From: Kees Cook <keesc...@chromium.org>

The find.h APIs are designed to be used only on unsigned long arguments.
This can technically result in a over-read, but it is harmless in this
case. Regardless, fix it to avoid the warning seen under -Warray-bounds,
which we'd like to enable globally:

In file included from ./include/linux/bitmap.h:9,
                 from drivers/iommu/intel/iommu.c:17:
drivers/iommu/intel/iommu.c: In function 'domain_context_mapping_one':
./include/linux/find.h:119:37: warning: array subscript 'long unsigned int[0]' 
is partly outside array bounds of 'int[1]' [-Warray-bounds]
  119 |                 unsigned long val = *addr & GENMASK(size - 1, 0);
      |                                     ^~~~~
drivers/iommu/intel/iommu.c:2115:18: note: while referencing 'max_pde'
 2115 |         int pds, max_pde;
      |                  ^~~~~~~

Signed-off-by: Kees Cook <keesc...@chromium.org>
Acked-by: Yury Norov <yury.no...@gmail.com>
Link: https://lore.kernel.org/r/20211215232432.2069605-1-keesc...@chromium.org
Signed-off-by: Lu Baolu <baolu...@linux.intel.com>
---
 drivers/iommu/intel/iommu.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/iommu/intel/iommu.c b/drivers/iommu/intel/iommu.c
index 73ad4578de25..56671c7f4c08 100644
--- a/drivers/iommu/intel/iommu.c
+++ b/drivers/iommu/intel/iommu.c
@@ -2102,10 +2102,10 @@ static void domain_exit(struct dmar_domain *domain)
  */
 static inline unsigned long context_get_sm_pds(struct pasid_table *table)
 {
-       int pds, max_pde;
+       unsigned long pds, max_pde;
 
        max_pde = table->max_pasid >> PASID_PDE_SHIFT;
-       pds = find_first_bit((unsigned long *)&max_pde, MAX_NR_PASID_BITS);
+       pds = find_first_bit(&max_pde, MAX_NR_PASID_BITS);
        if (pds < 7)
                return 0;
 
-- 
2.25.1

_______________________________________________
iommu mailing list
iommu@lists.linux-foundation.org
https://lists.linuxfoundation.org/mailman/listinfo/iommu

Reply via email to