Merge pull request microsoft#297 from jstarks/ctty

gcs: Prevent GCS crashing when external process exits
dcantah · Apr 22, 2019 · 92d537f · 92d537f
2 parents e979295 + 7009c9e
commit 92d537f
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Showing 2 changed files with 11 additions and 2 deletions.
diff --git a/init/init.c b/init/init.c
@@ -282,7 +282,9 @@ int reap_until(pid_t until_pid) {
                 }
                 return WEXITSTATUS(status);
             }
-            fputs("child exited by signal\n", stderr);
+            fputs("child exited by signal: ", stderr);
+            fputs(strsignal(WTERMSIG(status)), stderr);
+            fputs("\n", stderr);
             return 128 + WTERMSIG(status);
         }
     }

diff --git a/service/gcs/core/gcs/gcs.go b/service/gcs/core/gcs/gcs.go
@@ -587,7 +587,7 @@ func (c *gcsCore) RunExternalProcess(params prot.ProcessParameters, conSettings
 		}()
 
 		var console *os.File
-		console, err = os.OpenFile(consolePath, os.O_RDWR, 0777)
+		console, err = os.OpenFile(consolePath, os.O_RDWR|syscall.O_NOCTTY, 0777)
 		if err != nil {
 			return -1, errors.Wrap(err, "failed to open console file for external process")
 		}
@@ -597,6 +597,13 @@ func (c *gcsCore) RunExternalProcess(params prot.ProcessParameters, conSettings
 		cmd.Stdin = console
 		cmd.Stdout = console
 		cmd.Stderr = console
+		// Make the child process a session leader and adopt the pty as
+		// the controlling terminal.
+		cmd.SysProcAttr = &syscall.SysProcAttr{
+			Setsid:  true,
+			Setctty: true,
+			Ctty:    syscall.Stdin,
+		}
 	} else {
 		var fileSet *stdio.FileSet
 		fileSet, err = stdioSet.Files()