On Thu, Jun 18, 2020 at 09:35:10PM -0700, Andrii Nakryiko wrote:
> On Tue, Jun 16, 2020 at 3:07 AM Jiri Olsa <jolsa@xxxxxxxxxx> wrote:
> >
> > Adding d_path helper function that returns full path
> > for give 'struct path' object, which needs to be the
> > kernel BTF 'path' object.
> >
> > The helper calls directly d_path function.
> >
> > Updating also bpf.h tools uapi header and adding
> > 'path' to bpf_helpers_doc.py script.
> >
> > Signed-off-by: Jiri Olsa <jolsa@xxxxxxxxxx>
> > ---
> > include/linux/bpf.h | 4 ++++
> > include/uapi/linux/bpf.h | 14 ++++++++++++-
> > kernel/bpf/btf_ids.c | 11 ++++++++++
> > kernel/trace/bpf_trace.c | 38 ++++++++++++++++++++++++++++++++++
> > scripts/bpf_helpers_doc.py | 2 ++
> > tools/include/uapi/linux/bpf.h | 14 ++++++++++++-
> > 6 files changed, 81 insertions(+), 2 deletions(-)
> >
> > diff --git a/include/linux/bpf.h b/include/linux/bpf.h
> > index a94e85c2ec50..d35265b6c574 100644
> > --- a/include/linux/bpf.h
> > +++ b/include/linux/bpf.h
> > @@ -1752,5 +1752,9 @@ extern int bpf_skb_output_btf_ids[];
> > extern int bpf_seq_printf_btf_ids[];
> > extern int bpf_seq_write_btf_ids[];
> > extern int bpf_xdp_output_btf_ids[];
> > +extern int bpf_d_path_btf_ids[];
> > +
> > +extern int btf_whitelist_d_path[];
> > +extern int btf_whitelist_d_path_cnt;
>
> So with suggestion from previous patch, this would be declared as:
>
> extern const struct btf_id_set btf_whitelist_d_path;
yes
SNIP
> > /* integer value in 'imm' field of BPF_CALL instruction selects which helper
> > * function eBPF program intends to call
> > diff --git a/kernel/bpf/btf_ids.c b/kernel/bpf/btf_ids.c
> > index d8d0df162f04..853c8fd59b06 100644
> > --- a/kernel/bpf/btf_ids.c
> > +++ b/kernel/bpf/btf_ids.c
> > @@ -13,3 +13,14 @@ BTF_ID(struct, seq_file)
> >
> > BTF_ID_LIST(bpf_xdp_output_btf_ids)
> > BTF_ID(struct, xdp_buff)
> > +
> > +BTF_ID_LIST(bpf_d_path_btf_ids)
> > +BTF_ID(struct, path)
> > +
> > +BTF_WHITELIST_ENTRY(btf_whitelist_d_path)
> > +BTF_ID(func, vfs_truncate)
> > +BTF_ID(func, vfs_fallocate)
> > +BTF_ID(func, dentry_open)
> > +BTF_ID(func, vfs_getattr)
> > +BTF_ID(func, filp_close)
> > +BTF_WHITELIST_END(btf_whitelist_d_path)
>
> Oh, so that's why you added btf_ids.c. Do you think centralizing all
> those BTF ID lists in one file is going to be more convenient? I lean
> towards keeping them closer to where they are used, as it was with all
> those helper BTF IDS. But I wonder what others think...
either way works for me, but then BTF_ID_* macros needs to go
to include/linux/btf_ids.h header right?
jirka
>
> > diff --git a/kernel/trace/bpf_trace.c b/kernel/trace/bpf_trace.c
> > index c1866d76041f..0ff5d8434d40 100644
> > --- a/kernel/trace/bpf_trace.c
> > +++ b/kernel/trace/bpf_trace.c
> > @@ -1016,6 +1016,42 @@ static const struct bpf_func_proto bpf_send_signal_thread_proto = {
> > .arg1_type = ARG_ANYTHING,
> > };
> >
>
> [...]
>
