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>

1 files changed, 4 insertions, 1 deletions

diff --git a/drivers/char/Kconfig b/drivers/char/Kconfig
index dcc09739a54e..8453a49471d7 100644
--- a/drivers/char/Kconfig
+++ b/drivers/char/Kconfig
@@ -571,9 +571,12 @@ 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"