runtime: fix tv_sec 32-bit overflows in sleep routines.

Fixes #5063.

R=golang-dev, minux.ma, rsc
CC=golang-dev
https://golang.org/cl/7876043

src/pkg/runtime/export_futex_test.go

@@ -0,0 +1,13 @@
+// Copyright 2013 The Go Authors.  All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+// +build linux freebsd
+
+package runtime
+
+func futexsleep(addr *uint32, val uint32, ns int64)
+func futexwakeup(addr *uint32, val uint32)
+
+var Futexsleep = futexsleep
+var Futexwakeup = futexwakeup

src/pkg/runtime/futex_test.go

@@ -0,0 +1,31 @@
+// Copyright 2013 The Go Authors.  All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+// +build linux freebsd
+
+package runtime_test
+
+import (
+	. "runtime"
+	"testing"
+	"time"
+)
+
+func TestFutexsleep(t *testing.T) {
+	ch := make(chan bool, 1)
+	var dummy uint32
+	start := time.Now()
+	go func() {
+		Entersyscall()
+		Futexsleep(&dummy, 0, (1<<31+100)*1e9)
+		Exitsyscall()
+		ch <- true
+	}()
+	select {
+	case <-ch:
+		t.Errorf("futexsleep finished early after %s!", time.Since(start))
+	case <-time.After(time.Second):
+		Futexwakeup(&dummy, 1)
+	}
+}

src/pkg/runtime/os_darwin.c

@@ -409,9 +409,14 @@ int32
 runtime·mach_semacquire(uint32 sem, int64 ns)
 {
 	int32 r;
+	int64 secs;
 
 	if(ns >= 0) {
-		r = runtime·mach_semaphore_timedwait(sem, ns/1000000000LL, ns%1000000000LL);
+		secs = ns/1000000000LL;
+		// Avoid overflow
+		if(secs > 1LL<<30)
+			secs = 1LL<<30;
+		r = runtime·mach_semaphore_timedwait(sem, secs, ns%1000000000LL);
 		if(r == KERN_ABORTED || r == KERN_OPERATION_TIMED_OUT)
 			return -1;
 		if(r != 0)

src/pkg/runtime/os_freebsd.c

@@ -45,11 +45,16 @@ runtime·futexsleep(uint32 *addr, uint32 val, int64 ns)
 {
 	int32 ret;
 	Timespec ts, *tsp;
+	int64 secs;
 
 	if(ns < 0)
 		tsp = nil;
 	else {
-		ts.tv_sec = ns / 1000000000LL;
+		secs = ns / 1000000000LL;
+		// Avoid overflow
+		if(secs > 1LL<<30)
+			secs = 1LL<<30;
+		ts.tv_sec = secs;
 		ts.tv_nsec = ns % 1000000000LL;
 		tsp = &ts;
 	}

src/pkg/runtime/os_linux.c

@@ -36,15 +36,17 @@ void
 runtime·futexsleep(uint32 *addr, uint32 val, int64 ns)
 {
 	Timespec ts, *tsp;
+	int64 secs;
 
 	if(ns < 0)
 		tsp = nil;
 	else {
-		ts.tv_sec = ns/1000000000LL;
-		ts.tv_nsec = ns%1000000000LL;
+		secs = ns/1000000000LL;
 		// Avoid overflow
-		if(ts.tv_sec > 1<<30)
-			ts.tv_sec = 1<<30;
+		if(secs > 1LL<<30)
+			secs = 1LL<<30;
+		ts.tv_sec = secs;
+		ts.tv_nsec = ns%1000000000LL;
 		tsp = &ts;
 	}
 

src/pkg/runtime/os_netbsd.c

@@ -65,6 +65,7 @@ int32
 runtime·semasleep(int64 ns)
 {
 	Timespec ts;
+	int64 secs;
 
 	// spin-mutex lock
 	while(runtime·xchg(&m->waitsemalock, 1))
@@ -93,7 +94,11 @@ runtime·semasleep(int64 ns)
 				runtime·lwp_park(nil, 0, &m->waitsemacount, nil);
 			} else {
 				ns += runtime·nanotime();
-				ts.tv_sec = ns/1000000000LL;
+				secs = ns/1000000000LL;
+				// Avoid overflow
+				if(secs > 1LL<<30)
+					secs = 1LL<<30;
+				ts.tv_sec = secs;
 				ts.tv_nsec = ns%1000000000LL;
 				// TODO(jsing) - potential deadlock!
 				// See above for details.

src/pkg/runtime/os_openbsd.c

@@ -62,6 +62,7 @@ int32
 runtime·semasleep(int64 ns)
 {
 	Timespec ts;
+	int64 secs;
 
 	// spin-mutex lock
 	while(runtime·xchg(&m->waitsemalock, 1))
@@ -76,7 +77,11 @@ runtime·semasleep(int64 ns)
 				runtime·thrsleep(&m->waitsemacount, 0, nil, &m->waitsemalock, nil);
 			else {
 				ns += runtime·nanotime();
-				ts.tv_sec = ns/1000000000LL;
+				secs = ns/1000000000LL;
+				// Avoid overflow
+				if(secs > 1LL<<30)
+					secs = 1LL<<30;
+				ts.tv_sec = secs;
 				ts.tv_nsec = ns%1000000000LL;
 				runtime·thrsleep(&m->waitsemacount, CLOCK_REALTIME, &ts, &m->waitsemalock, nil);
 			}