sysctl: treewide: constify the ctl_table argument of proc_handlers

const qualify the struct ctl_table argument in the proc_handler function
signatures. This is a prerequisite to moving the static ctl_table
structs into .rodata data which will ensure that proc_handler function
pointers cannot be modified.

This patch has been generated by the following coccinelle script:

```
  virtual patch

  @r1@
  identifier ctl, write, buffer, lenp, ppos;
  identifier func !~ "appldata_(timer|interval)_handler|sched_(rt|rr)_handler|rds_tcp_skbuf_handler|proc_sctp_do_(hmac_alg|rto_min|rto_max|udp_port|alpha_beta|auth|probe_interval)";
  @@

  int func(
  - struct ctl_table *ctl
  + const struct ctl_table *ctl
    ,int write, void *buffer, size_t *lenp, loff_t *ppos);

  @r2@
  identifier func, ctl, write, buffer, lenp, ppos;
  @@

  int func(
  - struct ctl_table *ctl
  + const struct ctl_table *ctl
    ,int write, void *buffer, size_t *lenp, loff_t *ppos)
  { ... }

  @r3@
  identifier func;
  @@

  int func(
  - struct ctl_table *
  + const struct ctl_table *
    ,int , void *, size_t *, loff_t *);

  @r4@
  identifier func, ctl;
  @@

  int func(
  - struct ctl_table *ctl
  + const struct ctl_table *ctl
    ,int , void *, size_t *, loff_t *);

  @R5@
  identifier func, write, buffer, lenp, ppos;
  @@

  int func(
  - struct ctl_table *
  + const struct ctl_table *
    ,int write, void *buffer, size_t *lenp, loff_t *ppos);

```

* Code formatting was adjusted in xfs_sysctl.c to comply with code
  conventions. The xfs_stats_clear_proc_handler,
  xfs_panic_mask_proc_handler and xfs_deprecated_dointvec_minmax where
  adjusted.

* The ctl_table argument in proc_watchdog_common was const qualified.
  This is called from a proc_handler itself and is calling back into
  another proc_handler, making it necessary to change it as part of the
  proc_handler migration.

Co-developed-by: Thomas Weißschuh <[email protected]>
Signed-off-by: Thomas Weißschuh <[email protected]>
Co-developed-by: Joel Granados <[email protected]>
Signed-off-by: Joel Granados <[email protected]>

Author: Joelgranados

arch/arm64/kernel/armv8_deprecated.c

@@ -507,7 +507,7 @@ static int update_insn_emulation_mode(struct insn_emulation *insn,
 	return ret;
 }
 
-static int emulation_proc_handler(struct ctl_table *table, int write,
+static int emulation_proc_handler(const struct ctl_table *table, int write,
 				  void *buffer, size_t *lenp,
 				  loff_t *ppos)
 {

arch/arm64/kernel/fpsimd.c

@@ -535,7 +535,7 @@ static unsigned int find_supported_vector_length(enum vec_type type,
 
 #if defined(CONFIG_ARM64_SVE) && defined(CONFIG_SYSCTL)
 
-static int vec_proc_do_default_vl(struct ctl_table *table, int write,
+static int vec_proc_do_default_vl(const struct ctl_table *table, int write,
 				  void *buffer, size_t *lenp, loff_t *ppos)
 {
 	struct vl_info *info = table->extra1;

arch/s390/appldata/appldata_base.c

@@ -46,9 +46,9 @@
  * /proc entries (sysctl)
  */
 static const char appldata_proc_name[APPLDATA_PROC_NAME_LENGTH] = "appldata";
-static int appldata_timer_handler(struct ctl_table *ctl, int write,
+static int appldata_timer_handler(const struct ctl_table *ctl, int write,
 				  void *buffer, size_t *lenp, loff_t *ppos);
-static int appldata_interval_handler(struct ctl_table *ctl, int write,
+static int appldata_interval_handler(const struct ctl_table *ctl, int write,
 				     void *buffer, size_t *lenp, loff_t *ppos);
 
 static struct ctl_table_header *appldata_sysctl_header;
@@ -199,7 +199,7 @@ static void __appldata_vtimer_setup(int cmd)
  * Start/Stop timer, show status of timer (0 = not active, 1 = active)
  */
 static int
-appldata_timer_handler(struct ctl_table *ctl, int write,
+appldata_timer_handler(const struct ctl_table *ctl, int write,
 			   void *buffer, size_t *lenp, loff_t *ppos)
 {
 	int timer_active = appldata_timer_active;
@@ -232,7 +232,7 @@ appldata_timer_handler(struct ctl_table *ctl, int write,
  * current timer interval.
  */
 static int
-appldata_interval_handler(struct ctl_table *ctl, int write,
+appldata_interval_handler(const struct ctl_table *ctl, int write,
 			   void *buffer, size_t *lenp, loff_t *ppos)
 {
 	int interval = appldata_interval;
@@ -262,7 +262,7 @@ appldata_interval_handler(struct ctl_table *ctl, int write,
  * monitoring (0 = not in process, 1 = in process)
  */
 static int
-appldata_generic_handler(struct ctl_table *ctl, int write,
+appldata_generic_handler(const struct ctl_table *ctl, int write,
 			   void *buffer, size_t *lenp, loff_t *ppos)
 {
 	struct appldata_ops *ops = NULL, *tmp_ops;

arch/s390/kernel/debug.c

@@ -954,7 +954,7 @@ static int debug_active = 1;
  * always allow read, allow write only if debug_stoppable is set or
  * if debug_active is already off
  */
-static int s390dbf_procactive(struct ctl_table *table, int write,
+static int s390dbf_procactive(const struct ctl_table *table, int write,
 			      void *buffer, size_t *lenp, loff_t *ppos)
 {
 	if (!write || debug_stoppable || !debug_active)

arch/s390/kernel/topology.c

@@ -594,7 +594,7 @@ static int __init topology_setup(char *str)
 }
 early_param("topology", topology_setup);
 
-static int topology_ctl_handler(struct ctl_table *ctl, int write,
+static int topology_ctl_handler(const struct ctl_table *ctl, int write,
 				void *buffer, size_t *lenp, loff_t *ppos)
 {
 	int enabled = topology_is_enabled();

arch/s390/mm/cmm.c

@@ -243,7 +243,7 @@ static int cmm_skip_blanks(char *cp, char **endp)
 	return str != cp;
 }
 
-static int cmm_pages_handler(struct ctl_table *ctl, int write,
+static int cmm_pages_handler(const struct ctl_table *ctl, int write,
 			     void *buffer, size_t *lenp, loff_t *ppos)
 {
 	long nr = cmm_get_pages();
@@ -262,7 +262,7 @@ static int cmm_pages_handler(struct ctl_table *ctl, int write,
 	return 0;
 }
 
-static int cmm_timed_pages_handler(struct ctl_table *ctl, int write,
+static int cmm_timed_pages_handler(const struct ctl_table *ctl, int write,
 				   void *buffer, size_t *lenp,
 				   loff_t *ppos)
 {
@@ -282,7 +282,7 @@ static int cmm_timed_pages_handler(struct ctl_table *ctl, int write,
 	return 0;
 }
 
-static int cmm_timeout_handler(struct ctl_table *ctl, int write,
+static int cmm_timeout_handler(const struct ctl_table *ctl, int write,
 			       void *buffer, size_t *lenp, loff_t *ppos)
 {
 	char buf[64], *p;

arch/x86/kernel/itmt.c

@@ -38,7 +38,7 @@ static bool __read_mostly sched_itmt_capable;
  */
 unsigned int __read_mostly sysctl_sched_itmt_enabled;
 
-static int sched_itmt_update_handler(struct ctl_table *table, int write,
+static int sched_itmt_update_handler(const struct ctl_table *table, int write,
 				     void *buffer, size_t *lenp, loff_t *ppos)
 {
 	unsigned int old_sysctl;

drivers/cdrom/cdrom.c

@@ -3473,7 +3473,7 @@ static int cdrom_print_info(const char *header, int val, char *info,
 	return 0;
 }
 
-static int cdrom_sysctl_info(struct ctl_table *ctl, int write,
+static int cdrom_sysctl_info(const struct ctl_table *ctl, int write,
                            void *buffer, size_t *lenp, loff_t *ppos)
 {
 	int pos;
@@ -3586,7 +3586,7 @@ static void cdrom_update_settings(void)
 	mutex_unlock(&cdrom_mutex);
 }
 
-static int cdrom_sysctl_handler(struct ctl_table *ctl, int write,
+static int cdrom_sysctl_handler(const struct ctl_table *ctl, int write,
 				void *buffer, size_t *lenp, loff_t *ppos)
 {
 	int ret;

drivers/char/random.c

@@ -1620,7 +1620,7 @@ static u8 sysctl_bootid[UUID_SIZE];
  * UUID. The difference is in whether table->data is NULL; if it is,
  * then a new UUID is generated and returned to the user.
  */
-static int proc_do_uuid(struct ctl_table *table, int write, void *buf,
+static int proc_do_uuid(const struct ctl_table *table, int write, void *buf,
 			size_t *lenp, loff_t *ppos)
 {
 	u8 tmp_uuid[UUID_SIZE], *uuid;
@@ -1651,7 +1651,7 @@ static int proc_do_uuid(struct ctl_table *table, int write, void *buf,
 }
 
 /* The same as proc_dointvec, but writes don't change anything. */
-static int proc_do_rointvec(struct ctl_table *table, int write, void *buf,
+static int proc_do_rointvec(const struct ctl_table *table, int write, void *buf,
 			    size_t *lenp, loff_t *ppos)
 {
 	return write ? 0 : proc_dointvec(table, 0, buf, lenp, ppos);

drivers/macintosh/mac_hid.c

@@ -183,7 +183,7 @@ static void mac_hid_stop_emulation(void)
 	mac_hid_destroy_emumouse();
 }
 
-static int mac_hid_toggle_emumouse(struct ctl_table *table, int write,
+static int mac_hid_toggle_emumouse(const struct ctl_table *table, int write,
 				   void *buffer, size_t *lenp, loff_t *ppos)
 {
 	int *valp = table->data;