Commit 2c6b4b70 authored by John Ogness's avatar John Ogness Committed by Petr Mladek
Browse files

netconsole: avoid CON_ENABLED misuse to track registration 



The CON_ENABLED flag is being misused to track whether or not the
extended console should be or has been registered. Instead use
a local variable to decide if the extended console should be
registered and console_is_registered() to determine if it has
been registered.

Also add a check in cleanup_netconsole() to only unregister the
extended console if it has been registered.

Signed-off-by: default avatarJohn Ogness <john.ogness@linutronix.de>
Reviewed-by: default avatarPetr Mladek <pmladek@suse.com>
Signed-off-by: default avatarPetr Mladek <pmladek@suse.com>
Link: https://lore.kernel.org/r/20221116162152.193147-32-john.ogness@linutronix.de
parent 9490b22a

drivers/net/netconsole.c

+11 −10
Original line number Diff line number Diff line
@@ -332,10 +332,8 @@ static ssize_t enabled_store(struct config_item *item, 
	}



	if (enabled) {	/* true */

		if (nt->extended && !(netconsole_ext.flags & CON_ENABLED)) {

			netconsole_ext.flags |= CON_ENABLED;

		if (nt->extended && !console_is_registered(&netconsole_ext))

			register_console(&netconsole_ext);

		}



		/*

		 * Skip netpoll_parse_options() -- all the attributes are
@@ -869,7 +867,7 @@ static void write_msg(struct console *con, const char *msg, unsigned int len) 


static struct console netconsole_ext = {

	.name	= "netcon_ext",

	.flags	= CON_EXTENDED,	/* starts disabled, registered on first use */

	.flags	= CON_ENABLED | CON_EXTENDED,

	.write	= write_ext_msg,

};
@@ -883,6 +881,7 @@ static int __init init_netconsole(void) 
{

	int err;

	struct netconsole_target *nt, *tmp;

	bool extended = false;

	unsigned long flags;

	char *target_config;

	char *input = config;
@@ -895,11 +894,12 @@ static int __init init_netconsole(void) 
				goto fail;

			}

			/* Dump existing printks when we register */

			if (nt->extended)

				netconsole_ext.flags |= CON_PRINTBUFFER |

							CON_ENABLED;

			else

			if (nt->extended) {

				extended = true;

				netconsole_ext.flags |= CON_PRINTBUFFER;

			} else {

				netconsole.flags |= CON_PRINTBUFFER;

			}



			spin_lock_irqsave(&target_list_lock, flags);

			list_add(&nt->list, &target_list);
@@ -915,7 +915,7 @@ static int __init init_netconsole(void) 
	if (err)

		goto undonotifier;



	if (netconsole_ext.flags & CON_ENABLED)

	if (extended)

		register_console(&netconsole_ext);

	register_console(&netconsole);

	pr_info("network logging started\n");
@@ -945,6 +945,7 @@ static void __exit cleanup_netconsole(void) 
{

	struct netconsole_target *nt, *tmp;



	if (console_is_registered(&netconsole_ext))

		unregister_console(&netconsole_ext);

	unregister_console(&netconsole);

	dynamic_netconsole_exit();