Messages in this thread | | | Date | Fri, 8 Jul 2016 22:24:55 +0200 | From | Torsten Duwe <> | Subject | Re: [PATCH v2 1/2] arm64: implement FTRACE_WITH_REGS |
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On Fri, Jul 08, 2016 at 11:57:10AM -0400, Steven Rostedt wrote: > On Fri, 8 Jul 2016 10:48:24 -0500 > Josh Poimboeuf <jpoimboe@redhat.com> wrote: > > > > Here, with -fprolog-pad, it's already a nop, so no change is needed. > >
Yes, exactly.
> That's what I was thinking. But as I stated in another email (probably > in the air when you wrote this), the call to ftrace_modify_code() may be > completely circumvented by ftrace_make_nop() if the addr is MCOUNT_ADDR.
Only on the _first_ invocation. Later on, tracing can be switched on and off, and then the instructions need to be changed just like with fentry (or profile-kernel ;-)
Torsten
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