[PATCH 2/5] x86: Add symbolic constant for exceptions with error code

["H. Peter Anvin" <hpa@zytor.com>]

From: "H. Peter Anvin" <hpa@zytor.com>

Add a symbolic constant for the bitmask which states which exceptions
carry an error code.

Signed-off-by: H. Peter Anvin <hpa@zytor.com>
---
 arch/x86/include/asm/segment.h |    2 ++
 arch/x86/kernel/head_64.S      |    2 +-
 2 files changed, 3 insertions(+), 1 deletions(-)

diff --git a/arch/x86/include/asm/segment.h b/arch/x86/include/asm/segment.h
index 1654662..58c1e6c 100644
--- a/arch/x86/include/asm/segment.h
+++ b/arch/x86/include/asm/segment.h
@@ -205,6 +205,8 @@
 
 #define IDT_ENTRIES 256
 #define NUM_EXCEPTION_VECTORS 32
+/* Bitmask of exception vectors which push an error code on the stack */
+#define EXCEPTION_ERRCODE_MASK  0x00027d00
 #define GDT_SIZE (GDT_ENTRIES * 8)
 #define GDT_ENTRY_TLS_ENTRIES 3
 #define TLS_SIZE (GDT_ENTRY_TLS_ENTRIES * 8)
diff --git a/arch/x86/kernel/head_64.S b/arch/x86/kernel/head_64.S
index 40f4eb3..adf52e8 100644
--- a/arch/x86/kernel/head_64.S
+++ b/arch/x86/kernel/head_64.S
@@ -295,7 +295,7 @@ ENTRY(early_idt_handler)
 	ja 0f
 	movl $1,%eax
 	salq %cl,%rax
-	testl $0x27d00,%eax
+	testl $EXCEPTION_ERRCODE_MASK,%eax
 	je 0f
 	popq %r8		# get error code
 0:	movq 0(%rsp),%rcx	# get ip
-- 
1.7.6.5