Re: [RFC bpf-next 07/12] bpf: Add support to create tracing multi link

On Wed, Feb 04, 2026 at 11:05:09AM -0800, Andrii Nakryiko wrote:

On Tue, Feb 3, 2026 at 1:39 AM Jiri Olsa [off-list ref] wrote:

quoted

Adding new link to allow to attach program to multiple function
BTF IDs. The link is represented by struct bpf_tracing_multi_link.

To configure the link, new fields are added to bpf_attr::link_create
to pass array of BTF IDs;

  struct {
      __aligned_u64   btf_ids;        /* addresses to attach */
      __u32           btf_ids_cnt;    /* addresses count */

cookies suspiciously missing?

right, need to be added, no mystery there ;-)

we will just assign it to the bpf_tramp_node object for each trampoline/id

thanks,
jirka

quoted

  } tracing_multi;

Each BTF ID represents function (BTF_KIND_FUNC) that the link will
attach bpf program to.

We use previously added bpf_trampoline_multi_attach/detach functions
to attach/detach the link.

Signed-off-by: Jiri Olsa <jolsa@kernel.org>
---
 include/linux/trace_events.h   |   6 ++
 include/uapi/linux/bpf.h       |   5 ++
 kernel/bpf/syscall.c           |   2 +
 kernel/trace/bpf_trace.c       | 105 +++++++++++++++++++++++++++++++++
 tools/include/uapi/linux/bpf.h |   5 ++
 5 files changed, 123 insertions(+)

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