Re: SIGFPE trapping on HPPA (was: Yorick FTBFS: DM needs access to HPPA machine)

["Carlos O'Donell" <carlos@systemhalted.org>]

On Mon, Dec 14, 2009 at 9:32 AM, Thibaut Paumard <mlotpot.news@free.fr> wrote:
> Under some circumstances (when and integer SIGFPE has been raised
> previously), I have been able to have my handler output a short message, but
> then it loops (this short message is repeated indefinitely). Calling
> feclearexcepts() before outputting this message did not help: when
> attempting a floating-point division by zero, either yorick dies or the
> handler loops. The first three lines of the handler on this test case are:
>  feclearexcept(FE_ALL_EXCEPT);
>  printf("in u_sigfpe\n");
>  fflush(stdout);
>
> The handler is setup using signal(2):
>  signal(SIGFPE, &u_sigfpe)
>
> HPPA is the only architecture so far which exhibits this behaviour.
>
> Does anyone has an idea of what I could do to fix this? Is there something
> specific in the way HPPA handles SIGFPE trapping? Why is it different
> between integer SIGFPE and floating SIGFPE?

Could you please provide a small test case and describe the expected behaviour?

I'll look at the test case and see if there is any corner cases
missing from the glibc floating point exception handling code.

Cheers,
Carlos.