Re: [Qemu-devel] [PATCH] linux-user: avoid treading on gprof's SIGPROF signals

[Laurent Desnogues]

On Thu, May 2, 2019 at 6:17 PM Laurent Vivier <address@hidden> wrote:
>
> On 02/05/2019 16:58, Alex Bennée wrote:
> > The guest tends to get confused when it receives signals it doesn't
> > know about. Given the gprof magic has also set up it's own handler we
> > would do well to avoid stomping on it as well.
> >
> > Signed-off-by: Alex Bennée <address@hidden>
> > ---
> >  linux-user/signal.c | 5 +++++
> >  1 file changed, 5 insertions(+)
> >
> > diff --git a/linux-user/signal.c b/linux-user/signal.c
> > index e2c0b37173..44b2d3b35a 100644
> > --- a/linux-user/signal.c
> > +++ b/linux-user/signal.c
> > @@ -508,6 +508,11 @@ void signal_init(void)
> >      act.sa_flags = SA_SIGINFO;
> >      act.sa_sigaction = host_signal_handler;
> >      for(i = 1; i <= TARGET_NSIG; i++) {
> > +#ifdef TARGET_GPROF
> > +        if (i == SIGPROF) {
> > +            continue;
> > +        }
> > +#endif
> >          host_sig = target_to_host_signal(i);
> >          sigaction(host_sig, NULL, &oact);
> >          if (oact.sa_sigaction == (void *)SIG_IGN) {
> >
>
> Perhaps merge this with the previous one and send a v2: it will ease
> bisecting.

I agree it would be better, though it should be noted that the signal
issue has existed for at least 8 years (that's when I had to add a
specific patch in my private repository).

Thanks,

Laurent