eficonfig: carve out efi_get_next_variable_name_int calls

To retrieve the EFI variable name by efi_get_next_variable_name_int(),
the sequence of alloc -> efi_get_next_variable_name_int ->
realloc -> efi_get_next_variable_name_int is required.
In current code, this sequence repeatedly appears in
the several functions. It should be curved out a common function.

This commit also fixes the missing free() of var_name16
in eficonfig_delete_invalid_boot_option().

Signed-off-by: Masahisa Kojima <masahisa.kojima@linaro.org>
Reviewed-by: Heinrich Schuchardt <heinrich.schuchardt@canonical.com>
Reviewed-by: Ilias Apalodimas <ilias.apalodimas@linaro.org>

cmd/eficonfig.c

@@ -1683,7 +1683,7 @@ static efi_status_t eficonfig_show_boot_selection(unsigned int *selected)
 	u32 i;
 	u16 *bootorder;
 	efi_status_t ret;
-	u16 *var_name16 = NULL, *p;
+	u16 *var_name16 = NULL;
 	efi_uintn_t num, size, buf_size;
 	struct efimenu *efi_menu;
 	struct list_head *pos, *n;
@@ -1718,24 +1718,12 @@ static efi_status_t eficonfig_show_boot_selection(unsigned int *selected)
 		int index;
 		efi_guid_t guid;
 
-		size = buf_size;
+		ret = efi_next_variable_name(&buf_size, &var_name16, &guid);
-		ret = efi_get_next_variable_name_int(&size, var_name16, &guid);
 		if (ret == EFI_NOT_FOUND)
 			break;
-		if (ret == EFI_BUFFER_TOO_SMALL) {
+		if (ret != EFI_SUCCESS)
-			buf_size = size;
+			goto out;
-			p = realloc(var_name16, buf_size);
+
-			if (!p) {
-				free(var_name16);
-				return EFI_OUT_OF_RESOURCES;
-			}
-			var_name16 = p;
-			ret = efi_get_next_variable_name_int(&size, var_name16, &guid);
-		}
-		if (ret != EFI_SUCCESS) {
-			free(var_name16);
-			return ret;
-		}
 		if (efi_varname_is_load_option(var_name16, &index)) {
 			/* If the index is included in the BootOrder, skip it */
 			if (search_bootorder(bootorder, num, index, NULL))
@@ -2026,7 +2014,7 @@ static efi_status_t eficonfig_create_change_boot_order_entry(struct efimenu *efi
 	u32 i;
 	char *title;
 	efi_status_t ret;
-	u16 *var_name16 = NULL, *p;
+	u16 *var_name16 = NULL;
 	efi_uintn_t size, buf_size;
 
 	/* list the load option in the order of BootOrder variable */
@@ -2054,19 +2042,9 @@ static efi_status_t eficonfig_create_change_boot_order_entry(struct efimenu *efi
 			break;
 
 		size = buf_size;
-		ret = efi_get_next_variable_name_int(&size, var_name16, &guid);
+		ret = efi_next_variable_name(&buf_size, &var_name16, &guid);
 		if (ret == EFI_NOT_FOUND)
 			break;
-		if (ret == EFI_BUFFER_TOO_SMALL) {
-			buf_size = size;
-			p = realloc(var_name16, buf_size);
-			if (!p) {
-				ret = EFI_OUT_OF_RESOURCES;
-				goto out;
-			}
-			var_name16 = p;
-			ret = efi_get_next_variable_name_int(&size, var_name16, &guid);
-		}
 		if (ret != EFI_SUCCESS)
 			goto out;
 
@@ -2336,10 +2314,10 @@ efi_status_t eficonfig_delete_invalid_boot_option(struct eficonfig_media_boot_op
 	efi_uintn_t size;
 	void *load_option;
 	struct efi_load_option lo;
-	u16 *var_name16 = NULL, *p;
+	u16 *var_name16 = NULL;
 	u16 varname[] = u"Boot####";
 	efi_status_t ret = EFI_SUCCESS;
-	efi_uintn_t varname_size, buf_size;
+	efi_uintn_t buf_size;
 
 	buf_size = 128;
 	var_name16 = malloc(buf_size);
@@ -2352,24 +2330,12 @@ efi_status_t eficonfig_delete_invalid_boot_option(struct eficonfig_media_boot_op
 		efi_guid_t guid;
 		efi_uintn_t tmp;
 
-		varname_size = buf_size;
+		ret = efi_next_variable_name(&buf_size, &var_name16, &guid);
-		ret = efi_get_next_variable_name_int(&varname_size, var_name16, &guid);
 		if (ret == EFI_NOT_FOUND)
 			break;
-		if (ret == EFI_BUFFER_TOO_SMALL) {
+		if (ret != EFI_SUCCESS)
-			buf_size = varname_size;
+			goto out;
-			p = realloc(var_name16, buf_size);
+
-			if (!p) {
-				free(var_name16);
-				return EFI_OUT_OF_RESOURCES;
-			}
-			var_name16 = p;
-			ret = efi_get_next_variable_name_int(&varname_size, var_name16, &guid);
-		}
-		if (ret != EFI_SUCCESS) {
-			free(var_name16);
-			return ret;
-		}
 		if (!efi_varname_is_load_option(var_name16, &index))
 			continue;
 
@@ -2407,6 +2373,8 @@ next:
 	}
 
 out:
+	free(var_name16);
+
 	return ret;
 }
 

include/efi_loader.h

@@ -708,6 +708,8 @@ int algo_to_len(const char *algo);
 int efi_link_dev(efi_handle_t handle, struct udevice *dev);
 int efi_unlink_dev(efi_handle_t handle);
 bool efi_varname_is_load_option(u16 *var_name16, int *index);
+efi_status_t efi_next_variable_name(efi_uintn_t *size, u16 **buf,
+				    efi_guid_t *guid);
 
 /**
  * efi_size_in_pages() - convert size in bytes to size in pages

lib/efi_loader/efi_helper.c

@@ -223,3 +223,37 @@ bool efi_varname_is_load_option(u16 *var_name16, int *index)
 
 	return false;
 }
+
+/**
+ * efi_next_variable_name() - get next variable name
+ *
+ * This function is a wrapper of efi_get_next_variable_name_int().
+ * If efi_get_next_variable_name_int() returns EFI_BUFFER_TOO_SMALL,
+ * @size and @buf are updated by new buffer size and realloced buffer.
+ *
+ * @size:	pointer to the buffer size
+ * @buf:	pointer to the buffer
+ * @guid:	pointer to the guid
+ * Return:	status code
+ */
+efi_status_t efi_next_variable_name(efi_uintn_t *size, u16 **buf, efi_guid_t *guid)
+{
+	u16 *p;
+	efi_status_t ret;
+	efi_uintn_t buf_size = *size;
+
+	ret = efi_get_next_variable_name_int(&buf_size, *buf, guid);
+	if (ret == EFI_NOT_FOUND)
+		return ret;
+	if (ret == EFI_BUFFER_TOO_SMALL) {
+		p = realloc(*buf, buf_size);
+		if (!p)
+			return EFI_OUT_OF_RESOURCES;
+
+		*buf = p;
+		*size = buf_size;
+		ret = efi_get_next_variable_name_int(&buf_size, *buf, guid);
+	}
+
+	return ret;
+}