Use scope-based memory management for malloc, free, open, close, etc.

If we are using C++, we might as well use scope-based memory management
for these things, cleaner and less error prone. Also removed
unnecessary gotos.

gpt-utils.h

@@ -96,36 +96,32 @@ enum boot_chain { NORMAL_BOOT = 0, BACKUP_BOOT };
 
 struct gpt_disk {
 	//GPT primary header
-	uint8_t *hdr;
+	std::vector<uint8_t> hdr;
 	//primary header crc
-	uint32_t hdr_crc;
+	uint32_t hdr_crc = 0;
 	//GPT backup header
-	uint8_t *hdr_bak;
+	std::vector<uint8_t> hdr_bak;
 	//backup header crc
-	uint32_t hdr_bak_crc;
+	uint32_t hdr_bak_crc = 0;
 	//Partition entries array
-	uint8_t *pentry_arr;
+	std::vector<uint8_t> pentry_arr;
 	//Partition entries array for backup table
-	uint8_t *pentry_arr_bak;
+	std::vector<uint8_t> pentry_arr_bak;
 	//Size of the pentry array
-	uint32_t pentry_arr_size;
+	uint32_t pentry_arr_size = 0;
 	//Size of each element in the pentry array
-	uint32_t pentry_size;
+	uint32_t pentry_size = 0;
 	//CRC of the partition entry array
-	uint32_t pentry_arr_crc;
+	uint32_t pentry_arr_crc = 0;
 	//CRC of the backup partition entry array
-	uint32_t pentry_arr_bak_crc;
+	uint32_t pentry_arr_bak_crc = 0;
 	//Path to block dev representing the disk
-	char devpath[PATH_MAX];
+	char devpath[PATH_MAX] = { 0 };
 	//Block size of disk
-	uint32_t block_size;
-	uint32_t is_initialized;
+	uint32_t block_size = 0;
+	uint32_t is_initialized = 0;
 };
 
-//GPT disk methods
-struct gpt_disk *gpt_disk_alloc();
-//Free previously allocated gpt_disk struct
-void gpt_disk_free(struct gpt_disk *disk);
 //Get the details of the disk holding the partition whose name
 //is passed in via dev
 int gpt_disk_get_disk_info(const char *dev, struct gpt_disk *disk);

qbootctl.cpp

@@ -41,17 +41,23 @@ bool isslotnum(const char* str)
 	return strspn(str, "01") == strlen(str);
 }
 
+static void unexpectedSlot(const char *arg)
+{
+	fprintf(stderr, "Expected slot not '%s'\n", arg);
+	exit(1);
+}
+
 unsigned parseSlot(const char* arg)
 {
 	char *end;
 	int slot;
-	if (!isslot(arg)) {
-		goto fail;
-	}
+	if (!isslot(arg))
+		unexpectedSlot(arg);
+
 	if (isslotnum(arg)) {
 		slot = (int)strtol(arg, &end, 10);
 		if (end == arg)
-			goto fail;
+			unexpectedSlot(arg);
 	} else {
 		switch (arg[0]) {
 		case 'a':
@@ -63,17 +69,11 @@ unsigned parseSlot(const char* arg)
 			slot = 1;
 			break;
 		default:
-			goto fail;
+			unexpectedSlot(arg);
 		}
 	}
 
 	return (unsigned)slot;
-
-fail:
-	fprintf(stderr,
-		"Expected slot not '%s'\n",
-		arg);
-	exit(1);
 }
 
 int usage()

ufs-bsg.cpp

@@ -48,34 +48,43 @@
 /* UFS BSG device node */
 static char ufs_bsg_dev[FNAME_SZ] = "/dev/bsg/ufs-bsg0";
 
-static int fd_ufs_bsg = 0;
+struct fd_ufs_bsg {
+	int fd = 0;
+
+	~fd_ufs_bsg()
+	{
+		close();
+	}
+
+	void close()
+	{
+		if (fd > 0) {
+			::close(fd);
+			fd = 0;
+		}
+	}
+};
+
+static fd_ufs_bsg fd_ufs_bsg;
 
 int ufs_bsg_dev_open()
 {
-	if (fd_ufs_bsg)
+	if (fd_ufs_bsg.fd)
 		return 0;
 
-	fd_ufs_bsg = open(ufs_bsg_dev, O_RDWR);
-	if (fd_ufs_bsg < 0) {
+	fd_ufs_bsg.fd = open(ufs_bsg_dev, O_RDWR);
+	if (fd_ufs_bsg.fd < 0) {
 		fprintf(stderr, "Unable to open '%s': %s\n", ufs_bsg_dev,
 			strerror(errno));
 		fprintf(stderr,
 			"Is CONFIG_SCSI_UFS_BSG is enabled in your kernel?\n");
-		fd_ufs_bsg = 0;
+		fd_ufs_bsg.fd = 0;
 		return -1;
 	}
 
 	return 0;
 }
 
-void ufs_bsg_dev_close()
-{
-	if (fd_ufs_bsg) {
-		close(fd_ufs_bsg);
-		fd_ufs_bsg = 0;
-	}
-}
-
 static int ufs_bsg_ioctl(int fd, struct ufs_bsg_request *req,
 			 struct ufs_bsg_reply *rsp, __u8 *buf, __u32 buf_len,
 			 enum bsg_ioctl_dir dir)
@@ -171,18 +180,18 @@ int32_t set_boot_lun(__u8 lun_id)
 	ret = ufs_bsg_dev_open();
 	if (ret)
 		return ret;
+
 	LOGD("Opened ufs bsg dev: %s\n", ufs_bsg_dev);
 
-	ret = ufs_query_attr(fd_ufs_bsg, boot_lun_id, QUERY_REQ_FUNC_STD_WRITE,
-			     QUERY_REQ_OP_WRITE_ATTR, QUERY_ATTR_IDN_BOOT_LU_EN,
-			     0, 0);
+	ret = ufs_query_attr(fd_ufs_bsg.fd, boot_lun_id,
+			     QUERY_REQ_FUNC_STD_WRITE, QUERY_REQ_OP_WRITE_ATTR,
+			     QUERY_ATTR_IDN_BOOT_LU_EN, 0, 0);
 	if (ret) {
 		fprintf(stderr,
 			"Error requesting ufs attr idn %d via query ioctl (return value: %d, error no: %d)",
 			QUERY_ATTR_IDN_BOOT_LU_EN, ret, errno);
-		goto out;
 	}
-out:
-	ufs_bsg_dev_close();
+
+	fd_ufs_bsg.close();
 	return ret;
 }