Currently, the bpf_current_task_under_cgroup helper has a check where if
the BPF program is running in_interrupt(), it will return -EINVAL. This
prevents the helper to be used in many useful scenarios, particularly
BPF programs attached to Perf Events.
This commit removes the check. Tested a few NMI (Perf Event) and some
softirq context, the helper returns the correct result.
Signed-off-by: Teng Qin <qint...@fb.com>
---
kernel/trace/bpf_trace.c | 2 --
1 file changed, 2 deletions(-)
diff --git a/kernel/trace/bpf_trace.c b/kernel/trace/bpf_trace.c
index 56ba0f2..f94890c 100644
--- a/kernel/trace/bpf_trace.c
+++ b/kernel/trace/bpf_trace.c
@@ -474,8 +474,6 @@ BPF_CALL_2(bpf_current_task_under_cgroup, struct bpf_map *,
map, u32, idx)
struct bpf_array *array = container_of(map, struct bpf_array, map);
struct cgroup *cgrp;
- if (unlikely(in_interrupt()))
- return -EINVAL;
if (unlikely(idx >= array->map.max_entries))
return -E2BIG;
--
2.9.5
