Merge tag 'sysctl-6.17-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/sysctl/sysctl

Pull sysctl updates from Joel Granados:

 - Move sysctls out of the kern_table array

   This is the final move of ctl_tables into their respective
   subsystems. Only 5 (out of the original 50) will remain in
   kernel/sysctl.c file; these handle either sysctl or common arch
   variables.

   By decentralizing sysctl registrations, subsystem maintainers regain
   control over their sysctl interfaces, improving maintainability and
   reducing the likelihood of merge conflicts.

 - docs: Remove false positives from check-sysctl-docs

   Stopped falsely identifying sysctls as undocumented or unimplemented
   in the check-sysctl-docs script. This script can now be used to
   automatically identify if documentation is missing.

* tag 'sysctl-6.17-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/sysctl/sysctl: (23 commits)
  docs: Downgrade arm64 & riscv from titles to comment
  docs: Replace spaces with tabs in check-sysctl-docs
  docs: Remove colon from ctltable title in vm.rst
  docs: Add awk section for ucount sysctl entries
  docs: Use skiplist when checking sysctl admin-guide
  docs: nixify check-sysctl-docs
  sysctl: rename kern_table -> sysctl_subsys_table
  kernel/sys.c: Move overflow{uid,gid} sysctl into kernel/sys.c
  uevent: mv uevent_helper into kobject_uevent.c
  sysctl: Removed unused variable
  sysctl: Nixify sysctl.sh
  sysctl: Remove superfluous includes from kernel/sysctl.c
  sysctl: Remove (very) old file changelog
  sysctl: Move sysctl_panic_on_stackoverflow to kernel/panic.c
  sysctl: move cad_pid into kernel/pid.c
  sysctl: Move tainted ctl_table into kernel/panic.c
  Input: sysrq: mv sysrq into drivers/tty/sysrq.c
  fork: mv threads-max into kernel/fork.c
  parisc/power: Move soft-power into power.c
  mm: move randomize_va_space into memory.c
  ...

Author: torvalds

Documentation/admin-guide/sysctl/kernel.rst

@@ -1014,30 +1014,26 @@ perf_user_access (arm64 and riscv only)
 
 Controls user space access for reading perf event counters.
 
-arm64
-=====
-
-The default value is 0 (access disabled).
+* for arm64
+  The default value is 0 (access disabled).
 
-When set to 1, user space can read performance monitor counter registers
-directly.
+  When set to 1, user space can read performance monitor counter registers
+  directly.
 
-See Documentation/arch/arm64/perf.rst for more information.
-
-riscv
-=====
+  See Documentation/arch/arm64/perf.rst for more information.
 
-When set to 0, user space access is disabled.
+* for riscv
+  When set to 0, user space access is disabled.
 
-The default value is 1, user space can read performance monitor counter
-registers through perf, any direct access without perf intervention will trigger
-an illegal instruction.
+  The default value is 1, user space can read performance monitor counter
+  registers through perf, any direct access without perf intervention will trigger
+  an illegal instruction.
 
-When set to 2, which enables legacy mode (user space has direct access to cycle
-and insret CSRs only). Note that this legacy value is deprecated and will be
-removed once all user space applications are fixed.
+  When set to 2, which enables legacy mode (user space has direct access to cycle
+  and insret CSRs only). Note that this legacy value is deprecated and will be
+  removed once all user space applications are fixed.
 
-Note that the time CSR is always directly accessible to all modes.
+  Note that the time CSR is always directly accessible to all modes.
 
 pid_max
 =======

Documentation/admin-guide/sysctl/vm.rst

@@ -465,8 +465,8 @@ The minimum value is 1 (1/1 -> 100%). The value less than 1 completely
 disables protection of the pages.
 
 
-max_map_count:
-==============
+max_map_count
+=============
 
 This file contains the maximum number of memory map areas a process
 may have. Memory map areas are used as a side-effect of calling
@@ -495,8 +495,8 @@ memory allocations.
 The default value depends on CONFIG_MEM_ALLOC_PROFILING_ENABLED_BY_DEFAULT.
 
 
-memory_failure_early_kill:
-==========================
+memory_failure_early_kill
+=========================
 
 Control how to kill processes when uncorrected memory error (typically
 a 2bit error in a memory module) is detected in the background by hardware

drivers/parisc/power.c

@@ -83,7 +83,25 @@ static struct task_struct *power_task;
 #define SYSCTL_FILENAME	"sys/kernel/power"
 
 /* soft power switch enabled/disabled */
-int pwrsw_enabled __read_mostly = 1;
+static int pwrsw_enabled __read_mostly = 1;
+
+static const struct ctl_table power_sysctl_table[] = {
+	{
+		.procname	= "soft-power",
+		.data		= &pwrsw_enabled,
+		.maxlen		= sizeof(int),
+		.mode		= 0644,
+		.proc_handler	= proc_dointvec,
+	},
+};
+
+static int __init init_power_sysctl(void)
+{
+	register_sysctl_init("kernel", power_sysctl_table);
+	return 0;
+}
+
+arch_initcall(init_power_sysctl);
 
 /* main kernel thread worker. It polls the button state */
 static int kpowerswd(void *param)

drivers/tty/sysrq.c

@@ -1120,6 +1120,47 @@ int sysrq_toggle_support(int enable_mask)
 }
 EXPORT_SYMBOL_GPL(sysrq_toggle_support);
 
+static int sysrq_sysctl_handler(const struct ctl_table *table, int write,
+				void *buffer, size_t *lenp, loff_t *ppos)
+{
+	int tmp, ret;
+	struct ctl_table t = *table;
+
+	tmp = sysrq_mask();
+	t.data = &tmp;
+
+	/*
+	 * Behaves like do_proc_dointvec as t does not have min nor max.
+	 */
+	ret = proc_dointvec_minmax(&t, write, buffer, lenp, ppos);
+
+	if (ret || !write)
+		return ret;
+
+	if (write)
+		sysrq_toggle_support(tmp);
+
+	return 0;
+}
+
+static const struct ctl_table sysrq_sysctl_table[] = {
+	{
+		.procname	= "sysrq",
+		.data		= NULL,
+		.maxlen		= sizeof(int),
+		.mode		= 0644,
+		.proc_handler	= sysrq_sysctl_handler,
+	},
+};
+
+static int __init init_sysrq_sysctl(void)
+{
+	register_sysctl_init("kernel", sysrq_sysctl_table);
+	return 0;
+}
+
+subsys_initcall(init_sysrq_sysctl);
+
 static int __sysrq_swap_key_ops(u8 key, const struct sysrq_key_op *insert_op_p,
 				const struct sysrq_key_op *remove_op_p)
 {

include/linux/kmod.h

@@ -14,10 +14,7 @@
 #include <linux/workqueue.h>
 #include <linux/sysctl.h>
 
-#define KMOD_PATH_LEN 256
-
 #ifdef CONFIG_MODULES
-extern char modprobe_path[]; /* for sysctl */
 /* modprobe exit status on success, -ve on error.  Return value
  * usually useless though. */
 extern __printf(2, 3)

include/linux/module.h

@@ -304,7 +304,6 @@ struct notifier_block;
 
 #ifdef CONFIG_MODULES
 
-extern int modules_disabled; /* for sysctl */
 /* Get/put a kernel symbol (calls must be symmetric) */
 void *__symbol_get(const char *symbol);
 void *__symbol_get_gpl(const char *symbol);

include/linux/panic.h

@@ -25,8 +25,6 @@ extern int panic_on_warn;
 extern unsigned long panic_on_taint;
 extern bool panic_on_taint_nousertaint;
 
-extern int sysctl_panic_on_rcu_stall;
-extern int sysctl_max_rcu_stall_to_panic;
 extern int sysctl_panic_on_stackoverflow;
 
 extern bool crash_kexec_post_notifiers;

include/linux/rtmutex.h

@@ -18,7 +18,7 @@
 #include <linux/rbtree_types.h>
 #include <linux/spinlock_types_raw.h>
 
-extern int max_lock_depth; /* for sysctl */
+extern int max_lock_depth;
 
 struct rt_mutex_base {
 	raw_spinlock_t		wait_lock;

include/linux/sysctl.h

@@ -242,9 +242,7 @@ int do_proc_douintvec(const struct ctl_table *table, int write,
 				  int write, void *data),
 		      void *data);
 
-extern int pwrsw_enabled;
 extern int unaligned_enabled;
-extern int unaligned_dump_stack;
 extern int no_unaligned_warning;
 
 #else /* CONFIG_SYSCTL */
@@ -285,7 +283,4 @@ static inline bool sysctl_is_alias(char *param)
 }
 #endif /* CONFIG_SYSCTL */
 
-int sysctl_max_threads(const struct ctl_table *table, int write, void *buffer,
-		size_t *lenp, loff_t *ppos);
-
 #endif /* _LINUX_SYSCTL_H */

kernel/fork.c

@@ -3219,7 +3219,7 @@ int unshare_files(void)
 	return 0;
 }
 
-int sysctl_max_threads(const struct ctl_table *table, int write,
+static int sysctl_max_threads(const struct ctl_table *table, int write,
 		       void *buffer, size_t *lenp, loff_t *ppos)
 {
 	struct ctl_table t;
@@ -3241,3 +3241,21 @@ int sysctl_max_threads(const struct ctl_table *table, int write,
 
 	return 0;
 }
+
+static const struct ctl_table fork_sysctl_table[] = {
+	{
+		.procname	= "threads-max",
+		.data		= NULL,
+		.maxlen		= sizeof(int),
+		.mode		= 0644,
+		.proc_handler	= sysctl_max_threads,
+	},
+};
+
+static int __init init_fork_sysctl(void)
+{
+	register_sysctl_init("kernel", fork_sysctl_table);
+	return 0;
+}
+
+subsys_initcall(init_fork_sysctl);