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=-5.3 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED, USER_AGENT_SANE_2 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 51192C32750 for ; Fri, 2 Aug 2019 16:11:29 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 22BD921726 for ; Fri, 2 Aug 2019 16:11:29 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2390264AbfHBQL2 (ORCPT ); Fri, 2 Aug 2019 12:11:28 -0400 Received: from mail.kernel.org ([198.145.29.99]:48184 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1732543AbfHBQL1 (ORCPT ); Fri, 2 Aug 2019 12:11:27 -0400 Received: from gandalf.local.home (cpe-66-24-58-225.stny.res.rr.com [66.24.58.225]) (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 0F61120449; Fri, 2 Aug 2019 16:11:25 +0000 (UTC) Date: Fri, 2 Aug 2019 12:11:24 -0400 From: Steven Rostedt To: Jiping Ma Cc: , , , , , Subject: Re: [PATCH v3] tracing: Function stack size and its name mismatch in arm64 Message-ID: <20190802121124.6b41f26a@gandalf.local.home> In-Reply-To: <20190802120920.3b1f4351@gandalf.local.home> References: <20190802094103.163576-1-jiping.ma2@windriver.com> <20190802112259.0530a648@gandalf.local.home> <20190802120920.3b1f4351@gandalf.local.home> X-Mailer: Claws Mail 3.17.3 (GTK+ 2.24.32; x86_64-pc-linux-gnu) MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Fri, 2 Aug 2019 12:09:20 -0400 Steven Rostedt wrote: > On Fri, 2 Aug 2019 11:22:59 -0400 > Steven Rostedt wrote: > > > I think you are not explaining the issue correctly. From looking at the > > document, I think what you want to say is that the LR is saved *after* > > the data for the function. Is that correct? If so, then yes, it would > > cause the stack tracing algorithm to be incorrect. > > > > [..] > > > Can someone confirm that this is the real issue? > > Does this patch fix your issue? > Bah, I hit "attach" instead of "insert" (I wondered why it didn't insert). Here's the patch without the attachment. -- Steve diff --git a/arch/arm64/include/asm/ftrace.h b/arch/arm64/include/asm/ftrace.h index 5ab5200b2bdc..13a4832cfb00 100644 --- a/arch/arm64/include/asm/ftrace.h +++ b/arch/arm64/include/asm/ftrace.h @@ -13,6 +13,7 @@ #define HAVE_FUNCTION_GRAPH_FP_TEST #define MCOUNT_ADDR ((unsigned long)_mcount) #define MCOUNT_INSN_SIZE AARCH64_INSN_SIZE +#define ARCH_RET_ADDR_AFTER_LOCAL_VARS 1 #ifndef __ASSEMBLY__ #include diff --git a/kernel/trace/trace_stack.c b/kernel/trace/trace_stack.c index 5d16f73898db..050c6bd9beac 100644 --- a/kernel/trace/trace_stack.c +++ b/kernel/trace/trace_stack.c @@ -158,6 +158,18 @@ static void check_stack(unsigned long ip, unsigned long *stack) i++; } +#ifdef ARCH_RET_ADDR_AFTER_LOCAL_VARS + /* + * Most archs store the return address before storing the + * function's local variables. But some archs do this backwards. + */ + if (x > 1) { + memmove(&stack_trace_index[0], &stack_trace_index[1], + sizeof(stack_trace_index[0]) * (x - 1)); + x--; + } +#endif + stack_trace_nr_entries = x; if (task_stack_end_corrupted(current)) {