src: don't abort on EIO when restoring tty

bnoordhuis · devsnek · commit 1095635a8aaf · 2019-07-01T19:48:28.000-05:00
EIO has been observed to be returned by the Linux kernel under some circumstances. Reading through drivers/tty/tty_io*.c, it seems to indicate the tty went away. Of course none of this is documented. Fixes: #28479 PR-URL: #28490 Reviewed-By: Michaël Zasso <targos@protonmail.com> Reviewed-By: Gireesh Punathil <gpunathi@in.ibm.com> Reviewed-By: Colin Ihrig <cjihrig@gmail.com> Reviewed-By: Anna Henningsen <anna@addaleax.net> Reviewed-By: Gus Caplan <me@gus.host>
diff --git a/src/node.cc b/src/node.cc
@@ -692,7 +692,10 @@ void ResetStdio() {
       do
         err = tcsetattr(fd, TCSANOW, &s.termios);
       while (err == -1 && errno == EINTR);  // NOLINT
-      CHECK_NE(err, -1);
+      // EIO has been observed to be returned by the Linux kernel under some
+      // circumstances. Reading through drivers/tty/tty_io*.c, it seems to
+      // indicate the tty went away. Of course none of this is documented.
+      CHECK_IMPLIES(err == -1, errno == EIO);
     }
   }
 #endif  // __POSIX__

Original file line number	Diff line number	Diff line change
`@@ -692,7 +692,10 @@ void ResetStdio() {`
`692`	`692`	`do`
`693`	`693`	`err = tcsetattr(fd, TCSANOW, &s.termios);`
`694`	`694`	`while (err == -1 && errno == EINTR); // NOLINT`
`695`		`- CHECK_NE(err, -1);`
	`695`	`+ // EIO has been observed to be returned by the Linux kernel under some`
	`696`	`+ // circumstances. Reading through drivers/tty/tty_io*.c, it seems to`
	`697`	`+ // indicate the tty went away. Of course none of this is documented.`
	`698`	`+ CHECK_IMPLIES(err == -1, errno == EIO);`
`696`	`699`	`}`
`697`	`700`	`}`
`698`	`701`	`#endif // __POSIX__`