Re: [PATCH v10 2/4] trace/objtrace: Get the value of the object

[Jeff Xie <xiehuan09@gmail.com>]

Hi Masami,

On Sun, May 22, 2022 at 10:22 PM Masami Hiramatsu <mhiramat@kernel.org> wrote:
>
> Hi Jeff,
>
> On Fri, 13 May 2022 01:00:06 +0800
> Jeff Xie <xiehuan09@gmail.com> wrote:
>
> [...]
> > @@ -175,9 +271,27 @@ trace_object_trigger(struct event_trigger_data *data,
> >
> >       field = obj_data->field;
> >       memcpy(&obj, rec + field->offset, sizeof(obj));
> > -     set_trace_object(obj, tr);
> > +     /* set the offset from the special object and the type size of the value*/
> > +     set_trace_object(obj, obj_data->obj_offset,
> > +                     obj_data->obj_value_type_size, tr);
> >  }
> >
> > +static const struct objtrace_fetch_type objtrace_fetch_types[] = {
> > +     {"u8", 1},
> > +     {"s8", 1},
> > +     {"x8", 1},
> > +     {"u16", 2},
> > +     {"s16", 2},
> > +     {"x16", 2},
> > +     {"u32", 4},
> > +     {"s32", 4},
> > +     {"x32", 4},
> > +     {"u64", 8},
> > +     {"s64", 8},
> > +     {"x64", 8},
>
> Hmm, as far as I can see, you don't distinguish the prefix 'u','s','x'.
> If so, please support only 'x' at this moment. kprobe events supports
> those types, and it distinguishes the types when printing the logged
> data. E.g. 's16' shows '-1' for 0xffff, but 'x16' shows '0xffff'.
> You can add another patch to support such different types afterwards.

Thanks, I will add another patch to support it .

> > +     {}
>
> If this array is null terminated, please explictly do that, like
>
>         {NULL, 0},
>
> for readability.

Thank you for your reminder.

> Thank you,
>
> --
> Masami Hiramatsu (Google) <mhiramat@kernel.org>

Thanks,
JeffXie