From: Thomas Gleixner <tglx@linutronix.de>
Date: Sat, 23 Feb 2008 23:23:55 +0000 (-0800)
Subject: futex: fix init order
X-Git-Tag: v2.6.25-rc3~36
X-Git-Url: https://err.no/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=3e4ab747efa8e78562ec6782b08bbf21a00aba1b;p=linux-2.6

futex: fix init order

When the futex init code fails to initialize the futex pseudo file system it
returns early without initializing the hash queues.  Should the boot succeed
then a futex syscall which tries to enqueue a waiter on the hashqueue will
crash due to the unitilialized plist heads.

Initialize the hash queues before the filesystem.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Ingo Molnar <mingo@elte.hu>
Cc: Lennert Buytenhek <buytenh@wantstofly.org>
Cc: Riku Voipio <riku.voipio@movial.fi>
Cc: <stable@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
---

diff --git a/kernel/futex.c b/kernel/futex.c
index 221f2128a4..c21f667c63 100644
--- a/kernel/futex.c
+++ b/kernel/futex.c
@@ -2145,8 +2145,14 @@ static struct file_system_type futex_fs_type = {
 
 static int __init init(void)
 {
-	int i = register_filesystem(&futex_fs_type);
+	int i;
 
+	for (i = 0; i < ARRAY_SIZE(futex_queues); i++) {
+		plist_head_init(&futex_queues[i].chain, &futex_queues[i].lock);
+		spin_lock_init(&futex_queues[i].lock);
+	}
+
+	i = register_filesystem(&futex_fs_type);
 	if (i)
 		return i;
 
@@ -2156,10 +2162,6 @@ static int __init init(void)
 		return PTR_ERR(futex_mnt);
 	}
 
-	for (i = 0; i < ARRAY_SIZE(futex_queues); i++) {
-		plist_head_init(&futex_queues[i].chain, &futex_queues[i].lock);
-		spin_lock_init(&futex_queues[i].lock);
-	}
 	return 0;
 }
 __initcall(init);