util/winutil/s4u: fix some doc comments in the s4u package

This is #cleanup

Signed-off-by: Aaron Klotz <aaron@tailscale.com>

util/winutil/s4u/s4u_windows.go

@@ -119,7 +119,7 @@ const (
 // Login logs user u into Windows on behalf of service srcName, loads the user's
 // profile, and returns a Session that may be used for impersonating that user,
 // or optionally creating processes as that user. Logs will be written to logf,
-// if provided.  srcName must be non-empty, ASCII-only, and no longer than 8
+// if provided. srcName must be non-empty, ASCII-only, and no longer than 8
 // characters.
 //
 // The current OS thread's access token must have SeTcbPrivilege.
@@ -281,10 +281,11 @@ type startProcessOpts struct {
 }
 
 // StartProcess creates a new process running under ss via cmdLineInfo.
-// The process will be started with its working directory set to the S4U user's
+// The process will either be started with its working directory set to the S4U
-// profile directory and its environment set to the S4U user's environment.
+// user's profile directory, or for Administrative users, the system32
-// extraEnv, when specified, contains any additional environment variables to
+// directory. The child process will receive the S4U user's environment.
-// be added to the process's environment.
+// extraEnv, when specified, contains any additional environment
+// variables to be inserted into the environment.
 //
 // If called after ss has already been closed, StartProcess will panic.
 func (ss *Session) StartProcess(cmdLineInfo winutil.CommandLineInfo, extraEnv map[string]string) (psp *Process, err error) {
@@ -302,10 +303,11 @@ func (ss *Session) StartProcess(cmdLineInfo winutil.CommandLineInfo, extraEnv ma
 // StartProcessWithPTY creates a new process running under ss via cmdLineInfo
 // with a pseudoconsole initialized to initialPtySize. The resulting Process
 // will return non-nil values from Stdin and Stdout, but Stderr will return nil.
-// The process will be started with its working directory set to the S4U user's
+// The process will either be started with its working directory set to the S4U
-// profile directory and its environment set to the S4U user's environment.
+// user's profile directory, or for Administrative users, the system32
-// extraEnv, when specified, contains any additional environment variables to
+// directory. The child process will receive the S4U user's environment.
-// be added to the process's environment.
+// extraEnv, when specified, contains any additional environment
+// variables to be inserted into the environment.
 //
 // If called after ss has already been closed, StartProcessWithPTY will panic.
 func (ss *Session) StartProcessWithPTY(cmdLineInfo winutil.CommandLineInfo, extraEnv map[string]string, initialPtySize windows.Coord) (psp *Process, err error) {
@@ -324,10 +326,11 @@ func (ss *Session) StartProcessWithPTY(cmdLineInfo winutil.CommandLineInfo, extr
 // StartProcessWithPipes creates a new process running under ss via cmdLineInfo
 // with all standard handles set to pipes. The resulting Process will return
 // non-nil values from Stdin, Stdout, and Stderr.
-// The process will be started with its working directory set to the S4U user's
+// The process will either be started with its working directory set to the S4U
-// profile directory and its environment set to the S4U user's environment.
+// user's profile directory, or for Administrative users, the system32
-// extraEnv, when specified, contains any additional environment variables to
+// directory. The child process will receive the S4U user's environment.
-// be added to the process's environment.
+// extraEnv, when specified, contains any additional environment
+// variables to be inserted into the environment.
 //
 // If called after ss has already been closed, StartProcessWithPipes will panic.
 func (ss *Session) StartProcessWithPipes(cmdLineInfo winutil.CommandLineInfo, extraEnv map[string]string) (psp *Process, err error) {

util/winutil/winutil_windows.go

@@ -647,7 +647,8 @@ func LogonSessionID(token windows.Token) (logonSessionID windows.LUID, err error
 	return origin.originatingLogonSession, nil
 }
 
-// BufUnit is a type constraint for buffers passed into AllocateContiguousBuffer.
+// BufUnit is a type constraint for buffers passed into AllocateContiguousBuffer
+// and SetNTString.
 type BufUnit interface {
 	byte | uint16
 }