Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752021AbbKAIaK (ORCPT ); Sun, 1 Nov 2015 03:30:10 -0500 Received: from mail-pa0-f51.google.com ([209.85.220.51]:36137 "EHLO mail-pa0-f51.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751047AbbKAIaI (ORCPT ); Sun, 1 Nov 2015 03:30:08 -0500 Subject: Re: [PATCH v4 6/6] arm64: ftrace: add arch-specific stack tracer Mime-Version: 1.0 (Apple Message framework v1283) Content-Type: text/plain; charset=us-ascii From: Jungseok Lee In-Reply-To: <1446182741-31019-7-git-send-email-takahiro.akashi@linaro.org> Date: Sun, 1 Nov 2015 17:30:03 +0900 Cc: catalin.marinas@arm.com, will.deacon@arm.com, rostedt@goodmis.org, olof@lixom.net, broonie@kernel.org, david.griego@linaro.org, linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org Content-Transfer-Encoding: 7bit Message-Id: <9BDC406F-52E1-4F8C-8245-7B49EC4C861D@gmail.com> References: <1446182741-31019-1-git-send-email-takahiro.akashi@linaro.org> <1446182741-31019-7-git-send-email-takahiro.akashi@linaro.org> To: AKASHI Takahiro X-Mailer: Apple Mail (2.1283) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1319 Lines: 30 On Oct 30, 2015, at 2:25 PM, AKASHI Takahiro wrote: Hi Akashi, > Stack tracer on arm64, check_stack(), is uniqeue in the following > points: > * analyze a function prologue of a traced function to estimate a more > accurate stack pointer value, replacing naive ' + 0x10.' > * use walk_stackframe(), instead of slurping stack contents as orignal > check_stack() does, to identify a stack frame and a stack index (height) > for every callsite. > > Regarding a function prologue analyzer, there is no guarantee that we can > handle all the possible patterns of function prologue as gcc does not use > any fixed templates to generate them. 'Instruction scheduling' is another > issue here. > Nevertheless, the current version will surely cover almost all the cases > in the kernel image and give us useful information on stack pointers. Can I get an idea on how to test the function prologue analyzer? It pretty tough to compare stack trace data with objdump one. Is there an easier way to observe this enhancement without objdump? Best Regards Jungseok Lee -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/