linux-kernel - [PATCH printk-rework 14/14] printk: console: remove unnecessary safe buffer usage

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Date:   Thu, 18 Feb 2021 09:18:17 +0100
From:   John Ogness <john.ogness@...utronix.de>
To:     Petr Mladek <pmladek@...e.com>
Cc:     Sergey Senozhatsky <sergey.senozhatsky.work@...il.com>,
        Sergey Senozhatsky <sergey.senozhatsky@...il.com>,
        Steven Rostedt <rostedt@...dmis.org>,
        Thomas Gleixner <tglx@...utronix.de>,
        linux-kernel@...r.kernel.org
Subject: [PATCH printk-rework 14/14] printk: console: remove unnecessary safe buffer usage

Upon registering a console, safe buffers are activated when setting
up the sequence number to replay the log. However, these are already
protected by @console_sem and @syslog_lock. Remove the unnecessary
safe buffer usage.

Signed-off-by: John Ogness <john.ogness@...utronix.de>
---
 kernel/printk/printk.c | 10 +++-------
 1 file changed, 3 insertions(+), 7 deletions(-)

diff --git a/kernel/printk/printk.c b/kernel/printk/printk.c
index 23d525e885e7..78eee6c553a5 100644
--- a/kernel/printk/printk.c
+++ b/kernel/printk/printk.c
@@ -2961,9 +2961,7 @@ void register_console(struct console *newcon)
 		/*
 		 * console_unlock(); will print out the buffered messages
 		 * for us.
-		 */
-		printk_safe_enter_irqsave(flags);
-		/*
+		 *
 		 * We're about to replay the log buffer.  Only do this to the
 		 * just-registered console to avoid excessive message spam to
 		 * the already-registered consoles.
@@ -2976,11 +2974,9 @@ void register_console(struct console *newcon)
 		exclusive_console_stop_seq = console_seq;
 
 		/* Get a consistent copy of @syslog_seq. */
-		raw_spin_lock(&syslog_lock);
+		raw_spin_lock_irqsave(&syslog_lock, flags);
 		console_seq = syslog_seq;
-		raw_spin_unlock(&syslog_lock);
-
-		printk_safe_exit_irqrestore(flags);
+		raw_spin_unlock_irqrestore(&syslog_lock, flags);
 	}
 	console_unlock();
 	console_sysfs_notify();
-- 
2.20.1