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 X-Spam-Level: X-Spam-Status: No, score=-7.0 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_PASS,URIBL_BLOCKED autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 121BDC43441 for ; Thu, 22 Nov 2018 01:29:20 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id C9AD32075B for ; Thu, 22 Nov 2018 01:29:19 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org C9AD32075B Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=goodmis.org Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2391516AbeKVMGP (ORCPT ); Thu, 22 Nov 2018 07:06:15 -0500 Received: from mail.kernel.org ([198.145.29.99]:48100 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2391362AbeKVMFC (ORCPT ); Thu, 22 Nov 2018 07:05:02 -0500 Received: from gandalf.local.home (cpe-66-24-56-78.stny.res.rr.com [66.24.56.78]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 21B96208E3; Thu, 22 Nov 2018 01:28:05 +0000 (UTC) Received: from rostedt by gandalf.local.home with local (Exim 4.91) (envelope-from ) id 1gPdmm-0005Mn-2T; Wed, 21 Nov 2018 20:28:04 -0500 Message-Id: <20181122012803.976067055@goodmis.org> User-Agent: quilt/0.65 Date: Wed, 21 Nov 2018 20:27:18 -0500 From: Steven Rostedt To: linux-kernel@vger.kernel.org Cc: Ingo Molnar , Andrew Morton , Thomas Gleixner , Peter Zijlstra , Masami Hiramatsu , Josh Poimboeuf , Frederic Weisbecker , Joel Fernandes , Andy Lutomirski , Mark Rutland Subject: [RFC][PATCH 10/14] function_graph: Have profiler use new helper ftrace_graph_get_ret_stack() References: <20181122012708.491151844@goodmis.org> MIME-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-15 Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: "Steven Rostedt (VMware)" The ret_stack processing is going to change, and that is going to break anything that is accessing the ret_stack directly. One user is the function graph profiler. By using the ftrace_graph_get_ret_stack() helper function, the profiler can access the ret_stack entry without relying on the implementation details of the stack itself. Signed-off-by: Steven Rostedt (VMware) --- include/linux/ftrace.h | 3 +++ kernel/trace/fgraph.c | 11 +++++++++++ kernel/trace/ftrace.c | 21 +++++++++++---------- 3 files changed, 25 insertions(+), 10 deletions(-) diff --git a/include/linux/ftrace.h b/include/linux/ftrace.h index 5544df21a886..36a0fd1316dd 100644 --- a/include/linux/ftrace.h +++ b/include/linux/ftrace.h @@ -792,6 +792,9 @@ extern int function_graph_enter(unsigned long ret, unsigned long func, unsigned long frame_pointer, unsigned long *retp); +struct ftrace_ret_stack * +ftrace_graph_get_ret_stack(struct task_struct *task, int idx); + unsigned long ftrace_graph_ret_addr(struct task_struct *task, int *idx, unsigned long ret, unsigned long *retp); diff --git a/kernel/trace/fgraph.c b/kernel/trace/fgraph.c index c7d612897e33..9b85638ecded 100644 --- a/kernel/trace/fgraph.c +++ b/kernel/trace/fgraph.c @@ -233,6 +233,17 @@ unsigned long ftrace_return_to_handler(unsigned long frame_pointer) return ret; } +struct ftrace_ret_stack * +ftrace_graph_get_ret_stack(struct task_struct *task, int idx) +{ + idx = current->curr_ret_stack - idx; + + if (idx >= 0 && idx <= task->curr_ret_stack) + return ¤t->ret_stack[idx]; + + return NULL; +} + /** * ftrace_graph_ret_addr - convert a potentially modified stack return address * to its original value diff --git a/kernel/trace/ftrace.c b/kernel/trace/ftrace.c index d057dde081e7..05568ad4e590 100644 --- a/kernel/trace/ftrace.c +++ b/kernel/trace/ftrace.c @@ -792,7 +792,7 @@ void ftrace_graph_graph_time_control(bool enable) static int profile_graph_entry(struct ftrace_graph_ent *trace) { - int index = current->curr_ret_stack; + struct ftrace_ret_stack *ret_stack; function_profile_call(trace->func, 0, NULL, NULL); @@ -800,14 +800,16 @@ static int profile_graph_entry(struct ftrace_graph_ent *trace) if (!current->ret_stack) return 0; - if (index >= 0 && index < FTRACE_RETFUNC_DEPTH) - current->ret_stack[index].subtime = 0; + ret_stack = ftrace_graph_get_ret_stack(current, 0); + if (ret_stack) + ret_stack->subtime = 0; return 1; } static void profile_graph_return(struct ftrace_graph_ret *trace) { + struct ftrace_ret_stack *ret_stack; struct ftrace_profile_stat *stat; unsigned long long calltime; struct ftrace_profile *rec; @@ -825,16 +827,15 @@ static void profile_graph_return(struct ftrace_graph_ret *trace) calltime = trace->rettime - trace->calltime; if (!fgraph_graph_time) { - int index; - - index = current->curr_ret_stack; /* Append this call time to the parent time to subtract */ - if (index) - current->ret_stack[index - 1].subtime += calltime; + ret_stack = ftrace_graph_get_ret_stack(current, 1); + if (ret_stack) + ret_stack->subtime += calltime; - if (current->ret_stack[index].subtime < calltime) - calltime -= current->ret_stack[index].subtime; + ret_stack = ftrace_graph_get_ret_stack(current, 0); + if (ret_stack && ret_stack->subtime < calltime) + calltime -= ret_stack->subtime; else calltime = 0; } -- 2.19.1