[PATCH] amd/iommu: fix logic bug in amd_iommu_report_page_fault()

From: Luigi Rizzo
Date: Sat Jul 31 2021 - 15:27:57 EST


amd_iommu_report_page_fault() has two print paths, depending on whether or
not it can find a pci device. But the code erroneously enters the second
path if the rate limiter in the first path triggers:
if (dev_data && ratelimit(A)) { A; } else if (ratelimit(B)) { B; }
The correct code should be
if (dev_data) { if (ratelimit(A)) { A;} } else if (ratelimit(B)) { B; }

Signed-off-by: Luigi Rizzo <lrizzo@xxxxxxxxxx>
---
drivers/iommu/amd/iommu.c | 8 +++++---
1 file changed, 5 insertions(+), 3 deletions(-)

diff --git a/drivers/iommu/amd/iommu.c b/drivers/iommu/amd/iommu.c
index 811a49a95d04..38b4aff70800 100644
--- a/drivers/iommu/amd/iommu.c
+++ b/drivers/iommu/amd/iommu.c
@@ -480,9 +480,11 @@ static void amd_iommu_report_page_fault(u16 devid, u16 domain_id,
if (pdev)
dev_data = dev_iommu_priv_get(&pdev->dev);

- if (dev_data && __ratelimit(&dev_data->rs)) {
- pci_err(pdev, "Event logged [IO_PAGE_FAULT domain=0x%04x address=0x%llx flags=0x%04x]\n",
- domain_id, address, flags);
+ if (dev_data) {
+ if (__ratelimit(&dev_data->rs)) {
+ pci_err(pdev, "Event logged [IO_PAGE_FAULT domain=0x%04x address=0x%llx flags=0x%04x]\n",
+ domain_id, address, flags);
+ }
} else if (printk_ratelimit()) {
pr_err("Event logged [IO_PAGE_FAULT device=%02x:%02x.%x domain=0x%04x address=0x%llx flags=0x%04x]\n",
PCI_BUS_NUM(devid), PCI_SLOT(devid), PCI_FUNC(devid),
--
2.32.0.554.ge1b32706d8-goog