Change Details

Calling userret() from fork_return() misses the first return to userspace of the "init" (PID 1) process. The latter is indeed created by fork1() followed by a call to cpu_fork_kthread_handler() call that replaces fork_return() by start_init() as the function to execute after fork. A new process' initial return to userspace in the end always happens through returning from fork_exit(), so move userret() there instead to fix the omission.

Calling userret() from fork_return() misses the first return to userspace of the "init" (PID 1) process. The latter is indeed created by fork1() followed by a call to cpu_fork_kthread_handler() call that replaces fork_return() by start_init() as the function to execute after fork. A new process' initial return to userspace in the end always happens through returning from fork_exit(), so move userret() there instead to fix the omission. This problem was discovered as part of a revamp of scheduling priorities that lead to experimenting with asserting and sometimes resetting priorities in sched_userret(), in the course of which the author stumbled on panics being triggered only in init() or only in other processes, depending on the modifications to sched_userret(). This change currently has no practical effect but will have some in the near future. MFC after: 2 weeks Sponsored by: The FreeBSD Foundation

Calling userret() from fork_return() misses the first return to userspace of the "init" (PID 1) process. The latter is indeed created by fork1() followed by a call to cpu_fork_kthread_handler() call that replaces fork_return() by start_init() as the function to execute after fork. A new process' initial return to userspace in the end always happens through returning from fork_exit(), so move userret() there instead to fix the omission. This problem was discovered as part of a revamp of scheduling priorities that lead to experimenting with asserting and sometimes resetting priorities in sched_userret(), in the course of which the author stumbled on panics being triggered only in init() or only in other processes, depending on the modifications to sched_userret(). This change currently has no practical effect but will have some in the near future. MFC after: 2 weeks Sponsored by: The FreeBSD Foundation