* [PATCH bpf-next] bpf: Allow bpf_current_task_under_cgroup in interrupt
@ 2018-04-28 7:32 Teng Qin
2018-04-28 15:03 ` Alexei Starovoitov
2018-04-29 6:39 ` [PATCH bpf-next v2] " Teng Qin
0 siblings, 2 replies; 4+ messages in thread
From: Teng Qin @ 2018-04-28 7:32 UTC (permalink / raw)
To: netdev; +Cc: ast, daniel, yhs, kernel-team, Teng Qin
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.
---
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
^ permalink raw reply related [flat|nested] 4+ messages in thread
* Re: [PATCH bpf-next] bpf: Allow bpf_current_task_under_cgroup in interrupt
2018-04-28 7:32 [PATCH bpf-next] bpf: Allow bpf_current_task_under_cgroup in interrupt Teng Qin
@ 2018-04-28 15:03 ` Alexei Starovoitov
2018-04-29 6:39 ` [PATCH bpf-next v2] " Teng Qin
1 sibling, 0 replies; 4+ messages in thread
From: Alexei Starovoitov @ 2018-04-28 15:03 UTC (permalink / raw)
To: Teng Qin, netdev; +Cc: ast, daniel, yhs, kernel-team
On 4/28/18 12:32 AM, Teng Qin wrote:
> 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.
> ---
> 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;
>
looks good, but SOB is missing. Please respin.
^ permalink raw reply [flat|nested] 4+ messages in thread
* [PATCH bpf-next v2] bpf: Allow bpf_current_task_under_cgroup in interrupt
2018-04-28 7:32 [PATCH bpf-next] bpf: Allow bpf_current_task_under_cgroup in interrupt Teng Qin
2018-04-28 15:03 ` Alexei Starovoitov
@ 2018-04-29 6:39 ` Teng Qin
2018-04-29 16:20 ` Alexei Starovoitov
1 sibling, 1 reply; 4+ messages in thread
From: Teng Qin @ 2018-04-29 6:39 UTC (permalink / raw)
To: netdev; +Cc: ast, daniel, yhs, kernel-team, Teng Qin
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 <qinteng@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
^ permalink raw reply related [flat|nested] 4+ messages in thread
* Re: [PATCH bpf-next v2] bpf: Allow bpf_current_task_under_cgroup in interrupt
2018-04-29 6:39 ` [PATCH bpf-next v2] " Teng Qin
@ 2018-04-29 16:20 ` Alexei Starovoitov
0 siblings, 0 replies; 4+ messages in thread
From: Alexei Starovoitov @ 2018-04-29 16:20 UTC (permalink / raw)
To: Teng Qin; +Cc: netdev, ast, daniel, yhs, kernel-team
On Sat, Apr 28, 2018 at 11:39:29PM -0700, Teng Qin wrote:
> 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 <qinteng@fb.com>
Applied, Thanks Teng.
^ permalink raw reply [flat|nested] 4+ messages in thread
end of thread, other threads:[~2018-04-29 16:21 UTC | newest]
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2018-04-28 7:32 [PATCH bpf-next] bpf: Allow bpf_current_task_under_cgroup in interrupt Teng Qin
2018-04-28 15:03 ` Alexei Starovoitov
2018-04-29 6:39 ` [PATCH bpf-next v2] " Teng Qin
2018-04-29 16:20 ` Alexei Starovoitov
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