fpga: xilinx: Avoid using local intermediate buffer

Dont use local temporary buffer for printing out the
info instead use directly from memroy. This fixes the
issue of stack corruprion due to local buffer overflow.

Signed-off-by: Siva Durga Prasad Paladugu <sivadur@xilinx.com>
Signed-off-by: Michal Simek <michal.simek@xilinx.com>

drivers/fpga/xilinx.c

@@ -29,7 +29,6 @@ int fpga_loadbitstream(int devnum, char *fpgadata, size_t size,
 {
 	unsigned int length;
 	unsigned int swapsize;
-	char buffer[80];
 	unsigned char *dataptr;
 	unsigned int i;
 	const fpga_desc *desc;
@@ -57,10 +56,8 @@ int fpga_loadbitstream(int devnum, char *fpgadata, size_t size,
 
 	length = (*dataptr << 8) + *(dataptr + 1);
 	dataptr += 2;
-	for (i = 0; i < length; i++)
-		buffer[i] = *dataptr++;
-
-	printf("  design filename = \"%s\"\n", buffer);
+	printf("  design filename = \"%s\"\n", dataptr);
+	dataptr += length;
 
 	/* get part number (identifier, length, string) */
 	if (*dataptr++ != 0x62) {
@@ -71,23 +68,22 @@ int fpga_loadbitstream(int devnum, char *fpgadata, size_t size,
 
 	length = (*dataptr << 8) + *(dataptr + 1);
 	dataptr += 2;
-	for (i = 0; i < length; i++)
-		buffer[i] = *dataptr++;
 
 	if (xdesc->name) {
-		i = (ulong)strstr(buffer, xdesc->name);
+		i = (ulong)strstr((char *)dataptr, xdesc->name);
 		if (!i) {
 			printf("%s: Wrong bitstream ID for this device\n",
 			       __func__);
 			printf("%s: Bitstream ID %s, current device ID %d/%s\n",
-			       __func__, buffer, devnum, xdesc->name);
+			       __func__, dataptr, devnum, xdesc->name);
 			return FPGA_FAIL;
 		}
 	} else {
 		printf("%s: Please fill correct device ID to xilinx_desc\n",
 		       __func__);
 	}
-	printf("  part number = \"%s\"\n", buffer);
+	printf("  part number = \"%s\"\n", dataptr);
+	dataptr += length;
 
 	/* get date (identifier, length, string) */
 	if (*dataptr++ != 0x63) {
@@ -98,9 +94,8 @@ int fpga_loadbitstream(int devnum, char *fpgadata, size_t size,
 
 	length = (*dataptr << 8) + *(dataptr+1);
 	dataptr += 2;
-	for (i = 0; i < length; i++)
-		buffer[i] = *dataptr++;
-	printf("  date = \"%s\"\n", buffer);
+	printf("  date = \"%s\"\n", dataptr);
+	dataptr += length;
 
 	/* get time (identifier, length, string) */
 	if (*dataptr++ != 0x64) {
@@ -111,9 +106,8 @@ int fpga_loadbitstream(int devnum, char *fpgadata, size_t size,
 
 	length = (*dataptr << 8) + *(dataptr+1);
 	dataptr += 2;
-	for (i = 0; i < length; i++)
-		buffer[i] = *dataptr++;
-	printf("  time = \"%s\"\n", buffer);
+	printf("  time = \"%s\"\n", dataptr);
+	dataptr += length;
 
 	/* get fpga data length (identifier, length) */
 	if (*dataptr++ != 0x65) {