Re: lock-up with module: Optimize __module_address() using a latched RB-tree

[Arthur Marsh <arthur.marsh@internode.on.net>]

Peter Zijlstra wrote on 08/07/15 07:41:
> On Tue, Jul 07, 2015 at 11:56:20PM +0200, Peter Zijlstra wrote:

> Could you try the below? It appears there was a spot freeing modules
> that forgot to take them out of the tree.
>
> If that fails, try and disable CONFIG_MODULE_UNLOAD.

I tried the patch below, re-built and installed and booted the kernel 
and saw:

http://www.users.on.net/~arthur.marsh/20150708471.jpg
http://www.users.on.net/~arthur.marsh/20150708472.jpg

I'm now rebuilding the kernel with CONFIG_MODULE_UNLOAD disabled.

Arthur.

>
> ---
>   kernel/module.c | 1 +
>   1 file changed, 1 insertion(+)
>
> diff --git a/kernel/module.c b/kernel/module.c
> index 3e0e19763d24..4d2b82e610e2 100644
> --- a/kernel/module.c
> +++ b/kernel/module.c
> @@ -3557,6 +3557,7 @@ static int load_module(struct load_info *info, const char __user *uargs,
>   	mutex_lock(&module_mutex);
>   	/* Unlink carefully: kallsyms could be walking list. */
>   	list_del_rcu(&mod->list);
> +	mod_tree_remove(mod);
>   	wake_up_all(&module_wq);
>   	/* Wait for RCU-sched synchronizing before releasing mod->list. */
>   	synchronize_sched();
>