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>

10 files changed, 12 insertions, 12 deletions

diff --git a/fs/coredump.c b/fs/coredump.c
index 4dc5140bac3f..7f12ff6ad1d3 100644
--- a/fs/coredump.c
+++ b/fs/coredump.c
@@ -991,7 +991,7 @@ void validate_coredump_safety(void)
 	}
 }
 
-static int proc_dostring_coredump(struct ctl_table *table, int write,
+static int proc_dostring_coredump(const struct ctl_table *table, int write,
 		  void *buffer, size_t *lenp, loff_t *ppos)
 {
 	int error = proc_dostring(table, write, buffer, lenp, ppos);
diff --git a/fs/dcache.c b/fs/dcache.c
index 8bdc278a0205..3d8daaecb6d1 100644
--- a/fs/dcache.c
+++ b/fs/dcache.c
@@ -177,7 +177,7 @@ static long get_nr_dentry_negative(void)
 	return sum < 0 ? 0 : sum;
 }
 
-static int proc_nr_dentry(struct ctl_table *table, int write, void *buffer,
+static int proc_nr_dentry(const struct ctl_table *table, int write, void *buffer,
 			  size_t *lenp, loff_t *ppos)
 {
 	dentry_stat.nr_dentry = get_nr_dentry();
diff --git a/fs/drop_caches.c b/fs/drop_caches.c
index b9575957a7c2..d45ef541d848 100644
--- a/fs/drop_caches.c
+++ b/fs/drop_caches.c
@@ -48,7 +48,7 @@ static void drop_pagecache_sb(struct super_block *sb, void *unused)
 	iput(toput_inode);
 }
 
-int drop_caches_sysctl_handler(struct ctl_table *table, int write,
+int drop_caches_sysctl_handler(const struct ctl_table *table, int write,
 		void *buffer, size_t *length, loff_t *ppos)
 {
 	int ret;
diff --git a/fs/exec.c b/fs/exec.c
index 37f33212123c..a126e3d1cacb 100644
--- a/fs/exec.c
+++ b/fs/exec.c
@@ -2204,7 +2204,7 @@ COMPAT_SYSCALL_DEFINE5(execveat, int, fd,
 
 #ifdef CONFIG_SYSCTL
 
-static int proc_dointvec_minmax_coredump(struct ctl_table *table, int write,
+static int proc_dointvec_minmax_coredump(const struct ctl_table *table, int write,
 		void *buffer, size_t *lenp, loff_t *ppos)
 {
 	int error = proc_dointvec_minmax(table, write, buffer, lenp, ppos);
diff --git a/fs/file_table.c b/fs/file_table.c
index 4f03beed4737..ca7843dde56d 100644
--- a/fs/file_table.c
+++ b/fs/file_table.c
@@ -96,7 +96,7 @@ EXPORT_SYMBOL_GPL(get_max_files);
 /*
  * Handle nr_files sysctl
  */
-static int proc_nr_files(struct ctl_table *table, int write, void *buffer,
+static int proc_nr_files(const struct ctl_table *table, int write, void *buffer,
 			 size_t *lenp, loff_t *ppos)
 {
 	files_stat.nr_files = get_nr_files();
diff --git a/fs/fs-writeback.c b/fs/fs-writeback.c
index 92a5b8283528..b865a3fa52f3 100644
--- a/fs/fs-writeback.c
+++ b/fs/fs-writeback.c
@@ -2413,7 +2413,7 @@ static int __init start_dirtytime_writeback(void)
 }
 __initcall(start_dirtytime_writeback);
 
-int dirtytime_interval_handler(struct ctl_table *table, int write,
+int dirtytime_interval_handler(const struct ctl_table *table, int write,
 			       void *buffer, size_t *lenp, loff_t *ppos)
 {
 	int ret;
diff --git a/fs/inode.c b/fs/inode.c
index 470b57ef1cf5..86670941884b 100644
--- a/fs/inode.c
+++ b/fs/inode.c
@@ -107,7 +107,7 @@ long get_nr_dirty_inodes(void)
  */
 static struct inodes_stat_t inodes_stat;
 
-static int proc_nr_inodes(struct ctl_table *table, int write, void *buffer,
+static int proc_nr_inodes(const struct ctl_table *table, int write, void *buffer,
 			  size_t *lenp, loff_t *ppos)
 {
 	inodes_stat.nr_inodes = get_nr_inodes();
diff --git a/fs/pipe.c b/fs/pipe.c
index 50c8a8596b52..7dff2aa50a6d 100644
--- a/fs/pipe.c
+++ b/fs/pipe.c
@@ -1469,7 +1469,7 @@ static int do_proc_dopipe_max_size_conv(unsigned long *lvalp,
 	return 0;
 }
 
-static int proc_dopipe_max_size(struct ctl_table *table, int write,
+static int proc_dopipe_max_size(const struct ctl_table *table, int write,
 				void *buffer, size_t *lenp, loff_t *ppos)
 {
 	return do_proc_douintvec(table, write, buffer, lenp, ppos,
diff --git a/fs/quota/dquot.c b/fs/quota/dquot.c
index a2b256dac36e..7ae885e6d5d7 100644
--- a/fs/quota/dquot.c
+++ b/fs/quota/dquot.c
@@ -2913,7 +2913,7 @@ const struct quotactl_ops dquot_quotactl_sysfile_ops = {
 };
 EXPORT_SYMBOL(dquot_quotactl_sysfile_ops);
 
-static int do_proc_dqstats(struct ctl_table *table, int write,
+static int do_proc_dqstats(const struct ctl_table *table, int write,
 		     void *buffer, size_t *lenp, loff_t *ppos)
 {
 	unsigned int type = (unsigned long *)table->data - dqstats.stat;
diff --git a/fs/xfs/xfs_sysctl.c b/fs/xfs/xfs_sysctl.c
index a191f6560f98..c84df23b494d 100644
--- a/fs/xfs/xfs_sysctl.c
+++ b/fs/xfs/xfs_sysctl.c
@@ -11,7 +11,7 @@ static struct ctl_table_header *xfs_table_header;
 #ifdef CONFIG_PROC_FS
 STATIC int
 xfs_stats_clear_proc_handler(
-	struct ctl_table	*ctl,
+	const struct ctl_table	*ctl,
 	int			write,
 	void			*buffer,
 	size_t			*lenp,
@@ -31,7 +31,7 @@ xfs_stats_clear_proc_handler(
 
 STATIC int
 xfs_panic_mask_proc_handler(
-	struct ctl_table	*ctl,
+	const struct ctl_table	*ctl,
 	int			write,
 	void			*buffer,
 	size_t			*lenp,
@@ -52,7 +52,7 @@ xfs_panic_mask_proc_handler(
 
 STATIC int
 xfs_deprecated_dointvec_minmax(
-	struct ctl_table	*ctl,
+	const struct ctl_table	*ctl,
 	int			write,
 	void			*buffer,
 	size_t			*lenp,