swiotlb: Enforce page alignment in swiotlb_alloc()

When allocating pages from a restricted DMA pool in swiotlb_alloc(),
the buffer address is blindly converted to a 'struct page *' that is
returned to the caller. In the unlikely event of an allocation bug,
page-unaligned addresses are not detected and slots can silently be
double-allocated.

Add a simple check of the buffer alignment in swiotlb_alloc() to make
debugging a little easier if something has gone wonky.

Signed-off-by: Will Deacon <[email protected]>
Reviewed-by: Michael Kelley <[email protected]>
Reviewed-by: Petr Tesarik <[email protected]>
Tested-by: Nicolin Chen <[email protected]>
Tested-by: Michael Kelley <[email protected]>
Signed-off-by: Christoph Hellwig <[email protected]>

0 files changed, 0 insertions, 0 deletions