From 2bd3a99c9d1851182f73d0a024dc5bdb0a470e8c Mon Sep 17 00:00:00 2001 From: Jeremy Fitzhardinge Date: Tue, 20 May 2008 08:26:17 +0100 Subject: x86: define PTE_MASK in a universally useful way Define PTE_MASK so that it contains a meaningful value for all x86 pagetable configurations. Previously it was defined as a "long" which means that it was too short to cover a 32-bit PAE pte entry. It is now defined as a pteval_t, which is an integer type long enough to contain a full pte (or pmd, pud, pgd). This fixes an Xorg crash on 32-bit x86 with PAE due to corruption of the NX bit in mprotect due to the incorrect type/value of PTE_MASK reported by Hugh Dickins: "Yes, thanks Jeremy: I've checked that each stage builds and runs X on my boxes here, x86_32 and x86_32+PAE and x86_64. (So even 1/8 is enough to fix the PAT pte_modify issue, though 2/8 then fixes compiler warnings.)" Signed-off-by: Jeremy Fitzhardinge Tested-by: Hugh Dickins Signed-off-by: Linus Torvalds --- include/asm-x86/page.h | 13 +++++++++---- 1 file changed, 9 insertions(+), 4 deletions(-) (limited to 'include/asm-x86/page.h') diff --git a/include/asm-x86/page.h b/include/asm-x86/page.h index b381f4a5a0b..76b35e636d7 100644 --- a/include/asm-x86/page.h +++ b/include/asm-x86/page.h @@ -10,8 +10,13 @@ #ifdef __KERNEL__ -#define PHYSICAL_PAGE_MASK (PAGE_MASK & __PHYSICAL_MASK) -#define PTE_MASK (_AT(long, PHYSICAL_PAGE_MASK)) +/* 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) + +/* PTE_MASK extracts the PFN from a (pte|pmd|pud|pgd)val_t */ +#define PTE_MASK ((pteval_t)PHYSICAL_PAGE_MASK) #define PMD_PAGE_SIZE (_AC(1, UL) << PMD_SHIFT) #define PMD_PAGE_MASK (~(PMD_PAGE_SIZE-1)) @@ -24,8 +29,8 @@ /* to align the pointer to the (next) page boundary */ #define PAGE_ALIGN(addr) (((addr)+PAGE_SIZE-1)&PAGE_MASK) -#define __PHYSICAL_MASK _AT(phys_addr_t, (_AC(1,ULL) << __PHYSICAL_MASK_SHIFT) - 1) -#define __VIRTUAL_MASK ((_AC(1,UL) << __VIRTUAL_MASK_SHIFT) - 1) +#define __PHYSICAL_MASK ((((phys_addr_t)1) << __PHYSICAL_MASK_SHIFT) - 1) +#define __VIRTUAL_MASK ((1UL << __VIRTUAL_MASK_SHIFT) - 1) #ifndef __ASSEMBLY__ #include -- cgit v1.2.3 From 1bb271db63c356212564aad050b2cf026f800858 Mon Sep 17 00:00:00 2001 From: Jeremy Fitzhardinge Date: Tue, 20 May 2008 08:26:18 +0100 Subject: x86: fix warning on 32-bit non-PAE Fix the warning: include2/asm/pgtable.h: In function `pte_modify': include2/asm/pgtable.h:290: warning: left shift count >= width of type On 32-bit PAE the virtual and physical addresses are both 32-bits, so it ends up evaluating 1<<32. Do the shift as a 64-bit shift then cast to the appropriate size. This should all be done at compile time, and so have no effect on generated code. Signed-off-by: Jeremy Fitzhardinge Tested-by: Hugh Dickins Signed-off-by: Linus Torvalds --- include/asm-x86/page.h | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'include/asm-x86/page.h') diff --git a/include/asm-x86/page.h b/include/asm-x86/page.h index 76b35e636d7..223146da2fa 100644 --- a/include/asm-x86/page.h +++ b/include/asm-x86/page.h @@ -29,7 +29,7 @@ /* to align the pointer to the (next) page boundary */ #define PAGE_ALIGN(addr) (((addr)+PAGE_SIZE-1)&PAGE_MASK) -#define __PHYSICAL_MASK ((((phys_addr_t)1) << __PHYSICAL_MASK_SHIFT) - 1) +#define __PHYSICAL_MASK ((phys_addr_t)(1ULL << __PHYSICAL_MASK_SHIFT) - 1) #define __VIRTUAL_MASK ((1UL << __VIRTUAL_MASK_SHIFT) - 1) #ifndef __ASSEMBLY__ -- cgit v1.2.3 From c57c05d0032cd5a500c5eba18ede4867a6d2cd5f Mon Sep 17 00:00:00 2001 From: Jeremy Fitzhardinge Date: Tue, 20 May 2008 08:26:19 +0100 Subject: x86: rearrange __(VIRTUAL|PHYSICAL)_MASK Put the definitions of __(VIRTUAL|PHYSICAL)_MASK before their uses. Signed-off-by: Jeremy Fitzhardinge Tested-by: Hugh Dickins Signed-off-by: Linus Torvalds --- include/asm-x86/page.h | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-) (limited to 'include/asm-x86/page.h') diff --git a/include/asm-x86/page.h b/include/asm-x86/page.h index 223146da2fa..dc936dddf16 100644 --- a/include/asm-x86/page.h +++ b/include/asm-x86/page.h @@ -10,6 +10,9 @@ #ifdef __KERNEL__ +#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 virtual addresses are 32-bits but physical addresses are larger (ie, 32-bit PAE). */ @@ -29,9 +32,6 @@ /* to align the pointer to the (next) page boundary */ #define PAGE_ALIGN(addr) (((addr)+PAGE_SIZE-1)&PAGE_MASK) -#define __PHYSICAL_MASK ((phys_addr_t)(1ULL << __PHYSICAL_MASK_SHIFT) - 1) -#define __VIRTUAL_MASK ((1UL << __VIRTUAL_MASK_SHIFT) - 1) - #ifndef __ASSEMBLY__ #include #endif -- cgit v1.2.3