Messages in this thread |  | | From | Namhyung Kim <> | Subject | Re: [PATCHSET 00/13] tracing/uprobes: Add support for more fetch methods (v6) | Date | Wed, 06 Nov 2013 17:57:24 +0900 |
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On Tue, 5 Nov 2013 20:24:01 +0100, Oleg Nesterov wrote: > On 11/05, Oleg Nesterov wrote: >> >> As for "-= tu->offset"... Can't we avoid it? User-space needs to calculate >> the "@" argument anyway, why it can't also substruct this offset? >> >> Or perhaps we can change parse_probe_arg("@") to update "param" ? Yes, >> in this case it needs another argument, not sure... > > Or, > >> + if (is_ret_probe(tu)) { >> + saved_ip = instruction_pointer(regs); >> + instruction_pointer_set(func); >> + } >> store_trace_args(...); >> + if (is_ret_probe(tu)) >> + instruction_pointer_set(saved_ip); > > we can put "-= tu->offset" here.
I don't think I get the point.
> > Or. Perhaps we can leave "case '@'" in parse_probe_arg() and > FETCH_MTD_memory alone. You seem to agree that "absolute address" > can be useful anyway.
Yes, but it's only meaningful to process-wide tracing sessions IMHO.
> > Instead, perhaps we can add FETCH_MTD_memory_do_fancy_addr_translation, > and, say, the new "case '*'" in parse_probe_arg() should add all the > neccessary info as f->data (like, say, FETCH_MTD_symbol).
Could you elaborate this more?
> > But, just in case, I do not have a strong opinion. Just I think it > is better to discuss every choice we have.
Okay. I really appreciate your reviews.
Thanks, Namhyung
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