On Fri, 20 Apr 2018 16:57:20 +0200
Petr Mladek <pmladek@xxxxxxxx> wrote:
> No, call_console_drivers() is done with interrupts disabled:
>
> console_lock_spinning_enable();
>
> stop_critical_timings(); /* don't trace print latency */
> ----> call_console_drivers(ext_text, ext_len, text, len);
> start_critical_timings();
>
> if (console_lock_spinning_disable_and_check()) {
> ----> printk_safe_exit_irqrestore(flags);
> goto out;
> }
>
> ----> printk_safe_exit_irqrestore(flags);
>
> They were called with interrupts disabled for ages, long before
> printk_safe. In fact, it was all the time in the git kernel history.
>
> Therefore only NMIs are in the game. And they should be solved
> by the above change.
>
Really?
console_trylock_spinning(); /* console_owner now equals current */
console_unlock() {
---> take interrupt here:
vprintk() {
vprintk_func() {
if (console_owner == current && !__ratelimit(&ratelimit_console))
[ RATE LIMIT HERE!!!! ]
for (;;) {
printk_safe_enter_irqsave(flags);
-- Steve
