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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 15/17] iommu/vt-d: Remove BUG_ON in map/unmap()
Date:   Thu, 13 Apr 2023 12:06:43 +0800
Message-Id: <20230413040645.46157-16-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>

Domain map/unmap with invalid parameters shouldn't crash the kernel.
Therefore, using if() replaces the BUG_ON.

Signed-off-by: Tina Zhang <tina.zhang@intel.com>
Link: https://lore.kernel.org/r/20230406065944.2773296-6-tina.zhang@intel.com
Signed-off-by: Lu Baolu <baolu.lu@linux.intel.com>
---
 drivers/iommu/intel/iommu.c | 8 +++++---
 1 file changed, 5 insertions(+), 3 deletions(-)

diff --git a/drivers/iommu/intel/iommu.c b/drivers/iommu/intel/iommu.c
index f11347a590d7..ab21ef1ddb3c 100644
--- a/drivers/iommu/intel/iommu.c
+++ b/drivers/iommu/intel/iommu.c
@@ -2159,7 +2159,8 @@ __domain_mapping(struct dmar_domain *domain, unsigned long iov_pfn,
 	phys_addr_t pteval;
 	u64 attr;
 
-	BUG_ON(!domain_pfn_supported(domain, iov_pfn + nr_pages - 1));
+	if (unlikely(!domain_pfn_supported(domain, iov_pfn + nr_pages - 1)))
+		return -EINVAL;
 
 	if ((prot & (DMA_PTE_READ|DMA_PTE_WRITE)) == 0)
 		return -EINVAL;
@@ -4314,8 +4315,9 @@ static size_t intel_iommu_unmap(struct iommu_domain *domain,
 
 	/* Cope with horrid API which requires us to unmap more than the
 	   size argument if it happens to be a large-page mapping. */
-	BUG_ON(!pfn_to_dma_pte(dmar_domain, iova >> VTD_PAGE_SHIFT, &level,
-			       GFP_ATOMIC));
+	if (unlikely(!pfn_to_dma_pte(dmar_domain, iova >> VTD_PAGE_SHIFT,
+				     &level, GFP_ATOMIC)))
+		return 0;
 
 	if (size < VTD_PAGE_SIZE << level_to_offset_bits(level))
 		size = VTD_PAGE_SIZE << level_to_offset_bits(level);
-- 
2.34.1