[PATCH 0/3] kselftest: Extend vDSO tests

[PATCH 0/3] kselftest: Extend vDSO tests

[Vincenzo Frascino]

This series extends the kselftests for the vDSO library making sure: that
they compile correctly on non x86 platforms, that they can be cross
compiled and introducing new tests that verify the correctness of the
library.

The so extended vDSO kselftests have been verified on all the platforms
supported by the unified vDSO library [1].

The only new patch that this series introduces is the first one, patch 2 and
patch 3 have already been reviewed in past as part of other series [2] [3].

[1] https://lore.kernel.org/lkml/20190621095252.32307-1-vincenzo.frascino@arm.com
[2] https://lore.kernel.org/lkml/20190621095252.32307-26-vincenzo.frascino@arm.com
[3] https://lore.kernel.org/lkml/20190523112116.19233-4-vincenzo.frascino@arm.com

Cc: Shuah Khan <shuah@kernel.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Andy Lutomirski <luto@kernel.org>
Signed-off-by: Vincenzo Frascino <vincenzo.frascino@arm.com>

Vincenzo Frascino (3):
  kselftest: Enable vDSO test on non x86 platforms
  kselftest: Extend vDSO selftest
  kselftest: Extend vDSO selftest to clock_getres

 tools/testing/selftests/Makefile              |   1 +
 tools/testing/selftests/vDSO/Makefile         |   6 +-
 .../selftests/vDSO/vdso_clock_getres.c        | 124 +++++++++
 tools/testing/selftests/vDSO/vdso_config.h    |  90 +++++++
 tools/testing/selftests/vDSO/vdso_full_test.c | 244 ++++++++++++++++++
 5 files changed, 463 insertions(+), 2 deletions(-)
 create mode 100644 tools/testing/selftests/vDSO/vdso_clock_getres.c
 create mode 100644 tools/testing/selftests/vDSO/vdso_config.h
 create mode 100644 tools/testing/selftests/vDSO/vdso_full_test.c

-- 
2.25.2

[PATCH 1/3] kselftest: Enable vDSO test on non x86 platforms

[Vincenzo Frascino]

Currently the vDSO tests are built only on x86 platforms and cannot be
cross compiled.

Enable vDSO TARGET for all the platforms.

Future patches will extend the tests.

Cc: Shuah Khan <shuah@kernel.org>
Signed-off-by: Vincenzo Frascino <vincenzo.frascino@arm.com>
---
 tools/testing/selftests/Makefile      | 1 +
 tools/testing/selftests/vDSO/Makefile | 2 --
 2 files changed, 1 insertion(+), 2 deletions(-)

diff --git a/tools/testing/selftests/Makefile b/tools/testing/selftests/Makefile
index 6ec503912bea..20aa4c68b88c 100644
--- a/tools/testing/selftests/Makefile
+++ b/tools/testing/selftests/Makefile
@@ -60,6 +60,7 @@ endif
 TARGETS += tmpfs
 TARGETS += tpm2
 TARGETS += user
+TARGETS += vDSO
 TARGETS += vm
 TARGETS += x86
 TARGETS += zram
diff --git a/tools/testing/selftests/vDSO/Makefile b/tools/testing/selftests/vDSO/Makefile
index 9e03d61f52fd..2989e4d5a730 100644
--- a/tools/testing/selftests/vDSO/Makefile
+++ b/tools/testing/selftests/vDSO/Makefile
@@ -9,7 +9,6 @@ ifeq ($(ARCH),x86)
 TEST_GEN_PROGS += $(OUTPUT)/vdso_standalone_test_x86
 endif
 
-ifndef CROSS_COMPILE
 CFLAGS := -std=gnu99
 CFLAGS_vdso_standalone_test_x86 := -nostdlib -fno-asynchronous-unwind-tables -fno-stack-protector
 ifeq ($(CONFIG_X86_32),y)
@@ -23,4 +22,3 @@ $(OUTPUT)/vdso_standalone_test_x86: vdso_standalone_test_x86.c parse_vdso.c
 		vdso_standalone_test_x86.c parse_vdso.c \
 		-o $@
 
-endif
-- 
2.25.2

[PATCH 2/3] kselftest: Extend vDSO selftest

[Vincenzo Frascino]

The current version of the multiarch vDSO selftest verifies only
gettimeofday.

Extend the vDSO selftest to the other library functions:
 - time
 - clock_getres
 - clock_gettime

The extension has been used to verify the unified vdso library on the
supported architectures.

Cc: Shuah Khan <shuah@kernel.org>
Signed-off-by: Vincenzo Frascino <vincenzo.frascino@arm.com>
---
 tools/testing/selftests/vDSO/Makefile         |   2 +
 tools/testing/selftests/vDSO/vdso_config.h    |  90 +++++++
 tools/testing/selftests/vDSO/vdso_full_test.c | 244 ++++++++++++++++++
 3 files changed, 336 insertions(+)
 create mode 100644 tools/testing/selftests/vDSO/vdso_config.h
 create mode 100644 tools/testing/selftests/vDSO/vdso_full_test.c

diff --git a/tools/testing/selftests/vDSO/Makefile b/tools/testing/selftests/vDSO/Makefile
index 2989e4d5a730..46aab4eaccbd 100644
--- a/tools/testing/selftests/vDSO/Makefile
+++ b/tools/testing/selftests/vDSO/Makefile
@@ -5,6 +5,7 @@ uname_M := $(shell uname -m 2>/dev/null || echo not)
 ARCH ?= $(shell echo $(uname_M) | sed -e s/i.86/x86/ -e s/x86_64/x86/)
 
 TEST_GEN_PROGS := $(OUTPUT)/vdso_test
+TEST_GEN_PROGS += $(OUTPUT)/vdso_full_test
 ifeq ($(ARCH),x86)
 TEST_GEN_PROGS += $(OUTPUT)/vdso_standalone_test_x86
 endif
@@ -17,6 +18,7 @@ endif
 
 all: $(TEST_GEN_PROGS)
 $(OUTPUT)/vdso_test: parse_vdso.c vdso_test.c
+$(OUTPUT)/vdso_full_test: parse_vdso.c vdso_full_test.c
 $(OUTPUT)/vdso_standalone_test_x86: vdso_standalone_test_x86.c parse_vdso.c
 	$(CC) $(CFLAGS) $(CFLAGS_vdso_standalone_test_x86) \
 		vdso_standalone_test_x86.c parse_vdso.c \
diff --git a/tools/testing/selftests/vDSO/vdso_config.h b/tools/testing/selftests/vDSO/vdso_config.h
new file mode 100644
index 000000000000..eeb725df6045
--- /dev/null
+++ b/tools/testing/selftests/vDSO/vdso_config.h
@@ -0,0 +1,90 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * vdso_config.h: Configuration options for vDSO tests.
+ * Copyright (c) 2019 Arm Ltd.
+ */
+#ifndef __VDSO_CONFIG_H__
+#define __VDSO_CONFIG_H__
+
+/*
+ * Each architecture exports its vDSO implementation with different names
+ * and a different version from the others, so we need to handle it as a
+ * special case.
+ */
+#if defined(__arm__)
+#define VDSO_VERSION		0
+#define VDSO_NAMES		1
+#define VDSO_32BIT		1
+#elif defined(__aarch64__)
+#define VDSO_VERSION		3
+#define VDSO_NAMES		0
+#elif defined(__powerpc__)
+#define VDSO_VERSION		1
+#define VDSO_NAMES		0
+#define VDSO_32BIT		1
+#elif defined(__powerpc64__)
+#define VDSO_VERSION		1
+#define VDSO_NAMES		0
+#elif defined (__s390__)
+#define VDSO_VERSION		2
+#define VDSO_NAMES		0
+#define VDSO_32BIT		1
+#elif defined (__s390X__)
+#define VDSO_VERSION		2
+#define VDSO_NAMES		0
+#elif defined(__mips__)
+#define VDSO_VERSION		0
+#define VDSO_NAMES		1
+#define VDSO_32BIT		1
+#elif defined(__sparc__)
+#define VDSO_VERSION		0
+#define VDSO_NAMES		1
+#define VDSO_32BIT		1
+#elif defined(__i386__)
+#define VDSO_VERSION		0
+#define VDSO_NAMES		1
+#define VDSO_32BIT		1
+#elif defined(__x86_64__)
+#define VDSO_VERSION		0
+#define VDSO_NAMES		1
+#elif defined(__riscv__)
+#define VDSO_VERSION		5
+#define VDSO_NAMES		1
+#define VDSO_32BIT		1
+#else /* nds32 */
+#define VDSO_VERSION		4
+#define VDSO_NAMES		1
+#define VDSO_32BIT		1
+#endif
+
+static const char *versions[6] = {
+	"LINUX_2.6",
+	"LINUX_2.6.15",
+	"LINUX_2.6.29",
+	"LINUX_2.6.39",
+	"LINUX_4",
+	"LINUX_4.15",
+};
+
+static const char *names[2][5] = {
+	{
+		"__kernel_gettimeofday",
+		"__kernel_clock_gettime",
+		"__kernel_time",
+		"__kernel_clock_getres",
+#if defined(VDSO_32BIT)
+		"__kernel_clock_gettime64",
+#endif
+	},
+	{
+		"__vdso_gettimeofday",
+		"__vdso_clock_gettime",
+		"__vdso_time",
+		"__vdso_clock_getres",
+#if defined(VDSO_32BIT)
+		"__vdso_clock_gettime64",
+#endif
+	},
+};
+
+#endif /* __VDSO_CONFIG_H__ */
diff --git a/tools/testing/selftests/vDSO/vdso_full_test.c b/tools/testing/selftests/vDSO/vdso_full_test.c
new file mode 100644
index 000000000000..3d603f1394af
--- /dev/null
+++ b/tools/testing/selftests/vDSO/vdso_full_test.c
@@ -0,0 +1,244 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * vdso_full_test.c: Sample code to test all the timers.
+ * Copyright (c) 2019 Arm Ltd.
+ *
+ * Compile with:
+ * gcc -std=gnu99 vdso_full_test.c parse_vdso.c
+ *
+ */
+
+#include <stdint.h>
+#include <elf.h>
+#include <stdio.h>
+#include <time.h>
+#include <sys/auxv.h>
+#include <sys/time.h>
+#define _GNU_SOURCE
+#include <unistd.h>
+#include <sys/syscall.h>
+
+#include "../kselftest.h"
+#include "vdso_config.h"
+
+extern void *vdso_sym(const char *version, const char *name);
+extern void vdso_init_from_sysinfo_ehdr(uintptr_t base);
+extern void vdso_init_from_auxv(void *auxv);
+
+static const char *version;
+static const char **name;
+
+typedef long (*vdso_gettimeofday_t)(struct timeval *tv, struct timezone *tz);
+typedef long (*vdso_clock_gettime_t)(clockid_t clk_id, struct timespec *ts);
+typedef long (*vdso_clock_getres_t)(clockid_t clk_id, struct timespec *ts);
+typedef time_t (*vdso_time_t)(time_t *t);
+
+static int vdso_test_gettimeofday(void)
+{
+	/* Find gettimeofday. */
+	vdso_gettimeofday_t vdso_gettimeofday =
+		(vdso_gettimeofday_t)vdso_sym(version, name[0]);
+
+	if (!vdso_gettimeofday) {
+		printf("Could not find %s\n", name[0]);
+		return KSFT_SKIP;
+	}
+
+	struct timeval tv;
+	long ret = vdso_gettimeofday(&tv, 0);
+
+	if (ret == 0) {
+		printf("The time is %lld.%06lld\n",
+		       (long long)tv.tv_sec, (long long)tv.tv_usec);
+	} else {
+		printf("%s failed\n", name[0]);
+		return KSFT_FAIL;
+	}
+
+	return KSFT_PASS;
+}
+
+static int vdso_test_clock_gettime(clockid_t clk_id)
+{
+	/* Find clock_gettime. */
+	vdso_clock_gettime_t vdso_clock_gettime =
+		(vdso_clock_gettime_t)vdso_sym(version, name[1]);
+
+	if (!vdso_clock_gettime) {
+		printf("Could not find %s\n", name[1]);
+		return KSFT_SKIP;
+	}
+
+	struct timespec ts;
+	long ret = vdso_clock_gettime(clk_id, &ts);
+
+	if (ret == 0) {
+		printf("The time is %lld.%06lld\n",
+		       (long long)ts.tv_sec, (long long)ts.tv_nsec);
+	} else {
+		printf("%s failed\n", name[1]);
+		return KSFT_FAIL;
+	}
+
+	return KSFT_PASS;
+}
+
+static int vdso_test_time(void)
+{
+	/* Find time. */
+	vdso_time_t vdso_time =
+		(vdso_time_t)vdso_sym(version, name[2]);
+
+	if (!vdso_time) {
+		printf("Could not find %s\n", name[2]);
+		return KSFT_SKIP;
+	}
+
+	long ret = vdso_time(NULL);
+
+	if (ret > 0) {
+		printf("The time in hours since January 1, 1970 is %lld\n",
+				(long long)(ret / 3600));
+	} else {
+		printf("%s failed\n", name[2]);
+		return KSFT_FAIL;
+	}
+
+	return KSFT_PASS;
+}
+
+static int vdso_test_clock_getres(clockid_t clk_id)
+{
+	/* Find clock_getres. */
+	vdso_clock_getres_t vdso_clock_getres =
+		(vdso_clock_getres_t)vdso_sym(version, name[3]);
+
+	if (!vdso_clock_getres) {
+		printf("Could not find %s\n", name[3]);
+		return KSFT_SKIP;
+	}
+
+	struct timespec ts, sys_ts;
+	long ret = vdso_clock_getres(clk_id, &ts);
+
+	if (ret == 0) {
+		printf("The resolution is %lld %lld\n",
+		       (long long)ts.tv_sec, (long long)ts.tv_nsec);
+	} else {
+		printf("%s failed\n", name[3]);
+		return KSFT_FAIL;
+	}
+
+	ret = syscall(SYS_clock_getres, clk_id, &sys_ts);
+
+	if ((sys_ts.tv_sec != ts.tv_sec) || (sys_ts.tv_nsec != ts.tv_nsec)) {
+		printf("%s failed\n", name[3]);
+		return KSFT_FAIL;
+	}
+
+	return KSFT_PASS;
+}
+
+const char *vdso_clock_name[12] = {
+	"CLOCK_REALTIME",
+	"CLOCK_MONOTONIC",
+	"CLOCK_PROCESS_CPUTIME_ID",
+	"CLOCK_THREAD_CPUTIME_ID",
+	"CLOCK_MONOTONIC_RAW",
+	"CLOCK_REALTIME_COARSE",
+	"CLOCK_MONOTONIC_COARSE",
+	"CLOCK_BOOTTIME",
+	"CLOCK_REALTIME_ALARM",
+	"CLOCK_BOOTTIME_ALARM",
+	"CLOCK_SGI_CYCLE",
+	"CLOCK_TAI",
+};
+
+/*
+ * This function calls vdso_test_clock_gettime and vdso_test_clock_getres
+ * with different values for clock_id.
+ */
+static inline int vdso_test_clock(clockid_t clock_id)
+{
+	int ret0, ret1;
+
+	ret0 = vdso_test_clock_gettime(clock_id);
+	/* A skipped test is considered passed */
+	if (ret0 == KSFT_SKIP)
+		ret0 = KSFT_PASS;
+
+	ret1 = vdso_test_clock_getres(clock_id);
+	/* A skipped test is considered passed */
+	if (ret1 == KSFT_SKIP)
+		ret1 = KSFT_PASS;
+
+	ret0 += ret1;
+
+	printf("clock_id: %s", vdso_clock_name[clock_id]);
+
+	if (ret0 > 0)
+		printf(" [FAIL]\n");
+	else
+		printf(" [PASS]\n");
+
+	return ret0;
+}
+
+int main(int argc, char **argv)
+{
+	unsigned long sysinfo_ehdr = getauxval(AT_SYSINFO_EHDR);
+	int ret;
+
+	if (!sysinfo_ehdr) {
+		printf("AT_SYSINFO_EHDR is not present!\n");
+		return KSFT_SKIP;
+	}
+
+	version = versions[VDSO_VERSION];
+	name = (const char **)&names[VDSO_NAMES];
+
+	printf("[vDSO kselftest] VDSO_VERSION: %s\n", version);
+
+	vdso_init_from_sysinfo_ehdr(getauxval(AT_SYSINFO_EHDR));
+
+	ret = vdso_test_gettimeofday();
+
+#if _POSIX_TIMERS > 0
+
+#ifdef CLOCK_REALTIME
+	ret += vdso_test_clock(CLOCK_REALTIME);
+#endif
+
+#ifdef CLOCK_BOOTTIME
+	ret += vdso_test_clock(CLOCK_BOOTTIME);
+#endif
+
+#ifdef CLOCK_TAI
+	ret += vdso_test_clock(CLOCK_TAI);
+#endif
+
+#ifdef CLOCK_REALTIME_COARSE
+	ret += vdso_test_clock(CLOCK_REALTIME_COARSE);
+#endif
+
+#ifdef CLOCK_MONOTONIC
+	ret += vdso_test_clock(CLOCK_MONOTONIC);
+#endif
+
+#ifdef CLOCK_MONOTONIC_RAW
+	ret += vdso_test_clock(CLOCK_MONOTONIC_RAW);
+#endif
+
+#ifdef CLOCK_MONOTONIC_COARSE
+	ret += vdso_test_clock(CLOCK_MONOTONIC_COARSE);
+#endif
+
+#endif
+
+	ret += vdso_test_time();
+
+	if (ret > 0)
+		return KSFT_FAIL;
+
+	return KSFT_PASS;
+}
-- 
2.25.2

[PATCH 3/3] kselftest: Extend vDSO selftest to clock_getres

[Vincenzo Frascino]

The current version of the multiarch vDSO selftest verifies only
gettimeofday.

Extend the vDSO selftest to clock_getres, to verify that the
syscall and the vDSO library function return the same information.

The extension has been used to verify the hrtimer_resoltion fix.

Cc: Shuah Khan <shuah@kernel.org>
Signed-off-by: Vincenzo Frascino <vincenzo.frascino@arm.com>
---
 tools/testing/selftests/vDSO/Makefile         |   2 +
 .../selftests/vDSO/vdso_clock_getres.c        | 124 ++++++++++++++++++
 2 files changed, 126 insertions(+)
 create mode 100644 tools/testing/selftests/vDSO/vdso_clock_getres.c

diff --git a/tools/testing/selftests/vDSO/Makefile b/tools/testing/selftests/vDSO/Makefile
index 46aab4eaccbd..7b096eedfd5d 100644
--- a/tools/testing/selftests/vDSO/Makefile
+++ b/tools/testing/selftests/vDSO/Makefile
@@ -6,6 +6,7 @@ ARCH ?= $(shell echo $(uname_M) | sed -e s/i.86/x86/ -e s/x86_64/x86/)
 
 TEST_GEN_PROGS := $(OUTPUT)/vdso_test
 TEST_GEN_PROGS += $(OUTPUT)/vdso_full_test
+TEST_GEN_PROGS += $(OUTPUT)/vdso_clock_getres
 ifeq ($(ARCH),x86)
 TEST_GEN_PROGS += $(OUTPUT)/vdso_standalone_test_x86
 endif
@@ -19,6 +20,7 @@ endif
 all: $(TEST_GEN_PROGS)
 $(OUTPUT)/vdso_test: parse_vdso.c vdso_test.c
 $(OUTPUT)/vdso_full_test: parse_vdso.c vdso_full_test.c
+$(OUTPUT)/vdso_clock_getres: vdso_clock_getres.c
 $(OUTPUT)/vdso_standalone_test_x86: vdso_standalone_test_x86.c parse_vdso.c
 	$(CC) $(CFLAGS) $(CFLAGS_vdso_standalone_test_x86) \
 		vdso_standalone_test_x86.c parse_vdso.c \
diff --git a/tools/testing/selftests/vDSO/vdso_clock_getres.c b/tools/testing/selftests/vDSO/vdso_clock_getres.c
new file mode 100644
index 000000000000..15dcee16ff72
--- /dev/null
+++ b/tools/testing/selftests/vDSO/vdso_clock_getres.c
@@ -0,0 +1,124 @@
+// SPDX-License-Identifier: GPL-2.0 WITH Linux-syscall-note
+/*
+ * vdso_clock_getres.c: Sample code to test clock_getres.
+ * Copyright (c) 2019 Arm Ltd.
+ *
+ * Compile with:
+ * gcc -std=gnu99 vdso_clock_getres.c
+ *
+ * Tested on ARM, ARM64, MIPS32, x86 (32-bit and 64-bit),
+ * Power (32-bit and 64-bit), S390x (32-bit and 64-bit).
+ * Might work on other architectures.
+ */
+
+#define _GNU_SOURCE
+#include <elf.h>
+#include <err.h>
+#include <fcntl.h>
+#include <stdint.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <time.h>
+#include <sys/auxv.h>
+#include <sys/mman.h>
+#include <sys/time.h>
+#include <unistd.h>
+#include <sys/syscall.h>
+
+#include "../kselftest.h"
+
+static long syscall_clock_getres(clockid_t _clkid, struct timespec *_ts)
+{
+	long ret;
+
+	ret = syscall(SYS_clock_getres, _clkid, _ts);
+
+	return ret;
+}
+
+const char *vdso_clock_name[12] = {
+	"CLOCK_REALTIME",
+	"CLOCK_MONOTONIC",
+	"CLOCK_PROCESS_CPUTIME_ID",
+	"CLOCK_THREAD_CPUTIME_ID",
+	"CLOCK_MONOTONIC_RAW",
+	"CLOCK_REALTIME_COARSE",
+	"CLOCK_MONOTONIC_COARSE",
+	"CLOCK_BOOTTIME",
+	"CLOCK_REALTIME_ALARM",
+	"CLOCK_BOOTTIME_ALARM",
+	"CLOCK_SGI_CYCLE",
+	"CLOCK_TAI",
+};
+
+/*
+ * This function calls clock_getres in vdso and by system call
+ * with different values for clock_id.
+ *
+ * Example of output:
+ *
+ * clock_id: CLOCK_REALTIME [PASS]
+ * clock_id: CLOCK_BOOTTIME [PASS]
+ * clock_id: CLOCK_TAI [PASS]
+ * clock_id: CLOCK_REALTIME_COARSE [PASS]
+ * clock_id: CLOCK_MONOTONIC [PASS]
+ * clock_id: CLOCK_MONOTONIC_RAW [PASS]
+ * clock_id: CLOCK_MONOTONIC_COARSE [PASS]
+ */
+static inline int vdso_test_clock(unsigned int clock_id)
+{
+	struct timespec x, y;
+
+	printf("clock_id: %s", vdso_clock_name[clock_id]);
+	clock_getres(clock_id, &x);
+	syscall_clock_getres(clock_id, &y);
+
+	if ((x.tv_sec != y.tv_sec) || (x.tv_nsec != y.tv_nsec)) {
+		printf(" [FAIL]\n");
+		return KSFT_FAIL;
+	}
+
+	printf(" [PASS]\n");
+	return KSFT_PASS;
+}
+
+int main(int argc, char **argv)
+{
+	int ret;
+
+#if _POSIX_TIMERS > 0
+
+#ifdef CLOCK_REALTIME
+	ret = vdso_test_clock(CLOCK_REALTIME);
+#endif
+
+#ifdef CLOCK_BOOTTIME
+	ret += vdso_test_clock(CLOCK_BOOTTIME);
+#endif
+
+#ifdef CLOCK_TAI
+	ret += vdso_test_clock(CLOCK_TAI);
+#endif
+
+#ifdef CLOCK_REALTIME_COARSE
+	ret += vdso_test_clock(CLOCK_REALTIME_COARSE);
+#endif
+
+#ifdef CLOCK_MONOTONIC
+	ret += vdso_test_clock(CLOCK_MONOTONIC);
+#endif
+
+#ifdef CLOCK_MONOTONIC_RAW
+	ret += vdso_test_clock(CLOCK_MONOTONIC_RAW);
+#endif
+
+#ifdef CLOCK_MONOTONIC_COARSE
+	ret += vdso_test_clock(CLOCK_MONOTONIC_COARSE);
+#endif
+
+#endif
+	if (ret > 0)
+		return KSFT_FAIL;
+
+	return KSFT_PASS;
+}
-- 
2.25.2

Re: [PATCH 2/3] kselftest: Extend vDSO selftest

[Andy Lutomirski]

On Tue, Mar 24, 2020 at 7:51 AM Vincenzo Frascino
<vincenzo.frascino@arm.com> wrote:
>
> The current version of the multiarch vDSO selftest verifies only
> gettimeofday.
>
> Extend the vDSO selftest to the other library functions:
>  - time
>  - clock_getres
>  - clock_gettime
>
> The extension has been used to verify the unified vdso library on the
> supported architectures.

The code in tools/testing/selftests/x86/test_vdso.c actually checks
that the times returned by the vDSO are correct.  Perhaps that code
should be copied or moved here?

Re: [PATCH 2/3] kselftest: Extend vDSO selftest

[Vincenzo Frascino]

Hi Andy,

On 3/24/20 5:22 PM, Andy Lutomirski wrote:
> On Tue, Mar 24, 2020 at 7:51 AM Vincenzo Frascino
> <vincenzo.frascino@arm.com> wrote:
>>
>> The current version of the multiarch vDSO selftest verifies only
>> gettimeofday.
>>
>> Extend the vDSO selftest to the other library functions:
>>  - time
>>  - clock_getres
>>  - clock_gettime
>>
>> The extension has been used to verify the unified vdso library on the
>> supported architectures.
> 
> The code in tools/testing/selftests/x86/test_vdso.c actually checks
> that the times returned by the vDSO are correct.  Perhaps that code
> should be copied or moved here?
> 

Good point. I was not aware of such a test. I will definitely move it here and
make sure it works for non x86 platforms as well in the next iteration of this
series.

-- 
Regards,
Vincenzo