From 70f1528747651b20c7769d3516ade369f9963237 Mon Sep 17 00:00:00 2001 From: "Kirill A. Shutemov" Date: Mon, 30 Nov 2015 11:10:33 +0100 Subject: [PATCH] x86/mm: Fix regression with huge pages on PAE MIME-Version: 1.0 Content-Type: text/plain; charset=utf8 Content-Transfer-Encoding: 8bit Recent PAT patchset has caused issue on 32-bit PAE machines: page:eea45000 count:0 mapcount:-128 mapping: (null) index:0x0 flags: 0x40000000() page dumped because: VM_BUG_ON_PAGE(page_mapcount(page) < 0) ------------[ cut here ]------------ kernel BUG at /home/build/linux-boris/mm/huge_memory.c:1485! invalid opcode: 0000 [#1] SMP [...] Call Trace: unmap_single_vma ? __wake_up unmap_vmas unmap_region do_munmap vm_munmap SyS_munmap do_fast_syscall_32 ? __do_page_fault sysenter_past_esp Code: ... EIP: [] zap_huge_pmd+0x240/0x260 SS:ESP 0068:f6459d98 The problem is in pmd_pfn_mask() and pmd_flags_mask(). These helpers use PMD_PAGE_MASK to calculate resulting mask. PMD_PAGE_MASK is 'unsigned long', not 'unsigned long long' as phys_addr_t is on 32-bit PAE (ARCH_PHYS_ADDR_T_64BIT). As a result, the upper bits of resulting mask get truncated. pud_pfn_mask() and pud_flags_mask() aren't problematic since we don't have PUD page table level on 32-bit systems, but it's reasonable to keep them consistent with PMD counterpart. Introduce PHYSICAL_PMD_PAGE_MASK and PHYSICAL_PUD_PAGE_MASK in addition to existing PHYSICAL_PAGE_MASK and reworks helpers to use them. Reported-and-Tested-by: Boris Ostrovsky Signed-off-by: Kirill A. Shutemov [ Fix -Woverflow warnings from the realmode code. ] Signed-off-by: Borislav Petkov Reviewed-by: Toshi Kani Cc: Andrew Morton Cc: Andy Lutomirski Cc: Borislav Petkov Cc: Brian Gerst Cc: Denys Vlasenko Cc: H. Peter Anvin Cc: Jürgen Gross Cc: Linus Torvalds Cc: Mel Gorman Cc: Peter Zijlstra Cc: Thomas Gleixner Cc: elliott@hpe.com Cc: konrad.wilk@oracle.com Cc: linux-mm Fixes: f70abb0fc3da ("x86/asm: Fix pud/pmd interfaces to handle large PAT bit") Link: http://lkml.kernel.org/r/1448878233-11390-2-git-send-email-bp@alien8.de Signed-off-by: Ingo Molnar Signed-off-by: Ingo Molnar --- arch/x86/boot/boot.h | 1 - arch/x86/boot/video-mode.c | 2 ++ arch/x86/boot/video.c | 2 ++ arch/x86/include/asm/page_types.h | 16 +++++++++------- arch/x86/include/asm/pgtable_types.h | 14 ++++---------- arch/x86/include/asm/x86_init.h | 1 - 6 files changed, 17 insertions(+), 19 deletions(-) diff --git a/arch/x86/boot/boot.h b/arch/x86/boot/boot.h index 0033e96c3f09..9011a88353de 100644 --- a/arch/x86/boot/boot.h +++ b/arch/x86/boot/boot.h @@ -23,7 +23,6 @@ #include #include #include -#include #include #include "bitops.h" #include "ctype.h" diff --git a/arch/x86/boot/video-mode.c b/arch/x86/boot/video-mode.c index aa8a96b052e3..95c7a818c0ed 100644 --- a/arch/x86/boot/video-mode.c +++ b/arch/x86/boot/video-mode.c @@ -19,6 +19,8 @@ #include "video.h" #include "vesa.h" +#include + /* * Common variables */ diff --git a/arch/x86/boot/video.c b/arch/x86/boot/video.c index 05111bb8d018..77780e386e9b 100644 --- a/arch/x86/boot/video.c +++ b/arch/x86/boot/video.c @@ -13,6 +13,8 @@ * Select video mode */ +#include + #include "boot.h" #include "video.h" #include "vesa.h" diff --git a/arch/x86/include/asm/page_types.h b/arch/x86/include/asm/page_types.h index c5b7fb2774d0..cc071c6f7d4d 100644 --- a/arch/x86/include/asm/page_types.h +++ b/arch/x86/include/asm/page_types.h @@ -9,19 +9,21 @@ #define PAGE_SIZE (_AC(1,UL) << PAGE_SHIFT) #define PAGE_MASK (~(PAGE_SIZE-1)) +#define PMD_PAGE_SIZE (_AC(1, UL) << PMD_SHIFT) +#define PMD_PAGE_MASK (~(PMD_PAGE_SIZE-1)) + +#define PUD_PAGE_SIZE (_AC(1, UL) << PUD_SHIFT) +#define PUD_PAGE_MASK (~(PUD_PAGE_SIZE-1)) + #define __PHYSICAL_MASK ((phys_addr_t)((1ULL << __PHYSICAL_MASK_SHIFT) - 1)) #define __VIRTUAL_MASK ((1UL << __VIRTUAL_MASK_SHIFT) - 1) -/* Cast PAGE_MASK to a signed type so that it is sign-extended if +/* Cast *PAGE_MASK to a signed type so that it is sign-extended if virtual addresses are 32-bits but physical addresses are larger (ie, 32-bit PAE). */ #define PHYSICAL_PAGE_MASK (((signed long)PAGE_MASK) & __PHYSICAL_MASK) - -#define PMD_PAGE_SIZE (_AC(1, UL) << PMD_SHIFT) -#define PMD_PAGE_MASK (~(PMD_PAGE_SIZE-1)) - -#define PUD_PAGE_SIZE (_AC(1, UL) << PUD_SHIFT) -#define PUD_PAGE_MASK (~(PUD_PAGE_SIZE-1)) +#define PHYSICAL_PMD_PAGE_MASK (((signed long)PMD_PAGE_MASK) & __PHYSICAL_MASK) +#define PHYSICAL_PUD_PAGE_MASK (((signed long)PUD_PAGE_MASK) & __PHYSICAL_MASK) #define HPAGE_SHIFT PMD_SHIFT #define HPAGE_SIZE (_AC(1,UL) << HPAGE_SHIFT) diff --git a/arch/x86/include/asm/pgtable_types.h b/arch/x86/include/asm/pgtable_types.h index dd5b0aa9dd2f..a471cadb9630 100644 --- a/arch/x86/include/asm/pgtable_types.h +++ b/arch/x86/include/asm/pgtable_types.h @@ -279,17 +279,14 @@ static inline pmdval_t native_pmd_val(pmd_t pmd) static inline pudval_t pud_pfn_mask(pud_t pud) { if (native_pud_val(pud) & _PAGE_PSE) - return PUD_PAGE_MASK & PHYSICAL_PAGE_MASK; + return PHYSICAL_PUD_PAGE_MASK; else return PTE_PFN_MASK; } static inline pudval_t pud_flags_mask(pud_t pud) { - if (native_pud_val(pud) & _PAGE_PSE) - return ~(PUD_PAGE_MASK & (pudval_t)PHYSICAL_PAGE_MASK); - else - return ~PTE_PFN_MASK; + return ~pud_pfn_mask(pud); } static inline pudval_t pud_flags(pud_t pud) @@ -300,17 +297,14 @@ static inline pudval_t pud_flags(pud_t pud) static inline pmdval_t pmd_pfn_mask(pmd_t pmd) { if (native_pmd_val(pmd) & _PAGE_PSE) - return PMD_PAGE_MASK & PHYSICAL_PAGE_MASK; + return PHYSICAL_PMD_PAGE_MASK; else return PTE_PFN_MASK; } static inline pmdval_t pmd_flags_mask(pmd_t pmd) { - if (native_pmd_val(pmd) & _PAGE_PSE) - return ~(PMD_PAGE_MASK & (pmdval_t)PHYSICAL_PAGE_MASK); - else - return ~PTE_PFN_MASK; + return ~pmd_pfn_mask(pmd); } static inline pmdval_t pmd_flags(pmd_t pmd) diff --git a/arch/x86/include/asm/x86_init.h b/arch/x86/include/asm/x86_init.h index 48d34d28f5a6..cd0fc0cc78bc 100644 --- a/arch/x86/include/asm/x86_init.h +++ b/arch/x86/include/asm/x86_init.h @@ -1,7 +1,6 @@ #ifndef _ASM_X86_PLATFORM_H #define _ASM_X86_PLATFORM_H -#include #include struct mpc_bus; -- 2.20.1