From: Nina Schoetterl-Glausch <nsg@xxxxxxxxxxxxx> Instructions on s390 must be halfword aligned. Introducing an odd instruction address into the PSW leads to a specification exception when attempting to execute the instruction at the odd address. Add a test for this. Acked-by: Janosch Frank <frankja@xxxxxxxxxxxxx> Reviewed-by: Claudio Imbrenda <imbrenda@xxxxxxxxxxxxx> Signed-off-by: Nina Schoetterl-Glausch <nsg@xxxxxxxxxxxxx> Reviewed-by: Nico Boehr <nrb@xxxxxxxxxxxxx> Tested-by: Nico Boehr <nrb@xxxxxxxxxxxxx> Link: https://lore.kernel.org/r/20230404085454.2709061-3-nsg@xxxxxxxxxxxxx Signed-off-by: Nico Boehr <nrb@xxxxxxxxxxxxx> --- s390x/spec_ex.c | 50 ++++++++++++++++++++++++++++++++++++++++++++++++- 1 file changed, 49 insertions(+), 1 deletion(-) diff --git a/s390x/spec_ex.c b/s390x/spec_ex.c index 2adc599..494d94c 100644 --- a/s390x/spec_ex.c +++ b/s390x/spec_ex.c @@ -88,12 +88,23 @@ static void expect_invalid_psw(struct psw psw) invalid_psw_expected = true; } +static void clear_invalid_psw(void) +{ + expected_psw = PSW(0, 0); + invalid_psw_expected = false; +} + static int check_invalid_psw(void) { /* Since the fixup sets this to false we check for false here. */ if (!invalid_psw_expected) { + /* + * Early exception recognition: pgm_int_id == 0. + * Late exception recognition: psw address has been + * incremented by pgm_int_id (unpredictable value) + */ if (expected_psw.mask == invalid_psw.mask && - expected_psw.addr == invalid_psw.addr) + expected_psw.addr == invalid_psw.addr - lowcore.pgm_int_id) return 0; report_fail("Wrong invalid PSW"); } else { @@ -112,6 +123,42 @@ static int psw_bit_12_is_1(void) return check_invalid_psw(); } +extern char misaligned_code_pre[]; +asm ( ".balign 2\n" +"misaligned_code_pre:\n" +" . = . + 1\n" +" larl %r0,0\n" +" br %r1\n" +); + +static int psw_odd_address(void) +{ + struct psw odd = PSW_WITH_CUR_MASK(((uint64_t)&misaligned_code_pre) + 1); + uint64_t executed_addr; + + expect_invalid_psw(odd); + fixup_psw.mask = extract_psw_mask(); + asm volatile ( "xgr %%r0,%%r0\n" + " larl %%r1,0f\n" + " stg %%r1,%[fixup_addr]\n" + " lpswe %[odd_psw]\n" + "0: lr %[executed_addr],%%r0\n" + : [fixup_addr] "=&T" (fixup_psw.addr), + [executed_addr] "=d" (executed_addr) + : [odd_psw] "Q" (odd) + : "cc", "%r0", "%r1", "memory" /* Compiler barrier like in load_psw */ + ); + + if (!executed_addr) { + return check_invalid_psw(); + } else { + assert(executed_addr == odd.addr); + clear_invalid_psw(); + report_fail("did not execute unaligned instructions"); + return 1; + } +} + /* A short PSW needs to have bit 12 set to be valid. */ static int short_psw_bit_12_is_0(void) { @@ -170,6 +217,7 @@ 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 }, + { "psw_odd_address", &psw_odd_address, false, &fixup_invalid_psw }, { "bad_alignment", &bad_alignment, true, NULL }, { "not_even", ¬_even, true, NULL }, { NULL, NULL, false, NULL }, -- 2.39.2
