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=-16.6 required=3.0 tests=DKIMWL_WL_MED,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH, MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED, USER_AGENT_GIT,USER_IN_DEF_DKIM_WL autolearn=ham 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 36118C282CE for ; Wed, 22 May 2019 20:54:05 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id CC35721019 for ; Wed, 22 May 2019 20:54:04 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b="AVOGP9LV" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1730421AbfEVUyE (ORCPT ); Wed, 22 May 2019 16:54:04 -0400 Received: from mail-yb1-f202.google.com ([209.85.219.202]:45727 "EHLO mail-yb1-f202.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1730412AbfEVUyE (ORCPT ); Wed, 22 May 2019 16:54:04 -0400 Received: by mail-yb1-f202.google.com with SMTP id y3so3257541ybg.12 for ; Wed, 22 May 2019 13:54:03 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20161025; h=date:in-reply-to:message-id:mime-version:references:subject:from:to :cc; bh=QY9qWZ3WpI+bDR3XH+UhavkeFdxps5N78C1PHSmhgK0=; b=AVOGP9LV/N+ZVWHDWD0mSzFZrmwTYPQ7SLzywYWeUu/GZc+4zJe4tQA2SfEKa9JljB +oWxxDm5d7bIVS9H8MaAKDtwaVGXS7+vi/zJaRyWbla1vl0ylZCAhHbP7rdmpu2l1N47 L0+3FDI3KaHhS6czKzBWyWS+5wNxrCaG1T9uyO5h9PZigO6/igV/q7507yzvKaudec4z IWmhfwdskvnEJNz8X89Lm4Z8UEaK1kHdEortE26pfmoCScFxjXYyse83itDwa8J9ChQS 9Fam8VCPUfBaV+t98mUtkURbHGT9mYGb5lXoV9ReUge8QXGKP9rtGXkNkR3nmymDUMyw 7qrg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:date:in-reply-to:message-id:mime-version :references:subject:from:to:cc; bh=QY9qWZ3WpI+bDR3XH+UhavkeFdxps5N78C1PHSmhgK0=; b=M11ilTpY2vknX0FgwSRZb0RSHUeomK0aDD0T/6SFhv2fdtI80HecFUp1cC80+Q5zwa ysGkL3/+7yyMP5ArcsVLmI+kSG4TTlh9LVE2dI62U2pLyx2aesW/zwUe3U6R/jzSSvQW FMB7nNxYRmTSsOyPzoxiAty7q7xhUflFPeGS4lU40gcQE1q/aopxlMa0/zYmBmxAadK0 6WQi1RvRcBrO0CYxNcXQ6/HbDO1kEFy1mV8bJFiJS5vCwPQkS/0+l0POEnOq9MAHiu/o 0Ej0pn2V19yUhRoeWdStYAJPIr0m0tEDW4lIpDHca7NUFK/cGoo6mp07AVjaC51uKrWw E77A== X-Gm-Message-State: APjAAAUmTulxjnUghes9G1rPttv5Hf+JL4idlY97QERxKbakq4GR0QbY gXGQk2HOTDcVQ2xUt4kjHLSukyw= X-Google-Smtp-Source: APXvYqwSnafodNT/CMgErqLqyBdVSTztpb4cK0Vtne4k1bgBpFEQfNvAF1TAttpDOdd67zwvEN8Jg/Y= X-Received: by 2002:a81:1e15:: with SMTP id e21mr20744303ywe.200.1558558443387; Wed, 22 May 2019 13:54:03 -0700 (PDT) Date: Wed, 22 May 2019 13:53:53 -0700 In-Reply-To: <20190522205353.140648-1-sdf@google.com> Message-Id: <20190522205353.140648-4-sdf@google.com> Mime-Version: 1.0 References: <20190522205353.140648-1-sdf@google.com> X-Mailer: git-send-email 2.21.0.1020.gf2820cf01a-goog Subject: [PATCH bpf-next v2 4/4] bpf: tracing: properly use bpf_prog_array api From: Stanislav Fomichev To: netdev@vger.kernel.org, bpf@vger.kernel.org Cc: davem@davemloft.net, ast@kernel.org, daniel@iogearbox.net, Stanislav Fomichev , Steven Rostedt , Ingo Molnar Content-Type: text/plain; charset="UTF-8" Sender: bpf-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: bpf@vger.kernel.org Now that we don't have __rcu markers on the bpf_prog_array helpers, let's use proper rcu_dereference_protected to obtain array pointer under mutex. Cc: Steven Rostedt Cc: Ingo Molnar Signed-off-by: Stanislav Fomichev --- kernel/trace/bpf_trace.c | 18 ++++++++++-------- 1 file changed, 10 insertions(+), 8 deletions(-) diff --git a/kernel/trace/bpf_trace.c b/kernel/trace/bpf_trace.c index f92d6ad5e080..766e42730318 100644 --- a/kernel/trace/bpf_trace.c +++ b/kernel/trace/bpf_trace.c @@ -19,6 +19,9 @@ #include "trace_probe.h" #include "trace.h" +#define bpf_event_rcu_dereference(p) \ + rcu_dereference_protected(p, lockdep_is_held(&bpf_event_mutex)) + #ifdef CONFIG_MODULES struct bpf_trace_module { struct module *module; @@ -1034,7 +1037,7 @@ static DEFINE_MUTEX(bpf_event_mutex); int perf_event_attach_bpf_prog(struct perf_event *event, struct bpf_prog *prog) { - struct bpf_prog_array __rcu *old_array; + struct bpf_prog_array *old_array; struct bpf_prog_array *new_array; int ret = -EEXIST; @@ -1052,7 +1055,7 @@ int perf_event_attach_bpf_prog(struct perf_event *event, if (event->prog) goto unlock; - old_array = event->tp_event->prog_array; + old_array = bpf_event_rcu_dereference(event->tp_event->prog_array); if (old_array && bpf_prog_array_length(old_array) >= BPF_TRACE_MAX_PROGS) { ret = -E2BIG; @@ -1075,7 +1078,7 @@ int perf_event_attach_bpf_prog(struct perf_event *event, void perf_event_detach_bpf_prog(struct perf_event *event) { - struct bpf_prog_array __rcu *old_array; + struct bpf_prog_array *old_array; struct bpf_prog_array *new_array; int ret; @@ -1084,7 +1087,7 @@ void perf_event_detach_bpf_prog(struct perf_event *event) if (!event->prog) goto unlock; - old_array = event->tp_event->prog_array; + old_array = bpf_event_rcu_dereference(event->tp_event->prog_array); ret = bpf_prog_array_copy(old_array, event->prog, NULL, &new_array); if (ret == -ENOENT) goto unlock; @@ -1106,6 +1109,7 @@ int perf_event_query_prog_array(struct perf_event *event, void __user *info) { struct perf_event_query_bpf __user *uquery = info; struct perf_event_query_bpf query = {}; + struct bpf_prog_array *progs; u32 *ids, prog_cnt, ids_len; int ret; @@ -1130,10 +1134,8 @@ int perf_event_query_prog_array(struct perf_event *event, void __user *info) */ mutex_lock(&bpf_event_mutex); - ret = bpf_prog_array_copy_info(event->tp_event->prog_array, - ids, - ids_len, - &prog_cnt); + progs = bpf_event_rcu_dereference(event->tp_event->prog_array); + ret = bpf_prog_array_copy_info(progs, ids, ids_len, &prog_cnt); mutex_unlock(&bpf_event_mutex); if (copy_to_user(&uquery->prog_cnt, &prog_cnt, sizeof(prog_cnt)) || -- 2.21.0.1020.gf2820cf01a-goog