From: Frank van der Linden <fvdl@xxxxxxxxxx> commit b174f139bdc8aaaf72f5b67ad1bd512c4868a87e upstream. cma_init_reserved_mem uses IS_ALIGNED to check if the size represented by one bit in the cma allocation bitmask is aligned with CMA_MIN_ALIGNMENT_BYTES (pageblock size). However, this is too strict, as this will fail if order_per_bit > pageblock_order, which is a valid configuration. We could check IS_ALIGNED both ways, but since both numbers are powers of two, no check is needed at all. Link: https://lkml.kernel.org/r/20240404162515.527802-1-fvdl@xxxxxxxxxx Fixes: de9e14eebf33 ("drivers: dma-contiguous: add initialization from device tree") Signed-off-by: Frank van der Linden <fvdl@xxxxxxxxxx> Acked-by: David Hildenbrand <david@xxxxxxxxxx> Cc: Marek Szyprowski <m.szyprowski@xxxxxxxxxxx> Cc: Muchun Song <muchun.song@xxxxxxxxx> Cc: Roman Gushchin <roman.gushchin@xxxxxxxxx> Cc: <stable@xxxxxxxxxxxxxxx> Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- mm/cma.c | 4 ---- 1 file changed, 4 deletions(-) --- a/mm/cma.c +++ b/mm/cma.c @@ -186,10 +186,6 @@ int __init cma_init_reserved_mem(phys_ad if (!size || !memblock_is_region_reserved(base, size)) return -EINVAL; - /* alignment should be aligned with order_per_bit */ - if (!IS_ALIGNED(CMA_MIN_ALIGNMENT_PAGES, 1 << order_per_bit)) - return -EINVAL; - /* ensure minimal alignment required by mm core */ if (!IS_ALIGNED(base | size, CMA_MIN_ALIGNMENT_BYTES)) return -EINVAL; Patches currently in stable-queue which might be from fvdl@xxxxxxxxxx are queue-6.1/mm-hugetlb-pass-correct-order_per_bit-to-cma_declare_contiguous_nid.patch queue-6.1/mm-cma-drop-incorrect-alignment-check-in-cma_init_reserved_mem.patch
