Re: 2.6.23-rc6-mm1: IPC: sleeping function called ...

[Alexey Dobriyan <adobriyan@sw.ru>]

On Tue, Sep 18, 2007 at 03:27:27AM -0700, Andrew Morton wrote:
> On Tue, 18 Sep 2007 13:17:28 +0400 Alexey Dobriyan <adobriyan@sw.ru> wrote:
> 
> > I'm getting tons of this, and X fails to start
> > 
> > CONFIG_SYSVIPC=y
> > CONFIG_SYSVIPC_SYSCTL=y
> > # CONFIG_PREEMPT_NONE is not set
> > # CONFIG_PREEMPT_VOLUNTARY is not set
> > CONFIG_PREEMPT=y
> > CONFIG_PREEMPT_BKL=y
> > CONFIG_DEBUG_PREEMPT=y
> > 
> > BUG: sleeping function called from invalid context at kernel/rwsem.c:47
> > in_atomic():1, irqs_disabled():0
> 
> OK, this fixes the locking here:

Ditto. Thanks!
[puts mental note to read IPC patches]

> --- a/ipc/util.c~ipc-integrate-ipc_checkid-into-ipc_lock-fix-2
> +++ a/ipc/util.c
> @@ -295,7 +295,6 @@ int ipc_addid(struct ipc_ids* ids, struc
>  
>  	spin_lock_init(&new->lock);
>  	new->deleted = 0;
> -	rcu_read_lock();
>  	spin_lock(&new->lock);
>  	return id;
>  }
> @@ -691,7 +690,7 @@ struct kern_ipc_perm *ipc_lock(struct ip
>  		rcu_read_unlock();
>  		return ERR_PTR(-EINVAL);
>  	}
> -
> +	rcu_read_unlock();
>  	return out;
>  }