Messages in this thread | | | Subject | Re: [PATCH 1/9] LoongArch/ftrace: Add basic support | From | Jinyang He <> | Date | Sat, 20 Aug 2022 11:16:03 +0800 |
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On 08/20/2022 09:52 AM, Steven Rostedt wrote:
> On Sat, 20 Aug 2022 09:38:21 +0800 > Jinyang He <hejinyang@loongson.cn> wrote: > >> I think we have implemented CONFIG_FTRACE_WITH_ARGS in dynamic ftrace >> in the [Patch3/9]. > Sorry, I must have missed it. And there is still something left to do, Qing will do that.
> >> But, for non dynamic ftrace, it is hardly to >> implement it. Because the LoongArch compiler gcc treats mount as a > Don't bother implementing it for non-dynamic. I would just add a: > > config HAVE_FTRACE_WITH_ARGS if DYNAMIC_FTRACE > > and be done with it. Yes, it is clear.
> >> really call, like 'call _mcount(__builtin_return_address(0))'. That >> means, they decrease stack, save args to callee saved regs and may >> do some optimization before calling mcount. It is difficult to find the >> original args and apply changes from tracers. > Right, there's no point in implementing it for non dynamic. Like I said, > non-dynamic is just a stepping stone for getting dynamic working. Once you > have dynamic working, it's up to you to throw out the non-dynamic. It's not > useful for anything other than porting to a new architecture or for > academic purposes. > Thanks for your detail answers. Jinyang
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