[patch 32/76] futex: fix init order

[Chris Wright]

-stable review patch.  If anyone has any objections, please let us know.
---------------------

From: Thomas Gleixner <tglx@xxxxxxxxxxxxx>

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@xxxxxxxxxxxxx>
Acked-by: Ingo Molnar <mingo@xxxxxxx>
Cc: Lennert Buytenhek <buytenh@xxxxxxxxxxxxxx>
Cc: Riku Voipio <riku.voipio@xxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
Signed-off-by: Linus Torvalds <torvalds@xxxxxxxxxxxxxxxxxxxx>
Signed-off-by: Chris Wright <chrisw@xxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxx>
---
 kernel/futex.c |   12 +++++++-----
 1 file changed, 7 insertions(+), 5 deletions(-)

--- a/kernel/futex.c
+++ b/kernel/futex.c
@@ -2123,8 +2123,14 @@ static struct file_system_type futex_fs_
 
 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;
 
@@ -2134,10 +2140,6 @@ 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);

-- 
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/