os.FindProcess, process.Release

.github/workflows/linux.yml

@@ -24,7 +24,7 @@ jobs:
         # tar: needed for actions/cache@v4
         # git+openssh: needed for checkout (I think?)
         # ruby: needed to install fpm
-        run: apk add tar git openssh make g++ ruby
+        run: apk add tar git openssh make g++ ruby-dev
       - name: Work around CVE-2022-24765
         # We're not on a multi-user machine, so this is safe.
         run: git config --global --add safe.directory "$GITHUB_WORKSPACE"

src/os/exec.go

@@ -58,10 +58,13 @@ type Process struct {
 }
 
 func StartProcess(name string, argv []string, attr *ProcAttr) (*Process, error) {
-	return nil, &PathError{"fork/exec", name, ErrNotImplemented}
+	return nil, &PathError{Op: "fork/exec", Path: name, Err: ErrNotImplemented}
 }
 
 func (p *Process) Wait() (*ProcessState, error) {
+	if p.Pid == -1 {
+		return nil, syscall.EINVAL
+	}
 	return nil, ErrNotImplemented
 }
 
@@ -72,3 +75,15 @@ func (p *Process) Kill() error {
 func (p *Process) Signal(sig Signal) error {
 	return ErrNotImplemented
 }
+
+// Release releases any resources associated with the Process p,
+// rendering it unusable in the future.
+// Release only needs to be called if Wait is not.
+func (p *Process) Release() error {
+	return p.release()
+}
+
+// Keep compatibility with golang and always succeed and return new proc with pid on Linux.
+func FindProcess(pid int) (*Process, error) {
+	return findProcess(pid)
+}

src/os/exec_posix.go

@@ -7,6 +7,7 @@
 package os
 
 import (
+	"runtime"
 	"syscall"
 )
 
@@ -19,3 +20,16 @@ var (
 	Interrupt Signal = syscall.SIGINT
 	Kill      Signal = syscall.SIGKILL
 )
+
+// Keep compatible with golang and always succeed and return new proc with pid on Linux.
+func findProcess(pid int) (*Process, error) {
+	return &Process{Pid: pid}, nil
+}
+
+func (p *Process) release() error {
+	// NOOP for unix.
+	p.Pid = -1
+	// no need for a finalizer anymore
+	runtime.SetFinalizer(p, nil)
+	return nil
+}

src/os/exec_test.go

@@ -0,0 +1,28 @@
+// Copyright 2024 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_test
+
+import (
+	. "os"
+	"testing"
+)
+
+func TestFindProcess(t *testing.T) {
+	// NOTE: For now, we only test the Linux case since only exec_posix.go is currently the only implementation.
+	// Linux guarantees that there is pid 0
+	proc, err := FindProcess(0)
+	if err != nil {
+		t.Error("FindProcess(0): wanted err == nil, got %v:", err)
+	}
+
+	if proc.Pid != 0 {
+		t.Error("Expected pid 0, got: ", proc.Pid)
+	}
+
+	pid0 := Process{Pid: 0}
+	if *proc != pid0 {
+		t.Error("Expected &Process{Pid: 0}, got", *proc)
+	}
+}