Re: [patch] drivers: wait for threaded probes between initcall levels

[Greg KH <greg@kroah.com>]

On Fri, Oct 27, 2006 at 01:48:54PM -0700, Linus Torvalds wrote:
> 
> 
> On Fri, 27 Oct 2006, Linus Torvalds wrote:
> 
> > 
> > 	static int do_in_parallel(void *arg)
> > 	{
> > 		struct thread_exec *p = arg;
> > 		int (*fn)(void *) = p->fn;
> > 		void *arg = p->arg;
> > 		int retval;
> > 
> > 		/* Tell the caller we are done with the arguments */
> > 		complete(&p->completion);
> > 
> > 		/* Do the actual work in parallel */
> > 		retval = p->fn(p->arg);
> 
> Duh. The whole reason I copied them was to _not_ do that. That last line 
> should obviously be
> 
> 		retval = fn(arg);
> 
> because "p" may gone after we've done the "complete()".
> 
> > (And I repeat: the above code is untested, and was written in the email 
> > client. It has never seen a compiler, and not gotten a _whole_ lot of 
> > thinking).
> 
> .. This hasn't changed, I just looked through the code once and found that 
> obvious bug.

Heh, ok, I'll take this idea, and Andrew's patch, and rework things for
the next round of 2.6.20-rc kernels, and mark the current stuff as
BROKEN for now.

thanks,

greg k-h
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