use exitgroup on linux to exit whole process.

R=r
DELTA=60  (38 added, 19 deleted, 3 changed)
OCL=28589
CL=28589

src/lib/os/Makefile

@@ -3,7 +3,7 @@
 # license that can be found in the LICENSE file.
 
 # DO NOT EDIT.  Automatically generated by gobuild.
-# gobuild -m dir_${GOARCH}_${GOOS}.go env.go error.go file.go proc.go stat_${GOARCH}_${GOOS}.go time.go types.go exec.go >Makefile
+# gobuild -m dir_${GOARCH}_${GOOS}.go env.go error.go file.go proc_${GOOS}.go stat_${GOARCH}_${GOOS}.go time.go types.go exec.go >Makefile
 
 D=
 
@@ -41,7 +41,7 @@ coverage: packages
 
 O1=\
 	error.$O\
-	proc.$O\
+	proc_$(GOOS).$O\
 	types.$O\
 
 O2=\
@@ -61,7 +61,7 @@ phases: a1 a2 a3 a4
 _obj$D/os.a: phases
 
 a1: $(O1)
-	$(AR) grc _obj$D/os.a error.$O proc.$O types.$O
+	$(AR) grc _obj$D/os.a error.$O proc_$(GOOS).$O types.$O
 	rm -f $(O1)
 
 a2: $(O2)

src/lib/os/proc_linux.go

+// Copyright 2009 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.
+
+package os
+
+import (
+	"os";
+	"syscall";
+)
+
+var Args []string;	// provided by runtime
+var Envs []string;	// provided by runtime
+
+// Exit causes the current program to exit with the given status code.
+// Conventionally, code zero indicates success, non-zero an error.
+func Exit(code int) {
+	syscall.Syscall(syscall.SYS_EXIT_GROUP, int64(code), 0, 0)
+}
+