Re: [PATCH v3 0/5] tracing/probes: uaccess: Add support user-space access

[Masami Hiramatsu]

On Wed, 27 Feb 2019 14:32:41 -0800
Alexei Starovoitov <alexei.starovoitov@xxxxxxxxx> wrote:

> On Wed, Feb 27, 2019 at 11:42:15PM +0900, Masami Hiramatsu wrote:
> > 
> > For perf-probe, we can add some attribute for each argument
> > which indicate that the variable in user space. But still
> > we can not decide it automatically by DWARF since __user attribute
> > is not transrated to DWARF attribute.
> 
> clang has partial support for __attribute__((noderef, address_space(1)))
> We'll work on patches to make it complete and pass __user attribute
> all the way to debug info.

Great! That's what I need. Could you point where (or who) I should check the
implementation?
I guess it will add DW_AT_segment to variable instance, if so it is easy
to support it in perf probe.

> 
> If somebody can work with gcc folks to do the same that would be awesome.
> 

Thank you,

-- 
Masami Hiramatsu <mhiramat@xxxxxxxxxx>