From d319bb79afa4039bda6f85661d6bf0c13299ce93 Mon Sep 17 00:00:00 2001 From: Andy Lutomirski Date: Sun, 5 Jun 2011 13:50:21 -0400 Subject: [PATCH] x86-64: Map the HPET NX Currently the HPET mapping is a user-accessible syscall instruction at a fixed address some of the time. A sufficiently determined hacker might be able to guess when. Signed-off-by: Andy Lutomirski Cc: Jesper Juhl Cc: Borislav Petkov Cc: Linus Torvalds Cc: Arjan van de Ven Cc: Jan Beulich Cc: richard -rw- weinberger Cc: Mikael Pettersson Cc: Andi Kleen Cc: Brian Gerst Cc: Louis Rilling Cc: Valdis.Kletnieks@vt.edu Cc: pageexec@freemail.hu Link: http://lkml.kernel.org/r/ab41b525a4ca346b1ca1145d16fb8d181861a8aa.1307292171.git.luto@mit.edu Signed-off-by: Ingo Molnar --- arch/x86/include/asm/pgtable_types.h | 4 ++-- arch/x86/kernel/hpet.c | 2 +- 2 files changed, 3 insertions(+), 3 deletions(-) diff --git a/arch/x86/include/asm/pgtable_types.h b/arch/x86/include/asm/pgtable_types.h index 6a29aed6..013286a1 100644 --- a/arch/x86/include/asm/pgtable_types.h +++ b/arch/x86/include/asm/pgtable_types.h @@ -107,8 +107,8 @@ #define __PAGE_KERNEL_NOCACHE (__PAGE_KERNEL | _PAGE_PCD | _PAGE_PWT) #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_VVAR_NOCACHE (__PAGE_KERNEL_VVAR | _PAGE_PCD | _PAGE_PWT) #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) @@ -130,8 +130,8 @@ #define PAGE_KERNEL_LARGE_NOCACHE __pgprot(__PAGE_KERNEL_LARGE_NOCACHE) #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_VVAR_NOCACHE __pgprot(__PAGE_KERNEL_VVAR_NOCACHE) #define PAGE_KERNEL_IO __pgprot(__PAGE_KERNEL_IO) #define PAGE_KERNEL_IO_NOCACHE __pgprot(__PAGE_KERNEL_IO_NOCACHE) diff --git a/arch/x86/kernel/hpet.c b/arch/x86/kernel/hpet.c index 6781765..e9f5605 100644 --- a/arch/x86/kernel/hpet.c +++ b/arch/x86/kernel/hpet.c @@ -71,7 +71,7 @@ static inline void hpet_set_mapping(void) { hpet_virt_address = ioremap_nocache(hpet_address, HPET_MMAP_SIZE); #ifdef CONFIG_X86_64 - __set_fixmap(VSYSCALL_HPET, hpet_address, PAGE_KERNEL_VSYSCALL_NOCACHE); + __set_fixmap(VSYSCALL_HPET, hpet_address, PAGE_KERNEL_VVAR_NOCACHE); #endif } -- 2.7.4