Commit d368967c authored by Linus Torvalds's avatar Linus Torvalds
Browse files

Merge tag 'printk-for-6.2-rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/printk/linux 

Pull printk fixes from Petr Mladek:

 - Prevent a potential deadlock when configuring kgdb console

 - Fix a kernel doc warning

* tag 'printk-for-6.2-rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/printk/linux:
  kernel/printk/printk.c: Fix W=1 kernel-doc warning
  tty: serial: kgdboc: fix mutex locking order for configure_kgdboc()
parents a03df4ec 21493c6e

drivers/tty/serial/kgdboc.c

+5 −15
Original line number Diff line number Diff line
@@ -171,6 +171,7 @@ static int configure_kgdboc(void) 
	int err = -ENODEV;

	char *cptr = config;

	struct console *cons;

	int cookie;



	if (!strlen(config) || isspace(config[0])) {

		err = 0;
@@ -189,20 +190,9 @@ static int configure_kgdboc(void) 
	if (kgdboc_register_kbd(&cptr))

		goto do_register;



	/*

	 * tty_find_polling_driver() can call uart_set_options()

	 * (via poll_init) to configure the uart. Take the console_list_lock

	 * in order to synchronize against register_console(), which can also

	 * configure the uart via uart_set_options(). This also allows safe

	 * traversal of the console list.

	 */

	console_list_lock();



	p = tty_find_polling_driver(cptr, &tty_line);

	if (!p) {

		console_list_unlock();

	if (!p)

		goto noconfig;

	}



	/*

	 * Take console_lock to serialize device() callback with
@@ -211,7 +201,8 @@ static int configure_kgdboc(void) 
	 */

	console_lock();



	for_each_console(cons) {

	cookie = console_srcu_read_lock();

	for_each_console_srcu(cons) {

		int idx;

		if (cons->device && cons->device(cons, &idx) == p &&

		    idx == tty_line) {
@@ -219,11 +210,10 @@ static int configure_kgdboc(void) 
			break;

		}

	}

	console_srcu_read_unlock(cookie);



	console_unlock();



	console_list_unlock();



	kgdb_tty_driver = p;

	kgdb_tty_line = tty_line;

drivers/tty/serial/serial_core.c

+5 −0
Original line number Diff line number Diff line
@@ -2212,6 +2212,9 @@ EXPORT_SYMBOL_GPL(uart_parse_options); 
 * @parity: parity character - 'n' (none), 'o' (odd), 'e' (even)

 * @bits: number of data bits

 * @flow: flow control character - 'r' (rts)

 *

 * Locking: Caller must hold console_list_lock in order to serialize

 * early initialization of the serial-console lock.

 */

int

uart_set_options(struct uart_port *port, struct console *co,
@@ -2619,7 +2622,9 @@ static int uart_poll_init(struct tty_driver *driver, int line, char *options) 


	if (!ret && options) {

		uart_parse_options(options, &baud, &parity, &bits, &flow);

		console_list_lock();

		ret = uart_set_options(port, NULL, baud, parity, bits, flow);

		console_list_unlock();

	}

out:

	mutex_unlock(&tport->mutex);

kernel/printk/printk.c

+2 −0
Original line number Diff line number Diff line
@@ -123,6 +123,7 @@ bool console_srcu_read_lock_is_held(void) 
{

	return srcu_read_lock_held(&console_srcu);

}

EXPORT_SYMBOL(console_srcu_read_lock_is_held);

#endif



enum devkmsg_log_bits {
@@ -1891,6 +1892,7 @@ static void console_lock_spinning_enable(void) 
/**

 * console_lock_spinning_disable_and_check - mark end of code where another

 *	thread was able to busy wait and check if there is a waiter

 * @cookie: cookie returned from console_srcu_read_lock()

 *

 * This is called at the end of the section where spinning is allowed.

 * It has two functions. First, it is a signal that it is no longer