The patch titled
Subject: lib/extable.c: use bsearch() library function in search_extable()
has been added to the -mm tree. Its filename is
lib-extablec-use-bsearch-library-function-in-search_extable.patch
This patch should soon appear at
http://ozlabs.org/~akpm/mmots/broken-out/lib-extablec-use-bsearch-library-function-in-search_extable.patch
and later at
http://ozlabs.org/~akpm/mmotm/broken-out/lib-extablec-use-bsearch-library-function-in-search_extable.patch
Before you just go and hit "reply", please:
a) Consider who else should be cc'ed
b) Prefer to cc a suitable mailing list as well
c) Ideally: find the original patch on the mailing list and do a
reply-to-all to that, adding suitable additional cc's
*** Remember to use Documentation/SubmitChecklist when testing your code ***
The -mm tree is included into linux-next and is updated
there every 3-4 working days
------------------------------------------------------
From: Thomas Meyer <thomas@xxxxxxxx>
Subject: lib/extable.c: use bsearch() library function in search_extable()
Signed-off-by: Thomas Meyer <thomas@xxxxxxxx>
Cc: Rasmus Villemoes <linux@xxxxxxxxxxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
include/linux/extable.h | 3 ++-
kernel/extable.c | 2 +-
kernel/module.c | 2 +-
lib/extable.c | 38 +++++++++++++++++++-------------------
4 files changed, 23 insertions(+), 22 deletions(-)
diff -puN include/linux/extable.h~lib-extablec-use-bsearch-library-function-in-search_extable include/linux/extable.h
--- a/include/linux/extable.h~lib-extablec-use-bsearch-library-function-in-search_extable
+++ a/include/linux/extable.h
@@ -2,13 +2,14 @@
#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 struct exception_table_entry *last,
+ const size_t num,
unsigned long value);
void sort_extable(struct exception_table_entry *start,
struct exception_table_entry *finish);
diff -puN kernel/extable.c~lib-extablec-use-bsearch-library-function-in-search_extable kernel/extable.c
--- a/kernel/extable.c~lib-extablec-use-bsearch-library-function-in-search_extable
+++ a/kernel/extable.c
@@ -55,7 +55,7 @@ const struct exception_table_entry *sear
{
const struct exception_table_entry *e;
- e = search_extable(__start___ex_table, __stop___ex_table-1, addr);
+ e = search_extable(__start___ex_table, __stop___ex_table - __start___ex_table, addr);
if (!e)
e = search_module_extables(addr);
return e;
diff -puN kernel/module.c~lib-extablec-use-bsearch-library-function-in-search_extable kernel/module.c
--- a/kernel/module.c~lib-extablec-use-bsearch-library-function-in-search_extable
+++ a/kernel/module.c
@@ -4201,7 +4201,7 @@ const struct exception_table_entry *sear
goto out;
e = search_extable(mod->extable,
- mod->extable + mod->num_exentries - 1,
+ mod->num_exentries,
addr);
out:
preempt_enable();
diff -puN lib/extable.c~lib-extablec-use-bsearch-library-function-in-search_extable lib/extable.c
--- a/lib/extable.c~lib-extablec-use-bsearch-library-function-in-search_extable
+++ a/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, in
* 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
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 +94,20 @@ 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,
@@ -102,24 +117,9 @@ void trim_init_extable(struct module *m)
*/
const struct exception_table_entry *
search_extable(const struct exception_table_entry *first,
- const struct exception_table_entry *last,
+ const size_t num,
unsigned long value)
{
- 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;
+ return bsearch(&value, first, num, sizeof(struct exception_table_entry), cmp_ex_search);
}
#endif
_
Patches currently in -mm which might be from thomas@xxxxxxxx are
lib-extablec-use-bsearch-library-function-in-search_extable.patch
--
To unsubscribe from this list: send the line "unsubscribe mm-commits" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
