From b591b6e9e99017137888e2e397f0ddd8adb77c5d Mon Sep 17 00:00:00 2001
From: Takashi Iwai <tiwai@suse.de>
Date: Wed, 22 Apr 2015 22:29:10 +0200
Subject: ALSA: core: Don't ignore errors at creating proc files

So far we've ignored the errors at creating proc files in many places.
But they should be rather treated seriously.

Also, by assuring the error handling, we can get rid of superfluous
snd_info_free_entry() calls as they will be removed by the parent in
the caller side.

This patch fixes the missing error checks and reduces the superfluous
free calls.

Acked-by: Jaroslav Kysela <perex@perex.cz>
Signed-off-by: Takashi Iwai <tiwai@suse.de>

diff --git a/sound/core/info.c b/sound/core/info.c
index 339f90a..4169062 100644
--- a/sound/core/info.c
+++ b/sound/core/info.c
@@ -482,10 +482,11 @@ int __init snd_info_init(void)
 	if (!snd_seq_root)
 		goto error;
 #endif
-	snd_info_version_init();
-	snd_minor_info_init();
-	snd_minor_info_oss_init();
-	snd_card_info_init();
+	if (snd_info_version_init() < 0 ||
+	    snd_minor_info_init() < 0 ||
+	    snd_minor_info_oss_init() < 0 ||
+	    snd_card_info_init() < 0)
+		goto error;
 	return 0;
 
  error:
@@ -847,11 +848,7 @@ static int __init snd_info_version_init(void)
 	if (entry == NULL)
 		return -ENOMEM;
 	entry->c.text.read = snd_info_version_read;
-	if (snd_info_register(entry) < 0) {
-		snd_info_free_entry(entry);
-		return -ENOMEM;
-	}
-	return 0;
+	return snd_info_register(entry); /* freed in error path */
 }
 
 #endif /* CONFIG_PROC_FS */
diff --git a/sound/core/init.c b/sound/core/init.c
index 0af34fa..769a783 100644
--- a/sound/core/init.c
+++ b/sound/core/init.c
@@ -853,18 +853,16 @@ int __init snd_card_info_init(void)
 	if (! entry)
 		return -ENOMEM;
 	entry->c.text.read = snd_card_info_read;
-	if (snd_info_register(entry) < 0) {
-		snd_info_free_entry(entry);
-		return -ENOMEM;
-	}
+	if (snd_info_register(entry) < 0)
+		return -ENOMEM; /* freed in error path */
 
 #ifdef MODULE
 	entry = snd_info_create_module_entry(THIS_MODULE, "modules", NULL);
-	if (entry) {
-		entry->c.text.read = snd_card_module_info_read;
-		if (snd_info_register(entry) < 0)
-			snd_info_free_entry(entry);
-	}
+	if (!entry)
+		return -ENOMEM;
+	entry->c.text.read = snd_card_module_info_read;
+	if (snd_info_register(entry) < 0)
+		return -ENOMEM; /* freed in error path */
 #endif
 
 	return 0;
diff --git a/sound/core/seq/seq_info.c b/sound/core/seq/seq_info.c
index acf7769..d3c65e7 100644
--- a/sound/core/seq/seq_info.c
+++ b/sound/core/seq/seq_info.c
@@ -51,6 +51,13 @@ create_info_entry(char *name, void (*read)(struct snd_info_entry *,
 	return entry;
 }
 
+static void free_info_entries(void)
+{
+	snd_info_free_entry(queues_entry);
+	snd_info_free_entry(clients_entry);
+	snd_info_free_entry(timer_entry);
+}
+
 /* create all our /proc entries */
 int __init snd_seq_info_init(void)
 {
@@ -59,14 +66,18 @@ int __init snd_seq_info_init(void)
 	clients_entry = create_info_entry("clients",
 					  snd_seq_info_clients_read);
 	timer_entry = create_info_entry("timer", snd_seq_info_timer_read);
+	if (!queues_entry || !clients_entry || !timer_entry)
+		goto error;
 	return 0;
+
+ error:
+	free_info_entries();
+	return -ENOMEM;
 }
 
 int __exit snd_seq_info_done(void)
 {
-	snd_info_free_entry(queues_entry);
-	snd_info_free_entry(clients_entry);
-	snd_info_free_entry(timer_entry);
+	free_info_entries();
 	return 0;
 }
 #endif
diff --git a/sound/core/sound.c b/sound/core/sound.c
index d584944..8fc402e 100644
--- a/sound/core/sound.c
+++ b/sound/core/sound.c
@@ -386,14 +386,10 @@ int __init snd_minor_info_init(void)
 	struct snd_info_entry *entry;
 
 	entry = snd_info_create_module_entry(THIS_MODULE, "devices", NULL);
-	if (entry) {
-		entry->c.text.read = snd_minor_info_read;
-		if (snd_info_register(entry) < 0) {
-			snd_info_free_entry(entry);
-			entry = NULL;
-		}
-	}
-	return 0;
+	if (!entry)
+		return -ENOMEM;
+	entry->c.text.read = snd_minor_info_read;
+	return snd_info_register(entry); /* freed in error path */
 }
 #endif /* CONFIG_PROC_FS */
 
diff --git a/sound/core/sound_oss.c b/sound/core/sound_oss.c
index 5fc3c65..56d2f40 100644
--- a/sound/core/sound_oss.c
+++ b/sound/core/sound_oss.c
@@ -260,12 +260,10 @@ int __init snd_minor_info_oss_init(void)
 	struct snd_info_entry *entry;
 
 	entry = snd_info_create_module_entry(THIS_MODULE, "devices", snd_oss_root);
-	if (entry) {
-		entry->c.text.read = snd_minor_info_oss_read;
-		if (snd_info_register(entry) < 0)
-			snd_info_free_entry(entry);
-	}
-	return 0;
+	if (!entry)
+		return -ENOMEM;
+	entry->c.text.read = snd_minor_info_oss_read;
+	return snd_info_register(entry); /* freed in error path */
 }
 #endif /* CONFIG_PROC_FS */
 
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