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tty: serial: kgdboc: use console_list_lock for list traversal

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configure_kgdboc() uses the console_lock for console list iteration. Use
the console_list_lock instead because list synchronization responsibility
will be removed from the console_lock in a later change.

The SRCU iterator could have been used here, but a later change will
relocate the locking of the console_list_lock to also provide
synchronization against register_console().

Note, the console_lock is still needed to serialize the device()
callback with other console operations.

Signed-off-by: John Ogness <john.ogness@linutronix.de>
Reviewed-by: Petr Mladek <pmladek@suse.com>
Reviewed-by: Douglas Anderson <dianders@chromium.org>
Signed-off-by: Petr Mladek <pmladek@suse.com>
Link: https://lore.kernel.org/r/20221116162152.193147-37-john.ogness@linutronix.de
This commit is contained in:
John Ogness 2022-11-16 17:27:48 +01:06 committed by Petr Mladek
parent 7e537af997
commit 6685744369
1 changed files with 12 additions and 0 deletions
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12
drivers/tty/serial/kgdboc.c
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@ -193,7 +193,16 @@ static int configure_kgdboc(void)
if (!p)
goto noconfig;
/* For safe traversal of the console list. */
console_list_lock();
/*
* Take console_lock to serialize device() callback with
* other console operations. For example, fg_console is
* modified under console_lock when switching vt.
*/
console_lock();
for_each_console(cons) {
int idx;
if (cons->device && cons->device(cons, &idx) == p &&
@ -202,8 +211,11 @@ static int configure_kgdboc(void)
break;
}
}
console_unlock();
console_list_unlock();
kgdb_tty_driver = p;
kgdb_tty_line = tty_line;