| From | John Ogness <> | Subject | [PATCH printk v3 08/40] printk: use console_is_enabled() | Date | Mon, 7 Nov 2022 15:22:06 +0106 |
| |
Replace (console->flags & CON_ENABLED) usage with console_is_enabled() if it involves a data race. Otherwise add comments mentioning why the wrapper is not used.
Note that this is a preparatory change for when console_lock no longer provides synchronization for console->flags.
Signed-off-by: John Ogness <john.ogness@linutronix.de> --- kernel/printk/printk.c | 9 ++++++--- 1 file changed, 6 insertions(+), 3 deletions(-)
diff --git a/kernel/printk/printk.c b/kernel/printk/printk.c index 79811984da34..f243bb56a3ba 100644 --- a/kernel/printk/printk.c +++ b/kernel/printk/printk.c @@ -2660,7 +2660,7 @@ static bool abandon_console_lock_in_panic(void) */ static inline bool console_is_usable(struct console *con) { - if (!(con->flags & CON_ENABLED)) + if (!console_is_enabled(con)) return false; if (!con->write) @@ -2946,7 +2946,7 @@ void console_unblank(void) console_locked = 1; console_may_schedule = 0; for_each_console(c) - if ((c->flags & CON_ENABLED) && c->unblank) + if (console_is_enabled(c) && c->unblank) c->unblank(); console_unlock(); @@ -3104,8 +3104,11 @@ static int try_enable_preferred_console(struct console *newcon, * Some consoles, such as pstore and netconsole, can be enabled even * without matching. Accept the pre-enabled consoles only when match() * and setup() had a chance to be called. + * + * Note that reading @flags is race-free because the console is not + * yet added to the console list. */ - if (newcon->flags & CON_ENABLED && c->user_specified == user_specified) + if ((newcon->flags & CON_ENABLED) && (c->user_specified == user_specified)) return 0; return -ENOENT; -- 2.30.2
|