Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753357Ab2JFHpS (ORCPT ); Sat, 6 Oct 2012 03:45:18 -0400 Received: from rcsinet15.oracle.com ([148.87.113.117]:36723 "EHLO rcsinet15.oracle.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752895Ab2JFHpO (ORCPT ); Sat, 6 Oct 2012 03:45:14 -0400 From: Yinghai Lu To: Thomas Gleixner , Ingo Molnar , "H. Peter Anvin" , Jacob Shin , Tejun Heo Cc: Stefano Stabellini , linux-kernel@vger.kernel.org, Yinghai Lu Subject: [PATCH 2/3] x86, mm: Don't clear page table if next range is ram Date: Sat, 6 Oct 2012 00:44:28 -0700 Message-Id: <1349509469-11475-3-git-send-email-yinghai@kernel.org> X-Mailer: git-send-email 1.7.7 In-Reply-To: <1349509469-11475-1-git-send-email-yinghai@kernel.org> References: <1349509469-11475-1-git-send-email-yinghai@kernel.org> X-Source-IP: ucsinet22.oracle.com [156.151.31.94] Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2876 Lines: 100 During adding code from BRK to map buffer for final page table, It should be safe to remove early_memmap for page table accessing. But get panic after that. It turns out we clear the initial page table wrongly for next range that is separated by holes. And it only happens when we are trying to map range one by one range. After checking before clearing the related page table to fix the problem. Signed-off-by: Yinghai Lu --- arch/x86/mm/init_64.c | 39 +++++++++++++++++++-------------------- 1 files changed, 19 insertions(+), 20 deletions(-) diff --git a/arch/x86/mm/init_64.c b/arch/x86/mm/init_64.c index 5375cf0..0348a02 100644 --- a/arch/x86/mm/init_64.c +++ b/arch/x86/mm/init_64.c @@ -367,20 +367,21 @@ static unsigned long __meminit phys_pte_init(pte_t *pte_page, unsigned long addr, unsigned long end, pgprot_t prot) { - unsigned pages = 0; + unsigned long pages = 0, next; unsigned long last_map_addr = end; int i; pte_t *pte = pte_page + pte_index(addr); - for(i = pte_index(addr); i < PTRS_PER_PTE; i++, addr += PAGE_SIZE, pte++) { + for (i = pte_index(addr); i < PTRS_PER_PTE; i++, addr = next, pte++) { + next = (addr & PAGE_MASK) + PAGE_SIZE; if (addr >= end) { - if (!after_bootmem) { - for(; i < PTRS_PER_PTE; i++, pte++) - set_pte(pte, __pte(0)); - } - break; + if (!after_bootmem && + addr < (2UL<<30) && + !e820_any_mapped(addr & PAGE_MASK, next, 0)) + set_pte(pte, __pte(0)); + continue; } /* @@ -422,16 +423,15 @@ phys_pmd_init(pmd_t *pmd_page, unsigned long address, unsigned long end, pte_t *pte; pgprot_t new_prot = prot; + next = (address & PMD_MASK) + PMD_SIZE; if (address >= end) { - if (!after_bootmem) { - for (; i < PTRS_PER_PMD; i++, pmd++) - set_pmd(pmd, __pmd(0)); - } - break; + if (!after_bootmem && + address < (2UL<<30) && + !e820_any_mapped(address & PMD_MASK, next, 0)) + set_pmd(pmd, __pmd(0)); + continue; } - next = (address & PMD_MASK) + PMD_SIZE; - if (pmd_val(*pmd)) { if (!pmd_large(*pmd)) { spin_lock(&init_mm.page_table_lock); @@ -498,13 +498,12 @@ phys_pud_init(pud_t *pud_page, unsigned long addr, unsigned long end, pmd_t *pmd; pgprot_t prot = PAGE_KERNEL; - if (addr >= end) - break; - next = (addr & PUD_MASK) + PUD_SIZE; - - if (!after_bootmem && !e820_any_mapped(addr, next, 0)) { - set_pud(pud, __pud(0)); + if (addr >= end) { + if (!after_bootmem && + addr < (2UL<<30) && + !e820_any_mapped(addr & PUD_MASK, next, 0)) + set_pud(pud, __pud(0)); continue; } -- 1.7.7 -- 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/