selftests: futex2: Add futex sizes test

Add a selftest for the variable size futex2 API. This initial test
just validates the basic (and correct) case, where both uses the same
size and the value is in the correct range.

Signed-off-by: André Almeida <andrealmeid@collabora.com>

tools/testing/selftests/futex/functional/.gitignore

@@ -9,3 +9,4 @@ futex_wait_wouldblock
 futex2_wait
 futex2_waitv
 futex2_requeue
+futex2_sizes

tools/testing/selftests/futex/functional/Makefile

@@ -18,7 +18,8 @@ TEST_GEN_FILES := \
 	futex_wait_private_mapped_file \
 	futex2_wait \
 	futex2_waitv \
-	futex2_requeue
+	futex2_requeue \
+	futex2_sizes
 
 TEST_PROGS := run.sh
 

tools/testing/selftests/futex/functional/futex2_sizes.c

@@ -0,0 +1,146 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/******************************************************************************
+ *
+ *   Copyright Collabora Ltd., 2021
+ *
+ * DESCRIPTION
+ *	Test wait/wake mechanism of futex2, using 32bit sized futexes.
+ *
+ * AUTHOR
+ *	André Almeida <andrealmeid@collabora.com>
+ *
+ * HISTORY
+ *      2021-Feb-5: Initial version by André <andrealmeid@collabora.com>
+ *
+ *****************************************************************************/
+
+#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 <string.h>
+#include "futex2test.h"
+#include "logging.h"
+
+#define TEST_NAME "futex2-sizes"
+
+#define futex8  uint8_t
+#define futex16 uint16_t
+#define futex32 uint32_t
+#define futex64 uint64_t
+
+// edge case values, to test sizes
+#define VALUE16 257        // 2^8  + 1
+#define VALUE32 65537      // 2^16 + 1
+#define VALUE64 4294967297 // 2^32 + 1
+
+#define WAKE_WAIT_US 100000
+
+void *futex;
+
+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);
+}
+
+struct futex {
+	unsigned long flags;
+	unsigned long val;
+};
+
+void *waiterfn(void *arg)
+{
+	int ret;
+	unsigned int *flags = (unsigned int *) arg;
+
+	ret = futex2_wait(futex, 0, *flags, NULL);
+	if (ret == ERROR)
+		error("waiter failed %d errno %d\n", ret, errno);
+
+	return NULL;
+}
+
+/*
+ * create a thread to wait, then wake it
+ */
+void test_single_waiter(unsigned int flags, int *ret)
+{
+	pthread_t waiter;
+	int res;
+
+	pthread_create(&waiter, NULL, waiterfn, &flags);
+
+	usleep(WAKE_WAIT_US);
+
+	info("Calling futex2_wake at addr %p flags %u\n", futex, flags);
+	res = futex2_wake(futex, 1, flags);
+	if (res == 1) {
+		ksft_test_result_pass("futex2_sizes\n");
+	} else {
+		ksft_test_result_fail("futex2_sizes returned: %d %s\n",
+				      errno, strerror(errno));
+		*ret = RET_FAIL;
+	}
+}
+
+int main(int argc, char *argv[])
+{
+	int res, ret = RET_PASS, fd, c, shm_id;
+	u_int32_t f_private = 0;
+	pthread_t waiter;
+
+	futex8  f8 = 0;
+	futex16 f16 = 0;
+	futex32 f32 = 0;
+	futex64 f64 = 0;
+	unsigned int flags = 0;
+
+	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(4);
+	ksft_print_msg("%s: Test FUTEX2_SIZES\n", basename(argv[0]));
+
+	info("Calling futex2_wait futex: %p\n", futex);
+	futex = &f8;
+	flags = FUTEX_8;
+	test_single_waiter(flags, &ret);
+
+	futex = &f16;
+	flags = FUTEX_16;
+	test_single_waiter(flags, &ret);
+
+	futex = &f32;
+	flags = FUTEX_32;
+	test_single_waiter(flags, &ret);
+
+	futex = &f64;
+	flags = FUTEX_64;
+	test_single_waiter(flags, &ret);
+
+	ksft_print_cnts();
+	return ret;
+}

tools/testing/selftests/futex/include/futex2test.h

@@ -15,6 +15,7 @@
  *****************************************************************************/
 #include "futextest.h"
 #include <stdio.h>
+#include <stdint.h>
 
 #define NSEC_PER_SEC	1000000000L
 
@@ -65,7 +66,7 @@ int gettime64(clock_t clockid, struct timespec64 *tv)
  * @flags: Operation flags
  * @timo:  Optional timeout for operation
  */
-static inline int futex2_wait(volatile void *uaddr, unsigned long val,
+static inline int futex2_wait(volatile void *uaddr, uint64_t val,
 			      unsigned long flags, struct timespec64 *timo)
 {
 	return syscall(__NR_futex_wait, uaddr, val, flags, timo);