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 365D5C433FE for ; Wed, 23 Mar 2022 22:10:30 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1345134AbiCWWL7 (ORCPT ); Wed, 23 Mar 2022 18:11:59 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:56522 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1345119AbiCWWL5 (ORCPT ); Wed, 23 Mar 2022 18:11:57 -0400 Received: from dfw.source.kernel.org (dfw.source.kernel.org [IPv6:2604:1380:4641:c500::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 985B98EB70; Wed, 23 Mar 2022 15:10:26 -0700 (PDT) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by dfw.source.kernel.org (Postfix) with ESMTPS id 3218A61743; Wed, 23 Mar 2022 22:10:26 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id F128DC340E8; Wed, 23 Mar 2022 22:10:24 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linux-foundation.org; s=korg; t=1648073425; bh=xLoUSyyy7Fd4dqBNWHmtBAmPuHFOs/nkqaCLBf8yfFY=; h=Date:From:To:Cc:Subject:In-Reply-To:References:From; b=RaHLN8VRUw4CEvhzzrVUPpesktBspYHdxkXxAeg8BnI/U76ilSgZ7iWC5lE/qvUEL hYbW/B6Sy+sjBvRbXfnk5cbb7ENgIkeqcGHqxyaEmDtJxpRqhk4o+h64mIrKeNAa1U 6bUC1z0LIUfHkmtzDx5Et4oG817etle8+NTbhkPM= Date: Wed, 23 Mar 2022 15:10:24 -0700 From: Andrew Morton To: Luis Chamberlain Cc: Maninder Singh , pmladek@suse.com, rostedt@goodmis.org, senozhatsky@chromium.org, andriy.shevchenko@linux.intel.com, linux@rasmusvillemoes.dk, wangkefeng.wang@huawei.com, v.narang@samsung.com, swboyd@chromium.org, ojeda@kernel.org, linux-kernel@vger.kernel.org, linux-modules@vger.kernel.org, avimalin@gmail.com, atomlin@redhat.com, keescook@chromium.org, ndesaulniers@google.com, rdunlap@infradead.org, void@manifault.com Subject: Re: [PATCH 1/1 module-testing] kallsyms: enhance %pS/s/b printing when KALLSYSMS is disabled Message-Id: <20220323151024.84eb56bb87964a6e5522b1c4@linux-foundation.org> In-Reply-To: References: <20220323164742.2984281-1-maninder1.s@samsung.com> X-Mailer: Sylpheed 3.7.0 (GTK+ 2.24.33; x86_64-redhat-linux-gnu) Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, 23 Mar 2022 15:04:27 -0700 Luis Chamberlain wrote: > On Wed, Mar 23, 2022 at 10:17:42PM +0530, Maninder Singh wrote: > > --- > > module-next -> module-testing: Petr's review and test tag is picked from previous version, > > current version has slight changes (module.c -> module/main.c). No functional change in patch, > > only init_build_id() function is moved to module/main.c as it can be independent of > > kallsyms. > > Andrew, > > I see this patch is merged on your tree, any chance we can yield until > the next release and I can then take it under modules-next ? It would > help given the slew of changes I now have queued up not for v5.18 but > for v5.19. I'm delaying the modules changes for v5.19 given the timing, > it is too soon to merge for v5.18 as I want tons of testing on this > all on linux-next after v5.18-rc1 is out. > I don't actually have this patch in -mm. What I do have is the below, which I shall now drop. All yours to deal with as you see fit! From: Maninder Singh Subject: kallsyms: print module name in %ps/S case when KALLSYMS is disabled original: With KALLSYMS %pS %ps [16.4200] hello_init+0x0/0x24 [crash] hello_init [crash] Without KALLSYMS: [16.2200] 0xbe200040 0xbe200040 With Patch (Without KALLSYMS:) load address + current offset [Module Name] [13.5993] 0xbe200000+0x40 [crash] 0xbe200000+0x40 [crash] It will help in better debugging and checking when KALLSYMS is disabled, user will get information about module name and load address of module. verified for arm64: / # insmod /crash.ko [ 19.263556] 0xffff800000ec0000+0x38 [crash] .. [ 19.276023] Call trace: [ 19.276277] 0xffff800000ec0000+0x28 [crash] [ 19.276567] 0xffff800000ec0000+0x58 [crash] [ 19.276727] 0xffff800000ec0000+0x74 [crash] [ 19.276866] 0xffff8000080127d0 [ 19.276978] 0xffff80000812d95c [ 19.277085] 0xffff80000812f554 Link: https://lkml.kernel.org/r/20220201040044.1528568-1-maninder1.s@samsung.com Signed-off-by: Vaneet Narang Co-developed-by: Vaneet Narang Signed-off-by: Maninder Singh Cc: Petr Mladek Cc: Steven Rostedt (Google) Cc: Sergey Senozhatsky Cc: Andy Shevchenko Cc: Rasmus Villemoes Cc: Kefeng Wang Cc: Miroslav Benes Cc: Stephen Boyd Cc: Miguel Ojeda Cc: Will Deacon Cc: Catalin Marinas Signed-off-by: Andrew Morton --- include/linux/kallsyms.h | 27 +++++++++++++++++++++++++++ lib/vsprintf.c | 5 +++-- 2 files changed, 30 insertions(+), 2 deletions(-) --- a/include/linux/kallsyms.h~kallsyms-print-module-name-in-%ps-s-case-when-kallsyms-is-disabled +++ a/include/linux/kallsyms.h @@ -163,6 +163,33 @@ static inline bool kallsyms_show_value(c return false; } +#ifdef CONFIG_MODULES +static inline int fill_minimal_module_info(char *sym, int size, unsigned long value) +{ + struct module *mod; + unsigned long offset; + int ret = 0; + + preempt_disable(); + mod = __module_address(value); + if (mod) { + offset = value - (unsigned long)mod->core_layout.base; + snprintf(sym, size - 1, "0x%lx+0x%lx [%s]", + (unsigned long)mod->core_layout.base, offset, mod->name); + + sym[size - 1] = '\0'; + ret = 1; + } + + preempt_enable(); + return ret; +} +#else +static inline int fill_minimal_module_info(char *sym, int size, unsigned long value) +{ + return 0; +} +#endif /*CONFIG_MODULES*/ #endif /*CONFIG_KALLSYMS*/ static inline void print_ip_sym(const char *loglvl, unsigned long ip) --- a/lib/vsprintf.c~kallsyms-print-module-name-in-%ps-s-case-when-kallsyms-is-disabled +++ a/lib/vsprintf.c @@ -984,9 +984,7 @@ char *symbol_string(char *buf, char *end struct printf_spec spec, const char *fmt) { unsigned long value; -#ifdef CONFIG_KALLSYMS char sym[KSYM_SYMBOL_LEN]; -#endif if (fmt[1] == 'R') ptr = __builtin_extract_return_addr(ptr); @@ -1006,6 +1004,9 @@ char *symbol_string(char *buf, char *end return string_nocheck(buf, end, sym, spec); #else + if (fill_minimal_module_info(sym, KSYM_SYMBOL_LEN, value)) + return string_nocheck(buf, end, sym, spec); + return special_hex_number(buf, end, value, sizeof(void *)); #endif } _