[PATCH 3/4] bootsource: have bootsource_get_alias_name return const char *

[Ahmad Fatoum]

The only user of bootsource_get_alias_name() calls it and frees it
shortly after and users in board code will likely do the same.

Instead of allocating every time, let's just return a static array and
expect users to call strdup() if they want to keep the bootsource valid
for longer.

Signed-off-by: Ahmad Fatoum <a.fatoum at pengutronix.de>
---
 common/bootsource.c  | 23 +++++++++++------------
 include/bootsource.h |  2 +-
 2 files changed, 12 insertions(+), 13 deletions(-)

diff --git a/common/bootsource.c b/common/bootsource.c
index 6808c9c51d88..3c8f53f3a890 100644
--- a/common/bootsource.c
+++ b/common/bootsource.c
@@ -72,27 +72,24 @@ const char *bootsource_get_alias_stem(enum bootsource src)
 /**
  * bootsource_get_alias_name() - Get the name of the bootsource alias
  *
- * This function will return newly allocated string containing name of
+ * This function will return a pointer to a static string containing name of
  * the alias that is expected to point to DTB node corresponding to
  * detected bootsource
  *
- * NOTE: Caller is expected to free() the string allocated by this
- * function
  */
-char *bootsource_get_alias_name(void)
+const char *bootsource_get_alias_name(void)
 {
+	static char buf[sizeof("i2c-eeprom-2147483647")];
 	const char *stem;
+	int ret;
 
 	/*
 	 * If alias name was overridden via
 	 * bootsource_set_alias_name() return that value without
 	 * asking any questions.
-	 *
-	 * Note that we have to strdup() the result to make it
-	 * free-able.
 	 */
 	if (bootsource_alias_name)
-		return strdup(bootsource_alias_name);
+		return bootsource_alias_name;
 
 	stem = bootsource_get_alias_stem(bootsource);
 	if (!stem)
@@ -105,13 +102,17 @@ char *bootsource_get_alias_name(void)
 	if (bootsource_instance == BOOTSOURCE_INSTANCE_UNKNOWN)
 		return NULL;
 
-	return basprintf("%s%d", stem, bootsource_instance);
+	ret = snprintf(buf, sizeof(buf), "%s%d", stem, bootsource_instance);
+	if (ret < 0 || ret >= sizeof(buf))
+		return NULL;
+
+	return buf;
 }
 
 struct device_node *bootsource_of_node_get(struct device_node *root)
 {
 	struct device_node *np;
-	char *alias_name;
+	const char *alias_name;
 
 	alias_name = bootsource_get_alias_name();
 	if (!alias_name)
@@ -119,8 +120,6 @@ struct device_node *bootsource_of_node_get(struct device_node *root)
 
 	np = of_find_node_by_alias(root, alias_name);
 
-	free(alias_name);
-
 	return np;
 }
 
diff --git a/include/bootsource.h b/include/bootsource.h
index 33ad26946059..9fb77a0bb0a9 100644
--- a/include/bootsource.h
+++ b/include/bootsource.h
@@ -29,7 +29,7 @@ enum bootsource bootsource_get(void);
 enum bootsource bootsource_get_device(void);
 int bootsource_get_instance(void);
 void bootsource_set_alias_name(const char *name);
-char *bootsource_get_alias_name(void);
+const char *bootsource_get_alias_name(void);
 const char *bootsource_to_string(enum bootsource src);
 const char *bootsource_get_alias_stem(enum bootsource bs);
 int bootsource_of_alias_xlate(enum bootsource bs, int instance);
-- 
2.39.5