Re: [RFC PATCH] tracing: Fix syscall tracepoint use-after-free

[Jordan Rife]

I assume this patch isn't meant to fix the related issues with freeing
BPF programs/links with call_rcu?

On the BPF side I think there needs to be some smarter handling of
when to use call_rcu or call_rcu_tasks_trace to free links/programs
based on whether or not the program type can be executed in this
context. Right now call_rcu_tasks_trace is used if the program is
sleepable, but that isn't necessarily the case here. Off the top of my
head this would be BPF_PROG_TYPE_RAW_TRACEPOINT and
BPF_PROG_TYPE_RAW_TRACEPOINT_WRITABLE, but may extend to
BPF_PROG_TYPE_TRACEPOINT? I'll let some of the BPF folks chime in
here, as I'm not entirely sure.

-Jordan