[PATCH] ia64 extable sorting fix

Fix a goofup from the recent sort consolidation patches.

- Subtractions in comparison functions could overflow the return type for
  64-bit pointers.  Make it right again.

- Add missing size arg to ia64 extable swap function.
Signed-off-by: Matt Mackall <mpm@selenic.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

arch/ia64/mm/extable.c

@@ -17,10 +17,15 @@ static int cmp_ex(const void *a, const void *b)
 	u64 lip = (u64) &l->addr + l->addr;
 	u64 rip = (u64) &r->addr + r->addr;
 
-	return lip - rip;
+	/* avoid overflow */
+	if (lip > rip)
+		return 1;
+	if (lip < rip)
+		return -1;
+	return 0;
 }
 
-static void swap_ex(void *a, void *b)
+static void swap_ex(void *a, void *b, int size)
 {
 	struct exception_table_entry *l = a, *r = b, tmp;
 	u64 delta = (u64) r - (u64) l;

lib/extable.c

@@ -29,7 +29,13 @@ extern struct exception_table_entry __stop___ex_table[];
 static int cmp_ex(const void *a, const void *b)
 {
 	const struct exception_table_entry *x = a, *y = b;
-	return x->insn - y->insn;
+
+	/* avoid overflow */
+	if (x->insn > y->insn)
+		return 1;
+	if (x->insn < y->insn)
+		return -1;
+	return 0;
 }
 
 void sort_extable(struct exception_table_entry *start,