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=-11.4 required=3.0 tests=DKIMWL_WL_MED,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI, SPF_HELO_NONE,SPF_PASS,USER_AGENT_GIT,USER_IN_DEF_DKIM_WL 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 8AECFC432C2 for ; Wed, 25 Sep 2019 23:43:28 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 5C5FF21D7B for ; Wed, 25 Sep 2019 23:43:28 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b="gmrYnfSy" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1733017AbfIYXnY (ORCPT ); Wed, 25 Sep 2019 19:43:24 -0400 Received: from mail-pf1-f202.google.com ([209.85.210.202]:56606 "EHLO mail-pf1-f202.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1732977AbfIYXnV (ORCPT ); Wed, 25 Sep 2019 19:43:21 -0400 Received: by mail-pf1-f202.google.com with SMTP id m25so353582pfa.23 for ; Wed, 25 Sep 2019 16:43:19 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20161025; h=date:message-id:mime-version:subject:from:to:cc; bh=letqQmLXhJ26rePJwfyNH6mOlQABi2YzpNRsxYXK53E=; b=gmrYnfSyTw1f26hABnX/14Tb9gHphBFSw9ysWsgslFndsIS/thnap2A+ID8uNwvGyr F7l1E+w5g3Hr1Imb/26usjnR+JYI70d9JOEXVJz4ZMI/wCTVSWWtM7AXAD0TpMP+Z6XM ASQTuWmoxQxoN/2VnRYGrfqpewkdqCwkbBsmhFCWZnCbYu4jWNlMSCV+iLV8uW0Q0Lif Ik3IeqlI2VjdwTtVN60S+lOApHVsy6ljioP7tLO7E+d94Pe8dMcMQ7iCbSfTOXez8EYh ugWmWP4uscscHN/HxOLgxnwxQQKqIVsRMCdzmFiETn6bUHWpv3JptiifMAgF+TJqPenD tb4A== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:date:message-id:mime-version:subject:from:to:cc; bh=letqQmLXhJ26rePJwfyNH6mOlQABi2YzpNRsxYXK53E=; b=kwf/cHyZ9uC3+iiEcFtwqcdW4OYQe+H9Bt5lo7jPwJuZerkzDr9wjSPRFxnKEAfNsD sdDUqyq1T1XHxqgFt9kDrQ7t/1gsBnt3ezI1U/YEQsW2ExlmTslYEH7aZJYncveir5c8 PqEe/abv4QerCYDtwJHRMgWRMbmDFxukyFlwTDlsxzzYHAUGbwV2gBDQieYHLZy2iK58 TvMfO1W3iTQsOILeQ5R3YNbn2Cm+/4OJR2lLF0OYPgHRbF16YdkAEGycvi9jA18fOReD 94o4kRoQABdl9hPc2slKJqrkogAfx7szOXNBQM8/gbDRNDMpm26OdwIilMJvdzJieqML VC6g== X-Gm-Message-State: APjAAAVegs2tEcIVOUMZ8qH+5L0XYPQbOuWaABq5sONKqQhk/TvFiyb4 lh9efTWc0IQQi97WVB4i1rE5GLaCKhY51BIC X-Google-Smtp-Source: APXvYqxQVs372ouu+aLaaayQVqtcE03MHqaadSJn7DSgd+z9iXf12wBvc9lGG+0dcKkpCNi+16J0Keb/KJRGd+Aa X-Received: by 2002:a63:2104:: with SMTP id h4mr428099pgh.295.1569454998771; Wed, 25 Sep 2019 16:43:18 -0700 (PDT) Date: Wed, 25 Sep 2019 16:43:11 -0700 Message-Id: <20190925234312.94063-1-allanzhang@google.com> Mime-Version: 1.0 X-Mailer: git-send-email 2.23.0.351.gc4317032e6-goog Subject: [PATCH 0/1] bpf: Fix bpf_event_output re-entry issue From: Allan Zhang To: daniel@iogearbox.net, songliubraving@fb.com, netdev@vger.kernel.org, bpf@vger.kernel.org Cc: linux-kernel@vger.kernel.org, Allan Zhang Content-Type: text/plain; charset="UTF-8" Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org BPF_PROG_TYPE_SOCK_OPS program can reenter bpf_event_output because it can be called from atomic and non-atomic contexts since we don't have bpf_prog_active to prevent it happen. This patch enables 3 level of nesting to support normal, irq and nmi context. We can easily reproduce the issue by running neper crr mode with 100 flows and 10 threads from neper client side. Allan Zhang (1): bpf: Fix bpf_event_output re-entry issue kernel/trace/bpf_trace.c | 26 +++++++++++++++++++++----- 1 file changed, 21 insertions(+), 5 deletions(-) -- 2.23.0.351.gc4317032e6-goog