Re: [kernel-hardening] [PATCH v4 3/8] param: convert some "on"/"off" users to strtobool

From: David Brown
Date: Wed Jan 27 2016 - 16:11:15 EST

On Tue, Jan 19, 2016 at 10:08:37AM -0800, Kees Cook wrote:

diff --git a/kernel/time/tick-sched.c b/kernel/time/tick-sched.c
index 9cc20af58c76..f5ea98490ffa 100644
--- a/kernel/time/tick-sched.c
+++ b/kernel/time/tick-sched.c
@@ -387,20 +388,14 @@ void __init tick_nohz_init(void)
* NO HZ enabled ?
-static int tick_nohz_enabled __read_mostly = 1;
+static bool tick_nohz_enabled __read_mostly = true;
unsigned long tick_nohz_active __read_mostly;
* Enable / Disable tickless mode

Just discovered this conflicts with a recent patch with

commit 46373a15f65fe862f31c19a484acdf551f2b442f
Author: Jean Delvare <jdelvare@xxxxxxx>
Date: Mon Jan 11 17:40:31 2016 +0100

time: nohz: Expose tick_nohz_enabled

kernel/time/tick-sched.c:390:6: error: conflicting types for âtick_nohz_enabledâ
bool tick_nohz_enabled __read_mostly = true;
In file included from kernel/time/tick-internal.h:5:0,
from kernel/time/tick-sched.c:30:
include/linux/tick.h:101:12: note: previous declaration of âtick_nohz_enabledâ was here
extern int tick_nohz_enabled;

Fixing the compilation error, it compiles and boots on arm64, however
it isn't detecting the write (with the lkdtm test). I'll continue
looking into what's preventing this.