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 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id C1C35C4332F for ; Wed, 17 Nov 2021 14:07:22 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id AA5E461B54 for ; Wed, 17 Nov 2021 14:07:22 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S238130AbhKQOKT (ORCPT ); Wed, 17 Nov 2021 09:10:19 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:51820 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S238110AbhKQOKS (ORCPT ); Wed, 17 Nov 2021 09:10:18 -0500 Received: from mail-oi1-x229.google.com (mail-oi1-x229.google.com [IPv6:2607:f8b0:4864:20::229]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 1CE8AC061766 for ; Wed, 17 Nov 2021 06:07:20 -0800 (PST) Received: by mail-oi1-x229.google.com with SMTP id m6so6695532oim.2 for ; Wed, 17 Nov 2021 06:07:20 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20210112; h=mime-version:references:in-reply-to:from:date:message-id:subject:to :cc; bh=ZKI8nFkBZ809K78BP8XN2WIPmfawnsA2haGWJ5EUF2U=; b=CLYTQIRYgo58EhTlJFLjBW7Z3IzIMiGHvbCR8Gte1LGdPz1H3PLYCPLqttw9h3qk1c 1S9DTzqW6Od9d7QaEZ4gB06b2+XJy2qxBHbJOX+bEQHEty6B1X5aO1qBTWCBYft/TPYR Sf0+OGR0vHx2dhZ+Rju75nFNP+47AeZ2o4ihbfDknphUZGupx0/WNPnE1N8/BXG4mjTN 2/WVQZonWySOWI8++joQxKzek4lg7QNDLXaUae6hXhnlk8MmahEHy+pc5Wpzjtd3Uovi VGqyoDVW4kSB3Ycng8hLDgzzaUmM+lNgPGeYfweUdKAiduUz0hlyJFAtoVi614HEPo0C GE2g== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to:cc; bh=ZKI8nFkBZ809K78BP8XN2WIPmfawnsA2haGWJ5EUF2U=; b=nhvXH6TPT1QmD3enZbHiRNVZpOPOE0kGB/y6JmXeySPFKarr3DnzGuhNChdvVkZ/ui nKlHXKECg3hTGlaOpC80JN7CGzElz4NiOoMWF/LqsLE8Hqmi4t2nUpXA4f83Dkb0dL+y x61moBVKw6YRPVp9YBoWQojhL11JteUawylvmFpWCgrtFIDgAab/5ulhZzbapgyTlT1v fxt1r/HNaLGG/yUK6X7CWi4f/GlGBr+EL9QTysF7Tb7DPMTg5X0sJyACYhdlXX+2Qs4P QW/xHRHhmBWfMWGTkmabZmJSoJLNNXh+pnMF10ozBDzK/0VB6cfNk7afkNWH4akYVQJc D/KQ== X-Gm-Message-State: AOAM532DkZcE28fuvVRAbphg4F6dyr82sc2tOvK32Lj0EcBFrFYTzacU Cf6V8u2s/U+3hA07NUSEQ6lTZRg8KbnzrQ8qRbGqAg== X-Google-Smtp-Source: ABdhPJwqDgU6tcT6tOY+iRbQRcl7E1Ru7pv08RkQMd8Cl2YNwWk7WhpZF80SVvicWXV0dOpj4vAMM4C8OjioJqkmY2M= X-Received: by 2002:a05:6808:118c:: with SMTP id j12mr14255739oil.65.1637158039276; Wed, 17 Nov 2021 06:07:19 -0800 (PST) MIME-Version: 1.0 References: <00000000000053692705d05a17c1@google.com> In-Reply-To: From: Marco Elver Date: Wed, 17 Nov 2021 15:07:07 +0100 Message-ID: Subject: Re: [PATCH] perf: Ignore sigtrap for tracepoints destined for other tasks To: peterz@infradead.org, mingo@redhat.com, mark.rutland@arm.com, namhyung@kernel.org, acme@kernel.org, alexander.shishkin@linux.intel.com, jolsa@redhat.com Cc: syzbot , andrii@kernel.org, ast@kernel.org, bpf@vger.kernel.org, daniel@iogearbox.net, john.fastabend@gmail.com, kafai@fb.com, kpsingh@kernel.org, linux-kernel@vger.kernel.org, linux-perf-users@vger.kernel.org, netdev@vger.kernel.org, songliubraving@fb.com, syzkaller-bugs@googlegroups.com, yhs@fb.com Content-Type: text/plain; charset="UTF-8" Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, 9 Nov 2021 at 13:22, Marco Elver wrote: > syzbot reported that the warning in perf_sigtrap() fires, saying that > the event's task does not match current: > > | WARNING: CPU: 0 PID: 9090 at kernel/events/core.c:6446 perf_pending_event+0x40d/0x4b0 kernel/events/core.c:6513 [...] > This happened because the 'sched_wakeup' tracepoint also takes a task > argument passed on to perf_tp_event(), which is used to deliver the > event to that other task. > > Since we cannot deliver synchronous signals to other tasks, skip an event if > perf_tp_event() is targeted at another task and perf_event_attr::sigtrap is > set, which will avoid ever entering perf_sigtrap() for such events. [...] Hmm, I made the mistake of sending this in the merge-window. Any comments? Thanks, -- Marco