On Sun, Sep 29, 2024 at 1:58 PM Jiri Olsa <jolsa@xxxxxxxxxx> wrote:
>
> Adding support to attach program in uprobe session mode
> with bpf_program__attach_uprobe_multi function.
>
> Adding session bool to bpf_uprobe_multi_opts struct that allows
> to load and attach the bpf program via uprobe session.
> the attachment to create uprobe multi session.
>
> Also adding new program loader section that allows:
> SEC("uprobe.session/bpf_fentry_test*")
>
> and loads/attaches uprobe program as uprobe session.
>
> Adding sleepable hook (uprobe.session.s) as well.
>
> Signed-off-by: Jiri Olsa <jolsa@xxxxxxxxxx>
> ---
> tools/lib/bpf/bpf.c | 1 +
> tools/lib/bpf/libbpf.c | 21 ++++++++++++++++++---
> tools/lib/bpf/libbpf.h | 4 +++-
> 3 files changed, 22 insertions(+), 4 deletions(-)
>
LGTM, though see the nit below
Acked-by: Andrii Nakryiko <andrii@xxxxxxxxxx>
> diff --git a/tools/lib/bpf/bpf.c b/tools/lib/bpf/bpf.c
> index 2a4c71501a17..becdfa701c75 100644
> --- a/tools/lib/bpf/bpf.c
> +++ b/tools/lib/bpf/bpf.c
> @@ -776,6 +776,7 @@ int bpf_link_create(int prog_fd, int target_fd,
> return libbpf_err(-EINVAL);
> break;
> case BPF_TRACE_UPROBE_MULTI:
> + case BPF_TRACE_UPROBE_SESSION:
> attr.link_create.uprobe_multi.flags = OPTS_GET(opts, uprobe_multi.flags, 0);
> attr.link_create.uprobe_multi.cnt = OPTS_GET(opts, uprobe_multi.cnt, 0);
> attr.link_create.uprobe_multi.path = ptr_to_u64(OPTS_GET(opts, uprobe_multi.path, 0));
> diff --git a/tools/lib/bpf/libbpf.c b/tools/lib/bpf/libbpf.c
> index 3587ed7ec359..563ff5e64269 100644
> --- a/tools/lib/bpf/libbpf.c
> +++ b/tools/lib/bpf/libbpf.c
> @@ -9410,8 +9410,10 @@ static const struct bpf_sec_def section_defs[] = {
> SEC_DEF("kprobe.session+", KPROBE, BPF_TRACE_KPROBE_SESSION, SEC_NONE, attach_kprobe_session),
> SEC_DEF("uprobe.multi+", KPROBE, BPF_TRACE_UPROBE_MULTI, SEC_NONE, attach_uprobe_multi),
> SEC_DEF("uretprobe.multi+", KPROBE, BPF_TRACE_UPROBE_MULTI, SEC_NONE, attach_uprobe_multi),
> + SEC_DEF("uprobe.session+", KPROBE, BPF_TRACE_UPROBE_SESSION, SEC_NONE, attach_uprobe_multi),
> SEC_DEF("uprobe.multi.s+", KPROBE, BPF_TRACE_UPROBE_MULTI, SEC_SLEEPABLE, attach_uprobe_multi),
> SEC_DEF("uretprobe.multi.s+", KPROBE, BPF_TRACE_UPROBE_MULTI, SEC_SLEEPABLE, attach_uprobe_multi),
> + SEC_DEF("uprobe.session.s+", KPROBE, BPF_TRACE_UPROBE_SESSION, SEC_SLEEPABLE, attach_uprobe_multi),
> SEC_DEF("ksyscall+", KPROBE, 0, SEC_NONE, attach_ksyscall),
> SEC_DEF("kretsyscall+", KPROBE, 0, SEC_NONE, attach_ksyscall),
> SEC_DEF("usdt+", KPROBE, 0, SEC_USDT, attach_usdt),
> @@ -11733,7 +11735,10 @@ static int attach_uprobe_multi(const struct bpf_program *prog, long cookie, stru
> ret = 0;
> break;
> case 3:
> - opts.retprobe = str_has_pfx(probe_type, "uretprobe.multi");
> + if (str_has_pfx(probe_type, "uprobe.session"))
> + opts.session = true;
> + else
> + opts.retprobe = str_has_pfx(probe_type, "uretprobe.multi");
nit: this is very non-uniform, can you please just do:
opts.session = str_has_pfx(probe_type, "uprobe.session");
opts.retprobe = str_has_pfx(probe_type, "uretprobe.multi");
There is no need to micro-optimize str_has_pfx() calls, IMO.
> *link = bpf_program__attach_uprobe_multi(prog, -1, binary_path, func_name, &opts);
> ret = libbpf_get_error(*link);
> break;
[...]
