Re: [PATCH bpf-next v4 09/27] bpf: Add support to load multi func tracing program

On Thu, Aug 26, 2021 at 12:40 PM Jiri Olsa [off-list ref] wrote:

Adding support to load tracing program with new BPF_F_MULTI_FUNC flag,
that allows the program to be loaded without specific function to be
attached to.

Are there any benefits to using a new load flag vs having separate
expected attach types like FENTRY_MULTI/FEXIT_MULTI? I find load flags
a bigger pain to work with compared to expected attach type (and
expected attach type should be more apparent in BPF link info, bpftool
output, etc).

Such program will be allowed to be attached to multiple functions
in following patches.

Signed-off-by: Jiri Olsa <jolsa@kernel.org>
---
 include/linux/bpf.h            |  1 +
 include/uapi/linux/bpf.h       |  7 +++++++
 kernel/bpf/syscall.c           | 35 +++++++++++++++++++++++++++++-----
 kernel/bpf/verifier.c          |  3 ++-
 tools/include/uapi/linux/bpf.h |  7 +++++++
 5 files changed, 47 insertions(+), 6 deletions(-)

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