ppc64: sort exception table

arch/ppc64/kernel/setup.c

@@ -539,6 +539,7 @@ void __init setup_arch(char **cmdline_p)
 	ppc_md.setup_arch();
 
 	paging_init();
+	sort_exception_table();
 	ppc_md.progress("setup_arch: exit", 0x3eab);
 }
 

arch/ppc64/mm/extable.c

@@ -9,11 +9,47 @@
  *      2 of the License, or (at your option) any later version.
  */
 
+#include <linux/config.h>
 #include <linux/module.h>
 #include <asm/uaccess.h>
 
-extern const struct exception_table_entry __start___ex_table[];
-extern const struct exception_table_entry __stop___ex_table[];
+extern struct exception_table_entry __start___ex_table[];
+extern struct exception_table_entry __stop___ex_table[];
+
+/*
+ * The exception table needs to be sorted because we use the macros
+ * which put things into the exception table in a variety of segments
+ * such as the prep, pmac, chrp, etc. segments as well as the init
+ * segment and the main kernel text segment.
+ */
+static inline void
+sort_ex_table(struct exception_table_entry *start,
+	      struct exception_table_entry *finish)
+{
+	struct exception_table_entry el, *p, *q;
+
+	/* insertion sort */
+	for (p = start + 1; p < finish; ++p) {
+		/* start .. p-1 is sorted */
+		if (p[0].insn < p[-1].insn) {
+			/* move element p down to its right place */
+			el = *p;
+			q = p;
+			do {
+				/* el comes before q[-1], move q[-1] up one */
+				q[0] = q[-1];
+				--q;
+			} while (q > start && el.insn < q[-1].insn);
+			*q = el;
+		}
+	}
+}
+
+void
+sort_exception_table(void)
+{
+	sort_ex_table(__start___ex_table, __stop___ex_table);
+}
 
 static inline unsigned long
 search_one_table(const struct exception_table_entry *first,