Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754996AbaJ1DlD (ORCPT ); Mon, 27 Oct 2014 23:41:03 -0400 Received: from mail.linuxfoundation.org ([140.211.169.12]:44891 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754975AbaJ1DlA (ORCPT ); Mon, 27 Oct 2014 23:41:00 -0400 From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Weijie Yang , Michal Nazarewicz , Joonsoo Kim , "Aneesh Kumar K.V" , Andrew Morton , Linus Torvalds Subject: [PATCH 3.17 108/146] mm/cma: fix cma bitmap aligned mask computing Date: Tue, 28 Oct 2014 11:34:10 +0800 Message-Id: <20141028033348.134575468@linuxfoundation.org> X-Mailer: git-send-email 2.1.2 In-Reply-To: <20141028033343.441992423@linuxfoundation.org> References: <20141028033343.441992423@linuxfoundation.org> User-Agent: quilt/0.63-1 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 3.17-stable review patch. If anyone has any objections, please let me know. ------------------ From: Weijie Yang 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. [akpm@linux-foundation.org: coding-style fixes] Signed-off-by: Weijie Yang Acked-by: Michal Nazarewicz Cc: Joonsoo Kim Cc: "Aneesh Kumar K.V" Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds Signed-off-by: Greg Kroah-Hartman --- 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 majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/