runtime: log all thread stack traces during GODEBUG=crash on Unix

This extends https://golang.org/cl/2811, which only applied to Darwin
and GNU/Linux, to all Unix systems.

Fixes #9591.

Change-Id: Iec3fb438564ba2924b15b447c0480f87c0bfd009
Reviewed-on: https://go-review.googlesource.com/12661
Run-TryBot: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Matthew Dempsky <mdempsky@google.com>
Reviewed-by: Russ Cox <rsc@golang.org>

src/runtime/crash_unix_test.go

@@ -0,0 +1,135 @@
+// Copyright 2012 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 darwin dragonfly freebsd linux netbsd openbsd solaris
+
+package runtime_test
+
+import (
+	"bytes"
+	"internal/testenv"
+	"io/ioutil"
+	"os"
+	"os/exec"
+	"path/filepath"
+	"runtime"
+	"syscall"
+	"testing"
+)
+
+func TestCrashDumpsAllThreads(t *testing.T) {
+	switch runtime.GOOS {
+	case "darwin", "dragonfly", "freebsd", "linux", "netbsd", "openbsd", "solaris":
+	default:
+		t.Skipf("skipping; not supported on %v", runtime.GOOS)
+	}
+
+	// We don't use executeTest because we need to kill the
+	// program while it is running.
+
+	testenv.MustHaveGoBuild(t)
+
+	checkStaleRuntime(t)
+
+	dir, err := ioutil.TempDir("", "go-build")
+	if err != nil {
+		t.Fatalf("failed to create temp directory: %v", err)
+	}
+	defer os.RemoveAll(dir)
+
+	if err := ioutil.WriteFile(filepath.Join(dir, "main.go"), []byte(crashDumpsAllThreadsSource), 0666); err != nil {
+		t.Fatalf("failed to create Go file: %v", err)
+	}
+
+	cmd := exec.Command("go", "build", "-o", "a.exe")
+	cmd.Dir = dir
+	out, err := testEnv(cmd).CombinedOutput()
+	if err != nil {
+		t.Fatalf("building source: %v\n%s", err, out)
+	}
+
+	cmd = exec.Command(filepath.Join(dir, "a.exe"))
+	cmd = testEnv(cmd)
+	cmd.Env = append(cmd.Env, "GOTRACEBACK=crash")
+	var outbuf bytes.Buffer
+	cmd.Stdout = &outbuf
+	cmd.Stderr = &outbuf
+
+	rp, wp, err := os.Pipe()
+	if err != nil {
+		t.Fatal(err)
+	}
+	cmd.ExtraFiles = []*os.File{wp}
+
+	if err := cmd.Start(); err != nil {
+		t.Fatalf("starting program: %v", err)
+	}
+
+	if err := wp.Close(); err != nil {
+		t.Logf("closing write pipe: %v", err)
+	}
+	if _, err := rp.Read(make([]byte, 1)); err != nil {
+		t.Fatalf("reading from pipe: %v", err)
+	}
+
+	if err := cmd.Process.Signal(syscall.SIGQUIT); err != nil {
+		t.Fatalf("signal: %v", err)
+	}
+
+	// No point in checking the error return from Wait--we expect
+	// it to fail.
+	cmd.Wait()
+
+	// We want to see a stack trace for each thread.
+	// Before https://golang.org/cl/2811 running threads would say
+	// "goroutine running on other thread; stack unavailable".
+	out = outbuf.Bytes()
+	n := bytes.Count(out, []byte("main.loop("))
+	if n != 4 {
+		t.Errorf("found %d instances of main.loop; expected 4", n)
+		t.Logf("%s", out)
+	}
+}
+
+const crashDumpsAllThreadsSource = `
+package main
+
+import (
+	"fmt"
+	"os"
+	"runtime"
+)
+
+func main() {
+	const count = 4
+	runtime.GOMAXPROCS(count + 1)
+
+	chans := make([]chan bool, count)
+	for i := range chans {
+		chans[i] = make(chan bool)
+		go loop(i, chans[i])
+	}
+
+	// Wait for all the goroutines to start executing.
+	for _, c := range chans {
+		<-c
+	}
+
+	// Tell our parent that all the goroutines are executing.
+	if _, err := os.NewFile(3, "pipe").WriteString("x"); err != nil {
+		fmt.Fprintf(os.Stderr, "write to pipe failed: %v\n", err)
+		os.Exit(2)
+	}
+
+	select {}
+}
+
+func loop(i int, c chan bool) {
+	close(c)
+	for {
+		for j := 0; j < 0x7fffffff; j++ {
+		}
+	}
+}
+`

src/runtime/signal_386.go

@@ -170,9 +170,6 @@ func sighandler(sig uint32, info *siginfo, ctxt unsafe.Pointer, gp *g) {
 	}
 
 	if docrash {
-		// TODO(rsc): Implement raiseproc on other systems
-		// and then add to this if condition.
-		if GOOS == "linux" {
 		crashing++
 		if crashing < sched.mcount {
 			// There are other m's that need to dump their stacks.
@@ -189,7 +186,6 @@ func sighandler(sig uint32, info *siginfo, ctxt unsafe.Pointer, gp *g) {
 			raiseproc(_SIGQUIT)
 			usleep(5 * 1000 * 1000)
 		}
-		}
 		crash()
 	}
 

src/runtime/signal_amd64x.go

@@ -181,9 +181,6 @@ func sighandler(sig uint32, info *siginfo, ctxt unsafe.Pointer, gp *g) {
 	}
 
 	if docrash {
-		// TODO(rsc): Implement raiseproc on other systems
-		// and then add to this if condition.
-		if GOOS == "darwin" || GOOS == "linux" {
 		crashing++
 		if crashing < sched.mcount {
 			// There are other m's that need to dump their stacks.
@@ -200,7 +197,6 @@ func sighandler(sig uint32, info *siginfo, ctxt unsafe.Pointer, gp *g) {
 			raiseproc(_SIGQUIT)
 			usleep(5 * 1000 * 1000)
 		}
-		}
 		crash()
 	}
 

src/runtime/signal_arm.go

@@ -32,6 +32,8 @@ func dumpregs(c *sigctxt) {
 	print("fault   ", hex(c.fault()), "\n")
 }
 
+var crashing int32
+
 // May run during STW, so write barriers are not allowed.
 //go:nowritebarrier
 func sighandler(sig uint32, info *siginfo, ctxt unsafe.Pointer, gp *g) {
@@ -106,7 +108,10 @@ func sighandler(sig uint32, info *siginfo, ctxt unsafe.Pointer, gp *g) {
 
 	_g_.m.throwing = 1
 	_g_.m.caughtsig.set(gp)
+
+	if crashing == 0 {
 		startpanic()
+	}
 
 	if sig < uint32(len(sigtable)) {
 		print(sigtable[sig].name, "\n")
@@ -114,7 +119,7 @@ func sighandler(sig uint32, info *siginfo, ctxt unsafe.Pointer, gp *g) {
 		print("Signal ", sig, "\n")
 	}
 
-	print("PC=", hex(c.pc()), "\n")
+	print("PC=", hex(c.pc()), " m=", _g_.m.id, "\n")
 	if _g_.m.lockedg != nil && _g_.m.ncgo > 0 && gp == _g_.m.g0 {
 		print("signal arrived during cgo execution\n")
 		gp = _g_.m.lockedg
@@ -125,12 +130,34 @@ func sighandler(sig uint32, info *siginfo, ctxt unsafe.Pointer, gp *g) {
 	if gotraceback(&docrash) > 0 {
 		goroutineheader(gp)
 		tracebacktrap(uintptr(c.pc()), uintptr(c.sp()), uintptr(c.lr()), gp)
+		if crashing > 0 && gp != _g_.m.curg && _g_.m.curg != nil && readgstatus(_g_.m.curg)&^_Gscan == _Grunning {
+			// tracebackothers on original m skipped this one; trace it now.
+			goroutineheader(_g_.m.curg)
+			traceback(^uintptr(0), ^uintptr(0), 0, gp)
+		} else if crashing == 0 {
 			tracebackothers(gp)
 			print("\n")
+		}
 		dumpregs(c)
 	}
 
 	if docrash {
+		crashing++
+		if crashing < sched.mcount {
+			// There are other m's that need to dump their stacks.
+			// Relay SIGQUIT to the next m by sending it to the current process.
+			// All m's that have already received SIGQUIT have signal masks blocking
+			// receipt of any signals, so the SIGQUIT will go to an m that hasn't seen it yet.
+			// When the last m receives the SIGQUIT, it will fall through to the call to
+			// crash below. Just in case the relaying gets botched, each m involved in
+			// the relay sleeps for 5 seconds and then does the crash/exit itself.
+			// In expected operation, the last m has received the SIGQUIT and run
+			// crash/exit and the process is gone, all long before any of the
+			// 5-second sleeps have finished.
+			print("\n-----\n\n")
+			raiseproc(_SIGQUIT)
+			usleep(5 * 1000 * 1000)
+		}
 		crash()
 	}
 

src/runtime/signal_arm64.go

@@ -45,6 +45,8 @@ func dumpregs(c *sigctxt) {
 	print("fault   ", hex(c.fault()), "\n")
 }
 
+var crashing int32
+
 // May run during STW, so write barriers are not allowed.
 //go:nowritebarrier
 func sighandler(sig uint32, info *siginfo, ctxt unsafe.Pointer, gp *g) {
@@ -119,7 +121,10 @@ func sighandler(sig uint32, info *siginfo, ctxt unsafe.Pointer, gp *g) {
 
 	_g_.m.throwing = 1
 	_g_.m.caughtsig.set(gp)
+
+	if crashing == 0 {
 		startpanic()
+	}
 
 	if sig < uint32(len(sigtable)) {
 		print(sigtable[sig].name, "\n")
@@ -127,7 +132,7 @@ func sighandler(sig uint32, info *siginfo, ctxt unsafe.Pointer, gp *g) {
 		print("Signal ", sig, "\n")
 	}
 
-	print("PC=", hex(c.pc()), "\n")
+	print("PC=", hex(c.pc()), " m=", _g_.m.id, "\n")
 	if _g_.m.lockedg != nil && _g_.m.ncgo > 0 && gp == _g_.m.g0 {
 		print("signal arrived during cgo execution\n")
 		gp = _g_.m.lockedg
@@ -138,12 +143,34 @@ func sighandler(sig uint32, info *siginfo, ctxt unsafe.Pointer, gp *g) {
 	if gotraceback(&docrash) > 0 {
 		goroutineheader(gp)
 		tracebacktrap(uintptr(c.pc()), uintptr(c.sp()), uintptr(c.lr()), gp)
+		if crashing > 0 && gp != _g_.m.curg && _g_.m.curg != nil && readgstatus(_g_.m.curg)&^_Gscan == _Grunning {
+			// tracebackothers on original m skipped this one; trace it now.
+			goroutineheader(_g_.m.curg)
+			traceback(^uintptr(0), ^uintptr(0), 0, gp)
+		} else if crashing == 0 {
 			tracebackothers(gp)
 			print("\n")
+		}
 		dumpregs(c)
 	}
 
 	if docrash {
+		crashing++
+		if crashing < sched.mcount {
+			// There are other m's that need to dump their stacks.
+			// Relay SIGQUIT to the next m by sending it to the current process.
+			// All m's that have already received SIGQUIT have signal masks blocking
+			// receipt of any signals, so the SIGQUIT will go to an m that hasn't seen it yet.
+			// When the last m receives the SIGQUIT, it will fall through to the call to
+			// crash below. Just in case the relaying gets botched, each m involved in
+			// the relay sleeps for 5 seconds and then does the crash/exit itself.
+			// In expected operation, the last m has received the SIGQUIT and run
+			// crash/exit and the process is gone, all long before any of the
+			// 5-second sleeps have finished.
+			print("\n-----\n\n")
+			raiseproc(_SIGQUIT)
+			usleep(5 * 1000 * 1000)
+		}
 		crash()
 	}
 

src/runtime/signal_ppc64x.go

@@ -50,6 +50,8 @@ func dumpregs(c *sigctxt) {
 	print("trap ", hex(c.trap()), "\n")
 }
 
+var crashing int32
+
 // May run during STW, so write barriers are not allowed.
 //go:nowritebarrier
 func sighandler(sig uint32, info *siginfo, ctxt unsafe.Pointer, gp *g) {
@@ -124,7 +126,10 @@ func sighandler(sig uint32, info *siginfo, ctxt unsafe.Pointer, gp *g) {
 
 	_g_.m.throwing = 1
 	_g_.m.caughtsig.set(gp)
+
+	if crashing == 0 {
 		startpanic()
+	}
 
 	if sig < uint32(len(sigtable)) {
 		print(sigtable[sig].name, "\n")
@@ -132,7 +137,7 @@ func sighandler(sig uint32, info *siginfo, ctxt unsafe.Pointer, gp *g) {
 		print("Signal ", sig, "\n")
 	}
 
-	print("PC=", hex(c.pc()), "\n")
+	print("PC=", hex(c.pc()), " m=", _g_.m.id, "\n")
 	if _g_.m.lockedg != nil && _g_.m.ncgo > 0 && gp == _g_.m.g0 {
 		print("signal arrived during cgo execution\n")
 		gp = _g_.m.lockedg
@@ -143,12 +148,34 @@ func sighandler(sig uint32, info *siginfo, ctxt unsafe.Pointer, gp *g) {
 	if gotraceback(&docrash) > 0 {
 		goroutineheader(gp)
 		tracebacktrap(uintptr(c.pc()), uintptr(c.sp()), uintptr(c.link()), gp)
+		if crashing > 0 && gp != _g_.m.curg && _g_.m.curg != nil && readgstatus(_g_.m.curg)&^_Gscan == _Grunning {
+			// tracebackothers on original m skipped this one; trace it now.
+			goroutineheader(_g_.m.curg)
+			traceback(^uintptr(0), ^uintptr(0), 0, gp)
+		} else if crashing == 0 {
 			tracebackothers(gp)
 			print("\n")
+		}
 		dumpregs(c)
 	}
 
 	if docrash {
+		crashing++
+		if crashing < sched.mcount {
+			// There are other m's that need to dump their stacks.
+			// Relay SIGQUIT to the next m by sending it to the current process.
+			// All m's that have already received SIGQUIT have signal masks blocking
+			// receipt of any signals, so the SIGQUIT will go to an m that hasn't seen it yet.
+			// When the last m receives the SIGQUIT, it will fall through to the call to
+			// crash below. Just in case the relaying gets botched, each m involved in
+			// the relay sleeps for 5 seconds and then does the crash/exit itself.
+			// In expected operation, the last m has received the SIGQUIT and run
+			// crash/exit and the process is gone, all long before any of the
+			// 5-second sleeps have finished.
+			print("\n-----\n\n")
+			raiseproc(_SIGQUIT)
+			usleep(5 * 1000 * 1000)
+		}
 		crash()
 	}
 

src/runtime/sys_darwin_arm.s

@@ -97,7 +97,12 @@ TEXT runtime·exit1(SB),NOSPLIT,$0
 	MOVW	$1003, R1
 	MOVW	R0, (R1)	// fail hard
 
-TEXT runtime·raise(SB),NOSPLIT,$24
+TEXT runtime·raise(SB),NOSPLIT,$0
+	// Ideally we'd send the signal to the current thread,
+	// not the whole process, but that's too hard on OS X.
+	JMP	runtime·raiseproc(SB)
+
+TEXT runtime·raiseproc(SB),NOSPLIT,$24
 	MOVW	$SYS_getpid, R12
 	SWI	$0x80
 	// arg 1 pid already in R0 from getpid

src/runtime/sys_darwin_arm64.s

@@ -98,6 +98,11 @@ TEXT runtime·exit1(SB),NOSPLIT,$0
 	MOVD	R0, (R1)	// fail hard
 
 TEXT runtime·raise(SB),NOSPLIT,$0
+	// Ideally we'd send the signal to the current thread,
+	// not the whole process, but that's too hard on OS X.
+	JMP	runtime·raiseproc(SB)
+
+TEXT runtime·raiseproc(SB),NOSPLIT,$0
 	MOVW	$SYS_getpid, R16
 	SVC	$0x80
 	// arg 1 pid already in R0 from getpid

src/runtime/sys_dragonfly_amd64.s

@@ -131,6 +131,15 @@ TEXT runtime·raise(SB),NOSPLIT,$16
 	SYSCALL
 	RET
 
+TEXT runtime·raiseproc(SB),NOSPLIT,$0
+	MOVL	$20, AX		// getpid
+	SYSCALL
+	MOVQ	AX, DI		// arg 1 - pid
+	MOVL	sig+0(FP), SI	// arg 2 - signum
+	MOVL	$37, AX		// kill
+	SYSCALL
+	RET
+
 TEXT runtime·setitimer(SB), NOSPLIT, $-8
 	MOVL	mode+0(FP), DI
 	MOVQ	new+8(FP), SI

src/runtime/sys_freebsd_386.s

@@ -112,6 +112,18 @@ TEXT runtime·raise(SB),NOSPLIT,$16
 	INT	$0x80
 	RET
 
+TEXT runtime·raiseproc(SB),NOSPLIT,$16
+	// getpid
+	MOVL	$20, AX
+	INT	$0x80
+	// kill(self, sig)
+	MOVL	AX, 4(SP)
+	MOVL	sig+0(FP), AX
+	MOVL	AX, 8(SP)
+	MOVL	$37, AX
+	INT	$0x80
+	RET
+
 TEXT runtime·mmap(SB),NOSPLIT,$32
 	LEAL addr+0(FP), SI
 	LEAL	4(SP), DI

src/runtime/sys_freebsd_amd64.s

@@ -123,6 +123,17 @@ TEXT runtime·raise(SB),NOSPLIT,$16
 	SYSCALL
 	RET
 
+TEXT runtime·raiseproc(SB),NOSPLIT,$0
+	// getpid
+	MOVL	$20, AX
+	SYSCALL
+	// kill(self, sig)
+	MOVQ	AX, DI		// arg 1 pid
+	MOVL	sig+0(FP), SI	// arg 2 sig
+	MOVL	$37, AX
+	SYSCALL
+	RET
+
 TEXT runtime·setitimer(SB), NOSPLIT, $-8
 	MOVL	mode+0(FP), DI
 	MOVQ	new+8(FP), SI

src/runtime/sys_freebsd_arm.s

@@ -18,6 +18,8 @@
 #define SYS_write (SYS_BASE + 4)
 #define SYS_open (SYS_BASE + 5)
 #define SYS_close (SYS_BASE + 6)
+#define SYS_getpid (SYS_BASE + 20)
+#define SYS_kill (SYS_BASE + 37)
 #define SYS_sigaltstack (SYS_BASE + 53)
 #define SYS_munmap (SYS_BASE + 73)
 #define SYS_madvise (SYS_BASE + 75)
@@ -145,6 +147,17 @@ TEXT runtime·raise(SB),NOSPLIT,$8
 	SWI $0
 	RET
 
+TEXT runtime·raiseproc(SB),NOSPLIT,$0
+	// getpid
+	MOVW $SYS_getpid, R7
+	SWI $0
+	// kill(self, sig)
+				// arg 1 - pid, now in R0
+	MOVW sig+0(FP), R1	// arg 2 - signal
+	MOVW $SYS_kill, R7
+	SWI $0
+	RET
+
 TEXT runtime·setitimer(SB), NOSPLIT, $-8
 	MOVW mode+0(FP), R0
 	MOVW new+4(FP), R1

src/runtime/sys_linux_arm64.s

@@ -32,7 +32,9 @@
 #define SYS_getrlimit		163
 #define SYS_madvise		233
 #define SYS_mincore		232
+#define SYS_getpid		172
 #define SYS_gettid		178
+#define SYS_kill		129
 #define SYS_tkill		130
 #define SYS_futex		98
 #define SYS_sched_getaffinity	123
@@ -151,6 +153,15 @@ TEXT runtime·raise(SB),NOSPLIT,$-8
 	SVC
 	RET
 
+TEXT runtime·raiseproc(SB),NOSPLIT,$-8
+	MOVD	$SYS_getpid, R8
+	SVC
+	MOVW	R0, R0		// arg 1 pid
+	MOVW	sig+0(FP), R1	// arg 2
+	MOVD	$SYS_kill, R8
+	SVC
+	RET
+
 TEXT runtime·setitimer(SB),NOSPLIT,$-8-24
 	MOVW	mode+0(FP), R0
 	MOVD	new+8(FP), R1

src/runtime/sys_netbsd_386.s

@@ -86,6 +86,17 @@ TEXT runtime·raise(SB),NOSPLIT,$12
 	INT	$0x80
 	RET
 
+TEXT runtime·raiseproc(SB),NOSPLIT,$12
+	MOVL	$20, AX			// sys_getpid
+	INT	$0x80
+	MOVL	$0, 0(SP)
+	MOVL	AX, 4(SP)		// arg 1 - pid
+	MOVL	sig+0(FP), AX
+	MOVL	AX, 8(SP)		// arg 2 - signo
+	MOVL	$37, AX			// sys_kill
+	INT	$0x80
+	RET
+
 TEXT runtime·mmap(SB),NOSPLIT,$36
 	LEAL	addr+0(FP), SI
 	LEAL	4(SP), DI

src/runtime/sys_netbsd_amd64.s

@@ -152,6 +152,15 @@ TEXT runtime·raise(SB),NOSPLIT,$16
 	SYSCALL
 	RET
 
+TEXT runtime·raiseproc(SB),NOSPLIT,$16
+	MOVL	$20, AX			// sys_getpid
+	SYSCALL
+	MOVQ	AX, DI			// arg 1 - pid
+	MOVL	sig+0(FP), SI		// arg 2 - signo
+	MOVL	$37, AX			// sys_kill
+	SYSCALL
+	RET
+
 TEXT runtime·setitimer(SB),NOSPLIT,$-8
 	MOVL	mode+0(FP), DI		// arg 1 - which
 	MOVQ	new+8(FP), SI		// arg 2 - itv

src/runtime/sys_netbsd_arm.s

@@ -127,6 +127,12 @@ TEXT runtime·raise(SB),NOSPLIT,$16
 	SWI $0xa0013e	// sys__lwp_kill
 	RET
 
+TEXT runtime·raiseproc(SB),NOSPLIT,$16
+	SWI $0xa00014	// sys_getpid, the returned R0 is arg 1
+	MOVW	sig+0(FP), R1	// arg 2 - signal
+	SWI $0xa00025	// sys_kill
+	RET
+
 TEXT runtime·setitimer(SB),NOSPLIT,$-4
 	MOVW mode+0(FP), R0	// arg 1 - which
 	MOVW new+4(FP), R1	// arg 2 - itv

src/runtime/sys_openbsd_386.s

@@ -90,6 +90,17 @@ TEXT runtime·raise(SB),NOSPLIT,$12
 	INT	$0x80
 	RET
 
+TEXT runtime·raiseproc(SB),NOSPLIT,$12
+	MOVL	$20, AX			// sys_getpid
+	INT	$0x80
+	MOVL	$0, 0(SP)
+	MOVL	AX, 4(SP)		// arg 1 - pid
+	MOVL	sig+0(FP), AX
+	MOVL	AX, 8(SP)		// arg 2 - signum
+	MOVL	$37, AX			// sys_kill
+	INT	$0x80
+	RET
+
 TEXT runtime·mmap(SB),NOSPLIT,$36
 	LEAL	addr+0(FP), SI
 	LEAL	4(SP), DI

src/runtime/sys_openbsd_amd64.s

@@ -162,6 +162,15 @@ TEXT runtime·raise(SB),NOSPLIT,$16
 	SYSCALL
 	RET
 
+TEXT runtime·raiseproc(SB),NOSPLIT,$16
+	MOVL	$20, AX			// sys_getpid
+	SYSCALL
+	MOVQ	AX, DI			// arg 1 - pid
+	MOVL	sig+0(FP), SI		// arg 2 - signum
+	MOVL	$37, AX			// sys_kill
+	SYSCALL
+	RET
+
 TEXT runtime·setitimer(SB),NOSPLIT,$-8
 	MOVL	mode+0(FP), DI		// arg 1 - which
 	MOVQ	new+8(FP), SI		// arg 2 - itv

src/runtime/sys_openbsd_arm.s

@@ -96,6 +96,15 @@ TEXT runtime·raise(SB),NOSPLIT,$12
 	SWI	$0
 	RET
 
+TEXT runtime·raiseproc(SB),NOSPLIT,$12
+	MOVW	$20, R12
+	SWI	$0			// sys_getpid
+					// arg 1 - pid, already in R0
+	MOVW	sig+0(FP), R1		// arg 2 - signum
+	MOVW	$37, R12		// sys_kill
+	SWI	$0
+	RET
+
 TEXT runtime·mmap(SB),NOSPLIT,$16
 	MOVW	addr+0(FP), R0		// arg 1 - addr
 	MOVW	len+4(FP), R1		// arg 2 - len