[232/272] Input: sysrq - ensure sysrq_enabled and __sysrq_enabled are consistent

Greg KH
2011-02-16T00:25:00Z

From: Andy Whitcroft <apw@canonical.com>

commit 8c6a98b22b750c9eb52653ba643faa17db8d3881 upstream.

Currently sysrq_enabled and __sysrq_enabled are initialised separately
and inconsistently, leading to sysrq being actually enabled by reported
as not enabled in sysfs. The first change to the sysfs configurable
synchronises these two:

static int __read_mostly sysrq_enabled = 1;
static int __sysrq_enabled;

Add a common define to carry the default for these preventing them becoming
out of sync again. Default this to 1 to mirror previous behaviour.

Signed-off-by: Andy Whitcroft <apw@canonical.com>
Signed-off-by: Dmitry Torokhov <dtor@mail.ru>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

---
drivers/tty/sysrq.c | 2 +-
include/linux/sysrq.h | 3 +++
kernel/sysctl.c | 3 ++-
3 files changed, 6 insertions(+), 2 deletions(-)

--- a/drivers/tty/sysrq.c
+++ b/drivers/tty/sysrq.c
@@ -46,7 +46,7 @@
#include <asm/irq_regs.h>

/* Whether we react on sysrq keys or just ignore them */
-static int __read_mostly sysrq_enabled = 1;
+static int __read_mostly sysrq_enabled = SYSRQ_DEFAULT_ENABLE;
static bool __read_mostly sysrq_always_enabled;

static bool sysrq_on(void)
--- a/include/linux/sysrq.h
+++ b/include/linux/sysrq.h
@@ -17,6 +17,9 @@
#include <linux/errno.h>
#include <linux/types.h>

+/* Enable/disable SYSRQ support by default (0==no, 1==yes). */
+#define SYSRQ_DEFAULT_ENABLE 1
+
/* Possible values of bitmask for enabling sysrq functions */
/* 0x0001 is reserved for enable everything */
#define SYSRQ_ENABLE_LOG 0x0002
--- a/kernel/sysctl.c
+++ b/kernel/sysctl.c
@@ -169,7 +169,8 @@ static int proc_taint(struct ctl_table *
#endif

#ifdef CONFIG_MAGIC_SYSRQ
-static int __sysrq_enabled; /* Note: sysrq code ises it's own private copy */
+/* Note: sysrq code uses it's own private copy */
+static int __sysrq_enabled = SYSRQ_DEFAULT_ENABLE;

static int sysrq_sysctl_handler(ctl_table *table, int write,
void __user *buffer, size_t *lenp,