char: lack of bool string made CONFIG_DEVPORT always on

commit f2cfa58b136e4b06a9b9db7af5ef62fbb5992f62 upstream.

Without a bool string present, using "# CONFIG_DEVPORT is not set" in
defconfig files would not actually unset devport. This esnured that
/dev/port was always on, but there are reasons a user may wish to
disable it (smaller kernel, attack surface reduction) if it's not being
used. Adding a message here in order to make this user visible.

Signed-off-by: Max Bires <jbires@google.com>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/char/Kconfig b/drivers/char/Kconfig
index b130d38..3143db5 100644 (file)
--- a/drivers/char/Kconfig
+++ b/drivers/char/Kconfig
@@ -583,9 +583,12 @@ config TELCLOCK
          controlling the behavior of this hardware.
 
 config DEVPORT
-       bool
+       bool "/dev/port character device"
        depends on ISA || PCI
        default y
+       help
+         Say Y here if you want to support the /dev/port device. The /dev/port
+         device is similar to /dev/mem, but for I/O ports.
 
 source "drivers/s390/char/Kconfig"