runtime: ignore arguments in cgocallback_gofunc frame
Otherwise the GC may see uninitialized memory there,
which might be old pointers that are retained, or it might
trigger the invalid pointer check.
Fixes #11907.
Change-Id: I67e306384a68468eef45da1a8eb5c9df216a77c0
Reviewed-on: https://go-review.googlesource.com/12852
Reviewed-by: Ian Lance Taylor <iant@golang.org>
Reviewed-by: Austin Clements <austin@google.com>
diff --git a/src/runtime/crash_cgo_test.go b/src/runtime/crash_cgo_test.go
index d2847b0..d132234 100644
--- a/src/runtime/crash_cgo_test.go
+++ b/src/runtime/crash_cgo_test.go
@@ -36,6 +36,17 @@
}
}
+func TestCgoCallbackGC(t *testing.T) {
+ if runtime.GOOS == "plan9" || runtime.GOOS == "windows" {
+ t.Skipf("no pthreads on %s", runtime.GOOS)
+ }
+ got := executeTest(t, cgoCallbackGCSource, nil)
+ want := "OK\n"
+ if got != want {
+ t.Fatalf("expected %q, but got %q", want, got)
+ }
+}
+
func TestCgoExternalThreadPanic(t *testing.T) {
if runtime.GOOS == "plan9" {
t.Skipf("no pthreads on %s", runtime.GOOS)
@@ -191,6 +202,83 @@
}
`
+const cgoCallbackGCSource = `
+package main
+
+import "runtime"
+
+/*
+#include <pthread.h>
+
+void go_callback();
+
+static void *thr(void *arg) {
+ go_callback();
+ return 0;
+}
+
+static void foo() {
+ pthread_t th;
+ pthread_create(&th, 0, thr, 0);
+ pthread_join(th, 0);
+}
+*/
+import "C"
+import "fmt"
+
+//export go_callback
+func go_callback() {
+ runtime.GC()
+ grow()
+ runtime.GC()
+}
+
+var cnt int
+
+func grow() {
+ x := 10000
+ sum := 0
+ if grow1(&x, &sum) == 0 {
+ panic("bad")
+ }
+}
+
+func grow1(x, sum *int) int {
+ if *x == 0 {
+ return *sum + 1
+ }
+ *x--
+ sum1 := *sum + *x
+ return grow1(x, &sum1)
+}
+
+func main() {
+ const P = 100
+ done := make(chan bool)
+ // allocate a bunch of stack frames and spray them with pointers
+ for i := 0; i < P; i++ {
+ go func() {
+ grow()
+ done <- true
+ }()
+ }
+ for i := 0; i < P; i++ {
+ <-done
+ }
+ // now give these stack frames to cgo callbacks
+ for i := 0; i < P; i++ {
+ go func() {
+ C.foo()
+ done <- true
+ }()
+ }
+ for i := 0; i < P; i++ {
+ <-done
+ }
+ fmt.Printf("OK\n")
+}
+`
+
const cgoExternalThreadPanicSource = `
package main
diff --git a/src/runtime/stubs.go b/src/runtime/stubs.go
index 5ac1c57..e6b0156 100644
--- a/src/runtime/stubs.go
+++ b/src/runtime/stubs.go
@@ -128,9 +128,16 @@
func reflectcall(argtype *_type, fn, arg unsafe.Pointer, argsize uint32, retoffset uint32)
func procyield(cycles uint32)
-func cgocallback_gofunc(fv *funcval, frame unsafe.Pointer, framesize uintptr)
func goexit()
+// Not all cgocallback_gofunc frames are actually cgocallback_gofunc,
+// so not all have these arguments. Mark them uintptr so that the GC
+// does not misinterpret memory when the arguments are not present.
+// cgocallback_gofunc is not called from go, only from cgocallback,
+// so the arguments will be found via cgocallback's pointer-declared arguments.
+// See the assembly implementations for more details.
+func cgocallback_gofunc(fv uintptr, frame uintptr, framesize uintptr)
+
//go:noescape
func cas(ptr *uint32, old, new uint32) bool
