From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753483Ab3LCC3N (ORCPT ); Mon, 2 Dec 2013 21:29:13 -0500 Received: from arroyo.ext.ti.com ([192.94.94.40]:36894 "EHLO arroyo.ext.ti.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753408Ab3LCC3L (ORCPT ); Mon, 2 Dec 2013 21:29:11 -0500 From: Santosh Shilimkar To: CC: , , Grygorii Strashko , Yinghai Lu , Tejun Heo , Andrew Morton , Santosh Shilimkar Subject: [PATCH v2 02/23] mm/memblock: debug: don't free reserved array if !ARCH_DISCARD_MEMBLOCK Date: Mon, 2 Dec 2013 21:27:17 -0500 Message-ID: <1386037658-3161-3-git-send-email-santosh.shilimkar@ti.com> X-Mailer: git-send-email 1.7.9.5 In-Reply-To: <1386037658-3161-1-git-send-email-santosh.shilimkar@ti.com> References: <1386037658-3161-1-git-send-email-santosh.shilimkar@ti.com> MIME-Version: 1.0 Content-Type: text/plain Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Grygorii Strashko Now the Nobootmem allocator will always try to free memory allocated for reserved memory regions (free_low_memory_core_early()) without taking into to account current memblock debugging configuration (CONFIG_ARCH_DISCARD_MEMBLOCK and CONFIG_DEBUG_FS state). As result if: - CONFIG_DEBUG_FS defined - CONFIG_ARCH_DISCARD_MEMBLOCK not defined; - reserved memory regions array have been resized during boot then: - memory allocated for reserved memory regions array will be freed to buddy allocator; - debug_fs entry "sys/kernel/debug/memblock/reserved" will show garbage instead of state of memory reservations. like: 0: 0x98393bc0..0x9a393bbf 1: 0xff120000..0xff11ffff 2: 0x00000000..0xffffffff Hence, do not free memory allocated for reserved memory regions if defined(CONFIG_DEBUG_FS) && !defined(CONFIG_ARCH_DISCARD_MEMBLOCK). Cc: Yinghai Lu Cc: Tejun Heo Cc: Andrew Morton Signed-off-by: Grygorii Strashko Signed-off-by: Santosh Shilimkar --- mm/memblock.c | 13 +++++++++++++ 1 file changed, 13 insertions(+) diff --git a/mm/memblock.c b/mm/memblock.c index aab5669..53da534 100644 --- a/mm/memblock.c +++ b/mm/memblock.c @@ -265,6 +265,19 @@ phys_addr_t __init_memblock get_allocated_memblock_reserved_regions_info( if (memblock.reserved.regions == memblock_reserved_init_regions) return 0; + /* + * Don't allow Nobootmem allocator to free reserved memory regions + * array if + * - CONFIG_DEBUG_FS is enabled; + * - CONFIG_ARCH_DISCARD_MEMBLOCK is not enabled; + * - reserved memory regions array have been resized during boot. + * Otherwise debug_fs entry "sys/kernel/debug/memblock/reserved" + * will show garbage instead of state of memory reservations. + */ + if (IS_ENABLED(CONFIG_DEBUG_FS) && + !IS_ENABLED(CONFIG_ARCH_DISCARD_MEMBLOCK)) + return 0; + *addr = __pa(memblock.reserved.regions); return PAGE_ALIGN(sizeof(struct memblock_region) * -- 1.7.9.5