[RFC v2 2/4] selftests: futex: Add futex2 wake/wait test
From: Andrà Almeida
Date: Thu Jul 09 2020 - 14:00:52 EST
Add a simple test to test wake/wait mechanism using futex2 interface.
Create helper files so more tests can evaluate futex2. While 32bit ABIs
from glibc aren't able to use 64 bit sized time variables, add a
temporary workaround that implements the required types and calls the
appropriated syscalls, since futex2 doesn't supports 32 bit sized time.
Signed-off-by: Andrà Almeida <andrealmeid@xxxxxxxxxxxxx>
---
tools/include/uapi/asm-generic/unistd.h | 7 +-
.../selftests/futex/functional/.gitignore | 1 +
.../selftests/futex/functional/Makefile | 4 +-
.../selftests/futex/functional/futex2_wait.c | 111 ++++++++++++++++++
.../testing/selftests/futex/functional/run.sh | 3 +
.../selftests/futex/include/futex2test.h | 77 ++++++++++++
6 files changed, 201 insertions(+), 2 deletions(-)
create mode 100644 tools/testing/selftests/futex/functional/futex2_wait.c
create mode 100644 tools/testing/selftests/futex/include/futex2test.h
diff --git a/tools/include/uapi/asm-generic/unistd.h b/tools/include/uapi/asm-generic/unistd.h
index 3a3201e4618e..40fbf4ce49ff 100644
--- a/tools/include/uapi/asm-generic/unistd.h
+++ b/tools/include/uapi/asm-generic/unistd.h
@@ -856,8 +856,13 @@ __SYSCALL(__NR_openat2, sys_openat2)
#define __NR_pidfd_getfd 438
__SYSCALL(__NR_pidfd_getfd, sys_pidfd_getfd)
+#define __NR_futex_wait 440
+__SYSCALL(__NR_futex_wait, sys_futex_wait)
+#define __NR_futex_wake 441
+__SYSCALL(__NR_futex_wake, sys_futex_wake)
+
#undef __NR_syscalls
-#define __NR_syscalls 439
+#define __NR_syscalls 442
/*
* 32 bit systems traditionally used different
diff --git a/tools/testing/selftests/futex/functional/.gitignore b/tools/testing/selftests/futex/functional/.gitignore
index 0efcd494daab..d61f1df94360 100644
--- a/tools/testing/selftests/futex/functional/.gitignore
+++ b/tools/testing/selftests/futex/functional/.gitignore
@@ -6,3 +6,4 @@ futex_wait_private_mapped_file
futex_wait_timeout
futex_wait_uninitialized_heap
futex_wait_wouldblock
+futex2_wait
diff --git a/tools/testing/selftests/futex/functional/Makefile b/tools/testing/selftests/futex/functional/Makefile
index 23207829ec75..7142a94a7ac3 100644
--- a/tools/testing/selftests/futex/functional/Makefile
+++ b/tools/testing/selftests/futex/functional/Makefile
@@ -5,6 +5,7 @@ LDLIBS := -lpthread -lrt
HEADERS := \
../include/futextest.h \
+ ../include/futex2test.h \
../include/atomic.h \
../include/logging.h
TEST_GEN_FILES := \
@@ -14,7 +15,8 @@ TEST_GEN_FILES := \
futex_requeue_pi_signal_restart \
futex_requeue_pi_mismatched_ops \
futex_wait_uninitialized_heap \
- futex_wait_private_mapped_file
+ futex_wait_private_mapped_file \
+ futex2_wait
TEST_PROGS := run.sh
diff --git a/tools/testing/selftests/futex/functional/futex2_wait.c b/tools/testing/selftests/futex/functional/futex2_wait.c
new file mode 100644
index 000000000000..752ed26803b3
--- /dev/null
+++ b/tools/testing/selftests/futex/functional/futex2_wait.c
@@ -0,0 +1,111 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/******************************************************************************
+ *
+ * Copyright Collabora Ltd., 2020
+ *
+ * DESCRIPTION
+ * Test wait/wake mechanism of futex2, using 32bit sized futexes.
+ *
+ * AUTHOR
+ * Andrà Almeida <andrealmeid@xxxxxxxxxxxxx>
+ *
+ * HISTORY
+ * 2020-Jul-9: Initial version by Andrà <andrealmeid@xxxxxxxxxxxxx>
+ *
+ *****************************************************************************/
+
+#include <errno.h>
+#include <error.h>
+#include <getopt.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <time.h>
+#include <pthread.h>
+#include "futex2test.h"
+#include "logging.h"
+
+#define TEST_NAME "futex-wait-wouldblock"
+#define timeout_ns 30000000
+#define WAKE_WAIT_US 10000
+futex_t f1 = FUTEX_INITIALIZER;
+
+void usage(char *prog)
+{
+ printf("Usage: %s\n", prog);
+ printf(" -c Use color\n");
+ printf(" -h Display this help message\n");
+ printf(" -v L Verbosity level: %d=QUIET %d=CRITICAL %d=INFO\n",
+ VQUIET, VCRITICAL, VINFO);
+}
+
+void *waiterfn(void *arg)
+{
+ struct timespec64 to64;
+
+ /* setting absolute timeout for futex2 */
+ if (gettime64(CLOCK_MONOTONIC, &to64))
+ error("gettime64 failed\n", errno);
+
+ to64.tv_nsec += timeout_ns;
+
+ if (to64.tv_nsec >= 1000000000) {
+ to64.tv_sec++;
+ to64.tv_nsec -= 1000000000;
+ }
+
+ if (futex2_wait(&f1, f1, FUTEX_PRIVATE_FLAG | FUTEX_32, &to64))
+ printf("waiter failed errno %d\n", errno);
+
+ return NULL;
+}
+
+int main(int argc, char *argv[])
+{
+ pthread_t waiter;
+ int res, ret = RET_PASS;
+ int c;
+
+ while ((c = getopt(argc, argv, "cht:v:")) != -1) {
+ switch (c) {
+ case 'c':
+ log_color(1);
+ break;
+ case 'h':
+ usage(basename(argv[0]));
+ exit(0);
+ case 'v':
+ log_verbosity(atoi(optarg));
+ break;
+ default:
+ usage(basename(argv[0]));
+ exit(1);
+ }
+ }
+
+ ksft_print_header();
+ ksft_set_plan(1);
+ ksft_print_msg("%s: Test FUTEX_WAIT\n",
+ basename(argv[0]));
+
+ info("Calling futex_wait on f1: %u @ %p with val=%u\n", f1, &f1, f1);
+
+ if (pthread_create(&waiter, NULL, waiterfn, NULL))
+ error("pthread_create failed\n", errno);
+
+ usleep(WAKE_WAIT_US);
+
+ info("Calling futex2_wake on f1: %u @ %p with val=%u\n", f1, &f1, f1);
+ res = futex2_wake(&f1, 1, FUTEX_PRIVATE_FLAG | FUTEX_32);
+ if (res != 1) {
+ ksft_test_result_fail("futex2_wake returned: %d %s\n",
+ res ? errno : res,
+ res ? strerror(errno) : "");
+ ret = RET_FAIL;
+ } else {
+ ksft_test_result_pass("futex2_wake wouldblock succeeds\n");
+ }
+
+ ksft_print_cnts();
+ return ret;
+}
diff --git a/tools/testing/selftests/futex/functional/run.sh b/tools/testing/selftests/futex/functional/run.sh
index 1acb6ace1680..3730159c865a 100755
--- a/tools/testing/selftests/futex/functional/run.sh
+++ b/tools/testing/selftests/futex/functional/run.sh
@@ -73,3 +73,6 @@ echo
echo
./futex_wait_uninitialized_heap $COLOR
./futex_wait_private_mapped_file $COLOR
+
+echo
+./futex2_wait $COLOR
diff --git a/tools/testing/selftests/futex/include/futex2test.h b/tools/testing/selftests/futex/include/futex2test.h
new file mode 100644
index 000000000000..807b8b57fe61
--- /dev/null
+++ b/tools/testing/selftests/futex/include/futex2test.h
@@ -0,0 +1,77 @@
+/* SPDX-License-Identifier: GPL-2.0-or-later */
+/******************************************************************************
+ *
+ * Copyright Collabora Ltd., 2020
+ *
+ * DESCRIPTION
+ * Futex2 library addons for old futex library
+ *
+ * AUTHOR
+ * Andrà Almeida <andrealmeid@xxxxxxxxxxxxx>
+ *
+ * HISTORY
+ * 2020-Jul-9: Initial version by Andrà <andrealmeid@xxxxxxxxxxxxx>
+ *
+ *****************************************************************************/
+#include "futextest.h"
+#include <stdio.h>
+
+#define NSEC_PER_SEC 1000000000L
+
+#ifndef FUTEX_8
+# define FUTEX_8 0
+#endif
+#ifndef FUTEX_16
+# define FUTEX_16 1
+#endif
+#ifndef FUTEX_32
+#define FUTEX_32 2
+#endif
+#ifdef __x86_64__
+# ifndef FUTEX_64
+# define FUTEX_64 3
+# endif
+#endif
+
+/*
+ * - Y2038 section for 32-bit applications -
+ *
+ * Remove this when glibc is ready for y2038. Then, always compile with
+ * `-DTIME_BITS=64` or `-D__USE_TIME_BITS64`. glibc will provide both
+ * timespec64 and clock_gettime64 so we won't need to define here.
+ */
+#if defined(__i386__) || __TIMESIZE == 32
+# define NR_gettime __NR_clock_gettime64
+#else
+# define NR_gettime __NR_clock_gettime
+#endif
+
+struct timespec64 {
+ long long tv_sec; /* seconds */
+ long long tv_nsec; /* nanoseconds */
+};
+
+int gettime64(clock_t clockid, struct timespec64 *tv)
+{
+ return syscall(NR_gettime, clockid, tv);
+}
+/*
+ * - End of Y2038 section -
+ */
+
+/*
+ * wait for uaddr if (*uaddr == val)
+ */
+static inline int futex2_wait(volatile void *uaddr, unsigned long val,
+ unsigned long flags, struct timespec64 *timo)
+{
+ return syscall(__NR_futex_wait, uaddr, val, flags, timo);
+}
+
+/*
+ * wake nr futexes waiting for uaddr
+ */
+static inline int futex2_wake(volatile void *uaddr, unsigned int nr, unsigned long flags)
+{
+ return syscall(__NR_futex_wake, uaddr, nr, flags);
+}
--
2.27.0