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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 5FA47C25B04 for ; Thu, 15 Dec 2022 09:16:38 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229868AbiLOJQh (ORCPT ); Thu, 15 Dec 2022 04:16:37 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:55816 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229884AbiLOJQ3 (ORCPT ); Thu, 15 Dec 2022 04:16:29 -0500 Received: from szxga02-in.huawei.com (szxga02-in.huawei.com [45.249.212.188]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id F2B384B9A1; Thu, 15 Dec 2022 01:16:23 -0800 (PST) Received: from dggpemm500006.china.huawei.com (unknown [172.30.72.56]) by szxga02-in.huawei.com (SkyGuard) with ESMTP id 4NXmmG4CqfzJqXt; Thu, 15 Dec 2022 17:15:26 +0800 (CST) Received: from [10.174.178.55] (10.174.178.55) by dggpemm500006.china.huawei.com (7.185.36.236) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2375.34; Thu, 15 Dec 2022 17:16:20 +0800 Subject: Re: [PATCH v9] kallsyms: Add self-test facility To: Geert Uytterhoeven CC: Josh Poimboeuf , Jiri Kosina , Miroslav Benes , Petr Mladek , Joe Lawrence , , , Masahiro Yamada , Alexei Starovoitov , Jiri Olsa , Kees Cook , Andrew Morton , Luis Chamberlain , , Steven Rostedt , Ingo Molnar , David Laight , linux-m68k References: <20221115083349.1662-1-thunder.leizhen@huawei.com> From: "Leizhen (ThunderTown)" Message-ID: Date: Thu, 15 Dec 2022 17:16:09 +0800 User-Agent: Mozilla/5.0 (Windows NT 10.0; WOW64; rv:60.0) Gecko/20100101 Thunderbird/60.7.0 MIME-Version: 1.0 In-Reply-To: Content-Type: text/plain; charset="utf-8" Content-Language: en-US Content-Transfer-Encoding: 7bit X-Originating-IP: [10.174.178.55] X-ClientProxiedBy: dggems706-chm.china.huawei.com (10.3.19.183) To dggpemm500006.china.huawei.com (7.185.36.236) X-CFilter-Loop: Reflected Precedence: bulk List-ID: On 2022/12/15 16:50, Geert Uytterhoeven wrote: > Hi Zhen, > > On Tue, Nov 15, 2022 at 9:41 AM Zhen Lei wrote: >> Added test cases for basic functions and performance of functions >> kallsyms_lookup_name(), kallsyms_on_each_symbol() and >> kallsyms_on_each_match_symbol(). It also calculates the compression rate >> of the kallsyms compression algorithm for the current symbol set. >> >> The basic functions test begins by testing a set of symbols whose address >> values are known. Then, traverse all symbol addresses and find the >> corresponding symbol name based on the address. It's impossible to >> determine whether these addresses are correct, but we can use the above >> three functions along with the addresses to test each other. Due to the >> traversal operation of kallsyms_on_each_symbol() is too slow, only 60 >> symbols can be tested in one second, so let it test on average once >> every 128 symbols. The other two functions validate all symbols. >> >> If the basic functions test is passed, print only performance test >> results. If the test fails, print error information, but do not perform >> subsequent performance tests. >> >> Start self-test automatically after system startup if >> CONFIG_KALLSYMS_SELFTEST=y. >> >> Example of output content: (prefix 'kallsyms_selftest:' is omitted >> start >> --------------------------------------------------------- >> | nr_symbols | compressed size | original size | ratio(%) | >> |---------------------------------------------------------| >> | 107543 | 1357912 | 2407433 | 56.40 | >> --------------------------------------------------------- >> kallsyms_lookup_name() looked up 107543 symbols >> The time spent on each symbol is (ns): min=630, max=35295, avg=7353 >> kallsyms_on_each_symbol() traverse all: 11782628 ns >> kallsyms_on_each_match_symbol() traverse all: 9261 ns >> finish >> >> Signed-off-by: Zhen Lei > > Thanks for your patch, which is now commit 30f3bb09778de64e ("kallsyms: > Add self-test facility") in linus/master. > > I gave this a try on m68k (atari_defconfig + CONFIG_KALLSYMS_SELFTEST=y), > but it failed: > > start > kallsyms_lookup_name() for kallsyms_test_func_static failed: > addr=0, expect 60ab0 > kallsyms_lookup_name() for kallsyms_test_func failed: addr=0, expect 60ac0 > kallsyms_lookup_name() for kallsyms_test_func_weak failed: addr=0, > expect 60ac2 > kallsyms_lookup_name() for vmalloc failed: addr=0, expect c272a > kallsyms_lookup_name() for vfree failed: addr=0, expect c2142 > kallsyms_on_each_match_symbol() for kallsyms_test_func_static > failed: count=0, addr=0, expect 60ab0 > kallsyms_on_each_match_symbol() for kallsyms_test_func failed: > count=0, addr=0, expect 60ac0 > kallsyms_on_each_match_symbol() for kallsyms_test_func_weak > failed: count=0, addr=0, expect 60ac2 > kallsyms_on_each_match_symbol() for vmalloc failed: count=0, > addr=0, expect c272a > kallsyms_on_each_match_symbol() for vfree failed: count=0, addr=0, > expect c2142 > abort > > Given all addresses are zero, it looks like some required functionality > or config option is missing. > > $ grep SYM .config > CONFIG_KALLSYMS=y > CONFIG_KALLSYMS_SELFTEST=y > CONFIG_KALLSYMS_BASE_RELATIVE=y > # CONFIG_ASYMMETRIC_KEY_TYPE is not set > CONFIG_SYMBOLIC_ERRNAME=y > # CONFIG_STRIP_ASM_SYMS is not set > CONFIG_KALLSYMS_SELFTEST > > Do you have a clue? cat /proc/kallsyms | grep kallsyms_test_func Let's see if the compiler-generated symbols have some special suffixes. > > Gr{oetje,eeting}s, > > Geert > > -- > Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@linux-m68k.org > > In personal conversations with technical people, I call myself a hacker. But > when I'm talking to journalists I just say "programmer" or something like that. > -- Linus Torvalds > > . > -- Regards, Zhen Lei