x86: Add symbolic constant for exceptions with error code

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

Signed-off-by: H. Peter Anvin <hpa@zytor.com>
Link: http://lkml.kernel.org/r/1334794610-5546-3-git-send-email-hpa@zytor.com

diff --git a/arch/x86/include/asm/segment.h b/arch/x86/include/asm/segment.h
index 1654662..58c1e6c 100644 (file)
--- 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 (file)
--- 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