Re: [PATCHv5 bpf-next 06/13] libbpf: Add support for uprobe multi session attach
From: Andrii Nakryiko <hidden>
Date: 2024-09-30 21:36:48
Also in:
bpf, lkml
On Sun, Sep 29, 2024 at 1:58 PM Jiri Olsa [off-list ref] 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@kernel.org>
---
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@kernel.org>
quoted hunk ↗ jump to hunk
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;[...]