Messages in this thread | | | Date | Tue, 18 Feb 2020 11:35:03 -0500 | From | Steven Rostedt <> | Subject | Re: [PATCH v2 3/9] rcu,tracing: Create trace_rcu_{enter,exit}() |
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On Tue, 18 Feb 2020 08:12:31 -0800 "Paul E. McKenney" <paulmck@kernel.org> wrote:
> Would it work to describe the general problem, then give x86 details > as a specific example, as follows? > > /* > * On some architectures, certain exceptions prohibit use of kprobes until > * the exception code path reaches a certain point. For example, on x86 all > * functions called by do_int3() must be marked NOKPROBE. However, once > * kprobe_int3_handler() is called, kprobing is permitted. Specifically, > * ist_enter() is called in do_int3() before kprobe_int3_handle(). > * Furthermore, ist_enter() calls rcu_nmi_enter(), which means that > * rcu_nmi_enter() must be marked NOKRPOBE. > */ > > That way, I don't feel like I need to update the commment each time > a new architecture adds this capability. ;-)
I don't think this is going to be an issue for other archs, as they don't have an IST.
-- Steve
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