Re: [PATCH v2 07/43] blackfin: Use set_current_blocked() andblock_sigmask()

From: Matt Fleming
Date: Sat Aug 20 2011 - 04:36:56 EST


On Sat, 2011-08-20 at 00:00 -0400, Mike Frysinger wrote:
> On Fri, Aug 19, 2011 at 12:46, Matt Fleming wrote:
> > --- a/arch/blackfin/kernel/signal.c
> > +++ b/arch/blackfin/kernel/signal.c
> > - if (ret == 0) {
> > - spin_lock_irq(&current->sighand->siglock);
> > - sigorsets(&current->blocked, &current->blocked,
> > - &ka->sa.sa_mask);
> > - if (!(ka->sa.sa_flags & SA_NODEFER))
> > - sigaddset(&current->blocked, sig);
> > - recalc_sigpending();
> > - spin_unlock_irq(&current->sighand->siglock);
> > - }
> > + if (ret == 0)
> > + block_sigmask(ka, sig);
>
> the Blackfin version holds siglock and calls recalc_sigpending() while
> block_sigmask() does neither. i'm guessing that is expected behavior
> now ?

Yah, set_current_blocked() inside of block_sigmask() still grabs siglock
and calls recalc_sigpending() for you. Reading current->blocked inside
of block_sigmask() is fine and the sigorsets() is OK because we're
modifying a stack variable, so only grabbing the lock inside of
set_current_blocked() is safe.

--
Matt Fleming, Intel Open Source Technology Center

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