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From:   Lu Baolu <baolu.lu@linux.intel.com>
To:     Joerg Roedel <joro@8bytes.org>
Cc:     Tina Zhang <tina.zhang@intel.com>,
        Jacob Pan <jacob.jun.pan@linux.intel.com>,
        Christophe JAILLET <christophe.jaillet@wanadoo.fr>,
        iommu@lists.linux.dev, linux-kernel@vger.kernel.org
Subject: [PATCH v2 12/17] iommu/vt-d: Remove BUG_ON on checking valid pfn range
Date:   Thu, 13 Apr 2023 12:06:40 +0800
Message-Id: <20230413040645.46157-13-baolu.lu@linux.intel.com>
In-Reply-To: <20230413040645.46157-1-baolu.lu@linux.intel.com>
References: <20230413040645.46157-1-baolu.lu@linux.intel.com>
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From: Tina Zhang <tina.zhang@intel.com>

When encountering an unexpected invalid pfn range, the kernel should
attempt recovery and proceed with execution. Therefore, using WARN_ON to
replace BUG_ON to avoid halting the machine.

Besides, one redundant checking is reduced.

Signed-off-by: Tina Zhang <tina.zhang@intel.com>
Link: https://lore.kernel.org/r/20230406065944.2773296-3-tina.zhang@intel.com
Signed-off-by: Lu Baolu <baolu.lu@linux.intel.com>
---
 drivers/iommu/intel/iommu.c | 12 ++++++------
 1 file changed, 6 insertions(+), 6 deletions(-)

diff --git a/drivers/iommu/intel/iommu.c b/drivers/iommu/intel/iommu.c
index acbf82fa90e7..c4847a5aaf52 100644
--- a/drivers/iommu/intel/iommu.c
+++ b/drivers/iommu/intel/iommu.c
@@ -1005,9 +1005,9 @@ static void dma_pte_clear_range(struct dmar_domain *domain,
 	unsigned int large_page;
 	struct dma_pte *first_pte, *pte;
 
-	BUG_ON(!domain_pfn_supported(domain, start_pfn));
-	BUG_ON(!domain_pfn_supported(domain, last_pfn));
-	BUG_ON(start_pfn > last_pfn);
+	if (WARN_ON(!domain_pfn_supported(domain, last_pfn)) ||
+	    WARN_ON(start_pfn > last_pfn))
+		return;
 
 	/* we don't need lock here; nobody else touches the iova range */
 	do {
@@ -1166,9 +1166,9 @@ static void dma_pte_clear_level(struct dmar_domain *domain, int level,
 static void domain_unmap(struct dmar_domain *domain, unsigned long start_pfn,
 			 unsigned long last_pfn, struct list_head *freelist)
 {
-	BUG_ON(!domain_pfn_supported(domain, start_pfn));
-	BUG_ON(!domain_pfn_supported(domain, last_pfn));
-	BUG_ON(start_pfn > last_pfn);
+	if (WARN_ON(!domain_pfn_supported(domain, last_pfn)) ||
+	    WARN_ON(start_pfn > last_pfn))
+		return;
 
 	/* we don't need lock here; nobody else touches the iova range */
 	dma_pte_clear_level(domain, agaw_to_level(domain->agaw),
-- 
2.34.1