On Mon, 4 Dec 2006 22:43:13 +0530 Bharata B Rao <[EMAIL PROTECTED]> wrote:
> On Wed, Nov 29, 2006 at 11:32:34AM +0100, Sébastien Dugué wrote:
> >
> > <snip>
> > +/***
> > + * good_sigevent - check and get target task from a sigevent.
> > + * @event: the sigevent to be checked
> > + *
> > + * This function must be called with tasklist_lock held for reading.
> > + */
> > +struct task_struct * good_sigevent(sigevent_t * event)
> > +{
> > + struct task_struct *rtn = current->group_leader;
> > +
> > + if ((event->sigev_notify & SIGEV_THREAD_ID ) &&
> > + (!(rtn = find_task_by_pid(event->sigev_notify_thread_id)) ||
> > + rtn->tgid != current->tgid ||
> > + (event->sigev_notify & ~SIGEV_THREAD_ID) != SIGEV_SIGNAL))
> > + return NULL;
> > +
> > + if (((event->sigev_notify & ~SIGEV_THREAD_ID) != SIGEV_NONE) &&
> > + ((event->sigev_signo <= 0) || (event->sigev_signo > SIGRTMAX)))
> > + return NULL;
> > +
> > + return rtn;
> > +}
>
> Here good_sigevent() doesn't take care of SIGEV_THREAD. From this comment
> from include/asm-generic/siginfo.h,
>
> "It seems likely that SIGEV_THREAD will have to be handled from
> userspace, libpthread transmuting it to SIGEV_SIGNAL, which the
> thread manager then catches and does the appropriate nonsense.
> However, everything is written out here so as to not get lost."
>
> it looks like SIGEV_THREAD should never come into kernel. But atleast
> libposix-aio does send SIGEV_THREAD all the way up to kernel.
That's right, I had to reflect that change into libposix-aio, i.e. transmuting
SIGEV_THREAD into SIGEV_SIGNAL.
Sébastien.
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