add MCEXEC_UP_STRNCPY_FROM_USER

It allows a mcexec to execute the strncpy_from_user().

executer/include/uprotocol.h

@@ -37,6 +37,7 @@
 #define MCEXEC_UP_LOAD_SYSCALL   0x30a02905
 #define MCEXEC_UP_SEND_SIGNAL    0x30a02906
 #define MCEXEC_UP_GET_CPU        0x30a02907
+#define MCEXEC_UP_STRNCPY_FROM_USER 0x30a02908
 
 #define MCEXEC_UP_PREPARE_DMA    0x30a02910
 #define MCEXEC_UP_FREE_DMA       0x30a02911
@@ -115,6 +116,13 @@ struct syscall_ret_desc {
 	unsigned long size;
 };
 
+struct strncpy_from_user_desc {
+	void *dest;
+	void *src;
+	unsigned long n;
+	long result;
+};
+
 struct prepare_dma_desc {
 	unsigned long size;
 	unsigned long pa;