Hi Eric, On Tue, Jul 19, 2022 at 9:26 PM Eric W. Biederman <ebiederm@xxxxxxxxxxxx> wrote: > > "Jason A. Donenfeld" <Jason@xxxxxxxxx> writes: > > > There are two deadlock scenarios that need addressing, which cause > > problems when the computer goes to sleep, the interface is set down, and > > hwrng_unregister() is called. When the deadlock is hit, sleep is delayed > > for tens of seconds, causing it to fail. These scenarios are: > > > > 1) The hwrng kthread can't be stopped while it's sleeping, because it > > uses msleep_interruptible() instead of schedule_timeout_interruptible(). > > The fix is a simple moving to the correct function. At the same time, > > we should cleanup a common and useless dmesg splat in the same area. > > > > 2) A normal user thread can't be interrupted by hwrng_unregister() while > > it's sleeping, because hwrng_unregister() is called from elsewhere. > > The solution here is to keep track of which thread is currently > > reading, and asleep, and signal that thread when it's time to > > unregister. There's a bit of book keeping required to prevent > > lifetime issues on current. > > Is there any chance you can name the new function > wake_up_task_interruptible instead of wake_up_process_interruptible. > > The name wake_up_process is wrong now, it does not wake up all threads > of a process. The name dates back to before linux supported multiple > threads in a process, so it is grandfathered in until someone gets > changes it. But please let's not have a new function with a incorrect > and confusing name. No problem. v+1 incoming. Jason
