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Commit d2fde28c authored by Linus Torvalds's avatar Linus Torvalds
Browse files

Merge branch 'tty-updates' from Alan 

* tty-updates: (75 commits)
  serial_8250: support for Sealevel Systems Model 7803 COMM+8
  hso maintainers update patch
  hso modem detect fix patch against Alan Cox'es tty tree
  tty: Fix an ircomm warning and note another bug
  drivers/char/cyclades.c: cy_pci_probe: fix error path
  Serial: UART driver changes for Cavium OCTEON.
  Serial: Allow port type to be specified when calling serial8250_register_port.
  8250: Serial driver changes to support future Cavium OCTEON serial patches.
  8250: Don't clobber spinlocks.
  fix for tty-serial-move-port
  tty: We want the port object to be persistent
  __FUNCTION__ is gcc-specific, use __func__
  serial: RS485 ioctl structure uses __u32 include linux/types.h
  tty: Drop the lock_kernel in the private ioctl hook
  synclink_cs: Convert to tty_port
  tty: use port methods for the rocket driver
  tty: kref the rocket driver
  tty: make rocketport use standard port->flags
  tty: Redo the rocket driver locking
  tty: Make epca use the port helpers
  ...
parents 609e5b71 e65f0f82

Documentation/filesystems/devpts.txt

0 → 100644
+132 −0
Original line number Diff line number Diff line 


To support containers, we now allow multiple instances of devpts filesystem,

such that indices of ptys allocated in one instance are independent of indices

allocated in other instances of devpts.



To preserve backward compatibility, this support for multiple instances is

enabled only if:



	- CONFIG_DEVPTS_MULTIPLE_INSTANCES=y, and

	- '-o newinstance' mount option is specified while mounting devpts



IOW, devpts now supports both single-instance and multi-instance semantics.



If CONFIG_DEVPTS_MULTIPLE_INSTANCES=n, there is no change in behavior and

this referred to as the "legacy" mode. In this mode, the new mount options

(-o newinstance and -o ptmxmode) will be ignored with a 'bogus option' message

on console.



If CONFIG_DEVPTS_MULTIPLE_INSTANCES=y and devpts is mounted without the

'newinstance' option (as in current start-up scripts) the new mount binds

to the initial kernel mount of devpts. This mode is referred to as the

'single-instance' mode and the current, single-instance semantics are

preserved, i.e PTYs are common across the system.



The only difference between this single-instance mode and the legacy mode

is the presence of new, '/dev/pts/ptmx' node with permissions 0000, which

can safely be ignored.



If CONFIG_DEVPTS_MULTIPLE_INSTANCES=y and 'newinstance' option is specified,

the mount is considered to be in the multi-instance mode and a new instance

of the devpts fs is created. Any ptys created in this instance are independent

of ptys in other instances of devpts. Like in the single-instance mode, the

/dev/pts/ptmx node is present. To effectively use the multi-instance mode,

open of /dev/ptmx must be a redirected to '/dev/pts/ptmx' using a symlink or

bind-mount.



Eg: A container startup script could do the following:



	$ chmod 0666 /dev/pts/ptmx

	$ rm /dev/ptmx

	$ ln -s pts/ptmx /dev/ptmx

	$ ns_exec -cm /bin/bash



	# We are now in new container



	$ umount /dev/pts

	$ mount -t devpts -o newinstance lxcpts /dev/pts

	$ sshd -p 1234



where 'ns_exec -cm /bin/bash' calls clone() with CLONE_NEWNS flag and execs

/bin/bash in the child process.  A pty created by the sshd is not visible in

the original mount of /dev/pts.



User-space changes

------------------



In multi-instance mode (i.e '-o newinstance' mount option is specified at least

once), following user-space issues should be noted.



1. If -o newinstance mount option is never used, /dev/pts/ptmx can be ignored

   and no change is needed to system-startup scripts.



2. To effectively use multi-instance mode (i.e -o newinstance is specified)

   administrators or startup scripts should "redirect" open of /dev/ptmx to

   /dev/pts/ptmx using either a bind mount or symlink.



	$ mount -t devpts -o newinstance devpts /dev/pts



   followed by either



	$ rm /dev/ptmx

	$ ln -s pts/ptmx /dev/ptmx

	$ chmod 666 /dev/pts/ptmx

   or

	$ mount -o bind /dev/pts/ptmx /dev/ptmx



3. The '/dev/ptmx -> pts/ptmx' symlink is the preferred method since it

   enables better error-reporting and treats both single-instance and

   multi-instance mounts similarly.



   But this method requires that system-startup scripts set the mode of

   /dev/pts/ptmx correctly (default mode is 0000). The scripts can set the

   mode by, either



   	- adding ptmxmode mount option to devpts entry in /etc/fstab, or

	- using 'chmod 0666 /dev/pts/ptmx'



4. If multi-instance mode mount is needed for containers, but the system

   startup scripts have not yet been updated, container-startup scripts

   should bind mount /dev/ptmx to /dev/pts/ptmx to avoid breaking single-

   instance mounts.



   Or, in general, container-startup scripts should use:



	mount -t devpts -o newinstance -o ptmxmode=0666 devpts /dev/pts

	if [ ! -L /dev/ptmx ]; then

		mount -o bind /dev/pts/ptmx /dev/ptmx

	fi



   When all devpts mounts are multi-instance, /dev/ptmx can permanently be

   a symlink to pts/ptmx and the bind mount can be ignored.



5. A multi-instance mount that is not accompanied by the /dev/ptmx to

   /dev/pts/ptmx redirection would result in an unusable/unreachable pty.



	mount -t devpts -o newinstance lxcpts /dev/pts



   immediately followed by:



	open("/dev/ptmx")



    would create a pty, say /dev/pts/7, in the initial kernel mount.

    But /dev/pts/7 would be invisible in the new mount.



6. The permissions for /dev/pts/ptmx node should be specified when mounting

   /dev/pts, using the '-o ptmxmode=%o' mount option (default is 0000).



	mount -t devpts -o newinstance -o ptmxmode=0644 devpts /dev/pts



   The permissions can be later be changed as usual with 'chmod'.



	chmod 666 /dev/pts/ptmx



7. A mount of devpts without the 'newinstance' option results in binding to

   initial kernel mount.  This behavior while preserving legacy semantics,

   does not provide strict isolation in a container environment. i.e by

   mounting devpts without the 'newinstance' option, a container could

   get visibility into the 'host' or root container's devpts.

   

   To workaround this and have strict isolation, all mounts of devpts,

   including the mount in the root container, should use the newinstance

   option.

MAINTAINERS

+6 −0
Original line number Diff line number Diff line
@@ -2049,6 +2049,12 @@ M: mikulas@artax.karlin.mff.cuni.cz 
W:	http://artax.karlin.mff.cuni.cz/~mikulas/vyplody/hpfs/index-e.cgi

S:	Maintained



HSO	3G Modem Driver (hso.c)

P:	Denis Joseph Barrow

M:	d.barow@option.com

W:	http://www.pharscape.org

S:	Maintained



HTCPEN TOUCHSCREEN DRIVER

P:	Pau Oliva Fora

M:	pof@eslack.org

drivers/char/Kconfig

+12 −1
Original line number Diff line number Diff line
@@ -190,7 +190,7 @@ config DIGIEPCA 


config ESPSERIAL

	tristate "Hayes ESP serial port support"

	depends on SERIAL_NONSTANDARD && ISA && ISA_DMA_API

	depends on SERIAL_NONSTANDARD && ISA && ISA_DMA_API && BROKEN

	help

	  This is a driver which supports Hayes ESP serial ports.  Both single

	  port cards and multiport cards are supported.  Make sure to read
@@ -443,6 +443,17 @@ config UNIX98_PTYS 
	  All modern Linux systems use the Unix98 ptys.  Say Y unless

	  you're on an embedded system and want to conserve memory.



config DEVPTS_MULTIPLE_INSTANCES

	bool "Support multiple instances of devpts"

	depends on UNIX98_PTYS

	default n

	---help---

	  Enable support for multiple instances of devpts filesystem.

	  If you want to have isolated PTY namespaces (eg: in containers),

	  say Y here.  Otherwise, say N. If enabled, each mount of devpts

	  filesystem with the '-o newinstance' option will create an

	  independent PTY namespace.



config LEGACY_PTYS

	bool "Legacy (BSD) PTY support"

	default y

drivers/char/amiserial.c

+17 −17
Original line number Diff line number Diff line
@@ -170,7 +170,7 @@ static __inline__ void rtsdtr_ctrl(int bits) 
 */

static void rs_stop(struct tty_struct *tty)

{

	struct async_struct *info = (struct async_struct *)tty->driver_data;

	struct async_struct *info = tty->driver_data;

	unsigned long flags;



	if (serial_paranoia_check(info, tty->name, "rs_stop"))
@@ -190,7 +190,7 @@ static void rs_stop(struct tty_struct *tty) 


static void rs_start(struct tty_struct *tty)

{

	struct async_struct *info = (struct async_struct *)tty->driver_data;

	struct async_struct *info = tty->driver_data;

	unsigned long flags;



	if (serial_paranoia_check(info, tty->name, "rs_start"))
@@ -861,7 +861,7 @@ static int rs_put_char(struct tty_struct *tty, unsigned char ch) 


static void rs_flush_chars(struct tty_struct *tty)

{

	struct async_struct *info = (struct async_struct *)tty->driver_data;

	struct async_struct *info = tty->driver_data;

	unsigned long flags;



	if (serial_paranoia_check(info, tty->name, "rs_flush_chars"))
@@ -934,7 +934,7 @@ static int rs_write(struct tty_struct * tty, const unsigned char *buf, int count 


static int rs_write_room(struct tty_struct *tty)

{

	struct async_struct *info = (struct async_struct *)tty->driver_data;

	struct async_struct *info = tty->driver_data;



	if (serial_paranoia_check(info, tty->name, "rs_write_room"))

		return 0;
@@ -943,7 +943,7 @@ static int rs_write_room(struct tty_struct *tty) 


static int rs_chars_in_buffer(struct tty_struct *tty)

{

	struct async_struct *info = (struct async_struct *)tty->driver_data;

	struct async_struct *info = tty->driver_data;



	if (serial_paranoia_check(info, tty->name, "rs_chars_in_buffer"))

		return 0;
@@ -952,7 +952,7 @@ static int rs_chars_in_buffer(struct tty_struct *tty) 


static void rs_flush_buffer(struct tty_struct *tty)

{

	struct async_struct *info = (struct async_struct *)tty->driver_data;

	struct async_struct *info = tty->driver_data;

	unsigned long flags;



	if (serial_paranoia_check(info, tty->name, "rs_flush_buffer"))
@@ -969,7 +969,7 @@ static void rs_flush_buffer(struct tty_struct *tty) 
 */

static void rs_send_xchar(struct tty_struct *tty, char ch)

{

	struct async_struct *info = (struct async_struct *)tty->driver_data;

	struct async_struct *info = tty->driver_data;

        unsigned long flags;



	if (serial_paranoia_check(info, tty->name, "rs_send_char"))
@@ -1004,7 +1004,7 @@ static void rs_send_xchar(struct tty_struct *tty, char ch) 
 */

static void rs_throttle(struct tty_struct * tty)

{

	struct async_struct *info = (struct async_struct *)tty->driver_data;

	struct async_struct *info = tty->driver_data;

	unsigned long flags;

#ifdef SERIAL_DEBUG_THROTTLE

	char	buf[64];
@@ -1029,7 +1029,7 @@ static void rs_throttle(struct tty_struct * tty) 


static void rs_unthrottle(struct tty_struct * tty)

{

	struct async_struct *info = (struct async_struct *)tty->driver_data;

	struct async_struct *info = tty->driver_data;

	unsigned long flags;

#ifdef SERIAL_DEBUG_THROTTLE

	char	buf[64];
@@ -1194,7 +1194,7 @@ static int get_lsr_info(struct async_struct * info, unsigned int __user *value) 


static int rs_tiocmget(struct tty_struct *tty, struct file *file)

{

	struct async_struct * info = (struct async_struct *)tty->driver_data;

	struct async_struct * info = tty->driver_data;

	unsigned char control, status;

	unsigned long flags;
@@ -1217,7 +1217,7 @@ static int rs_tiocmget(struct tty_struct *tty, struct file *file) 
static int rs_tiocmset(struct tty_struct *tty, struct file *file,

		       unsigned int set, unsigned int clear)

{

	struct async_struct * info = (struct async_struct *)tty->driver_data;

	struct async_struct * info = tty->driver_data;

	unsigned long flags;



	if (serial_paranoia_check(info, tty->name, "rs_ioctl"))
@@ -1244,7 +1244,7 @@ static int rs_tiocmset(struct tty_struct *tty, struct file *file, 
 */

static int rs_break(struct tty_struct *tty, int break_state)

{

	struct async_struct * info = (struct async_struct *)tty->driver_data;

	struct async_struct * info = tty->driver_data;

	unsigned long flags;



	if (serial_paranoia_check(info, tty->name, "rs_break"))
@@ -1264,7 +1264,7 @@ static int rs_break(struct tty_struct *tty, int break_state) 
static int rs_ioctl(struct tty_struct *tty, struct file * file,

		    unsigned int cmd, unsigned long arg)

{

	struct async_struct * info = (struct async_struct *)tty->driver_data;

	struct async_struct * info = tty->driver_data;

	struct async_icount cprev, cnow;	/* kernel counter temps */

	struct serial_icounter_struct icount;

	void __user *argp = (void __user *)arg;
@@ -1368,7 +1368,7 @@ static int rs_ioctl(struct tty_struct *tty, struct file * file, 


static void rs_set_termios(struct tty_struct *tty, struct ktermios *old_termios)

{

	struct async_struct *info = (struct async_struct *)tty->driver_data;

	struct async_struct *info = tty->driver_data;

	unsigned long flags;

	unsigned int cflag = tty->termios->c_cflag;
@@ -1428,7 +1428,7 @@ static void rs_set_termios(struct tty_struct *tty, struct ktermios *old_termios) 
 */

static void rs_close(struct tty_struct *tty, struct file * filp)

{

	struct async_struct * info = (struct async_struct *)tty->driver_data;

	struct async_struct * info = tty->driver_data;

	struct serial_state *state;

	unsigned long flags;
@@ -1523,7 +1523,7 @@ static void rs_close(struct tty_struct *tty, struct file * filp) 
 */

static void rs_wait_until_sent(struct tty_struct *tty, int timeout)

{

	struct async_struct * info = (struct async_struct *)tty->driver_data;

	struct async_struct * info = tty->driver_data;

	unsigned long orig_jiffies, char_time;

	int lsr;
@@ -1587,7 +1587,7 @@ static void rs_wait_until_sent(struct tty_struct *tty, int timeout) 
 */

static void rs_hangup(struct tty_struct *tty)

{

	struct async_struct * info = (struct async_struct *)tty->driver_data;

	struct async_struct * info = tty->driver_data;

	struct serial_state *state = info->state;



	if (serial_paranoia_check(info, tty->name, "rs_hangup"))

drivers/char/cyclades.c

+1 −1
Original line number Diff line number Diff line
@@ -5010,7 +5010,7 @@ static int __devinit cy_pci_probe(struct pci_dev *pdev, 
		if (nchan == 0) {

			dev_err(&pdev->dev, "Cyclom-Y PCI host card with no "

					"Serial-Modules\n");

			return -EIO;

			goto err_unmap;

		}

	} else if (device_id == PCI_DEVICE_ID_CYCLOM_Z_Hi) {

		struct RUNTIME_9060 __iomem *ctl_addr;