From patchwork Fri Feb 2 18:44:45 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Beau Belgrave X-Patchwork-Id: 19864 Return-Path: Delivered-To: ouuuleilei@gmail.com Received: by 2002:a05:7301:9bc1:b0:106:209c:c626 with SMTP id op1csp643393dyc; Fri, 2 Feb 2024 11:10:30 -0800 (PST) X-Google-Smtp-Source: AGHT+IGC4s7PWFiXIfrGHz+1cYILkcj5ReFo2CFzABt8Z6mY1NEqRO6wGwROqIpqG+pOa4bh9l0q X-Received: by 2002:aa7:9dc5:0:b0:6dd:dd42:bdef with SMTP id g5-20020aa79dc5000000b006dddd42bdefmr2798323pfq.30.1706901030759; Fri, 02 Feb 2024 11:10:30 -0800 (PST) ARC-Seal: i=2; a=rsa-sha256; t=1706901030; cv=pass; d=google.com; s=arc-20160816; b=hBCmzsMz9z8YRH2lJJ8GrsiDcQJ1RmLblw2kE1xUspRBDdgei9rl8QBGUPZTmivOFH 7G1pdQ8XvXpxc1n//gk1iRZPE4OWMzcECl/FH47UcPGVs8003mBzX5mB4xLuL1m9l25y jGhlz7Twutcz7ifOI59yTuoTaTWPBJYLILIEmgVoKfYlH0NgSGueigpWzLs0FTh39Wfc NrDc8LbsLsikNhTdAZ3HNatUTgqrtRmUszLKgWZ3Qw5ptOXeaJVPjJcJbdhxvFkP6Nqp hV6TNpTLCJXI6LUgqswVKdV4KnY+kNAGjCcz6J48FXmwPAHod65+xAFGFrNqjNLjp6Xe jq5g== ARC-Message-Signature: i=2; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=arc-20160816; h=content-transfer-encoding:mime-version:list-unsubscribe :list-subscribe:list-id:precedence:message-id:date:subject:cc:to :from:dkim-signature:dkim-filter; bh=48MWZE2UYPXR09piVcxgKgUazOGoiw/j3+WKWE+SLDQ=; fh=x7jSyIn5L58tWXRW5rHuuLVHIC+xJS3Hy7AIl7uzx9w=; b=lAWoMu7sekORmBcWHoy5I8X9XlU6oBAj0OG+S8u197RB2e11cMBR4uvLESBBlRU0J3 YDsRZUyXKqwbrUYVkjrL83g/xIW16YPn2nqSPe2dduUfIAjE5T4N0e+zU1Q9RrlrIO1x WWwQ3MXrQpL6aeETNWbw8on4JHDgXZgyOglOsHJ5MZISoec+G3ZybncUdonJxcfgWTgZ 5SXSUI5m5vgeDxKo0+zGSrI9nFkHWmEb+ZXSXboqrAtzn12hoijsT49fn0OX31uWkMIA vQFOemizKcCN2Z2r6ciaJEU11x49LP5+W26m2MZrc7LW0Ib+kD5JqlC/Ecap86uQoyJ9 q3Sg==; dara=google.com ARC-Authentication-Results: i=2; mx.google.com; dkim=pass header.i=@linux.microsoft.com header.s=default header.b=H9919c1k; arc=pass (i=1 spf=pass spfdomain=linux.microsoft.com dkim=pass dkdomain=linux.microsoft.com dmarc=pass fromdomain=linux.microsoft.com); spf=pass (google.com: domain of linux-kernel+bounces-50440-ouuuleilei=gmail.com@vger.kernel.org designates 139.178.88.99 as permitted sender) smtp.mailfrom="linux-kernel+bounces-50440-ouuuleilei=gmail.com@vger.kernel.org"; dmarc=pass (p=NONE sp=NONE dis=NONE) header.from=linux.microsoft.com X-Forwarded-Encrypted: i=1; AJvYcCX66jdcTDzKztXSjoTmlCWYiTr+9VjPCppj1Exek/IcYc05AsuOlW6BFDu3spdnMCB2YM4X+yjDV6QqE4DHFpyl0kfPNw== Received: from sv.mirrors.kernel.org (sv.mirrors.kernel.org. [139.178.88.99]) by mx.google.com with ESMTPS id m9-20020a056a00080900b006ddc403e5b1si1949262pfk.272.2024.02.02.11.10.30 for (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Fri, 02 Feb 2024 11:10:30 -0800 (PST) Received-SPF: pass (google.com: domain of linux-kernel+bounces-50440-ouuuleilei=gmail.com@vger.kernel.org designates 139.178.88.99 as permitted sender) client-ip=139.178.88.99; Authentication-Results: mx.google.com; dkim=pass header.i=@linux.microsoft.com header.s=default header.b=H9919c1k; arc=pass (i=1 spf=pass spfdomain=linux.microsoft.com dkim=pass dkdomain=linux.microsoft.com dmarc=pass fromdomain=linux.microsoft.com); spf=pass (google.com: domain of linux-kernel+bounces-50440-ouuuleilei=gmail.com@vger.kernel.org designates 139.178.88.99 as permitted sender) smtp.mailfrom="linux-kernel+bounces-50440-ouuuleilei=gmail.com@vger.kernel.org"; dmarc=pass (p=NONE sp=NONE dis=NONE) header.from=linux.microsoft.com Received: from smtp.subspace.kernel.org (wormhole.subspace.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by sv.mirrors.kernel.org (Postfix) with ESMTPS id 69AE5293C12 for ; Fri, 2 Feb 2024 19:05:08 +0000 (UTC) Received: from localhost.localdomain (localhost.localdomain [127.0.0.1]) by smtp.subspace.kernel.org (Postfix) with ESMTP id 64DB083A06; Fri, 2 Feb 2024 18:45:04 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linux.microsoft.com header.i=@linux.microsoft.com header.b="H9919c1k" Received: from linux.microsoft.com (linux.microsoft.com [13.77.154.182]) by smtp.subspace.kernel.org (Postfix) with ESMTP id E05D58063E; Fri, 2 Feb 2024 18:44:59 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=13.77.154.182 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1706899501; cv=none; b=iOAMKoQhpeO06nKCRlK+xwQDf+YG+VZCTCdlOQD8r8O08w0N0e0Cur+Dv6GaCHk5N1IfkT82iNDvRlu1NlieS8EHLAJtQOGsS8460DFjsXDbAWca2UzF81y94UkLY2hYfk6igG5RrazExw+2ra/SJviq9f4m99Gbv1FgaMamP1k= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1706899501; c=relaxed/simple; bh=pmKB4eIe2cyRrYdX+1cbU2atDrbrBb75iAXm274H9B4=; h=From:To:Cc:Subject:Date:Message-Id:MIME-Version; b=usFI74cqxavUTeqaD8WPt//DqrjvGDSZjN3TrzXdg7DLLzO8GYllNRtrplGi00REA14OY0igI6rTYmK5efomuyS8tV56mKg0NzNfbSnqGLy/Zjj7nbPKj3wjWjvyq06XpvIF4sMtOf/WEXIngWdib/uhH4I7Y/anvHj5I2qlpdo= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.microsoft.com; spf=pass smtp.mailfrom=linux.microsoft.com; dkim=pass (1024-bit key) header.d=linux.microsoft.com header.i=@linux.microsoft.com header.b=H9919c1k; arc=none smtp.client-ip=13.77.154.182 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.microsoft.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=linux.microsoft.com Received: from localhost.localdomain (unknown [4.155.48.115]) by linux.microsoft.com (Postfix) with ESMTPSA id 8987120B2000; Fri, 2 Feb 2024 10:44:58 -0800 (PST) DKIM-Filter: OpenDKIM Filter v2.11.0 linux.microsoft.com 8987120B2000 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux.microsoft.com; s=default; t=1706899498; bh=48MWZE2UYPXR09piVcxgKgUazOGoiw/j3+WKWE+SLDQ=; h=From:To:Cc:Subject:Date:From; b=H9919c1krN3yFShbS3oFr6BFpRZlbQyUd2KqJF+tbrZoC0BtIKW8SwOz4hFRpgVO6 PMT3L4m4+de2NPtV4lWI+UzZ2RtxHHlwC7PxEPSpIwgqa1yEqIGbkFA6nriZJ1mh5I cwm2qAzNJy0pPHJD8qs3HusCmYwywXN/fo0k/2bE= From: Beau Belgrave To: rostedt@goodmis.org, mhiramat@kernel.org Cc: linux-kernel@vger.kernel.org, linux-trace-kernel@vger.kernel.org, mathieu.desnoyers@efficios.com Subject: [PATCH v2 0/4] tracing/user_events: Introduce multi-format events Date: Fri, 2 Feb 2024 18:44:45 +0000 Message-Id: <20240202184449.1674-1-beaub@linux.microsoft.com> X-Mailer: git-send-email 2.34.1 Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-getmail-retrieved-from-mailbox: INBOX X-GMAIL-THRID: 1789815162276059856 X-GMAIL-MSGID: 1789815455166913752 Currently user_events supports 1 event with the same name and must have the exact same format when referenced by multiple programs. This opens an opportunity for malicous or poorly thought through programs to create events that others use with different formats. Another scenario is user programs wishing to use the same event name but add more fields later when the software updates. Various versions of a program may be running side-by-side, which is prevented by the current single format requirement. Add a new register flag (USER_EVENT_REG_MULTI_FORMAT) which indicates the user program wishes to use the same user_event name, but may have several different formats of the event in the future. When this flag is used, create the underlying tracepoint backing the user_event with a unique name per-version of the format. It's important that existing ABI users do not get this logic automatically, even if one of the multi format events matches the format. This ensures existing programs that create events and assume the tracepoint name will match exactly continue to work as expected. Add logic to only check multi-format events with other multi-format events and single-format events to only check single-format events during find. Change system name of the multi-format event tracepoint to ensure that multi-format events are isolated completely from single-format events. This prevents single-format names from conflicting with multi-format events if they end with the same suffix as the multi-format events. Add a register_name (reg_name) to the user_event struct which allows for split naming of events. We now have the name that was used to register within user_events as well as the unique name for the tracepoint. Upon registering events ensure matches based on first the reg_name, followed by the fields and format of the event. This allows for multiple events with the same registered name to have different formats. The underlying tracepoint will have a unique name in the format of {reg_name}.{unique_id}. For example, if both "test u32 value" and "test u64 value" are used with the USER_EVENT_REG_MULTI_FORMAT the system would have 2 unique tracepoints. The dynamic_events file would then show the following: u:test u64 count u:test u32 count The actual tracepoint names look like this: test.0 test.1 Both would be under the new user_events_multi system name to prevent the older ABI from being used to squat on multi-formatted events and block their use. Deleting events via "!u:test u64 count" would only delete the first tracepoint that matched that format. When the delete ABI is used all events with the same name will be attempted to be deleted. If per-version deletion is required, user programs should either not use persistent events or delete them via dynamic_events. Changes in v2: Tracepoint names changed from "name:[id]" to "name.id". Feedback was the : could conflict with system name formats. []'s are also special characters for bash. Updated self-test and docs to reflect the new suffix format. Updated docs to include a regex example to help guide recording programs find the correct event in ambiguous cases. Beau Belgrave (4): tracing/user_events: Prepare find/delete for same name events tracing/user_events: Introduce multi-format events selftests/user_events: Test multi-format events tracing/user_events: Document multi-format flag Documentation/trace/user_events.rst | 27 ++- include/uapi/linux/user_events.h | 6 +- kernel/trace/trace_events_user.c | 224 +++++++++++++----- .../testing/selftests/user_events/abi_test.c | 134 +++++++++++ 4 files changed, 329 insertions(+), 62 deletions(-) base-commit: 610a9b8f49fbcf1100716370d3b5f6f884a2835a