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=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI, SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,T_DKIMWL_WL_MED,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 B2DBDC04E84 for ; Tue, 28 May 2019 18:29:59 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 90A32208CB for ; Tue, 28 May 2019 18:29:59 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b="jrHoidhN" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728170AbfE1S36 (ORCPT ); Tue, 28 May 2019 14:29:58 -0400 Received: from mail-yb1-f202.google.com ([209.85.219.202]:38821 "EHLO mail-yb1-f202.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728161AbfE1S35 (ORCPT ); Tue, 28 May 2019 14:29:57 -0400 Received: by mail-yb1-f202.google.com with SMTP id a13so19164876ybm.5 for ; Tue, 28 May 2019 11:29:57 -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=Sdrk7zv1q4sBRbvsm6ygjzJAHzpOvMNms+yuTgEQ42g=; b=jrHoidhNgoB65HMHvIopYGUiXI8FZgMqt3PMqVeae8wK2btEBVjehb50C2tbD8wo8X a4+UZ1An+r+M3VOXdtZKNRQt4XG5JtNHjBwU/pfXZiJx8y5H/1xDt7mVjYO8xCfaUdrp iC4t7HIZuZjU6UeigxT5KtPWWeQYwJyDRS0W20X1mr/jwtVUI9mqRo7KkYIz6poCMzIN WXjnzrsXOpu4j/Ty5wCEkdZhfput0I7oFNNHIEZEUpybmpP3CqvORmksSgkdIRsV71xH nJcd19wokFq+nndgRp2+PRpxJt9FBMZZpSKbiQoQf75GsFL5FUyFFT0KtOKA+YzRjLka BRfA== 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=Sdrk7zv1q4sBRbvsm6ygjzJAHzpOvMNms+yuTgEQ42g=; b=kHADRmnWJB6Fg7YEgZglkyB5A9bJ/FIo8vgI/ligVnqy0AGu8FNIE0xd+H+lD177UF H4a6EtalMvklnbDgv6EkkTbArW+tgG6YfWxtTiiNufkqOiMkdXbJWSfKEP4KFOYt+3xd ZmexumxofSL9qeFcjiQi5W3716rZv7SfNRAxvODTNrqf5/G2bwKqDHzC1AfvVLaJxIZA NvuBl6Z0BMXOKMb5n6CUCqOrdpgjUAxozdG6KJnALBc4HSaHX7TXfmVBXCFVcUfRg0Sn bXGoEtdngO6RbWzQZkXQOnCV5CWoc1/3+6BMNn+hs2IRDCXCh/0sQZ9OFcEjS45hG8Mq guXA== X-Gm-Message-State: APjAAAUyVZ4mIyQuWUjsFkJln9NcrsaRZHkliOixswfG5BklbvQGVlhV KEJhz8UEJEBWGoDvoUaopYuNxcwm8uGBIQaIfqcz1tNXOaNxM5l1IxC5Pp1PiloTkMvnoByGdlK kJfDRJXbYel2Z/SPcNoFjLmHcA9Ra4SHAYm/0VJm213fOGJvQnx4ukA== X-Google-Smtp-Source: APXvYqxaFrOQsOMYSkwDJahY1PY/8v7Ge4VXn2Gmx/1WDmO90lXjEJ3x1JTnl0DUUrSJ1qd6msGec5A= X-Received: by 2002:a0d:fcc7:: with SMTP id m190mr8070407ywf.60.1559068196801; Tue, 28 May 2019 11:29:56 -0700 (PDT) Date: Tue, 28 May 2019 11:29:46 -0700 In-Reply-To: <20190528182946.3633-1-sdf@google.com> Message-Id: <20190528182946.3633-4-sdf@google.com> Mime-Version: 1.0 References: <20190528182946.3633-1-sdf@google.com> X-Mailer: git-send-email 2.22.0.rc1.257.g3120a18244-goog Subject: [PATCH bpf-next v3 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: netdev-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: netdev@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 fe73926a07cd..3994a231eb92 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; @@ -1099,7 +1102,7 @@ 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; @@ -1117,7 +1120,7 @@ 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; @@ -1140,7 +1143,7 @@ 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; @@ -1149,7 +1152,7 @@ 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; @@ -1171,6 +1174,7 @@ 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; @@ -1195,10 +1199,8 @@ 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)) || -- 2.22.0.rc1.257.g3120a18244-goog