From: Saheed Olayemi Bolarinwa <refactormyself@gmail.com>
To: helgaas@kernel.org
Cc: Bolarinwa Olayemi Saheed <refactormyself@gmail.com>,
linux-kernel@vger.kernel.org, linux-pci@vger.kernel.org,
linux-kernel-mentees@lists.linuxfoundation.org
Subject: [Linux-kernel-mentees] [PATCH 8/13] PCI: pciehp: Check return value of pcie_capability_read_*()
Date: Wed, 8 Jul 2020 00:03:19 +0200 [thread overview]
Message-ID: <20200707220324.8425-9-refactormyself@gmail.com> (raw)
In-Reply-To: <20200707220324.8425-1-refactormyself@gmail.com>
From: Bolarinwa Olayemi Saheed <refactormyself@gmail.com>
On failure pcie_capability_read_dword() sets it's last parameter,
val to 0.
However, with Patch 13/13, 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_dword() to ensure success.
Return a value that indicate the result of pcie_capability_read_word().
Suggested-by: Bjorn Helgaas <bjorn@helgaas.com>
Signed-off-by: Bolarinwa Olayemi Saheed <refactormyself@gmail.com>
---
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)
--
2.18.2
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next prev parent reply other threads:[~2020-07-07 23:03 UTC|newest]
Thread overview: 10+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-07-07 22:03 [Linux-kernel-mentees] [PATCH 0/13] PCI: Remove '*val = 0' from pcie_capability_read_*() Saheed Olayemi Bolarinwa
2020-07-07 22:03 ` [Linux-kernel-mentees] [PATCH 2/13] misc: rtsx: Check the return value of pcie_capability_read_*() Saheed Olayemi Bolarinwa
2020-07-08 6:53 ` Greg Kroah-Hartman
2020-07-07 22:03 ` [Linux-kernel-mentees] [PATCH 5/13] PCI: pciehp: " Saheed Olayemi Bolarinwa
2020-07-07 22:03 ` [Linux-kernel-mentees] [PATCH 6/13] PCI: pciehp: Make "Power On" the default Saheed Olayemi Bolarinwa
2020-07-07 22:03 ` Saheed Olayemi Bolarinwa [this message]
2020-07-07 22:03 ` [Linux-kernel-mentees] [PATCH 9/13] PCI: Check return value of pcie_capability_read_*() Saheed Olayemi Bolarinwa
2020-07-07 22:03 ` [Linux-kernel-mentees] [PATCH 10/13] PCI/PM: " Saheed Olayemi Bolarinwa
2020-07-07 22:03 ` [Linux-kernel-mentees] [PATCH 12/13] PCI/ASPM: Check the " Saheed Olayemi Bolarinwa
2020-07-07 22:03 ` [Linux-kernel-mentees] [PATCH 13/13] PCI: Remove '*val = 0' from pcie_capability_read_*() Saheed Olayemi Bolarinwa
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