[PATCH 15/17] iommu/vt-d: Remove BUG_ON in map/unmap()

Lu Baolu
2023-04-11T06:51:07Z

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