From: Marek Lindner <lindner_marek@yahoo.de>
Date: Mon, 9 Aug 2010 21:56:39 +0000 (+0200)
Subject: Staging: batman-adv: unify orig_hash_lock spinlock handling to avoid deadlocks
X-Git-Tag: firefly_0821_release~9833^2~665^2~7
X-Git-Url: http://demsky.eecs.uci.edu/git/?a=commitdiff_plain;h=9abc10238e1df7ce81c58a441f65efd5e905b9e8;p=firefly-linux-kernel-4.4.55.git

Staging: batman-adv: unify orig_hash_lock spinlock handling to avoid deadlocks

The orig_hash_lock spinlock always has to be locked with IRQs being
disabled to avoid deadlocks between code that is being executed in
IRQ context and code that is being executed in non-IRQ context.

Reported-by: Sven Eckelmann <sven.eckelmann@gmx.de>
Signed-off-by: Marek Lindner <lindner_marek@yahoo.de>
Signed-off-by: Sven Eckelmann <sven.eckelmann@gmx.de>
Cc: stable <stable@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
---

diff --git a/drivers/staging/batman-adv/originator.c b/drivers/staging/batman-adv/originator.c
index 28bb627ffa13..de5a8c1a8104 100644
--- a/drivers/staging/batman-adv/originator.c
+++ b/drivers/staging/batman-adv/originator.c
@@ -391,11 +391,12 @@ static int orig_node_add_if(struct orig_node *orig_node, int max_if_num)
 int orig_hash_add_if(struct batman_if *batman_if, int max_if_num)
 {
 	struct orig_node *orig_node;
+	unsigned long flags;
 	HASHIT(hashit);
 
 	/* resize all orig nodes because orig_node->bcast_own(_sum) depend on
 	 * if_num */
-	spin_lock(&orig_hash_lock);
+	spin_lock_irqsave(&orig_hash_lock, flags);
 
 	while (hash_iterate(orig_hash, &hashit)) {
 		orig_node = hashit.bucket->data;
@@ -404,11 +405,11 @@ int orig_hash_add_if(struct batman_if *batman_if, int max_if_num)
 			goto err;
 	}
 
-	spin_unlock(&orig_hash_lock);
+	spin_unlock_irqrestore(&orig_hash_lock, flags);
 	return 0;
 
 err:
-	spin_unlock(&orig_hash_lock);
+	spin_unlock_irqrestore(&orig_hash_lock, flags);
 	return -ENOMEM;
 }
 
@@ -468,12 +469,13 @@ int orig_hash_del_if(struct batman_if *batman_if, int max_if_num)
 {
 	struct batman_if *batman_if_tmp;
 	struct orig_node *orig_node;
+	unsigned long flags;
 	HASHIT(hashit);
 	int ret;
 
 	/* resize all orig nodes because orig_node->bcast_own(_sum) depend on
 	 * if_num */
-	spin_lock(&orig_hash_lock);
+	spin_lock_irqsave(&orig_hash_lock, flags);
 
 	while (hash_iterate(orig_hash, &hashit)) {
 		orig_node = hashit.bucket->data;
@@ -500,10 +502,10 @@ int orig_hash_del_if(struct batman_if *batman_if, int max_if_num)
 	rcu_read_unlock();
 
 	batman_if->if_num = -1;
-	spin_unlock(&orig_hash_lock);
+	spin_unlock_irqrestore(&orig_hash_lock, flags);
 	return 0;
 
 err:
-	spin_unlock(&orig_hash_lock);
+	spin_unlock_irqrestore(&orig_hash_lock, flags);
 	return -ENOMEM;
 }