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 vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id ADFFBC433F5 for ; Thu, 21 Apr 2022 20:11:44 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1392249AbiDUUOc (ORCPT ); Thu, 21 Apr 2022 16:14:32 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:39134 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232966AbiDUUO0 (ORCPT ); Thu, 21 Apr 2022 16:14:26 -0400 Received: from mail-pf1-x449.google.com (mail-pf1-x449.google.com [IPv6:2607:f8b0:4864:20::449]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id B92A763C8 for ; Thu, 21 Apr 2022 13:11:35 -0700 (PDT) Received: by mail-pf1-x449.google.com with SMTP id b12-20020aa7870c000000b0050c7c7f0245so884949pfo.15 for ; Thu, 21 Apr 2022 13:11:35 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20210112; h=date:message-id:mime-version:subject:from:to:cc; bh=xl86mN30osJz9axtr4HGKyAY6n8mDzLbZshrFbw38w0=; b=gFkWCHa0kM5FoJwOLehhGiuzSVMGJFSP6kpu5y/jfku9ja7w/KaVHxwr7SiVN7dhFO TXcrvIApr+h5KMnT2X5rpNveSJ6aHKpjUvDM3w79BsZcM2ru/CGt14N3SsqsaYPgjt/e CZJdiFv/XNMSBdAvQMT3hisULGE/bSJbkU+TCDUV+yWaEl1yotxLjNG0psnSxzUAZq5V uufSROGLvdW6S9kxg8WdJdZwW+jaKUJ7nGD0pDRdz7J/uhOiiOznfNi5OkTLPxdEYA55 gxWqgGgIPlT2kwSvHimP3dM8Y1cDh09Qm5Q7FUH6xOg02fuLdsIhmDoS5twaC/e8fq42 yyPQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:date:message-id:mime-version:subject:from:to:cc; bh=xl86mN30osJz9axtr4HGKyAY6n8mDzLbZshrFbw38w0=; b=XPhRJ603zCLKnTgkkE/hsQXAvx+xHQxJe7JP4AuwUHjGGmSVpaSdKJSO/CgyypMKc8 IZYjQw6mkEoCX/bcvz+7nY26G0KzhzUqzwE1WXp7k7D8Xd3drJWsBA6Mc/Aq1z8/yC7X 77FuTjh0tSVG8BoqVDLq9DyzLv39uV3COahA/jQy68ZaMXqBaeB1HeuPfYe/QcseF2FI ST/z/Ccd6p2gQr6plONEJvs0xKGJ5mI072gkbQHXLHGIZwlyg7VQiHrSCG0gYG6nFfWI T/xQN/Rbx2WjiNSTKKm3X0AcJgCkW96gcLgUz3a1G9bNzIp3fKjIgJxTDplpRMlpH6ni wDkA== X-Gm-Message-State: AOAM533URawFqR/tlpOvP9SgLKTXJeSNVhKRLROdDz+Aq88Lj3LTpkUg TuzAhgBajnzUTKwKC3fvzCuUqYOEVtXo X-Google-Smtp-Source: ABdhPJxyvpg4HtUlA89af+J7Dme3WMKLPbKVtxgtzLdRK7v4TUf4kWl54uuECS4cN+EmT6zJ1xdxlQoD39xX X-Received: from connoro.c.googlers.com ([fda3:e722:ac3:cc00:7f:e700:c0a8:a99]) (user=connoro job=sendgmr) by 2002:a17:902:f605:b0:14d:9e11:c864 with SMTP id n5-20020a170902f60500b0014d9e11c864mr1097012plg.54.1650571895188; Thu, 21 Apr 2022 13:11:35 -0700 (PDT) Date: Thu, 21 Apr 2022 20:11:25 +0000 Message-Id: <20220421201125.13907-1-connoro@google.com> Mime-Version: 1.0 X-Mailer: git-send-email 2.36.0.rc2.479.g8af0fa9b8e-goog Subject: [PATCH bpf-next] libbpf: also check /sys/kernel/tracing for tracefs files From: "Connor O'Brien" To: Alexei Starovoitov , Daniel Borkmann , Andrii Nakryiko Cc: Martin KaFai Lau , Song Liu , Yonghong Song , John Fastabend , KP Singh , netdev@vger.kernel.org, bpf@vger.kernel.org, linux-kernel@vger.kernel.org, "Connor O'Brien" Content-Type: text/plain; charset="UTF-8" Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org libbpf looks for tracefs files only under debugfs, but tracefs may be mounted even if debugfs is not. When /sys/kernel/debug/tracing is absent, try looking under /sys/kernel/tracing instead. Signed-off-by: Connor O'Brien --- tools/lib/bpf/libbpf.c | 26 +++++++++++++++++++------- 1 file changed, 19 insertions(+), 7 deletions(-) diff --git a/tools/lib/bpf/libbpf.c b/tools/lib/bpf/libbpf.c index 68cc134d070d..6ef587329eb2 100644 --- a/tools/lib/bpf/libbpf.c +++ b/tools/lib/bpf/libbpf.c @@ -10140,10 +10140,16 @@ static void gen_kprobe_legacy_event_name(char *buf, size_t buf_sz, __sync_fetch_and_add(&index, 1)); } +static bool debugfs_available(void) +{ + return !access("/sys/kernel/debug/tracing", F_OK); +} + static int add_kprobe_event_legacy(const char *probe_name, bool retprobe, const char *kfunc_name, size_t offset) { - const char *file = "/sys/kernel/debug/tracing/kprobe_events"; + const char *file = debugfs_available() ? "/sys/kernel/debug/tracing/kprobe_events" : + "/sys/kernel/tracing/kprobe_events"; return append_to_file(file, "%c:%s/%s %s+0x%zx", retprobe ? 'r' : 'p', @@ -10153,7 +10159,8 @@ static int add_kprobe_event_legacy(const char *probe_name, bool retprobe, static int remove_kprobe_event_legacy(const char *probe_name, bool retprobe) { - const char *file = "/sys/kernel/debug/tracing/kprobe_events"; + const char *file = debugfs_available() ? "/sys/kernel/debug/tracing/kprobe_events" : + "/sys/kernel/tracing/kprobe_events"; return append_to_file(file, "-:%s/%s", retprobe ? "kretprobes" : "kprobes", probe_name); } @@ -10163,7 +10170,8 @@ static int determine_kprobe_perf_type_legacy(const char *probe_name, bool retpro char file[256]; snprintf(file, sizeof(file), - "/sys/kernel/debug/tracing/events/%s/%s/id", + debugfs_available() ? "/sys/kernel/debug/tracing/events/%s/%s/id" : + "/sys/kernel/tracing/events/%s/%s/id", retprobe ? "kretprobes" : "kprobes", probe_name); return parse_uint_from_file(file, "%d\n"); @@ -10493,7 +10501,8 @@ static void gen_uprobe_legacy_event_name(char *buf, size_t buf_sz, static inline int add_uprobe_event_legacy(const char *probe_name, bool retprobe, const char *binary_path, size_t offset) { - const char *file = "/sys/kernel/debug/tracing/uprobe_events"; + const char *file = debugfs_available() ? "/sys/kernel/debug/tracing/uprobe_events" : + "/sys/kernel/tracing/uprobe_events"; return append_to_file(file, "%c:%s/%s %s:0x%zx", retprobe ? 'r' : 'p', @@ -10503,7 +10512,8 @@ static inline int add_uprobe_event_legacy(const char *probe_name, bool retprobe, static inline int remove_uprobe_event_legacy(const char *probe_name, bool retprobe) { - const char *file = "/sys/kernel/debug/tracing/uprobe_events"; + const char *file = debugfs_available() ? "/sys/kernel/debug/tracing/uprobe_events" : + "/sys/kernel/tracing/uprobe_events"; return append_to_file(file, "-:%s/%s", retprobe ? "uretprobes" : "uprobes", probe_name); } @@ -10513,7 +10523,8 @@ static int determine_uprobe_perf_type_legacy(const char *probe_name, bool retpro char file[512]; snprintf(file, sizeof(file), - "/sys/kernel/debug/tracing/events/%s/%s/id", + debugfs_available() ? "/sys/kernel/debug/tracing/events/%s/%s/id" : + "/sys/kernel/tracing/events/%s/%s/id", retprobe ? "uretprobes" : "uprobes", probe_name); return parse_uint_from_file(file, "%d\n"); @@ -11071,7 +11082,8 @@ static int determine_tracepoint_id(const char *tp_category, int ret; ret = snprintf(file, sizeof(file), - "/sys/kernel/debug/tracing/events/%s/%s/id", + debugfs_available() ? "/sys/kernel/debug/tracing/events/%s/%s/id" : + "/sys/kernel/tracing/events/%s/%s/id", tp_category, tp_name); if (ret < 0) return -errno; -- 2.36.0.rc2.479.g8af0fa9b8e-goog