Quoting Chris Wilson (2020-08-22 17:02:09)
Beware that the address size for x86-32 may exceed unsigned long.
[ 0.368971] UBSAN: shift-out-of-bounds in drivers/iommu/intel/iommu.c:128:14 [ 0.369055] shift exponent 36 is too large for 32-bit type 'long unsigned int'
If we don't handle the wide addresses, the pages are mismapped and the device read/writes go astray, detected as DMAR faults and leading to device failure. The behaviour changed (from working to broken) in commit fa954e683178 ("iommu/vt-d: Delegate the dma domain to upper layer"), but the error looks older.
Fixes: fa954e683178 ("iommu/vt-d: Delegate the dma domain to upper layer") Signed-off-by: Chris Wilson chris@chris-wilson.co.uk Cc: James Sewart jamessewart@arista.com Cc: Lu Baolu baolu.lu@linux.intel.com Cc: Joerg Roedel jroedel@suse.de Cc: stable@vger.kernel.org # v5.3+
drivers/iommu/intel/iommu.c | 14 +++++++------- 1 file changed, 7 insertions(+), 7 deletions(-)
diff --git a/drivers/iommu/intel/iommu.c b/drivers/iommu/intel/iommu.c index 2e9c8c3d0da4..ba78a2e854f9 100644 --- a/drivers/iommu/intel/iommu.c +++ b/drivers/iommu/intel/iommu.c @@ -123,29 +123,29 @@ static inline unsigned int level_to_offset_bits(int level) return (level - 1) * LEVEL_STRIDE; } -static inline int pfn_level_offset(unsigned long pfn, int level) +static inline int pfn_level_offset(u64 pfn, int level)
Maybe s/u64/dma_addr_t/ ? I'm not sure what is the appropriate type, just that this makes i915 not try and eat itself. :) -Chris