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From: tip-bot for Yinghai Lu <yinghai@kernel.org>
To: linux-tip-commits@vger.kernel.org
Cc: linux-kernel@vger.kernel.org, hpa@zytor.com, mingo@kernel.org,
	yinghai@kernel.org, tglx@linutronix.de, hpa@linux.intel.com
Subject: [tip:x86/mm2] x86, mm: Add check before clear pte above max_low_pfn on 32bit
Date: Wed, 21 Nov 2012 18:13:02 -0800
Message-ID: <tip-11ed9e927d573d78beda6e6a166612666ae97064@git.kernel.org> (raw)
In-Reply-To: <1353123563-3103-35-git-send-email-yinghai@kernel.org>

Commit-ID:  11ed9e927d573d78beda6e6a166612666ae97064
Gitweb:     http://git.kernel.org/tip/11ed9e927d573d78beda6e6a166612666ae97064
Author:     Yinghai Lu <yinghai@kernel.org>
AuthorDate: Fri, 16 Nov 2012 19:39:11 -0800
Committer:  H. Peter Anvin <hpa@linux.intel.com>
CommitDate: Sat, 17 Nov 2012 11:59:39 -0800

x86, mm: Add check before clear pte above max_low_pfn on 32bit

During test patch that adjust page_size_mask to map small range ram with
big page size, found page table is setup wrongly for 32bit. And
native_pagetable_init wrong clear pte for pmd with large page support.

1. add more comments about why we are expecting pte.

2. add BUG checking, so next time we could find problem earlier
   when we mess up page table setup again.

3. max_low_pfn is not included boundary for low memory mapping.
   We should check from max_low_pfn instead of +1.

4. add print out when some pte really get cleared, or we should use
   WARN() to find out why above max_low_pfn get mapped? so we could
   fix it.

Signed-off-by: Yinghai Lu <yinghai@kernel.org>
Link: http://lkml.kernel.org/r/1353123563-3103-35-git-send-email-yinghai@kernel.org
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
---
 arch/x86/mm/init_32.c | 18 ++++++++++++++++--
 1 file changed, 16 insertions(+), 2 deletions(-)

diff --git a/arch/x86/mm/init_32.c b/arch/x86/mm/init_32.c
index 322ee56..19ef9f0 100644
--- a/arch/x86/mm/init_32.c
+++ b/arch/x86/mm/init_32.c
@@ -480,9 +480,14 @@ void __init native_pagetable_init(void)
 
 	/*
 	 * Remove any mappings which extend past the end of physical
-	 * memory from the boot time page table:
+	 * memory from the boot time page table.
+	 * In virtual address space, we should have at least two pages
+	 * from VMALLOC_END to pkmap or fixmap according to VMALLOC_END
+	 * definition. And max_low_pfn is set to VMALLOC_END physical
+	 * address. If initial memory mapping is doing right job, we
+	 * should have pte used near max_low_pfn or one pmd is not present.
 	 */
-	for (pfn = max_low_pfn + 1; pfn < 1<<(32-PAGE_SHIFT); pfn++) {
+	for (pfn = max_low_pfn; pfn < 1<<(32-PAGE_SHIFT); pfn++) {
 		va = PAGE_OFFSET + (pfn<<PAGE_SHIFT);
 		pgd = base + pgd_index(va);
 		if (!pgd_present(*pgd))
@@ -493,10 +498,19 @@ void __init native_pagetable_init(void)
 		if (!pmd_present(*pmd))
 			break;
 
+		/* should not be large page here */
+		if (pmd_large(*pmd)) {
+			pr_warn("try to clear pte for ram above max_low_pfn: pfn: %lx pmd: %p pmd phys: %lx, but pmd is big page and is not using pte !\n",
+				pfn, pmd, __pa(pmd));
+			BUG_ON(1);
+		}
+
 		pte = pte_offset_kernel(pmd, va);
 		if (!pte_present(*pte))
 			break;
 
+		printk(KERN_DEBUG "clearing pte for ram above max_low_pfn: pfn: %lx pmd: %p pmd phys: %lx pte: %p pte phys: %lx\n",
+				pfn, pmd, __pa(pmd), pte, __pa(pte));
 		pte_clear(NULL, va, pte);
 	}
 	paravirt_alloc_pmd(&init_mm, __pa(base) >> PAGE_SHIFT);

  reply index

Thread overview: 119+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2012-11-17  3:38 [PATCH v8 00/46] x86, mm: map ram from top-down with BRK and memblock Yinghai Lu
2012-11-17  3:38 ` [PATCH v8 01/46] x86, mm: Add global page_size_mask and probe one time only Yinghai Lu
2012-11-22  1:38   ` [tip:x86/mm2] " tip-bot for Yinghai Lu
2012-11-17  3:38 ` [PATCH v8 02/46] x86, mm: Split out split_mem_range from init_memory_mapping Yinghai Lu
2012-11-22  1:39   ` [tip:x86/mm2] " tip-bot for Yinghai Lu
2012-11-17  3:38 ` [PATCH v8 03/46] x86, mm: Move down find_early_table_space() Yinghai Lu
2012-11-22  1:40   ` [tip:x86/mm2] " tip-bot for Yinghai Lu
2012-11-28 16:50   ` [PATCH v8 03/46] " Konrad Rzeszutek Wilk
2012-11-17  3:38 ` [PATCH v8 04/46] x86, mm: Move init_memory_mapping calling out of setup.c Yinghai Lu
2012-11-22  1:41   ` [tip:x86/mm2] " tip-bot for Yinghai Lu
2012-11-28 16:50   ` [PATCH v8 04/46] " Konrad Rzeszutek Wilk
2012-11-17  3:38 ` [PATCH v8 05/46] x86, mm: Revert back good_end setting for 64bit Yinghai Lu
2012-11-22  1:42   ` [tip:x86/mm2] " tip-bot for Yinghai Lu
2012-11-17  3:38 ` [PATCH v8 06/46] x86, mm: Change find_early_table_space() paramters Yinghai Lu
2012-11-22  1:43   ` [tip:x86/mm2] " tip-bot for Yinghai Lu
2012-11-28 16:50   ` [PATCH v8 06/46] " Konrad Rzeszutek Wilk
2012-11-17  3:38 ` [PATCH v8 07/46] x86, mm: Find early page table buffer together Yinghai Lu
2012-11-22  1:44   ` [tip:x86/mm2] " tip-bot for Yinghai Lu
2012-11-28 16:50   ` [PATCH v8 07/46] " Konrad Rzeszutek Wilk
2012-11-17  3:38 ` [PATCH v8 08/46] x86, mm: Separate out calculate_table_space_size() Yinghai Lu
2012-11-22  1:45   ` [tip:x86/mm2] " tip-bot for Yinghai Lu
2012-11-28 16:59   ` [PATCH v8 08/46] " Konrad Rzeszutek Wilk
2012-11-17  3:38 ` [PATCH v8 09/46] x86, mm: Set memblock initial limit to 1M Yinghai Lu
2012-11-22  1:46   ` [tip:x86/mm2] " tip-bot for Yinghai Lu
2012-11-17  3:38 ` [PATCH v8 10/46] x86, mm: if kernel .text .data .bss are not marked as E820_RAM, complain and fix Yinghai Lu
2012-11-22  1:47   ` [tip:x86/mm2] " tip-bot for Jacob Shin
2012-11-17  3:38 ` [PATCH v8 11/46] x86, mm: Fixup code testing if a pfn is direct mapped Yinghai Lu
2012-11-22  1:48   ` [tip:x86/mm2] " tip-bot for Jacob Shin
2012-11-17  3:38 ` [PATCH v8 12/46] x86, mm: use pfn_range_is_mapped() with CPA Yinghai Lu
2012-11-22  1:49   ` [tip:x86/mm2] " tip-bot for Yinghai Lu
2012-11-28 17:06   ` [PATCH v8 12/46] " Konrad Rzeszutek Wilk
2012-11-28 19:33     ` Yinghai Lu
2012-11-17  3:38 ` [PATCH v8 13/46] x86, mm: use pfn_range_is_mapped() with gart Yinghai Lu
2012-11-22  1:50   ` [tip:x86/mm2] " tip-bot for Yinghai Lu
2012-11-28 17:07   ` [PATCH v8 13/46] " Konrad Rzeszutek Wilk
2012-11-17  3:38 ` [PATCH v8 14/46] x86, mm: use pfn_range_is_mapped() with reserve_initrd Yinghai Lu
2012-11-22  1:51   ` [tip:x86/mm2] " tip-bot for Yinghai Lu
2012-11-28 17:08   ` [PATCH v8 14/46] " Konrad Rzeszutek Wilk
2012-11-28 19:40     ` Yinghai Lu
2012-11-17  3:38 ` [PATCH v8 15/46] x86, mm: Only direct map addresses that are marked as E820_RAM Yinghai Lu
2012-11-22  1:53   ` [tip:x86/mm2] " tip-bot for Jacob Shin
2012-11-28 17:15   ` [PATCH v8 15/46] " Konrad Rzeszutek Wilk
2012-11-28 19:43     ` Yinghai Lu
2012-11-17  3:38 ` [PATCH v8 16/46] x86, mm: relocate initrd under all mem for 64bit Yinghai Lu
2012-11-22  1:54   ` [tip:x86/mm2] " tip-bot for Yinghai Lu
2012-11-17  3:38 ` [PATCH v8 17/46] x86, mm: Align start address to correct big page size Yinghai Lu
2012-11-22  1:55   ` [tip:x86/mm2] " tip-bot for Yinghai Lu
2012-11-17  3:38 ` [PATCH v8 18/46] x86, mm: Use big page size for small memory range Yinghai Lu
2012-11-22  1:56   ` [tip:x86/mm2] " tip-bot for Yinghai Lu
2012-11-17  3:38 ` [PATCH v8 19/46] x86, mm: Don't clear page table if range is ram Yinghai Lu
2012-11-22  1:57   ` [tip:x86/mm2] " tip-bot for Yinghai Lu
2012-11-17  3:38 ` [PATCH v8 20/46] x86, mm: Break down init_all_memory_mapping Yinghai Lu
2012-11-22  1:58   ` [tip:x86/mm2] " tip-bot for Yinghai Lu
2012-11-17  3:38 ` [PATCH v8 21/46] x86, mm: setup page table in top-down Yinghai Lu
2012-11-22  1:59   ` [tip:x86/mm2] " tip-bot for Yinghai Lu
2012-11-28 17:50   ` [PATCH v8 21/46] " Konrad Rzeszutek Wilk
2012-11-28 20:16     ` Yinghai Lu
2012-12-05 21:53       ` Konrad Rzeszutek Wilk
2012-11-17  3:38 ` [PATCH v8 22/46] x86, mm: Remove early_memremap workaround for page table accessing on 64bit Yinghai Lu
2012-11-22  2:00   ` [tip:x86/mm2] " tip-bot for Yinghai Lu
2012-11-28 18:57   ` [PATCH v8 22/46] " Konrad Rzeszutek Wilk
2012-11-17  3:39 ` [PATCH v8 23/46] x86, mm: Remove parameter in alloc_low_page for 64bit Yinghai Lu
2012-11-22  2:01   ` [tip:x86/mm2] " tip-bot for Yinghai Lu
2012-11-28 18:57   ` [PATCH v8 23/46] " Konrad Rzeszutek Wilk
2012-11-17  3:39 ` [PATCH v8 24/46] x86, mm: Merge alloc_low_page between 64bit and 32bit Yinghai Lu
2012-11-22  2:02   ` [tip:x86/mm2] " tip-bot for Yinghai Lu
2012-11-17  3:39 ` [PATCH v8 25/46] x86, mm: Move min_pfn_mapped back to mm/init.c Yinghai Lu
2012-11-22  2:03   ` [tip:x86/mm2] " tip-bot for Yinghai Lu
2012-11-17  3:39 ` [PATCH v8 26/46] x86, mm, Xen: Remove mapping_pagetable_reserve() Yinghai Lu
2012-11-22  2:04   ` [tip:x86/mm2] " tip-bot for Yinghai Lu
2012-11-17  3:39 ` [PATCH v8 27/46] x86, mm: Add alloc_low_pages(num) Yinghai Lu
2012-11-22  2:05   ` [tip:x86/mm2] " tip-bot for Yinghai Lu
2012-11-17  3:39 ` [PATCH v8 28/46] x86, mm: Add pointer about Xen mmu requirement for alloc_low_pages Yinghai Lu
2012-11-22  2:06   ` [tip:x86/mm2] " tip-bot for Stefano Stabellini
2012-11-17  3:39 ` [PATCH v8 29/46] x86, mm: only call early_ioremap_page_table_range_init() once Yinghai Lu
2012-11-22  2:07   ` [tip:x86/mm2] " tip-bot for Yinghai Lu
2012-11-28 19:02   ` [PATCH v8 29/46] " Konrad Rzeszutek Wilk
2012-11-17  3:39 ` [PATCH v8 30/46] x86, mm: Move back pgt_buf_* to mm/init.c Yinghai Lu
2012-11-22  2:08   ` [tip:x86/mm2] " tip-bot for Yinghai Lu
2012-11-17  3:39 ` [PATCH v8 31/46] x86, mm: Move init_gbpages() out of setup.c Yinghai Lu
2012-11-22  2:09   ` [tip:x86/mm2] " tip-bot for Yinghai Lu
2012-11-17  3:39 ` [PATCH v8 32/46] x86, mm: change low/hignmem_pfn_init to static on 32bit Yinghai Lu
2012-11-22  2:10   ` [tip:x86/mm2] x86, mm: change low/ hignmem_pfn_init " tip-bot for Yinghai Lu
2012-11-17  3:39 ` [PATCH v8 33/46] x86, mm: Move function declaration into mm_internal.h Yinghai Lu
2012-11-22  2:11   ` [tip:x86/mm2] " tip-bot for Yinghai Lu
2012-11-17  3:39 ` [PATCH v8 34/46] x86, mm: Add check before clear pte above max_low_pfn on 32bit Yinghai Lu
2012-11-22  2:13   ` tip-bot for Yinghai Lu [this message]
2012-11-28 19:09   ` Konrad Rzeszutek Wilk
2012-11-28 20:38     ` Yinghai Lu
2012-11-17  3:39 ` [PATCH v8 35/46] x86, mm: use round_up/down in split_mem_range() Yinghai Lu
2012-11-22  2:14   ` [tip:x86/mm2] " tip-bot for Yinghai Lu
2012-11-17  3:39 ` [PATCH v8 36/46] x86, mm: use PFN_DOWN " Yinghai Lu
2012-11-22  2:15   ` [tip:x86/mm2] " tip-bot for Yinghai Lu
2012-11-17  3:39 ` [PATCH v8 37/46] x86, mm: use pfn instead of pos in split_mem_range Yinghai Lu
2012-11-22  2:16   ` [tip:x86/mm2] " tip-bot for Yinghai Lu
2012-11-17  3:39 ` [PATCH v8 38/46] x86, mm: use limit_pfn for end pfn Yinghai Lu
2012-11-22  2:17   ` [tip:x86/mm2] " tip-bot for Yinghai Lu
2012-11-17  3:39 ` [PATCH v8 39/46] x86, mm: Unifying after_bootmem for 32bit and 64bit Yinghai Lu
2012-11-22  2:18   ` [tip:x86/mm2] " tip-bot for Yinghai Lu
2012-11-17  3:39 ` [PATCH v8 40/46] x86, mm: Move after_bootmem to mm_internel.h Yinghai Lu
2012-11-22  2:19   ` [tip:x86/mm2] " tip-bot for Yinghai Lu
2012-11-17  3:39 ` [PATCH v8 41/46] x86, mm: Use clamp_t() in init_range_memory_mapping Yinghai Lu
2012-11-22  2:20   ` [tip:x86/mm2] " tip-bot for Yinghai Lu
2012-11-17  3:39 ` [PATCH v8 42/46] x86, mm: kill numa_free_all_bootmem() Yinghai Lu
2012-11-22  2:21   ` [tip:x86/mm2] " tip-bot for Yinghai Lu
2012-11-17  3:39 ` [PATCH v8 43/46] x86, mm: kill numa_64.h Yinghai Lu
2012-11-22  2:22   ` [tip:x86/mm2] " tip-bot for Yinghai Lu
2012-11-17  3:39 ` [PATCH v8 44/46] sparc, mm: Remove calling of free_all_bootmem_node() Yinghai Lu
2012-11-22  2:23   ` [tip:x86/mm2] sparc, mm: Remove calling of free_all_bootmem_node( ) tip-bot for Yinghai Lu
2012-11-17  3:39 ` [PATCH v8 45/46] mm: Kill NO_BOOTMEM version free_all_bootmem_node() Yinghai Lu
2012-11-22  2:24   ` [tip:x86/mm2] " tip-bot for Yinghai Lu
2012-11-17  3:39 ` [PATCH v8 46/46] x86, mm: Let "memmap=" take more entries one time Yinghai Lu
2012-11-22  2:25   ` [tip:x86/mm2] " tip-bot for Yinghai Lu
2012-11-28 19:12   ` [PATCH v8 46/46] " Konrad Rzeszutek Wilk
2012-11-27 21:17 ` [PATCH v8 00/46] x86, mm: map ram from top-down with BRK and memblock Konrad Rzeszutek Wilk
2012-11-28 19:35   ` Konrad Rzeszutek Wilk
2012-11-28 19:47     ` Yinghai Lu
2012-11-28 20:57       ` Konrad Rzeszutek Wilk
2012-11-28 21:06         ` Yinghai Lu

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