Re: [PATCHv4 bpf-next 6/8] libbpf: Add bpf_program__attach_kprobe_opts function

On Fri, Jul 16, 2021 at 06:41:59PM -0700, Andrii Nakryiko wrote:

On Wed, Jul 14, 2021 at 2:45 AM Jiri Olsa [off-list ref] wrote:

quoted

Adding bpf_program__attach_kprobe_opts that does the same
as bpf_program__attach_kprobe, but takes opts argument.

Currently opts struct holds just retprobe bool, but we will
add new field in following patch.

The function is not exported, so there's no need to add
size to the struct bpf_program_attach_kprobe_opts for now.

Why not exported? Please use a proper _opts struct just like others
(e.g., bpf_object_open_opts) and add is as a public API, it's a useful
addition. We are going to have a similar structure for attach_uprobe,
btw. Please send a follow up patch.

there's no outside user.. ok

quoted

Signed-off-by: Jiri Olsa <jolsa@kernel.org>
---
 tools/lib/bpf/libbpf.c | 34 +++++++++++++++++++++++++---------
 1 file changed, 25 insertions(+), 9 deletions(-)

diff --git a/tools/lib/bpf/libbpf.c b/tools/lib/bpf/libbpf.c
index 88b99401040c..d93a6f9408d1 100644
--- a/tools/lib/bpf/libbpf.c
+++ b/tools/lib/bpf/libbpf.c

@@ -10346,19 +10346,24 @@ static int perf_event_open_probe(bool uprobe, bool retprobe, const char *name,
        return pfd;
 }

-struct bpf_link *bpf_program__attach_kprobe(struct bpf_program *prog,
-                                           bool retprobe,
-                                           const char *func_name)
+struct bpf_program_attach_kprobe_opts {

when you make it part of libbpf API, let's call it something shorter,
like bpf_kprobe_opts, maybe? And later we'll have bpf_uprobe_opts for
uprobes. Short and unambiguous.

ok

jirka

quoted

+       bool retprobe;
+};
+
+static struct bpf_link*
+bpf_program__attach_kprobe_opts(struct bpf_program *prog,
+                               const char *func_name,
+                               struct bpf_program_attach_kprobe_opts *opts)
 {
        char errmsg[STRERR_BUFSIZE];
        struct bpf_link *link;
        int pfd, err;

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