tty: move pty count limiting into devpts

Let's move this stuff to the better place, where we can account pty right in
tty-indexes managing code.

Signed-off-by: Konstantin Khlebnikov <khlebnikov@openvz.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
This commit is contained in:
Konstantin Khlebnikov 2012-01-05 13:06:02 +04:00 committed by Greg Kroah-Hartman
parent 593a27c4b2
commit a4834c102f
2 changed files with 52 additions and 52 deletions

View File

@ -21,7 +21,6 @@
#include <linux/major.h>
#include <linux/mm.h>
#include <linux/init.h>
#include <linux/sysctl.h>
#include <linux/device.h>
#include <linux/uaccess.h>
#include <linux/bitops.h>
@ -439,55 +438,9 @@ static inline void legacy_pty_init(void) { }
/* Unix98 devices */
#ifdef CONFIG_UNIX98_PTYS
/*
* sysctl support for setting limits on the number of Unix98 ptys allocated.
* Otherwise one can eat up all kernel memory by opening /dev/ptmx repeatedly.
*/
int pty_limit = NR_UNIX98_PTY_DEFAULT;
static int pty_limit_min;
static int pty_limit_max = NR_UNIX98_PTY_MAX;
static int pty_count;
static struct cdev ptmx_cdev;
static struct ctl_table pty_table[] = {
{
.procname = "max",
.maxlen = sizeof(int),
.mode = 0644,
.data = &pty_limit,
.proc_handler = proc_dointvec_minmax,
.extra1 = &pty_limit_min,
.extra2 = &pty_limit_max,
}, {
.procname = "nr",
.maxlen = sizeof(int),
.mode = 0444,
.data = &pty_count,
.proc_handler = proc_dointvec,
},
{}
};
static struct ctl_table pty_kern_table[] = {
{
.procname = "pty",
.mode = 0555,
.child = pty_table,
},
{}
};
static struct ctl_table pty_root_table[] = {
{
.procname = "kernel",
.mode = 0555,
.child = pty_kern_table,
},
{}
};
static int pty_unix98_ioctl(struct tty_struct *tty,
unsigned int cmd, unsigned long arg)
{
@ -587,7 +540,6 @@ static int pty_unix98_install(struct tty_driver *driver, struct tty_struct *tty)
*/
tty_driver_kref_get(driver);
tty->count++;
pty_count++;
return 0;
err_free_mem:
deinitialize_tty_struct(o_tty);
@ -601,7 +553,6 @@ err_free_tty:
static void ptm_unix98_remove(struct tty_driver *driver, struct tty_struct *tty)
{
pty_count--;
}
static void pts_unix98_remove(struct tty_driver *driver, struct tty_struct *tty)
@ -760,8 +711,6 @@ static void __init unix98_pty_init(void)
if (tty_register_driver(pts_driver))
panic("Couldn't register Unix98 pts driver");
register_sysctl_table(pty_root_table);
/* Now create the /dev/ptmx special device */
tty_default_fops(&ptmx_fops);
ptmx_fops.open = ptmx_open;

View File

@ -36,7 +36,52 @@
#define DEVPTS_DEFAULT_PTMX_MODE 0000
#define PTMX_MINOR 2
extern int pty_limit; /* Config limit on Unix98 ptys */
/*
* sysctl support for setting limits on the number of Unix98 ptys allocated.
* Otherwise one can eat up all kernel memory by opening /dev/ptmx repeatedly.
*/
static int pty_limit = NR_UNIX98_PTY_DEFAULT;
static int pty_limit_min;
static int pty_limit_max = NR_UNIX98_PTY_MAX;
static int pty_count;
static struct ctl_table pty_table[] = {
{
.procname = "max",
.maxlen = sizeof(int),
.mode = 0644,
.data = &pty_limit,
.proc_handler = proc_dointvec_minmax,
.extra1 = &pty_limit_min,
.extra2 = &pty_limit_max,
}, {
.procname = "nr",
.maxlen = sizeof(int),
.mode = 0444,
.data = &pty_count,
.proc_handler = proc_dointvec,
},
{}
};
static struct ctl_table pty_kern_table[] = {
{
.procname = "pty",
.mode = 0555,
.child = pty_table,
},
{}
};
static struct ctl_table pty_root_table[] = {
{
.procname = "kernel",
.mode = 0555,
.child = pty_kern_table,
},
{}
};
static DEFINE_MUTEX(allocated_ptys_lock);
static struct vfsmount *devpts_mnt;
@ -451,6 +496,7 @@ retry:
mutex_unlock(&allocated_ptys_lock);
return -EIO;
}
pty_count++;
mutex_unlock(&allocated_ptys_lock);
return index;
}
@ -462,6 +508,7 @@ void devpts_kill_index(struct inode *ptmx_inode, int idx)
mutex_lock(&allocated_ptys_lock);
ida_remove(&fsi->allocated_ptys, idx);
pty_count--;
mutex_unlock(&allocated_ptys_lock);
}
@ -558,11 +605,15 @@ void devpts_pty_kill(struct tty_struct *tty)
static int __init init_devpts_fs(void)
{
int err = register_filesystem(&devpts_fs_type);
struct ctl_table_header *table;
if (!err) {
table = register_sysctl_table(pty_root_table);
devpts_mnt = kern_mount(&devpts_fs_type);
if (IS_ERR(devpts_mnt)) {
err = PTR_ERR(devpts_mnt);
unregister_filesystem(&devpts_fs_type);
unregister_sysctl_table(table);
}
}
return err;