From patchwork Mon Oct 2 20:25:30 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Mathieu Desnoyers X-Patchwork-Id: 147558 Return-Path: Delivered-To: ouuuleilei@gmail.com Received: by 2002:a05:612c:2a8e:b0:403:3b70:6f57 with SMTP id in14csp1734833vqb; Mon, 2 Oct 2023 15:50:56 -0700 (PDT) X-Google-Smtp-Source: AGHT+IGqAXa4uVYG8QNT3tCi17WZrV8GZUnIIBj3HWndQpZ74T3pHQ18e6CSYmg8kRT9q/EAzq2I X-Received: by 2002:a05:6102:185:b0:452:bf74:bcec with SMTP id r5-20020a056102018500b00452bf74bcecmr11329904vsq.10.1696287056649; Mon, 02 Oct 2023 15:50:56 -0700 (PDT) ARC-Seal: i=1; a=rsa-sha256; t=1696287056; cv=none; d=google.com; s=arc-20160816; b=WzraQgcBwPIAAYwkOUEfTk9jPIq22aK5s2M7girH7fUlqhaWWJVzULrmMwApKDkcUF SsJSHqaTzPqZYORhjSmfCKQnR2OU3Y/9pkLimzOEkRHSuy+XKFBO6f/w2pGFzwdKdYaF D/DuBqTikXmCaEasdbzgfMytXQ39/E52/hKGSFau9ZN4Z+16rCwZG6MC0fJ09cOfhgwT Cx3ZO7GT9PeyKfA+9nWc/kuX0OJxTlUJEZEDan2ZWg9gEFIk58kCYuulogPCxbE4+991 7cot0xiDLMLrY33D+4sAvHHyW5HwdqdDyqCDqPBpFnrxNzwOhjyEg3SCbafZvwjF6qz/ 9rJg== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=arc-20160816; h=list-id:precedence:content-transfer-encoding:mime-version :references:in-reply-to:message-id:date:subject:cc:to:from :dkim-signature; bh=+FDEKUYWY06MJfRWg/iuySi4MVRBDqWW7n9alYF7crY=; fh=185gnY/jvZ3KyhWEGKx2Ja9SQMRN/yWtD8bZTRNPBJo=; b=A664LiMsf5k3nzWRep6hjCF2z96c8cOxIerQEzc8asEeoMxCfk0zJgGIOz2NSCU4+H 5niHskukHDDhpGAfX5/zQpYmXrIwnVncvEhlvWUML5R0FuAi7Jb7I/Fc8COk/VwTh9W/ GI5cjmcbT7mMEvuSVCRIR3nH7pcGymPl3pZaHDqW3cF55LbmuXR8j8TQK040/dM4trxO nuwm682vNAn4vaCOb8tCrRmEGGNZ/bhcXZOVZ42OxJsgpio0Ou5Q5r8IP+zEmmwMNbz7 vDYxvGkTIYdiq4+ZwhW/WdA0PWp5IRRPjOp/ol40LJRSY4Li5XfQPGyA4ZT1VDXnGsTV 2kvA== ARC-Authentication-Results: i=1; mx.google.com; dkim=pass header.i=@efficios.com header.s=smtpout1 header.b=ThHe+mc3; spf=pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 23.128.96.35 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org; dmarc=pass (p=NONE sp=NONE dis=NONE) header.from=efficios.com Received: from groat.vger.email (groat.vger.email. [23.128.96.35]) by mx.google.com with ESMTPS id w191-20020a6382c8000000b00578bb5917d7si30281180pgd.153.2023.10.02.15.50.56 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Mon, 02 Oct 2023 15:50:56 -0700 (PDT) Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 23.128.96.35 as permitted sender) client-ip=23.128.96.35; Authentication-Results: mx.google.com; dkim=pass header.i=@efficios.com header.s=smtpout1 header.b=ThHe+mc3; spf=pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 23.128.96.35 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org; dmarc=pass (p=NONE sp=NONE dis=NONE) header.from=efficios.com Received: from out1.vger.email (depot.vger.email [IPv6:2620:137:e000::3:0]) by groat.vger.email (Postfix) with ESMTP id 090F3805F5E2; Mon, 2 Oct 2023 13:26:06 -0700 (PDT) X-Virus-Status: Clean X-Virus-Scanned: clamav-milter 0.103.10 at groat.vger.email Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S235796AbjJBUZr (ORCPT + 18 others); Mon, 2 Oct 2023 16:25:47 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:50306 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229989AbjJBUZp (ORCPT ); Mon, 2 Oct 2023 16:25:45 -0400 Received: from smtpout.efficios.com (unknown [IPv6:2607:5300:203:b2ee::31e5]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 413BABF; Mon, 2 Oct 2023 13:25:41 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=efficios.com; s=smtpout1; t=1696278340; bh=59wn3SGQn5EasbWDlPH2hsibVMaavmRBQEcVCMjx328=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=ThHe+mc3wT377xFGOOGTefue/CDbHl8Kt/rUbnKtH4P8SQXiQvbA/vvBecPthNUky HMc6ucjx/uh6jMiRSJQ6Odn3w60MMxbCp6fdIRkvvhACZ7PaIvQw1JrXUF4mxy9p/5 yHw2e0ykUWyriz3kuEIf9mgqjgP592qLlyfRNjNJYCqogf64EpB6wATgLbAWNBlwzH sEyCR1I19N7YExHMi9bijPo4eFnA/4NmaHpLZsVRp+P3Uf8ShjJ/8T9zFynMulIeYe Ty3Rs2ZMettMb8Bg36Z/vF/NwNCkMjYdKZbMKMcdmpaQT0rgNuDAi1h8BX+c1nCjNw /hXeTbH1M0BzA== Received: from localhost.localdomain (192-222-143-198.qc.cable.ebox.net [192.222.143.198]) by smtpout.efficios.com (Postfix) with ESMTPSA id 4RzssJ1rbkz1V7p; Mon, 2 Oct 2023 16:25:40 -0400 (EDT) From: Mathieu Desnoyers To: Steven Rostedt Cc: linux-kernel@vger.kernel.org, Mathieu Desnoyers , Michael Jeanson , Peter Zijlstra , Alexei Starovoitov , Yonghong Song , "Paul E . McKenney" , Ingo Molnar , Arnaldo Carvalho de Melo , Mark Rutland , Alexander Shishkin , Jiri Olsa , Namhyung Kim , bpf@vger.kernel.org, Joel Fernandes Subject: [RFC PATCH v3 4/5] tracing/perf: add support for faultable tracepoints Date: Mon, 2 Oct 2023 16:25:30 -0400 Message-Id: <20231002202531.3160-5-mathieu.desnoyers@efficios.com> X-Mailer: git-send-email 2.25.1 In-Reply-To: <20231002202531.3160-1-mathieu.desnoyers@efficios.com> References: <20231002202531.3160-1-mathieu.desnoyers@efficios.com> MIME-Version: 1.0 X-Spam-Status: No, score=-0.9 required=5.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI, SPF_HELO_NONE,SPF_PASS autolearn=unavailable autolearn_force=no version=3.4.6 X-Spam-Checker-Version: SpamAssassin 3.4.6 (2021-04-09) on groat.vger.email Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org X-Greylist: Sender passed SPF test, not delayed by milter-greylist-4.6.4 (groat.vger.email [0.0.0.0]); Mon, 02 Oct 2023 13:26:06 -0700 (PDT) X-getmail-retrieved-from-mailbox: INBOX X-GMAIL-THRID: 1778685896474167183 X-GMAIL-MSGID: 1778685896474167183 In preparation for converting system call enter/exit instrumentation into faultable tracepoints, make sure that perf can handle registering to such tracepoints by explicitly disabling preemption within the perf tracepoint probes to respect the current expectations within perf ring buffer code. This change does not yet allow perf to take page faults per se within its probe, but allows its existing probes to connect to faultable tracepoints. Co-developed-by: Michael Jeanson Signed-off-by: Mathieu Desnoyers Signed-off-by: Michael Jeanson Cc: Steven Rostedt Cc: Peter Zijlstra Cc: Alexei Starovoitov Cc: Yonghong Song Cc: Paul E. McKenney Cc: Ingo Molnar Cc: Arnaldo Carvalho de Melo Cc: Mark Rutland Cc: Alexander Shishkin Cc: Jiri Olsa Cc: Namhyung Kim Cc: bpf@vger.kernel.org Cc: Joel Fernandes --- include/trace/perf.h | 27 +++++++++++++++++++++++---- 1 file changed, 23 insertions(+), 4 deletions(-) diff --git a/include/trace/perf.h b/include/trace/perf.h index 2c11181c82e0..fb47815f6eff 100644 --- a/include/trace/perf.h +++ b/include/trace/perf.h @@ -12,8 +12,8 @@ #undef __perf_task #define __perf_task(t) (__task = (t)) -#undef DECLARE_EVENT_CLASS -#define DECLARE_EVENT_CLASS(call, proto, args, tstruct, assign, print) \ +#undef _DECLARE_EVENT_CLASS +#define _DECLARE_EVENT_CLASS(call, proto, args, tstruct, assign, print, tp_flags) \ static notrace void \ perf_trace_##call(void *__data, proto) \ { \ @@ -28,13 +28,18 @@ perf_trace_##call(void *__data, proto) \ int __data_size; \ int rctx; \ \ + if ((tp_flags) & TRACEPOINT_MAY_FAULT) { \ + might_fault(); \ + preempt_disable_notrace(); \ + } \ + \ __data_size = trace_event_get_offsets_##call(&__data_offsets, args); \ \ head = this_cpu_ptr(event_call->perf_events); \ if (!bpf_prog_array_valid(event_call) && \ __builtin_constant_p(!__task) && !__task && \ hlist_empty(head)) \ - return; \ + goto end; \ \ __entry_size = ALIGN(__data_size + sizeof(*entry) + sizeof(u32),\ sizeof(u64)); \ @@ -42,7 +47,7 @@ perf_trace_##call(void *__data, proto) \ \ entry = perf_trace_buf_alloc(__entry_size, &__regs, &rctx); \ if (!entry) \ - return; \ + goto end; \ \ perf_fetch_caller_regs(__regs); \ \ @@ -53,8 +58,22 @@ perf_trace_##call(void *__data, proto) \ perf_trace_run_bpf_submit(entry, __entry_size, rctx, \ event_call, __count, __regs, \ head, __task); \ +end: \ + if ((tp_flags) & TRACEPOINT_MAY_FAULT) \ + preempt_enable_notrace(); \ } +#undef DECLARE_EVENT_CLASS +#define DECLARE_EVENT_CLASS(call, proto, args, tstruct, assign, print) \ + _DECLARE_EVENT_CLASS(call, PARAMS(proto), PARAMS(args), \ + PARAMS(tstruct), PARAMS(assign), PARAMS(print), 0) + +#undef DECLARE_EVENT_CLASS_MAY_FAULT +#define DECLARE_EVENT_CLASS_MAY_FAULT(call, proto, args, tstruct, assign, print) \ + _DECLARE_EVENT_CLASS(call, PARAMS(proto), PARAMS(args), \ + PARAMS(tstruct), PARAMS(assign), PARAMS(print), \ + TRACEPOINT_MAY_FAULT) + /* * This part is compiled out, it is only here as a build time check * to make sure that if the tracepoint handling changes, the