Messages in this thread | | | From | Thomas Gleixner <> | Subject | Re: [patch V4 part 1 22/36] tracing: Provide lockdep less trace_hardirqs_on/off() variants | Date | Thu, 07 May 2020 20:52:18 +0200 |
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Andy Lutomirski <luto@kernel.org> writes:
> On Tue, May 5, 2020 at 7:13 AM Thomas Gleixner <tglx@linutronix.de> wrote: >> >> trace_hardirqs_on/off() is only partially safe vs. RCU idle. The tracer >> core itself is safe, but the resulting tracepoints can be utilized by >> e.g. BPF which is unsafe. >> >> Provide variants which do not contain the lockdep invocation so the lockdep >> and tracer invocations can be split at the call site and placed properly. >> >> The new variants also do not use rcuidle as they are going to be called >> from entry code after/before context tracking. > > I can't quite follow this. Are you saying that the new variants are > intended to be called by the entry code in a context where tracing is > acceptable and that the lockdep part will still be called in a context > where tracing is not acceptable?
Yes. Before RCU is reestablished and after. I'll rephrase.
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