pve-edge-kernel/patches/kernel/0084-x86-boot-Relocate-definition-of-the-initial-state-of.patch

From e0cef0182f7d13edb48119653a4fc225b0287b5a Mon Sep 17 00:00:00 2001
From: Ricardo Neri <[email protected]>
Date: Fri, 27 Oct 2017 13:25:29 -0700
Subject: [PATCH 084/242] x86/boot: Relocate definition of the initial state of
 CR0
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CVE-2017-5754

Both head_32.S and head_64.S utilize the same value to initialize the
control register CR0. Also, other parts of the kernel might want to access
this initial definition (e.g., emulation code for User-Mode Instruction
Prevention uses this state to provide a sane dummy value for CR0 when
emulating the smsw instruction). Thus, relocate this definition to a
header file from which it can be conveniently accessed.

Suggested-by: Borislav Petkov <[email protected]>
Signed-off-by: Ricardo Neri <[email protected]>
Signed-off-by: Thomas Gleixner <[email protected]>
Reviewed-by: Borislav Petkov <[email protected]>
Reviewed-by: Andy Lutomirski <[email protected]>
Cc: "Michael S. Tsirkin" <[email protected]>
Cc: Peter Zijlstra <[email protected]>
Cc: Dave Hansen <[email protected]>
Cc: [email protected]
Cc: [email protected]
Cc: Paul Gortmaker <[email protected]>
Cc: Huang Rui <[email protected]>
Cc: Shuah Khan <[email protected]>
Cc: [email protected]
Cc: Jonathan Corbet <[email protected]>
Cc: Jiri Slaby <[email protected]>
Cc: "Ravi V. Shankar" <[email protected]>
Cc: Denys Vlasenko <[email protected]>
Cc: Chris Metcalf <[email protected]>
Cc: Brian Gerst <[email protected]>
Cc: Josh Poimboeuf <[email protected]>
Cc: Chen Yucong <[email protected]>
Cc: Vlastimil Babka <[email protected]>
Cc: Dave Hansen <[email protected]>
Cc: Andy Lutomirski <[email protected]>
Cc: Masami Hiramatsu <[email protected]>
Cc: Paolo Bonzini <[email protected]>
Cc: Andrew Morton <[email protected]>
Cc: Linus Torvalds <[email protected]>
Link: https://lkml.kernel.org/r/1509135945-13762-3-git-send-email-ricardo.neri-calderon@linux.intel.com

(cherry picked from commit b0ce5b8c95c83a7b98c679b117e3d6ae6f97154b)
Signed-off-by: Andy Whitcroft <[email protected]>
Signed-off-by: Kleber Sacilotto de Souza <[email protected]>
(cherry picked from commit 27c31a88c22edab269abe17c0ac7db0351d26c5f)
Signed-off-by: Fabian Grünbichler <[email protected]>
---
 arch/x86/include/uapi/asm/processor-flags.h | 3 +++
 arch/x86/kernel/head_32.S                   | 3 ---
 arch/x86/kernel/head_64.S                   | 3 ---
 3 files changed, 3 insertions(+), 6 deletions(-)

diff --git a/arch/x86/include/uapi/asm/processor-flags.h b/arch/x86/include/uapi/asm/processor-flags.h
index 185f3d10c194..39946d0a1d41 100644
--- a/arch/x86/include/uapi/asm/processor-flags.h
+++ b/arch/x86/include/uapi/asm/processor-flags.h
@@ -151,5 +151,8 @@
 #define CX86_ARR_BASE	0xc4
 #define CX86_RCR_BASE	0xdc
 
+#define CR0_STATE	(X86_CR0_PE | X86_CR0_MP | X86_CR0_ET | \
+			 X86_CR0_NE | X86_CR0_WP | X86_CR0_AM | \
+			 X86_CR0_PG)
 
 #endif /* _UAPI_ASM_X86_PROCESSOR_FLAGS_H */
diff --git a/arch/x86/kernel/head_32.S b/arch/x86/kernel/head_32.S
index 337a65377baf..7bbcdb1ea31a 100644
--- a/arch/x86/kernel/head_32.S
+++ b/arch/x86/kernel/head_32.S
@@ -213,9 +213,6 @@ ENTRY(startup_32_smp)
 #endif
 
 .Ldefault_entry:
-#define CR0_STATE	(X86_CR0_PE | X86_CR0_MP | X86_CR0_ET | \
-			 X86_CR0_NE | X86_CR0_WP | X86_CR0_AM | \
-			 X86_CR0_PG)
 	movl $(CR0_STATE & ~X86_CR0_PG),%eax
 	movl %eax,%cr0
 
diff --git a/arch/x86/kernel/head_64.S b/arch/x86/kernel/head_64.S
index a2d8541b1da4..4117c1e0b3d2 100644
--- a/arch/x86/kernel/head_64.S
+++ b/arch/x86/kernel/head_64.S
@@ -137,9 +137,6 @@ ENTRY(secondary_startup_64)
 1:	wrmsr				/* Make changes effective */
 
 	/* Setup cr0 */
-#define CR0_STATE	(X86_CR0_PE | X86_CR0_MP | X86_CR0_ET | \
-			 X86_CR0_NE | X86_CR0_WP | X86_CR0_AM | \
-			 X86_CR0_PG)
 	movl	$CR0_STATE, %eax
 	/* Make changes effective */
 	movq	%rax, %cr0
-- 
2.14.2