5.15-stable review patch. If anyone has any objections, please let me know.
------------------
From: Frank van der Linden fvdl@google.com
[ Upstream commit b174f139bdc8aaaf72f5b67ad1bd512c4868a87e ]
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@google.com Fixes: de9e14eebf33 ("drivers: dma-contiguous: add initialization from device tree") Signed-off-by: Frank van der Linden fvdl@google.com Acked-by: David Hildenbrand david@redhat.com Cc: Marek Szyprowski m.szyprowski@samsung.com Cc: Muchun Song muchun.song@linux.dev Cc: Roman Gushchin roman.gushchin@linux.dev Cc: stable@vger.kernel.org Signed-off-by: Andrew Morton akpm@linux-foundation.org Signed-off-by: Sasha Levin sashal@kernel.org --- mm/cma.c | 4 ---- 1 file changed, 4 deletions(-)
diff --git a/mm/cma.c b/mm/cma.c index 5208aee4f45ad..88fbd4f8124d3 100644 --- a/mm/cma.c +++ b/mm/cma.c @@ -179,10 +179,6 @@ int __init cma_init_reserved_mem(phys_addr_t base, phys_addr_t size, 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;