On Tue, 2023-03-14 at 18:12 +0100, Claudio Imbrenda wrote:
> On Tue, 14 Mar 2023 17:41:24 +0100
> Nina Schoetterl-Glausch <nsg@xxxxxxxxxxxxx> wrote:
>
> > On Tue, 2023-03-14 at 16:25 +0100, Claudio Imbrenda wrote:
> > > On Tue, 21 Feb 2023 18:48:22 +0100
> > > Nina Schoetterl-Glausch <nsg@xxxxxxxxxxxxx> wrote:
> > >
> > > > The EXECUTE instruction executes the instruction at the given target
> > > > address. This address must be halfword aligned, otherwise a
> > > > specification exception occurs.
> > > > Add a test for this.
> > > >
> > > > Signed-off-by: Nina Schoetterl-Glausch <nsg@xxxxxxxxxxxxx>
> > > > ---
> > > > s390x/spec_ex.c | 25 +++++++++++++++++++++++++
> > > > 1 file changed, 25 insertions(+)
> > > >
> > > > diff --git a/s390x/spec_ex.c b/s390x/spec_ex.c
> > > > index a26c56aa..dd097f9b 100644
> > > > --- a/s390x/spec_ex.c
> > > > +++ b/s390x/spec_ex.c
> > > > @@ -177,6 +177,30 @@ static int short_psw_bit_12_is_0(void)
> > > > return 0;
> > > > }
> > > >
> > > > +static int odd_ex_target(void)
> > > > +{
> > > > + uint64_t pre_target_addr;
> > > > + int to = 0, from = 0x0dd;
> > > > +
> > > > + asm volatile ( ".pushsection .rodata\n"
> > >
> > > and this should go in a .text.something subsection, as we discussed
> > > offline
> >
> > Yes.
> > >
> > > > + "pre_odd_ex_target:\n"
> > >
> > > shouldn't the label be after the align?
> >
> > No, larl needs an aligned address, and the ex below adds 1.
> > That's why it has the pre_ prefix, it's not the ex target itself.
>
> I understand that, but
> > >
> > > > + " .balign 2\n"
>
> doesn't the address get aligned here?
> so the label here would be aligned to 2
Uh, yeah, sorry.
>
> > >
> > > (i.e. here)
> > >
> > > > + " . = . + 1\n"
>
> and here it gets the +1?
>
> > > > + " lr %[to],%[from]\n"
> > > > + " .popsection\n"
> > > > +
> > > > + " larl %[pre_target_addr],pre_odd_ex_target\n"
> > > > + " ex 0,1(%[pre_target_addr])\n"
> > > > + : [pre_target_addr] "=&a" (pre_target_addr),
> > > > + [to] "+d" (to)
> > > > + : [from] "d" (from)
> > > > + );
> > > > +
> > > > + assert((pre_target_addr + 1) & 1);
> > > > + report(to != from, "did not perform ex with odd target");
> > > > + return 0;
> > > > +}
> > > > +
> > > > static int bad_alignment(void)
> > > > {
> > > > uint32_t words[5] __attribute__((aligned(16)));
> > > > @@ -218,6 +242,7 @@ static const struct spec_ex_trigger spec_ex_triggers[] = {
> > > > { "psw_bit_12_is_1", &psw_bit_12_is_1, false, &fixup_invalid_psw },
> > > > { "short_psw_bit_12_is_0", &short_psw_bit_12_is_0, false, &fixup_invalid_psw },
> > > > { "psw_odd_address", &psw_odd_address, false, &fixup_invalid_psw },
> > > > + { "odd_ex_target", &odd_ex_target, true, NULL },
> > > > { "bad_alignment", &bad_alignment, true, NULL },
> > > > { "not_even", ¬_even, true, NULL },
> > > > { NULL, NULL, false, NULL },
> > >
> >
>
