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=-8.8 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE, SPF_PASS 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 1EC9CC433E0 for ; Sat, 6 Feb 2021 17:57:49 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id CA5EB64E2F for ; Sat, 6 Feb 2021 17:57:48 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230366AbhBFR5s (ORCPT ); Sat, 6 Feb 2021 12:57:48 -0500 Received: from smtprelay0010.hostedemail.com ([216.40.44.10]:47152 "EHLO smtprelay.hostedemail.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S230251AbhBFR5r (ORCPT ); Sat, 6 Feb 2021 12:57:47 -0500 Received: from filter.hostedemail.com (clb03-v110.bra.tucows.net [216.40.38.60]) by smtprelay03.hostedemail.com (Postfix) with ESMTP id 225168384365; Sat, 6 Feb 2021 17:57:04 +0000 (UTC) X-Session-Marker: 6A6F6540706572636865732E636F6D X-HE-Tag: power55_5f041ec275ef X-Filterd-Recvd-Size: 3908 Received: from [192.168.1.159] (unknown [47.151.137.21]) (Authenticated sender: joe@perches.com) by omf11.hostedemail.com (Postfix) with ESMTPA; Sat, 6 Feb 2021 17:57:01 +0000 (UTC) Message-ID: <49124db60cdc88c4e9fcca1bbc9767432ad5a93b.camel@perches.com> Subject: Re: [PATCH] printk: Userspace format enumeration support From: Joe Perches To: Chris Down , Petr Mladek Cc: linux-kernel@vger.kernel.org, Sergey Senozhatsky , John Ogness , Johannes Weiner , Andrew Morton , kernel-team@fb.com, Steven Rostedt , Alexey Dobriyan , Greg Kroah-Hartman , Jason Baron , Kees Cook , linux-api@vger.kernel.org Date: Sat, 06 Feb 2021 09:57:00 -0800 In-Reply-To: References: Content-Type: text/plain; charset="ISO-8859-1" User-Agent: Evolution 3.38.1-1 MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-api@vger.kernel.org On Fri, 2021-02-05 at 22:25 +0000, Chris Down wrote: > Petr Mladek writes: > >   + is already optinaly added by pr_fmt() to the printed strings > >     as: pr_fmt(): ... > > pr_fmts are not consistently used across the kernel, and sometimes differ from > the module itself. Many modules don't use it at all, and we also don't have it > for pr_cont. Just picking some random examples: > >      % grep -av vmlinux /proc/printk_formats | shuf -n 10 >      mac80211,6%s: mesh STA %pM switches to channel requiring DFS (%d MHz, width:%d, CF1/2: %d/%d MHz), aborting >      thinkpad_acpi,c N/Athinkpad_acpi,c %dthinkpad_acpi,5thinkpad_acpi: temperatures (Celsius):thinkpad_acpi,3thinkpad_acpi: Out of memory for LED data I don't understand this format. "Out of memory for LED data" is a single printk ending with a '\n' newline I expected this to be broken up into multiple lines, one for each printk that endsd in a newline. And what would happen if the function was refactored removing the pr_cont uses like the below: (basically, any output that uses a mechanism that aggregates a buffer then emits it, and there are a _lot_ of those) printk("%s\n", buffer); And there is already a relatively trivial way to do this using a modified version of strings that looks for KERN_SOH[0-6], and if dynamic_debug is enabled, look in the dynamic_debug section, either __verbose or __dyndbg depending on the kernel version. --- drivers/platform/x86/thinkpad_acpi.c | 15 ++++++++++----- 1 file changed, 10 insertions(+), 5 deletions(-) diff --git a/drivers/platform/x86/thinkpad_acpi.c b/drivers/platform/x86/thinkpad_acpi.c index 18b390153e7f..ff1c09c600f8 100644 --- a/drivers/platform/x86/thinkpad_acpi.c +++ b/drivers/platform/x86/thinkpad_acpi.c @@ -6353,21 +6353,26 @@ static void thermal_dump_all_sensors(void) { int n, i; struct ibm_thermal_sensors_struct t; + char output[256]; + int len = 0; n = thermal_get_sensors(&t); if (n <= 0) return; - pr_notice("temperatures (Celsius):"); + len += scnprintf(output + len, sizeof(output) - len, + "temperatures (Celsius):"); for (i = 0; i < n; i++) { - if (t.temp[i] != TPACPI_THERMAL_SENSOR_NA) - pr_cont(" %d", (int)(t.temp[i] / 1000)); + if (t.temp[i] == TPACPI_THERMAL_SENSOR_NA) + len += scnprintf(output + len, sizeof(output) - len, + " N/A"); else - pr_cont(" N/A"); + len += scnprintf(output + len, sizeof(output) - len, + " %d", t.temp[i] / 1000); } - pr_cont("\n"); + pr_notice("%s\n", output); } /* sysfs temp##_input -------------------------------------------------- */