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[81.183.194.223]) by smtp.gmail.com with ESMTPSA id 22sm24216859wmb.11.2020.07.06.03.31.53 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Mon, 06 Jul 2020 03:31:54 -0700 (PDT) From: Saheed Olayemi Bolarinwa To: helgaas@kernel.org Cc: Bolarinwa Olayemi Saheed , bjorn@helgaas.com, skhan@linuxfoundation.org, linux-pci@vger.kernel.org, linux-kernel-mentees@lists.linuxfoundation.org, linux-kernel@vger.kernel.org Subject: [PATCH 4/11 RFC] PCI: pciehp: Validate with the return value of pcie_capability_read_*() Date: Mon, 6 Jul 2020 11:31:14 +0200 Message-Id: <20200706093121.9731-5-refactormyself@gmail.com> X-Mailer: git-send-email 2.18.2 In-Reply-To: <20200706093121.9731-1-refactormyself@gmail.com> References: <20200706093121.9731-1-refactormyself@gmail.com> Sender: linux-pci-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-pci@vger.kernel.org From: Bolarinwa Olayemi Saheed On failure pcie_capability_read_dword() sets it's last parameter, val to 0. However, with Patch 11/11, 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_dword is checked to confirm success. Check the return value of pcie_capability_read_dword() to ensure success. Return a value that indicate the result of pcie_capability_read_dword(). Suggested-by: Bjorn Helgaas Signed-off-by: Bolarinwa Olayemi Saheed --- drivers/pci/hotplug/pciehp_hpc.c | 15 +++++++++------ 1 file changed, 9 insertions(+), 6 deletions(-) diff --git a/drivers/pci/hotplug/pciehp_hpc.c b/drivers/pci/hotplug/pciehp_hpc.c index 5af281d97d4f..0b691e37fd04 100644 --- a/drivers/pci/hotplug/pciehp_hpc.c +++ b/drivers/pci/hotplug/pciehp_hpc.c @@ -277,10 +277,11 @@ static void pcie_wait_for_presence(struct pci_dev *pdev) { int timeout = 1250; u16 slot_status; + int ret; do { - pcie_capability_read_word(pdev, PCI_EXP_SLTSTA, &slot_status); - if (slot_status & PCI_EXP_SLTSTA_PDS) + ret = pcie_capability_read_word(pdev, PCI_EXP_SLTSTA, &slot_status); + if (!ret && (slot_status & PCI_EXP_SLTSTA_PDS)) return; msleep(10); timeout -= 10; @@ -354,12 +355,13 @@ int pciehp_get_raw_indicator_status(struct hotplug_slot *hotplug_slot, struct controller *ctrl = to_ctrl(hotplug_slot); struct pci_dev *pdev = ctrl_dev(ctrl); u16 slot_ctrl; + int ret; pci_config_pm_runtime_get(pdev); - pcie_capability_read_word(pdev, PCI_EXP_SLTCTL, &slot_ctrl); + ret = pcie_capability_read_word(pdev, PCI_EXP_SLTCTL, &slot_ctrl); pci_config_pm_runtime_put(pdev); *status = (slot_ctrl & (PCI_EXP_SLTCTL_AIC | PCI_EXP_SLTCTL_PIC)) >> 6; - return 0; + return pcibios_err_to_errno(ret); } int pciehp_get_attention_status(struct hotplug_slot *hotplug_slot, u8 *status) @@ -367,9 +369,10 @@ int pciehp_get_attention_status(struct hotplug_slot *hotplug_slot, u8 *status) struct controller *ctrl = to_ctrl(hotplug_slot); struct pci_dev *pdev = ctrl_dev(ctrl); u16 slot_ctrl; + int ret; pci_config_pm_runtime_get(pdev); - pcie_capability_read_word(pdev, PCI_EXP_SLTCTL, &slot_ctrl); + ret = pcie_capability_read_word(pdev, PCI_EXP_SLTCTL, &slot_ctrl); pci_config_pm_runtime_put(pdev); ctrl_dbg(ctrl, "%s: SLOTCTRL %x, value read %x\n", __func__, pci_pcie_cap(ctrl->pcie->port) + PCI_EXP_SLTCTL, slot_ctrl); @@ -389,7 +392,7 @@ int pciehp_get_attention_status(struct hotplug_slot *hotplug_slot, u8 *status) break; } - return 0; + return pcibios_err_to_errno(ret); } void pciehp_get_power_status(struct controller *ctrl, u8 *status)