copyin()/copyout() constraints ?

Luigi Rizzo rizzo at
Wed Jun 12 17:58:16 UTC 2013

is it possible to run copyin() or copyout() in one of these cases:
1. while holding a spinlock
2. while holding a regular mutex/lock
3. while holding a read lock (on an RWLOCK or RMLOCK)
4. while holding a write lock (on an RWLOCK or RMLOCK)

I suspect #1 is forbidden, but am a bit unclear for the
other cases.


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