From 8bdb235b552d760613f9e97679b38029fa2e6b45 Mon Sep 17 00:00:00 2001
From: rzpt <51346452+rzpt@users.noreply.github.com>
Date: Tue, 9 Jun 2020 11:12:47 -0700
Subject: [PATCH] fix process running check (#130)

Fix false positive process detection when an unrelated thread's id matches the old process id.
---
 Gopkg.lock                                    |   8 +-
 changelog/@unreleased/pr-130.v2.yml           |   5 +
 init/cli/lib.go                               |  40 ++-
 init/cli/stop.go                              |  12 +-
 vendor/github.com/mitchellh/go-ps/.gitignore  |   1 +
 vendor/github.com/mitchellh/go-ps/.travis.yml |   4 +
 vendor/github.com/mitchellh/go-ps/LICENSE.md  |  21 ++
 vendor/github.com/mitchellh/go-ps/README.md   |  34 +++
 vendor/github.com/mitchellh/go-ps/Vagrantfile |  43 +++
 vendor/github.com/mitchellh/go-ps/go.mod      |   3 +
 vendor/github.com/mitchellh/go-ps/process.go  |  40 +++
 .../mitchellh/go-ps/process_darwin.go         | 138 ++++++++++
 .../mitchellh/go-ps/process_freebsd.go        | 260 ++++++++++++++++++
 .../mitchellh/go-ps/process_linux.go          |  35 +++
 .../mitchellh/go-ps/process_solaris.go        |  96 +++++++
 .../mitchellh/go-ps/process_unix.go           |  95 +++++++
 .../mitchellh/go-ps/process_windows.go        | 119 ++++++++
 17 files changed, 944 insertions(+), 10 deletions(-)
 create mode 100644 changelog/@unreleased/pr-130.v2.yml
 create mode 100644 vendor/github.com/mitchellh/go-ps/.gitignore
 create mode 100644 vendor/github.com/mitchellh/go-ps/.travis.yml
 create mode 100644 vendor/github.com/mitchellh/go-ps/LICENSE.md
 create mode 100644 vendor/github.com/mitchellh/go-ps/README.md
 create mode 100644 vendor/github.com/mitchellh/go-ps/Vagrantfile
 create mode 100644 vendor/github.com/mitchellh/go-ps/go.mod
 create mode 100644 vendor/github.com/mitchellh/go-ps/process.go
 create mode 100644 vendor/github.com/mitchellh/go-ps/process_darwin.go
 create mode 100644 vendor/github.com/mitchellh/go-ps/process_freebsd.go
 create mode 100644 vendor/github.com/mitchellh/go-ps/process_linux.go
 create mode 100644 vendor/github.com/mitchellh/go-ps/process_solaris.go
 create mode 100644 vendor/github.com/mitchellh/go-ps/process_unix.go
 create mode 100644 vendor/github.com/mitchellh/go-ps/process_windows.go

diff --git a/Gopkg.lock b/Gopkg.lock
index b26c526f..29dab287 100644
--- a/Gopkg.lock
+++ b/Gopkg.lock
@@ -7,6 +7,12 @@
   revision = "346938d642f2ec3594ed81d874461961cd0faa76"
   version = "v1.1.0"
 
+[[projects]]
+  name = "github.com/mitchellh/go-ps"
+  packages = ["."]
+  revision = "147ff83818ae939913b2e20b91ae3cd6c391771c"
+  version = "v1.0.0"
+
 [[projects]]
   branch = "master"
   name = "github.com/mitchellh/go-wordwrap"
@@ -70,6 +76,6 @@
 [solve-meta]
   analyzer-name = "dep"
   analyzer-version = 1
-  inputs-digest = "f5acf16fae9932555264d1e8a827ed3a8484d71ccb4e16b1dc86df885e5ac063"
+  inputs-digest = "04cb028c8bb597646fb5c39d30a5d686a6a513923f502866aa65d68f138946f6"
   solver-name = "gps-cdcl"
   solver-version = 1
diff --git a/changelog/@unreleased/pr-130.v2.yml b/changelog/@unreleased/pr-130.v2.yml
new file mode 100644
index 00000000..cd6a468f
--- /dev/null
+++ b/changelog/@unreleased/pr-130.v2.yml
@@ -0,0 +1,5 @@
+type: fix
+fix:
+  description: Fix false positive process detection when an unrelated thread's id matches the old process id.
+  links:
+  - https://github.com/palantir/go-java-launcher/pull/130
diff --git a/init/cli/lib.go b/init/cli/lib.go
index 18af93ae..2df5a679 100644
--- a/init/cli/lib.go
+++ b/init/cli/lib.go
@@ -24,6 +24,7 @@ import (
 	"strings"
 	"syscall"
 
+	ps "github.com/mitchellh/go-ps"
 	"github.com/palantir/pkg/cli"
 	"github.com/pkg/errors"
 
@@ -108,7 +109,11 @@ func getCmdProcess(name string) (*int, *os.Process, error) {
 		return nil, nil, errors.Wrap(err, "pid file did not contain an integer")
 	}
 
-	if running, proc := isPidRunning(pid); running {
+	running, proc, err := isPidRunning(pid)
+	if err != nil {
+		return nil, nil, err
+	}
+	if running {
 		return &pid, proc, nil
 	}
 	return &pid, nil, nil
@@ -146,16 +151,37 @@ func getConfiguredCommands(ctx cli.Context, loggers launchlib.ServiceLoggers) (m
 	return cmds, nil
 }
 
-func isPidRunning(pid int) (bool, *os.Process) {
+func isPidRunning(pid int) (bool, *os.Process, error) {
 	// Docs say FindProcess always succeeds on Unix.
 	proc, _ := os.FindProcess(pid)
-	if isProcRunning(proc) {
-		return true, proc
+	running, err := isProcRunning(proc)
+	if err != nil {
+		return false, nil, err
 	}
-	return false, nil
+	if running {
+		return true, proc, nil
+	}
+	return false, nil, nil
 }
 
-func isProcRunning(proc *os.Process) bool {
+func isProcRunning(proc *os.Process) (bool, error) {
 	// This is the way to check if a process exists: https://linux.die.net/man/2/kill.
-	return proc.Signal(syscall.Signal(0)) == nil
+	// On linux, this may respond true if there is a thread running with the same id.
+	running := proc.Signal(syscall.Signal(0)) == nil
+	if !running {
+		return false, nil
+	}
+
+	// On linux, iterating over processes will only return running processes. Unfortunately,
+	// getting exactly the one pid will also return a thread of the same id.
+	procs, err := ps.Processes()
+	if err != nil {
+		return false, err
+	}
+	for _, p := range procs {
+		if p.Pid() == proc.Pid {
+			return true, nil
+		}
+	}
+	return false, nil
 }
diff --git a/init/cli/stop.go b/init/cli/stop.go
index a9d381ca..4d46b9f9 100644
--- a/init/cli/stop.go
+++ b/init/cli/stop.go
@@ -106,7 +106,11 @@ func waitForServiceToStop(ctx cli.Context, procs map[string]*os.Process) error {
 		select {
 		case <-ticker.Chan():
 			for name, remainingProc := range procs {
-				if !isProcRunning(remainingProc) {
+				running, err := isProcRunning(remainingProc)
+				if err != nil {
+					return err
+				}
+				if !running {
 					delete(procs, name)
 				}
 			}
@@ -116,7 +120,11 @@ func waitForServiceToStop(ctx cli.Context, procs map[string]*os.Process) error {
 		case <-timer.Chan():
 			killedProcs := make([]string, 0, len(procs))
 			for name, remainingProc := range procs {
-				if isProcRunning(remainingProc) {
+				running, err := isProcRunning(remainingProc)
+				if err != nil {
+					return err
+				}
+				if running {
 					if err := remainingProc.Kill(); err != nil {
 						// If this actually errors, something is probably seriously wrong.
 						// Just stop immediately.
diff --git a/vendor/github.com/mitchellh/go-ps/.gitignore b/vendor/github.com/mitchellh/go-ps/.gitignore
new file mode 100644
index 00000000..a977916f
--- /dev/null
+++ b/vendor/github.com/mitchellh/go-ps/.gitignore
@@ -0,0 +1 @@
+.vagrant/
diff --git a/vendor/github.com/mitchellh/go-ps/.travis.yml b/vendor/github.com/mitchellh/go-ps/.travis.yml
new file mode 100644
index 00000000..8f794f71
--- /dev/null
+++ b/vendor/github.com/mitchellh/go-ps/.travis.yml
@@ -0,0 +1,4 @@
+language: go
+
+go:
+  - 1.2.1
diff --git a/vendor/github.com/mitchellh/go-ps/LICENSE.md b/vendor/github.com/mitchellh/go-ps/LICENSE.md
new file mode 100644
index 00000000..22985159
--- /dev/null
+++ b/vendor/github.com/mitchellh/go-ps/LICENSE.md
@@ -0,0 +1,21 @@
+The MIT License (MIT)
+
+Copyright (c) 2014 Mitchell Hashimoto
+
+Permission is hereby granted, free of charge, to any person obtaining a copy
+of this software and associated documentation files (the "Software"), to deal
+in the Software without restriction, including without limitation the rights
+to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+copies of the Software, and to permit persons to whom the Software is
+furnished to do so, subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included in
+all copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+THE SOFTWARE.
diff --git a/vendor/github.com/mitchellh/go-ps/README.md b/vendor/github.com/mitchellh/go-ps/README.md
new file mode 100644
index 00000000..4e3d0e14
--- /dev/null
+++ b/vendor/github.com/mitchellh/go-ps/README.md
@@ -0,0 +1,34 @@
+# Process List Library for Go [![GoDoc](https://godoc.org/github.com/mitchellh/go-ps?status.png)](https://godoc.org/github.com/mitchellh/go-ps)
+
+go-ps is a library for Go that implements OS-specific APIs to list and
+manipulate processes in a platform-safe way. The library can find and
+list processes on Linux, Mac OS X, Solaris, and Windows.
+
+If you're new to Go, this library has a good amount of advanced Go educational
+value as well. It uses some advanced features of Go: build tags, accessing
+DLL methods for Windows, cgo for Darwin, etc.
+
+How it works:
+
+  * **Darwin** uses the `sysctl` syscall to retrieve the process table.
+  * **Unix** uses the procfs at `/proc` to inspect the process tree.
+  * **Windows** uses the Windows API, and methods such as
+    `CreateToolhelp32Snapshot` to get a point-in-time snapshot of
+    the process table.
+
+## Installation
+
+Install using standard `go get`:
+
+```
+$ go get github.com/mitchellh/go-ps
+...
+```
+
+## TODO
+
+Want to contribute? Here is a short TODO list of things that aren't
+implemented for this library that would be nice:
+
+  * FreeBSD support
+  * Plan9 support
diff --git a/vendor/github.com/mitchellh/go-ps/Vagrantfile b/vendor/github.com/mitchellh/go-ps/Vagrantfile
new file mode 100644
index 00000000..61662ab1
--- /dev/null
+++ b/vendor/github.com/mitchellh/go-ps/Vagrantfile
@@ -0,0 +1,43 @@
+# -*- mode: ruby -*-
+# vi: set ft=ruby :
+
+# Vagrantfile API/syntax version. Don't touch unless you know what you're doing!
+VAGRANTFILE_API_VERSION = "2"
+
+Vagrant.configure(VAGRANTFILE_API_VERSION) do |config|
+  config.vm.box = "chef/ubuntu-12.04"
+
+  config.vm.provision "shell", inline: $script
+
+  ["vmware_fusion", "vmware_workstation"].each do |p|
+    config.vm.provider "p" do |v|
+      v.vmx["memsize"] = "1024"
+      v.vmx["numvcpus"] = "2"
+      v.vmx["cpuid.coresPerSocket"] = "1"
+    end
+  end
+end
+
+$script = <<SCRIPT
+SRCROOT="/opt/go"
+
+# Install Go
+sudo apt-get update
+sudo apt-get install -y build-essential mercurial
+sudo hg clone -u release https://code.google.com/p/go ${SRCROOT}
+cd ${SRCROOT}/src
+sudo ./all.bash
+
+# Setup the GOPATH
+sudo mkdir -p /opt/gopath
+cat <<EOF >/tmp/gopath.sh
+export GOPATH="/opt/gopath"
+export PATH="/opt/go/bin:\$GOPATH/bin:\$PATH"
+EOF
+sudo mv /tmp/gopath.sh /etc/profile.d/gopath.sh
+sudo chmod 0755 /etc/profile.d/gopath.sh
+
+# Make sure the gopath is usable by bamboo
+sudo chown -R vagrant:vagrant $SRCROOT
+sudo chown -R vagrant:vagrant /opt/gopath
+SCRIPT
diff --git a/vendor/github.com/mitchellh/go-ps/go.mod b/vendor/github.com/mitchellh/go-ps/go.mod
new file mode 100644
index 00000000..03432797
--- /dev/null
+++ b/vendor/github.com/mitchellh/go-ps/go.mod
@@ -0,0 +1,3 @@
+module github.com/mitchellh/go-ps
+
+go 1.13
diff --git a/vendor/github.com/mitchellh/go-ps/process.go b/vendor/github.com/mitchellh/go-ps/process.go
new file mode 100644
index 00000000..2b5e8ed2
--- /dev/null
+++ b/vendor/github.com/mitchellh/go-ps/process.go
@@ -0,0 +1,40 @@
+// ps provides an API for finding and listing processes in a platform-agnostic
+// way.
+//
+// NOTE: If you're reading these docs online via GoDocs or some other system,
+// you might only see the Unix docs. This project makes heavy use of
+// platform-specific implementations. We recommend reading the source if you
+// are interested.
+package ps
+
+// Process is the generic interface that is implemented on every platform
+// and provides common operations for processes.
+type Process interface {
+	// Pid is the process ID for this process.
+	Pid() int
+
+	// PPid is the parent process ID for this process.
+	PPid() int
+
+	// Executable name running this process. This is not a path to the
+	// executable.
+	Executable() string
+}
+
+// Processes returns all processes.
+//
+// This of course will be a point-in-time snapshot of when this method was
+// called. Some operating systems don't provide snapshot capability of the
+// process table, in which case the process table returned might contain
+// ephemeral entities that happened to be running when this was called.
+func Processes() ([]Process, error) {
+	return processes()
+}
+
+// FindProcess looks up a single process by pid.
+//
+// Process will be nil and error will be nil if a matching process is
+// not found.
+func FindProcess(pid int) (Process, error) {
+	return findProcess(pid)
+}
diff --git a/vendor/github.com/mitchellh/go-ps/process_darwin.go b/vendor/github.com/mitchellh/go-ps/process_darwin.go
new file mode 100644
index 00000000..5ee87fb6
--- /dev/null
+++ b/vendor/github.com/mitchellh/go-ps/process_darwin.go
@@ -0,0 +1,138 @@
+// +build darwin
+
+package ps
+
+import (
+	"bytes"
+	"encoding/binary"
+	"syscall"
+	"unsafe"
+)
+
+type DarwinProcess struct {
+	pid    int
+	ppid   int
+	binary string
+}
+
+func (p *DarwinProcess) Pid() int {
+	return p.pid
+}
+
+func (p *DarwinProcess) PPid() int {
+	return p.ppid
+}
+
+func (p *DarwinProcess) Executable() string {
+	return p.binary
+}
+
+func findProcess(pid int) (Process, error) {
+	ps, err := processes()
+	if err != nil {
+		return nil, err
+	}
+
+	for _, p := range ps {
+		if p.Pid() == pid {
+			return p, nil
+		}
+	}
+
+	return nil, nil
+}
+
+func processes() ([]Process, error) {
+	buf, err := darwinSyscall()
+	if err != nil {
+		return nil, err
+	}
+
+	procs := make([]*kinfoProc, 0, 50)
+	k := 0
+	for i := _KINFO_STRUCT_SIZE; i < buf.Len(); i += _KINFO_STRUCT_SIZE {
+		proc := &kinfoProc{}
+		err = binary.Read(bytes.NewBuffer(buf.Bytes()[k:i]), binary.LittleEndian, proc)
+		if err != nil {
+			return nil, err
+		}
+
+		k = i
+		procs = append(procs, proc)
+	}
+
+	darwinProcs := make([]Process, len(procs))
+	for i, p := range procs {
+		darwinProcs[i] = &DarwinProcess{
+			pid:    int(p.Pid),
+			ppid:   int(p.PPid),
+			binary: darwinCstring(p.Comm),
+		}
+	}
+
+	return darwinProcs, nil
+}
+
+func darwinCstring(s [16]byte) string {
+	i := 0
+	for _, b := range s {
+		if b != 0 {
+			i++
+		} else {
+			break
+		}
+	}
+
+	return string(s[:i])
+}
+
+func darwinSyscall() (*bytes.Buffer, error) {
+	mib := [4]int32{_CTRL_KERN, _KERN_PROC, _KERN_PROC_ALL, 0}
+	size := uintptr(0)
+
+	_, _, errno := syscall.Syscall6(
+		syscall.SYS___SYSCTL,
+		uintptr(unsafe.Pointer(&mib[0])),
+		4,
+		0,
+		uintptr(unsafe.Pointer(&size)),
+		0,
+		0)
+
+	if errno != 0 {
+		return nil, errno
+	}
+
+	bs := make([]byte, size)
+	_, _, errno = syscall.Syscall6(
+		syscall.SYS___SYSCTL,
+		uintptr(unsafe.Pointer(&mib[0])),
+		4,
+		uintptr(unsafe.Pointer(&bs[0])),
+		uintptr(unsafe.Pointer(&size)),
+		0,
+		0)
+
+	if errno != 0 {
+		return nil, errno
+	}
+
+	return bytes.NewBuffer(bs[0:size]), nil
+}
+
+const (
+	_CTRL_KERN         = 1
+	_KERN_PROC         = 14
+	_KERN_PROC_ALL     = 0
+	_KINFO_STRUCT_SIZE = 648
+)
+
+type kinfoProc struct {
+	_    [40]byte
+	Pid  int32
+	_    [199]byte
+	Comm [16]byte
+	_    [301]byte
+	PPid int32
+	_    [84]byte
+}
diff --git a/vendor/github.com/mitchellh/go-ps/process_freebsd.go b/vendor/github.com/mitchellh/go-ps/process_freebsd.go
new file mode 100644
index 00000000..130acbe6
--- /dev/null
+++ b/vendor/github.com/mitchellh/go-ps/process_freebsd.go
@@ -0,0 +1,260 @@
+// +build freebsd
+
+package ps
+
+import (
+	"bytes"
+	"encoding/binary"
+	"syscall"
+	"unsafe"
+)
+
+// copied from sys/sysctl.h
+const (
+	CTL_KERN           = 1  // "high kernel": proc, limits
+	KERN_PROC          = 14 // struct: process entries
+	KERN_PROC_PID      = 1  // by process id
+	KERN_PROC_PROC     = 8  // only return procs
+	KERN_PROC_PATHNAME = 12 // path to executable
+)
+
+// copied from sys/user.h
+type Kinfo_proc struct {
+	Ki_structsize   int32
+	Ki_layout       int32
+	Ki_args         int64
+	Ki_paddr        int64
+	Ki_addr         int64
+	Ki_tracep       int64
+	Ki_textvp       int64
+	Ki_fd           int64
+	Ki_vmspace      int64
+	Ki_wchan        int64
+	Ki_pid          int32
+	Ki_ppid         int32
+	Ki_pgid         int32
+	Ki_tpgid        int32
+	Ki_sid          int32
+	Ki_tsid         int32
+	Ki_jobc         [2]byte
+	Ki_spare_short1 [2]byte
+	Ki_tdev         int32
+	Ki_siglist      [16]byte
+	Ki_sigmask      [16]byte
+	Ki_sigignore    [16]byte
+	Ki_sigcatch     [16]byte
+	Ki_uid          int32
+	Ki_ruid         int32
+	Ki_svuid        int32
+	Ki_rgid         int32
+	Ki_svgid        int32
+	Ki_ngroups      [2]byte
+	Ki_spare_short2 [2]byte
+	Ki_groups       [64]byte
+	Ki_size         int64
+	Ki_rssize       int64
+	Ki_swrss        int64
+	Ki_tsize        int64
+	Ki_dsize        int64
+	Ki_ssize        int64
+	Ki_xstat        [2]byte
+	Ki_acflag       [2]byte
+	Ki_pctcpu       int32
+	Ki_estcpu       int32
+	Ki_slptime      int32
+	Ki_swtime       int32
+	Ki_cow          int32
+	Ki_runtime      int64
+	Ki_start        [16]byte
+	Ki_childtime    [16]byte
+	Ki_flag         int64
+	Ki_kiflag       int64
+	Ki_traceflag    int32
+	Ki_stat         [1]byte
+	Ki_nice         [1]byte
+	Ki_lock         [1]byte
+	Ki_rqindex      [1]byte
+	Ki_oncpu        [1]byte
+	Ki_lastcpu      [1]byte
+	Ki_ocomm        [17]byte
+	Ki_wmesg        [9]byte
+	Ki_login        [18]byte
+	Ki_lockname     [9]byte
+	Ki_comm         [20]byte
+	Ki_emul         [17]byte
+	Ki_sparestrings [68]byte
+	Ki_spareints    [36]byte
+	Ki_cr_flags     int32
+	Ki_jid          int32
+	Ki_numthreads   int32
+	Ki_tid          int32
+	Ki_pri          int32
+	Ki_rusage       [144]byte
+	Ki_rusage_ch    [144]byte
+	Ki_pcb          int64
+	Ki_kstack       int64
+	Ki_udata        int64
+	Ki_tdaddr       int64
+	Ki_spareptrs    [48]byte
+	Ki_spareint64s  [96]byte
+	Ki_sflag        int64
+	Ki_tdflags      int64
+}
+
+// UnixProcess is an implementation of Process that contains Unix-specific
+// fields and information.
+type UnixProcess struct {
+	pid   int
+	ppid  int
+	state rune
+	pgrp  int
+	sid   int
+
+	binary string
+}
+
+func (p *UnixProcess) Pid() int {
+	return p.pid
+}
+
+func (p *UnixProcess) PPid() int {
+	return p.ppid
+}
+
+func (p *UnixProcess) Executable() string {
+	return p.binary
+}
+
+// Refresh reloads all the data associated with this process.
+func (p *UnixProcess) Refresh() error {
+
+	mib := []int32{CTL_KERN, KERN_PROC, KERN_PROC_PID, int32(p.pid)}
+
+	buf, length, err := call_syscall(mib)
+	if err != nil {
+		return err
+	}
+	proc_k := Kinfo_proc{}
+	if length != uint64(unsafe.Sizeof(proc_k)) {
+		return err
+	}
+
+	k, err := parse_kinfo_proc(buf)
+	if err != nil {
+		return err
+	}
+
+	p.ppid, p.pgrp, p.sid, p.binary = copy_params(&k)
+	return nil
+}
+
+func copy_params(k *Kinfo_proc) (int, int, int, string) {
+	n := -1
+	for i, b := range k.Ki_comm {
+		if b == 0 {
+			break
+		}
+		n = i + 1
+	}
+	comm := string(k.Ki_comm[:n])
+
+	return int(k.Ki_ppid), int(k.Ki_pgid), int(k.Ki_sid), comm
+}
+
+func findProcess(pid int) (Process, error) {
+	mib := []int32{CTL_KERN, KERN_PROC, KERN_PROC_PATHNAME, int32(pid)}
+
+	_, _, err := call_syscall(mib)
+	if err != nil {
+		return nil, err
+	}
+
+	return newUnixProcess(pid)
+}
+
+func processes() ([]Process, error) {
+	results := make([]Process, 0, 50)
+
+	mib := []int32{CTL_KERN, KERN_PROC, KERN_PROC_PROC, 0}
+	buf, length, err := call_syscall(mib)
+	if err != nil {
+		return results, err
+	}
+
+	// get kinfo_proc size
+	k := Kinfo_proc{}
+	procinfo_len := int(unsafe.Sizeof(k))
+	count := int(length / uint64(procinfo_len))
+
+	// parse buf to procs
+	for i := 0; i < count; i++ {
+		b := buf[i*procinfo_len : i*procinfo_len+procinfo_len]
+		k, err := parse_kinfo_proc(b)
+		if err != nil {
+			continue
+		}
+		p, err := newUnixProcess(int(k.Ki_pid))
+		if err != nil {
+			continue
+		}
+		p.ppid, p.pgrp, p.sid, p.binary = copy_params(&k)
+
+		results = append(results, p)
+	}
+
+	return results, nil
+}
+
+func parse_kinfo_proc(buf []byte) (Kinfo_proc, error) {
+	var k Kinfo_proc
+	br := bytes.NewReader(buf)
+	err := binary.Read(br, binary.LittleEndian, &k)
+	if err != nil {
+		return k, err
+	}
+
+	return k, nil
+}
+
+func call_syscall(mib []int32) ([]byte, uint64, error) {
+	miblen := uint64(len(mib))
+
+	// get required buffer size
+	length := uint64(0)
+	_, _, err := syscall.RawSyscall6(
+		syscall.SYS___SYSCTL,
+		uintptr(unsafe.Pointer(&mib[0])),
+		uintptr(miblen),
+		0,
+		uintptr(unsafe.Pointer(&length)),
+		0,
+		0)
+	if err != 0 {
+		b := make([]byte, 0)
+		return b, length, err
+	}
+	if length == 0 {
+		b := make([]byte, 0)
+		return b, length, err
+	}
+	// get proc info itself
+	buf := make([]byte, length)
+	_, _, err = syscall.RawSyscall6(
+		syscall.SYS___SYSCTL,
+		uintptr(unsafe.Pointer(&mib[0])),
+		uintptr(miblen),
+		uintptr(unsafe.Pointer(&buf[0])),
+		uintptr(unsafe.Pointer(&length)),
+		0,
+		0)
+	if err != 0 {
+		return buf, length, err
+	}
+
+	return buf, length, nil
+}
+
+func newUnixProcess(pid int) (*UnixProcess, error) {
+	p := &UnixProcess{pid: pid}
+	return p, p.Refresh()
+}
diff --git a/vendor/github.com/mitchellh/go-ps/process_linux.go b/vendor/github.com/mitchellh/go-ps/process_linux.go
new file mode 100644
index 00000000..c1558f78
--- /dev/null
+++ b/vendor/github.com/mitchellh/go-ps/process_linux.go
@@ -0,0 +1,35 @@
+// +build linux
+
+package ps
+
+import (
+	"fmt"
+	"io/ioutil"
+	"strings"
+)
+
+// Refresh reloads all the data associated with this process.
+func (p *UnixProcess) Refresh() error {
+	statPath := fmt.Sprintf("/proc/%d/stat", p.pid)
+	dataBytes, err := ioutil.ReadFile(statPath)
+	if err != nil {
+		return err
+	}
+
+	// First, parse out the image name
+	data := string(dataBytes)
+	binStart := strings.IndexRune(data, '(') + 1
+	binEnd := strings.IndexRune(data[binStart:], ')')
+	p.binary = data[binStart : binStart+binEnd]
+
+	// Move past the image name and start parsing the rest
+	data = data[binStart+binEnd+2:]
+	_, err = fmt.Sscanf(data,
+		"%c %d %d %d",
+		&p.state,
+		&p.ppid,
+		&p.pgrp,
+		&p.sid)
+
+	return err
+}
diff --git a/vendor/github.com/mitchellh/go-ps/process_solaris.go b/vendor/github.com/mitchellh/go-ps/process_solaris.go
new file mode 100644
index 00000000..014c4161
--- /dev/null
+++ b/vendor/github.com/mitchellh/go-ps/process_solaris.go
@@ -0,0 +1,96 @@
+// +build solaris
+
+package ps
+
+import (
+	"encoding/binary"
+	"fmt"
+	"os"
+)
+
+type ushort_t uint16
+
+type id_t int32
+type pid_t int32
+type uid_t int32
+type gid_t int32
+
+type dev_t uint64
+type size_t uint64
+type uintptr_t uint64
+
+type timestruc_t [16]byte
+
+// This is copy from /usr/include/sys/procfs.h
+type psinfo_t struct {
+	Pr_flag   int32     /* process flags (DEPRECATED; do not use) */
+	Pr_nlwp   int32     /* number of active lwps in the process */
+	Pr_pid    pid_t     /* unique process id */
+	Pr_ppid   pid_t     /* process id of parent */
+	Pr_pgid   pid_t     /* pid of process group leader */
+	Pr_sid    pid_t     /* session id */
+	Pr_uid    uid_t     /* real user id */
+	Pr_euid   uid_t     /* effective user id */
+	Pr_gid    gid_t     /* real group id */
+	Pr_egid   gid_t     /* effective group id */
+	Pr_addr   uintptr_t /* address of process */
+	Pr_size   size_t    /* size of process image in Kbytes */
+	Pr_rssize size_t    /* resident set size in Kbytes */
+	Pr_pad1   size_t
+	Pr_ttydev dev_t /* controlling tty device (or PRNODEV) */
+
+	// Guess this following 2 ushort_t values require a padding to properly
+	// align to the 64bit mark.
+	Pr_pctcpu   ushort_t /* % of recent cpu time used by all lwps */
+	Pr_pctmem   ushort_t /* % of system memory used by process */
+	Pr_pad64bit [4]byte
+
+	Pr_start    timestruc_t /* process start time, from the epoch */
+	Pr_time     timestruc_t /* usr+sys cpu time for this process */
+	Pr_ctime    timestruc_t /* usr+sys cpu time for reaped children */
+	Pr_fname    [16]byte    /* name of execed file */
+	Pr_psargs   [80]byte    /* initial characters of arg list */
+	Pr_wstat    int32       /* if zombie, the wait() status */
+	Pr_argc     int32       /* initial argument count */
+	Pr_argv     uintptr_t   /* address of initial argument vector */
+	Pr_envp     uintptr_t   /* address of initial environment vector */
+	Pr_dmodel   [1]byte     /* data model of the process */
+	Pr_pad2     [3]byte
+	Pr_taskid   id_t      /* task id */
+	Pr_projid   id_t      /* project id */
+	Pr_nzomb    int32     /* number of zombie lwps in the process */
+	Pr_poolid   id_t      /* pool id */
+	Pr_zoneid   id_t      /* zone id */
+	Pr_contract id_t      /* process contract */
+	Pr_filler   int32     /* reserved for future use */
+	Pr_lwp      [128]byte /* information for representative lwp */
+}
+
+func (p *UnixProcess) Refresh() error {
+	var psinfo psinfo_t
+
+	path := fmt.Sprintf("/proc/%d/psinfo", p.pid)
+	fh, err := os.Open(path)
+	if err != nil {
+		return err
+	}
+	defer fh.Close()
+
+	err = binary.Read(fh, binary.LittleEndian, &psinfo)
+	if err != nil {
+		return err
+	}
+
+	p.ppid = int(psinfo.Pr_ppid)
+	p.binary = toString(psinfo.Pr_fname[:], 16)
+	return nil
+}
+
+func toString(array []byte, len int) string {
+	for i := 0; i < len; i++ {
+		if array[i] == 0 {
+			return string(array[:i])
+		}
+	}
+	return string(array[:])
+}
diff --git a/vendor/github.com/mitchellh/go-ps/process_unix.go b/vendor/github.com/mitchellh/go-ps/process_unix.go
new file mode 100644
index 00000000..cd217a80
--- /dev/null
+++ b/vendor/github.com/mitchellh/go-ps/process_unix.go
@@ -0,0 +1,95 @@
+// +build linux solaris
+
+package ps
+
+import (
+	"fmt"
+	"io"
+	"os"
+	"strconv"
+)
+
+// UnixProcess is an implementation of Process that contains Unix-specific
+// fields and information.
+type UnixProcess struct {
+	pid   int
+	ppid  int
+	state rune
+	pgrp  int
+	sid   int
+
+	binary string
+}
+
+func (p *UnixProcess) Pid() int {
+	return p.pid
+}
+
+func (p *UnixProcess) PPid() int {
+	return p.ppid
+}
+
+func (p *UnixProcess) Executable() string {
+	return p.binary
+}
+
+func findProcess(pid int) (Process, error) {
+	dir := fmt.Sprintf("/proc/%d", pid)
+	_, err := os.Stat(dir)
+	if err != nil {
+		if os.IsNotExist(err) {
+			return nil, nil
+		}
+
+		return nil, err
+	}
+
+	return newUnixProcess(pid)
+}
+
+func processes() ([]Process, error) {
+	d, err := os.Open("/proc")
+	if err != nil {
+		return nil, err
+	}
+	defer d.Close()
+
+	results := make([]Process, 0, 50)
+	for {
+		names, err := d.Readdirnames(10)
+		if err == io.EOF {
+			break
+		}
+		if err != nil {
+			return nil, err
+		}
+
+		for _, name := range names {
+			// We only care if the name starts with a numeric
+			if name[0] < '0' || name[0] > '9' {
+				continue
+			}
+
+			// From this point forward, any errors we just ignore, because
+			// it might simply be that the process doesn't exist anymore.
+			pid, err := strconv.ParseInt(name, 10, 0)
+			if err != nil {
+				continue
+			}
+
+			p, err := newUnixProcess(int(pid))
+			if err != nil {
+				continue
+			}
+
+			results = append(results, p)
+		}
+	}
+
+	return results, nil
+}
+
+func newUnixProcess(pid int) (*UnixProcess, error) {
+	p := &UnixProcess{pid: pid}
+	return p, p.Refresh()
+}
diff --git a/vendor/github.com/mitchellh/go-ps/process_windows.go b/vendor/github.com/mitchellh/go-ps/process_windows.go
new file mode 100644
index 00000000..f151974e
--- /dev/null
+++ b/vendor/github.com/mitchellh/go-ps/process_windows.go
@@ -0,0 +1,119 @@
+// +build windows
+
+package ps
+
+import (
+	"fmt"
+	"syscall"
+	"unsafe"
+)
+
+// Windows API functions
+var (
+	modKernel32                  = syscall.NewLazyDLL("kernel32.dll")
+	procCloseHandle              = modKernel32.NewProc("CloseHandle")
+	procCreateToolhelp32Snapshot = modKernel32.NewProc("CreateToolhelp32Snapshot")
+	procProcess32First           = modKernel32.NewProc("Process32FirstW")
+	procProcess32Next            = modKernel32.NewProc("Process32NextW")
+)
+
+// Some constants from the Windows API
+const (
+	ERROR_NO_MORE_FILES = 0x12
+	MAX_PATH            = 260
+)
+
+// PROCESSENTRY32 is the Windows API structure that contains a process's
+// information.
+type PROCESSENTRY32 struct {
+	Size              uint32
+	CntUsage          uint32
+	ProcessID         uint32
+	DefaultHeapID     uintptr
+	ModuleID          uint32
+	CntThreads        uint32
+	ParentProcessID   uint32
+	PriorityClassBase int32
+	Flags             uint32
+	ExeFile           [MAX_PATH]uint16
+}
+
+// WindowsProcess is an implementation of Process for Windows.
+type WindowsProcess struct {
+	pid  int
+	ppid int
+	exe  string
+}
+
+func (p *WindowsProcess) Pid() int {
+	return p.pid
+}
+
+func (p *WindowsProcess) PPid() int {
+	return p.ppid
+}
+
+func (p *WindowsProcess) Executable() string {
+	return p.exe
+}
+
+func newWindowsProcess(e *PROCESSENTRY32) *WindowsProcess {
+	// Find when the string ends for decoding
+	end := 0
+	for {
+		if e.ExeFile[end] == 0 {
+			break
+		}
+		end++
+	}
+
+	return &WindowsProcess{
+		pid:  int(e.ProcessID),
+		ppid: int(e.ParentProcessID),
+		exe:  syscall.UTF16ToString(e.ExeFile[:end]),
+	}
+}
+
+func findProcess(pid int) (Process, error) {
+	ps, err := processes()
+	if err != nil {
+		return nil, err
+	}
+
+	for _, p := range ps {
+		if p.Pid() == pid {
+			return p, nil
+		}
+	}
+
+	return nil, nil
+}
+
+func processes() ([]Process, error) {
+	handle, _, _ := procCreateToolhelp32Snapshot.Call(
+		0x00000002,
+		0)
+	if handle < 0 {
+		return nil, syscall.GetLastError()
+	}
+	defer procCloseHandle.Call(handle)
+
+	var entry PROCESSENTRY32
+	entry.Size = uint32(unsafe.Sizeof(entry))
+	ret, _, _ := procProcess32First.Call(handle, uintptr(unsafe.Pointer(&entry)))
+	if ret == 0 {
+		return nil, fmt.Errorf("Error retrieving process info.")
+	}
+
+	results := make([]Process, 0, 50)
+	for {
+		results = append(results, newWindowsProcess(&entry))
+
+		ret, _, _ := procProcess32Next.Call(handle, uintptr(unsafe.Pointer(&entry)))
+		if ret == 0 {
+			break
+		}
+	}
+
+	return results, nil
+}