diff options
| author |   Song Liu <songliubraving@fb.com> | 2020-07-23 11:06:45 -0700 |
|---|---|---|
| committer |   Alexei Starovoitov <ast@kernel.org> | 2020-07-25 20:16:34 -0700 |
| commit | 5d99cb2c86775b4780c02a339a9578bf9471ead9 (patch) | |
| tree | 25c9829e8b83c8066b286c414821fac40a4e3c04 /kernel/bpf | |
| parent | bpf: Separate bpf_get_[stack|stackid] for perf events BPF (diff) | |
| download | wireguard-linux-5d99cb2c86775b4780c02a339a9578bf9471ead9.tar.xz wireguard-linux-5d99cb2c86775b4780c02a339a9578bf9471ead9.zip | |
bpf: Fail PERF_EVENT_IOC_SET_BPF when bpf_get_[stack|stackid] cannot work
bpf_get_[stack|stackid] on perf_events with precise_ip uses callchain
attached to perf_sample_data. If this callchain is not presented, do not
allow attaching BPF program that calls bpf_get_[stack|stackid] to this
event.
In the error case, -EPROTO is returned so that libbpf can identify this
error and print proper hint message.
Signed-off-by: Song Liu <songliubraving@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20200723180648.1429892-3-songliubraving@fb.com
Diffstat (limited to 'kernel/bpf')
| -rw-r--r-- | kernel/bpf/verifier.c | 3 |
1 files changed, 3 insertions, 0 deletions
diff --git a/kernel/bpf/verifier.c b/kernel/bpf/verifier.c index 8d6979db48d8..cd14e70f2d07 100644 --- a/kernel/bpf/verifier.c +++ b/kernel/bpf/verifier.c @@ -4962,6 +4962,9 @@ static int check_helper_call(struct bpf_verifier_env *env, int func_id, int insn env->prog->has_callchain_buf = true; } + if (func_id == BPF_FUNC_get_stackid || func_id == BPF_FUNC_get_stack) + env->prog->call_get_stack = true; + if (changes_data) clear_all_pkt_pointers(env); return 0; |