On Sat, Aug 01, 2020 at 08:13:42PM -0700, Alexei Starovoitov wrote:
> On Sat, Aug 01, 2020 at 07:03:18PM +0200, Jiri Olsa wrote:
> > Adding d_path helper function that returns full path for
> > given 'struct path' object, which needs to be the kernel
> > BTF 'path' object. The path is returned in buffer provided
> > 'buf' of size 'sz' and is zero terminated.
> >
> > bpf_d_path(&file->f_path, buf, size);
> >
> > The helper calls directly d_path function, so there's only
> > limited set of function it can be called from. Adding just
> > very modest set for the start.
> >
> > Updating also bpf.h tools uapi header and adding 'path' to
> > bpf_helpers_doc.py script.
> >
> > Signed-off-by: Jiri Olsa <jolsa@xxxxxxxxxx>
> > ---
> > include/uapi/linux/bpf.h | 13 +++++++++
> > kernel/trace/bpf_trace.c | 48 ++++++++++++++++++++++++++++++++++
> > scripts/bpf_helpers_doc.py | 2 ++
> > tools/include/uapi/linux/bpf.h | 13 +++++++++
> > 4 files changed, 76 insertions(+)
> >
> > diff --git a/include/uapi/linux/bpf.h b/include/uapi/linux/bpf.h
> > index eb5e0c38eb2c..a356ea1357bf 100644
> > --- a/include/uapi/linux/bpf.h
> > +++ b/include/uapi/linux/bpf.h
> > @@ -3389,6 +3389,18 @@ union bpf_attr {
> > * A non-negative value equal to or less than *size* on success,
> > * or a negative error in case of failure.
> > *
> > + * int bpf_d_path(struct path *path, char *buf, u32 sz)
>
> Please make it return 'long'. As you well ware the generated code will be better.
>
will do, thanks
jirka
