selftests: rtc: rtctest: Do not open-code TEST_HARNESS_MAIN

Argument processing is specific to the test harness code. Any optional
information needs to be passed via environment variables. Move alternate
path to the RTC_DEV environment variable. Also do not open-code
TEST_HARNESS_MAIN because its definition may change.

Additionally, setup checking can be done in the FIXTURE_SETUP(). With
this adjustment, also improve the error reporting when the device cannot
be opened.

Signed-off-by: Kees Cook <keescook@chromium.org>
---
Cc: Alexandre Belloni <alexandre.belloni@bootlin.com>
Cc: Shuah Khan <shuah@kernel.org>
Cc: Masahiro Yamada <masahiroy@kernel.org>
Cc: linux-rtc@vger.kernel.org
Cc: linux-kselftest@vger.kernel.org
---
 tools/testing/selftests/rtc/Makefile  |  2 +-
 tools/testing/selftests/rtc/rtctest.c | 66 +++++----------------------
 2 files changed, 13 insertions(+), 55 deletions(-)

On 17/05/2024 17:16:58-0700, Kees Cook wrote:
> Argument processing is specific to the test harness code. Any optional
> information needs to be passed via environment variables. Move alternate
> path to the RTC_DEV environment variable. Also do not open-code
> TEST_HARNESS_MAIN because its definition may change.

Th main issue doing that is that this breaks the main use case of
rtctest as /dev/rtc1 is usually the main target for those tests. Having
the RTC_DEV environment variable only documented n this commit message
is definitively not enough, I'm going to have to handle zillion of
complaints that this is not working anymore.

> 
> Additionally, setup checking can be done in the FIXTURE_SETUP(). With
> this adjustment, also improve the error reporting when the device cannot
> be opened.
> 
> Signed-off-by: Kees Cook <keescook@chromium.org>
> ---
> Cc: Alexandre Belloni <alexandre.belloni@bootlin.com>
> Cc: Shuah Khan <shuah@kernel.org>
> Cc: Masahiro Yamada <masahiroy@kernel.org>
> Cc: linux-rtc@vger.kernel.org
> Cc: linux-kselftest@vger.kernel.org
> ---
>  tools/testing/selftests/rtc/Makefile  |  2 +-
>  tools/testing/selftests/rtc/rtctest.c | 66 +++++----------------------
>  2 files changed, 13 insertions(+), 55 deletions(-)
> 
> diff --git a/tools/testing/selftests/rtc/Makefile b/tools/testing/selftests/rtc/Makefile
> index 55198ecc04db..654f9d58da3c 100644
> --- a/tools/testing/selftests/rtc/Makefile
> +++ b/tools/testing/selftests/rtc/Makefile
> @@ -1,5 +1,5 @@
>  # SPDX-License-Identifier: GPL-2.0
> -CFLAGS += -O3 -Wl,-no-as-needed -Wall
> +CFLAGS += -O3 -Wl,-no-as-needed -Wall $(KHDR_INCLUDES)
>  LDLIBS += -lrt -lpthread -lm
>  
>  TEST_GEN_PROGS = rtctest
> diff --git a/tools/testing/selftests/rtc/rtctest.c b/tools/testing/selftests/rtc/rtctest.c
> index 63ce02d1d5cc..41cfefcc20e1 100644
> --- a/tools/testing/selftests/rtc/rtctest.c
> +++ b/tools/testing/selftests/rtc/rtctest.c
> @@ -30,7 +30,18 @@ FIXTURE(rtc) {
>  };
>  
>  FIXTURE_SETUP(rtc) {
> +	char *alternate = getenv("RTC_DEV");
> +
> +	if (alternate)
> +		rtc_file = alternate;
> +
>  	self->fd = open(rtc_file, O_RDONLY);
> +
> +	if (self->fd == -1 && errno == ENOENT)
> +		SKIP(return, "Skipping test since %s does not exist", rtc_file);
> +	EXPECT_NE(-1, self->fd) {
> +		TH_LOG("%s: %s\n", rtc_file, strerror(errno));
> +	}
>  }
>  
>  FIXTURE_TEARDOWN(rtc) {
> @@ -41,10 +52,6 @@ TEST_F(rtc, date_read) {
>  	int rc;
>  	struct rtc_time rtc_tm;
>  
> -	if (self->fd == -1 && errno == ENOENT)
> -		SKIP(return, "Skipping test since %s does not exist", rtc_file);
> -	ASSERT_NE(-1, self->fd);
> -
>  	/* Read the RTC time/date */
>  	rc = ioctl(self->fd, RTC_RD_TIME, &rtc_tm);
>  	ASSERT_NE(-1, rc);
> @@ -88,10 +95,6 @@ TEST_F_TIMEOUT(rtc, date_read_loop, READ_LOOP_DURATION_SEC + 2) {
>  	struct rtc_time rtc_tm;
>  	time_t start_rtc_read, prev_rtc_read;
>  
> -	if (self->fd == -1 && errno == ENOENT)
> -		SKIP(return, "Skipping test since %s does not exist", rtc_file);
> -	ASSERT_NE(-1, self->fd);
> -
>  	TH_LOG("Continuously reading RTC time for %ds (with %dms breaks after every read).",
>  	       READ_LOOP_DURATION_SEC, READ_LOOP_SLEEP_MS);
>  
> @@ -126,10 +129,6 @@ TEST_F_TIMEOUT(rtc, uie_read, NUM_UIE + 2) {
>  	int i, rc, irq = 0;
>  	unsigned long data;
>  
> -	if (self->fd == -1 && errno == ENOENT)
> -		SKIP(return, "Skipping test since %s does not exist", rtc_file);
> -	ASSERT_NE(-1, self->fd);
> -
>  	/* Turn on update interrupts */
>  	rc = ioctl(self->fd, RTC_UIE_ON, 0);
>  	if (rc == -1) {
> @@ -155,10 +154,6 @@ TEST_F(rtc, uie_select) {
>  	int i, rc, irq = 0;
>  	unsigned long data;
>  
> -	if (self->fd == -1 && errno == ENOENT)
> -		SKIP(return, "Skipping test since %s does not exist", rtc_file);
> -	ASSERT_NE(-1, self->fd);
> -
>  	/* Turn on update interrupts */
>  	rc = ioctl(self->fd, RTC_UIE_ON, 0);
>  	if (rc == -1) {
> @@ -198,10 +193,6 @@ TEST_F(rtc, alarm_alm_set) {
>  	time_t secs, new;
>  	int rc;
>  
> -	if (self->fd == -1 && errno == ENOENT)
> -		SKIP(return, "Skipping test since %s does not exist", rtc_file);
> -	ASSERT_NE(-1, self->fd);
> -
>  	rc = ioctl(self->fd, RTC_RD_TIME, &tm);
>  	ASSERT_NE(-1, rc);
>  
> @@ -256,10 +247,6 @@ TEST_F(rtc, alarm_wkalm_set) {
>  	time_t secs, new;
>  	int rc;
>  
> -	if (self->fd == -1 && errno == ENOENT)
> -		SKIP(return, "Skipping test since %s does not exist", rtc_file);
> -	ASSERT_NE(-1, self->fd);
> -
>  	rc = ioctl(self->fd, RTC_RD_TIME, &alarm.time);
>  	ASSERT_NE(-1, rc);
>  
> @@ -308,10 +295,6 @@ TEST_F_TIMEOUT(rtc, alarm_alm_set_minute, 65) {
>  	time_t secs, new;
>  	int rc;
>  
> -	if (self->fd == -1 && errno == ENOENT)
> -		SKIP(return, "Skipping test since %s does not exist", rtc_file);
> -	ASSERT_NE(-1, self->fd);
> -
>  	rc = ioctl(self->fd, RTC_RD_TIME, &tm);
>  	ASSERT_NE(-1, rc);
>  
> @@ -366,10 +349,6 @@ TEST_F_TIMEOUT(rtc, alarm_wkalm_set_minute, 65) {
>  	time_t secs, new;
>  	int rc;
>  
> -	if (self->fd == -1 && errno == ENOENT)
> -		SKIP(return, "Skipping test since %s does not exist", rtc_file);
> -	ASSERT_NE(-1, self->fd);
> -
>  	rc = ioctl(self->fd, RTC_RD_TIME, &alarm.time);
>  	ASSERT_NE(-1, rc);
>  
> @@ -410,25 +389,4 @@ TEST_F_TIMEOUT(rtc, alarm_wkalm_set_minute, 65) {
>  	ASSERT_EQ(new, secs);
>  }
>  
> -static void __attribute__((constructor))
> -__constructor_order_last(void)
> -{
> -	if (!__constructor_order)
> -		__constructor_order = _CONSTRUCTOR_ORDER_BACKWARD;
> -}
> -
> -int main(int argc, char **argv)
> -{
> -	switch (argc) {
> -	case 2:
> -		rtc_file = argv[1];
> -		/* FALLTHROUGH */
> -	case 1:
> -		break;
> -	default:
> -		fprintf(stderr, "usage: %s [rtcdev]\n", argv[0]);
> -		return 1;
> -	}
> -
> -	return test_harness_run(argc, argv);
> -}
> +TEST_HARNESS_MAIN
> -- 
> 2.34.1
>

On Sat, May 18, 2024 at 10:23:54PM +0200, Alexandre Belloni wrote:
> On 17/05/2024 17:16:58-0700, Kees Cook wrote:
> > Argument processing is specific to the test harness code. Any optional
> > information needs to be passed via environment variables. Move alternate
> > path to the RTC_DEV environment variable. Also do not open-code
> > TEST_HARNESS_MAIN because its definition may change.
> 
> Th main issue doing that is that this breaks the main use case of
> rtctest as /dev/rtc1 is usually the main target for those tests. Having
> the RTC_DEV environment variable only documented n this commit message
> is definitively not enough, I'm going to have to handle zillion of
> complaints that this is not working anymore.

Hm, maybe switch the default to /dev/rtc1? Maybe there's a better way to
integrate arguments into a test runner. Right now the core harness code
is doing the argument parsing...