Date: Wed, 7 Aug 2019 17:11:34 +0800 From: Liang Zhuo <brightiup.zhuo@gmail.com> To: freebsd-hackers@freebsd.org Subject: Force kernel epoch calls Message-ID: <CACqxGXWZVeFK8kUpRaPtArnvZ5GD6CR44LJBHLCeP-KPJdSPNg@mail.gmail.com>
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Hi list, I have a problem with *epoch* while I am trying to write an exploit of a FreeBSD kernel bug. Specifically, many schedules are managed by epoch system, like *if_d\* *estroy()* which destroys a *struct ifnet* object, and *in_pcbfree_**defered()* which destroys a *struct inpcb* object. My question is that these schedules will only be called just before the process exits by *epoch_call_task() *as follow: fork_exit() -> gtaskqueue_thread_loop() -> gtaskqueue_run_locked() -> epoch_call_task() -> if_destroy()/in_pcbfree_defered() But I need to control the time of freeing of those objects as better as synchronization. Do do I have any methods to force these calls in epoch system to be called in userspace? Thanks, Brightiup
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