From 2c0ff03eaa0578b222cbf8a51ad1b6e29d6e2760 Mon Sep 17 00:00:00 2001
From: Xiaoming Ni <nixiaoming@huawei.com>
Date: Fri, 21 Jan 2022 22:12:33 -0800
Subject: [PATCH] printk: move printk sysctl to printk/sysctl.c
References: bnc#1189998 (PREEMPT_RT prerequisite backports)
Patch-mainline: v5.17-rc1
Git-commit: faaa357a55e03490fb280ac211be2298e635b220
kernel/sysctl.c is a kitchen sink where everyone leaves their dirty
dishes, this makes it very difficult to maintain.
To help with this maintenance let's start by moving sysctls to places
where they actually belong. The proc sysctl maintainers do not want to
know what sysctl knobs you wish to add for your own piece of code, we
just care about the core logic.
So move printk sysctl from kernel/sysctl.c to kernel/printk/sysctl.c.
Use register_sysctl() to register the sysctl interface.
[mcgrof@kernel.org: fixed compile issues when PRINTK is not set, commit log update]
Link: https://lkml.kernel.org/r/20211124231435.1445213-6-mcgrof@kernel.org
Signed-off-by: Xiaoming Ni <nixiaoming@huawei.com>
Signed-off-by: Luis Chamberlain <mcgrof@kernel.org>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Amir Goldstein <amir73il@gmail.com>
Cc: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Cc: Antti Palosaari <crope@iki.fi>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Benjamin LaHaise <bcrl@kvack.org>
Cc: Clemens Ladisch <clemens@ladisch.de>
Cc: David Airlie <airlied@linux.ie>
Cc: Douglas Gilbert <dgilbert@interlog.com>
Cc: Eric Biederman <ebiederm@xmission.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Iurii Zaikin <yzaikin@google.com>
Cc: James E.J. Bottomley <jejb@linux.ibm.com>
Cc: Jani Nikula <jani.nikula@intel.com>
Cc: Jani Nikula <jani.nikula@linux.intel.com>
Cc: Jan Kara <jack@suse.cz>
Cc: Joel Becker <jlbec@evilplan.org>
Cc: John Ogness <john.ogness@linutronix.de>
Cc: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
Cc: Joseph Qi <joseph.qi@linux.alibaba.com>
Cc: Julia Lawall <julia.lawall@inria.fr>
Cc: Kees Cook <keescook@chromium.org>
Cc: Lukas Middendorf <kernel@tuxforce.de>
Cc: Mark Fasheh <mark@fasheh.com>
Cc: Martin K. Petersen <martin.petersen@oracle.com>
Cc: Paul Turner <pjt@google.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Petr Mladek <pmladek@suse.com>
Cc: Phillip Potter <phil@philpotter.co.uk>
Cc: Qing Wang <wangqing@vivo.com>
Cc: "Rafael J. Wysocki" <rafael@kernel.org>
Cc: Rodrigo Vivi <rodrigo.vivi@intel.com>
Cc: Sebastian Reichel <sre@kernel.org>
Cc: Sergey Senozhatsky <senozhatsky@chromium.org>
Cc: Stephen Kitt <steve@sk2.org>
Cc: Steven Rostedt (VMware) <rostedt@goodmis.org>
Cc: Suren Baghdasaryan <surenb@google.com>
Cc: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Cc: "Theodore Ts'o" <tytso@mit.edu>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Mel Gorman <mgorman@suse.de>
---
kernel/printk/Makefile | 5 ++-
kernel/printk/internal.h | 6 ++++
kernel/printk/printk.c | 1 +
kernel/printk/sysctl.c | 85 ++++++++++++++++++++++++++++++++++++++++++++++++
kernel/sysctl.c | 68 --------------------------------------
5 files changed, 96 insertions(+), 69 deletions(-)
diff --git a/kernel/printk/Makefile b/kernel/printk/Makefile
index d118739874c0..f5b388e810b9 100644
--- a/kernel/printk/Makefile
+++ b/kernel/printk/Makefile
@@ -2,5 +2,8 @@
obj-y = printk.o
obj-$(CONFIG_PRINTK) += printk_safe.o
obj-$(CONFIG_A11Y_BRAILLE_CONSOLE) += braille.o
-obj-$(CONFIG_PRINTK) += printk_ringbuffer.o
obj-$(CONFIG_PRINTK_INDEX) += index.o
+
+obj-$(CONFIG_PRINTK) += printk_support.o
+printk_support-y := printk_ringbuffer.o
+printk_support-$(CONFIG_SYSCTL) += sysctl.o
diff --git a/kernel/printk/internal.h b/kernel/printk/internal.h
index 9f3ed2fdb721..6b1c4b399845 100644
--- a/kernel/printk/internal.h
+++ b/kernel/printk/internal.h
@@ -4,6 +4,12 @@
*/
#include <linux/percpu.h>
+#if defined(CONFIG_PRINTK) && defined(CONFIG_SYSCTL)
+void __init printk_sysctl_init(void);
+#else
+#define printk_sysctl_init() do { } while (0)
+#endif
+
#ifdef CONFIG_PRINTK
/* Flags for a single printk record. */
diff --git a/kernel/printk/printk.c b/kernel/printk/printk.c
index 919cb99e908e..d70129c3f0c7 100644
--- a/kernel/printk/printk.c
+++ b/kernel/printk/printk.c
@@ -3225,6 +3225,7 @@ static int __init printk_late_init(void)
ret = cpuhp_setup_state_nocalls(CPUHP_AP_ONLINE_DYN, "printk:online",
console_cpu_notify, NULL);
WARN_ON(ret < 0);
+ printk_sysctl_init();
return 0;
}
late_initcall(printk_late_init);
diff --git a/kernel/printk/sysctl.c b/kernel/printk/sysctl.c
new file mode 100644
index 000000000000..653ae04aab7f
--- /dev/null
+++ b/kernel/printk/sysctl.c
@@ -0,0 +1,85 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * sysctl.c: General linux system control interface
+ */
+
+#include <linux/sysctl.h>
+#include <linux/printk.h>
+#include <linux/capability.h>
+#include <linux/ratelimit.h>
+#include "internal.h"
+
+static const int ten_thousand = 10000;
+
+static int proc_dointvec_minmax_sysadmin(struct ctl_table *table, int write,
+ void __user *buffer, size_t *lenp, loff_t *ppos)
+{
+ if (write && !capable(CAP_SYS_ADMIN))
+ return -EPERM;
+
+ return proc_dointvec_minmax(table, write, buffer, lenp, ppos);
+}
+
+static struct ctl_table printk_sysctls[] = {
+ {
+ .procname = "printk",
+ .data = &console_loglevel,
+ .maxlen = 4*sizeof(int),
+ .mode = 0644,
+ .proc_handler = proc_dointvec,
+ },
+ {
+ .procname = "printk_ratelimit",
+ .data = &printk_ratelimit_state.interval,
+ .maxlen = sizeof(int),
+ .mode = 0644,
+ .proc_handler = proc_dointvec_jiffies,
+ },
+ {
+ .procname = "printk_ratelimit_burst",
+ .data = &printk_ratelimit_state.burst,
+ .maxlen = sizeof(int),
+ .mode = 0644,
+ .proc_handler = proc_dointvec,
+ },
+ {
+ .procname = "printk_delay",
+ .data = &printk_delay_msec,
+ .maxlen = sizeof(int),
+ .mode = 0644,
+ .proc_handler = proc_dointvec_minmax,
+ .extra1 = SYSCTL_ZERO,
+ .extra2 = (void *)&ten_thousand,
+ },
+ {
+ .procname = "printk_devkmsg",
+ .data = devkmsg_log_str,
+ .maxlen = DEVKMSG_STR_MAX_SIZE,
+ .mode = 0644,
+ .proc_handler = devkmsg_sysctl_set_loglvl,
+ },
+ {
+ .procname = "dmesg_restrict",
+ .data = &dmesg_restrict,
+ .maxlen = sizeof(int),
+ .mode = 0644,
+ .proc_handler = proc_dointvec_minmax_sysadmin,
+ .extra1 = SYSCTL_ZERO,
+ .extra2 = SYSCTL_ONE,
+ },
+ {
+ .procname = "kptr_restrict",
+ .data = &kptr_restrict,
+ .maxlen = sizeof(int),
+ .mode = 0644,
+ .proc_handler = proc_dointvec_minmax_sysadmin,
+ .extra1 = SYSCTL_ZERO,
+ .extra2 = SYSCTL_TWO,
+ },
+ {}
+};
+
+void __init printk_sysctl_init(void)
+{
+ register_sysctl_init("kernel", printk_sysctls);
+}
diff --git a/kernel/sysctl.c b/kernel/sysctl.c
index e241a313513c..05089ad847eb 100644
--- a/kernel/sysctl.c
+++ b/kernel/sysctl.c
@@ -913,17 +913,6 @@ static int proc_taint(struct ctl_table *table, int write,
return err;
}
-#ifdef CONFIG_PRINTK
-static int proc_dointvec_minmax_sysadmin(struct ctl_table *table, int write,
- void *buffer, size_t *lenp, loff_t *ppos)
-{
- if (write && !capable(CAP_SYS_ADMIN))
- return -EPERM;
-
- return proc_dointvec_minmax(table, write, buffer, lenp, ppos);
-}
-#endif
-
/**
* struct do_proc_dointvec_minmax_conv_param - proc_dointvec_minmax() range checking structure
* @min: pointer to minimum allowable value
@@ -2329,63 +2318,6 @@ static struct ctl_table kern_table[] = {
.mode = 0644,
.proc_handler = proc_doulongvec_minmax,
},
-#if defined CONFIG_PRINTK
- {
- .procname = "printk",
- .data = &console_loglevel,
- .maxlen = 4*sizeof(int),
- .mode = 0644,
- .proc_handler = proc_dointvec,
- },
- {
- .procname = "printk_ratelimit",
- .data = &printk_ratelimit_state.interval,
- .maxlen = sizeof(int),
- .mode = 0644,
- .proc_handler = proc_dointvec_jiffies,
- },
- {
- .procname = "printk_ratelimit_burst",
- .data = &printk_ratelimit_state.burst,
- .maxlen = sizeof(int),
- .mode = 0644,
- .proc_handler = proc_dointvec,
- },
- {
- .procname = "printk_delay",
- .data = &printk_delay_msec,
- .maxlen = sizeof(int),
- .mode = 0644,
- .proc_handler = proc_dointvec_minmax,
- .extra1 = SYSCTL_ZERO,
- .extra2 = (void *)&ten_thousand,
- },
- {
- .procname = "printk_devkmsg",
- .data = devkmsg_log_str,
- .maxlen = DEVKMSG_STR_MAX_SIZE,
- .mode = 0644,
- .proc_handler = devkmsg_sysctl_set_loglvl,
- },
- {
- .procname = "dmesg_restrict",
- .data = &dmesg_restrict,
- .maxlen = sizeof(int),
- .mode = 0644,
- .proc_handler = proc_dointvec_minmax_sysadmin,
- .extra1 = SYSCTL_ZERO,
- .extra2 = SYSCTL_ONE,
- },
- {
- .procname = "kptr_restrict",
- .data = &kptr_restrict,
- .maxlen = sizeof(int),
- .mode = 0644,
- .proc_handler = proc_dointvec_minmax_sysadmin,
- .extra1 = SYSCTL_ZERO,
- .extra2 = SYSCTL_TWO,
- },
-#endif
{
.procname = "ngroups_max",
.data = &ngroups_max,