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=-7.0 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE, SPF_PASS autolearn=no 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 3C19CC433DF for ; Fri, 14 Aug 2020 17:53:10 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 0B60920791 for ; Fri, 14 Aug 2020 17:53:10 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728555AbgHNRxI (ORCPT ); Fri, 14 Aug 2020 13:53:08 -0400 Received: from smtprelay0005.hostedemail.com ([216.40.44.5]:60572 "EHLO smtprelay.hostedemail.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1728488AbgHNRxH (ORCPT ); Fri, 14 Aug 2020 13:53:07 -0400 Received: from filter.hostedemail.com (clb03-v110.bra.tucows.net [216.40.38.60]) by smtprelay05.hostedemail.com (Postfix) with ESMTP id D0B8918011AD1; Fri, 14 Aug 2020 17:53:05 +0000 (UTC) X-Session-Marker: 6A6F6540706572636865732E636F6D X-HE-Tag: fact19_1e1571126ffe X-Filterd-Recvd-Size: 4135 Received: from XPS-9350.home (unknown [47.151.133.149]) (Authenticated sender: joe@perches.com) by omf18.hostedemail.com (Postfix) with ESMTPA; Fri, 14 Aug 2020 17:53:04 +0000 (UTC) Message-ID: <09f11651f0e913e159b955ac447cd8cadf36cb0d.camel@perches.com> Subject: [RFC PATCH] vsprintf: Add %pv extension replacement for print_vma_addr From: Joe Perches To: LKML Cc: Petr Mladek , Steven Rostedt , Sergey Senozhatsky , Andy Shevchenko , Rasmus Villemoes Date: Fri, 14 Aug 2020 10:53:03 -0700 Content-Type: text/plain; charset="ISO-8859-1" User-Agent: Evolution 3.36.4-0ubuntu1 MIME-Version: 1.0 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org There is a print_vma_addr function used several places that requires KERN_CONT use. Add a %pv mechanism to avoid the need for KERN_CONT. An example conversion is arch/x86/kernel/signal.c from: if (show_unhandled_signals && printk_ratelimit()) { printk("%s" "%s[%d] bad frame in %s frame:%p ip:%lx sp:%lx orax:%lx", task_pid_nr(current) > 1 ? KERN_INFO : KERN_EMERG, me->comm, me->pid, where, frame, regs->ip, regs->sp, regs->orig_ax); print_vma_addr(KERN_CONT " in ", regs->ip); pr_cont("\n"); to: printk("%s" "%s[%d] bad frame in %s frame:%p ip:%lx sp:%lx orax:%lx in %pv\n", task_pid_nr(current) > 1 ? KERN_INFO : KERN_EMERG, me->comm, me->pid, where, frame, regs->ip, regs->sp, regs->orig_ax, (void *)regs->ip); --- lib/vsprintf.c | 52 ++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 52 insertions(+) diff --git a/lib/vsprintf.c b/lib/vsprintf.c index c155769559ab..654402c43f8d 100644 --- a/lib/vsprintf.c +++ b/lib/vsprintf.c @@ -995,6 +995,12 @@ static const struct printf_spec default_dec_spec = { .precision = -1, }; +static const struct printf_spec default_hex_spec = { + .base = 16, + .precision = -1, + .flags = SMALL, +}; + static const struct printf_spec default_dec02_spec = { .base = 10, .field_width = 2, @@ -2089,6 +2095,50 @@ char *fwnode_string(char *buf, char *end, struct fwnode_handle *fwnode, return widen_string(buf, buf - buf_start, end, spec); } +static noinline_for_stack +char *vma_addr(char *buf, char *end, void *ip, + struct printf_spec spec, const char *fmt) +{ +#ifdef CONFIG_MMU + struct mm_struct *mm = current->mm; + struct vm_area_struct *vma; + + /* + * we might be running from an atomic context so we cannot sleep + */ + if (!mmap_read_trylock(mm)) + return buf; + + vma = find_vma(mm, (unsigned long)ip); + if (vma && vma->vm_file) { + char *p; + struct file *f = vma->vm_file; + char *page = (char *)__get_free_page(GFP_NOWAIT); + + if (page) { + p = file_path(f, page, PAGE_SIZE); + if (IS_ERR(p)) + p = "?"; + buf = string(buf, end, kbasename(p), default_str_spec); + buf = string_nocheck(buf, end, "[", default_str_spec); + buf = pointer_string(buf, end, + (void *)vma->vm_start, + default_hex_spec); + buf = string_nocheck(buf, end, "+", default_str_spec); + buf = pointer_string(buf, end, + (void *)(vma->vm_end - vma->vm_start), + default_hex_spec); + buf = string_nocheck(buf, end, "]", default_str_spec); + free_page((unsigned long)page); + } + } + mmap_read_unlock(mm); +#else + buf = string_nocheck(buf, end, "CONFIG_MMU=n", default_str_spec); +#endif + return buf; +} + /* * Show a '%p' thing. A kernel extension is that the '%p' is followed * by an extra set of alphanumeric characters that are extended format @@ -2254,6 +2304,8 @@ char *pointer(const char *fmt, char *buf, char *end, void *ptr, return uuid_string(buf, end, ptr, spec, fmt); case 'V': return va_format(buf, end, ptr, spec, fmt); + case 'v': + return vma_addr(buf, end, ptr, spec, fmt); case 'K': return restricted_pointer(buf, end, ptr, spec); case 'N':