On Mon, 2023-03-06 at 11:59 +0100, Claudio Imbrenda wrote:
> On Wed, 1 Mar 2023 14:26:38 +0100
> Nina Schoetterl-Glausch <nsg@xxxxxxxxxxxxx> wrote:
>
> > The operand of LOAD RELATIVE LONG must be word aligned, otherwise a
> > specification exception occurs. Test that this exception occurs.
>
> you're only testing halfword misalignment; would it make sense to test
> all possible misalignments? (it's only 3 of them after all)
No, that's not possible, the address calculation is:
insn_addr + immediate * 2
So for LRL there is only one possible misalignment.
For LGRL there are multiple, tho.
>
> >
> > Signed-off-by: Nina Schoetterl-Glausch <nsg@xxxxxxxxxxxxx>
> > ---
> >
> >
> > Noticed while writing another test that TCG fails this requirement,
> > so thought it best do document this in the form of a test.
> >
> >
> > s390x/spec_ex.c | 21 +++++++++++++++++++--
> > 1 file changed, 19 insertions(+), 2 deletions(-)
> >
> > diff --git a/s390x/spec_ex.c b/s390x/spec_ex.c
> > index 42ecaed3..42e86070 100644
> > --- a/s390x/spec_ex.c
> > +++ b/s390x/spec_ex.c
> > @@ -136,7 +136,7 @@ static int short_psw_bit_12_is_0(void)
> > return 0;
> > }
> >
> > -static int bad_alignment(void)
> > +static int bad_alignment_lqp(void)
> > {
> > uint32_t words[5] __attribute__((aligned(16)));
> > uint32_t (*bad_aligned)[4] = (uint32_t (*)[4])&words[1];
> > @@ -149,6 +149,22 @@ static int bad_alignment(void)
> > return 0;
> > }
> >
> > +static int bad_alignment_lrl(void)
> > +{
> > + uint64_t r;
> > +
> > + asm volatile ( ".pushsection .rodata\n"
>
> why not declare this as a local array?
I cannot put it on the stack, since I need a relative offset.
I guess I could use a global symbol, but that also makes the
test less self-contained.
>
> uint8_t stuff[8] __attribute__((aligned(8)));
>
> > + " .balign 4\n"
> > + " . = . + 2\n"
> > + "0: .fill 4\n"
> > + " .popsection\n"
> > +
> > + " lrl %0,0b\n"
> > + : "=d" (r)
>
> and here pass stuff + 1 or something like that?
>
> less asm = more readable
>
> > + );
> > + return 0;
> > +}
> > +
> > static int not_even(void)
> > {
> > uint64_t quad[2] __attribute__((aligned(16))) = {0};
> > @@ -176,7 +192,8 @@ struct spec_ex_trigger {
> > 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 },
> > - { "bad_alignment", &bad_alignment, true, NULL },
> > + { "bad_alignment_lqp", &bad_alignment_lqp, true, NULL },
> > + { "bad_alignment_lrl", &bad_alignment_lrl, true, NULL },
> > { "not_even", ¬_even, true, NULL },
> > { NULL, NULL, false, NULL },
> > };
> >
> > base-commit: e3c5c3ef2524c58023073c0fadde2e8ae3c04ec6
>
