libthr: test pthread_query_np(3) and pthread_query_all_np(3)

Reviewed by:	markj
Sponsored by:	The FreeBSD Foundation
MFC after:	1 week
Differential revision:	https://reviews.freebsd.org/D60838

lib/libthr/tests/Makefile

@@ -37,6 +37,7 @@ ATF_TESTS_C+=		atfork_test
 ATF_TESTS_C+=		umtx_op_test
 ATF_TESTS_C+=		pthread_sigqueue_test
 ATF_TESTS_C+=		pthread_tryjoin_test
+ATF_TESTS_C+=		pthread_query_test
 
 LIBADD+=		pthread
 LIBADD.fpu_test+=	m

lib/libthr/tests/pthread_query_test.c

@@ -0,0 +1,123 @@
+/*-
+ * SPDX-License-Identifier: BSD-2-Clause
+ *
+ * Copyright 2026 The FreeBSD Foundation
+ *
+ * This software was developed by Konstantin Belousov <kib@FreeBSD.org>
+ * under sponsorship from the FreeBSD Foundation.
+ */
+
+#include <atf-c.h>
+#include <err.h>
+#include <errno.h>
+#include <pthread.h>
+#include <pthread_np.h>
+#include <stdatomic.h>
+#include <stdbool.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <unistd.h>
+
+static atomic_int started;
+
+#define	MY_ERRNO_VAL	0x12345678
+
+static void *
+thr_fun(void *arg)
+{
+	errno = MY_ERRNO_VAL;
+	/* release so the errno update is visible */
+	atomic_store_explicit(&started, 1, memory_order_release);
+	for (;;)
+		sleep(1);
+	return (arg);
+}
+
+ATF_TC(pthread_query_all);
+ATF_TC_HEAD(pthread_query_all, tc)
+{
+	atf_tc_set_md_var(tc, "descr",
+	    "Checks pthread_query_all_np(3)");
+}
+
+ATF_TC_BODY(pthread_query_all, tc)
+{
+	pthread_t thr;
+	struct pthread_info_np *pi;
+	size_t bufsz, n;
+	void *p;
+	int error;
+	bool found;
+
+	error = pthread_create(&thr, NULL, thr_fun, NULL);
+	ATF_REQUIRE_EQ(error, 0);
+
+	while (atomic_load_explicit(&started, memory_order_acquire) != 1)
+		usleep(1000);
+
+	bufsz = 0;
+	error = pthread_query_all_np(NULL, &bufsz);
+	ATF_REQUIRE_EQ(error, ENOMEM);
+	ATF_REQUIRE(bufsz >= sizeof(*pi) * 2);
+	p = malloc(bufsz);
+	ATF_REQUIRE(p != NULL);
+
+	error = pthread_query_all_np((struct pthread_info_np *)p, &bufsz);
+	ATF_REQUIRE_EQ(error, 0);
+
+	found = false;
+	for (n = 0; n < bufsz;) {
+		pi = p;
+		if (pi->thread == thr) {
+			found = true;
+			break;
+		}
+
+		n += pi->pthread_info_size;
+		p = (char *)p + pi->pthread_info_size;
+	}
+
+	ATF_REQUIRE(found);
+	ATF_REQUIRE((pi->flags & PTHREAD_INFO_DETACHED_NP) == 0);
+	ATF_REQUIRE((pi->flags & PTHREAD_INFO_INITIAL_NP) == 0);
+	ATF_REQUIRE_EQ(*(pi->errno_location), MY_ERRNO_VAL);
+}
+
+ATF_TC(pthread_query_main);
+ATF_TC_HEAD(pthread_query_main, tc)
+{
+	atf_tc_set_md_var(tc, "descr",
+	    "Checks pthread_query_np(3) for single initial thread");
+}
+
+ATF_TC_BODY(pthread_query_main, tc)
+{
+	pthread_mutex_t mtx;
+	pthread_t main_thr;
+	struct pthread_info_np pi;
+	int error;
+	static const char main_name[] = "main_name";
+
+	error = pthread_mutex_init(&mtx, NULL);	/* init the threading lib */
+	ATF_REQUIRE_EQ(error, 0);
+
+	main_thr = pthread_self();
+	pthread_set_name_np(main_thr, main_name);
+	error = pthread_query_np(main_thr, &pi, sizeof(pi));
+	ATF_REQUIRE_EQ(error, 0);
+	ATF_REQUIRE_EQ(pi.pthread_info_size, sizeof(pi));
+	ATF_REQUIRE_EQ(pi.state, PTHREAD_STATE_RUNNING_NP);
+	ATF_REQUIRE((pi.flags & PTHREAD_INFO_INITIAL_NP) != 0);
+	ATF_REQUIRE_EQ(pi.thread, main_thr);
+	ATF_REQUIRE_EQ(pi.lwpid, pthread_getthreadid_np());
+	ATF_REQUIRE_EQ(strcmp(pi.name, main_name), 0);
+	ATF_REQUIRE_EQ(pi.errno_location, &errno);
+}
+
+ATF_TP_ADD_TCS(tp)
+{
+	ATF_TP_ADD_TC(tp, pthread_query_main);
+	ATF_TP_ADD_TC(tp, pthread_query_all);
+	return (atf_no_error());
+}