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From: Luigi Rizzo <lrizzo@google.com>
To: Will Deacon <will@kernel.org>,
	linux-kernel@vger.kernel.org, Joerg Roedel <joro@8bytes.org>,
	David Rientjes <rientjes@google.com>,
	rizzo.unipi@gmail.com,
	Suravee Suthikulpanit <suravee.suthikulpanit@amd.com>
Cc: Luigi Rizzo <lrizzo@google.com>
Subject: [PATCH] amd/iommu: fix logic bug in amd_iommu_report_page_fault()
Date: Sat, 31 Jul 2021 12:26:37 -0700	[thread overview]
Message-ID: <20210731192637.3653796-1-lrizzo@google.com> (raw)

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@google.com>
---
 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


             reply	other threads:[~2021-07-31 19:26 UTC|newest]

Thread overview: 6+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-07-31 19:26 Luigi Rizzo [this message]
2021-08-02  3:52 ` David Rientjes
2021-08-02 14:13 ` Joerg Roedel
2021-08-02 14:30   ` Luigi Rizzo
2021-08-02 14:38     ` Joerg Roedel
2021-08-02 15:26       ` Luigi Rizzo

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