sched/sem_waitirq: Move kmm_map() call to sem_wait() #366
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The kernel mapping should be performed in sem_wait (thread level) as virtual memory mappings cannot be added from interrupt, at least for now.
The reason?
kmm_map() depends on mm_map_add(), which in turn uses a mutex for mutual exclusion. Using mutexes from interrupt level is not permitted.
Mapping tcb->waitobj into kernel virtual memory directly in sem_wait() makes sense, since accessing tcb->waitobj via a user virtual address can lead to unexpected results (the wrong mappings can be in place).