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=-7.7 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_PASS,USER_AGENT_GIT 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 1784AC04EB8 for ; Tue, 4 Dec 2018 11:01:02 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id CE21B214C1 for ; Tue, 4 Dec 2018 11:01:01 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=kernel.org header.i=@kernel.org header.b="SolievR+" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org CE21B214C1 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=linuxfoundation.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 S1726817AbeLDLBA (ORCPT ); Tue, 4 Dec 2018 06:01:00 -0500 Received: from mail.kernel.org ([198.145.29.99]:46332 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727029AbeLDLA5 (ORCPT ); Tue, 4 Dec 2018 06:00:57 -0500 Received: from localhost (5356596B.cm-6-7b.dynamic.ziggo.nl [83.86.89.107]) (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 8EB4C214C1; Tue, 4 Dec 2018 11:00:56 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1543921257; bh=kiKN8juHzsOtpLvErzq1OqBEv5xMBxqSuBMzf0v/XLI=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=SolievR+Yb0kpxVZHGkcRUi2enxgIWb2uJi57mv9434KbAAZ181u3Smw8VyHaHjE5 ik9ECp09bsg3sQMJtgVdpI8XvsZ320YFL2yOHn+6JuTZy7cj6V9BtACTT45KUr6JsY prCeRr2QuI/dysikP4GuvWCGJEudJT8XmBURAfGU= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, stable@kernel.org, Masami Hiramatsu , "Steven Rostedt (VMware)" Subject: [PATCH 4.19 115/139] function_graph: Reverse the order of pushing the ret_stack and the callback Date: Tue, 4 Dec 2018 11:49:56 +0100 Message-Id: <20181204103655.349825042@linuxfoundation.org> X-Mailer: git-send-email 2.19.2 In-Reply-To: <20181204103649.950154335@linuxfoundation.org> References: <20181204103649.950154335@linuxfoundation.org> User-Agent: quilt/0.65 X-stable: review X-Patchwork-Hint: ignore MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 4.19-stable review patch. If anyone has any objections, please let me know. ------------------ From: Steven Rostedt (VMware) commit 7c6ea35ef50810aa12ab26f21cb858d980881576 upstream. The function graph profiler uses the ret_stack to store the "subtime" and reuse it by nested functions and also on the return. But the current logic has the profiler callback called before the ret_stack is updated, and it is just modifying the ret_stack that will later be allocated (it's just lucky that the "subtime" is not touched when it is allocated). This could also cause a crash if we are at the end of the ret_stack when this happens. By reversing the order of the allocating the ret_stack and then calling the callbacks attached to a function being traced, the ret_stack entry is no longer used before it is allocated. Cc: stable@kernel.org Fixes: 03274a3ffb449 ("tracing/fgraph: Adjust fgraph depth before calling trace return callback") Reviewed-by: Masami Hiramatsu Signed-off-by: Steven Rostedt (VMware) Signed-off-by: Greg Kroah-Hartman --- kernel/trace/trace_functions_graph.c | 10 ++++++---- 1 file changed, 6 insertions(+), 4 deletions(-) --- a/kernel/trace/trace_functions_graph.c +++ b/kernel/trace/trace_functions_graph.c @@ -188,15 +188,17 @@ int function_graph_enter(unsigned long r trace.func = func; trace.depth = ++current->curr_ret_depth; - /* Only trace if the calling function expects to */ - if (!ftrace_graph_entry(&trace)) - goto out; - if (ftrace_push_return_trace(ret, func, frame_pointer, retp)) goto out; + /* Only trace if the calling function expects to */ + if (!ftrace_graph_entry(&trace)) + goto out_ret; + return 0; + out_ret: + current->curr_ret_stack--; out: current->curr_ret_depth--; return -EBUSY;