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@gmail.com>
Link: http://lkml.kernel.org/r/20200203133130.11591-6-andriy.shevchenko@linux.intel.com
To: linux-kernel@vger.kernel.org
To: Steven Rostedt <rostedt@goodmis.org>
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Reviewed-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
Reviewed-by: Petr Mladek <pmladek@suse.com>
Signed-off-by: Petr Mladek <pmladek@suse.com>

diff --git a/kernel/printk/printk.c b/kernel/printk/printk.c
index 61d188f4c672d52bbbf3d7a964dc1aa6c5dac79c..f435a17ef988260e1eb630b8bd3dde844b4027b9 100644 (file)
--- a/kernel/printk/printk.c
+++ b/kernel/printk/printk.c
@@ -2836,7 +2836,10 @@ 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--;
 
        /*
@@ -2849,6 +2852,13 @@ 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);