Messages in this thread | | | Date | Tue, 12 Mar 2019 11:51:28 +0900 | From | Sergey Senozhatsky <> | Subject | Re: [RFC PATCH v1 19/25] printk: introduce emergency messages |
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On (03/11/19 13:04), John Ogness wrote: > > Great catch! > > Yes, thanks! > > > I think that it is doable to guard the list using RCU. > > I think it would be enough to take the prb_cpulock when modifying the > console linked list. That will keep printk_emergency() out until the > list has been updated. (registering/unregistering consoles is not > something that happens often.)
console_sem can be a bit more than just registering/unregistering. Especially when it comes to VT, fbcon and ioctls.
$ git grep console_lock drivers/tty/ | wc -l 82
$ git grep console_lock drivers/video/fbdev/ | wc -l 80
-ss
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