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: Roman Zippel <zippel@linux-m68k.org>
Signed-off-by: Geert Uytterhoeven <geert@linux-m68k.org>

1 files changed, 23 insertions, 1 deletions

diff --git a/arch/m68k/kernel/signal.c b/arch/m68k/kernel/signal.c
index d12c3b0d9e4f..a0afc239304e 100644
--- a/arch/m68k/kernel/signal.c
+++ b/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.
  */