On Tue, Dec 13, 2016 at 1:37 PM, Arnd Bergmann <a...@arndb.de> wrote: > > On Tuesday, December 13, 2016 1:30:39 PM CET Max Bires wrote: > > While trying to turn off the port device in defconfig, I ran into a bug > > caused by the fact that the Kconfig for port didn't have a string after the > > bool declaration. I fixed this in the attached patch (though I figure the > > description might need tuning up). Let me know if there's anything else I > > need to do. > > The change looks reasonable, however there are a few things to improve > to get the patch applied: > > - clarify that the current behavior is not a bug, but was done intentionally. > Making the option user-visible would help avoid a potential attack vector > and make the kernel smaller, both of which are useful. > > - remove the "Change-id" line from the submission, it has no meaning in > an upstream kernel > > - send the patch inline rather than as an attachment, this is usually done > with git-send-email. > > Arnd -First and second points have been addressed; I had some trouble with send-email, so let me know if the following isn't acceptable inlining.
>From c4a21c2ac0c587094000a3daeb13eec6056dc63f Mon Sep 17 00:00:00 2001 From: Max <jbi...@google.com> Date: Fri, 9 Dec 2016 15:16:47 -0800 Subject: [PATCH] char: lack of bool string made CONFIG_DEVPORT always on Without a bool string present, using "# CONFIG_DEVPORT is not set" in defconfig files would not actually unset devport. This ensured 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 <jbi...@google.com> --- drivers/char/Kconfig | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-) diff --git a/drivers/char/Kconfig b/drivers/char/Kconfig index 7ad3127..70e626c 100644 --- a/drivers/char/Kconfig +++ b/drivers/char/Kconfig @@ -589,10 +589,13 @@ config TELCLOCK controlling the behavior of this hardware. config DEVPORT - bool + bool "/dev/port character device" depends on !M68K 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. config DCC_TTY tristate "DCC tty driver" -- 2.8.0.rc3.226.g39d4020