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.
