x86: signal: rename sigframe and rt_sigframe on 32-bit

Impact: cleanup, prepare to move sigframe.h

On 32-bit, rename struct sigrame to struct sigframe_ia32, struct rt_sigframe
to struct rt_sigframe_ia32 and several structures.

And add helper macros to access the above data in arch/x86/kernel/signal.c.
Signed-off-by: Hiroshi Shimamoto <h-shimamoto@ct.jp.nec.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

arch/x86/kernel/sigframe.h

 #ifdef CONFIG_X86_32
-struct sigframe {
-	char __user *pretcode;
+#define sigframe_ia32		sigframe
+#define rt_sigframe_ia32	rt_sigframe
+#define sigcontext_ia32		sigcontext
+#define _fpstate_ia32		_fpstate
+#define ucontext_ia32		ucontext
+
+struct sigframe_ia32 {
+	u32 pretcode;
 	int sig;
-	struct sigcontext sc;
+	struct sigcontext_ia32 sc;
 	/*
 	 * fpstate is unused. fpstate is moved/allocated after
 	 * retcode[] below. This movement allows to have the FP state and the
@@ -11,27 +17,27 @@ struct sigframe {
 	 * the offset of extramask[] in the sigframe and thus prevent any
 	 * legacy application accessing/modifying it.
 	 */
-	struct _fpstate fpstate_unused;
+	struct _fpstate_ia32 fpstate_unused;
 	unsigned long extramask[_NSIG_WORDS-1];
 	char retcode[8];
 	/* fp state follows here */
 };
 
-struct rt_sigframe {
-	char __user *pretcode;
+struct rt_sigframe_ia32 {
+	u32 pretcode;
 	int sig;
-	struct siginfo __user *pinfo;
-	void __user *puc;
+	u32 pinfo;
+	u32 puc;
 	struct siginfo info;
-	struct ucontext uc;
+	struct ucontext_ia32 uc;
 	char retcode[8];
 	/* fp state follows here */
 };
-#else
+#else /* !CONFIG_X86_32 */
 struct rt_sigframe {
 	char __user *pretcode;
 	struct ucontext uc;
 	struct siginfo info;
 	/* fp state follows here */
 };
-#endif
+#endif /* CONFIG_X86_32 */