summaryrefslogtreecommitdiff
path: root/arch/x86/mm/extable_64.c
diff options
context:
space:
mode:
Diffstat (limited to 'arch/x86/mm/extable_64.c')
-rw-r--r--arch/x86/mm/extable_64.c34
1 files changed, 34 insertions, 0 deletions
diff --git a/arch/x86/mm/extable_64.c b/arch/x86/mm/extable_64.c
new file mode 100644
index 000000000000..79ac6e7100af
--- /dev/null
+++ b/arch/x86/mm/extable_64.c
@@ -0,0 +1,34 @@
+/*
+ * linux/arch/x86_64/mm/extable.c
+ */
+
+#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;
+}