Messages in this thread |  | | Date | Fri, 8 Nov 2013 17:52:33 +0100 | From | Oleg Nesterov <> | Subject | Re: [PATCHSET 00/13] tracing/uprobes: Add support for more fetch methods (v6) |
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Hi Namhyung,
sorry for delay.
On 11/07, Namhyung Kim 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? > >> > >> Hmm.. it makes sense too. :) > > > > I am no longer sure ;) > > > > This way the "@" argument will look more confusing, it will depend on the > > address/offset of the probed insn. But again, I do not know, this is up > > to you. > > That said, I'd prefer the original "-= -tu->offset" approach. It'll > make debugging easier IMHO.
I do not really mind, and probably you are right. Actually it seems that I was confused, if user-space does "-= -tu->offset" itself then the "@" argument will look more consistent (contrary to what I said above).
In any case we should make the calculation of "@" argument (in user space) as simple/clear as possible, it is very easy to add the additional hacks in kernel if necessary.
And this is very (if not most) important part, we can change the kernel later, but it is not easy to change the already working semantics, so I'd like to know what other reviewers think.
Oleg.
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