diff options
| -rw-r--r-- | arch/x86/boot/compressed/head_64.S | 2 | ||||
| -rw-r--r-- | arch/x86/kernel/head_32.S | 6 | ||||
| -rw-r--r-- | arch/x86/kernel/trampoline_64.S | 2 | ||||
| -rw-r--r-- | arch/x86/kernel/verify_cpu.S (renamed from arch/x86/kernel/verify_cpu_64.S) | 49 | ||||
| -rw-r--r-- | arch/x86/mm/setup_nx.c | 2 |
5 files changed, 50 insertions, 11 deletions
diff --git a/arch/x86/boot/compressed/head_64.S b/arch/x86/boot/compressed/head_64.S index 52f85a196fa..35af09d13dc 100644 --- a/arch/x86/boot/compressed/head_64.S +++ b/arch/x86/boot/compressed/head_64.S @@ -182,7 +182,7 @@ no_longmode: hlt jmp 1b -#include "../../kernel/verify_cpu_64.S" +#include "../../kernel/verify_cpu.S" /* * Be careful here startup_64 needs to be at a predictable diff --git a/arch/x86/kernel/head_32.S b/arch/x86/kernel/head_32.S index c0dbd9ac24f..5707fc8a7a4 100644 --- a/arch/x86/kernel/head_32.S +++ b/arch/x86/kernel/head_32.S @@ -316,6 +316,10 @@ ENTRY(startup_32_smp) subl $0x80000001, %eax cmpl $(0x8000ffff-0x80000001), %eax ja 6f + + /* Clear bogus XD_DISABLE bits */ + call verify_cpu + mov $0x80000001, %eax cpuid /* Execute Disable bit supported? */ @@ -611,6 +615,8 @@ ignore_int: #endif iret +#include "verify_cpu.S" + __REFDATA .align 4 ENTRY(initial_code) diff --git a/arch/x86/kernel/trampoline_64.S b/arch/x86/kernel/trampoline_64.S index 3af2dff58b2..075d130efcf 100644 --- a/arch/x86/kernel/trampoline_64.S +++ b/arch/x86/kernel/trampoline_64.S @@ -127,7 +127,7 @@ startup_64: no_longmode: hlt jmp no_longmode -#include "verify_cpu_64.S" +#include "verify_cpu.S" # Careful these need to be in the same 64K segment as the above; tidt: diff --git a/arch/x86/kernel/verify_cpu_64.S b/arch/x86/kernel/verify_cpu.S index 56a8c2a867d..0edefc19a11 100644 --- a/arch/x86/kernel/verify_cpu_64.S +++ b/arch/x86/kernel/verify_cpu.S @@ -7,6 +7,7 @@ * Copyright (c) 2007 Andi Kleen (ak@suse.de) * Copyright (c) 2007 Eric Biederman (ebiederm@xmission.com) * Copyright (c) 2007 Vivek Goyal (vgoyal@in.ibm.com) + * Copyright (c) 2010 Kees Cook (kees.cook@canonical.com) * * This source code is licensed under the GNU General Public License, * Version 2. See the file COPYING for more details. @@ -14,18 +15,17 @@ * This is a common code for verification whether CPU supports * long mode and SSE or not. It is not called directly instead this * file is included at various places and compiled in that context. - * Following are the current usage. + * This file is expected to run in 32bit code. Currently: * - * This file is included by both 16bit and 32bit code. + * arch/x86/boot/compressed/head_64.S: Boot cpu verification + * arch/x86/kernel/trampoline_64.S: secondary processor verfication + * arch/x86/kernel/head_32.S: processor startup * - * arch/x86_64/boot/setup.S : Boot cpu verification (16bit) - * arch/x86_64/boot/compressed/head.S: Boot cpu verification (32bit) - * arch/x86_64/kernel/trampoline.S: secondary processor verfication (16bit) - * arch/x86_64/kernel/acpi/wakeup.S:Verfication at resume (16bit) - * - * verify_cpu, returns the status of cpu check in register %eax. + * verify_cpu, returns the status of longmode and SSE in register %eax. * 0: Success 1: Failure * + * On Intel, the XD_DISABLE flag will be cleared as a side-effect. + * * The caller needs to check for the error code and take the action * appropriately. Either display a message or halt. */ @@ -62,8 +62,41 @@ verify_cpu: cmpl $0x444d4163,%ecx jnz verify_cpu_noamd mov $1,%di # cpu is from AMD + jmp verify_cpu_check verify_cpu_noamd: + cmpl $0x756e6547,%ebx # GenuineIntel? + jnz verify_cpu_check + cmpl $0x49656e69,%edx + jnz verify_cpu_check + cmpl $0x6c65746e,%ecx + jnz verify_cpu_check + + # only call IA32_MISC_ENABLE when: + # family > 6 || (family == 6 && model >= 0xd) + movl $0x1, %eax # check CPU family and model + cpuid + movl %eax, %ecx + + andl $0x0ff00f00, %eax # mask family and extended family + shrl $8, %eax + cmpl $6, %eax + ja verify_cpu_clear_xd # family > 6, ok + jb verify_cpu_check # family < 6, skip + + andl $0x000f00f0, %ecx # mask model and extended model + shrl $4, %ecx + cmpl $0xd, %ecx + jb verify_cpu_check # family == 6, model < 0xd, skip + +verify_cpu_clear_xd: + movl $MSR_IA32_MISC_ENABLE, %ecx + rdmsr + btrl $2, %edx # clear MSR_IA32_MISC_ENABLE_XD_DISABLE + jnc verify_cpu_check # only write MSR if bit was changed + wrmsr + +verify_cpu_check: movl $0x1,%eax # Does the cpu have what it takes cpuid andl $REQUIRED_MASK0,%edx diff --git a/arch/x86/mm/setup_nx.c b/arch/x86/mm/setup_nx.c index a3250aa3408..410531d3c29 100644 --- a/arch/x86/mm/setup_nx.c +++ b/arch/x86/mm/setup_nx.c @@ -41,7 +41,7 @@ void __init x86_report_nx(void) { if (!cpu_has_nx) { printk(KERN_NOTICE "Notice: NX (Execute Disable) protection " - "missing in CPU or disabled in BIOS!\n"); + "missing in CPU!\n"); } else { #if defined(CONFIG_X86_64) || defined(CONFIG_X86_PAE) if (disable_nx) { |