1 files changed, 35 insertions, 0 deletions

diff --git a/arch/x86_64/mm/extable.c b/arch/x86_64/mm/extable.c
new file mode 100644
index 000000000000..2d78f9fb4035
--- /dev/null
+++ b/arch/x86_64/mm/extable.c
@@ -0,0 +1,35 @@
+/*
+ * linux/arch/x86_64/mm/extable.c
+ */
+
+#include <linux/config.h>
+#include <linux/module.h>
+#include <linux/spinlock.h>
+#include <linux/init.h>
+#include <asm/uaccess.h>
+
+/* Simple binary search */
+const struct exception_table_entry *
+search_extable(const struct exception_table_entry *first,
+               const struct exception_table_entry *last,
+               unsigned long value)
+{
+        /* Work around a B stepping K8 bug */
+        if ((value >> 32) == 0)
+                value |= 0xffffffffUL << 32; 
+
+        while (first <= last) {
+                const struct exception_table_entry *mid;
+                long diff;
+
+                mid = (last - first) / 2 + first;
+                diff = mid->insn - value;
+                if (diff == 0)
+                        return mid;
+                else if (diff < 0)
+                        first = mid+1;
+                else
+                        last = mid-1;
+        }
+        return NULL;
+}