diff options
| author | Michal Rostecki <mrostecki@opensuse.org> | 2020-01-08 19:23:52 +0300 |
|---|---|---|
| committer | Daniel Borkmann <daniel@iogearbox.net> | 2020-01-08 21:31:35 +0300 |
| commit | 5ff051200308ab6f4c64c0fe52187bf4a1234dac (patch) | |
| tree | 16c2c9c645d2acc8f0a4d52c6e54619db7a799d7 | |
| parent | 1ece2fbe9b427d379455f18a874bcd3ab86a2419 (diff) | |
| download | linux-5ff051200308ab6f4c64c0fe52187bf4a1234dac.tar.xz | |
libbpf: Add probe for large INSN limit
Introduce a new probe which checks whether kernel has large maximum
program size which was increased in the following commit:
c04c0d2b968a ("bpf: increase complexity limit and maximum program size")
Based on the similar check in Cilium[0], authored by Daniel Borkmann.
[0] https://github.com/cilium/cilium/commit/657d0f585afd26232cfa5d4e70b6f64d2ea91596
Co-authored-by: Daniel Borkmann <daniel@iogearbox.net>
Signed-off-by: Michal Rostecki <mrostecki@opensuse.org>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Reviewed-by: Quentin Monnet <quentin.monnet@netronome.com>
Link: https://lore.kernel.org/bpf/20200108162428.25014-2-mrostecki@opensuse.org
| -rw-r--r-- | tools/lib/bpf/libbpf.h | 1 | ||||
| -rw-r--r-- | tools/lib/bpf/libbpf.map | 1 | ||||
| -rw-r--r-- | tools/lib/bpf/libbpf_probes.c | 21 |
3 files changed, 23 insertions, 0 deletions
diff --git a/tools/lib/bpf/libbpf.h b/tools/lib/bpf/libbpf.h index fe592ef48f1b..26bf539f1b3c 100644 --- a/tools/lib/bpf/libbpf.h +++ b/tools/lib/bpf/libbpf.h @@ -521,6 +521,7 @@ LIBBPF_API bool bpf_probe_prog_type(enum bpf_prog_type prog_type, LIBBPF_API bool bpf_probe_map_type(enum bpf_map_type map_type, __u32 ifindex); LIBBPF_API bool bpf_probe_helper(enum bpf_func_id id, enum bpf_prog_type prog_type, __u32 ifindex); +LIBBPF_API bool bpf_probe_large_insn_limit(__u32 ifindex); /* * Get bpf_prog_info in continuous memory diff --git a/tools/lib/bpf/libbpf.map b/tools/lib/bpf/libbpf.map index e9713a574243..b300d74c921a 100644 --- a/tools/lib/bpf/libbpf.map +++ b/tools/lib/bpf/libbpf.map @@ -219,6 +219,7 @@ LIBBPF_0.0.7 { bpf_object__detach_skeleton; bpf_object__load_skeleton; bpf_object__open_skeleton; + bpf_probe_large_insn_limit; bpf_prog_attach_xattr; bpf_program__attach; bpf_program__name; diff --git a/tools/lib/bpf/libbpf_probes.c b/tools/lib/bpf/libbpf_probes.c index a9eb8b322671..221e6ad97012 100644 --- a/tools/lib/bpf/libbpf_probes.c +++ b/tools/lib/bpf/libbpf_probes.c @@ -321,3 +321,24 @@ bool bpf_probe_helper(enum bpf_func_id id, enum bpf_prog_type prog_type, return res; } + +/* + * Probe for availability of kernel commit (5.3): + * + * c04c0d2b968a ("bpf: increase complexity limit and maximum program size") + */ +bool bpf_probe_large_insn_limit(__u32 ifindex) +{ + struct bpf_insn insns[BPF_MAXINSNS + 1]; + int i; + + for (i = 0; i < BPF_MAXINSNS; i++) + insns[i] = BPF_MOV64_IMM(BPF_REG_0, 1); + insns[BPF_MAXINSNS] = BPF_EXIT_INSN(); + + errno = 0; + probe_load(BPF_PROG_TYPE_SCHED_CLS, insns, ARRAY_SIZE(insns), NULL, 0, + ifindex); + + return errno != E2BIG && errno != EINVAL; +} |