sysctl: simplify the pty sysctl logic

Instead of having a bunch of ifdefs in sysctl.c move all of the pty sysctl
logic into drivers/char/pty.c

As well as cleaning up the logic this prevents sysctl_check_table from
complaining that the root table has a NULL data pointer on something with
generic methods.

Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

2 files changed, 23 insertions, 12 deletions

diff --git a/drivers/char/pty.c b/drivers/char/pty.c
index 73de77105fea..706ff34728f1 100644
--- a/drivers/char/pty.c
+++ b/drivers/char/pty.c
@@ -318,7 +318,7 @@ int pty_limit = NR_UNIX98_PTY_DEFAULT;
 static int pty_limit_min = 0;
 static int pty_limit_max = NR_UNIX98_PTY_MAX;
 
-ctl_table pty_table[] = {
+static struct ctl_table pty_table[] = {
         {
                 .ctl_name       = PTY_MAX,
                 .procname       = "max",
@@ -340,6 +340,27 @@ ctl_table pty_table[] = {
         }
 };
 
+static struct ctl_table pty_kern_table[] = {
+        {
+                .ctl_name       = KERN_PTY,
+                .procname       = "pty",
+                .mode           = 0555,
+                .child          = pty_table,
+        },
+        {}
+};
+
+static struct ctl_table pty_root_table[] = {
+        {
+                .ctl_name       = CTL_KERN,
+                .procname       = "kernel",
+                .mode           = 0555,
+                .child          = pty_kern_table,
+        },
+        {}
+};
+
+
 static int pty_unix98_ioctl(struct tty_struct *tty, struct file *file,
                             unsigned int cmd, unsigned long arg)
 {
@@ -404,6 +425,7 @@ static void __init unix98_pty_init(void)
                 panic("Couldn't register Unix98 pts driver");
 
         pty_table[1].data = &ptm_driver->refcount;
+        register_sysctl_table(pty_root_table);
 }
 #else
 static inline void unix98_pty_init(void) { }
diff --git a/kernel/sysctl.c b/kernel/sysctl.c
index bed6cdb3e47a..0278f52c4b04 100644
--- a/kernel/sysctl.c
+++ b/kernel/sysctl.c
@@ -163,9 +163,6 @@ static struct ctl_table fs_table[];
 static struct ctl_table debug_table[];
 static struct ctl_table dev_table[];
 extern struct ctl_table random_table[];
-#ifdef CONFIG_UNIX98_PTYS
-extern struct ctl_table pty_table[];
-#endif
 #ifdef CONFIG_INOTIFY_USER
 extern struct ctl_table inotify_table[];
 #endif
@@ -534,14 +531,6 @@ static struct ctl_table kern_table[] = {
                 .mode           = 0555,
                 .child          = random_table,
         },
-#ifdef CONFIG_UNIX98_PTYS
-        {
-                .ctl_name       = KERN_PTY,
-                .procname       = "pty",
-                .mode           = 0555,
-                .child          = pty_table,
-        },
-#endif
         {
                 .ctl_name       = KERN_OVERFLOWUID,
                 .procname       = "overflowuid",