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From:   Petr Vorel <pvorel@suse.cz>
To:     linux-kernel@vger.kernel.org
Cc:     Petr Vorel <pvorel@suse.cz>,
        Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
        "Rafael J. Wysocki" <rafael@kernel.org>,
        David Sterba <dsterba@suse.com>
Subject: [PATCH v2 1/1] drivers/base/cpu: Print kernel arch
Date:   Fri, 29 Jul 2022 14:51:41 +0200
Message-Id: <20220729125141.12786-1-pvorel@suse.cz>
MIME-Version: 1.0
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Precedence: bulk

Print the machine hardware name (UTS_MACHINE) in /proc/sys/kernel/arch.

This helps people who debug kernel with initramfs with minimal
environment (i.e. without coreutils or even busybox) or allow to open
sysfs file instead of run 'uname -m' in high level languages.

Signed-off-by: Petr Vorel <pvorel@suse.cz>
---
 Documentation/admin-guide/sysctl/kernel.rst | 5 +++++
 kernel/utsname_sysctl.c                     | 7 +++++++
 2 files changed, 12 insertions(+)

diff --git a/Documentation/admin-guide/sysctl/kernel.rst b/Documentation/admin-guide/sysctl/kernel.rst
index ddccd1077462..70a0acf07101 100644
--- a/Documentation/admin-guide/sysctl/kernel.rst
+++ b/Documentation/admin-guide/sysctl/kernel.rst
@@ -65,6 +65,11 @@ combining the following values:
 4 s3_beep
 = =======
 
+arch
+====
+
+The machine hardware name, the same output as ``uname -m``
+(e.g. ``x86_64`` or ``aarch64``).
 
 auto_msgmni
 ===========
diff --git a/kernel/utsname_sysctl.c b/kernel/utsname_sysctl.c
index 4ca61d49885b..7ffdd2cd5ff9 100644
--- a/kernel/utsname_sysctl.c
+++ b/kernel/utsname_sysctl.c
@@ -73,6 +73,13 @@ static DEFINE_CTL_TABLE_POLL(hostname_poll);
 static DEFINE_CTL_TABLE_POLL(domainname_poll);
 
 static struct ctl_table uts_kern_table[] = {
+	{
+		.procname	= "arch",
+		.data		= init_uts_ns.name.machine,
+		.maxlen		= sizeof(init_uts_ns.name.machine),
+		.mode		= 0444,
+		.proc_handler	= proc_do_uts_string,
+	},
 	{
 		.procname	= "ostype",
 		.data		= init_uts_ns.name.sysname,
-- 
2.37.1