linux-kernel - [PATCH 01/58] sysrq: Remove sysrq_handler

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Date:   Fri, 13 Dec 2019 00:06:00 +0000
From:   Dmitry Safonov <dima@...sta.com>
To:     linux-kernel@...r.kernel.org
Cc:     Dmitry Safonov <0x7f454c46@...il.com>,
        Dmitry Safonov <dima@...sta.com>,
        Greg Kroah-Hartman <gregkh@...uxfoundation.org>,
        Jiri Slaby <jslaby@...e.com>,
        Vasiliy Khoruzhick <vasilykh@...sta.com>,
        linux-serial@...r.kernel.org
Subject: [PATCH 01/58] sysrq: Remove sysrq_handler_registered

sysrq_toggle_support() can be called in parallel, in return calling
input_(un)register_handler(), which fortunately is safe to call
in parallel and regardless of registered/unregistered status of
sysrq_handler.
Remove sysrq_handler_registered as it doesn't have any function there
and may confuse reader about possible race.

Signed-off-by: Dmitry Safonov <dima@...sta.com>
---
 drivers/tty/sysrq.c | 9 +--------
 1 file changed, 1 insertion(+), 8 deletions(-)

diff --git a/drivers/tty/sysrq.c b/drivers/tty/sysrq.c
index 573b2055173c..1d4f317a0e42 100644
--- a/drivers/tty/sysrq.c
+++ b/drivers/tty/sysrq.c
@@ -967,8 +967,6 @@ static struct input_handler sysrq_handler = {
 	.id_table	= sysrq_ids,
 };
 
-static bool sysrq_handler_registered;
-
 static inline void sysrq_register_handler(void)
 {
 	int error;
@@ -978,16 +976,11 @@ static inline void sysrq_register_handler(void)
 	error = input_register_handler(&sysrq_handler);
 	if (error)
 		pr_err("Failed to register input handler, error %d", error);
-	else
-		sysrq_handler_registered = true;
 }
 
 static inline void sysrq_unregister_handler(void)
 {
-	if (sysrq_handler_registered) {
-		input_unregister_handler(&sysrq_handler);
-		sysrq_handler_registered = false;
-	}
+	input_unregister_handler(&sysrq_handler);
 }
 
 static int sysrq_reset_seq_param_set(const char *buffer,
-- 
2.24.0