| lists.openwall.net | lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC | |
|
Open Source and information security mailing list archives
| ||
|
Message-ID: <20110106094821.GA18092@elte.hu>
Date: Thu, 6 Jan 2011 10:48:21 +0100
From: Ingo Molnar <mingo@...e.hu>
To: Linus Torvalds <torvalds@...ux-foundation.org>
Cc: linux-kernel@...r.kernel.org, "H. Peter Anvin" <hpa@...or.com>,
Thomas Gleixner <tglx@...utronix.de>,
Andrew Morton <akpm@...ux-foundation.org>
Subject: [GIT PULL] x86/cpu changes for v2.6.38
Linus,
Please pull the latest x86-cpu-for-linus git tree from:
git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip.git x86-cpu-for-linus
Thanks,
Ingo
------------------>
Kees Cook (5):
x86, cpu: Rename verify_cpu_64.S to verify_cpu.S
x86, cpu: Clear XD_DISABLED flag on Intel to regain NX
x86, cpu: Call verify_cpu during 32bit CPU startup
x86, cpu: Only CPU features determine NX capabilities
x86: Fix included-by file reference comments
arch/x86/boot/compressed/head_64.S | 2 +-
arch/x86/kernel/head_32.S | 6 +++
arch/x86/kernel/trampoline_64.S | 2 +-
arch/x86/kernel/{verify_cpu_64.S => verify_cpu.S} | 49 +++++++++++++++++---
arch/x86/mm/setup_nx.c | 2 +-
5 files changed, 50 insertions(+), 11 deletions(-)
rename arch/x86/kernel/{verify_cpu_64.S => verify_cpu.S} (65%)
diff --git a/arch/x86/boot/compressed/head_64.S b/arch/x86/boot/compressed/head_64.S
index 52f85a1..35af09d 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 bcece91..fdaea52 100644
--- a/arch/x86/kernel/head_32.S
+++ b/arch/x86/kernel/head_32.S
@@ -314,6 +314,10 @@ 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? */
@@ -609,6 +613,8 @@ 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 3af2dff..075d130 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
similarity index 65%
rename from arch/x86/kernel/verify_cpu_64.S
rename to arch/x86/kernel/verify_cpu.S
index 56a8c2a..0edefc1 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@...e.de)
* Copyright (c) 2007 Eric Biederman (ebiederm@...ssion.com)
* Copyright (c) 2007 Vivek Goyal (vgoyal@...ibm.com)
+ * Copyright (c) 2010 Kees Cook (kees.cook@...onical.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 a3250aa..410531d 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) {
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/
Powered by blists - more mailing lists