[PATCH v5 bpf-next 2/4] bpf: allow bpf_d_path in sleepable bpf_iter program
From: Song Liu <hidden>
Date: 2021-02-08 22:53:11
Also in:
linux-mm, netdev
Subsystem:
bpf [general] (safe dynamic programs and tools), bpf [security & lsm] (security audit and enforcement using bpf), bpf [tracing], the rest, tracing · Maintainers:
Alexei Starovoitov, Daniel Borkmann, Andrii Nakryiko, Eduard Zingerman, Kumar Kartikeya Dwivedi, KP Singh, Matt Bobrowski, Song Liu, Linus Torvalds, Steven Rostedt, Masami Hiramatsu
task_file and task_vma iter programs have access to file->f_path. Enable bpf_d_path to print paths of these file. bpf_iter programs are generally called in sleepable context. However, it is still necessary to diffientiate sleepable and non-sleepable bpf_iter programs: sleepable programs have access to bpf_d_path; non-sleepable programs have access to bpf_spin_lock. Acked-by: Yonghong Song <redacted> Signed-off-by: Song Liu <redacted> --- kernel/trace/bpf_trace.c | 5 +++++ 1 file changed, 5 insertions(+)
diff --git a/kernel/trace/bpf_trace.c b/kernel/trace/bpf_trace.c
index 6c0018abe68a0..1f3becd4435ae 100644
--- a/kernel/trace/bpf_trace.c
+++ b/kernel/trace/bpf_trace.c@@ -1191,6 +1191,11 @@ BTF_SET_END(btf_allowlist_d_path) static bool bpf_d_path_allowed(const struct bpf_prog *prog) { + if (prog->type == BPF_PROG_TYPE_TRACING && + prog->expected_attach_type == BPF_TRACE_ITER && + prog->aux->sleepable) + return true; + if (prog->type == BPF_PROG_TYPE_LSM) return bpf_lsm_is_sleepable_hook(prog->aux->attach_btf_id);
--
2.24.1