linux-kernel - [PATCH v5 6/7] console: Don't notify user space when unregister non-listed console

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Message-Id: <20200203133130.11591-6-andriy.shevchenko@linux.intel.com>
Date:   Mon,  3 Feb 2020 15:31:29 +0200
From:   Andy Shevchenko <andriy.shevchenko@...ux.intel.com>
To:     Petr Mladek <pmladek@...e.com>,
        Sergey Senozhatsky <sergey.senozhatsky@...il.com>,
        linux-kernel@...r.kernel.org, Steven Rostedt <rostedt@...dmis.org>
Cc:     Andy Shevchenko <andriy.shevchenko@...ux.intel.com>,
        Sergey Senozhatsky <sergey.senozhatsky.work@...il.com>
Subject: [PATCH v5 6/7] console: Don't notify user space when unregister non-listed console

If console is not on the list then there is nothing for us to do
and sysfs notify is pointless.

Note, that nr_ext_console_drivers is being changed only for listed consoles.

Suggested-by: Sergey Senozhatsky <sergey.senozhatsky.work@...il.com>
Signed-off-by: Andy Shevchenko <andriy.shevchenko@...ux.intel.com>
---
v5: new patch

 kernel/printk/printk.c | 12 +++++++++++-
 1 file changed, 11 insertions(+), 1 deletion(-)

diff --git a/kernel/printk/printk.c b/kernel/printk/printk.c
index 5fdae891a4cd..abd9b92ae0e3 100644
--- a/kernel/printk/printk.c
+++ b/kernel/printk/printk.c
@@ -2843,7 +2843,10 @@ int unregister_console(struct console *console)
 		}
 	}
 
-	if (!res && (console->flags & CON_EXTENDED))
+	if (res)
+		goto out_disable_unlock;
+
+	if (console->flags & CON_EXTENDED)
 		nr_ext_console_drivers--;
 
 	/*
@@ -2856,6 +2859,13 @@ int unregister_console(struct console *console)
 	console->flags &= ~CON_ENABLED;
 	console_unlock();
 	console_sysfs_notify();
+
+	return res;
+
+out_disable_unlock:
+	console->flags &= ~CON_ENABLED;
+	console_unlock();
+
 	return res;
 }
 EXPORT_SYMBOL(unregister_console);
-- 
2.24.1