runtime: never show system goroutines in traceback
Fixes #9791
g.issystem flag setup races with other code wherever we set it.
Even if we set both in parent goroutine and in the system goroutine,
it is still possible that some other goroutine crashes
before the flag is set. We could pass issystem flag to newproc1,
but we start all goroutines with go nowadays.
Instead look at g.startpc to distinguish system goroutines (similar to topofstack).
Change-Id: Ia3467968dee27fa07d9fecedd4c2b00928f26645
Reviewed-on: https://go-review.googlesource.com/4113
Reviewed-by: Keith Randall <khr@golang.org>
diff --git a/src/runtime/crash_test.go b/src/runtime/crash_test.go
index 43cea90..715b2da 100644
--- a/src/runtime/crash_test.go
+++ b/src/runtime/crash_test.go
@@ -10,6 +10,7 @@
"os"
"os/exec"
"path/filepath"
+ "regexp"
"runtime"
"strings"
"sync"
@@ -17,17 +18,20 @@
"text/template"
)
-// testEnv excludes GODEBUG from the environment
-// to prevent its output from breaking tests that
-// are trying to parse other command output.
func testEnv(cmd *exec.Cmd) *exec.Cmd {
if cmd.Env != nil {
panic("environment already set")
}
for _, env := range os.Environ() {
+ // Exclude GODEBUG from the environment to prevent its output
+ // from breaking tests that are trying to parse other command output.
if strings.HasPrefix(env, "GODEBUG=") {
continue
}
+ // Exclude GOTRACEBACK for the same reason.
+ if strings.HasPrefix(env, "GOTRACEBACK=") {
+ continue
+ }
cmd.Env = append(cmd.Env, env)
}
return cmd
@@ -217,6 +221,14 @@
}
}
+func TestNoHelperGoroutines(t *testing.T) {
+ output := executeTest(t, noHelperGoroutinesSource, nil)
+ matches := regexp.MustCompile(`goroutine [0-9]+ \[`).FindAllStringSubmatch(output, -1)
+ if len(matches) != 1 || matches[0][0] != "goroutine 1 [" {
+ t.Fatalf("want to see only goroutine 1, see:\n%s", output)
+ }
+}
+
func TestBreakpoint(t *testing.T) {
output := executeTest(t, breakpointSource, nil)
want := "runtime.Breakpoint()"
@@ -431,6 +443,22 @@
}
`
+const noHelperGoroutinesSource = `
+package main
+import (
+ "runtime"
+ "time"
+)
+func init() {
+ i := 0
+ runtime.SetFinalizer(&i, func(p *int) {})
+ time.AfterFunc(time.Hour, func() {})
+ panic("oops")
+}
+func main() {
+}
+`
+
const breakpointSource = `
package main
import "runtime"
diff --git a/src/runtime/heapdump.go b/src/runtime/heapdump.go
index 6cbb5f3..7b4a846 100644
--- a/src/runtime/heapdump.go
+++ b/src/runtime/heapdump.go
@@ -344,7 +344,7 @@
dumpint(uint64(gp.goid))
dumpint(uint64(gp.gopc))
dumpint(uint64(readgstatus(gp)))
- dumpbool(gp.issystem)
+ dumpbool(isSystemGoroutine(gp))
dumpbool(false) // isbackground
dumpint(uint64(gp.waitsince))
dumpstr(gp.waitreason)
diff --git a/src/runtime/mfinal.go b/src/runtime/mfinal.go
index 28afa0d..525aa09 100644
--- a/src/runtime/mfinal.go
+++ b/src/runtime/mfinal.go
@@ -102,7 +102,10 @@
return res
}
-var fingCreate uint32
+var (
+ fingCreate uint32
+ fingRunning bool
+)
func createfing() {
// start the finalizer goroutine exactly once
@@ -126,9 +129,7 @@
gp := getg()
fing = gp
fingwait = true
- gp.issystem = true
goparkunlock(&finlock, "finalizer wait", traceEvGoBlock)
- gp.issystem = false
continue
}
unlock(&finlock)
@@ -169,7 +170,9 @@
default:
throw("bad kind in runfinq")
}
+ fingRunning = true
reflectcall(nil, unsafe.Pointer(f.fn), frame, uint32(framesz), uint32(framesz))
+ fingRunning = false
// drop finalizer queue references to finalized object
f.fn = nil
diff --git a/src/runtime/mgc0.go b/src/runtime/mgc0.go
index bbd786d..f54d933 100644
--- a/src/runtime/mgc0.go
+++ b/src/runtime/mgc0.go
@@ -62,7 +62,6 @@
// bggc holds the state of the backgroundgc.
func backgroundgc() {
bggc.g = getg()
- bggc.g.issystem = true
for {
gcwork(0)
lock(&bggc.lock)
@@ -73,7 +72,6 @@
func bgsweep() {
sweep.g = getg()
- getg().issystem = true
for {
for gosweepone() != ^uintptr(0) {
sweep.nbgsweep++
diff --git a/src/runtime/proc.go b/src/runtime/proc.go
index c8f6de1..0411d96 100644
--- a/src/runtime/proc.go
+++ b/src/runtime/proc.go
@@ -110,7 +110,6 @@
func forcegchelper() {
forcegc.g = getg()
- forcegc.g.issystem = true
for {
lock(&forcegc.lock)
if forcegc.idle != 0 {
diff --git a/src/runtime/proc1.go b/src/runtime/proc1.go
index 70addbf..1f3ae50 100644
--- a/src/runtime/proc1.go
+++ b/src/runtime/proc1.go
@@ -2636,7 +2636,7 @@
lock(&allglock)
for i := 0; i < len(allgs); i++ {
gp := allgs[i]
- if gp.issystem {
+ if isSystemGoroutine(gp) {
continue
}
s := readgstatus(gp)
diff --git a/src/runtime/runtime2.go b/src/runtime/runtime2.go
index e38d11a..fab2ccb 100644
--- a/src/runtime/runtime2.go
+++ b/src/runtime/runtime2.go
@@ -199,7 +199,6 @@
waitsince int64 // approx time when the g become blocked
waitreason string // if status==gwaiting
schedlink *g
- issystem bool // do not output in stack dump, ignore in deadlock detector
preempt bool // preemption signal, duplicates stackguard0 = stackpreempt
paniconfault bool // panic (instead of crash) on unexpected fault address
preemptscan bool // preempted g does scan for gc
diff --git a/src/runtime/time.go b/src/runtime/time.go
index 50895ca..6a2cc21 100644
--- a/src/runtime/time.go
+++ b/src/runtime/time.go
@@ -153,7 +153,6 @@
// If addtimer inserts a new earlier event, addtimer1 wakes timerproc early.
func timerproc() {
timers.gp = getg()
- timers.gp.issystem = true
for {
lock(&timers.lock)
timers.sleeping = false
diff --git a/src/runtime/traceback.go b/src/runtime/traceback.go
index 6c87d7e..8c31c5a 100644
--- a/src/runtime/traceback.go
+++ b/src/runtime/traceback.go
@@ -39,6 +39,11 @@
mstartPC uintptr
rt0_goPC uintptr
sigpanicPC uintptr
+ runfinqPC uintptr
+ backgroundgcPC uintptr
+ bgsweepPC uintptr
+ forcegchelperPC uintptr
+ timerprocPC uintptr
systemstack_switchPC uintptr
externalthreadhandlerp uintptr // initialized elsewhere
@@ -56,6 +61,11 @@
mstartPC = funcPC(mstart)
rt0_goPC = funcPC(rt0_go)
sigpanicPC = funcPC(sigpanic)
+ runfinqPC = funcPC(runfinq)
+ backgroundgcPC = funcPC(backgroundgc)
+ bgsweepPC = funcPC(bgsweep)
+ forcegchelperPC = funcPC(forcegchelper)
+ timerprocPC = funcPC(timerproc)
systemstack_switchPC = funcPC(systemstack_switch)
}
@@ -606,7 +616,7 @@
lock(&allglock)
for _, gp := range allgs {
- if gp == me || gp == g.m.curg || readgstatus(gp) == _Gdead || gp.issystem && level < 2 {
+ if gp == me || gp == g.m.curg || readgstatus(gp) == _Gdead || isSystemGoroutine(gp) && level < 2 {
continue
}
print("\n")
@@ -631,3 +641,14 @@
pc == rt0_goPC ||
externalthreadhandlerp != 0 && pc == externalthreadhandlerp
}
+
+// isSystemGoroutine returns true if the goroutine g must be omitted in
+// stack dumps and deadlock detector.
+func isSystemGoroutine(gp *g) bool {
+ pc := gp.startpc
+ return pc == runfinqPC && !fingRunning ||
+ pc == backgroundgcPC ||
+ pc == bgsweepPC ||
+ pc == forcegchelperPC ||
+ pc == timerprocPC
+}
