On Thu, 8 Feb 2007 11:35:39 +0300 Oleg Nesterov <[EMAIL PROTECTED]> wrote:
> On 02/08, Horms wrote: > > > > On Wed, Feb 07, 2007 at 08:43:55PM +0300, Oleg Nesterov wrote: > > > > > > I think we have another problem with delayed_works. > > > > > > cancel_rearming_delayed_workqueue() doesn't garantee that the ->func() is > > > not > > > running upon return. I don't know if it is bug or not, the comment says > > > nothing > > > about that. > > > > > > However, we have the callers which seem to assume the opposite, example > > > > > > net/ipv4/ipvs/ip_vs_core.c > > > > > > module_exit > > > ip_vs_cleanup > > > ip_vs_control_cleanup > > > cancel_rearming_delayed_work > > > // done > > > > > > This is unsafe. The module may be unloaded and the memory may be freed > > > while defense_work_handler() is still running/preempted. > > > > > > Unless I missed something, which side should be fixed? > > > > Assuming the decision is to fix the ipvs side, is the fix > > just to remove the call to cancel_rearming_delayed_work() in > > ip_vs_control_cleanup() ? > > I think ip_vs_control_cleanup() should also do flush_workqueue() after > cancel_rearming_delayed_work(). > > This is ugly, because we have flush_work() but can't use it on delayed > works. This is possible to change, but not so trivial. > > Andrew, do you think it is worth to tweak delayed works so it would be > possible to use flush_work(dwork->work) ? > I've completely lost track of what you've been doing in there (this is a problem) but sure, if the patch isn't too horrid it's always better to be robust in the core than to have to work around inadequacies in the callers. - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
