mbox series

[bpf-next,v2,0/2] bpftool/libbpf: Add probe for large INSN limit

Message ID 20200107130308.20242-1-mrostecki@opensuse.org
Headers show
Series bpftool/libbpf: Add probe for large INSN limit | expand

Message

Michal Rostecki Jan. 7, 2020, 1:03 p.m. UTC 
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 the current 1M limit from probe's description.

Michal Rostecki (2):
  libbpf: Add probe for large INSN limit
  bpftool: Add misc secion 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(+)