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=-16.1 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,INCLUDES_PATCH,MAILING_LIST_MULTI, SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,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 8C65FC43465 for ; Fri, 18 Sep 2020 02:35:27 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 501DE22208 for ; Fri, 18 Sep 2020 02:35:27 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1600396527; bh=XMhfXIBtFA0Yxbw1tJScgBRrVb6G6JX3u8E/SQW3LUI=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=Vl+qcBtBHzxNCKog7zUDfhBrqccyccKu6kKHpe6uR3ZKAnDj5SrKjhPNdQU4O4a4N Ecepk1C+7+//+VDkaZGxfwkPhEW4Q4FGaPzSJ0X9Qm8ASJJXhCEru96pzF3jXFSPLI G210TQk4cPH4K8gM9GNxsus5U+6DZezmlpPPji4M= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1730020AbgIRCfO (ORCPT ); Thu, 17 Sep 2020 22:35:14 -0400 Received: from mail.kernel.org ([198.145.29.99]:40392 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727130AbgIRCNT (ORCPT ); Thu, 17 Sep 2020 22:13:19 -0400 Received: from sasha-vm.mshome.net (c-73-47-72-35.hsd1.nh.comcast.net [73.47.72.35]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 41EBB235F7; Fri, 18 Sep 2020 02:13:17 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1600395198; bh=XMhfXIBtFA0Yxbw1tJScgBRrVb6G6JX3u8E/SQW3LUI=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=XF8IZsQyHbH5Et3cMPY7aPzwf4YRm+y7uK+jqVsSstA3nbM7ylLhQNVao629JUVgE TfDd8aF7a6qZAR0cfVFt/Wi6zRc5y22lxO44oY0By3Of6c0P07yYGdZ65thWwCG+Wz BXdPMo9RsoJm2a+/TLCK8SsTilctl2nlQIifK9b4= From: Sasha Levin To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: Thomas Richter , Masami Hiramatsu , Arnaldo Carvalho de Melo , Heiko Carstens , Sumanth Korikkar , Vasily Gorbik , Sasha Levin Subject: [PATCH AUTOSEL 4.14 048/127] perf test: Fix test trace+probe_vfs_getname.sh on s390 Date: Thu, 17 Sep 2020 22:11:01 -0400 Message-Id: <20200918021220.2066485-48-sashal@kernel.org> X-Mailer: git-send-email 2.25.1 In-Reply-To: <20200918021220.2066485-1-sashal@kernel.org> References: <20200918021220.2066485-1-sashal@kernel.org> MIME-Version: 1.0 X-stable: review X-Patchwork-Hint: Ignore Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Thomas Richter [ Upstream commit 2bbc83537614517730e9f2811195004b712de207 ] This test places a kprobe to function getname_flags() in the kernel which has the following prototype: struct filename *getname_flags(const char __user *filename, int flags, int *empty) The 'filename' argument points to a filename located in user space memory. Looking at commit 88903c464321c ("tracing/probe: Add ustring type for user-space string") the kprobe should indicate that user space memory is accessed. Output before: [root@m35lp76 perf]# ./perf test 66 67 66: Use vfs_getname probe to get syscall args filenames : FAILED! 67: Check open filename arg using perf trace + vfs_getname: FAILED! [root@m35lp76 perf]# Output after: [root@m35lp76 perf]# ./perf test 66 67 66: Use vfs_getname probe to get syscall args filenames : Ok 67: Check open filename arg using perf trace + vfs_getname: Ok [root@m35lp76 perf]# Comments from Masami Hiramatsu: This bug doesn't happen on x86 or other archs on which user address space and kernel address space is the same. On some arches (ppc64 in this case?) user address space is partially or completely the same as kernel address space. (Yes, they switch the world when running into the kernel) In this case, we need to use different data access functions for each space. That is why I introduced the "ustring" type for kprobe events. As far as I can see, Thomas's patch is sane. Thomas, could you show us your result on your test environment? Comments from Thomas Richter: Test results for s/390 included above. Signed-off-by: Thomas Richter Acked-by: Masami Hiramatsu Tested-by: Arnaldo Carvalho de Melo Cc: Heiko Carstens Cc: Sumanth Korikkar Cc: Vasily Gorbik Link: http://lore.kernel.org/lkml/20200217102111.61137-1-tmricht@linux.ibm.com Signed-off-by: Arnaldo Carvalho de Melo Signed-off-by: Sasha Levin --- tools/perf/tests/shell/lib/probe_vfs_getname.sh | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/tools/perf/tests/shell/lib/probe_vfs_getname.sh b/tools/perf/tests/shell/lib/probe_vfs_getname.sh index 068d463e5cbfc..4b0922a209701 100644 --- a/tools/perf/tests/shell/lib/probe_vfs_getname.sh +++ b/tools/perf/tests/shell/lib/probe_vfs_getname.sh @@ -14,7 +14,7 @@ add_probe_vfs_getname() { if [ $had_vfs_getname -eq 1 ] ; then line=$(perf probe -L getname_flags 2>&1 | egrep 'result.*=.*filename;' | sed -r 's/[[:space:]]+([[:digit:]]+)[[:space:]]+result->uptr.*/\1/') perf probe -q "vfs_getname=getname_flags:${line} pathname=result->name:string" || \ - perf probe $verbose "vfs_getname=getname_flags:${line} pathname=filename:string" + perf probe $verbose "vfs_getname=getname_flags:${line} pathname=filename:ustring" fi } -- 2.25.1