m68k: Add helper function handle_kernel_fault()

Add helper function handle_kernel_fault() in signal.c, so frame_extra_sizes
can become static, and to avoid future code duplication.
Signed-off-by: NRoman Zippel <zippel@linux-m68k.org>
Signed-off-by: NGeert Uytterhoeven <geert@linux-m68k.org>

arch/m68k/include/asm/processor.h

@@ -113,6 +113,8 @@ static inline void start_thread(struct pt_regs * regs, unsigned long pc,
 	wrusp(usp);
 }
 
+extern int handle_kernel_fault(struct pt_regs *regs);
+
 #else
 
 /*

arch/m68k/kernel/signal.c

@@ -42,6 +42,7 @@
 #include <linux/personality.h>
 #include <linux/tty.h>
 #include <linux/binfmts.h>
+#include <linux/module.h>
 
 #include <asm/setup.h>
 #include <asm/uaccess.h>
@@ -51,7 +52,7 @@
 
 #define _BLOCKABLE (~(sigmask(SIGKILL) | sigmask(SIGSTOP)))
 
-const int frame_extra_sizes[16] = {
+static const int frame_extra_sizes[16] = {
   [1]	= -1, /* sizeof(((struct frame *)0)->un.fmt1), */
   [2]	= sizeof(((struct frame *)0)->un.fmt2),
   [3]	= sizeof(((struct frame *)0)->un.fmt3),
@@ -69,6 +70,27 @@ const int frame_extra_sizes[16] = {
   [15]	= -1, /* sizeof(((struct frame *)0)->un.fmtf), */
 };
 
+int handle_kernel_fault(struct pt_regs *regs)
+{
+	const struct exception_table_entry *fixup;
+	struct pt_regs *tregs;
+
+	/* Are we prepared to handle this kernel fault? */
+	fixup = search_exception_tables(regs->pc);
+	if (!fixup)
+		return 0;
+
+	/* Create a new four word stack frame, discarding the old one. */
+	regs->stkadj = frame_extra_sizes[regs->format];
+	tregs =	(struct pt_regs *)((long)regs + regs->stkadj);
+	tregs->vector = regs->vector;
+	tregs->format = 0;
+	tregs->pc = fixup->fixup;
+	tregs->sr = regs->sr;
+
+	return 1;
+}
+
 /*
  * Atomically swap in the new signal mask, and wait for a signal.
  */

arch/m68k/mm/fault.c

@@ -18,7 +18,6 @@
 #include <asm/pgalloc.h>
 
 extern void die_if_kernel(char *, struct pt_regs *, long);
-extern const int frame_extra_sizes[]; /* in m68k/kernel/signal.c */
 
 int send_fault_sig(struct pt_regs *regs)
 {
@@ -35,21 +34,8 @@ int send_fault_sig(struct pt_regs *regs)
 		force_sig_info(siginfo.si_signo,
 			       &siginfo, current);
 	} else {
-		const struct exception_table_entry *fixup;
-
-		/* Are we prepared to handle this kernel fault? */
-		if ((fixup = search_exception_tables(regs->pc))) {
-			struct pt_regs *tregs;
-			/* Create a new four word stack frame, discarding the old
-			   one.  */
-			regs->stkadj = frame_extra_sizes[regs->format];
-			tregs =	(struct pt_regs *)((ulong)regs + regs->stkadj);
-			tregs->vector = regs->vector;
-			tregs->format = 0;
-			tregs->pc = fixup->fixup;
-			tregs->sr = regs->sr;
+		if (handle_kernel_fault(regs))
 			return -1;
-		}
 
 		//if (siginfo.si_signo == SIGBUS)
 		//	force_sig_info(siginfo.si_signo,