getty: Pass tty to use by agetty via stdin

daandemeyer · daandemeyer · commit b4bf9007cbee · 2021-11-05T21:32:11.000Z
If the tty arg is set to "-", agetty uses the stdin fd as the tty.
Let's pass the tty this way so that we keep an fd open to the tty
at all times. If all fd's to a tty are closed, the kernel might
reset the tty which we want to avoid.
diff --git a/units/console-getty.service.in b/units/console-getty.service.in
@@ -23,10 +23,12 @@ ConditionPathExists=/dev/console
 # The '-o' option value tells agetty to replace 'login' arguments with an
 # option to preserve environment (-p), followed by '--' for safety, and then
 # the entered username.
-ExecStart=-/sbin/agetty -o '-p -- \\u' --noclear --keep-baud console 115200,38400,9600 $TERM
+ExecStart=-/sbin/agetty -o '-p -- \\u' --noclear --keep-baud - 115200,38400,9600 $TERM
 Type=idle
 Restart=always
 UtmpIdentifier=cons
+StandardInput=tty
+StandardOutput=tty
 TTYPath=/dev/console
 TTYReset=yes
 TTYVHangup=yes
diff --git a/units/container-getty@.service.in b/units/container-getty@.service.in
@@ -28,11 +28,13 @@ Before=rescue.service
 # The '-o' option value tells agetty to replace 'login' arguments with an
 # option to preserve environment (-p), followed by '--' for safety, and then
 # the entered username.
-ExecStart=-/sbin/agetty -o '-p -- \\u' --noclear --keep-baud pts/%I 115200,38400,9600 $TERM
+ExecStart=-/sbin/agetty -o '-p -- \\u' --noclear --keep-baud - 115200,38400,9600 $TERM
 Type=idle
 Restart=always
 RestartSec=0
 UtmpIdentifier=pts/%I
+StandardInput=tty
+StandardOutput=tty
 TTYPath=/dev/pts/%I
 TTYReset=yes
 TTYVHangup=yes
diff --git a/units/getty@.service.in b/units/getty@.service.in
@@ -38,11 +38,13 @@ ConditionPathExists=/dev/tty0
 # The '-o' option value tells agetty to replace 'login' arguments with an
 # option to preserve environment (-p), followed by '--' for safety, and then
 # the entered username.
-ExecStart=-/sbin/agetty -o '-p -- \\u' --noclear %I $TERM
+ExecStart=-/sbin/agetty -o '-p -- \\u' --noclear - $TERM
 Type=idle
 Restart=always
 RestartSec=0
 UtmpIdentifier=%I
+StandardInput=tty
+StandardOutput=tty
 TTYPath=/dev/%I
 TTYReset=yes
 TTYVHangup=yes
diff --git a/units/serial-getty@.service.in b/units/serial-getty@.service.in
@@ -33,10 +33,12 @@ Before=rescue.service
 # The '-o' option value tells agetty to replace 'login' arguments with an
 # option to preserve environment (-p), followed by '--' for safety, and then
 # the entered username.
-ExecStart=-/sbin/agetty -o '-p -- \\u' --keep-baud 115200,57600,38400,9600 %I $TERM
+ExecStart=-/sbin/agetty -o '-p -- \\u' --keep-baud 115200,57600,38400,9600 - $TERM
 Type=idle
 Restart=always
 UtmpIdentifier=%I
+StandardInput=tty
+StandardOutput=tty
 TTYPath=/dev/%I
 TTYReset=yes
 TTYVHangup=yes
