From 593a27c4b212e2afdf772a1f8dcb894e91bda0fa Mon Sep 17 00:00:00 2001 From: Konstantin Khlebnikov Date: Thu, 5 Jan 2012 13:04:21 +0400 Subject: tty: cleanup prohibition of direct opening for unix98 pty master cleanup hack added in v2.6.27-3203-g15582d3 comment from that patch: : pty: If the administrator creates a device for a ptmx slave we should not error : : The open path for ptmx slaves is via the ptmx device. Opening them any : other way is not allowed. Vegard Nossum found that previously this was not : the case and mknod foo c 128 42; cat foo would produce nasty diagnostics : : Signed-off-by: Alan Cox : Signed-off-by: Linus Torvalds devpts_get_tty() returns non-null only for inodes on devpts, but there is no inodes for master-devices, /dev/ptmx (/dev/pts/ptmx) is the only way to open them. Thus we can completely forbid lookup for master-devices and eliminate that hack in tty_init_dev() because tty_open() will get EIO from tty_driver_lookup_tty(). Signed-off-by: Konstantin Khlebnikov Signed-off-by: Greg Kroah-Hartman --- drivers/tty/tty_io.c | 12 ++---------- 1 file changed, 2 insertions(+), 10 deletions(-) (limited to 'drivers/tty/tty_io.c') diff --git a/drivers/tty/tty_io.c b/drivers/tty/tty_io.c index e41b9bbc107d..fbcc14063804 100644 --- a/drivers/tty/tty_io.c +++ b/drivers/tty/tty_io.c @@ -1365,7 +1365,6 @@ static int tty_reopen(struct tty_struct *tty) * @driver: tty driver we are opening a device on * @idx: device index * @ret_tty: returned tty structure - * @first_ok: ok to open a new device (used by ptmx) * * Prepare a tty device. This may not be a "new" clean device but * could also be an active device. The pty drivers require special @@ -1385,18 +1384,11 @@ static int tty_reopen(struct tty_struct *tty) * relaxed for the (most common) case of reopening a tty. */ -struct tty_struct *tty_init_dev(struct tty_driver *driver, int idx, - int first_ok) +struct tty_struct *tty_init_dev(struct tty_driver *driver, int idx) { struct tty_struct *tty; int retval; - /* Check if pty master is being opened multiple times */ - if (driver->subtype == PTY_TYPE_MASTER && - (driver->flags & TTY_DRIVER_DEVPTS_MEM) && !first_ok) { - return ERR_PTR(-EIO); - } - /* * First time open is complex, especially for PTY devices. * This code guarantees that either everything succeeds and the @@ -1950,7 +1942,7 @@ retry_open: if (retval) tty = ERR_PTR(retval); } else - tty = tty_init_dev(driver, index, 0); + tty = tty_init_dev(driver, index); mutex_unlock(&tty_mutex); if (driver) -- cgit v1.2.3 From 66d450e84ec656ec4b774c41cd8d46b3e48d51df Mon Sep 17 00:00:00 2001 From: Jiri Slaby Date: Mon, 30 Jan 2012 21:14:28 +0100 Subject: TTY: provide tty_standard_install helper There are currently many cut&paste copies of what tty_driver_install_tty does when custom ->install method is not provided. Let's get rid of the copies and create a helper with this setup code. Signed-off-by: Jiri Slaby Cc: Havard Skinnemoen Acked-by: Alan Cox Signed-off-by: Greg Kroah-Hartman --- drivers/tty/tty_io.c | 30 +++++++++++++++--------------- include/linux/tty.h | 2 ++ 2 files changed, 17 insertions(+), 15 deletions(-) (limited to 'drivers/tty/tty_io.c') diff --git a/drivers/tty/tty_io.c b/drivers/tty/tty_io.c index fbcc14063804..44736f9e61d7 100644 --- a/drivers/tty/tty_io.c +++ b/drivers/tty/tty_io.c @@ -1271,6 +1271,19 @@ int tty_init_termios(struct tty_struct *tty) } EXPORT_SYMBOL_GPL(tty_init_termios); +int tty_standard_install(struct tty_driver *driver, struct tty_struct *tty) +{ + int ret = tty_init_termios(tty); + if (ret) + return ret; + + tty_driver_kref_get(driver); + tty->count++; + driver->ttys[tty->index] = tty; + return 0; +} +EXPORT_SYMBOL_GPL(tty_standard_install); + /** * tty_driver_install_tty() - install a tty entry in the driver * @driver: the driver for the tty @@ -1286,21 +1299,8 @@ EXPORT_SYMBOL_GPL(tty_init_termios); static int tty_driver_install_tty(struct tty_driver *driver, struct tty_struct *tty) { - int idx = tty->index; - int ret; - - if (driver->ops->install) { - ret = driver->ops->install(driver, tty); - return ret; - } - - if (tty_init_termios(tty) == 0) { - tty_driver_kref_get(driver); - tty->count++; - driver->ttys[idx] = tty; - return 0; - } - return -ENOMEM; + return driver->ops->install ? driver->ops->install(driver, tty) : + tty_standard_install(driver, tty); } /** diff --git a/include/linux/tty.h b/include/linux/tty.h index d40774188203..a91ff403b3bf 100644 --- a/include/linux/tty.h +++ b/include/linux/tty.h @@ -484,6 +484,8 @@ extern void deinitialize_tty_struct(struct tty_struct *tty); extern struct tty_struct *tty_init_dev(struct tty_driver *driver, int idx); extern int tty_release(struct inode *inode, struct file *filp); extern int tty_init_termios(struct tty_struct *tty); +extern int tty_standard_install(struct tty_driver *driver, + struct tty_struct *tty); extern struct tty_struct *tty_pair_get_tty(struct tty_struct *tty); extern struct tty_struct *tty_pair_get_pty(struct tty_struct *tty); -- cgit v1.2.3 From d3bda5298aad98c7a27678bdd0dd9d008ab9e685 Mon Sep 17 00:00:00 2001 From: Jiri Slaby Date: Mon, 30 Jan 2012 21:14:32 +0100 Subject: TTY: get rid of BTM around devpts_* devpts operations are protected by inode mutexes and dentry refcounting. There is no need to hold BTM. Signed-off-by: Jiri Slaby Signed-off-by: Greg Kroah-Hartman --- drivers/tty/pty.c | 6 ++---- drivers/tty/tty_io.c | 2 +- 2 files changed, 3 insertions(+), 5 deletions(-) (limited to 'drivers/tty/tty_io.c') diff --git a/drivers/tty/pty.c b/drivers/tty/pty.c index ddec9f3c3396..39afd045f8ef 100644 --- a/drivers/tty/pty.c +++ b/drivers/tty/pty.c @@ -54,8 +54,8 @@ static void pty_close(struct tty_struct *tty, struct file *filp) wake_up_interruptible(&tty->link->write_wait); if (tty->driver->subtype == PTY_TYPE_MASTER) { set_bit(TTY_OTHER_CLOSED, &tty->flags); - devpts_pty_kill(tty->link); tty_unlock(); + devpts_pty_kill(tty->link); tty_vhangup(tty->link); tty_lock(); } @@ -613,9 +613,7 @@ static int ptmx_open(struct inode *inode, struct file *filp) return retval; /* find a device that is not in use. */ - tty_lock(); index = devpts_new_index(inode); - tty_unlock(); if (index < 0) { retval = index; goto err_file; @@ -650,8 +648,8 @@ err_release: tty_release(inode, filp); return retval; out: - devpts_kill_index(inode, index); tty_unlock(); + devpts_kill_index(inode, index); err_file: tty_free_file(filp); return retval; diff --git a/drivers/tty/tty_io.c b/drivers/tty/tty_io.c index 44736f9e61d7..ea7ebe22a16c 100644 --- a/drivers/tty/tty_io.c +++ b/drivers/tty/tty_io.c @@ -1789,11 +1789,11 @@ int tty_release(struct inode *inode, struct file *filp) * the slots and preserving the termios structure. */ release_tty(tty, idx); + tty_unlock(); /* Make this pty number available for reallocation */ if (devpts) devpts_kill_index(inode, idx); - tty_unlock(); return 0; } -- cgit v1.2.3 From 0ef1698e4d6282a1665207c40b115ec78fceda9b Mon Sep 17 00:00:00 2001 From: Greg Kroah-Hartman Date: Fri, 24 Feb 2012 13:55:54 -0800 Subject: Revert "TTY: get rid of BTM around devpts_*" This reverts commit d3bda5298aad98c7a27678bdd0dd9d008ab9e685. Sasha reported that this causes problems, so revert it. Cc: Sasha Levin Cc: Jiri Slaby Signed-off-by: Greg Kroah-Hartman --- drivers/tty/pty.c | 6 ++++-- drivers/tty/tty_io.c | 2 +- 2 files changed, 5 insertions(+), 3 deletions(-) (limited to 'drivers/tty/tty_io.c') diff --git a/drivers/tty/pty.c b/drivers/tty/pty.c index 39afd045f8ef..ddec9f3c3396 100644 --- a/drivers/tty/pty.c +++ b/drivers/tty/pty.c @@ -54,8 +54,8 @@ static void pty_close(struct tty_struct *tty, struct file *filp) wake_up_interruptible(&tty->link->write_wait); if (tty->driver->subtype == PTY_TYPE_MASTER) { set_bit(TTY_OTHER_CLOSED, &tty->flags); - tty_unlock(); devpts_pty_kill(tty->link); + tty_unlock(); tty_vhangup(tty->link); tty_lock(); } @@ -613,7 +613,9 @@ static int ptmx_open(struct inode *inode, struct file *filp) return retval; /* find a device that is not in use. */ + tty_lock(); index = devpts_new_index(inode); + tty_unlock(); if (index < 0) { retval = index; goto err_file; @@ -648,8 +650,8 @@ err_release: tty_release(inode, filp); return retval; out: - tty_unlock(); devpts_kill_index(inode, index); + tty_unlock(); err_file: tty_free_file(filp); return retval; diff --git a/drivers/tty/tty_io.c b/drivers/tty/tty_io.c index ea7ebe22a16c..44736f9e61d7 100644 --- a/drivers/tty/tty_io.c +++ b/drivers/tty/tty_io.c @@ -1789,11 +1789,11 @@ int tty_release(struct inode *inode, struct file *filp) * the slots and preserving the termios structure. */ release_tty(tty, idx); - tty_unlock(); /* Make this pty number available for reallocation */ if (devpts) devpts_kill_index(inode, idx); + tty_unlock(); return 0; } -- cgit v1.2.3 From a8fbc974c347a798fd0c6f0bffe7bf46b8c6dfb6 Mon Sep 17 00:00:00 2001 From: Jiri Slaby Date: Mon, 5 Mar 2012 14:51:49 +0100 Subject: TTY: tty_io, remove buffer re-assignments TTY buffer head and tail are initialized in tty_buffer_init. No need to do it once again in initialize_tty_struct where tty_buffer_init is called. Signed-off-by: Jiri Slaby Signed-off-by: Greg Kroah-Hartman --- drivers/tty/tty_io.c | 1 - 1 file changed, 1 deletion(-) (limited to 'drivers/tty/tty_io.c') diff --git a/drivers/tty/tty_io.c b/drivers/tty/tty_io.c index 44736f9e61d7..f105ce5c8e6e 100644 --- a/drivers/tty/tty_io.c +++ b/drivers/tty/tty_io.c @@ -2933,7 +2933,6 @@ void initialize_tty_struct(struct tty_struct *tty, tty->session = NULL; tty->pgrp = NULL; tty->overrun_time = jiffies; - tty->buf.head = tty->buf.tail = NULL; tty_buffer_init(tty); mutex_init(&tty->termios_mutex); mutex_init(&tty->ldisc_mutex); -- cgit v1.2.3 From 1a54a76d5171f3ffd89eb69f6f38d535724e3d05 Mon Sep 17 00:00:00 2001 From: Jiri Slaby Date: Mon, 5 Mar 2012 14:51:50 +0100 Subject: TTY: let alloc_tty_driver deduce the owner automatically Like the rest of the kernel, make a stub from alloc_tty_driver which calls __alloc_tty_driver with proper owner. This will save us one more assignment on the driver side. Also this fixes some drivers which didn't set the owner. This allowed user to remove the module from the system even though a tty from the driver is still open. Signed-off-by: Jiri Slaby Signed-off-by: Greg Kroah-Hartman --- drivers/tty/tty_io.c | 5 +++-- include/linux/tty_driver.h | 5 ++++- 2 files changed, 7 insertions(+), 3 deletions(-) (limited to 'drivers/tty/tty_io.c') diff --git a/drivers/tty/tty_io.c b/drivers/tty/tty_io.c index f105ce5c8e6e..bd95cea3173b 100644 --- a/drivers/tty/tty_io.c +++ b/drivers/tty/tty_io.c @@ -3049,7 +3049,7 @@ void tty_unregister_device(struct tty_driver *driver, unsigned index) } EXPORT_SYMBOL(tty_unregister_device); -struct tty_driver *alloc_tty_driver(int lines) +struct tty_driver *__alloc_tty_driver(int lines, struct module *owner) { struct tty_driver *driver; @@ -3058,11 +3058,12 @@ struct tty_driver *alloc_tty_driver(int lines) kref_init(&driver->kref); driver->magic = TTY_DRIVER_MAGIC; driver->num = lines; + driver->owner = owner; /* later we'll move allocation of tables here */ } return driver; } -EXPORT_SYMBOL(alloc_tty_driver); +EXPORT_SYMBOL(__alloc_tty_driver); static void destruct_tty_driver(struct kref *kref) { diff --git a/include/linux/tty_driver.h b/include/linux/tty_driver.h index 5cf685086dd3..6e65493a5e6c 100644 --- a/include/linux/tty_driver.h +++ b/include/linux/tty_driver.h @@ -234,6 +234,7 @@ * if provided (otherwise EINVAL will be returned). */ +#include #include #include #include @@ -324,7 +325,7 @@ struct tty_driver { extern struct list_head tty_drivers; -extern struct tty_driver *alloc_tty_driver(int lines); +extern struct tty_driver *__alloc_tty_driver(int lines, struct module *owner); extern void put_tty_driver(struct tty_driver *driver); extern void tty_set_operations(struct tty_driver *driver, const struct tty_operations *op); @@ -332,6 +333,8 @@ extern struct tty_driver *tty_find_polling_driver(char *name, int *line); extern void tty_driver_kref_put(struct tty_driver *driver); +#define alloc_tty_driver(lines) __alloc_tty_driver(lines, THIS_MODULE) + static inline struct tty_driver *tty_driver_kref_get(struct tty_driver *d) { kref_get(&d->kref); -- cgit v1.2.3 From d4834267e81c8f08685e6ee55751551fa60f66e3 Mon Sep 17 00:00:00 2001 From: Jiri Slaby Date: Mon, 5 Mar 2012 14:51:53 +0100 Subject: TTY: simplify tty_driver_lookup_tty a bit Remove the useless local variable and return the value itself. Signed-off-by: Jiri Slaby Signed-off-by: Greg Kroah-Hartman --- drivers/tty/tty_io.c | 5 +---- 1 file changed, 1 insertion(+), 4 deletions(-) (limited to 'drivers/tty/tty_io.c') diff --git a/drivers/tty/tty_io.c b/drivers/tty/tty_io.c index bd95cea3173b..d0d3d1f94926 100644 --- a/drivers/tty/tty_io.c +++ b/drivers/tty/tty_io.c @@ -1230,13 +1230,10 @@ static void tty_line_name(struct tty_driver *driver, int index, char *p) static struct tty_struct *tty_driver_lookup_tty(struct tty_driver *driver, struct inode *inode, int idx) { - struct tty_struct *tty; - if (driver->ops->lookup) return driver->ops->lookup(driver, inode, idx); - tty = driver->ttys[idx]; - return tty; + return driver->ttys[idx]; } /** -- cgit v1.2.3 From ecd166507f4218c9988d005feb04b7215f9df321 Mon Sep 17 00:00:00 2001 From: Jiri Slaby Date: Mon, 5 Mar 2012 14:51:54 +0100 Subject: TTY: remove tty driver re-set from tty_reopen This is from tty_reopen: struct tty_driver *driver = tty->driver; ... tty->driver = driver; and it doesn't make sense at all. The driver is intended to be set in initialize_tty_struct from tty_init_dev (initial open). So this set in tty_reopen is not needed. Signed-off-by: Jiri Slaby Signed-off-by: Greg Kroah-Hartman --- drivers/tty/tty_io.c | 1 - 1 file changed, 1 deletion(-) (limited to 'drivers/tty/tty_io.c') diff --git a/drivers/tty/tty_io.c b/drivers/tty/tty_io.c index d0d3d1f94926..dd8a938510ca 100644 --- a/drivers/tty/tty_io.c +++ b/drivers/tty/tty_io.c @@ -1348,7 +1348,6 @@ static int tty_reopen(struct tty_struct *tty) tty->link->count++; } tty->count++; - tty->driver = driver; /* N.B. why do this every time?? */ mutex_lock(&tty->ldisc_mutex); WARN_ON(!test_bit(TTY_LDISC, &tty->flags)); -- cgit v1.2.3