From patchwork Mon Dec 18 13:14:35 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: "Masami Hiramatsu (Google)" X-Patchwork-Id: 180401 Return-Path: Delivered-To: ouuuleilei@gmail.com Received: by 2002:a05:7300:24d3:b0:fb:cd0c:d3e with SMTP id r19csp1235688dyi; Mon, 18 Dec 2023 05:24:23 -0800 (PST) X-Google-Smtp-Source: AGHT+IHm81tWen9NNu2V7N/aqbLSto0OEvzXPHwA6Fjzh3K9itX+LNkPjhiVnUut2uwTkIVnSpbD X-Received: by 2002:a05:6e02:1a46:b0:35d:5995:903b with SMTP id u6-20020a056e021a4600b0035d5995903bmr16009080ilv.46.1702905863230; Mon, 18 Dec 2023 05:24:23 -0800 (PST) ARC-Seal: i=1; a=rsa-sha256; t=1702905863; cv=none; d=google.com; s=arc-20160816; b=O4qFrJDtieyvtQmw3NBIWEDmc+9Jv10s9UKwFpQaF5qqQBj0kooXXEKVXURGhNJpmf u9vT+SZc+bBYhUnlmbpqYF9ptCmFNLH/8gwemVrfMnlUrFu0ABHXXXP3ixEEIM+ep+5C 7Kiy9GFiWa9KxaPHMyV3IDC7iJJDPRK/EACtTMg+qLSBNcH/LXNNwY/QYr7RJ8boYbUu Kmyie+WreydfFWAVce/OY/0nRH5Ew2W/cRqHL2j2ZHt7C5k9fw1mHS/JeyjEVOW6kzct 1+IkWQ8D+JFx3HoKKs2D0Ltwtmk01LvpXTPNeNr31lxzImZ2tioPuLj75EGKxPgG4uQB duHw== ARC-Message-Signature: i=1; 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:user-agent:references:in-reply-to :message-id:date:subject:cc:to:from:dkim-signature; bh=Oq9Fo56RGVbai0FVad+d2OOgEML+m+c+a5p19CzL7Jg=; fh=SIgps5XdV0XNwjZfT2uAI7g3mrspDldK9Qs8qQAfoa4=; b=OyCyTTW1sli1K9/v2SN3Ife0l/Tigs4364bzSVjnkuDNqVBC62Ogh/B9XR34IJBL01 1zZrsKD1dC7xN1+B6gn0jFg6o5yFQRLHhxFB54n7ZMPqFvX5/GOd3ZX8CG2FQ84FPiq2 KHWI9+NWKJfaa5uiHkz04/g+zc7NPF78p3teTRNz/KvPz32qa9UW/7ZAX+8IrP2F3wsm 4fFUSm88V/rczlN2ote9V4sRo/UqyziR3Vmhn1IVUNU5lwi+jNOzmA1Pv/nIRw4+Clgv 0wL09qn+kyztCuYs1555dOrcKi+Tzf9rv15ez6CCHSdxUsMiI8rM+XADbq8X0fpmEA2S o7PQ== ARC-Authentication-Results: i=1; mx.google.com; dkim=pass header.i=@kernel.org header.s=k20201202 header.b=B4sPEvqA; spf=pass (google.com: domain of linux-kernel+bounces-3719-ouuuleilei=gmail.com@vger.kernel.org designates 2604:1380:45e3:2400::1 as permitted sender) smtp.mailfrom="linux-kernel+bounces-3719-ouuuleilei=gmail.com@vger.kernel.org"; dmarc=pass (p=NONE sp=NONE dis=NONE) header.from=kernel.org Received: from sv.mirrors.kernel.org (sv.mirrors.kernel.org. [2604:1380:45e3:2400::1]) by mx.google.com with ESMTPS id u3-20020a631403000000b005b21d089aa7si17950355pgl.788.2023.12.18.05.24.23 for (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Mon, 18 Dec 2023 05:24:23 -0800 (PST) Received-SPF: pass (google.com: domain of linux-kernel+bounces-3719-ouuuleilei=gmail.com@vger.kernel.org designates 2604:1380:45e3:2400::1 as permitted sender) client-ip=2604:1380:45e3:2400::1; Authentication-Results: mx.google.com; dkim=pass header.i=@kernel.org header.s=k20201202 header.b=B4sPEvqA; spf=pass (google.com: domain of linux-kernel+bounces-3719-ouuuleilei=gmail.com@vger.kernel.org designates 2604:1380:45e3:2400::1 as permitted sender) smtp.mailfrom="linux-kernel+bounces-3719-ouuuleilei=gmail.com@vger.kernel.org"; dmarc=pass (p=NONE sp=NONE dis=NONE) header.from=kernel.org 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 F0B8D2865F4 for ; Mon, 18 Dec 2023 13:20:06 +0000 (UTC) Received: from localhost.localdomain (localhost.localdomain [127.0.0.1]) by smtp.subspace.kernel.org (Postfix) with ESMTP id 9EEAB71465; Mon, 18 Dec 2023 13:14:45 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="B4sPEvqA" X-Original-To: linux-kernel@vger.kernel.org Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id C9DF33788B; Mon, 18 Dec 2023 13:14:42 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 32BFFC433C7; Mon, 18 Dec 2023 13:14:39 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1702905282; bh=4gnOPh72MBp2/UPzOPml+kmyjzVijWhiPGlAlFNB6DE=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=B4sPEvqAuTYIQkOb5zeeKz5+SdlFP15zfP7e/bSZdETJFyOgtBWZukSgtySAU5GNU jiKbvVZ78ayP158hhw54aIxUqZRkdyRz30BZ1gdeT7Gcu8cVO9hLlFtrW8DER6cmjD VvmpsUyihPLDLWDRIAqoNFq7YiiMmebWxd3OYOAFSVCxqRPkveM308ftCi7VbwizWy 3pbB9x6hkMBXjBj5PwU2Kpm4sFxnRXKTmZn4YV9CWQ5O0W2NTSobehlMR+QlR89vMy PGCLHLhzFxuzP0xwRgbageCW8L1ac1o+7/TPn7wenGignM+8WLQ9mx0xOzXl4R+gKO V2XSJuX9iu89g== From: "Masami Hiramatsu (Google)" To: Alexei Starovoitov , Steven Rostedt , Florent Revest Cc: linux-trace-kernel@vger.kernel.org, LKML , Martin KaFai Lau , bpf , Sven Schnelle , Alexei Starovoitov , Jiri Olsa , Arnaldo Carvalho de Melo , Daniel Borkmann , Alan Maguire , Mark Rutland , Peter Zijlstra , Thomas Gleixner , Guo Ren Subject: [PATCH v5 15/34] function_graph: Move graph depth stored data to shadow stack global var Date: Mon, 18 Dec 2023 22:14:35 +0900 Message-Id: <170290527470.220107.16894083688641098524.stgit@devnote2> X-Mailer: git-send-email 2.34.1 In-Reply-To: <170290509018.220107.1347127510564358608.stgit@devnote2> References: <170290509018.220107.1347127510564358608.stgit@devnote2> User-Agent: StGit/0.19 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: 1785626218852490827 X-GMAIL-MSGID: 1785626218852490827 From: Steven Rostedt (VMware) The use of the task->trace_recursion for the logic used for the function graph depth was a bit of an abuse of that variable. Now that there exists global vars that are per stack for registered graph traces, use that instead. Signed-off-by: Steven Rostedt (VMware) Signed-off-by: Masami Hiramatsu (Google) --- include/linux/trace_recursion.h | 29 ----------------------------- kernel/trace/trace.h | 34 ++++++++++++++++++++++++++++++++-- 2 files changed, 32 insertions(+), 31 deletions(-) diff --git a/include/linux/trace_recursion.h b/include/linux/trace_recursion.h index 2efd5ec46d7f..00e792bf148d 100644 --- a/include/linux/trace_recursion.h +++ b/include/linux/trace_recursion.h @@ -44,25 +44,6 @@ enum { */ TRACE_IRQ_BIT, - /* - * In the very unlikely case that an interrupt came in - * at a start of graph tracing, and we want to trace - * the function in that interrupt, the depth can be greater - * than zero, because of the preempted start of a previous - * trace. In an even more unlikely case, depth could be 2 - * if a softirq interrupted the start of graph tracing, - * followed by an interrupt preempting a start of graph - * tracing in the softirq, and depth can even be 3 - * if an NMI came in at the start of an interrupt function - * that preempted a softirq start of a function that - * preempted normal context!!!! Luckily, it can't be - * greater than 3, so the next two bits are a mask - * of what the depth is when we set TRACE_GRAPH_FL - */ - - TRACE_GRAPH_DEPTH_START_BIT, - TRACE_GRAPH_DEPTH_END_BIT, - /* * To implement set_graph_notrace, if this bit is set, we ignore * function graph tracing of called functions, until the return @@ -78,16 +59,6 @@ enum { #define trace_recursion_clear(bit) do { (current)->trace_recursion &= ~(1<<(bit)); } while (0) #define trace_recursion_test(bit) ((current)->trace_recursion & (1<<(bit))) -#define trace_recursion_depth() \ - (((current)->trace_recursion >> TRACE_GRAPH_DEPTH_START_BIT) & 3) -#define trace_recursion_set_depth(depth) \ - do { \ - current->trace_recursion &= \ - ~(3 << TRACE_GRAPH_DEPTH_START_BIT); \ - current->trace_recursion |= \ - ((depth) & 3) << TRACE_GRAPH_DEPTH_START_BIT; \ - } while (0) - #define TRACE_CONTEXT_BITS 4 #define TRACE_FTRACE_START TRACE_FTRACE_BIT diff --git a/kernel/trace/trace.h b/kernel/trace/trace.h index 3b9266aeb43b..e3f452eda0e3 100644 --- a/kernel/trace/trace.h +++ b/kernel/trace/trace.h @@ -896,8 +896,38 @@ extern void free_fgraph_ops(struct trace_array *tr); enum { TRACE_GRAPH_FL = 1, + + /* + * In the very unlikely case that an interrupt came in + * at a start of graph tracing, and we want to trace + * the function in that interrupt, the depth can be greater + * than zero, because of the preempted start of a previous + * trace. In an even more unlikely case, depth could be 2 + * if a softirq interrupted the start of graph tracing, + * followed by an interrupt preempting a start of graph + * tracing in the softirq, and depth can even be 3 + * if an NMI came in at the start of an interrupt function + * that preempted a softirq start of a function that + * preempted normal context!!!! Luckily, it can't be + * greater than 3, so the next two bits are a mask + * of what the depth is when we set TRACE_GRAPH_FL + */ + + TRACE_GRAPH_DEPTH_START_BIT, + TRACE_GRAPH_DEPTH_END_BIT, }; +static inline unsigned long ftrace_graph_depth(unsigned long *task_var) +{ + return (*task_var >> TRACE_GRAPH_DEPTH_START_BIT) & 3; +} + +static inline void ftrace_graph_set_depth(unsigned long *task_var, int depth) +{ + *task_var &= ~(3 << TRACE_GRAPH_DEPTH_START_BIT); + *task_var |= (depth & 3) << TRACE_GRAPH_DEPTH_START_BIT; +} + #ifdef CONFIG_DYNAMIC_FTRACE extern struct ftrace_hash __rcu *ftrace_graph_hash; extern struct ftrace_hash __rcu *ftrace_graph_notrace_hash; @@ -930,7 +960,7 @@ ftrace_graph_addr(unsigned long *task_var, struct ftrace_graph_ent *trace) * when the depth is zero. */ *task_var |= TRACE_GRAPH_FL; - trace_recursion_set_depth(trace->depth); + ftrace_graph_set_depth(task_var, trace->depth); /* * If no irqs are to be traced, but a set_graph_function @@ -955,7 +985,7 @@ ftrace_graph_addr_finish(struct fgraph_ops *gops, struct ftrace_graph_ret *trace unsigned long *task_var = fgraph_get_task_var(gops); if ((*task_var & TRACE_GRAPH_FL) && - trace->depth == trace_recursion_depth()) + trace->depth == ftrace_graph_depth(task_var)) *task_var &= ~TRACE_GRAPH_FL; }