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 E238BEE49A6 for ; Sun, 20 Aug 2023 14:14:13 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229899AbjHTOON (ORCPT ); Sun, 20 Aug 2023 10:14:13 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:34172 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230220AbjHTOOL (ORCPT ); Sun, 20 Aug 2023 10:14:11 -0400 Received: from dfw.source.kernel.org (dfw.source.kernel.org [139.178.84.217]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 23E444481; Sun, 20 Aug 2023 07:14:07 -0700 (PDT) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits) server-digest SHA256) (No client certificate requested) by dfw.source.kernel.org (Postfix) with ESMTPS id AD1D760F00; Sun, 20 Aug 2023 14:14:06 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id D6F2AC433C8; Sun, 20 Aug 2023 14:14:03 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1692540846; bh=JFACa1KObXJbpi3DNoml8RZIEpIaAhyTMhjq5aeWfSE=; h=Date:From:To:Cc:Subject:In-Reply-To:References:From; b=b2YbD0U5HVJCuWhCWVKB2Xpx/rnPz084FbaAEFobpqRA+IZX03T9o0ZV35DK6lPPw phzJPEfkU8W4SU5P0GLKgoqVJmt4Wg49ONYQU1Mo2A0r/q/h3Kcm3UTDMPHE+c4Pjp 5jQIOT6eY1DP7SNCaieMafPjRlQshMMrEXxT8yeKr0j/efseu4UBHKl3ZiDKvqW/DE fltfJP1L4k538Qkw2hkV6OVuH6wfmQLBI9n063NS18MKtDuCWgTF2ORAwtyTLXudwQ e+HyVSp/3dgH7I7lAnauaL0RCaAbJ3JtEUsecj4C26VfywdF5KEhty/462KuqQ89ho FY1RtXdYexbHw== Date: Sun, 20 Aug 2023 23:14:01 +0900 From: Masami Hiramatsu (Google) To: paulmck@kernel.org Cc: Alexey Dobriyan , akpm@linux-foundation.org, arnd@kernel.org, ndesaulniers@google.com, sfr@canb.auug.org.au, linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org, kernel-team@meta.com Subject: Re: [PATCH RFC bootconfig] 1/2] fs/proc: Add /proc/cmdline_load for boot loader arguments Message-Id: <20230820231401.7e6829426a3ff6baadb0b39a@kernel.org> In-Reply-To: References: <197cba95-3989-4d2f-a9f1-8b192ad08c49@paulmck-laptop> <20230728033701.817094-1-paulmck@kernel.org> <9a42de2a-7d9f-4be3-b6c8-9f3e8a092c4d@paulmck-laptop> <20230807114455.b4bab41d771556d086e8bdf4@kernel.org> <7c81c63b-7097-4d28-864e-f364eaafc5a0@paulmck-laptop> <24ec9c40-7310-4544-8c3f-81f2a756aead@paulmck-laptop> <79d0ddcf-3b20-48f5-89f6-7eb5c3fa4c88@paulmck-laptop> <20230816184003.6e0831cbe1bc7ab9a1af9a39@kernel.org> <20230817001731.35d15591bfd749c7f8fa371e@kernel.org> X-Mailer: Sylpheed 3.7.0 (GTK+ 2.24.33; x86_64-pc-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, 16 Aug 2023 09:13:30 -0700 "Paul E. McKenney" wrote: > On Thu, Aug 17, 2023 at 12:17:31AM +0900, Masami Hiramatsu wrote: > > On Wed, 16 Aug 2023 18:40:03 +0900 > > Masami Hiramatsu (Google) wrote: > > > On Mon, 14 Aug 2023 16:08:29 -0700 > > > "Paul E. McKenney" wrote: > > > > On Sat, Aug 12, 2023 at 04:30:41PM -0700, Paul E. McKenney wrote: > > > > > On Sun, Aug 06, 2023 at 09:39:28PM -0700, Paul E. McKenney wrote: > > > > > > On Mon, Aug 07, 2023 at 11:44:55AM +0900, Masami Hiramatsu wrote: > > > > > > > On Fri, 4 Aug 2023 10:36:17 -0700 > > > > > > > "Paul E. McKenney" wrote: > > > > > > > > On Fri, Aug 04, 2023 at 08:23:20PM +0300, Alexey Dobriyan wrote: > > > > > > > > > On Thu, Jul 27, 2023 at 08:37:00PM -0700, Paul E. McKenney wrote: > > > > > > > > > > In kernels built with CONFIG_BOOT_CONFIG_FORCE=y, /proc/cmdline will > > > > > > > > > > show all kernel boot parameters, both those supplied by the boot loader > > > > > > > > > > and those embedded in the kernel image. This works well for those who > > > > > > > > > > just want to see all of the kernel boot parameters, but is not helpful to > > > > > > > > > > those who need to see only those parameters supplied by the boot loader. > > > > > > > > > > This is especially important when these parameters are presented to the > > > > > > > > > > boot loader by automation that might gather them from diverse sources. > > > > > > > > > > > > > > > > > > > > Therefore, provide a /proc/cmdline_load file that shows only those kernel > > > > > > > > > > boot parameters supplied by the boot loader. > > > > > > > > > > > > > > > > > > > +static int cmdline_load_proc_show(struct seq_file *m, void *v) > > > > > > > > > > +{ > > > > > > > > > > + seq_puts(m, boot_command_line); > > > > > > > > > > + seq_putc(m, '\n'); > > > > > > > > > > + return 0; > > > > > > > > > > +} > > > > > > > > > > + > > > > > > > > > > static int __init proc_cmdline_init(void) > > > > > > > > > > { > > > > > > > > > > struct proc_dir_entry *pde; > > > > > > > > > > @@ -19,6 +27,11 @@ static int __init proc_cmdline_init(void) > > > > > > > > > > pde = proc_create_single("cmdline", 0, NULL, cmdline_proc_show); > > > > > > > > > > pde_make_permanent(pde); > > > > > > > > > > pde->size = saved_command_line_len + 1; > > > > > > > > > > + if (IS_ENABLED(CONFIG_BOOT_CONFIG_FORCE)) { > > > > > > > > > > + pde = proc_create_single("cmdline_load", 0, NULL, cmdline_load_proc_show); > > > > > > > > > > + pde_make_permanent(pde); > > > > > > > > > > + pde->size = strnlen(boot_command_line, COMMAND_LINE_SIZE) + 1; > > > > > > > > > > + } > > > > > > > > > > > > > > > > > > Please add it as separate fs/proc/cmdline_load.c file so that name of > > > > > > > > > the file matches name of the /proc file. > > > > > > > > > > > > > > > > Thank you, will do! > > > > > > > > > > > > > > > > > The name "cmdline_load" is kind of non-descriptive. Mentioning "bootloader" > > > > > > > > > somewhere should improve things. > > > > > > > > > > > > > > > > If we can all quickly come to agreement on a name, I can of course easily > > > > > > > > change it. > > > > > > > > > > > > > > > > /proc/cmdline_bootloader? Better than /proc/cmdline_from_bootloader, > > > > > > > > I suppose. /proc/cmdline_bootldr? /proc/bootloader by analogy with > > > > > > > > /proc/bootconfig? Something else? > > > > > > > > > > > > > > What about "/proc/raw_cmdline" ? > > > > > > > > > > > > That would work of me! > > > > > > > > > > > > Any objections to /proc/raw_cmdline? > > > > > > > > > > > > Going once... > > > > > > > > > > Going twice... > > > > > > > > > > If I don't hear otherwise, /proc/raw_cmdline is is on Monday August 14 PDT. > > > > > > > > And gone! > > > > > > > > Please see below for the updated version. > > > > > > OK, I'll pick this. > > > > Wait, is it OK to push this through bootconfig tree? Since this is not directly > > related to the bootconfig, fsdevel maintainer can pick this. > > I would like to ping to fsdevel people at first. > > Whichever path works best works for me! > > Here are the three commits I have queued, just please let me know when any > of them are pulled into some other tree and I will drop them from -rcu. > > 97edd1291847 ("doc: Update /proc/cmdline documentation to include boot config") > 0fe10f0d1873 ("fs/proc: Add /proc/raw_cmdline for boot loader arguments") > 9192c6ac7516 ("doc: Add /proc/bootconfig to proc.rst") OK, I picked and pushed to linux-trace's bootconfig/for-next branch. Thank you! > > Thanx, Paul > > > Thank you, > > > > > > > > Thanks! > > > > > > > > > > > Thanx, Paul > > > > > > > > ------------------------------------------------------------------------ > > > > > > > > commit 0fe10f0d1873a6f6e287c0c5b45e9203b0e33c83 > > > > Author: Paul E. McKenney > > > > Date: Fri Jul 21 16:05:38 2023 -0700 > > > > > > > > fs/proc: Add /proc/raw_cmdline for boot loader arguments > > > > > > > > In kernels built with CONFIG_BOOT_CONFIG_FORCE=y, /proc/cmdline will > > > > show all kernel boot parameters, both those supplied by the boot loader > > > > and those embedded in the kernel image. This works well for those who > > > > just want to see all of the kernel boot parameters, but is not helpful to > > > > those who need to see only those parameters supplied by the boot loader. > > > > This is especially important when these parameters are presented to the > > > > boot loader by automation that might gather them from diverse sources. > > > > It is also useful when booting the next kernel via kexec(), in which > > > > case it is necessary to supply only those kernel command-line arguments > > > > from the boot loader, and most definitely not those that were embedded > > > > into the current kernel. > > > > > > > > Therefore, provide a /proc/raw_cmdline file that shows only those kernel > > > > boot parameters supplied by the boot loader. > > > > > > > > Why put this in /proc? Because it is quite similar to /proc/cmdline, > > > > and /proc/bootconfig, so it makes sense to put it in the same place that > > > > those files are located. > > > > > > > > [ sfr: Apply kernel test robot feedback. ] > > > > [ paulmck: Apply Randy Dunlap feedback. ] > > > > [ paulmck: Apply naming feedback from Alexey Dobriyan and Masami Hiramatsu. ] > > > > > > > > Co-developed-by: Stephen Rothwell > > > > Signed-off-by: Stephen Rothwell > > > > Co-developed-by: Arnd Bergmann > > > > Signed-off-by: Arnd Bergmann > > > > Signed-off-by: Paul E. McKenney > > > > Reviewed-by: Nick Desaulniers > > > > Acked-by: Masami Hiramatsu (Google) > > > > Cc: Andrew Morton > > > > Cc: Alexey Dobriyan > > > > Cc: > > > > > > > > diff --git a/Documentation/filesystems/proc.rst b/Documentation/filesystems/proc.rst > > > > index 75a8c899ebcc..61419270c38f 100644 > > > > --- a/Documentation/filesystems/proc.rst > > > > +++ b/Documentation/filesystems/proc.rst > > > > @@ -723,6 +723,7 @@ files are there, and which are missing. > > > > partitions Table of partitions known to the system > > > > pci Deprecated info of PCI bus (new way -> /proc/bus/pci/, > > > > decoupled by lspci (2.4) > > > > + raw_cmdline Kernel command line obtained from kernel image (6.6) > > > > rtc Real time clock > > > > scsi SCSI info (see text) > > > > slabinfo Slab pool info > > > > diff --git a/fs/proc/Makefile b/fs/proc/Makefile > > > > index bd08616ed8ba..6182296f3c6b 100644 > > > > --- a/fs/proc/Makefile > > > > +++ b/fs/proc/Makefile > > > > @@ -34,3 +34,4 @@ proc-$(CONFIG_PROC_VMCORE) += vmcore.o > > > > proc-$(CONFIG_PRINTK) += kmsg.o > > > > proc-$(CONFIG_PROC_PAGE_MONITOR) += page.o > > > > proc-$(CONFIG_BOOT_CONFIG) += bootconfig.o > > > > +proc-$(CONFIG_BOOT_CONFIG_FORCE) += raw_cmdline.o > > > > diff --git a/fs/proc/raw_cmdline.c b/fs/proc/raw_cmdline.c > > > > new file mode 100644 > > > > index 000000000000..2e19eb89fc8e > > > > --- /dev/null > > > > +++ b/fs/proc/raw_cmdline.c > > > > @@ -0,0 +1,25 @@ > > > > +// SPDX-License-Identifier: GPL-2.0 > > > > +#include > > > > +#include > > > > +#include > > > > +#include > > > > +#include > > > > +#include "internal.h" > > > > + > > > > +static int raw_cmdline_proc_show(struct seq_file *m, void *v) > > > > +{ > > > > + seq_puts(m, boot_command_line); > > > > + seq_putc(m, '\n'); > > > > + return 0; > > > > +} > > > > + > > > > +static int __init proc_raw_cmdline_init(void) > > > > +{ > > > > + struct proc_dir_entry *pde; > > > > + > > > > + pde = proc_create_single("raw_cmdline", 0, NULL, raw_cmdline_proc_show); > > > > + pde_make_permanent(pde); > > > > + pde->size = strnlen(boot_command_line, COMMAND_LINE_SIZE) + 1; > > > > + return 0; > > > > +} > > > > +fs_initcall(proc_raw_cmdline_init); > > > > diff --git a/include/linux/init.h b/include/linux/init.h > > > > index 266c3e1640d4..29e75bbe7984 100644 > > > > --- a/include/linux/init.h > > > > +++ b/include/linux/init.h > > > > @@ -112,6 +112,7 @@ > > > > #define __REFCONST .section ".ref.rodata", "a" > > > > > > > > #ifndef __ASSEMBLY__ > > > > + > > > > /* > > > > * Used for initialization calls.. > > > > */ > > > > @@ -143,7 +144,7 @@ struct file_system_type; > > > > > > > > /* Defined in init/main.c */ > > > > extern int do_one_initcall(initcall_t fn); > > > > -extern char __initdata boot_command_line[]; > > > > +extern char boot_command_line[]; > > > > extern char *saved_command_line; > > > > extern unsigned int saved_command_line_len; > > > > extern unsigned int reset_devices; > > > > diff --git a/init/main.c b/init/main.c > > > > index ad920fac325c..2121685c479a 100644 > > > > --- a/init/main.c > > > > +++ b/init/main.c > > > > @@ -135,7 +135,7 @@ EXPORT_SYMBOL(system_state); > > > > void (*__initdata late_time_init)(void); > > > > > > > > /* Untouched command line saved by arch-specific code. */ > > > > -char __initdata boot_command_line[COMMAND_LINE_SIZE]; > > > > +char boot_command_line[COMMAND_LINE_SIZE] __ro_after_init; > > > > /* Untouched saved command line (eg. for /proc) */ > > > > char *saved_command_line __ro_after_init; > > > > unsigned int saved_command_line_len __ro_after_init; > > > > > > > > > -- > > > Masami Hiramatsu (Google) > > > > > > -- > > Masami Hiramatsu (Google) -- Masami Hiramatsu (Google)