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=DKIM_SIGNED,DKIM_VALID, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_PASS,URIBL_BLOCKED autolearn=unavailable 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 A60E1C04AAA for ; Sun, 5 May 2019 01:51:12 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 6423C20700 for ; Sun, 5 May 2019 01:51:12 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=nifty.com header.i=@nifty.com header.b="jVKKTnN7" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727344AbfEEBvI (ORCPT ); Sat, 4 May 2019 21:51:08 -0400 Received: from conssluserg-02.nifty.com ([210.131.2.81]:43600 "EHLO conssluserg-02.nifty.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726390AbfEEBvI (ORCPT ); Sat, 4 May 2019 21:51:08 -0400 Received: from mail-ua1-f41.google.com (mail-ua1-f41.google.com [209.85.222.41]) (authenticated) by conssluserg-02.nifty.com with ESMTP id x451odLI015095; Sun, 5 May 2019 10:50:39 +0900 DKIM-Filter: OpenDKIM Filter v2.10.3 conssluserg-02.nifty.com x451odLI015095 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=nifty.com; s=dec2015msa; t=1557021040; bh=HxqhNXUccAGwVFV55EiI+BIgzu6GPW9Pcu4RFLUIwGU=; h=References:In-Reply-To:From:Date:Subject:To:Cc:From; b=jVKKTnN7gGX/4LSR3iRCFynUZdWVlCDnHoTLXzAMIIAih28B7Dk4CYmbP1QjZNjwK FlZA+eGMERiBUNMpJIadPgl78bHf3XZFHAzM6+EDEZGlk2kJ+g0XGE00kLszfPch3O qe2PwWhG7tf6MGfKGRf3hBJTG9nvqQidLwCpB/YhgYQd71k0366+OpztwVoM2mmIIh l2vT55WKslfF2TvAWTbFnQEe6M4pGfwYKOUWlcRcS6CDfcDMpPrfrl+W4aluo5pi2J K4hhvjcXil40UG0fThPCXIF/qu9adtILlOHALWjbWjirGnYmiSZseBt51DOKcvRDeN vGnA0LBBJQ3AQ== X-Nifty-SrcIP: [209.85.222.41] Received: by mail-ua1-f41.google.com with SMTP id n23so3409518uap.13; Sat, 04 May 2019 18:50:39 -0700 (PDT) X-Gm-Message-State: APjAAAWrbyAobuHjl7nfNgbgLM6rOD76Sv2vOO372wb4zDjKQ6AnU7ww 0Vwehnsu6oDqw/ptwkPGLpV7iqFCYWBSqDro+jQ= X-Google-Smtp-Source: APXvYqyto4ywW4Iezc4YOr2mUelBO4Me/wMnxNfrtcwB3XD3vHe4ZMaidSA58I9jVgOGsG83g8VowvGi+NCqMERjTtU= X-Received: by 2002:ab0:2bd8:: with SMTP id s24mr9344582uar.121.1557021038230; Sat, 04 May 2019 18:50:38 -0700 (PDT) MIME-Version: 1.0 References: <20190504121213.183203-1-joel@joelfernandes.org> In-Reply-To: <20190504121213.183203-1-joel@joelfernandes.org> From: Masahiro Yamada Date: Sun, 5 May 2019 10:50:02 +0900 X-Gmail-Original-Message-ID: Message-ID: Subject: Re: [PATCH v2] kheaders: Move from proc to sysfs To: "Joel Fernandes (Google)" Cc: Linux Kernel Mailing List , Steven Rostedt , Adrian Ratiu , Alexei Starovoitov , Andrew Morton , atish patra , bpf@vger.kernel.org, Brendan Gregg , Brendan Gregg , Daniel Colascione , Daniel Borkmann , Dan Williams , Dietmar Eggemann , duyuchao , Greg Kroah-Hartman , Guenter Roeck , Jonathan Corbet , Karim Yaghmour , Kees Cook , "Cc: Android Kernel" , "open list:DOCUMENTATION" , "open list:KERNEL SELFTEST FRAMEWORK" , linux-trace-devel@vger.kernel.org, Manjo Raja Rao , Masami Hiramatsu , =?UTF-8?Q?Micha=C5=82_Gregorczyk?= , Michal Gregorczyk , Mohammad Husain , Olof Johansson , Qais Yousef , Randy Dunlap , Shuah Khan , Srinivas Ramana , Tamir Carmeli , Yonghong Song Content-Type: text/plain; charset="UTF-8" Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Sat, May 4, 2019 at 9:26 PM Joel Fernandes (Google) wrote: > > The kheaders archive consisting of the kernel headers used for compiling > bpf programs is in /proc. However there is concern that moving it here > will make it permanent. Let us move it to /sys/kernel as discussed [1]. > > [1] https://lore.kernel.org/patchwork/patch/1067310/#1265969 > > Suggested-by: Steven Rostedt > Signed-off-by: Joel Fernandes (Google) > --- > This patch applies on top of the previous patch that was applied to the > driver tree: > https://lore.kernel.org/patchwork/patch/1067310/ > > v1->v2: Fixed some kconfig nits (Masami). My name is Masahiro, just in case. > > init/Kconfig | 16 ++++----- > kernel/Makefile | 4 +-- > kernel/{gen_ikh_data.sh => gen_kheaders.sh} | 2 +- > kernel/kheaders.c | 40 +++++++++------------ > 4 files changed, 26 insertions(+), 36 deletions(-) > rename kernel/{gen_ikh_data.sh => gen_kheaders.sh} (98%) > > diff --git a/init/Kconfig b/init/Kconfig > index 26a364a95b57..c3661991b089 100644 > --- a/init/Kconfig > +++ b/init/Kconfig > @@ -579,15 +579,13 @@ config IKCONFIG_PROC > This option enables access to the kernel configuration file > through /proc/config.gz. > > -config IKHEADERS_PROC > - tristate "Enable kernel header artifacts through /proc/kheaders.tar.xz" > - depends on PROC_FS > - help > - This option enables access to the kernel header and other artifacts that > - are generated during the build process. These can be used to build eBPF > - tracing programs, or similar programs. If you build the headers as a > - module, a module called kheaders.ko is built which can be loaded on-demand > - to get access to the headers. > +config IKHEADERS > + tristate "Enable kernel headers through /sys/kernel/kheaders.tar.xz" In v1, I suggested to change "depends on PROC_FS" to "depends on SYSFS". fs/sysfs/ must be compiled to make this feature work. > + help > + This option enables access to the in-kernel headers that are generated during > + the build process. These can be used to build eBPF tracing programs, > + or similar programs. If you build the headers as a module, a module called While you are touching the help, could you make the number of spaces between sentences consistent? Thanks. > + kheaders.ko is built which can be loaded on-demand to get access to headers. > > config LOG_BUF_SHIFT > int "Kernel log buffer size (16 => 64KB, 17 => 128KB)" > diff --git a/kernel/Makefile b/kernel/Makefile > index 12399614c350..b32a558fae2f 100644 > --- a/kernel/Makefile > +++ b/kernel/Makefile > @@ -70,7 +70,7 @@ obj-$(CONFIG_UTS_NS) += utsname.o > obj-$(CONFIG_USER_NS) += user_namespace.o > obj-$(CONFIG_PID_NS) += pid_namespace.o > obj-$(CONFIG_IKCONFIG) += configs.o > -obj-$(CONFIG_IKHEADERS_PROC) += kheaders.o > +obj-$(CONFIG_IKHEADERS) += kheaders.o > obj-$(CONFIG_SMP) += stop_machine.o > obj-$(CONFIG_KPROBES_SANITY_TEST) += test_kprobes.o > obj-$(CONFIG_AUDIT) += audit.o auditfilter.o > @@ -126,7 +126,7 @@ $(obj)/config_data.gz: $(KCONFIG_CONFIG) FORCE > $(obj)/kheaders.o: $(obj)/kheaders_data.tar.xz > > quiet_cmd_genikh = CHK $(obj)/kheaders_data.tar.xz > -cmd_genikh = $(srctree)/kernel/gen_ikh_data.sh $@ > +cmd_genikh = $(srctree)/kernel/gen_kheaders.sh $@ > $(obj)/kheaders_data.tar.xz: FORCE > $(call cmd,genikh) > > diff --git a/kernel/gen_ikh_data.sh b/kernel/gen_kheaders.sh > similarity index 98% > rename from kernel/gen_ikh_data.sh > rename to kernel/gen_kheaders.sh > index 591a94f7b387..581b83534587 100755 > --- a/kernel/gen_ikh_data.sh > +++ b/kernel/gen_kheaders.sh > @@ -2,7 +2,7 @@ > # SPDX-License-Identifier: GPL-2.0 > > # This script generates an archive consisting of kernel headers > -# for CONFIG_IKHEADERS_PROC. > +# for CONFIG_IKHEADERS. > set -e > spath="$(dirname "$(readlink -f "$0")")" > kroot="$spath/.." > diff --git a/kernel/kheaders.c b/kernel/kheaders.c > index 70ae6052920d..6a16f8f6898d 100644 > --- a/kernel/kheaders.c > +++ b/kernel/kheaders.c > @@ -8,9 +8,8 @@ > > #include > #include > -#include > +#include > #include > -#include > > /* > * Define kernel_headers_data and kernel_headers_data_end, within which the > @@ -31,39 +30,32 @@ extern char kernel_headers_data; > extern char kernel_headers_data_end; > > static ssize_t > -ikheaders_read_current(struct file *file, char __user *buf, > - size_t len, loff_t *offset) > +ikheaders_read(struct file *file, struct kobject *kobj, > + struct bin_attribute *bin_attr, > + char *buf, loff_t off, size_t len) > { > - return simple_read_from_buffer(buf, len, offset, > - &kernel_headers_data, > - &kernel_headers_data_end - > - &kernel_headers_data); > + memcpy(buf, &kernel_headers_data + off, len); > + return len; > } > > -static const struct file_operations ikheaders_file_ops = { > - .read = ikheaders_read_current, > - .llseek = default_llseek, > +static struct bin_attribute kheaders_attr __ro_after_init = { > + .attr = { > + .name = "kheaders.tar.xz", > + .mode = S_IRUGO, > + }, > + .read = &ikheaders_read, > }; > > static int __init ikheaders_init(void) > { > - struct proc_dir_entry *entry; > - > - /* create the current headers file */ > - entry = proc_create("kheaders.tar.xz", S_IRUGO, NULL, > - &ikheaders_file_ops); > - if (!entry) > - return -ENOMEM; > - > - proc_set_size(entry, > - &kernel_headers_data_end - > - &kernel_headers_data); > - return 0; > + kheaders_attr.size = (&kernel_headers_data_end - > + &kernel_headers_data); > + return sysfs_create_bin_file(kernel_kobj, &kheaders_attr); > } > > static void __exit ikheaders_cleanup(void) > { > - remove_proc_entry("kheaders.tar.xz", NULL); > + sysfs_remove_bin_file(kernel_kobj, &kheaders_attr); > } > > module_init(ikheaders_init); > -- > 2.21.0.1020.gf2820cf01a-goog -- Best Regards Masahiro Yamada