From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-3.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS autolearn=no autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 6B31CC2BA83 for ; Fri, 14 Feb 2020 16:45:48 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 44E682187F for ; Fri, 14 Feb 2020 16:45:48 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2406127AbgBNQpr (ORCPT ); Fri, 14 Feb 2020 11:45:47 -0500 Received: from Galois.linutronix.de ([193.142.43.55]:55559 "EHLO Galois.linutronix.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2392978AbgBNQVc (ORCPT ); Fri, 14 Feb 2020 11:21:32 -0500 Received: from [5.158.153.52] (helo=nanos.tec.linutronix.de) by Galois.linutronix.de with esmtpsa (TLS1.2:DHE_RSA_AES_256_CBC_SHA256:256) (Exim 4.80) (envelope-from ) id 1j2diI-0003IK-IW; Fri, 14 Feb 2020 17:21:10 +0100 Received: from nanos.tec.linutronix.de (localhost [IPv6:::1]) by nanos.tec.linutronix.de (Postfix) with ESMTP id 4A130101DF6; Fri, 14 Feb 2020 17:21:05 +0100 (CET) Message-Id: <20200214161503.702891999@linutronix.de> User-Agent: quilt/0.65 Date: Fri, 14 Feb 2020 14:39:25 +0100 From: Thomas Gleixner To: LKML Cc: David Miller , bpf@vger.kernel.org, netdev@vger.kernel.org, Alexei Starovoitov , Daniel Borkmann , Sebastian Sewior , Peter Zijlstra , Clark Williams , Steven Rostedt , Juri Lelli , Ingo Molnar Subject: [RFC patch 08/19] bpf: Replace cant_sleep() with cant_migrate() References: <20200214133917.304937432@linutronix.de> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Sender: bpf-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: bpf@vger.kernel.org As already discussed in the previous change which introduced BPF_RUN_PROG_PIN_ON_CPU() BPF only requires to disable migration to guarantee per CPUness. If RT substitutes the preempt disable based migration protection then the cant_sleep() check will obviously trigger as preemption is not disabled. Replace it by cant_migrate() which maps to cant_sleep() on a non RT kernel and will verify that migration is disabled on a full RT kernel. Signed-off-by: Thomas Gleixner --- include/linux/filter.h | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) --- a/include/linux/filter.h +++ b/include/linux/filter.h @@ -561,7 +561,7 @@ DECLARE_STATIC_KEY_FALSE(bpf_stats_enabl #define __BPF_PROG_RUN(prog, ctx, dfunc) ({ \ u32 ret; \ - cant_sleep(); \ + cant_migrate(); \ if (static_branch_unlikely(&bpf_stats_enabled_key)) { \ struct bpf_prog_stats *stats; \ u64 start = sched_clock(); \