diff mbox series

[printk,v4,34/39] tty: serial: kgdboc: use srcu console list iterator

Message ID 20221114162932.141883-35-john.ogness@linutronix.de
State New
Headers
Series reduce console_lock scope |

Commit Message

John Ogness Nov. 14, 2022, 4:29 p.m. UTC 
  Use srcu console list iteration for safe console list traversal.
Note that this is a preparatory change for when console_lock no
longer provides synchronization for the console list.

Signed-off-by: John Ogness <john.ogness@linutronix.de>
---
 drivers/tty/serial/kgdboc.c | 10 ++++++++--
 1 file changed, 8 insertions(+), 2 deletions(-)

Comments

Petr Mladek Nov. 15, 2022, 3:17 p.m. UTC | #1 
On Mon 2022-11-14 17:35:27, John Ogness wrote:
> Use srcu console list iteration for safe console list traversal.
> Note that this is a preparatory change for when console_lock no
> longer provides synchronization for the console list.
> 
> Signed-off-by: John Ogness <john.ogness@linutronix.de>

Reviewed-by: Petr Mladek <pmladek@suse.com>

Best Regards,
Petr
diff mbox series

Patch

diff --git a/drivers/tty/serial/kgdboc.c b/drivers/tty/serial/kgdboc.c
index 5be381003e58..c6df9ef34099 100644
--- a/drivers/tty/serial/kgdboc.c
+++ b/drivers/tty/serial/kgdboc.c
@@ -451,6 +451,7 @@  static void kgdboc_earlycon_pre_exp_handler(void)
 {
 	struct console *con;
 	static bool already_warned;
+	int cookie;
 
 	if (already_warned)
 		return;
@@ -463,9 +464,14 @@  static void kgdboc_earlycon_pre_exp_handler(void)
 	 * serial drivers might be OK with this, print a warning once per
 	 * boot if we detect this case.
 	 */
-	for_each_console(con)
+	cookie = console_srcu_read_lock();
+	for_each_console_srcu(con) {
 		if (con == kgdboc_earlycon_io_ops.cons)
-			return;
+			break;
+	}
+	console_srcu_read_unlock(cookie);
+	if (con)
+		return;
 
 	already_warned = true;
 	pr_warn("kgdboc_earlycon is still using bootconsole\n");