[PATCH 4.10 52/69] char: lack of bool string made CONFIG_DEVPORT always on

Greg Kroah-Hartman
2017-04-19T14:39:43Z

From: Max Bires <jbires@google.com>

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>

---
drivers/char/Kconfig | 5 ++++-
1 file changed, 4 insertions(+), 1 deletion(-)

--- 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"