1 files changed, 91 insertions, 0 deletions

diff --git a/arch/frv/mm/extable.c b/arch/frv/mm/extable.c
new file mode 100644
index 000000000000..41be1128dc64
--- /dev/null
+++ b/arch/frv/mm/extable.c
@@ -0,0 +1,91 @@
+/*
+ * linux/arch/frv/mm/extable.c
+ */
+
+#include <linux/config.h>
+#include <linux/module.h>
+#include <linux/spinlock.h>
+#include <asm/uaccess.h>
+
+extern const struct exception_table_entry __attribute__((aligned(8))) __start___ex_table[];
+extern const struct exception_table_entry __attribute__((aligned(8))) __stop___ex_table[];
+extern const void __memset_end, __memset_user_error_lr, __memset_user_error_handler;
+extern const void __memcpy_end, __memcpy_user_error_lr, __memcpy_user_error_handler;
+extern spinlock_t modlist_lock;
+
+/*****************************************************************************/
+/*
+ *
+ */
+static inline unsigned long search_one_table(const struct exception_table_entry *first,
+                                             const struct exception_table_entry *last,
+                                             unsigned long value)
+{
+        while (first <= last) {
+                const struct exception_table_entry __attribute__((aligned(8))) *mid;
+                long diff;
+
+                mid = (last - first) / 2 + first;
+                diff = mid->insn - value;
+                if (diff == 0)
+                        return mid->fixup;
+                else if (diff < 0)
+                        first = mid + 1;
+                else
+                        last = mid - 1;
+        }
+        return 0;
+} /* end search_one_table() */
+
+/*****************************************************************************/
+/*
+ * see if there's a fixup handler available to deal with a kernel fault
+ */
+unsigned long search_exception_table(unsigned long pc)
+{
+        unsigned long ret = 0;
+
+        /* determine if the fault lay during a memcpy_user or a memset_user */
+        if (__frame->lr == (unsigned long) &__memset_user_error_lr &&
+            (unsigned long) &memset <= pc && pc < (unsigned long) &__memset_end
+            ) {
+                /* the fault occurred in a protected memset
+                 * - we search for the return address (in LR) instead of the program counter
+                 * - it was probably during a clear_user()
+                 */
+                return (unsigned long) &__memset_user_error_handler;
+        }
+        else if (__frame->lr == (unsigned long) &__memcpy_user_error_lr &&
+                 (unsigned long) &memcpy <= pc && pc < (unsigned long) &__memcpy_end
+                 ) {
+                /* the fault occurred in a protected memset
+                 * - we search for the return address (in LR) instead of the program counter
+                 * - it was probably during a copy_to/from_user()
+                 */
+                return (unsigned long) &__memcpy_user_error_handler;
+        }
+
+#ifndef CONFIG_MODULES
+        /* there is only the kernel to search.  */
+        ret = search_one_table(__start___ex_table, __stop___ex_table - 1, pc);
+        return ret;
+
+#else
+        /* the kernel is the last "module" -- no need to treat it special */
+        unsigned long flags;
+        struct module *mp;
+
+        spin_lock_irqsave(&modlist_lock, flags);
+
+        for (mp = module_list; mp != NULL; mp = mp->next) {
+                if (mp->ex_table_start == NULL || !(mp->flags & (MOD_RUNNING | MOD_INITIALIZING)))
+                        continue;
+                ret = search_one_table(mp->ex_table_start, mp->ex_table_end - 1, pc);
+                if (ret)
+                        break;
+        }
+
+        spin_unlock_irqrestore(&modlist_lock, flags);
+        return ret;
+#endif
+} /* end search_exception_table() */