On Tue, 11 Jan 2022 17:39:00 +0100
Janis Schoetterl-Glausch <scgl@xxxxxxxxxxxxx> wrote:
> Generate specification exceptions and check that they occur.
>
> Signed-off-by: Janis Schoetterl-Glausch <scgl@xxxxxxxxxxxxx>
> ---
> s390x/Makefile | 1 +
> s390x/spec_ex.c | 154 ++++++++++++++++++++++++++++++++++++++++++++
> s390x/unittests.cfg | 3 +
> 3 files changed, 158 insertions(+)
> create mode 100644 s390x/spec_ex.c
>
> diff --git a/s390x/Makefile b/s390x/Makefile
> index 1e567c1..5635c08 100644
> --- a/s390x/Makefile
> +++ b/s390x/Makefile
> @@ -25,6 +25,7 @@ tests += $(TEST_DIR)/uv-host.elf
> tests += $(TEST_DIR)/edat.elf
> tests += $(TEST_DIR)/mvpg-sie.elf
> tests += $(TEST_DIR)/spec_ex-sie.elf
> +tests += $(TEST_DIR)/spec_ex.elf
> tests += $(TEST_DIR)/firq.elf
>
> tests_binary = $(patsubst %.elf,%.bin,$(tests))
> diff --git a/s390x/spec_ex.c b/s390x/spec_ex.c
> new file mode 100644
> index 0000000..a9f9f31
> --- /dev/null
> +++ b/s390x/spec_ex.c
> @@ -0,0 +1,154 @@
> +// SPDX-License-Identifier: GPL-2.0-only
> +/*
> + * Copyright IBM Corp. 2021
> + *
> + * Specification exception test.
> + * Tests that specification exceptions occur when expected.
> + *
> + * Can be extended by adding triggers to spec_ex_triggers, see comments below.
> + */
> +#include <stdlib.h>
> +#include <libcflat.h>
> +#include <asm/interrupt.h>
> +
> +static struct lowcore *lc = (struct lowcore *) 0;
> +
> +static bool invalid_psw_expected;
> +static struct psw expected_psw;
> +static struct psw invalid_psw;
> +static struct psw fixup_psw;
> +
> +/* The standard program exception handler cannot deal with invalid old PSWs,
> + * especially not invalid instruction addresses, as in that case one cannot
> + * find the instruction following the faulting one from the old PSW.
> + * The PSW to return to is set by load_psw.
> + */
> +static void fixup_invalid_psw(void)
> +{
> + // signal occurrence of invalid psw fixup
> + invalid_psw_expected = false;
> + invalid_psw = lc->pgm_old_psw;
> + lc->pgm_old_psw = fixup_psw;
> +}
> +
> +/* Load possibly invalid psw, but setup fixup_psw before,
> + * so that *fixup_invalid_psw() can bring us back onto the right track.
is the * just a typo?
> + * Also acts as compiler barrier, -> none required in expect/check_invalid_psw
> + */
> +static void load_psw(struct psw psw)
> +{
> + uint64_t scratch;
> +
> + fixup_psw.mask = extract_psw_mask();
> + asm volatile ( "larl %[scratch],nop%=\n"
> + " stg %[scratch],%[addr]\n"
> + " lpswe %[psw]\n"
> + "nop%=: nop\n"
> + : [scratch] "=&r"(scratch),
> + [addr] "=&T"(fixup_psw.addr)
> + : [psw] "Q"(psw)
> + : "cc", "memory"
> + );
> +}
> +
> +static void expect_invalid_psw(struct psw psw)
> +{
> + expected_psw = psw;
> + invalid_psw_expected = true;
> +}
> +
> +static int check_invalid_psw(void)
> +{
> + // toggled to signal occurrence of invalid psw fixup
please use /* */ style of comments also for single line comments
> + if (!invalid_psw_expected) {
> + if (expected_psw.mask == invalid_psw.mask &&
> + expected_psw.addr == invalid_psw.addr)
> + return 0;
> + report_fail("Wrong invalid PSW");
> + } else {
> + report_fail("Expected exception due to invalid PSW");
> + }
> + return 1;
> +}
> +
> +static int psw_bit_12_is_1(void)
> +{
> + struct psw invalid = { .mask = 0x0008000000000000, .addr = 0x00000000deadbeee};
> +
> + expect_invalid_psw(invalid);
> + load_psw(expected_psw);
> + return check_invalid_psw();
> +}
> +
> +static int bad_alignment(void)
> +{
> + uint32_t words[5] __attribute__((aligned(16)));
> + uint32_t (*bad_aligned)[4] = (uint32_t (*)[4])&words[1];
> +
> + asm volatile ("lpq %%r6,%[bad]"
> + : : [bad] "T"(*bad_aligned)
> + : "%r6", "%r7"
> + );
> + return 0;
> +}
> +
> +static int not_even(void)
> +{
> + uint64_t quad[2] __attribute__((aligned(16))) = {0};
> +
> + asm volatile (".insn rxy,0xe3000000008f,%%r7,%[quad]" //lpq %%r7,%[quad]
> + : : [quad] "T"(quad)
> + : "%r7", "%r8"
> + );
> + return 0;
> +}
> +
> +/*
> + * Harness for specification exception testing.
> + * func only triggers exception, reporting is taken care of automatically.
> + */
> +struct spec_ex_trigger {
> + const char *name;
> + int (*func)(void);
> + void (*fixup)(void);
> +};
> +
> +/* List of all tests to execute */
> +static const struct spec_ex_trigger spec_ex_triggers[] = {
> + { "psw_bit_12_is_1", &psw_bit_12_is_1, &fixup_invalid_psw },
> + { "bad_alignment", &bad_alignment, NULL },
> + { "not_even", ¬_even, NULL },
> + { NULL, NULL, NULL },
> +};
> +
> +static void test_spec_ex(const struct spec_ex_trigger *trigger)
> +{
> + uint16_t expected_pgm = PGM_INT_CODE_SPECIFICATION;
> + uint16_t pgm;
> + int rc;
> +
> + expect_pgm_int();
> + register_pgm_cleanup_func(trigger->fixup);
> + rc = trigger->func();
> + register_pgm_cleanup_func(NULL);
> + if (rc)
> + return;
why do you exit early in case of failure? (moreover, your are not even
reporting the failure)
> + pgm = clear_pgm_int();
> + report(pgm == expected_pgm, "Program interrupt: expected(%d) == received(%d)",
> + expected_pgm, pgm);
> +}
> +
> +int main(int argc, char **argv)
> +{
> + unsigned int i;
> +
> + report_prefix_push("specification exception");
> + for (i = 0; spec_ex_triggers[i].name; i++) {
> + report_prefix_push(spec_ex_triggers[i].name);
> + test_spec_ex(&spec_ex_triggers[i]);
> + report_prefix_pop();
> + }
> + report_prefix_pop();
> +
> + return report_summary();
> +}
> diff --git a/s390x/unittests.cfg b/s390x/unittests.cfg
> index 054560c..26510cf 100644
> --- a/s390x/unittests.cfg
> +++ b/s390x/unittests.cfg
> @@ -113,6 +113,9 @@ file = mvpg-sie.elf
> [spec_ex-sie]
> file = spec_ex-sie.elf
>
> +[spec_ex]
> +file = spec_ex.elf
> +
> [firq-linear-cpu-ids]
> file = firq.elf
> timeout = 20
