diff options
| -rw-r--r-- | arch/x86/include/asm/fixmap.h | 1 | ||||
| -rw-r--r-- | arch/x86/include/asm/pgtable_types.h | 2 | ||||
| -rw-r--r-- | arch/x86/include/asm/vvar.h | 22 | ||||
| -rw-r--r-- | arch/x86/kernel/vmlinux.lds.S | 28 | ||||
| -rw-r--r-- | arch/x86/kernel/vsyscall_64.c | 5 |
5 files changed, 35 insertions, 23 deletions
diff --git a/arch/x86/include/asm/fixmap.h b/arch/x86/include/asm/fixmap.h index 4729b2b6311..460c74e4852 100644 --- a/arch/x86/include/asm/fixmap.h +++ b/arch/x86/include/asm/fixmap.h @@ -78,6 +78,7 @@ enum fixed_addresses { VSYSCALL_LAST_PAGE, VSYSCALL_FIRST_PAGE = VSYSCALL_LAST_PAGE + ((VSYSCALL_END-VSYSCALL_START) >> PAGE_SHIFT) - 1, + VVAR_PAGE, VSYSCALL_HPET, #endif FIX_DBGP_BASE, diff --git a/arch/x86/include/asm/pgtable_types.h b/arch/x86/include/asm/pgtable_types.h index d56187c6b83..6a29aed6590 100644 --- a/arch/x86/include/asm/pgtable_types.h +++ b/arch/x86/include/asm/pgtable_types.h @@ -108,6 +108,7 @@ #define __PAGE_KERNEL_UC_MINUS (__PAGE_KERNEL | _PAGE_PCD) #define __PAGE_KERNEL_VSYSCALL (__PAGE_KERNEL_RX | _PAGE_USER) #define __PAGE_KERNEL_VSYSCALL_NOCACHE (__PAGE_KERNEL_VSYSCALL | _PAGE_PCD | _PAGE_PWT) +#define __PAGE_KERNEL_VVAR (__PAGE_KERNEL_RO | _PAGE_USER) #define __PAGE_KERNEL_LARGE (__PAGE_KERNEL | _PAGE_PSE) #define __PAGE_KERNEL_LARGE_NOCACHE (__PAGE_KERNEL | _PAGE_CACHE_UC | _PAGE_PSE) #define __PAGE_KERNEL_LARGE_EXEC (__PAGE_KERNEL_EXEC | _PAGE_PSE) @@ -130,6 +131,7 @@ #define PAGE_KERNEL_LARGE_EXEC __pgprot(__PAGE_KERNEL_LARGE_EXEC) #define PAGE_KERNEL_VSYSCALL __pgprot(__PAGE_KERNEL_VSYSCALL) #define PAGE_KERNEL_VSYSCALL_NOCACHE __pgprot(__PAGE_KERNEL_VSYSCALL_NOCACHE) +#define PAGE_KERNEL_VVAR __pgprot(__PAGE_KERNEL_VVAR) #define PAGE_KERNEL_IO __pgprot(__PAGE_KERNEL_IO) #define PAGE_KERNEL_IO_NOCACHE __pgprot(__PAGE_KERNEL_IO_NOCACHE) diff --git a/arch/x86/include/asm/vvar.h b/arch/x86/include/asm/vvar.h index a4eaca4a613..de656ac2af4 100644 --- a/arch/x86/include/asm/vvar.h +++ b/arch/x86/include/asm/vvar.h @@ -10,15 +10,14 @@ * In normal kernel code, they are used like any other variable. * In user code, they are accessed through the VVAR macro. * - * Each of these variables lives in the vsyscall page, and each - * one needs a unique offset within the little piece of the page - * reserved for vvars. Specify that offset in DECLARE_VVAR. - * (There are 896 bytes available. If you mess up, the linker will - * catch it.) + * These variables live in a page of kernel data that has an extra RO + * mapping for userspace. Each variable needs a unique offset within + * that page; specify that offset with the DECLARE_VVAR macro. (If + * you mess up, the linker will catch it.) */ -/* Offset of vars within vsyscall page */ -#define VSYSCALL_VARS_OFFSET (3072 + 128) +/* Base address of vvars. This is not ABI. */ +#define VVAR_ADDRESS (-10*1024*1024 - 4096) #if defined(__VVAR_KERNEL_LDS) @@ -26,17 +25,17 @@ * right place. */ #define DECLARE_VVAR(offset, type, name) \ - EMIT_VVAR(name, VSYSCALL_VARS_OFFSET + offset) + EMIT_VVAR(name, offset) #else #define DECLARE_VVAR(offset, type, name) \ static type const * const vvaraddr_ ## name = \ - (void *)(VSYSCALL_START + VSYSCALL_VARS_OFFSET + (offset)); + (void *)(VVAR_ADDRESS + (offset)); #define DEFINE_VVAR(type, name) \ - type __vvar_ ## name \ - __attribute__((section(".vsyscall_var_" #name), aligned(16))) + type name \ + __attribute__((section(".vvar_" #name), aligned(16))) #define VVAR(name) (*vvaraddr_ ## name) @@ -49,4 +48,3 @@ DECLARE_VVAR(16, int, vgetcpu_mode) DECLARE_VVAR(128, struct vsyscall_gtod_data, vsyscall_gtod_data) #undef DECLARE_VVAR -#undef VSYSCALL_VARS_OFFSET diff --git a/arch/x86/kernel/vmlinux.lds.S b/arch/x86/kernel/vmlinux.lds.S index 89aed99aafc..98b378dc7f8 100644 --- a/arch/x86/kernel/vmlinux.lds.S +++ b/arch/x86/kernel/vmlinux.lds.S @@ -161,12 +161,6 @@ SECTIONS #define VVIRT_OFFSET (VSYSCALL_ADDR - __vsyscall_0) #define VVIRT(x) (ADDR(x) - VVIRT_OFFSET) -#define EMIT_VVAR(x, offset) .vsyscall_var_ ## x \ - ADDR(.vsyscall_0) + offset \ - : AT(VLOAD(.vsyscall_var_ ## x)) { \ - *(.vsyscall_var_ ## x) \ - } \ - x = VVIRT(.vsyscall_var_ ## x); . = ALIGN(4096); __vsyscall_0 = .; @@ -192,19 +186,31 @@ SECTIONS *(.vsyscall_3) } -#define __VVAR_KERNEL_LDS -#include <asm/vvar.h> -#undef __VVAR_KERNEL_LDS - - . = __vsyscall_0 + PAGE_SIZE; + . = ALIGN(__vsyscall_0 + PAGE_SIZE, PAGE_SIZE); #undef VSYSCALL_ADDR #undef VLOAD_OFFSET #undef VLOAD #undef VVIRT_OFFSET #undef VVIRT + + __vvar_page = .; + + .vvar : AT(ADDR(.vvar) - LOAD_OFFSET) { + + /* Place all vvars at the offsets in asm/vvar.h. */ +#define EMIT_VVAR(name, offset) \ + . = offset; \ + *(.vvar_ ## name) +#define __VVAR_KERNEL_LDS +#include <asm/vvar.h> +#undef __VVAR_KERNEL_LDS #undef EMIT_VVAR + } :data + + . = ALIGN(__vvar_page + PAGE_SIZE, PAGE_SIZE); + #endif /* CONFIG_X86_64 */ /* Init code and data - will be freed after init */ diff --git a/arch/x86/kernel/vsyscall_64.c b/arch/x86/kernel/vsyscall_64.c index 3e682184d76..3cf1cef75a6 100644 --- a/arch/x86/kernel/vsyscall_64.c +++ b/arch/x86/kernel/vsyscall_64.c @@ -284,9 +284,14 @@ void __init map_vsyscall(void) { extern char __vsyscall_0; unsigned long physaddr_page0 = __pa_symbol(&__vsyscall_0); + extern char __vvar_page; + unsigned long physaddr_vvar_page = __pa_symbol(&__vvar_page); /* Note that VSYSCALL_MAPPED_PAGES must agree with the code below. */ __set_fixmap(VSYSCALL_FIRST_PAGE, physaddr_page0, PAGE_KERNEL_VSYSCALL); + __set_fixmap(VVAR_PAGE, physaddr_vvar_page, PAGE_KERNEL_VVAR); + BUILD_BUG_ON((unsigned long)__fix_to_virt(VVAR_PAGE) != + (unsigned long)VVAR_ADDRESS); } static int __init vsyscall_init(void) |