From: Teng Qin Date: Sun, 29 Apr 2018 06:39:29 +0000 (-0700) Subject: bpf: Allow bpf_current_task_under_cgroup in interrupt X-Git-Url: http://git.cdn.openwrt.org/?a=commitdiff_plain;h=7ef3771205302a71a8bb4a2286ef98e5cade5d1a;p=openwrt%2Fstaging%2Fblogic.git bpf: Allow bpf_current_task_under_cgroup in interrupt 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 Signed-off-by: Alexei Starovoitov --- diff --git a/kernel/trace/bpf_trace.c b/kernel/trace/bpf_trace.c index 46d866e9937c..ce2cbbff27e4 100644 --- a/kernel/trace/bpf_trace.c +++ b/kernel/trace/bpf_trace.c @@ -475,8 +475,6 @@ 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;