diff mbox series

[v6,bpf-next,2/4] bpf: allow bpf_d_path in sleepable bpf_iter program

Message ID 20210212014232.414643-3-songliubraving@fb.com (mailing list archive)
State Superseded
Delegated to: BPF
Headers show
Series introduce bpf_iter for task_vma | expand

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netdev/tree_selection success Clearly marked for bpf-next
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netdev/cc_maintainers warning 6 maintainers not CCed: mingo@redhat.com kafai@fb.com rostedt@goodmis.org kpsingh@kernel.org john.fastabend@gmail.com andrii@kernel.org
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netdev/module_param success Was 0 now: 0
netdev/build_32bit success Errors and warnings before: 33 this patch: 33
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netdev/checkpatch success total: 0 errors, 0 warnings, 0 checks, 11 lines checked
netdev/build_allmodconfig_warn success Errors and warnings before: 33 this patch: 33
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netdev/stable success Stable not CCed

Commit Message

Song Liu Feb. 12, 2021, 1:42 a.m. UTC 
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 <yhs@fb.com>
Signed-off-by: Song Liu <songliubraving@fb.com>
---
 kernel/trace/bpf_trace.c | 5 +++++
 1 file changed, 5 insertions(+)
diff mbox series

Patch

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);