[PATCH 1/2] futex: fix init order

From: Thomas Gleixner
Date: Thu Feb 14 2008 - 20:24:22 EST


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>

---
kernel/futex.c | 12 +++++++-----
1 file changed, 7 insertions(+), 5 deletions(-)

Index: linux-2.6/kernel/futex.c
===================================================================
--- linux-2.6.orig/kernel/futex.c
+++ linux-2.6/kernel/futex.c
@@ -2145,8 +2145,14 @@ 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;

@@ -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);
--
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