From: visa <visa@openbsd.org>
Date: Sun, 26 Aug 2018 06:50:30 +0000 (+0000)
Subject: Add test cases for private versus non-private futexes.
X-Git-Url: http://artulab.com/gitweb/?a=commitdiff_plain;h=116b6a5ef01f5b8841eb46b536173785ac7e4670;p=openbsd

Add test cases for private versus non-private futexes.

While here, fix timeout handling in futex_twait(), and fix the return
value of functions awakener() and signaled().

OK mpi@
---

diff --git a/regress/sys/kern/futex/futex.c b/regress/sys/kern/futex/futex.c
index f60f9362067..61816f2e888 100644
--- a/regress/sys/kern/futex/futex.c
+++ b/regress/sys/kern/futex/futex.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: futex.c,v 1.2 2017/04/30 10:11:03 mpi Exp $ */
+/*	$OpenBSD: futex.c,v 1.3 2018/08/26 06:50:30 visa Exp $ */
 /*
  * Copyright (c) 2017 Martin Pieuchot
  *
@@ -17,17 +17,21 @@
 
 #include <sys/time.h>
 #include <sys/futex.h>
+#include <sys/mman.h>
+#include <sys/wait.h>
 
 #include <assert.h>
 #include <errno.h>
 #include <pthread.h>
 #include <signal.h>
+#include <stdlib.h>
 #include <string.h>
 #include <unistd.h>
 
 #include "futex.h"
 
 uint32_t lock = 0;
+uint32_t *shlock;
 
 void handler(int);
 void *signaled(void *);
@@ -36,21 +40,24 @@ void *awakener(void *);
 int
 main(int argc, char *argv[])
 {
+	char filename[] = "/tmp/futex.XXXXXXXX";
 	struct sigaction sa;
-	struct timespec abs = { 0, 5000 };
+	struct timespec tmo = { 0, 5000 };
 	pthread_t thread;
+	pid_t pid;
+	int fd, i, status;
 
 	/* Invalid operation */
 	assert(futex(&lock, 0xFFFF, 0, 0, NULL) == ENOSYS);
 
 	/* Incorrect pointer */
-	assert(futex_twait((void *)0xdeadbeef, 1, 0, NULL) == EFAULT);
+	assert(futex_twait((void *)0xdeadbeef, 1, 0, NULL, 0) == EFAULT);
 
 	/* If (lock != 1) return EAGAIN */
-	assert(futex_twait(&lock, 1, 0, NULL) == EAGAIN);
+	assert(futex_twait(&lock, 1, 0, NULL, 0) == EAGAIN);
 
 	/* Deadlock for 5000ns */
-	assert(futex_twait(&lock, 0, CLOCK_REALTIME, &abs) == ETIMEDOUT);
+	assert(futex_twait(&lock, 0, CLOCK_REALTIME, &tmo, 0) == ETIMEDOUT);
 
 	/* Interrupt a thread waiting on a futex. */
 	memset(&sa, 0, sizeof(sa));
@@ -63,9 +70,55 @@ main(int argc, char *argv[])
 
 	/* Wait until another thread awakes us. */
 	assert(pthread_create(&thread, NULL, awakener, NULL) == 0);
-	assert(futex_twait(&lock, 0, 0, NULL) == 0);
+	assert(futex_twait(&lock, 0, 0, NULL, 0) == 0);
 	assert(pthread_join(thread, NULL) == 0);
 
+	/* Create a uvm object for sharing a lock. */
+	fd = mkstemp(filename);
+	assert(fd != -1);
+	unlink(filename);
+	assert(ftruncate(fd, 65536) == 0);
+	shlock = mmap(NULL, sizeof(*shlock), PROT_READ | PROT_WRITE,
+	    MAP_SHARED, fd, 0);
+	assert(shlock != MAP_FAILED);
+	close(fd);
+
+	/* Wake another process. */
+	pid = fork();
+	assert(pid != -1);
+	if (pid == 0) {
+		usleep(50000);
+		futex_wake(shlock, -1, 0);
+		_exit(0);
+	} else {
+		assert(futex_twait(shlock, 0, 0, NULL, 0) == 0);
+		assert(waitpid(pid, &status, 0) == pid);
+		assert(WIFEXITED(status));
+		assert(WEXITSTATUS(status) == 0);
+	}
+
+	/* Cannot wake another process using a private futex. */
+	for (i = 1; i < 4; i++) {
+		pid = fork();
+		assert(pid != -1);
+		if (pid == 0) {
+			usleep(50000);
+			futex_wake(shlock, -1,
+			    (i & 1) ? FUTEX_PRIVATE_FLAG : 0);
+			_exit(0);
+		} else {
+			tmo.tv_sec = 0;
+			tmo.tv_nsec = 200000000;
+			assert(futex_twait(shlock, 0, CLOCK_REALTIME, &tmo,
+			    (i & 2) ? FUTEX_PRIVATE_FLAG : 0) == ETIMEDOUT);
+			assert(waitpid(pid, &status, 0) == pid);
+			assert(WIFEXITED(status));
+			assert(WEXITSTATUS(status) == 0);
+		}
+	}
+
+	assert(munmap(shlock, sizeof(*shlock)) == 0);
+
 	return 0;
 }
 
@@ -78,12 +131,14 @@ void *
 signaled(void *arg)
 {
 	/* Wait until receiving a signal. */
-	assert(futex_twait(&lock, 0, 0, NULL) == EINTR);
+	assert(futex_twait(&lock, 0, 0, NULL, 0) == EINTR);
+	return NULL;
 }
 
 void *
 awakener(void *arg)
 {
 	usleep(100);
-	assert(futex_wake(&lock, -1) == 1);
+	assert(futex_wake(&lock, -1, 0) == 1);
+	return NULL;
 }
diff --git a/regress/sys/kern/futex/futex.h b/regress/sys/kern/futex/futex.h
index c2b382f04f0..828985c72cc 100644
--- a/regress/sys/kern/futex/futex.h
+++ b/regress/sys/kern/futex/futex.h
@@ -1,4 +1,4 @@
-/*	$OpenBSD: futex.h,v 1.1 2017/04/30 09:03:58 mpi Exp $ */
+/*	$OpenBSD: futex.h,v 1.2 2018/08/26 06:50:30 visa Exp $ */
 /*
  * Copyright (c) 2017 Martin Pieuchot
  *
@@ -16,39 +16,23 @@
  */
 
 static inline int
-futex_wake(volatile uint32_t *p, int n)
+futex_wake(volatile uint32_t *p, int n, int priv)
 {
-	return futex(p, FUTEX_WAKE, n, NULL, NULL);
+	return futex(p, FUTEX_WAKE | priv, n, NULL, NULL);
 }
 
 static inline void
-futex_wait(volatile uint32_t *p, int val)
+futex_wait(volatile uint32_t *p, int val, int priv)
 {
 	while (*p != (uint32_t)val)
-		futex(p, FUTEX_WAIT, val, NULL, NULL);
+		futex(p, FUTEX_WAIT | priv, val, NULL, NULL);
 }
 
 static inline int
 futex_twait(volatile uint32_t *p, int val, clockid_t clockid,
-    const struct timespec *abs)
+    const struct timespec *timeout, int priv)
 {
-	struct timespec rel;
-
-	if (abs == NULL)
-		return futex(p, FUTEX_WAIT, val, NULL, NULL);
-
-	if (abs->tv_nsec >= 1000000000 || clock_gettime(clockid, &rel))
-		return (EINVAL);
-
-	rel.tv_sec = abs->tv_sec - rel.tv_sec;
-	if ((rel.tv_nsec = abs->tv_nsec - rel.tv_nsec) < 0) {
-		rel.tv_sec--;
-		rel.tv_nsec += 1000000000;
-	}
-	if (rel.tv_sec < 0)
-		return (ETIMEDOUT);
-
-	return futex(p, FUTEX_WAIT, val, &rel, NULL);
+	return futex(p, FUTEX_WAIT | priv, val, timeout, NULL);
 }
 
 static inline int