCAP, &slot_cap); + if (ret || !(slot_cap & PCI_EXP_SLTCAP_HPC)) return false; if (pcie_ports_native)