Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754904AbbGSTQv (ORCPT ); Sun, 19 Jul 2015 15:16:51 -0400 Received: from mail.linuxfoundation.org ([140.211.169.12]:38665 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932722AbbGSTLo (ORCPT ); Sun, 19 Jul 2015 15:11:44 -0400 From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Dave Martin , Catalin Marinas Subject: [PATCH 4.0 29/58] arm64: mm: Fix freeing of the wrong memmap entries with !SPARSEMEM_VMEMMAP Date: Sun, 19 Jul 2015 12:11:07 -0700 Message-Id: <20150719190812.278200080@linuxfoundation.org> X-Mailer: git-send-email 2.4.6 In-Reply-To: <20150719190811.308546345@linuxfoundation.org> References: <20150719190811.308546345@linuxfoundation.org> User-Agent: quilt/0.64 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 Content-Length: 2001 Lines: 55 4.0-stable review patch. If anyone has any objections, please let me know. ------------------ From: Dave P Martin commit b9bcc919931611498e856eae9bf66337330d04cc upstream. The memmap freeing code in free_unused_memmap() computes the end of each memblock by adding the memblock size onto the base. However, if SPARSEMEM is enabled then the value (start) used for the base may already have been rounded downwards to work out which memmap entries to free after the previous memblock. This may cause memmap entries that are in use to get freed. In general, you're not likely to hit this problem unless there are at least 2 memblocks and one of them is not aligned to a sparsemem section boundary. Note that carve-outs can increase the number of memblocks by splitting the regions listed in the device tree. This problem doesn't occur with SPARSEMEM_VMEMMAP, because the vmemmap code deals with freeing the unused regions of the memmap instead of requiring the arch code to do it. This patch gets the memblock base out of the memblock directly when computing the block end address to ensure the correct value is used. Signed-off-by: Dave Martin Signed-off-by: Catalin Marinas Signed-off-by: Greg Kroah-Hartman --- arch/arm64/mm/init.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) --- a/arch/arm64/mm/init.c +++ b/arch/arm64/mm/init.c @@ -260,7 +260,7 @@ static void __init free_unused_memmap(vo * memmap entries are valid from the bank end aligned to * MAX_ORDER_NR_PAGES. */ - prev_end = ALIGN(start + __phys_to_pfn(reg->size), + prev_end = ALIGN(__phys_to_pfn(reg->base + reg->size), MAX_ORDER_NR_PAGES); } -- 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/