Re: [Qemu-devel] [PATCH v2 09/27] linux-user/sh4: Clean env->flags on signal boundaries

[Aurelien Jarno]

On 2017-07-15 16:33, Richard Henderson wrote:
> On 07/15/2017 12:59 PM, Aurelien Jarno wrote:
> > On 2017-07-06 16:20, Richard Henderson wrote:
> > > If a signal is delivered during the execution of a delay slot,
> > > or a gUSA region, clear those bits from the environment so that
> > > the signal handler does not start in that same state.
> > 
> > How are signals delivered in linux-user? At least in system mode we
> > forbid interrupts in the delay slot (see commit 5c6f3eb7db), as the
> > manual clearly declare them as indivisible. Maybe the same should be
> > done for linux-user?
> 
> Signals get queued, and delivered eventually.  I don't believe that we do
> anything to check that "signals can't be delivered yet" like we do in system
> mode.

Ok. I think it might be a good idea to implement that. I am not always
sure that running the signal handler between an instruction and the
corresponding delay slot will lead to correct behaviour.

> > > +    regs->flags &= ~(DELAY_SLOT_MASK | GUSA_MASK);
> > >   }
> > >   static void setup_frame(int sig, struct target_sigaction *ka,
> > 
> > Why not using TB_FLAG_ENVFLAGS_MASK introduced earlier in this patch
> > series?
> 
> I really want to clear these two sets.  I didn't want to assume that
> ENVFLAGS_MASK would never contain anything else.
> 

Fair enough. Therefore:

Reviewed-by: Aurelien Jarno <address@hidden>

-- 
Aurelien Jarno                          GPG: 4096R/1DDD8C9B
address@hidden                 http://www.aurel32.net