diff --git a/devicemodel/hw/pci/virtio/rpmb_backend.c b/devicemodel/hw/pci/virtio/rpmb_backend.c
index e70789a64..95df38490 100644
--- a/devicemodel/hw/pci/virtio/rpmb_backend.c
+++ b/devicemodel/hw/pci/virtio/rpmb_backend.c
@@ -42,13 +42,15 @@ static int virtio_rpmb_debug = 1;
 #define DPRINTF(params) do { if (virtio_rpmb_debug) printf params; } while (0)
 #define WPRINTF(params) (printf params)
 
+#define READ_STR_LEN 10
+#define WRITE_STR_LEN 11
 static uint32_t phy_counter = 0;
 static uint32_t virt_counter = 0;
 static uint8_t rpmb_key[RPMB_KEY_32_LEN] = {0};
 static uint8_t virt_rpmb_key[RPMB_KEY_32_LEN] = {0};
 static uint16_t g_rpmb_mode = RPMB_SIM_MODE;
-static const char READ_DATA_STR[] = "read data";
-static const char WRITE_DATA_STR[] = "write data";
+static const char READ_DATA_STR[READ_STR_LEN] = "read data";
+static const char WRITE_DATA_STR[WRITE_STR_LEN] = "write data";
 
 //TODO: will be read from config file.
 static uint16_t get_uos_count(void)
diff --git a/devicemodel/hw/pci/virtio/rpmb_sim.c b/devicemodel/hw/pci/virtio/rpmb_sim.c
index f5b810d4d..2e44391b6 100644
--- a/devicemodel/hw/pci/virtio/rpmb_sim.c
+++ b/devicemodel/hw/pci/virtio/rpmb_sim.c
@@ -133,7 +133,7 @@ static void rpmb_sim_close(void)
 	rpmb_fd = NULL;
 }
 
-static size_t file_write(FILE *fp, const void *buf, size_t size, off_t offset)
+static int file_write(FILE *fp, const void *buf, size_t size, off_t offset)
 {
 	size_t rc = 0;
 
@@ -147,15 +147,14 @@ static size_t file_write(FILE *fp, const void *buf, size_t size, off_t offset)
 		return -1;
 	}
 
-	rc = fflush(fp);
-	if (rc < 0) {
-	return -1;
-	} else {
-		return 0;
+	if (fflush(fp) < 0) {
+		return -1;
 	}
+
+	return rc;
 }
 
-static size_t file_read(FILE *fp, void *buf, size_t size, off_t offset)
+static int file_read(FILE *fp, void *buf, size_t size, off_t offset)
 {
 	size_t rc = 0;