2020-07-13 16:56:00

by Saheed O. Bolarinwa

[permalink] [raw]
Subject: [PATCH 12/14 v3] PCI/AER: Check the return value of pcie_capability_read_*()

From: Bolarinwa Olayemi Saheed <[email protected]>

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 <[email protected]>
Signed-off-by: Bolarinwa Olayemi Saheed <[email protected]>
---
drivers/pci/pcie/aer.c | 5 +++--
1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/drivers/pci/pcie/aer.c b/drivers/pci/pcie/aer.c
index 3acf56683915..f4beb47c622c 100644
--- a/drivers/pci/pcie/aer.c
+++ b/drivers/pci/pcie/aer.c
@@ -800,6 +800,7 @@ static bool is_error_source(struct pci_dev *dev, struct aer_err_info *e_info)
int aer = dev->aer_cap;
u32 status, mask;
u16 reg16;
+ int ret;

/*
* When bus id is equal to 0, it might be a bad id
@@ -828,8 +829,8 @@ static bool is_error_source(struct pci_dev *dev, struct aer_err_info *e_info)
return false;

/* Check if AER is enabled */
- pcie_capability_read_word(dev, PCI_EXP_DEVCTL, &reg16);
- if (!(reg16 & PCI_EXP_AER_FLAGS))
+ ret = pcie_capability_read_word(dev, PCI_EXP_DEVCTL, &reg16);
+ if (ret || !(reg16 & PCI_EXP_AER_FLAGS))
return false;

if (!aer)
--
2.18.2