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 <linux@weissschuh.net>
Signed-off-by: Thomas Weißschuh <linux@weissschuh.net>
Co-developed-by: Joel Granados <j.granados@samsung.com>
Signed-off-by: Joel Granados <j.granados@samsung.com>

3 files changed, 19 insertions, 19 deletions

diff --git a/net/ipv4/devinet.c b/net/ipv4/devinet.c
index d09f557eaa77..d96f3e452fef 100644
--- a/net/ipv4/devinet.c
+++ b/net/ipv4/devinet.c
@@ -2390,7 +2390,7 @@ static int devinet_conf_ifindex(struct net *net, struct ipv4_devconf *cnf)
 	}
 }
 
-static int devinet_conf_proc(struct ctl_table *ctl, int write,
+static int devinet_conf_proc(const struct ctl_table *ctl, int write,
 			     void *buffer, size_t *lenp, loff_t *ppos)
 {
 	int old_value = *(int *)ctl->data;
@@ -2442,7 +2442,7 @@ static int devinet_conf_proc(struct ctl_table *ctl, int write,
 	return ret;
 }
 
-static int devinet_sysctl_forward(struct ctl_table *ctl, int write,
+static int devinet_sysctl_forward(const struct ctl_table *ctl, int write,
 				  void *buffer, size_t *lenp, loff_t *ppos)
 {
 	int *valp = ctl->data;
@@ -2489,7 +2489,7 @@ static int devinet_sysctl_forward(struct ctl_table *ctl, int write,
 	return ret;
 }
 
-static int ipv4_doint_and_flush(struct ctl_table *ctl, int write,
+static int ipv4_doint_and_flush(const struct ctl_table *ctl, int write,
 				void *buffer, size_t *lenp, loff_t *ppos)
 {
 	int *valp = ctl->data;
diff --git a/net/ipv4/route.c b/net/ipv4/route.c
index 5090912533d6..5cc476ee8ced 100644
--- a/net/ipv4/route.c
+++ b/net/ipv4/route.c
@@ -3388,7 +3388,7 @@ static int ip_rt_gc_min_interval __read_mostly	= HZ / 2;
 static int ip_rt_gc_elasticity __read_mostly	= 8;
 static int ip_min_valid_pmtu __read_mostly	= IPV4_MIN_MTU;
 
-static int ipv4_sysctl_rtcache_flush(struct ctl_table *__ctl, int write,
+static int ipv4_sysctl_rtcache_flush(const struct ctl_table *__ctl, int write,
 		void *buffer, size_t *lenp, loff_t *ppos)
 {
 	struct net *net = (struct net *)__ctl->extra1;
diff --git a/net/ipv4/sysctl_net_ipv4.c b/net/ipv4/sysctl_net_ipv4.c
index 9140d20eb2d4..4af0c234d8d7 100644
--- a/net/ipv4/sysctl_net_ipv4.c
+++ b/net/ipv4/sysctl_net_ipv4.c
@@ -62,7 +62,7 @@ static void set_local_port_range(struct net *net, unsigned int low, unsigned int
 }
 
 /* Validate changes from /proc interface. */
-static int ipv4_local_port_range(struct ctl_table *table, int write,
+static int ipv4_local_port_range(const struct ctl_table *table, int write,
 				 void *buffer, size_t *lenp, loff_t *ppos)
 {
 	struct net *net = table->data;
@@ -96,7 +96,7 @@ static int ipv4_local_port_range(struct ctl_table *table, int write,
 }
 
 /* Validate changes from /proc interface. */
-static int ipv4_privileged_ports(struct ctl_table *table, int write,
+static int ipv4_privileged_ports(const struct ctl_table *table, int write,
 				void *buffer, size_t *lenp, loff_t *ppos)
 {
 	struct net *net = container_of(table->data, struct net,
@@ -159,7 +159,7 @@ static void set_ping_group_range(const struct ctl_table *table,
 }
 
 /* Validate changes from /proc interface. */
-static int ipv4_ping_group_range(struct ctl_table *table, int write,
+static int ipv4_ping_group_range(const struct ctl_table *table, int write,
 				 void *buffer, size_t *lenp, loff_t *ppos)
 {
 	struct user_namespace *user_ns = current_user_ns();
@@ -194,7 +194,7 @@ static int ipv4_ping_group_range(struct ctl_table *table, int write,
 	return ret;
 }
 
-static int ipv4_fwd_update_priority(struct ctl_table *table, int write,
+static int ipv4_fwd_update_priority(const struct ctl_table *table, int write,
 				    void *buffer, size_t *lenp, loff_t *ppos)
 {
 	struct net *net;
@@ -210,7 +210,7 @@ static int ipv4_fwd_update_priority(struct ctl_table *table, int write,
 	return ret;
 }
 
-static int proc_tcp_congestion_control(struct ctl_table *ctl, int write,
+static int proc_tcp_congestion_control(const struct ctl_table *ctl, int write,
 				       void *buffer, size_t *lenp, loff_t *ppos)
 {
 	struct net *net = container_of(ctl->data, struct net,
@@ -230,7 +230,7 @@ static int proc_tcp_congestion_control(struct ctl_table *ctl, int write,
 	return ret;
 }
 
-static int proc_tcp_available_congestion_control(struct ctl_table *ctl,
+static int proc_tcp_available_congestion_control(const struct ctl_table *ctl,
 						 int write, void *buffer,
 						 size_t *lenp, loff_t *ppos)
 {
@@ -246,7 +246,7 @@ static int proc_tcp_available_congestion_control(struct ctl_table *ctl,
 	return ret;
 }
 
-static int proc_allowed_congestion_control(struct ctl_table *ctl,
+static int proc_allowed_congestion_control(const struct ctl_table *ctl,
 					   int write, void *buffer,
 					   size_t *lenp, loff_t *ppos)
 {
@@ -283,7 +283,7 @@ static int sscanf_key(char *buf, __le32 *key)
 	return ret;
 }
 
-static int proc_tcp_fastopen_key(struct ctl_table *table, int write,
+static int proc_tcp_fastopen_key(const struct ctl_table *table, int write,
 				 void *buffer, size_t *lenp, loff_t *ppos)
 {
 	struct net *net = container_of(table->data, struct net,
@@ -354,7 +354,7 @@ bad_key:
 	return ret;
 }
 
-static int proc_tfo_blackhole_detect_timeout(struct ctl_table *table,
+static int proc_tfo_blackhole_detect_timeout(const struct ctl_table *table,
 					     int write, void *buffer,
 					     size_t *lenp, loff_t *ppos)
 {
@@ -369,7 +369,7 @@ static int proc_tfo_blackhole_detect_timeout(struct ctl_table *table,
 	return ret;
 }
 
-static int proc_tcp_available_ulp(struct ctl_table *ctl,
+static int proc_tcp_available_ulp(const struct ctl_table *ctl,
 				  int write, void *buffer, size_t *lenp,
 				  loff_t *ppos)
 {
@@ -386,7 +386,7 @@ static int proc_tcp_available_ulp(struct ctl_table *ctl,
 	return ret;
 }
 
-static int proc_tcp_ehash_entries(struct ctl_table *table, int write,
+static int proc_tcp_ehash_entries(const struct ctl_table *table, int write,
 				  void *buffer, size_t *lenp, loff_t *ppos)
 {
 	struct net *net = container_of(table->data, struct net,
@@ -410,7 +410,7 @@ static int proc_tcp_ehash_entries(struct ctl_table *table, int write,
 	return proc_dointvec(&tbl, write, buffer, lenp, ppos);
 }
 
-static int proc_udp_hash_entries(struct ctl_table *table, int write,
+static int proc_udp_hash_entries(const struct ctl_table *table, int write,
 				 void *buffer, size_t *lenp, loff_t *ppos)
 {
 	struct net *net = container_of(table->data, struct net,
@@ -434,7 +434,7 @@ static int proc_udp_hash_entries(struct ctl_table *table, int write,
 }
 
 #ifdef CONFIG_IP_ROUTE_MULTIPATH
-static int proc_fib_multipath_hash_policy(struct ctl_table *table, int write,
+static int proc_fib_multipath_hash_policy(const struct ctl_table *table, int write,
 					  void *buffer, size_t *lenp,
 					  loff_t *ppos)
 {
@@ -449,7 +449,7 @@ static int proc_fib_multipath_hash_policy(struct ctl_table *table, int write,
 	return ret;
 }
 
-static int proc_fib_multipath_hash_fields(struct ctl_table *table, int write,
+static int proc_fib_multipath_hash_fields(const struct ctl_table *table, int write,
 					  void *buffer, size_t *lenp,
 					  loff_t *ppos)
 {
@@ -484,7 +484,7 @@ static void proc_fib_multipath_hash_set_seed(struct net *net, u32 user_seed)
 	WRITE_ONCE(net->ipv4.sysctl_fib_multipath_hash_seed, new);
 }
 
-static int proc_fib_multipath_hash_seed(struct ctl_table *table, int write,
+static int proc_fib_multipath_hash_seed(const struct ctl_table *table, int write,
 					void *buffer, size_t *lenp,
 					loff_t *ppos)
 {