Messages in this thread |  | | | Date | Thu, 23 Nov 2006 10:47:55 +0100 | | From | Sébastien Dugué <> | | Subject | Re: [PATCH -mm 3/4][AIO] - AIO completion signal notification |
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On Thu, 23 Nov 2006 00:40:53 -0800 Andrew Morton <akpm@osdl.org> wrote:
> On Thu, 23 Nov 2006 09:28:05 +0100 > Sébastien Dugué <sebastien.dugue@bull.net> wrote: > > > > > + target = good_sigevent(&event); > > > > + > > > > + if (unlikely(!target || (target->flags & PF_EXITING))) > > > > + goto out_unlock; > > > > + > > > > + > > > > + > > > > + if (notify->notify == (SIGEV_SIGNAL|SIGEV_THREAD_ID)) { > > > > + /* > > > > + * This reference will be dropped in really_put_req() when > > > > + * we're done with the request. > > > > + */ > > > > + get_task_struct(target); > > > > + } > > > > > > It worries me that this function can save away a task_struct* without > > > having taken a reference against it. > > > > > > > OK. Does moving 'notify->target = target;' after the get_task_struct() will > > do, or am I missing something more subtle? > > Well it's your code - you tell me ;) > > It is unsafe (and rather pointless) to be saving the address of some structure > which can be freed at any time.
Sorry, I expressed myself quite badly. What I wanted to know is whether you are worried with the task been freed between saving its pointer and getting a ref on it (which is trivial to fix) or you are thinking of something deeper.
Thanks,
Sébastien. - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
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