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 lists.lttng.org (lists.lttng.org [167.114.26.123]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 475C6D5AE71 for ; Thu, 7 Nov 2024 08:03:23 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=lists.lttng.org; s=default; t=1730966601; bh=xj/X9s+k5ALNRwPCk6le3HOINroP4nrEUBbsPKD9G4A=; h=Date:Subject:To:List-Id:List-Unsubscribe:List-Archive:List-Post: List-Help:List-Subscribe:From:Reply-To:From; b=FzYHJVm3ZrUFYdcqZGa3GMw8hIuh4pkXi/Tlwwn69T1QFq71P1VCGiVt/N0RxO3M6 1+c173vALzw707GxK59GR45Ns8egr6ooe5FTDviebkt331RNvjtbIa840HcNiKTwij ZZ58nyNHU3/txjqf40a+cqd9Ep8+ghSoO7cGWTZhYCCBVtTrkIAFfT9GAor7Nm5bqK +rr+4LXxaML5mIugkB8DbtlGwRVcvct3PIuxua3kGWTDWfDAwszSFzSXPY3l5ckT1H +HAMIOh8VuAn45uwKTTtwyWZLu5o068Y6Ao91+fNaoaZ/UDlCkgXppadIQXBk0aYg3 NsaIap+kpIDLg== Received: from lists-lttng01.efficios.com (localhost [IPv6:::1]) by lists.lttng.org (Postfix) with ESMTP id 4XkZMF12lVz1d6p; Thu, 7 Nov 2024 03:03:21 -0500 (EST) Received: from mail-ej1-x62b.google.com (mail-ej1-x62b.google.com [IPv6:2a00:1450:4864:20::62b]) by lists.lttng.org (Postfix) with ESMTPS id 4XkZMB6jVPz1cwN for ; Thu, 7 Nov 2024 03:03:18 -0500 (EST) Received: by mail-ej1-x62b.google.com with SMTP id a640c23a62f3a-a9ed7d8c86cso95116866b.2 for ; Thu, 07 Nov 2024 00:03:18 -0800 (PST) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1730966597; x=1731571397; h=to:subject:message-id:date:from:mime-version:x-gm-message-state :from:to:cc:subject:date:message-id:reply-to; bh=rxh8OOnbyBPMSlQwzeVL/40fkSzeqgHAAp17RLUAWfQ=; b=pmvATylCy+V1MDFDuqfpR8+z08mE1lIKUz2qiopHNwS0pMgAczpEvIvZ9PgRUDN75S KBAb8mAyzmXInuQsbCTzgp/wpC+JU7Q4MCXdx8feMcaqqmM71aijkNaz0c2Ptvyd5wHv 2vV49e1y48DHEG6WrK2GSaJK2evuTW6wl/0pKcjPtVZD1kcO6yJQ6JWU3F09A0IkH/6V ff0Zay0Z/Bz7g8ribDjQ1HjU1mLOJB/HVxqtU6Dsf63SrQoXHYWNFmZ4AsUtkZMDp6aB HocXMklkeHsPibB+dz35y7bf9O4hGcxr3oTmBvzOEuUjmXObw8o4JhcgAmT+p3nmVtSb fglQ== X-Gm-Message-State: AOJu0YzNAB0fZIc+iRmWSYzh9tyOdPIAo8+AfYHdV+r4usN6FgL4s4wI Ao0FkwdrN5QpL6u3G7+y2H2172SUi9Awo6ALk/6m8QzKGhGISllreeZsKmp3otKpG6I/94rb6St veTKK/gHZoPn4vQnhUzfzBSnEp2lKD88G X-Google-Smtp-Source: AGHT+IGZdlNHKQEzOfFWmZdwbs2uJIyknsteLvy5o0vm7rCfTva56pJgMRW8atseG8DRt0abAI8oFbaUrkN0UPiZE9w= X-Received: by 2002:a17:907:6e9e:b0:a9e:e1a9:8df0 with SMTP id a640c23a62f3a-a9ee74d35e7mr2467166b.29.1730966597314; Thu, 07 Nov 2024 00:03:17 -0800 (PST) MIME-Version: 1.0 Date: Thu, 7 Nov 2024 09:03:06 +0100 Message-ID: Subject: Kernel tracing from inside a Docker container To: lttng-dev@lists.lttng.org Content-Type: text/plain; charset="UTF-8" X-BeenThere: lttng-dev@lists.lttng.org X-Mailman-Version: 2.1.39 Precedence: list List-Id: LTTng development list List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , From: Dirk Eibach via lttng-dev Reply-To: Dirk Eibach Errors-To: lttng-dev-bounces@lists.lttng.org Sender: "lttng-dev" Hi, sorry, Outlook is messing up my plaintext mails, so I am switching to my gmail account. > lttng-modules exposes its control ABI through the virtual file /proc/lttng. > > Does you container have access to that file ? The container is running in privileged mode. root@9348eb19e6f4:/# ls -l /proc/lttng -rw------- 1 root root 0 Nov 6 16:05 /proc/lttng > Note that if you give access to that file within the container, then the container > can observe detailed information about kernel internals (including related to > other containers). This is a development-only system, so the security implications are acceptable. I have observed one more thing. When I start the session daemon with the -vvv option I get: root@9348eb19e6f4:/# lttng list --kernel DBG1 - 07:31:23.811796947 [Client management]: Wait for client response (in thread_manage_clients() at client.c:2576) DBG1 - 07:31:23.811867247 [Client management]: Receiving data from client ... (in thread_manage_clients() at client.c:2604) DBG1 - 07:31:23.811945247 [Client management]: Processing client command 'LTTNG_LIST_TRACEPOINTS' (14) (in process_client_msg() at client.c:1016) Error: Failed to load kmod library resources Warning: No kernel tracer available DBG1 - 07:31:23.812076447 [Client management]: Missing llm header, creating one. (in process_client_msg() at client.c:2381) DBG1 - 07:31:23.812085547 [Client management]: Sending response (size: 24, retcode: Kernel tracer not available (33)) (in thread_manage_clients() at client.c:2683) DBG1 - 07:31:23.812156547 [Client management]: Accepting client command ... (in thread_manage_clients() at client.c:2534) Error: Unable to list kernel events: Kernel tracer not available Regards Dirk