[PATCH v2 14/14] futex,selftests: Extend the futex selftests

From: Peter Zijlstra
Date: Mon Aug 07 2023 - 08:38:19 EST

Extend the wait/requeue selftests to also cover the futex2 syscalls.

Signed-off-by: Peter Zijlstra (Intel) <peterz@xxxxxxxxxxxxx>
---
tools/testing/selftests/futex/functional/futex_requeue.c | 100 +++++++++-
tools/testing/selftests/futex/functional/futex_wait.c | 56 ++++-
tools/testing/selftests/futex/functional/futex_wait_timeout.c | 14 +
tools/testing/selftests/futex/functional/futex_wait_wouldblock.c | 28 ++
tools/testing/selftests/futex/functional/futex_waitv.c | 15 -
tools/testing/selftests/futex/functional/run.sh | 6
tools/testing/selftests/futex/include/futex2test.h | 39 +++
7 files changed, 229 insertions(+), 29 deletions(-)

--- a/tools/testing/selftests/futex/functional/futex_requeue.c
+++ b/tools/testing/selftests/futex/functional/futex_requeue.c
@@ -7,8 +7,10 @@

#include <pthread.h>
#include <limits.h>
+#include <stdbool.h>
#include "logging.h"
#include "futextest.h"
+#include "futex2test.h"

#define TEST_NAME "futex-requeue"
#define timeout_ns 30000000
@@ -16,24 +18,58 @@

volatile futex_t *f1;

+bool futex2 = 0;
+bool mixed = 0;
+
void usage(char *prog)
{
printf("Usage: %s\n", prog);
printf(" -c Use color\n");
+ printf(" -n Use futex2 interface\n");
+ printf(" -x Use mixed size futex\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)
+static void *waiterfn(void *arg)
{
+ unsigned int flags = 0;
struct timespec to;

- to.tv_sec = 0;
- to.tv_nsec = timeout_ns;
+ if (futex2) {
+ unsigned long mask;
+
+ if (clock_gettime(CLOCK_MONOTONIC, &to)) {
+ printf("clock_gettime() failed errno %d", errno);
+ return NULL;
+ }
+
+ to.tv_nsec += timeout_ns;
+ if (to.tv_nsec >= 1000000000) {
+ to.tv_sec++;
+ to.tv_nsec -= 1000000000;
+ }
+
+ if (mixed) {
+ flags |= FUTEX2_SIZE_U16;
+ mask = (unsigned short)(~0U);
+ } else {
+ flags |= FUTEX2_SIZE_U32;
+ mask = (unsigned int)(~0U);
+ }
+
+ if (futex2_wait(f1, *f1, mask, flags,
+ &to, CLOCK_MONOTONIC))
+ printf("waiter failed errno %d\n", errno);
+ } else {
+
+ to.tv_sec = 0;
+ to.tv_nsec = timeout_ns;

- if (futex_wait(f1, *f1, &to, 0))
- printf("waiter failed errno %d\n", errno);
+ if (futex_wait(f1, *f1, &to, flags))
+ printf("waiter failed errno %d\n", errno);
+ }

return NULL;
}
@@ -48,7 +84,7 @@ int main(int argc, char *argv[])

f1 = &_f1;

- while ((c = getopt(argc, argv, "cht:v:")) != -1) {
+ while ((c = getopt(argc, argv, "xncht:v:")) != -1) {
switch (c) {
case 'c':
log_color(1);
@@ -59,6 +95,12 @@ int main(int argc, char *argv[])
case 'v':
log_verbosity(atoi(optarg));
break;
+ case 'x':
+ mixed=1;
+ /* fallthrough */
+ case 'n':
+ futex2=1;
+ break;
default:
usage(basename(argv[0]));
exit(1);
@@ -79,7 +121,22 @@ int main(int argc, char *argv[])
usleep(WAKE_WAIT_US);

info("Requeuing 1 futex from f1 to f2\n");
- res = futex_cmp_requeue(f1, 0, &f2, 0, 1, 0);
+ if (futex2) {
+ struct futex_waitv futexes[2] = {
+ {
+ .val = 0,
+ .uaddr = (unsigned long)f1,
+ .flags = mixed ? FUTEX2_SIZE_U16 : FUTEX2_SIZE_U32,
+ },
+ {
+ .uaddr = (unsigned long)&f2,
+ .flags = FUTEX2_SIZE_U32,
+ },
+ };
+ res = futex2_requeue(futexes, 0, 0, 1);
+ } else {
+ res = futex_cmp_requeue(f1, 0, &f2, 0, 1, 0);
+ }
if (res != 1) {
ksft_test_result_fail("futex_requeue simple returned: %d %s\n",
res ? errno : res,
@@ -89,7 +146,11 @@ int main(int argc, char *argv[])


info("Waking 1 futex at f2\n");
- res = futex_wake(&f2, 1, 0);
+ if (futex2) {
+ res = futex2_wake(&f2, ~0U, 1, FUTEX2_SIZE_U32);
+ } else {
+ res = futex_wake(&f2, 1, 0);
+ }
if (res != 1) {
ksft_test_result_fail("futex_requeue simple returned: %d %s\n",
res ? errno : res,
@@ -112,7 +173,22 @@ int main(int argc, char *argv[])
usleep(WAKE_WAIT_US);

info("Waking 3 futexes at f1 and requeuing 7 futexes from f1 to f2\n");
- res = futex_cmp_requeue(f1, 0, &f2, 3, 7, 0);
+ if (futex2) {
+ struct futex_waitv futexes[2] = {
+ {
+ .val = 0,
+ .uaddr = (unsigned long)f1,
+ .flags = mixed ? FUTEX2_SIZE_U16 : FUTEX2_SIZE_U32,
+ },
+ {
+ .uaddr = (unsigned long)&f2,
+ .flags = FUTEX2_SIZE_U32,
+ },
+ };
+ res = futex2_requeue(futexes, 0, 3, 7);
+ } else {
+ res = futex_cmp_requeue(f1, 0, &f2, 3, 7, 0);
+ }
if (res != 10) {
ksft_test_result_fail("futex_requeue many returned: %d %s\n",
res ? errno : res,
@@ -121,7 +197,11 @@ int main(int argc, char *argv[])
}

info("Waking INT_MAX futexes at f2\n");
- res = futex_wake(&f2, INT_MAX, 0);
+ if (futex2) {
+ res = futex2_wake(&f2, ~0U, INT_MAX, FUTEX2_SIZE_U32);
+ } else {
+ res = futex_wake(&f2, INT_MAX, 0);
+ }
if (res != 7) {
ksft_test_result_fail("futex_requeue many returned: %d %s\n",
res ? errno : res,
--- a/tools/testing/selftests/futex/functional/futex_wait.c
+++ b/tools/testing/selftests/futex/functional/futex_wait.c
@@ -9,8 +9,10 @@
#include <sys/shm.h>
#include <sys/mman.h>
#include <fcntl.h>
+#include <stdbool.h>
#include "logging.h"
#include "futextest.h"
+#include "futex2test.h"

#define TEST_NAME "futex-wait"
#define timeout_ns 30000000
@@ -19,10 +21,13 @@

void *futex;

+bool futex2 = 0;
+
void usage(char *prog)
{
printf("Usage: %s\n", prog);
printf(" -c Use color\n");
+ printf(" -n Use futex2 interface\n");
printf(" -h Display this help message\n");
printf(" -v L Verbosity level: %d=QUIET %d=CRITICAL %d=INFO\n",
VQUIET, VCRITICAL, VINFO);
@@ -30,17 +35,35 @@ void usage(char *prog)

static void *waiterfn(void *arg)
{
- struct timespec to;
unsigned int flags = 0;
+ struct timespec to;

if (arg)
flags = *((unsigned int *) arg);

- to.tv_sec = 0;
- to.tv_nsec = timeout_ns;
+ if (futex2) {
+ if (clock_gettime(CLOCK_MONOTONIC, &to)) {
+ printf("clock_gettime() failed errno %d", errno);
+ return NULL;
+ }

- if (futex_wait(futex, 0, &to, flags))
- printf("waiter failed errno %d\n", errno);
+ to.tv_nsec += timeout_ns;
+ if (to.tv_nsec >= 1000000000) {
+ to.tv_sec++;
+ to.tv_nsec -= 1000000000;
+ }
+
+ if (futex2_wait(futex, 0, ~0U, flags | FUTEX2_SIZE_U32,
+ &to, CLOCK_MONOTONIC))
+ printf("waiter failed errno %d\n", errno);
+ } else {
+
+ to.tv_sec = 0;
+ to.tv_nsec = timeout_ns;
+
+ if (futex_wait(futex, 0, &to, flags))
+ printf("waiter failed errno %d\n", errno);
+ }

return NULL;
}
@@ -55,7 +78,7 @@ int main(int argc, char *argv[])

futex = &f_private;

- while ((c = getopt(argc, argv, "cht:v:")) != -1) {
+ while ((c = getopt(argc, argv, "ncht:v:")) != -1) {
switch (c) {
case 'c':
log_color(1);
@@ -66,6 +89,9 @@ int main(int argc, char *argv[])
case 'v':
log_verbosity(atoi(optarg));
break;
+ case 'n':
+ futex2=1;
+ break;
default:
usage(basename(argv[0]));
exit(1);
@@ -84,7 +110,11 @@ int main(int argc, char *argv[])
usleep(WAKE_WAIT_US);

info("Calling private futex_wake on futex: %p\n", futex);
- res = futex_wake(futex, 1, FUTEX_PRIVATE_FLAG);
+ if (futex2) {
+ res = futex2_wake(futex, ~0U, 1, FUTEX2_SIZE_U32 | FUTEX2_PRIVATE);
+ } else {
+ res = futex_wake(futex, 1, FUTEX_PRIVATE_FLAG);
+ }
if (res != 1) {
ksft_test_result_fail("futex_wake private returned: %d %s\n",
errno, strerror(errno));
@@ -112,7 +142,11 @@ int main(int argc, char *argv[])
usleep(WAKE_WAIT_US);

info("Calling shared (page anon) futex_wake on futex: %p\n", futex);
- res = futex_wake(futex, 1, 0);
+ if (futex2) {
+ res = futex2_wake(futex, ~0U, 1, FUTEX2_SIZE_U32);
+ } else {
+ res = futex_wake(futex, 1, 0);
+ }
if (res != 1) {
ksft_test_result_fail("futex_wake shared (page anon) returned: %d %s\n",
errno, strerror(errno));
@@ -151,7 +185,11 @@ int main(int argc, char *argv[])
usleep(WAKE_WAIT_US);

info("Calling shared (file backed) futex_wake on futex: %p\n", futex);
- res = futex_wake(shm, 1, 0);
+ if (futex2) {
+ res = futex2_wake(shm, ~0U, 1, FUTEX2_SIZE_U32);
+ } else {
+ res = futex_wake(shm, 1, 0);
+ }
if (res != 1) {
ksft_test_result_fail("futex_wake shared (file backed) returned: %d %s\n",
errno, strerror(errno));
--- a/tools/testing/selftests/futex/functional/futex_wait_timeout.c
+++ b/tools/testing/selftests/futex/functional/futex_wait_timeout.c
@@ -125,7 +125,7 @@ int main(int argc, char *argv[])
}

ksft_print_header();
- ksft_set_plan(9);
+ ksft_set_plan(11);
ksft_print_msg("%s: Block on a futex and wait for timeout\n",
basename(argv[0]));
ksft_print_msg("\tArguments: timeout=%ldns\n", timeout_ns);
@@ -194,6 +194,18 @@ int main(int argc, char *argv[])
res = futex_waitv(&waitv, 1, 0, &to, CLOCK_REALTIME);
test_timeout(res, &ret, "futex_waitv realtime", ETIMEDOUT);

+ /* futex2_wait with CLOCK_MONOTONIC */
+ if (futex_get_abs_timeout(CLOCK_MONOTONIC, &to, timeout_ns))
+ return RET_FAIL;
+ res = futex2_wait(&f1, f1, 1, FUTEX2_SIZE_U32, &to, CLOCK_MONOTONIC);
+ test_timeout(res, &ret, "futex2_wait monotonic", ETIMEDOUT);
+
+ /* futex2_wait with CLOCK_REALTIME */
+ if (futex_get_abs_timeout(CLOCK_REALTIME, &to, timeout_ns))
+ return RET_FAIL;
+ res = futex2_wait(&f1, f1, 1, FUTEX2_SIZE_U32, &to, CLOCK_REALTIME);
+ test_timeout(res, &ret, "futex2_wait realtime", ETIMEDOUT);
+
ksft_print_cnts();
return ret;
}
--- a/tools/testing/selftests/futex/functional/futex_wait_wouldblock.c
+++ b/tools/testing/selftests/futex/functional/futex_wait_wouldblock.c
@@ -46,7 +46,7 @@ int main(int argc, char *argv[])
struct futex_waitv waitv = {
.uaddr = (uintptr_t)&f1,
.val = f1+1,
- .flags = FUTEX_32,
+ .flags = FUTEX2_SIZE_U32 | FUTEX2_PRIVATE,
.__reserved = 0
};

@@ -68,7 +68,7 @@ int main(int argc, char *argv[])
}

ksft_print_header();
- ksft_set_plan(2);
+ ksft_set_plan(3);
ksft_print_msg("%s: Test the unexpected futex value in FUTEX_WAIT\n",
basename(argv[0]));

@@ -106,6 +106,30 @@ int main(int argc, char *argv[])
ksft_test_result_pass("futex_waitv\n");
}

+ if (clock_gettime(CLOCK_MONOTONIC, &to)) {
+ error("clock_gettime failed\n", errno);
+ return errno;
+ }
+
+ to.tv_nsec += timeout_ns;
+
+ if (to.tv_nsec >= 1000000000) {
+ to.tv_sec++;
+ to.tv_nsec -= 1000000000;
+ }
+
+ info("Calling futex2_wait on f1: %u @ %p with val=%u\n", f1, &f1, f1+1);
+ res = futex2_wait(&f1, f1+1, ~0U, FUTEX2_SIZE_U32 | FUTEX2_PRIVATE,
+ &to, CLOCK_MONOTONIC);
+ if (!res || errno != EWOULDBLOCK) {
+ ksft_test_result_pass("futex2_wait returned: %d %s\n",
+ res ? errno : res,
+ res ? strerror(errno) : "");
+ ret = RET_FAIL;
+ } else {
+ ksft_test_result_pass("futex2_wait\n");
+ }
+
ksft_print_cnts();
return ret;
}
--- a/tools/testing/selftests/futex/functional/futex_waitv.c
+++ b/tools/testing/selftests/futex/functional/futex_waitv.c
@@ -88,7 +88,7 @@ int main(int argc, char *argv[])

for (i = 0; i < NR_FUTEXES; i++) {
waitv[i].uaddr = (uintptr_t)&futexes[i];
- waitv[i].flags = FUTEX_32 | FUTEX_PRIVATE_FLAG;
+ waitv[i].flags = FUTEX2_SIZE_U32 | FUTEX2_PRIVATE;
waitv[i].val = 0;
waitv[i].__reserved = 0;
}
@@ -99,7 +99,8 @@ int main(int argc, char *argv[])

usleep(WAKE_WAIT_US);

- res = futex_wake(u64_to_ptr(waitv[NR_FUTEXES - 1].uaddr), 1, FUTEX_PRIVATE_FLAG);
+ res = futex2_wake(u64_to_ptr(waitv[NR_FUTEXES - 1].uaddr), ~0U, 1,
+ FUTEX2_PRIVATE | FUTEX2_SIZE_U32);
if (res != 1) {
ksft_test_result_fail("futex_wake private returned: %d %s\n",
res ? errno : res,
@@ -122,7 +123,7 @@ int main(int argc, char *argv[])

*shared_data = 0;
waitv[i].uaddr = (uintptr_t)shared_data;
- waitv[i].flags = FUTEX_32;
+ waitv[i].flags = FUTEX2_SIZE_U32;
waitv[i].val = 0;
waitv[i].__reserved = 0;
}
@@ -145,8 +146,8 @@ int main(int argc, char *argv[])
for (i = 0; i < NR_FUTEXES; i++)
shmdt(u64_to_ptr(waitv[i].uaddr));

- /* Testing a waiter without FUTEX_32 flag */
- waitv[0].flags = FUTEX_PRIVATE_FLAG;
+ /* Testing a waiter without FUTEX2_SIZE_U32 flag */
+ waitv[0].flags = FUTEX2_PRIVATE;

if (clock_gettime(CLOCK_MONOTONIC, &to))
error("gettime64 failed\n", errno);
@@ -160,11 +161,11 @@ int main(int argc, char *argv[])
res ? strerror(errno) : "");
ret = RET_FAIL;
} else {
- ksft_test_result_pass("futex_waitv without FUTEX_32\n");
+ ksft_test_result_pass("futex_waitv without FUTEX2_SIZE_U32\n");
}

/* Testing a waiter with an unaligned address */
- waitv[0].flags = FUTEX_PRIVATE_FLAG | FUTEX_32;
+ waitv[0].flags = FUTEX2_PRIVATE | FUTEX2_SIZE_U32;
waitv[0].uaddr = 1;

if (clock_gettime(CLOCK_MONOTONIC, &to))
--- a/tools/testing/selftests/futex/functional/run.sh
+++ b/tools/testing/selftests/futex/functional/run.sh
@@ -76,9 +76,15 @@ echo

echo
./futex_wait $COLOR
+echo
+./futex_wait -n $COLOR

echo
./futex_requeue $COLOR
+echo
+./futex_requeue -n $COLOR
+echo
+./futex_requeue -x $COLOR

echo
./futex_waitv $COLOR
--- a/tools/testing/selftests/futex/include/futex2test.h
+++ b/tools/testing/selftests/futex/include/futex2test.h
@@ -8,6 +8,28 @@

#define u64_to_ptr(x) ((void *)(uintptr_t)(x))

+#ifndef __NR_futex_wake
+#define __NR_futex_wake 452
+#define __NR_futex_wait 453
+#define __NR_futex_requeue 454
+#endif
+
+#ifndef FUTEX2_SIZE_U8
+/*
+ * Flags for futex2 syscalls.
+ */
+#define FUTEX2_SIZE_U8 0x00
+#define FUTEX2_SIZE_U16 0x01
+#define FUTEX2_SIZE_U32 0x02
+#define FUTEX2_SIZE_U64 0x03
+#define FUTEX2_NUMA 0x04
+ /* 0x08 */
+ /* 0x10 */
+ /* 0x20 */
+ /* 0x40 */
+#define FUTEX2_PRIVATE FUTEX_PRIVATE_FLAG
+#endif
+
/**
* futex_waitv - Wait at multiple futexes, wake on any
* @waiters: Array of waiters
@@ -20,3 +42,20 @@ static inline int futex_waitv(volatile s
{
return syscall(__NR_futex_waitv, waiters, nr_waiters, flags, timo, clockid);
}
+
+static inline int futex2_wake(volatile void *uaddr, unsigned long mask, int nr, unsigned int flags)
+{
+ return syscall(__NR_futex_wake, uaddr, mask, nr, flags);
+}
+
+static inline int futex2_wait(volatile void *uaddr, unsigned long val, unsigned long mask,
+ unsigned int flags, struct timespec *timo, clockid_t clockid)
+{
+ return syscall(__NR_futex_wait, uaddr, val, mask, flags, timo, clockid);
+}
+
+static inline int futex2_requeue(struct futex_waitv *futexes, unsigned int flags,
+ int nr_wake, int nr_requeue)
+{
+ return syscall(__NR_futex_requeue, futexes, flags, nr_wake, nr_requeue);
+}