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Subject[PATCH] lib/extable.c: use bsearch() library function in search_extable()
From
Date
Signed-off-by: Thomas Meyer <thomas@m3y3r.de>
---
 lib/extable.c | 30 +++++++++++++-----------------
 1 file changed, 13 insertions(+), 17 deletions(-)

diff --git a/lib/extable.c b/lib/extable.c
index 62968da..eb16cb3 100644
--- a/lib/extable.c
+++ b/lib/extable.c
@@ -9,6 +9,7 @@
  * 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>
@@ -51,7 +52,7 @@ 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(const void *a, const void *b)
+static int cmp_ex_sort(const void *a, const void *b)
 {
  const struct exception_table_entry *x = a, *y = b;
 
@@ -67,7 +68,7 @@ void sort_extable(struct exception_table_entry *start,
    struct exception_table_entry *finish)
 {
  sort(start, finish - start, sizeof(struct exception_table_entry),
-      cmp_ex, swap_ex);
+      cmp_ex_sort, swap_ex);
 }
 
 #ifdef CONFIG_MODULES
@@ -93,6 +94,13 @@ 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;
+ return *(unsigned long*) key - ex_to_insn(_elt);
+}
+
 /*
  * Search one exception table for an entry corresponding to the
  * given instruction address, and return the address of the entry,
@@ -105,21 +113,9 @@ search_extable(const struct exception_table_entry *first,
         const struct exception_table_entry *last,
         unsigned long value)
 {
- while (first <= last) {
- const struct exception_table_entry *mid;
+ if(last < first)
+ return NULL;
 
- 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;
+ return bsearch(&value, first, last - first + 1, sizeof(struct exception_table_entry), cmp_ex_search);
 }
 #endif

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