3.17-stable review patch. If anyone has any objections, please let me know.
------------------ From: Weijie Yang <[email protected]> commit 68faed630fc151a7a1c4853df00fb3dcacf782b4 upstream. 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. [[email protected]: coding-style fixes] Signed-off-by: Weijie Yang <[email protected]> Acked-by: Michal Nazarewicz <[email protected]> Cc: Joonsoo Kim <[email protected]> Cc: "Aneesh Kumar K.V" <[email protected]> Signed-off-by: Andrew Morton <[email protected]> Signed-off-by: Linus Torvalds <[email protected]> Signed-off-by: Greg Kroah-Hartman <[email protected]> --- mm/cma.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) --- a/mm/cma.c +++ b/mm/cma.c @@ -57,7 +57,9 @@ 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; + return (1UL << (align_order - cma->order_per_bit)) - 1; } static unsigned long cma_bitmap_maxno(struct cma *cma) -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
