runtime: correctly handle signals received on foreign threads

Fixes #3250.

R=rsc
CC=golang-dev
https://golang.org/cl/10757044

misc/cgo/test/cgo_test.go

@@ -42,5 +42,6 @@ func TestCflags(t *testing.T)              { testCflags(t) }
 func Test5337(t *testing.T)                { test5337(t) }
 func Test5548(t *testing.T)                { test5548(t) }
 func Test5603(t *testing.T)                { test5603(t) }
+func Test3250(t *testing.T)                { test3250(t) }
 
 func BenchmarkCgoCall(b *testing.B) { benchCgoCall(b) }

misc/cgo/test/issue3250.go

@@ -0,0 +1,94 @@
+// 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 !windows
+
+package cgotest
+
+/*
+#include <signal.h>
+#include <pthread.h>
+#include <unistd.h>
+#include <stdlib.h>
+
+static void *thread(void *p) {
+	(void)p;
+	const int M = 100;
+	int i;
+	for (i = 0; i < M; i++) {
+		pthread_kill(pthread_self(), SIGCHLD);
+		usleep(rand() % 20 + 5);
+	}
+	return NULL;
+}
+void testSendSIG() {
+	const int N = 20;
+	int i;
+	pthread_t tid[N];
+	for (i = 0; i < N; i++) {
+		usleep(rand() % 200 + 100);
+		pthread_create(&tid[i], 0, thread, NULL);
+	}
+	for (i = 0; i < N; i++)
+		pthread_join(tid[i], 0);
+}
+*/
+import "C"
+
+import (
+	"os"
+	"os/signal"
+	"syscall"
+	"testing"
+	"time"
+)
+
+func test3250(t *testing.T) {
+	const (
+		thres = 5
+		sig   = syscall.SIGCHLD
+	)
+	type result struct {
+		n   int
+		sig os.Signal
+	}
+	var (
+		sigCh     = make(chan os.Signal, 10)
+		waitStart = make(chan struct{})
+		waitDone  = make(chan result)
+	)
+
+	signal.Notify(sigCh, sig)
+
+	go func() {
+		n := 0
+		alarm := time.After(time.Second * 3)
+		for {
+			select {
+			case <-waitStart:
+				waitStart = nil
+			case v := <-sigCh:
+				n++
+				if v != sig || n > thres {
+					waitDone <- result{n, v}
+					return
+				}
+			case <-alarm:
+				waitDone <- result{n, sig}
+				return
+			}
+		}
+	}()
+
+	waitStart <- struct{}{}
+	C.testSendSIG()
+	r := <-waitDone
+	if r.sig != sig {
+		t.Fatalf("received signal %v, but want %v", r.sig, sig)
+	}
+	t.Logf("got %d signals\n", r.n)
+	if r.n <= thres {
+		t.Fatalf("expected more than %d", thres)
+	}
+}

misc/cgo/test/issue3250w.go

@@ -0,0 +1,11 @@
+// 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 windows
+
+package cgotest
+
+import "testing"
+
+func test3250(t *testing.T) {}

src/pkg/runtime/os_darwin.c

@@ -523,30 +523,6 @@ runtime·setprof(bool on)
 		runtime·sigprocmask(SIG_BLOCK, &sigset_prof, nil);
 }
 
-#pragma dataflag 16 // no pointers
-static int8 badsignal[] = "runtime: signal received on thread not created by Go: ";
-
-// This runs on a foreign stack, without an m or a g.  No stack split.
-#pragma textflag 7
-void
-runtime·badsignal(int32 sig)
-{
-	int32 len;
-
-	if (sig == SIGPROF) {
-		return;  // Ignore SIGPROFs intended for a non-Go thread.
-	}
-	runtime·write(2, badsignal, sizeof badsignal - 1);
-	if (0 <= sig && sig < NSIG) {
-		// Can't call findnull() because it will split stack.
-		for(len = 0; runtime·sigtab[sig].name[len]; len++)
-			;
-		runtime·write(2, runtime·sigtab[sig].name, len);
-	}
-	runtime·write(2, "\n", 1);
-	runtime·exit(1);
-}
-
 void
 runtime·setsig(int32 i, GoSighandler *fn, bool restart)
 {

src/pkg/runtime/os_freebsd.c

@@ -235,30 +235,6 @@ runtime·setprof(bool on)
 	USED(on);
 }
 
-#pragma dataflag 16 // no pointers
-static int8 badsignal[] = "runtime: signal received on thread not created by Go: ";
-
-// This runs on a foreign stack, without an m or a g.  No stack split.
-#pragma textflag 7
-void
-runtime·badsignal(int32 sig)
-{
-	int32 len;
-
-	if (sig == SIGPROF) {
-		return;  // Ignore SIGPROFs intended for a non-Go thread.
-	}
-	runtime·write(2, badsignal, sizeof badsignal - 1);
-	if (0 <= sig && sig < NSIG) {
-		// Can't call findnull() because it will split stack.
-		for(len = 0; runtime·sigtab[sig].name[len]; len++)
-			;
-		runtime·write(2, runtime·sigtab[sig].name, len);
-	}
-	runtime·write(2, "\n", 1);
-	runtime·exit(1);
-}
-
 extern void runtime·sigtramp(void);
 
 typedef struct sigaction {

src/pkg/runtime/os_linux.c

@@ -284,30 +284,6 @@ runtime·setprof(bool on)
 	USED(on);
 }
 
-#pragma dataflag 16  // no pointers
-static int8 badsignal[] = "runtime: signal received on thread not created by Go: ";
-
-// This runs on a foreign stack, without an m or a g.  No stack split.
-#pragma textflag 7
-void
-runtime·badsignal(int32 sig)
-{
-	int32 len;
-
-	if (sig == SIGPROF) {
-		return;  // Ignore SIGPROFs intended for a non-Go thread.
-	}
-	runtime·write(2, badsignal, sizeof badsignal - 1);
-	if (0 <= sig && sig < NSIG) {
-		// Can't call findnull() because it will split stack.
-		for(len = 0; runtime·sigtab[sig].name[len]; len++)
-			;
-		runtime·write(2, runtime·sigtab[sig].name, len);
-	}
-	runtime·write(2, "\n", 1);
-	runtime·exit(1);
-}
-
 #ifdef GOARCH_386
 #define sa_handler k_sa_handler
 #endif

src/pkg/runtime/os_netbsd.c

@@ -275,30 +275,6 @@ runtime·setprof(bool on)
 	USED(on);
 }
 
-#pragma dataflag 16 // no pointers
-static int8 badsignal[] = "runtime: signal received on thread not created by Go: ";
-
-// This runs on a foreign stack, without an m or a g.  No stack split.
-#pragma textflag 7
-void
-runtime·badsignal(int32 sig)
-{
-	int32 len;
-
-	if (sig == SIGPROF) {
-		return;  // Ignore SIGPROFs intended for a non-Go thread.
-	}
-	runtime·write(2, badsignal, sizeof badsignal - 1);
-	if (0 <= sig && sig < NSIG) {
-		// Can't call findnull() because it will split stack.
-		for(len = 0; runtime·sigtab[sig].name[len]; len++)
-			;
-		runtime·write(2, runtime·sigtab[sig].name, len);
-	}
-	runtime·write(2, "\n", 1);
-	runtime·exit(1);
-}
-
 extern void runtime·sigtramp(void);
 
 typedef struct sigaction {

src/pkg/runtime/os_openbsd.c

@@ -257,30 +257,6 @@ runtime·setprof(bool on)
 	USED(on);
 }
 
-#pragma dataflag 16 // no pointers
-static int8 badsignal[] = "runtime: signal received on thread not created by Go: ";
-
-// This runs on a foreign stack, without an m or a g.  No stack split.
-#pragma textflag 7
-void
-runtime·badsignal(int32 sig)
-{
-	int32 len;
-
-	if (sig == SIGPROF) {
-		return;  // Ignore SIGPROFs intended for a non-Go thread.
-	}
-	runtime·write(2, badsignal, sizeof badsignal - 1);
-	if (0 <= sig && sig < NSIG) {
-		// Can't call findnull() because it will split stack.
-		for(len = 0; runtime·sigtab[sig].name[len]; len++)
-			;
-		runtime·write(2, runtime·sigtab[sig].name, len);
-	}
-	runtime·write(2, "\n", 1);
-	runtime·exit(1);
-}
-
 extern void runtime·sigtramp(void);
 
 typedef struct sigaction {

src/pkg/runtime/os_plan9.c

@@ -336,7 +336,7 @@ static int8 badsignal[] = "runtime: signal received on thread not created by Go.
 // This runs on a foreign stack, without an m or a g.  No stack split.
 #pragma textflag 7
 void
-runtime·badsignal(void)
+runtime·badsignal2(void)
 {
 	runtime·pwrite(2, badsignal, sizeof badsignal - 1, -1LL);
 	runtime·exits(badsignal);

src/pkg/runtime/sigqueue.goc

@@ -28,6 +28,7 @@ package runtime
 #include "runtime.h"
 #include "defs_GOOS_GOARCH.h"
 #include "os_GOOS.h"
+#include "cgocall.h"
 
 static struct {
 	Note;
@@ -155,3 +156,11 @@ func signal_disable(s uint32) {
 	sig.wanted[s/32] &= ~(1U<<(s&31));
 	runtime·sigdisable(s);
 }
+
+// This runs on a foreign stack, without an m or a g.  No stack split.
+#pragma textflag 7
+void
+runtime·badsignal(uintptr sig)
+{
+	runtime·cgocallback((void (*)(void))runtime·sigsend, &sig, sizeof(sig));
+}

src/pkg/runtime/sys_darwin_386.s

@@ -238,11 +238,12 @@ TEXT runtime·sigtramp(SB),7,$40
 	// check that m exists
 	MOVL	m(CX), BP
 	CMPL	BP, $0
-	JNE	5(PC)
+	JNE	6(PC)
 	MOVL	sig+8(FP), BX
 	MOVL	BX, 0(SP)
-	CALL	runtime·badsignal(SB)
-	RET
+	MOVL	$runtime·badsignal(SB), AX
+	CALL	AX
+	JMP 	sigtramp_ret
 
 	// save g
 	MOVL	g(CX), DI
@@ -269,6 +270,7 @@ TEXT runtime·sigtramp(SB),7,$40
 	MOVL	20(SP), DI
 	MOVL	DI, g(CX)
 
+sigtramp_ret:
 	// call sigreturn
 	MOVL	context+16(FP), CX
 	MOVL	style+4(FP), BX

src/pkg/runtime/sys_darwin_amd64.s

@@ -192,13 +192,17 @@ TEXT runtime·sigaction(SB),7,$0
 TEXT runtime·sigtramp(SB),7,$64
 	get_tls(BX)
 
+	MOVQ	R8, 32(SP)	// save ucontext
+	MOVQ	SI, 40(SP)	// save infostyle
+
 	// check that m exists
 	MOVQ	m(BX), BP
 	CMPQ	BP, $0
-	JNE	4(PC)
+	JNE	5(PC)
 	MOVL	DX, 0(SP)
-	CALL	runtime·badsignal(SB)
-	RET
+	MOVQ	$runtime·badsignal(SB), AX
+	CALL	AX
+	JMP 	sigtramp_ret
 
 	// save g
 	MOVQ	g(BX), R10
@@ -213,15 +217,14 @@ TEXT runtime·sigtramp(SB),7,$64
 	MOVQ	R8, 16(SP)
 	MOVQ	R10, 24(SP)
 
-	MOVQ	R8, 32(SP)	// save ucontext
-	MOVQ	SI, 40(SP)	// save infostyle
 	CALL	DI
 
 	// restore g
 	get_tls(BX)
 	MOVQ	48(SP), R10
 	MOVQ	R10, g(BX)
 
+sigtramp_ret:
 	// call sigreturn
 	MOVL	$(0x2000000+184), AX	// sigreturn(ucontext, infostyle)
 	MOVQ	32(SP), DI	// saved ucontext

src/pkg/runtime/sys_freebsd_386.s

@@ -183,11 +183,12 @@ TEXT runtime·sigtramp(SB),7,$44
 	// check that m exists
 	MOVL	m(CX), BX
 	CMPL	BX, $0
-	JNE	5(PC)
+	JNE	6(PC)
 	MOVL	signo+0(FP), BX
 	MOVL	BX, 0(SP)
-	CALL	runtime·badsignal(SB)
-	RET
+	MOVL	$runtime·badsignal(SB), AX
+	CALL	AX
+	JMP 	sigtramp_ret
 
 	// save g
 	MOVL	g(CX), DI
@@ -212,7 +213,8 @@ TEXT runtime·sigtramp(SB),7,$44
 	get_tls(CX)
 	MOVL	20(SP), BX
 	MOVL	BX, g(CX)
-
+
+sigtramp_ret:
 	// call sigreturn
 	MOVL	context+8(FP), AX
 	MOVL	$0, 0(SP)	// syscall gap