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printk: remove @console_locked 

The static global variable @console_locked is used to help debug
VT code to make sure that certain code paths are running with
the console_lock held. However, this information is also available
with the static global variable @console_kthreads_blocked (for
locking via console_lock()), and the static global variable
@console_kthreads_active (for locking via console_trylock()).

Remove @console_locked and update is_console_locked() to use the
alternative variables.

Signed-off-by: John Ogness <john.ogness@linutronix.de>
Reviewed-by: Petr Mladek <pmladek@suse.com>
Signed-off-by: Petr Mladek <pmladek@suse.com>
Link: https://lore.kernel.org/r/20220421212250.565456-16-john.ogness@linutronix.de
This commit is contained in:
John Ogness 2022-04-21 23:28:50 +02:06 committed by Petr Mladek
parent 8e27473211
commit ab406816fc
1 changed files with 14 additions and 15 deletions
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29
kernel/printk/printk.c
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@ -340,15 +340,7 @@ static void console_kthreads_unblock(void)
console_kthreads_blocked = false;
}
/*
* This is used for debugging the mess that is the VT code by
* keeping track if we have the console semaphore held. It's
* definitely not the perfect debug tool (we don't know if _WE_
* hold it and are racing, but it helps tracking those weird code
* paths in the console code where we end up in places I want
* locked without the console semaphore held).
*/
static int console_locked, console_suspended;
static int console_suspended;
/*
* Array of consoles built from command line options (console=)
@ -2719,7 +2711,6 @@ void console_lock(void)
if (console_suspended)
return;
console_kthreads_block();
console_locked = 1;
console_may_schedule = 1;
}
EXPORT_SYMBOL(console_lock);
@ -2744,15 +2735,26 @@ int console_trylock(void)
up_console_sem();
return 0;
}
console_locked = 1;
console_may_schedule = 0;
return 1;
}
EXPORT_SYMBOL(console_trylock);
/*
* This is used to help to make sure that certain paths within the VT code are
* running with the console lock held. It is definitely not the perfect debug
* tool (it is not known if the VT code is the task holding the console lock),
* but it helps tracking those weird code paths in the console code such as
* when the console is suspended: where the console is not locked but no
* console printing may occur.
*
* Note: This returns true when the console is suspended but is not locked.
* This is intentional because the VT code must consider that situation
* the same as if the console was locked.
*/
int is_console_locked(void)
{
return (console_locked || atomic_read(&console_kthreads_active));
return (console_kthreads_blocked || atomic_read(&console_kthreads_active));
}
EXPORT_SYMBOL(is_console_locked);
@ -2808,8 +2810,6 @@ static inline bool console_is_usable(struct console *con)
static void __console_unlock(void)
{
console_locked = 0;
/*
* Depending on whether console_lock() or console_trylock() was used,
* appropriately allow the kthread printers to continue.
@ -3127,7 +3127,6 @@ void console_unblank(void)
} else
console_lock();
console_locked = 1;
console_may_schedule = 0;
for_each_console(c)
if ((c->flags & CON_ENABLED) && c->unblank)