The patch titled Subject: mm/cma: fix cma bitmap aligned mask computing has been added to the -mm tree. Its filename is mm-cma-fix-cma-bitmap-aligned-mask-computing.patch This patch should soon appear at http://ozlabs.org/~akpm/mmots/broken-out/mm-cma-fix-cma-bitmap-aligned-mask-computing.patch and later at http://ozlabs.org/~akpm/mmotm/broken-out/mm-cma-fix-cma-bitmap-aligned-mask-computing.patch Before you just go and hit "reply", please: a) Consider who else should be cc'ed b) Prefer to cc a suitable mailing list as well c) Ideally: find the original patch on the mailing list and do a reply-to-all to that, adding suitable additional cc's *** Remember to use Documentation/SubmitChecklist when testing your code *** The -mm tree is included into linux-next and is updated there every 3-4 working days ------------------------------------------------------ From: Weijie Yang <weijie.yang@xxxxxxxxxxx> Subject: mm/cma: fix cma bitmap aligned mask computing The current cma bitmap aligned mask computation is incorrect. It could cause an unexpected alignment when using cma_alloc() if the wanted align order is larger than cma->order_per_bit. Take kvm for example (PAGE_SHIFT = 12), kvm_cma->order_per_bit is set to 6. When kvm_alloc_rma() tries to alloc kvm_rma_pages, it will use 15 as the expected align value. After using the current implementation however, we get 0 as cma bitmap aligned mask other than 511. This patch fixes the cma bitmap aligned mask calculation. Signed-off-by: Weijie Yang <weijie.yang@xxxxxxxxxxx> Acked-by: Michal Nazarewicz <mina86@xxxxxxxxxx> Cc: Joonsoo Kim <iamjoonsoo.kim@xxxxxxx> Cc: "Aneesh Kumar K.V" <aneesh.kumar@xxxxxxxxxxxxxxxxxx> Cc: <stable@xxxxxxxxxxxxxxx> [3.17] Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> --- mm/cma.c | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-) diff -puN mm/cma.c~mm-cma-fix-cma-bitmap-aligned-mask-computing mm/cma.c --- a/mm/cma.c~mm-cma-fix-cma-bitmap-aligned-mask-computing +++ a/mm/cma.c @@ -58,7 +58,10 @@ unsigned long cma_get_size(struct cma *c static unsigned long cma_bitmap_aligned_mask(struct cma *cma, int align_order) { - return (1UL << (align_order >> cma->order_per_bit)) - 1; + if (align_order <= cma->order_per_bit) + return 0; + else + return (1UL << (align_order - cma->order_per_bit)) - 1; } static unsigned long cma_bitmap_maxno(struct cma *cma) _ Patches currently in -mm which might be from weijie.yang@xxxxxxxxxxx are origin.patch mm-cma-fix-cma-bitmap-aligned-mask-computing.patch -- To unsubscribe from this list: send the line "unsubscribe stable" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html