Revert "lib/extable.c: use bsearch() library function in search_extable()"

This reverts commit 222785199d50099d847bd4b0613e3b0eb22e8d5e.

4 files changed, 22 insertions, 23 deletions

diff --git a/include/linux/extable.h b/include/linux/extable.h
index b575bb9b5285..7effea4b257d 100644
--- a/include/linux/extable.h
+++ b/include/linux/extable.h
@@ -2,14 +2,13 @@
 #define _LINUX_EXTABLE_H
 
 #include <linux/stddef.h>	/* for NULL */
-#include <linux/types.h>
 
 struct module;
 struct exception_table_entry;
 
 const struct exception_table_entry *
 search_extable(const struct exception_table_entry *first,
-	       const size_t num,
+	       const struct exception_table_entry *last,
 	       unsigned long value);
 void sort_extable(struct exception_table_entry *start,
 		  struct exception_table_entry *finish);
diff --git a/kernel/extable.c b/kernel/extable.c
index 78604baab401..0fbdd8582f08 100644
--- a/kernel/extable.c
+++ b/kernel/extable.c
@@ -55,7 +55,7 @@ const struct exception_table_entry *search_exception_tables(unsigned long addr)
 {
 	const struct exception_table_entry *e;
 
-	e = search_extable(__start___ex_table, __stop___ex_table - __start___ex_table, addr);
+	e = search_extable(__start___ex_table, __stop___ex_table-1, addr);
 	if (!e)
 		e = search_module_extables(addr);
 	return e;
diff --git a/kernel/module.c b/kernel/module.c
index 065032b734d2..e3e9dbba6a5b 100644
--- a/kernel/module.c
+++ b/kernel/module.c
@@ -4211,7 +4211,7 @@ const struct exception_table_entry *search_module_extables(unsigned long addr)
 		goto out;
 
 	e = search_extable(mod->extable,
-			   mod->num_exentries,
+			   mod->extable + mod->num_exentries - 1,
 			   addr);
 out:
 	preempt_enable();
diff --git a/lib/extable.c b/lib/extable.c
index 4f84fe1f57f3..62968daa66a9 100644
--- a/lib/extable.c
+++ b/lib/extable.c
@@ -9,7 +9,6 @@
  * 2 of the License, or (at your option) any later version.
  */
 
-#include <linux/bsearch.h>
 #include <linux/module.h>
 #include <linux/init.h>
 #include <linux/sort.h>
@@ -52,7 +51,7 @@ static void swap_ex(void *a, void *b, int size)
  * This is used both for the kernel exception table and for
  * the exception tables of modules that get loaded.
  */
-static int cmp_ex_sort(const void *a, const void *b)
+static int cmp_ex(const void *a, const void *b)
 {
 	const struct exception_table_entry *x = a, *y = b;
 
@@ -68,7 +67,7 @@ void sort_extable(struct exception_table_entry *start,
 		  struct exception_table_entry *finish)
 {
 	sort(start, finish - start, sizeof(struct exception_table_entry),
-	     cmp_ex_sort, swap_ex);
+	     cmp_ex, swap_ex);
 }
 
 #ifdef CONFIG_MODULES
@@ -94,20 +93,6 @@ void trim_init_extable(struct module *m)
 #endif /* !ARCH_HAS_SORT_EXTABLE */
 
 #ifndef ARCH_HAS_SEARCH_EXTABLE
-
-static int cmp_ex_search(const void *key, const void *elt)
-{
-	const struct exception_table_entry * _elt = elt;
-	unsigned long k = *(unsigned long*) key;
-
-	/* avoid overflow */
-	if (k > ex_to_insn(_elt))
-		return 1;
-	if (k < ex_to_insn(_elt))
-		return -1;
-	return 0;
-}
-
 /*
  * Search one exception table for an entry corresponding to the
  * given instruction address, and return the address of the entry,
@@ -117,9 +102,24 @@ static int cmp_ex_search(const void *key, const void *elt)
  */
 const struct exception_table_entry *
 search_extable(const struct exception_table_entry *first,
-	       const size_t num,
+	       const struct exception_table_entry *last,
 	       unsigned long value)
 {
-	return bsearch(&value, first, num, sizeof(struct exception_table_entry), cmp_ex_search);
+	while (first <= last) {
+		const struct exception_table_entry *mid;
+
+		mid = ((last - first) >> 1) + first;
+		/*
+		 * careful, the distance between value and insn
+		 * can be larger than MAX_LONG:
+		 */
+		if (ex_to_insn(mid) < value)
+			first = mid + 1;
+		else if (ex_to_insn(mid) > value)
+			last = mid - 1;
+		else
+			return mid;
+	}
+	return NULL;
 }
 #endif