2008-03-21 23:03:05

by Chris Wright

[permalink] [raw]
Subject: [patch 32/76] futex: fix init order

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

From: Thomas Gleixner <[email protected]>

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 <[email protected]>
Acked-by: Ingo Molnar <[email protected]>
Cc: Lennert Buytenhek <[email protected]>
Cc: Riku Voipio <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>
Signed-off-by: Chris Wright <[email protected]>
Signed-off-by: Greg Kroah-Hartman <[email protected]>
---
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);

--