Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932507Ab3D2WjK (ORCPT ); Mon, 29 Apr 2013 18:39:10 -0400 Received: from g5t0006.atlanta.hp.com ([15.192.0.43]:2340 "EHLO g5t0006.atlanta.hp.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932227Ab3D2WjG (ORCPT ); Mon, 29 Apr 2013 18:39:06 -0400 From: Jerry Hoemann To: tglx@linutronix.de, mingo@redhat.com, hpa@zytor.com Cc: x86@kernel.org, jacob.shin@amd.com, gregkh@linuxfoundation.org, yinghai@kernel.org, linux-kernel@vger.kernel.org, Jerry Hoemann Subject: [PATCH] x86/mm: account for PGDIR_SIZE alignment Date: Mon, 29 Apr 2013 16:38:49 -0600 Message-Id: <1367275129-22383-1-git-send-email-jerry.hoemann@hp.com> X-Mailer: git-send-email 1.8.1.4 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2046 Lines: 57 Patch for 3.0-stable. Function find_early_table_space removed upstream. Fixes panic in alloc_low_page due to pgt_buf overflow during init_memory_mapping. find_early_table_space sizes pgt_buf based upon the size of the memory being mapped, but it does not take into account the alignment of the memory. When the region being mapped spans a 512GB (PGDIR_SIZE) alignment, a panic from alloc_low_pages occurs. kernel_physical_mapping_init takes into account PGDIR_SIZE alignment. This causes an extra call to alloc_low_page to be made. This extra call isn't accounted for by find_early_table_space and causes a kernel panic. Change is to take into account PGDIR_SIZE alignment in find_early_table_space. Signed-off-by: Jerry Hoemann --- arch/x86/mm/init.c | 5 +++++ 1 file changed, 5 insertions(+) diff --git a/arch/x86/mm/init.c b/arch/x86/mm/init.c index c22c423..96c4577 100644 --- a/arch/x86/mm/init.c +++ b/arch/x86/mm/init.c @@ -44,11 +44,15 @@ static void __init find_early_table_space(struct map_range *mr, int nr_range) int i; unsigned long puds = 0, pmds = 0, ptes = 0, tables; unsigned long start = 0, good_end; + unsigned long pgd_extra = 0; phys_addr_t base; for (i = 0; i < nr_range; i++) { unsigned long range, extra; + if ((mr[i].end >> PGDIR_SHIFT) - (mr[i].start >> PGDIR_SHIFT)) + pgd_extra++; + range = mr[i].end - mr[i].start; puds += (range + PUD_SIZE - 1) >> PUD_SHIFT; @@ -73,6 +77,7 @@ static void __init find_early_table_space(struct map_range *mr, int nr_range) tables = roundup(puds * sizeof(pud_t), PAGE_SIZE); tables += roundup(pmds * sizeof(pmd_t), PAGE_SIZE); tables += roundup(ptes * sizeof(pte_t), PAGE_SIZE); + tables += (pgd_extra * PAGE_SIZE); #ifdef CONFIG_X86_32 /* for fixmap */ -- 1.8.1.4 -- 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/