| Date | Wed, 26 Oct 2022 10:20:37 +0200 | From | Petr Mladek <> | Subject | Re: [PATCH printk v2 31/38] printk: register_console: use srcu console list iterator |
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On Wed 2022-10-19 17:01:53, John Ogness wrote: > Use srcu console list iteration for console list traversal. Now > the traversal at the beginning of register_console() is safe. > > Signed-off-by: John Ogness <john.ogness@linutronix.de>
Reviewed-by: Petr Mladek <pmladek@suse.com>
That said, I think that we could omit this patch. It does not harm. It prevents a crash when iterating the list but it is only small part of the races here.
For example, it sets "realcon_enabled" but the list might change before the value is used. Also the later hlist_empty(&console_list) and !console_first->device checks are not secure against each other.
The real solution is the introduction of console_list_lock in 33th patch. That patch removes the rcu read lock. From this POV, this patch is just unnecessary churn.
Best Regards, Petr
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