x86: Introduce GDT_ENTRY_INIT()

GDT_ENTRY_INIT is static initializer of desc_struct.

We already have similar macro GDT_ENTRY() but it's static
initializer for u64 and it cannot be used for desc_struct.

Signed-off-by: Akinobu Mita <akinobu.mita@gmail.com>
LKML-Reference: <20090718151219.GD11294@localhost.localdomain>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
diff --git a/arch/x86/include/asm/desc_defs.h b/arch/x86/include/asm/desc_defs.h
index a6adefa..9d66848 100644
--- a/arch/x86/include/asm/desc_defs.h
+++ b/arch/x86/include/asm/desc_defs.h
@@ -34,6 +34,12 @@
 	};
 } __attribute__((packed));
 
+#define GDT_ENTRY_INIT(flags, base, limit) { { { \
+		.a = ((limit) & 0xffff) | (((base) & 0xffff) << 16), \
+		.b = (((base) & 0xff0000) >> 16) | (((flags) & 0xf0ff) << 8) | \
+			((limit) & 0xf0000) | ((base) & 0xff000000), \
+	} } }
+
 enum {
 	GATE_INTERRUPT = 0xE,
 	GATE_TRAP = 0xF,
diff --git a/arch/x86/include/asm/lguest.h b/arch/x86/include/asm/lguest.h
index 313389c..94cd698 100644
--- a/arch/x86/include/asm/lguest.h
+++ b/arch/x86/include/asm/lguest.h
@@ -91,8 +91,9 @@
 }
 
 /* Full 4G segment descriptors, suitable for CS and DS. */
-#define FULL_EXEC_SEGMENT ((struct desc_struct){ { {0x0000ffff, 0x00cf9b00} } })
-#define FULL_SEGMENT ((struct desc_struct){ { {0x0000ffff, 0x00cf9300} } })
+#define FULL_EXEC_SEGMENT \
+	((struct desc_struct)GDT_ENTRY_INIT(0xc09b, 0, 0xfffff))
+#define FULL_SEGMENT ((struct desc_struct)GDT_ENTRY_INIT(0xc093, 0, 0xfffff))
 
 #endif /* __ASSEMBLY__ */
 
diff --git a/arch/x86/include/asm/stackprotector.h b/arch/x86/include/asm/stackprotector.h
index cdc5e0b..44efdff 100644
--- a/arch/x86/include/asm/stackprotector.h
+++ b/arch/x86/include/asm/stackprotector.h
@@ -48,7 +48,7 @@
  * head_32 for boot CPU and setup_per_cpu_areas() for others.
  */
 #define GDT_STACK_CANARY_INIT						\
-	[GDT_ENTRY_STACK_CANARY] = { { { 0x00000018, 0x00409000 } } },
+	[GDT_ENTRY_STACK_CANARY] = GDT_ENTRY_INIT(0x4090, 0, 0x18),
 
 /*
  * Initialize the stackprotector canary value.