[Feature]add MT2731_MP2_MR2_SVN388 baseline version

Change-Id: Ief04314834b31e27effab435d3ca8ba33b499059
diff --git a/src/kernel/linux/v4.14/arch/frv/mm/extable.c b/src/kernel/linux/v4.14/arch/frv/mm/extable.c
new file mode 100644
index 0000000..77c0c5b
--- /dev/null
+++ b/src/kernel/linux/v4.14/arch/frv/mm/extable.c
@@ -0,0 +1,49 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * linux/arch/frv/mm/extable.c
+ */
+
+#include <linux/extable.h>
+#include <linux/spinlock.h>
+#include <linux/uaccess.h>
+
+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;
+
+int fixup_exception(struct pt_regs *regs)
+{
+	const struct exception_table_entry *extab;
+	unsigned long pc = regs->pc;
+
+	/* determine if the fault lay during a memcpy_user or a memset_user */
+	if (regs->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()
+		 */
+		regs->pc = (unsigned long) &__memset_user_error_handler;
+		return 1;
+	}
+
+	if (regs->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()
+		 */
+		regs->pc = (unsigned long) &__memcpy_user_error_handler;
+		return 1;
+	}
+
+	extab = search_exception_tables(pc);
+	if (extab) {
+		regs->pc = extab->fixup;
+		return 1;
+	}
+
+	return 0;
+}