[PATCH 12/17] iommu/vt-d: Remove BUG_ON on checking valid pfn range

Lu Baolu
2023-04-11T06:50:47Z

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