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authorAndré Fabian Silva Delgado <emulatorman@parabola.nu>2015-12-15 14:52:16 -0300
committerAndré Fabian Silva Delgado <emulatorman@parabola.nu>2015-12-15 14:52:16 -0300
commit8d91c1e411f55d7ea91b1183a2e9f8088fb4d5be (patch)
treee9891aa6c295060d065adffd610c4f49ecf884f3 /drivers/tty/tty_io.c
parenta71852147516bc1cb5b0b3cbd13639bfd4022dc8 (diff)
Linux-libre 4.3.2-gnu
Diffstat (limited to 'drivers/tty/tty_io.c')
-rw-r--r--drivers/tty/tty_io.c117
1 files changed, 63 insertions, 54 deletions
diff --git a/drivers/tty/tty_io.c b/drivers/tty/tty_io.c
index 774df354a..f435977de 100644
--- a/drivers/tty/tty_io.c
+++ b/drivers/tty/tty_io.c
@@ -106,6 +106,11 @@
#include <linux/nsproxy.h>
#undef TTY_DEBUG_HANGUP
+#ifdef TTY_DEBUG_HANGUP
+# define tty_debug_hangup(tty, f, args...) tty_debug(tty, f, ##args)
+#else
+# define tty_debug_hangup(tty, f, args...) do { } while (0)
+#endif
#define TTY_PARANOIA_CHECK 1
#define CHECK_TTY_COUNT 1
@@ -388,33 +393,40 @@ EXPORT_SYMBOL_GPL(tty_find_polling_driver);
int tty_check_change(struct tty_struct *tty)
{
unsigned long flags;
+ struct pid *pgrp;
int ret = 0;
if (current->signal->tty != tty)
return 0;
+ rcu_read_lock();
+ pgrp = task_pgrp(current);
+
spin_lock_irqsave(&tty->ctrl_lock, flags);
if (!tty->pgrp) {
printk(KERN_WARNING "tty_check_change: tty->pgrp == NULL!\n");
goto out_unlock;
}
- if (task_pgrp(current) == tty->pgrp)
+ if (pgrp == tty->pgrp)
goto out_unlock;
spin_unlock_irqrestore(&tty->ctrl_lock, flags);
+
if (is_ignored(SIGTTOU))
- goto out;
+ goto out_rcuunlock;
if (is_current_pgrp_orphaned()) {
ret = -EIO;
- goto out;
+ goto out_rcuunlock;
}
- kill_pgrp(task_pgrp(current), SIGTTOU, 1);
+ kill_pgrp(pgrp, SIGTTOU, 1);
+ rcu_read_unlock();
set_thread_flag(TIF_SIGPENDING);
ret = -ERESTARTSYS;
-out:
return ret;
out_unlock:
spin_unlock_irqrestore(&tty->ctrl_lock, flags);
+out_rcuunlock:
+ rcu_read_unlock();
return ret;
}
@@ -524,7 +536,8 @@ static void __proc_set_tty(struct tty_struct *tty)
spin_unlock_irqrestore(&tty->ctrl_lock, flags);
tty->session = get_pid(task_session(current));
if (current->signal->tty) {
- printk(KERN_DEBUG "tty not NULL!!\n");
+ tty_debug(tty, "current tty %s not NULL!!\n",
+ current->signal->tty->name);
tty_kref_put(current->signal->tty);
}
put_pid(current->signal->tty_old_pgrp);
@@ -766,9 +779,7 @@ static void do_tty_hangup(struct work_struct *work)
void tty_hangup(struct tty_struct *tty)
{
-#ifdef TTY_DEBUG_HANGUP
- printk(KERN_DEBUG "%s hangup...\n", tty_name(tty));
-#endif
+ tty_debug_hangup(tty, "\n");
schedule_work(&tty->hangup_work);
}
@@ -785,9 +796,7 @@ EXPORT_SYMBOL(tty_hangup);
void tty_vhangup(struct tty_struct *tty)
{
-#ifdef TTY_DEBUG_HANGUP
- printk(KERN_DEBUG "%s vhangup...\n", tty_name(tty));
-#endif
+ tty_debug_hangup(tty, "\n");
__tty_hangup(tty, 0);
}
@@ -824,9 +833,7 @@ void tty_vhangup_self(void)
static void tty_vhangup_session(struct tty_struct *tty)
{
-#ifdef TTY_DEBUG_HANGUP
- printk(KERN_DEBUG "%s vhangup session...\n", tty_name(tty));
-#endif
+ tty_debug_hangup(tty, "\n");
__tty_hangup(tty, 1);
}
@@ -920,12 +927,8 @@ void disassociate_ctty(int on_exit)
tty->pgrp = NULL;
spin_unlock_irqrestore(&tty->ctrl_lock, flags);
tty_kref_put(tty);
- } else {
-#ifdef TTY_DEBUG_HANGUP
- printk(KERN_DEBUG "error attempted to write to tty [0x%p]"
- " = NULL", tty);
-#endif
- }
+ } else
+ tty_debug_hangup(tty, "no current tty\n");
spin_unlock_irq(&current->sighand->siglock);
/* Now clear signal->tty under the lock */
@@ -1279,18 +1282,22 @@ int tty_send_xchar(struct tty_struct *tty, char ch)
int was_stopped = tty->stopped;
if (tty->ops->send_xchar) {
+ down_read(&tty->termios_rwsem);
tty->ops->send_xchar(tty, ch);
+ up_read(&tty->termios_rwsem);
return 0;
}
if (tty_write_lock(tty, 0) < 0)
return -ERESTARTSYS;
+ down_read(&tty->termios_rwsem);
if (was_stopped)
start_tty(tty);
tty->ops->write(tty, &ch, 1);
if (was_stopped)
stop_tty(tty);
+ up_read(&tty->termios_rwsem);
tty_write_unlock(tty);
return 0;
}
@@ -1705,8 +1712,7 @@ static int tty_release_checks(struct tty_struct *tty, int idx)
{
#ifdef TTY_PARANOIA_CHECK
if (idx < 0 || idx >= tty->driver->num) {
- printk(KERN_DEBUG "%s: bad idx when trying to free (%s)\n",
- __func__, tty->name);
+ tty_debug(tty, "bad idx %d\n", idx);
return -1;
}
@@ -1715,20 +1721,20 @@ static int tty_release_checks(struct tty_struct *tty, int idx)
return 0;
if (tty != tty->driver->ttys[idx]) {
- printk(KERN_DEBUG "%s: driver.table[%d] not tty for (%s)\n",
- __func__, idx, tty->name);
+ tty_debug(tty, "bad driver table[%d] = %p\n",
+ idx, tty->driver->ttys[idx]);
return -1;
}
if (tty->driver->other) {
struct tty_struct *o_tty = tty->link;
if (o_tty != tty->driver->other->ttys[idx]) {
- printk(KERN_DEBUG "%s: other->table[%d] not o_tty for (%s)\n",
- __func__, idx, tty->name);
+ tty_debug(tty, "bad other table[%d] = %p\n",
+ idx, tty->driver->other->ttys[idx]);
return -1;
}
if (o_tty->link != tty) {
- printk(KERN_DEBUG "%s: bad pty pointers\n", __func__);
+ tty_debug(tty, "bad link = %p\n", o_tty->link);
return -1;
}
}
@@ -1782,10 +1788,7 @@ int tty_release(struct inode *inode, struct file *filp)
return 0;
}
-#ifdef TTY_DEBUG_HANGUP
- printk(KERN_DEBUG "%s: %s (tty count=%d)...\n", __func__,
- tty_name(tty), tty->count);
-#endif
+ tty_debug_hangup(tty, "(tty count=%d)...\n", tty->count);
if (tty->ops->close)
tty->ops->close(tty, filp);
@@ -1895,9 +1898,7 @@ int tty_release(struct inode *inode, struct file *filp)
if (!final)
return 0;
-#ifdef TTY_DEBUG_HANGUP
- printk(KERN_DEBUG "%s: %s: final close\n", __func__, tty_name(tty));
-#endif
+ tty_debug_hangup(tty, "final close\n");
/*
* Ask the line discipline code to release its structures
*/
@@ -1906,10 +1907,7 @@ int tty_release(struct inode *inode, struct file *filp)
/* Wait for pending work before tty destruction commmences */
tty_flush_works(tty);
-#ifdef TTY_DEBUG_HANGUP
- printk(KERN_DEBUG "%s: %s: freeing structure...\n", __func__,
- tty_name(tty));
-#endif
+ tty_debug_hangup(tty, "freeing structure...\n");
/*
* The release_tty function takes care of the details of clearing
* the slots and preserving the termios structure. The tty_unlock_pair
@@ -2098,9 +2096,9 @@ retry_open:
if (tty->driver->type == TTY_DRIVER_TYPE_PTY &&
tty->driver->subtype == PTY_TYPE_MASTER)
noctty = 1;
-#ifdef TTY_DEBUG_HANGUP
- printk(KERN_DEBUG "%s: opening %s...\n", __func__, tty->name);
-#endif
+
+ tty_debug_hangup(tty, "(tty count=%d)\n", tty->count);
+
if (tty->ops->open)
retval = tty->ops->open(tty, filp);
else
@@ -2108,10 +2106,8 @@ retry_open:
filp->f_flags = saved_flags;
if (retval) {
-#ifdef TTY_DEBUG_HANGUP
- printk(KERN_DEBUG "%s: error %d in opening %s...\n", __func__,
- retval, tty->name);
-#endif
+ tty_debug_hangup(tty, "error %d, releasing...\n", retval);
+
tty_unlock(tty); /* need to call tty_release without BTM */
tty_release(inode, filp);
if (retval != -ERESTARTSYS)
@@ -3182,10 +3178,18 @@ struct class *tty_class;
static int tty_cdev_add(struct tty_driver *driver, dev_t dev,
unsigned int index, unsigned int count)
{
+ int err;
+
/* init here, since reused cdevs cause crashes */
- cdev_init(&driver->cdevs[index], &tty_fops);
- driver->cdevs[index].owner = driver->owner;
- return cdev_add(&driver->cdevs[index], dev, count);
+ driver->cdevs[index] = cdev_alloc();
+ if (!driver->cdevs[index])
+ return -ENOMEM;
+ driver->cdevs[index]->ops = &tty_fops;
+ driver->cdevs[index]->owner = driver->owner;
+ err = cdev_add(driver->cdevs[index], dev, count);
+ if (err)
+ kobject_put(&driver->cdevs[index]->kobj);
+ return err;
}
/**
@@ -3291,8 +3295,10 @@ struct device *tty_register_device_attr(struct tty_driver *driver,
error:
put_device(dev);
- if (cdev)
- cdev_del(&driver->cdevs[index]);
+ if (cdev) {
+ cdev_del(driver->cdevs[index]);
+ driver->cdevs[index] = NULL;
+ }
return ERR_PTR(retval);
}
EXPORT_SYMBOL_GPL(tty_register_device_attr);
@@ -3312,8 +3318,10 @@ void tty_unregister_device(struct tty_driver *driver, unsigned index)
{
device_destroy(tty_class,
MKDEV(driver->major, driver->minor_start) + index);
- if (!(driver->flags & TTY_DRIVER_DYNAMIC_ALLOC))
- cdev_del(&driver->cdevs[index]);
+ if (!(driver->flags & TTY_DRIVER_DYNAMIC_ALLOC)) {
+ cdev_del(driver->cdevs[index]);
+ driver->cdevs[index] = NULL;
+ }
}
EXPORT_SYMBOL(tty_unregister_device);
@@ -3378,6 +3386,7 @@ err_free_all:
kfree(driver->ports);
kfree(driver->ttys);
kfree(driver->termios);
+ kfree(driver->cdevs);
kfree(driver);
return ERR_PTR(err);
}
@@ -3406,7 +3415,7 @@ static void destruct_tty_driver(struct kref *kref)
}
proc_tty_unregister_driver(driver);
if (driver->flags & TTY_DRIVER_DYNAMIC_ALLOC)
- cdev_del(&driver->cdevs[0]);
+ cdev_del(driver->cdevs[0]);
}
kfree(driver->cdevs);
kfree(driver->ports);