Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751435AbdFZRX6 (ORCPT ); Mon, 26 Jun 2017 13:23:58 -0400 Received: from mail-wm0-f68.google.com ([74.125.82.68]:34119 "EHLO mail-wm0-f68.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750763AbdFZRXv (ORCPT ); Mon, 26 Jun 2017 13:23:51 -0400 From: Doug Berger To: linux@armlinux.org.uk Cc: labbott@redhat.com, ard.biesheuvel@linaro.org, nicolas.pitre@linaro.org, tixy@linaro.org, f.fainelli@gmail.com, keescook@chromium.org, marc.zyngier@arm.com, linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, Doug Berger Subject: [PATCH] ARM: memblock limit must be pmd-aligned Date: Mon, 26 Jun 2017 10:23:15 -0700 Message-Id: <20170626172315.26369-1-opendmb@gmail.com> X-Mailer: git-send-email 2.13.0 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1268 Lines: 33 There is a path through the adjust_lowmem_bounds() routine where if all memory regions start and end on pmd-aligned addresses the memblock_limit will be set to arm_lowmem_limit. However, since arm_lowmem_limit can be affected by the vmalloc early parameter, the value of arm_lowmem_limit may not be pmd-aligned. This commit corrects this oversight such that memblock_limit is always rounded down to pmd-alignment. The pmd containing arm_lowmem_limit is cleared by prepare_page_table() and without this commit it is possible for early_alloc() to allocate unmapped memory in that range when mapping the lowmem. Signed-off-by: Doug Berger --- arch/arm/mm/mmu.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/arch/arm/mm/mmu.c b/arch/arm/mm/mmu.c index 31af3cb59a60..2ae4f9c9d757 100644 --- a/arch/arm/mm/mmu.c +++ b/arch/arm/mm/mmu.c @@ -1226,7 +1226,7 @@ void __init adjust_lowmem_bounds(void) if (memblock_limit) memblock_limit = round_down(memblock_limit, PMD_SIZE); if (!memblock_limit) - memblock_limit = arm_lowmem_limit; + memblock_limit = round_down(arm_lowmem_limit, PMD_SIZE); if (!IS_ENABLED(CONFIG_HIGHMEM) || cache_is_vipt_aliasing()) { if (memblock_end_of_DRAM() > arm_lowmem_limit) { -- 2.13.0