[PATCH v4 3/4] y2038: Add tests for the sc_cobalt_sem_timedwait64 syscall

[Jan Kiszka]

On 07.05.21 14:49, Florian Bezdeka wrote:
> Introducing a new smokey plugin that can be extended for all kind of
> y2038 tests. For now we are testing the new sc_cobalt_sem_timedwait64
> syscall without using any libc wrappers provided by libcobalt.
> 
> Signed-off-by: Florian Bezdeka <florian.bezdeka at siemens.com>
> ---
>  configure.ac                           |   1 +
>  testsuite/smokey/Makefile.am           |   6 +-
>  testsuite/smokey/y2038/Makefile.am     |  10 ++
>  testsuite/smokey/y2038/syscall-tests.c | 177 +++++++++++++++++++++++++
>  4 files changed, 192 insertions(+), 2 deletions(-)
>  create mode 100644 testsuite/smokey/y2038/Makefile.am
>  create mode 100644 testsuite/smokey/y2038/syscall-tests.c
> 
> diff --git a/configure.ac b/configure.ac
> index abe538dbd..bd5fd5ba9 100644
> --- a/configure.ac
> +++ b/configure.ac
> @@ -990,6 +990,7 @@ AC_CONFIG_FILES([ \
>  	testsuite/smokey/net_common/Makefile \
>  	testsuite/smokey/cpu-affinity/Makefile \
>  	testsuite/smokey/gdb/Makefile \
> +	testsuite/smokey/y2038/Makefile \
>  	testsuite/clocktest/Makefile \
>  	testsuite/xeno-test/Makefile \
>  	utils/Makefile \
> diff --git a/testsuite/smokey/Makefile.am b/testsuite. Eventually, we /smokey/Makefile.am
> index 02613c7dc..56c873026 100644
> --- a/testsuite/smokey/Makefile.am
> +++ b/testsuite/smokey/Makefile.am
> @@ -38,7 +38,8 @@ COBALT_SUBDIRS = 	\
>  	timerfd		\
>  	tsc		\
>  	vdso-access 	\
> -	xddp
> +	xddp		\
> +	y2038
>  
>  MERCURY_SUBDIRS =	\
>  	memory-heapmem	\
> @@ -76,7 +77,8 @@ DIST_SUBDIRS = 		\
>  	timerfd		\
>  	tsc		\
>  	vdso-access 	\
> -	xddp
> +	xddp		\
> +	y2038
>  
>  if XENO_COBALT
>  if CONFIG_XENO_LIBS_DLOPEN
> diff --git a/testsuite/smokey/y2038/Makefile.am b/testsuite/smokey/y2038/Makefile.am
> new file mode 100644
> index 000000000..4bf629e87
> --- /dev/null
> +++ b/testsuite/smokey/y2038/Makefile.am
> @@ -0,0 +1,10 @@
> +
> +noinst_LIBRARIES = liby2038.a
> +
> +liby2038_a_SOURCES = syscall-tests.c
> +
> +liby2038_a_CPPFLAGS = 	\
> +	@XENO_USER_CFLAGS@	\
> +	-I$(top_srcdir)		\
> +	-I$(top_srcdir)/include \
> +	-I$(top_srcdir)/lib/cobalt/arch/@XENO_TARGET_ARCH@/include

Is that really needed? How do libs get access to those headers?

> diff --git a/testsuite/smokey/y2038/syscall-tests.c b/testsuite/smokey/y2038/syscall-tests.c
> new file mode 100644
> index 000000000..9d5b93ef9
> --- /dev/null
> +++ b/testsuite/smokey/y2038/syscall-tests.c
> @@ -0,0 +1,177 @@
> +/*
> + * y2038 tests
> + *
> + * Copyright (c) Siemens AG 2021
> + *
> + * Authors:
> + *  Florian Bezdeka <florian.bezdeka at siemens.com>
> + *
> + * Released under the terms of GPLv2.
> + */
> +#include <asm/xenomai/syscall.h>
> +#include <cobalt/uapi/syscall.h>
> +#include <smokey/smokey.h>
> +#include <semaphore.h>
> +#include <unistd.h>
> +#include <stdint.h>
> +#include <stdbool.h>
> +#include <errno.h>
> +
> +smokey_test_plugin(y2038, SMOKEY_NOARGS, "Validate correct y2038 support");
> +
> +/*
> + * libc independent data type representing a time64_t based struct timespec
> + */
> +struct xn_timespec64 {
> +	int64_t tv_sec;
> +	int64_t tv_nsec;
> +};
> +
> +#define NSEC_PER_SEC 1000000000
> +
> +static void ts_normalise(struct xn_timespec64 *ts)
> +{
> +	while (ts->tv_nsec >= NSEC_PER_SEC) {
> +		ts->tv_nsec += 1;
> +		ts->tv_nsec -= NSEC_PER_SEC;
> +	}
> +
> +	while (ts->tv_nsec <= -NSEC_PER_SEC) {
> +		ts->tv_sec -= 1;
> +		ts->tv_nsec += NSEC_PER_SEC;
> +	}
> +
> +	if (ts->tv_nsec < 0) {
> +		/*
> +		 * Negative nanoseconds isn't valid according to POSIX.
> +		 * Decrement tv_sec and roll tv_nsec over.
> +		 */
> +		ts->tv_sec -= 1;
> +		ts->tv_nsec = (NSEC_PER_SEC + ts->tv_nsec);
> +	}
> +}
> +
> +static inline void ts_add_ns(struct xn_timespec64 *ts, int ns)
> +{
> +	ts->tv_nsec += ns;
> +	ts_normalise(ts);
> +}
> +
> +/**
> + * Compare two struct timespec instances
> + *
> + * @param a
> + * @param b
> + * @return True if a < b, false otherwise
> + */
> +static inline bool ts_less(const struct xn_timespec64 *a,
> +			   const struct xn_timespec64 *b)
> +{
> +	if (a->tv_sec < b->tv_sec)
> +		return true;
> +
> +	if (a->tv_sec > b->tv_sec)
> +		return false;
> +
> +	/* a->tv_sec == b->tv_sec */
> +
> +	if (a->tv_nsec < b->tv_nsec)
> +		return true;
> +
> +	return false;
> +}
> +
> +static int test_sc_cobalt_sem_timedwait64(void)
> +{
> +	int ret;
> +	sem_t sem;
> +	int sc_nr = sc_cobalt_sem_timedwait64;

Why a variable? Do shorting the statements?

How about wrapping the calls into helper functions (one per new syscall)?

> +	struct xn_timespec64 ts64, ts_wu;
> +	struct timespec ts_nat;
> +
> +	sem_init(&sem, 0, 0);
> +
> +	/* Make sure we don't crash because of NULL pointers */
> +	ret = XENOMAI_SYSCALL2(sc_nr, NULL, NULL);
> +	if (ret == -ENOSYS) {
> +		smokey_note("sem_timedwait64: skipped. (no kernel support)");
> +		return 0; // Not implemented, nothing to test, success
> +	}
> +	if (!smokey_assert(ret == -EINVAL))
> +		return ret;
> +
> +	/* Timeout is never read by the kernel, so NULL should be OK */
> +	sem_post(&sem);
> +	ret = XENOMAI_SYSCALL2(sc_nr, &sem, NULL);
> +	if (!smokey_assert(!ret))
> +		return ret;
> +
> +	/*
> +	 * The semaphore is already exhausted, so calling again will validate
> +	 * the provided timeout now. Providing NULL has to deliver EFAULT
> +	 */
> +	ret = XENOMAI_SYSCALL2(sc_nr, &sem, NULL);
> +	if (!smokey_assert(ret == -EFAULT))
> +		return ret;
> +
> +	/*
> +	 * The semaphore is already exhausted, so calling again will validate
> +	 * the provided timeout now. Providing an invalid adress has to deliver
> +	 * EFAULT
> +	 */
> +	ret = XENOMAI_SYSCALL2(sc_nr, &sem, (void *)0xdeadbeefUL);
> +	if (!smokey_assert(ret == -EFAULT))
> +		return ret;
> +
> +	/*
> +	 * The semaphore is still exhausted, calling again will validate the
> +	 * timeout, providing an invalid timeout has to deliver EINVAL
> +	 */
> +	ts64.tv_sec = -1;
> +	ret = XENOMAI_SYSCALL2(sc_nr, &sem, &ts64);
> +	if (!smokey_assert(ret == -EINVAL))
> +		return ret;
> +
> +	/*
> +	 * Providing a valid timeout, waiting for it to time out and check
> +	 * that we didn't come back to early.
> +	 */
> +	ret = clock_gettime(CLOCK_MONOTONIC, &ts_nat);
> +	if (ret)
> +		return ret;
> +
> +	ts64.tv_sec = ts_nat.tv_sec;
> +	ts64.tv_nsec = ts_nat.tv_nsec;
> +	ts_add_ns(&ts64, 500000);
> +
> +	ret = XENOMAI_SYSCALL2(sc_nr, &sem, &ts64);
> +	if (!smokey_assert(ret == -ETIMEDOUT))
> +		return ret;
> +
> +	ret = clock_gettime(CLOCK_MONOTONIC, &ts_nat);
> +	if (ret)
> +		return ret;
> +
> +	ts_wu.tv_sec = ts_nat.tv_sec;
> +	ts_wu.tv_nsec = ts_nat.tv_nsec;
> +
> +	if (ts_less(&ts_wu, &ts64))
> +		smokey_warning("sem_timedwait64 returned to early!\n"
> +			       "Expected wakeup at: %lld sec %lld nsec\n"
> +			       "Back at           : %lld sec %lld nsec\n",
> +			       ts64.tv_sec, ts64.tv_nsec, ts_wu.tv_sec,
> +			       ts_wu.tv_nsec);
> +
> +	return 0;
> +}
> +
> +static int run_y2038(struct smokey_test *t, int argc, char *const argv[])
> +{
> +	int ret;
> +
> +	ret = test_sc_cobalt_sem_timedwait64();
> +	if (ret)
> +		return ret;
> +
> +	return 0;
> +}
> 

Jan

-- 
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