[PATCH bpf-next v3 0/2] bpftool/libbpf: Add probe for large INSN limit

From: Michal Rostecki
Date: Wed Jan 08 2020 - 11:24:44 EST


This series implements a new BPF feature probe which checks for the
commit c04c0d2b968a ("bpf: increase complexity limit and maximum program
size"), which increases the maximum program size to 1M. It's based on
the similar check in Cilium, although Cilium is already aiming to use
bpftool checks and eventually drop all its custom checks.

Examples of outputs:

# bpftool feature probe
[...]
Scanning miscellaneous eBPF features...
Large complexity limit and maximum program size (1M) is available

# bpftool feature probe macros
[...]
/*** eBPF misc features ***/
#define HAVE_HAVE_LARGE_INSN_LIMIT

# bpftool feature probe -j | jq '.["misc"]'
{
"have_large_insn_limit": true
}

v1 -> v2:
- Test for 'BPF_MAXINSNS + 1' number of total insns.
- Remove info about current 1M limit from probe's description.

v2 -> v3:
- Remove the "complexity" word from probe's description.

Michal Rostecki (2):
libbpf: Add probe for large INSN limit
bpftool: Add misc section and probe for large INSN limit

tools/bpf/bpftool/feature.c | 18 ++++++++++++++++++
tools/lib/bpf/libbpf.h | 1 +
tools/lib/bpf/libbpf.map | 1 +
tools/lib/bpf/libbpf_probes.c | 21 +++++++++++++++++++++
4 files changed, 41 insertions(+)

--
2.16.4