[PATCH 2/2] iommu/vt-d: Use BUG_ON to check NULL value of 'table'

From: Yanfei Xu
Date: Tue May 30 2023 - 05:29:01 EST


Checking NULL value of 'table' variable deserves a BUG_ON as the
following code will trigger a crash by dereferencing the NULL
'table' pointer. Crash in advance with BUG_ON to avoid WARN_ON
plus NULL pointer dereferencing can simplify the crash log.

Signed-off-by: Yanfei Xu <yanfei.xu@xxxxxxxxx>
---
drivers/iommu/intel/iommu.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/iommu/intel/iommu.c b/drivers/iommu/intel/iommu.c
index e98f1b122b49..8aa3bfdb7f95 100644
--- a/drivers/iommu/intel/iommu.c
+++ b/drivers/iommu/intel/iommu.c
@@ -1944,7 +1944,7 @@ static int domain_context_mapping_one(struct dmar_domain *domain,
if (sm_supported(iommu)) {
unsigned long pds;

- WARN_ON(!table);
+ BUG_ON(!table);

/* Setup the PASID DIR pointer: */
pds = context_get_sm_pds(table);
--
2.34.1