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[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index] [Xen-changelog] [xen-unstable] [LINUX] The removal of the console_use_vt hack was premature: it's still
# HG changeset patch
# User Steven Smith <ssmith@xxxxxxxxxxxxx>
# Node ID d5d8aeb4fa3412833202ebf7d5e7f1df4e94f220
# Parent 000609d8c93fb24b2ca5dd7961dfae19ddb0022f
[LINUX] The removal of the console_use_vt hack was premature: it's still
required if CONFIG_VT is enabled but the domain isn't currently
configured to use the PV framebuffer. Put it back in, in a slightly
more palatable form.
Signed-off-by: Steven Smith <sos22@xxxxxxxxx>
---
linux-2.6-xen-sparse/arch/i386/kernel/setup-xen.c | 1
linux-2.6-xen-sparse/arch/ia64/kernel/setup.c | 6
linux-2.6-xen-sparse/arch/x86_64/kernel/setup-xen.c | 3
linux-2.6-xen-sparse/drivers/char/tty_io.c | 3264 ++++++++++++++++++++
linux-2.6-xen-sparse/drivers/xen/console/console.c | 36
linux-2.6-xen-sparse/include/xen/xencons.h | 2
6 files changed, 3292 insertions(+), 20 deletions(-)
diff -r 000609d8c93f -r d5d8aeb4fa34
linux-2.6-xen-sparse/arch/i386/kernel/setup-xen.c
--- a/linux-2.6-xen-sparse/arch/i386/kernel/setup-xen.c Fri Dec 01 11:49:30
2006 +0000
+++ b/linux-2.6-xen-sparse/arch/i386/kernel/setup-xen.c Fri Dec 01 11:52:33
2006 +0000
@@ -1871,6 +1871,7 @@ void __init setup_arch(char **cmdline_p)
conswitchp = &dummy_con;
#endif
}
+ xencons_early_setup();
}
static int
diff -r 000609d8c93f -r d5d8aeb4fa34
linux-2.6-xen-sparse/arch/ia64/kernel/setup.c
--- a/linux-2.6-xen-sparse/arch/ia64/kernel/setup.c Fri Dec 01 11:49:30
2006 +0000
+++ b/linux-2.6-xen-sparse/arch/ia64/kernel/setup.c Fri Dec 01 11:52:33
2006 +0000
@@ -555,8 +555,10 @@ setup_arch (char **cmdline_p)
#endif
}
}
-#endif
-#endif
+ xencons_early_setup();
+#endif
+#endif
+
/* enable IA-64 Machine Check Abort Handling unless disabled */
if (!strstr(saved_command_line, "nomca"))
diff -r 000609d8c93f -r d5d8aeb4fa34
linux-2.6-xen-sparse/arch/x86_64/kernel/setup-xen.c
--- a/linux-2.6-xen-sparse/arch/x86_64/kernel/setup-xen.c Fri Dec 01
11:49:30 2006 +0000
+++ b/linux-2.6-xen-sparse/arch/x86_64/kernel/setup-xen.c Fri Dec 01
11:52:33 2006 +0000
@@ -984,10 +984,11 @@ void __init setup_arch(char **cmdline_p)
#endif
} else {
#if defined(CONFIG_VT) && defined(CONFIG_DUMMY_CONSOLE)
- conswitchp = &dummy_con;
+ conswitchp = &dummy_con;
#endif
}
}
+ xencons_early_setup();
#else /* CONFIG_XEN */
#ifdef CONFIG_VT
diff -r 000609d8c93f -r d5d8aeb4fa34
linux-2.6-xen-sparse/drivers/xen/console/console.c
--- a/linux-2.6-xen-sparse/drivers/xen/console/console.c Fri Dec 01
11:49:30 2006 +0000
+++ b/linux-2.6-xen-sparse/drivers/xen/console/console.c Fri Dec 01
11:52:33 2006 +0000
@@ -66,14 +66,14 @@
* 'xencons=tty' [XC_TTY]: Console attached to '/dev/tty[0-9]+'.
* 'xencons=ttyS' [XC_SERIAL]: Console attached to '/dev/ttyS[0-9]+'.
* 'xencons=xvc' [XC_XVC]: Console attached to '/dev/xvc0'.
- * [XC_DEFAULT]: DOM0 -> XC_SERIAL ; all others -> XC_TTY.
+ * default: DOM0 -> XC_SERIAL ; all others -> XC_TTY.
*
* NB. In mode XC_TTY, we create dummy consoles for tty2-63. This suppresses
* warnings from standard distro startup scripts.
*/
static enum {
- XC_OFF, XC_DEFAULT, XC_TTY, XC_SERIAL, XC_XVC
-} xc_mode = XC_DEFAULT;
+ XC_OFF, XC_TTY, XC_SERIAL, XC_XVC
+} xc_mode;
static int xc_num = -1;
/* /dev/xvc0 device number allocated by lanana.org. */
@@ -85,17 +85,32 @@ extern int sysrq_enabled;
extern int sysrq_enabled;
#endif
+void xencons_early_setup(void)
+{
+ extern int console_use_vt;
+
+ if (is_initial_xendomain()) {
+ xc_mode = XC_SERIAL;
+ } else {
+ xc_mode = XC_TTY;
+ console_use_vt = 0;
+ }
+}
+
static int __init xencons_setup(char *str)
{
char *q;
int n;
-
+ extern int console_use_vt;
+
+ console_use_vt = 1;
if (!strncmp(str, "ttyS", 4)) {
xc_mode = XC_SERIAL;
str += 4;
} else if (!strncmp(str, "tty", 3)) {
xc_mode = XC_TTY;
str += 3;
+ console_use_vt = 0;
} else if (!strncmp(str, "xvc", 3)) {
xc_mode = XC_XVC;
str += 3;
@@ -193,14 +208,10 @@ static int __init xen_console_init(void)
goto out;
if (is_initial_xendomain()) {
- if (xc_mode == XC_DEFAULT)
- xc_mode = XC_SERIAL;
kcons_info.write = kcons_write_dom0;
} else {
if (!xen_start_info->console.domU.evtchn)
goto out;
- if (xc_mode == XC_DEFAULT)
- xc_mode = XC_TTY;
kcons_info.write = kcons_write;
}
@@ -699,15 +710,6 @@ static int __init xencons_init(void)
printk("Xen virtual console successfully installed as %s%d\n",
DRV(xencons_driver)->name, xc_num);
- /* Check about framebuffer messing up the console */
- if (!is_initial_xendomain() &&
- !xenbus_exists(XBT_NIL, "device", "vfb")) {
- /* FIXME: this is ugly */
- unregister_console(&kcons_info);
- kcons_info.flags |= CON_CONSDEV;
- register_console(&kcons_info);
- }
-
return 0;
}
diff -r 000609d8c93f -r d5d8aeb4fa34 linux-2.6-xen-sparse/include/xen/xencons.h
--- a/linux-2.6-xen-sparse/include/xen/xencons.h Fri Dec 01 11:49:30
2006 +0000
+++ b/linux-2.6-xen-sparse/include/xen/xencons.h Fri Dec 01 11:52:33
2006 +0000
@@ -14,4 +14,6 @@ int xencons_ring_init(void);
int xencons_ring_init(void);
int xencons_ring_send(const char *data, unsigned len);
+void xencons_early_setup(void);
+
#endif /* __ASM_XENCONS_H__ */
diff -r 000609d8c93f -r d5d8aeb4fa34 linux-2.6-xen-sparse/drivers/char/tty_io.c
--- /dev/null Thu Jan 01 00:00:00 1970 +0000
+++ b/linux-2.6-xen-sparse/drivers/char/tty_io.c Fri Dec 01 11:52:33
2006 +0000
@@ -0,0 +1,3264 @@
+/*
+ * linux/drivers/char/tty_io.c
+ *
+ * Copyright (C) 1991, 1992 Linus Torvalds
+ */
+
+/*
+ * 'tty_io.c' gives an orthogonal feeling to tty's, be they consoles
+ * or rs-channels. It also implements echoing, cooked mode etc.
+ *
+ * Kill-line thanks to John T Kohl, who also corrected VMIN = VTIME = 0.
+ *
+ * Modified by Theodore Ts'o, 9/14/92, to dynamically allocate the
+ * tty_struct and tty_queue structures. Previously there was an array
+ * of 256 tty_struct's which was statically allocated, and the
+ * tty_queue structures were allocated at boot time. Both are now
+ * dynamically allocated only when the tty is open.
+ *
+ * Also restructured routines so that there is more of a separation
+ * between the high-level tty routines (tty_io.c and tty_ioctl.c) and
+ * the low-level tty routines (serial.c, pty.c, console.c). This
+ * makes for cleaner and more compact code. -TYT, 9/17/92
+ *
+ * Modified by Fred N. van Kempen, 01/29/93, to add line disciplines
+ * which can be dynamically activated and de-activated by the line
+ * discipline handling modules (like SLIP).
+ *
+ * NOTE: pay no attention to the line discipline code (yet); its
+ * interface is still subject to change in this version...
+ * -- TYT, 1/31/92
+ *
+ * Added functionality to the OPOST tty handling. No delays, but all
+ * other bits should be there.
+ * -- Nick Holloway <alfie@xxxxxxxxxxxxxxxxx>, 27th May 1993.
+ *
+ * Rewrote canonical mode and added more termios flags.
+ * -- julian@xxxxxxxxxxxxxxxxxxxxxx (J. Cowley), 13Jan94
+ *
+ * Reorganized FASYNC support so mouse code can share it.
+ * -- ctm@xxxxxxxx, 9Sep95
+ *
+ * New TIOCLINUX variants added.
+ * -- mj@xxxxxxxxxxxxxxxxx, 19-Nov-95
+ *
+ * Restrict vt switching via ioctl()
+ * -- grif@xxxxxxxxxx, 5-Dec-95
+ *
+ * Move console and virtual terminal code to more appropriate files,
+ * implement CONFIG_VT and generalize console device interface.
+ * -- Marko Kohtala <Marko.Kohtala@xxxxxx>, March 97
+ *
+ * Rewrote init_dev and release_dev to eliminate races.
+ * -- Bill Hawes <whawes@xxxxxxxx>, June 97
+ *
+ * Added devfs support.
+ * -- C. Scott Ananian <cananian@xxxxxxxxxxxxxxxxxxxx>, 13-Jan-1998
+ *
+ * Added support for a Unix98-style ptmx device.
+ * -- C. Scott Ananian <cananian@xxxxxxxxxxxxxxxxxxxx>, 14-Jan-1998
+ *
+ * Reduced memory usage for older ARM systems
+ * -- Russell King <rmk@xxxxxxxxxxxxxxxx>
+ *
+ * Move do_SAK() into process context. Less stack use in devfs functions.
+ * alloc_tty_struct() always uses kmalloc() -- Andrew Morton
<andrewm@xxxxxxxxxx> 17Mar01
+ */
+
+#include <linux/config.h>
+#include <linux/types.h>
+#include <linux/major.h>
+#include <linux/errno.h>
+#include <linux/signal.h>
+#include <linux/fcntl.h>
+#include <linux/sched.h>
+#include <linux/interrupt.h>
+#include <linux/tty.h>
+#include <linux/tty_driver.h>
+#include <linux/tty_flip.h>
+#include <linux/devpts_fs.h>
+#include <linux/file.h>
+#include <linux/console.h>
+#include <linux/timer.h>
+#include <linux/ctype.h>
+#include <linux/kd.h>
+#include <linux/mm.h>
+#include <linux/string.h>
+#include <linux/slab.h>
+#include <linux/poll.h>
+#include <linux/proc_fs.h>
+#include <linux/init.h>
+#include <linux/module.h>
+#include <linux/smp_lock.h>
+#include <linux/device.h>
+#include <linux/idr.h>
+#include <linux/wait.h>
+#include <linux/bitops.h>
+#include <linux/delay.h>
+
+#include <asm/uaccess.h>
+#include <asm/system.h>
+
+#include <linux/kbd_kern.h>
+#include <linux/vt_kern.h>
+#include <linux/selection.h>
+#include <linux/devfs_fs_kernel.h>
+
+#include <linux/kmod.h>
+
+#undef TTY_DEBUG_HANGUP
+
+#define TTY_PARANOIA_CHECK 1
+#define CHECK_TTY_COUNT 1
+
+struct termios tty_std_termios = { /* for the benefit of tty drivers */
+ .c_iflag = ICRNL | IXON,
+ .c_oflag = OPOST | ONLCR,
+ .c_cflag = B38400 | CS8 | CREAD | HUPCL,
+ .c_lflag = ISIG | ICANON | ECHO | ECHOE | ECHOK |
+ ECHOCTL | ECHOKE | IEXTEN,
+ .c_cc = INIT_C_CC
+};
+
+EXPORT_SYMBOL(tty_std_termios);
+
+/* This list gets poked at by procfs and various bits of boot up code. This
+ could do with some rationalisation such as pulling the tty proc function
+ into this file */
+
+LIST_HEAD(tty_drivers); /* linked list of tty drivers */
+
+/* Semaphore to protect creating and releasing a tty. This is shared with
+ vt.c for deeply disgusting hack reasons */
+DECLARE_MUTEX(tty_sem);
+
+int console_use_vt = 1;
+
+#ifdef CONFIG_UNIX98_PTYS
+extern struct tty_driver *ptm_driver; /* Unix98 pty masters; for /dev/ptmx */
+extern int pty_limit; /* Config limit on Unix98 ptys */
+static DEFINE_IDR(allocated_ptys);
+static DECLARE_MUTEX(allocated_ptys_lock);
+static int ptmx_open(struct inode *, struct file *);
+#endif
+
+extern void disable_early_printk(void);
+
+static void initialize_tty_struct(struct tty_struct *tty);
+
+static ssize_t tty_read(struct file *, char __user *, size_t, loff_t *);
+static ssize_t tty_write(struct file *, const char __user *, size_t, loff_t *);
+ssize_t redirected_tty_write(struct file *, const char __user *, size_t,
loff_t *);
+static unsigned int tty_poll(struct file *, poll_table *);
+static int tty_open(struct inode *, struct file *);
+static int tty_release(struct inode *, struct file *);
+int tty_ioctl(struct inode * inode, struct file * file,
+ unsigned int cmd, unsigned long arg);
+static int tty_fasync(int fd, struct file * filp, int on);
+static void release_mem(struct tty_struct *tty, int idx);
+
+
+static struct tty_struct *alloc_tty_struct(void)
+{
+ struct tty_struct *tty;
+
+ tty = kmalloc(sizeof(struct tty_struct), GFP_KERNEL);
+ if (tty)
+ memset(tty, 0, sizeof(struct tty_struct));
+ return tty;
+}
+
+static void tty_buffer_free_all(struct tty_struct *);
+
+static inline void free_tty_struct(struct tty_struct *tty)
+{
+ kfree(tty->write_buf);
+ tty_buffer_free_all(tty);
+ kfree(tty);
+}
+
+#define TTY_NUMBER(tty) ((tty)->index + (tty)->driver->name_base)
+
+char *tty_name(struct tty_struct *tty, char *buf)
+{
+ if (!tty) /* Hmm. NULL pointer. That's fun. */
+ strcpy(buf, "NULL tty");
+ else
+ strcpy(buf, tty->name);
+ return buf;
+}
+
+EXPORT_SYMBOL(tty_name);
+
+int tty_paranoia_check(struct tty_struct *tty, struct inode *inode,
+ const char *routine)
+{
+#ifdef TTY_PARANOIA_CHECK
+ if (!tty) {
+ printk(KERN_WARNING
+ "null TTY for (%d:%d) in %s\n",
+ imajor(inode), iminor(inode), routine);
+ return 1;
+ }
+ if (tty->magic != TTY_MAGIC) {
+ printk(KERN_WARNING
+ "bad magic number for tty struct (%d:%d) in %s\n",
+ imajor(inode), iminor(inode), routine);
+ return 1;
+ }
+#endif
+ return 0;
+}
+
+static int check_tty_count(struct tty_struct *tty, const char *routine)
+{
+#ifdef CHECK_TTY_COUNT
+ struct list_head *p;
+ int count = 0;
+
+ file_list_lock();
+ list_for_each(p, &tty->tty_files) {
+ count++;
+ }
+ file_list_unlock();
+ if (tty->driver->type == TTY_DRIVER_TYPE_PTY &&
+ tty->driver->subtype == PTY_TYPE_SLAVE &&
+ tty->link && tty->link->count)
+ count++;
+ if (tty->count != count) {
+ printk(KERN_WARNING "Warning: dev (%s) tty->count(%d) "
+ "!= #fd's(%d) in %s\n",
+ tty->name, tty->count, count, routine);
+ return count;
+ }
+#endif
+ return 0;
+}
+
+/*
+ * Tty buffer allocation management
+ */
+
+static void tty_buffer_free_all(struct tty_struct *tty)
+{
+ struct tty_buffer *thead;
+ while((thead = tty->buf.head) != NULL) {
+ tty->buf.head = thead->next;
+ kfree(thead);
+ }
+ while((thead = tty->buf.free) != NULL) {
+ tty->buf.free = thead->next;
+ kfree(thead);
+ }
+ tty->buf.tail = NULL;
+}
+
+static void tty_buffer_init(struct tty_struct *tty)
+{
+ spin_lock_init(&tty->buf.lock);
+ tty->buf.head = NULL;
+ tty->buf.tail = NULL;
+ tty->buf.free = NULL;
+}
+
+static struct tty_buffer *tty_buffer_alloc(size_t size)
+{
+ struct tty_buffer *p = kmalloc(sizeof(struct tty_buffer) + 2 * size,
GFP_ATOMIC);
+ if(p == NULL)
+ return NULL;
+ p->used = 0;
+ p->size = size;
+ p->next = NULL;
+ p->active = 0;
+ p->commit = 0;
+ p->read = 0;
+ p->char_buf_ptr = (char *)(p->data);
+ p->flag_buf_ptr = (unsigned char *)p->char_buf_ptr + size;
+/* printk("Flip create %p\n", p); */
+ return p;
+}
+
+/* Must be called with the tty_read lock held. This needs to acquire strategy
+ code to decide if we should kfree or relink a given expired buffer */
+
+static void tty_buffer_free(struct tty_struct *tty, struct tty_buffer *b)
+{
+ /* Dumb strategy for now - should keep some stats */
+/* printk("Flip dispose %p\n", b); */
+ if(b->size >= 512)
+ kfree(b);
+ else {
+ b->next = tty->buf.free;
+ tty->buf.free = b;
+ }
+}
+
+static struct tty_buffer *tty_buffer_find(struct tty_struct *tty, size_t size)
+{
+ struct tty_buffer **tbh = &tty->buf.free;
+ while((*tbh) != NULL) {
+ struct tty_buffer *t = *tbh;
+ if(t->size >= size) {
+ *tbh = t->next;
+ t->next = NULL;
+ t->used = 0;
+ t->commit = 0;
+ t->read = 0;
+ /* DEBUG ONLY */
+/* memset(t->data, '*', size); */
+/* printk("Flip recycle %p\n", t); */
+ return t;
+ }
+ tbh = &((*tbh)->next);
+ }
+ /* Round the buffer size out */
+ size = (size + 0xFF) & ~ 0xFF;
+ return tty_buffer_alloc(size);
+ /* Should possibly check if this fails for the largest buffer we
+ have queued and recycle that ? */
+}
+
+int tty_buffer_request_room(struct tty_struct *tty, size_t size)
+{
+ struct tty_buffer *b, *n;
+ int left;
+ unsigned long flags;
+
+ spin_lock_irqsave(&tty->buf.lock, flags);
+
+ /* OPTIMISATION: We could keep a per tty "zero" sized buffer to
+ remove this conditional if its worth it. This would be invisible
+ to the callers */
+ if ((b = tty->buf.tail) != NULL) {
+ left = b->size - b->used;
+ b->active = 1;
+ } else
+ left = 0;
+
+ if (left < size) {
+ /* This is the slow path - looking for new buffers to use */
+ if ((n = tty_buffer_find(tty, size)) != NULL) {
+ if (b != NULL) {
+ b->next = n;
+ b->active = 0;
+ b->commit = b->used;
+ } else
+ tty->buf.head = n;
+ tty->buf.tail = n;
+ n->active = 1;
+ } else
+ size = left;
+ }
+
+ spin_unlock_irqrestore(&tty->buf.lock, flags);
+ return size;
+}
+
+EXPORT_SYMBOL_GPL(tty_buffer_request_room);
+
+int tty_insert_flip_string(struct tty_struct *tty, unsigned char *chars,
size_t size)
+{
+ int copied = 0;
+ do {
+ int space = tty_buffer_request_room(tty, size - copied);
+ struct tty_buffer *tb = tty->buf.tail;
+ /* If there is no space then tb may be NULL */
+ if(unlikely(space == 0))
+ break;
+ memcpy(tb->char_buf_ptr + tb->used, chars, space);
+ memset(tb->flag_buf_ptr + tb->used, TTY_NORMAL, space);
+ tb->used += space;
+ copied += space;
+ chars += space;
+/* printk("Flip insert %d.\n", space); */
+ }
+ /* There is a small chance that we need to split the data over
+ several buffers. If this is the case we must loop */
+ while (unlikely(size > copied));
+ return copied;
+}
+
+EXPORT_SYMBOL_GPL(tty_insert_flip_string);
+
+int tty_insert_flip_string_flags(struct tty_struct *tty, unsigned char *chars,
char *flags, size_t size)
+{
+ int copied = 0;
+ do {
+ int space = tty_buffer_request_room(tty, size - copied);
+ struct tty_buffer *tb = tty->buf.tail;
+ /* If there is no space then tb may be NULL */
+ if(unlikely(space == 0))
+ break;
+ memcpy(tb->char_buf_ptr + tb->used, chars, space);
+ memcpy(tb->flag_buf_ptr + tb->used, flags, space);
+ tb->used += space;
+ copied += space;
+ chars += space;
+ flags += space;
+ }
+ /* There is a small chance that we need to split the data over
+ several buffers. If this is the case we must loop */
+ while (unlikely(size > copied));
+ return copied;
+}
+
+EXPORT_SYMBOL_GPL(tty_insert_flip_string_flags);
+
+
+/*
+ * Prepare a block of space in the buffer for data. Returns the length
+ * available and buffer pointer to the space which is now allocated and
+ * accounted for as ready for normal characters. This is used for drivers
+ * that need their own block copy routines into the buffer. There is no
+ * guarantee the buffer is a DMA target!
+ */
+
+int tty_prepare_flip_string(struct tty_struct *tty, unsigned char **chars,
size_t size)
+{
+ int space = tty_buffer_request_room(tty, size);
+ if (likely(space)) {
+ struct tty_buffer *tb = tty->buf.tail;
+ *chars = tb->char_buf_ptr + tb->used;
+ memset(tb->flag_buf_ptr + tb->used, TTY_NORMAL, space);
+ tb->used += space;
+ }
+ return space;
+}
+
+EXPORT_SYMBOL_GPL(tty_prepare_flip_string);
+
+/*
+ * Prepare a block of space in the buffer for data. Returns the length
+ * available and buffer pointer to the space which is now allocated and
+ * accounted for as ready for characters. This is used for drivers
+ * that need their own block copy routines into the buffer. There is no
+ * guarantee the buffer is a DMA target!
+ */
+
+int tty_prepare_flip_string_flags(struct tty_struct *tty, unsigned char
**chars, char **flags, size_t size)
+{
+ int space = tty_buffer_request_room(tty, size);
+ if (likely(space)) {
+ struct tty_buffer *tb = tty->buf.tail;
+ *chars = tb->char_buf_ptr + tb->used;
+ *flags = tb->flag_buf_ptr + tb->used;
+ tb->used += space;
+ }
+ return space;
+}
+
+EXPORT_SYMBOL_GPL(tty_prepare_flip_string_flags);
+
+
+
+/*
+ * This is probably overkill for real world processors but
+ * they are not on hot paths so a little discipline won't do
+ * any harm.
+ */
+
+static void tty_set_termios_ldisc(struct tty_struct *tty, int num)
+{
+ down(&tty->termios_sem);
+ tty->termios->c_line = num;
+ up(&tty->termios_sem);
+}
+
+/*
+ * This guards the refcounted line discipline lists. The lock
+ * must be taken with irqs off because there are hangup path
+ * callers who will do ldisc lookups and cannot sleep.
+ */
+
+static DEFINE_SPINLOCK(tty_ldisc_lock);
+static DECLARE_WAIT_QUEUE_HEAD(tty_ldisc_wait);
+static struct tty_ldisc tty_ldiscs[NR_LDISCS]; /* line disc dispatch table */
+
+int tty_register_ldisc(int disc, struct tty_ldisc *new_ldisc)
+{
+ unsigned long flags;
+ int ret = 0;
+
+ if (disc < N_TTY || disc >= NR_LDISCS)
+ return -EINVAL;
+
+ spin_lock_irqsave(&tty_ldisc_lock, flags);
+ tty_ldiscs[disc] = *new_ldisc;
+ tty_ldiscs[disc].num = disc;
+ tty_ldiscs[disc].flags |= LDISC_FLAG_DEFINED;
+ tty_ldiscs[disc].refcount = 0;
+ spin_unlock_irqrestore(&tty_ldisc_lock, flags);
+
+ return ret;
+}
+EXPORT_SYMBOL(tty_register_ldisc);
+
+int tty_unregister_ldisc(int disc)
+{
+ unsigned long flags;
+ int ret = 0;
+
+ if (disc < N_TTY || disc >= NR_LDISCS)
+ return -EINVAL;
+
+ spin_lock_irqsave(&tty_ldisc_lock, flags);
+ if (tty_ldiscs[disc].refcount)
+ ret = -EBUSY;
+ else
+ tty_ldiscs[disc].flags &= ~LDISC_FLAG_DEFINED;
+ spin_unlock_irqrestore(&tty_ldisc_lock, flags);
+
+ return ret;
+}
+EXPORT_SYMBOL(tty_unregister_ldisc);
+
+struct tty_ldisc *tty_ldisc_get(int disc)
+{
+ unsigned long flags;
+ struct tty_ldisc *ld;
+
+ if (disc < N_TTY || disc >= NR_LDISCS)
+ return NULL;
+
+ spin_lock_irqsave(&tty_ldisc_lock, flags);
+
+ ld = &tty_ldiscs[disc];
+ /* Check the entry is defined */
+ if(ld->flags & LDISC_FLAG_DEFINED)
+ {
+ /* If the module is being unloaded we can't use it */
+ if (!try_module_get(ld->owner))
+ ld = NULL;
+ else /* lock it */
+ ld->refcount++;
+ }
+ else
+ ld = NULL;
+ spin_unlock_irqrestore(&tty_ldisc_lock, flags);
+ return ld;
+}
+
+EXPORT_SYMBOL_GPL(tty_ldisc_get);
+
+void tty_ldisc_put(int disc)
+{
+ struct tty_ldisc *ld;
+ unsigned long flags;
+
+ if (disc < N_TTY || disc >= NR_LDISCS)
+ BUG();
+
+ spin_lock_irqsave(&tty_ldisc_lock, flags);
+ ld = &tty_ldiscs[disc];
+ if(ld->refcount == 0)
+ BUG();
+ ld->refcount --;
+ module_put(ld->owner);
+ spin_unlock_irqrestore(&tty_ldisc_lock, flags);
+}
+
+EXPORT_SYMBOL_GPL(tty_ldisc_put);
+
+static void tty_ldisc_assign(struct tty_struct *tty, struct tty_ldisc *ld)
+{
+ tty->ldisc = *ld;
+ tty->ldisc.refcount = 0;
+}
+
+/**
+ * tty_ldisc_try - internal helper
+ * @tty: the tty
+ *
+ * Make a single attempt to grab and bump the refcount on
+ * the tty ldisc. Return 0 on failure or 1 on success. This is
+ * used to implement both the waiting and non waiting versions
+ * of tty_ldisc_ref
+ */
+
+static int tty_ldisc_try(struct tty_struct *tty)
+{
+ unsigned long flags;
+ struct tty_ldisc *ld;
+ int ret = 0;
+
+ spin_lock_irqsave(&tty_ldisc_lock, flags);
+ ld = &tty->ldisc;
+ if(test_bit(TTY_LDISC, &tty->flags))
+ {
+ ld->refcount++;
+ ret = 1;
+ }
+ spin_unlock_irqrestore(&tty_ldisc_lock, flags);
+ return ret;
+}
+
+/**
+ * tty_ldisc_ref_wait - wait for the tty ldisc
+ * @tty: tty device
+ *
+ * Dereference the line discipline for the terminal and take a
+ * reference to it. If the line discipline is in flux then
+ * wait patiently until it changes.
+ *
+ * Note: Must not be called from an IRQ/timer context. The caller
+ * must also be careful not to hold other locks that will deadlock
+ * against a discipline change, such as an existing ldisc reference
+ * (which we check for)
+ */
+
+struct tty_ldisc *tty_ldisc_ref_wait(struct tty_struct *tty)
+{
+ /* wait_event is a macro */
+ wait_event(tty_ldisc_wait, tty_ldisc_try(tty));
+ if(tty->ldisc.refcount == 0)
+ printk(KERN_ERR "tty_ldisc_ref_wait\n");
+ return &tty->ldisc;
+}
+
+EXPORT_SYMBOL_GPL(tty_ldisc_ref_wait);
+
+/**
+ * tty_ldisc_ref - get the tty ldisc
+ * @tty: tty device
+ *
+ * Dereference the line discipline for the terminal and take a
+ * reference to it. If the line discipline is in flux then
+ * return NULL. Can be called from IRQ and timer functions.
+ */
+
+struct tty_ldisc *tty_ldisc_ref(struct tty_struct *tty)
+{
+ if(tty_ldisc_try(tty))
+ return &tty->ldisc;
+ return NULL;
+}
+
+EXPORT_SYMBOL_GPL(tty_ldisc_ref);
+
+/**
+ * tty_ldisc_deref - free a tty ldisc reference
+ * @ld: reference to free up
+ *
+ * Undoes the effect of tty_ldisc_ref or tty_ldisc_ref_wait. May
+ * be called in IRQ context.
+ */
+
+void tty_ldisc_deref(struct tty_ldisc *ld)
+{
+ unsigned long flags;
+
+ if(ld == NULL)
+ BUG();
+
+ spin_lock_irqsave(&tty_ldisc_lock, flags);
+ if(ld->refcount == 0)
+ printk(KERN_ERR "tty_ldisc_deref: no references.\n");
+ else
+ ld->refcount--;
+ if(ld->refcount == 0)
+ wake_up(&tty_ldisc_wait);
+ spin_unlock_irqrestore(&tty_ldisc_lock, flags);
+}
+
+EXPORT_SYMBOL_GPL(tty_ldisc_deref);
+
+/**
+ * tty_ldisc_enable - allow ldisc use
+ * @tty: terminal to activate ldisc on
+ *
+ * Set the TTY_LDISC flag when the line discipline can be called
+ * again. Do neccessary wakeups for existing sleepers.
+ *
+ * Note: nobody should set this bit except via this function. Clearing
+ * directly is allowed.
+ */
+
+static void tty_ldisc_enable(struct tty_struct *tty)
+{
+ set_bit(TTY_LDISC, &tty->flags);
+ wake_up(&tty_ldisc_wait);
+}
+
+/**
+ * tty_set_ldisc - set line discipline
+ * @tty: the terminal to set
+ * @ldisc: the line discipline
+ *
+ * Set the discipline of a tty line. Must be called from a process
+ * context.
+ */
+
+static int tty_set_ldisc(struct tty_struct *tty, int ldisc)
+{
+ int retval = 0;
+ struct tty_ldisc o_ldisc;
+ char buf[64];
+ int work;
+ unsigned long flags;
+ struct tty_ldisc *ld;
+ struct tty_struct *o_tty;
+
+ if ((ldisc < N_TTY) || (ldisc >= NR_LDISCS))
+ return -EINVAL;
+
+restart:
+
+ ld = tty_ldisc_get(ldisc);
+ /* Eduardo Blanco <ejbs@xxxxxxxxxxxx> */
+ /* Cyrus Durgin <cider@xxxxxxxxxxxxx> */
+ if (ld == NULL) {
+ request_module("tty-ldisc-%d", ldisc);
+ ld = tty_ldisc_get(ldisc);
+ }
+ if (ld == NULL)
+ return -EINVAL;
+
+ /*
+ * No more input please, we are switching. The new ldisc
+ * will update this value in the ldisc open function
+ */
+
+ tty->receive_room = 0;
+
+ /*
+ * Problem: What do we do if this blocks ?
+ */
+
+ tty_wait_until_sent(tty, 0);
+
+ if (tty->ldisc.num == ldisc) {
+ tty_ldisc_put(ldisc);
+ return 0;
+ }
+
+ o_ldisc = tty->ldisc;
+ o_tty = tty->link;
+
+ /*
+ * Make sure we don't change while someone holds a
+ * reference to the line discipline. The TTY_LDISC bit
+ * prevents anyone taking a reference once it is clear.
+ * We need the lock to avoid racing reference takers.
+ */
+
+ spin_lock_irqsave(&tty_ldisc_lock, flags);
+ if (tty->ldisc.refcount || (o_tty && o_tty->ldisc.refcount)) {
+ if(tty->ldisc.refcount) {
+ /* Free the new ldisc we grabbed. Must drop the lock
+ first. */
+ spin_unlock_irqrestore(&tty_ldisc_lock, flags);
+ tty_ldisc_put(ldisc);
+ /*
+ * There are several reasons we may be busy, including
+ * random momentary I/O traffic. We must therefore
+ * retry. We could distinguish between blocking ops
+ * and retries if we made tty_ldisc_wait() smarter. That
+ * is up for discussion.
+ */
+ if (wait_event_interruptible(tty_ldisc_wait,
tty->ldisc.refcount == 0) < 0)
+ return -ERESTARTSYS;
+ goto restart;
+ }
+ if(o_tty && o_tty->ldisc.refcount) {
+ spin_unlock_irqrestore(&tty_ldisc_lock, flags);
+ tty_ldisc_put(ldisc);
+ if (wait_event_interruptible(tty_ldisc_wait,
o_tty->ldisc.refcount == 0) < 0)
+ return -ERESTARTSYS;
+ goto restart;
+ }
+ }
+
+ /* if the TTY_LDISC bit is set, then we are racing against another
ldisc change */
+
+ if (!test_bit(TTY_LDISC, &tty->flags)) {
+ spin_unlock_irqrestore(&tty_ldisc_lock, flags);
+ tty_ldisc_put(ldisc);
+ ld = tty_ldisc_ref_wait(tty);
+ tty_ldisc_deref(ld);
+ goto restart;
+ }
+
+ clear_bit(TTY_LDISC, &tty->flags);
+ clear_bit(TTY_DONT_FLIP, &tty->flags);
+ if (o_tty) {
+ clear_bit(TTY_LDISC, &o_tty->flags);
+ clear_bit(TTY_DONT_FLIP, &o_tty->flags);
+ }
+ spin_unlock_irqrestore(&tty_ldisc_lock, flags);
+
+ /*
+ * From this point on we know nobody has an ldisc
+ * usage reference, nor can they obtain one until
+ * we say so later on.
+ */
+
+ work = cancel_delayed_work(&tty->buf.work);
+ /*
+ * Wait for ->hangup_work and ->buf.work handlers to terminate
+ */
+
+ flush_scheduled_work();
+ /* Shutdown the current discipline. */
+ if (tty->ldisc.close)
+ (tty->ldisc.close)(tty);
+
+ /* Now set up the new line discipline. */
+ tty_ldisc_assign(tty, ld);
+ tty_set_termios_ldisc(tty, ldisc);
+ if (tty->ldisc.open)
+ retval = (tty->ldisc.open)(tty);
+ if (retval < 0) {
+ tty_ldisc_put(ldisc);
+ /* There is an outstanding reference here so this is safe */
+ tty_ldisc_assign(tty, tty_ldisc_get(o_ldisc.num));
+ tty_set_termios_ldisc(tty, tty->ldisc.num);
+ if (tty->ldisc.open && (tty->ldisc.open(tty) < 0)) {
+ tty_ldisc_put(o_ldisc.num);
+ /* This driver is always present */
+ tty_ldisc_assign(tty, tty_ldisc_get(N_TTY));
+ tty_set_termios_ldisc(tty, N_TTY);
+ if (tty->ldisc.open) {
+ int r = tty->ldisc.open(tty);
+
+ if (r < 0)
+ panic("Couldn't open N_TTY ldisc for "
+ "%s --- error %d.",
+ tty_name(tty, buf), r);
+ }
+ }
+ }
+ /* At this point we hold a reference to the new ldisc and a
+ a reference to the old ldisc. If we ended up flipping back
+ to the existing ldisc we have two references to it */
+
+ if (tty->ldisc.num != o_ldisc.num && tty->driver->set_ldisc)
+ tty->driver->set_ldisc(tty);
+
+ tty_ldisc_put(o_ldisc.num);
+
+ /*
+ * Allow ldisc referencing to occur as soon as the driver
+ * ldisc callback completes.
+ */
+
+ tty_ldisc_enable(tty);
+ if (o_tty)
+ tty_ldisc_enable(o_tty);
+
+ /* Restart it in case no characters kick it off. Safe if
+ already running */
+ if (work)
+ schedule_delayed_work(&tty->buf.work, 1);
+ return retval;
+}
+
+/*
+ * This routine returns a tty driver structure, given a device number
+ */
+static struct tty_driver *get_tty_driver(dev_t device, int *index)
+{
+ struct tty_driver *p;
+
+ list_for_each_entry(p, &tty_drivers, tty_drivers) {
+ dev_t base = MKDEV(p->major, p->minor_start);
+ if (device < base || device >= base + p->num)
+ continue;
+ *index = device - base;
+ return p;
+ }
+ return NULL;
+}
+
+/*
+ * If we try to write to, or set the state of, a terminal and we're
+ * not in the foreground, send a SIGTTOU. If the signal is blocked or
+ * ignored, go ahead and perform the operation. (POSIX 7.2)
+ */
+int tty_check_change(struct tty_struct * tty)
+{
+ if (current->signal->tty != tty)
+ return 0;
+ if (tty->pgrp <= 0) {
+ printk(KERN_WARNING "tty_check_change: tty->pgrp <= 0!\n");
+ return 0;
+ }
+ if (process_group(current) == tty->pgrp)
+ return 0;
+ if (is_ignored(SIGTTOU))
+ return 0;
+ if (is_orphaned_pgrp(process_group(current)))
+ return -EIO;
+ (void) kill_pg(process_group(current), SIGTTOU, 1);
+ return -ERESTARTSYS;
+}
+
+EXPORT_SYMBOL(tty_check_change);
+
+static ssize_t hung_up_tty_read(struct file * file, char __user * buf,
+ size_t count, loff_t *ppos)
+{
+ return 0;
+}
+
+static ssize_t hung_up_tty_write(struct file * file, const char __user * buf,
+ size_t count, loff_t *ppos)
+{
+ return -EIO;
+}
+
+/* No kernel lock held - none needed ;) */
+static unsigned int hung_up_tty_poll(struct file * filp, poll_table * wait)
+{
+ return POLLIN | POLLOUT | POLLERR | POLLHUP | POLLRDNORM | POLLWRNORM;
+}
+
+static int hung_up_tty_ioctl(struct inode * inode, struct file * file,
+ unsigned int cmd, unsigned long arg)
+{
+ return cmd == TIOCSPGRP ? -ENOTTY : -EIO;
+}
+
+static struct file_operations tty_fops = {
+ .llseek = no_llseek,
+ .read = tty_read,
+ .write = tty_write,
+ .poll = tty_poll,
+ .ioctl = tty_ioctl,
+ .open = tty_open,
+ .release = tty_release,
+ .fasync = tty_fasync,
+};
+
+#ifdef CONFIG_UNIX98_PTYS
+static struct file_operations ptmx_fops = {
+ .llseek = no_llseek,
+ .read = tty_read,
+ .write = tty_write,
+ .poll = tty_poll,
+ .ioctl = tty_ioctl,
+ .open = ptmx_open,
+ .release = tty_release,
+ .fasync = tty_fasync,
+};
+#endif
+
+static struct file_operations console_fops = {
+ .llseek = no_llseek,
+ .read = tty_read,
+ .write = redirected_tty_write,
+ .poll = tty_poll,
+ .ioctl = tty_ioctl,
+ .open = tty_open,
+ .release = tty_release,
+ .fasync = tty_fasync,
+};
+
+static struct file_operations hung_up_tty_fops = {
+ .llseek = no_llseek,
+ .read = hung_up_tty_read,
+ .write = hung_up_tty_write,
+ .poll = hung_up_tty_poll,
+ .ioctl = hung_up_tty_ioctl,
+ .release = tty_release,
+};
+
+static DEFINE_SPINLOCK(redirect_lock);
+static struct file *redirect;
+
+/**
+ * tty_wakeup - request more data
+ * @tty: terminal
+ *
+ * Internal and external helper for wakeups of tty. This function
+ * informs the line discipline if present that the driver is ready
+ * to receive more output data.
+ */
+
+void tty_wakeup(struct tty_struct *tty)
+{
+ struct tty_ldisc *ld;
+
+ if (test_bit(TTY_DO_WRITE_WAKEUP, &tty->flags)) {
+ ld = tty_ldisc_ref(tty);
+ if(ld) {
+ if(ld->write_wakeup)
+ ld->write_wakeup(tty);
+ tty_ldisc_deref(ld);
+ }
+ }
+ wake_up_interruptible(&tty->write_wait);
+}
+
+EXPORT_SYMBOL_GPL(tty_wakeup);
+
+/**
+ * tty_ldisc_flush - flush line discipline queue
+ * @tty: tty
+ *
+ * Flush the line discipline queue (if any) for this tty. If there
+ * is no line discipline active this is a no-op.
+ */
+
+void tty_ldisc_flush(struct tty_struct *tty)
+{
+ struct tty_ldisc *ld = tty_ldisc_ref(tty);
+ if(ld) {
+ if(ld->flush_buffer)
+ ld->flush_buffer(tty);
+ tty_ldisc_deref(ld);
+ }
+}
+
+EXPORT_SYMBOL_GPL(tty_ldisc_flush);
+
+/*
+ * This can be called by the "eventd" kernel thread. That is process
synchronous,
+ * but doesn't hold any locks, so we need to make sure we have the appropriate
+ * locks for what we're doing..
+ */
+static void do_tty_hangup(void *data)
+{
+ struct tty_struct *tty = (struct tty_struct *) data;
+ struct file * cons_filp = NULL;
+ struct file *filp, *f = NULL;
+ struct task_struct *p;
+ struct tty_ldisc *ld;
+ int closecount = 0, n;
+
+ if (!tty)
+ return;
+
+ /* inuse_filps is protected by the single kernel lock */
+ lock_kernel();
+
+ spin_lock(&redirect_lock);
+ if (redirect && redirect->private_data == tty) {
+ f = redirect;
+ redirect = NULL;
+ }
+ spin_unlock(&redirect_lock);
+
+ check_tty_count(tty, "do_tty_hangup");
+ file_list_lock();
+ /* This breaks for file handles being sent over AF_UNIX sockets ? */
+ list_for_each_entry(filp, &tty->tty_files, f_u.fu_list) {
+ if (filp->f_op->write == redirected_tty_write)
+ cons_filp = filp;
+ if (filp->f_op->write != tty_write)
+ continue;
+ closecount++;
+ tty_fasync(-1, filp, 0); /* can't block */
+ filp->f_op = &hung_up_tty_fops;
+ }
+ file_list_unlock();
+
+ /* FIXME! What are the locking issues here? This may me overdoing
things..
+ * this question is especially important now that we've removed the
irqlock. */
+
+ ld = tty_ldisc_ref(tty);
+ if(ld != NULL) /* We may have no line discipline at this point */
+ {
+ if (ld->flush_buffer)
+ ld->flush_buffer(tty);
+ if (tty->driver->flush_buffer)
+ tty->driver->flush_buffer(tty);
+ if ((test_bit(TTY_DO_WRITE_WAKEUP, &tty->flags)) &&
+ ld->write_wakeup)
+ ld->write_wakeup(tty);
+ if (ld->hangup)
+ ld->hangup(tty);
+ }
+
+ /* FIXME: Once we trust the LDISC code better we can wait here for
+ ldisc completion and fix the driver call race */
+
+ wake_up_interruptible(&tty->write_wait);
+ wake_up_interruptible(&tty->read_wait);
+
+ /*
+ * Shutdown the current line discipline, and reset it to
+ * N_TTY.
+ */
+ if (tty->driver->flags & TTY_DRIVER_RESET_TERMIOS)
+ {
+ down(&tty->termios_sem);
+ *tty->termios = tty->driver->init_termios;
+ up(&tty->termios_sem);
+ }
+
+ /* Defer ldisc switch */
+ /* tty_deferred_ldisc_switch(N_TTY);
+
+ This should get done automatically when the port closes and
+ tty_release is called */
+
+ read_lock(&tasklist_lock);
+ if (tty->session > 0) {
+ do_each_task_pid(tty->session, PIDTYPE_SID, p) {
+ if (p->signal->tty == tty)
+ p->signal->tty = NULL;
+ if (!p->signal->leader)
+ continue;
+ send_group_sig_info(SIGHUP, SEND_SIG_PRIV, p);
+ send_group_sig_info(SIGCONT, SEND_SIG_PRIV, p);
+ if (tty->pgrp > 0)
+ p->signal->tty_old_pgrp = tty->pgrp;
+ } while_each_task_pid(tty->session, PIDTYPE_SID, p);
+ }
+ read_unlock(&tasklist_lock);
+
+ tty->flags = 0;
+ tty->session = 0;
+ tty->pgrp = -1;
+ tty->ctrl_status = 0;
+ /*
+ * If one of the devices matches a console pointer, we
+ * cannot just call hangup() because that will cause
+ * tty->count and state->count to go out of sync.
+ * So we just call close() the right number of times.
+ */
+ if (cons_filp) {
+ if (tty->driver->close)
+ for (n = 0; n < closecount; n++)
+ tty->driver->close(tty, cons_filp);
+ } else if (tty->driver->hangup)
+ (tty->driver->hangup)(tty);
+
+ /* We don't want to have driver/ldisc interactions beyond
+ the ones we did here. The driver layer expects no
+ calls after ->hangup() from the ldisc side. However we
+ can't yet guarantee all that */
+
+ set_bit(TTY_HUPPED, &tty->flags);
+ if (ld) {
+ tty_ldisc_enable(tty);
+ tty_ldisc_deref(ld);
+ }
+ unlock_kernel();
+ if (f)
+ fput(f);
+}
+
+void tty_hangup(struct tty_struct * tty)
+{
+#ifdef TTY_DEBUG_HANGUP
+ char buf[64];
+
+ printk(KERN_DEBUG "%s hangup...\n", tty_name(tty, buf));
+#endif
+ schedule_work(&tty->hangup_work);
+}
+
+EXPORT_SYMBOL(tty_hangup);
+
+void tty_vhangup(struct tty_struct * tty)
+{
+#ifdef TTY_DEBUG_HANGUP
+ char buf[64];
+
+ printk(KERN_DEBUG "%s vhangup...\n", tty_name(tty, buf));
+#endif
+ do_tty_hangup((void *) tty);
+}
+EXPORT_SYMBOL(tty_vhangup);
+
+int tty_hung_up_p(struct file * filp)
+{
+ return (filp->f_op == &hung_up_tty_fops);
+}
+
+EXPORT_SYMBOL(tty_hung_up_p);
+
+/*
+ * This function is typically called only by the session leader, when
+ * it wants to disassociate itself from its controlling tty.
+ *
+ * It performs the following functions:
+ * (1) Sends a SIGHUP and SIGCONT to the foreground process group
+ * (2) Clears the tty from being controlling the session
+ * (3) Clears the controlling tty for all processes in the
+ * session group.
+ *
+ * The argument on_exit is set to 1 if called when a process is
+ * exiting; it is 0 if called by the ioctl TIOCNOTTY.
+ */
+void disassociate_ctty(int on_exit)
+{
+ struct tty_struct *tty;
+ struct task_struct *p;
+ int tty_pgrp = -1;
+
+ lock_kernel();
+
+ down(&tty_sem);
+ tty = current->signal->tty;
+ if (tty) {
+ tty_pgrp = tty->pgrp;
+ up(&tty_sem);
+ if (on_exit && tty->driver->type != TTY_DRIVER_TYPE_PTY)
+ tty_vhangup(tty);
+ } else {
+ if (current->signal->tty_old_pgrp) {
+ kill_pg(current->signal->tty_old_pgrp, SIGHUP, on_exit);
+ kill_pg(current->signal->tty_old_pgrp, SIGCONT,
on_exit);
+ }
+ up(&tty_sem);
+ unlock_kernel();
+ return;
+ }
+ if (tty_pgrp > 0) {
+ kill_pg(tty_pgrp, SIGHUP, on_exit);
+ if (!on_exit)
+ kill_pg(tty_pgrp, SIGCONT, on_exit);
+ }
+
+ /* Must lock changes to tty_old_pgrp */
+ down(&tty_sem);
+ current->signal->tty_old_pgrp = 0;
+ tty->session = 0;
+ tty->pgrp = -1;
+
+ /* Now clear signal->tty under the lock */
+ read_lock(&tasklist_lock);
+ do_each_task_pid(current->signal->session, PIDTYPE_SID, p) {
+ p->signal->tty = NULL;
+ } while_each_task_pid(current->signal->session, PIDTYPE_SID, p);
+ read_unlock(&tasklist_lock);
+ up(&tty_sem);
+ unlock_kernel();
+}
+
+void stop_tty(struct tty_struct *tty)
+{
+ if (tty->stopped)
+ return;
+ tty->stopped = 1;
+ if (tty->link && tty->link->packet) {
+ tty->ctrl_status &= ~TIOCPKT_START;
+ tty->ctrl_status |= TIOCPKT_STOP;
+ wake_up_interruptible(&tty->link->read_wait);
+ }
+ if (tty->driver->stop)
+ (tty->driver->stop)(tty);
+}
+
+EXPORT_SYMBOL(stop_tty);
+
+void start_tty(struct tty_struct *tty)
+{
+ if (!tty->stopped || tty->flow_stopped)
+ return;
+ tty->stopped = 0;
+ if (tty->link && tty->link->packet) {
+ tty->ctrl_status &= ~TIOCPKT_STOP;
+ tty->ctrl_status |= TIOCPKT_START;
+ wake_up_interruptible(&tty->link->read_wait);
+ }
+ if (tty->driver->start)
+ (tty->driver->start)(tty);
+
+ /* If we have a running line discipline it may need kicking */
+ tty_wakeup(tty);
+ wake_up_interruptible(&tty->write_wait);
+}
+
+EXPORT_SYMBOL(start_tty);
+
+static ssize_t tty_read(struct file * file, char __user * buf, size_t count,
+ loff_t *ppos)
+{
+ int i;
+ struct tty_struct * tty;
+ struct inode *inode;
+ struct tty_ldisc *ld;
+
+ tty = (struct tty_struct *)file->private_data;
+ inode = file->f_dentry->d_inode;
+ if (tty_paranoia_check(tty, inode, "tty_read"))
+ return -EIO;
+ if (!tty || (test_bit(TTY_IO_ERROR, &tty->flags)))
+ return -EIO;
+
+ /* We want to wait for the line discipline to sort out in this
+ situation */
+ ld = tty_ldisc_ref_wait(tty);
+ lock_kernel();
+ if (ld->read)
+ i = (ld->read)(tty,file,buf,count);
+ else
+ i = -EIO;
+ tty_ldisc_deref(ld);
+ unlock_kernel();
+ if (i > 0)
+ inode->i_atime = current_fs_time(inode->i_sb);
+ return i;
+}
+
+/*
+ * Split writes up in sane blocksizes to avoid
+ * denial-of-service type attacks
+ */
+static inline ssize_t do_tty_write(
+ ssize_t (*write)(struct tty_struct *, struct file *, const unsigned
char *, size_t),
+ struct tty_struct *tty,
+ struct file *file,
+ const char __user *buf,
+ size_t count)
+{
+ ssize_t ret = 0, written = 0;
+ unsigned int chunk;
+
+ if (down_interruptible(&tty->atomic_write)) {
+ return -ERESTARTSYS;
+ }
+
+ /*
+ * We chunk up writes into a temporary buffer. This
+ * simplifies low-level drivers immensely, since they
+ * don't have locking issues and user mode accesses.
+ *
+ * But if TTY_NO_WRITE_SPLIT is set, we should use a
+ * big chunk-size..
+ *
+ * The default chunk-size is 2kB, because the NTTY
+ * layer has problems with bigger chunks. It will
+ * claim to be able to handle more characters than
+ * it actually does.
+ */
+ chunk = 2048;
+ if (test_bit(TTY_NO_WRITE_SPLIT, &tty->flags))
+ chunk = 65536;
+ if (count < chunk)
+ chunk = count;
+
+ /* write_buf/write_cnt is protected by the atomic_write semaphore */
+ if (tty->write_cnt < chunk) {
+ unsigned char *buf;
+
+ if (chunk < 1024)
+ chunk = 1024;
+
+ buf = kmalloc(chunk, GFP_KERNEL);
+ if (!buf) {
+ up(&tty->atomic_write);
+ return -ENOMEM;
+ }
+ kfree(tty->write_buf);
+ tty->write_cnt = chunk;
+ tty->write_buf = buf;
+ }
+
+ /* Do the write .. */
+ for (;;) {
+ size_t size = count;
+ if (size > chunk)
+ size = chunk;
+ ret = -EFAULT;
+ if (copy_from_user(tty->write_buf, buf, size))
+ break;
+ lock_kernel();
+ ret = write(tty, file, tty->write_buf, size);
+ unlock_kernel();
+ if (ret <= 0)
+ break;
+ written += ret;
+ buf += ret;
+ count -= ret;
+ if (!count)
+ break;
+ ret = -ERESTARTSYS;
+ if (signal_pending(current))
+ break;
+ cond_resched();
+ }
+ if (written) {
+ struct inode *inode = file->f_dentry->d_inode;
+ inode->i_mtime = current_fs_time(inode->i_sb);
+ ret = written;
+ }
+ up(&tty->atomic_write);
+ return ret;
+}
+
+
+static ssize_t tty_write(struct file * file, const char __user * buf, size_t
count,
+ loff_t *ppos)
+{
+ struct tty_struct * tty;
+ struct inode *inode = file->f_dentry->d_inode;
+ ssize_t ret;
+ struct tty_ldisc *ld;
+
+ tty = (struct tty_struct *)file->private_data;
+ if (tty_paranoia_check(tty, inode, "tty_write"))
+ return -EIO;
+ if (!tty || !tty->driver->write || (test_bit(TTY_IO_ERROR,
&tty->flags)))
+ return -EIO;
+
+ ld = tty_ldisc_ref_wait(tty);
+ if (!ld->write)
+ ret = -EIO;
+ else
+ ret = do_tty_write(ld->write, tty, file, buf, count);
+ tty_ldisc_deref(ld);
+ return ret;
+}
+
+ssize_t redirected_tty_write(struct file * file, const char __user * buf,
size_t count,
+ loff_t *ppos)
+{
+ struct file *p = NULL;
+
+ spin_lock(&redirect_lock);
+ if (redirect) {
+ get_file(redirect);
+ p = redirect;
+ }
+ spin_unlock(&redirect_lock);
+
+ if (p) {
+ ssize_t res;
+ res = vfs_write(p, buf, count, &p->f_pos);
+ fput(p);
+ return res;
+ }
+
+ return tty_write(file, buf, count, ppos);
+}
+
+static char ptychar[] = "pqrstuvwxyzabcde";
+
+static inline void pty_line_name(struct tty_driver *driver, int index, char *p)
+{
+ int i = index + driver->name_base;
+ /* ->name is initialized to "ttyp", but "tty" is expected */
+ sprintf(p, "%s%c%x",
+ driver->subtype == PTY_TYPE_SLAVE ? "tty" :
driver->name,
+ ptychar[i >> 4 & 0xf], i & 0xf);
+}
+
+static inline void tty_line_name(struct tty_driver *driver, int index, char *p)
+{
+ sprintf(p, "%s%d", driver->name, index + driver->name_base);
+}
+
+/*
+ * WSH 06/09/97: Rewritten to remove races and properly clean up after a
+ * failed open. The new code protects the open with a semaphore, so it's
+ * really quite straightforward. The semaphore locking can probably be
+ * relaxed for the (most common) case of reopening a tty.
+ */
+static int init_dev(struct tty_driver *driver, int idx,
+ struct tty_struct **ret_tty)
+{
+ struct tty_struct *tty, *o_tty;
+ struct termios *tp, **tp_loc, *o_tp, **o_tp_loc;
+ struct termios *ltp, **ltp_loc, *o_ltp, **o_ltp_loc;
+ int retval=0;
+
+ /* check whether we're reopening an existing tty */
+ if (driver->flags & TTY_DRIVER_DEVPTS_MEM) {
+ tty = devpts_get_tty(idx);
+ if (tty && driver->subtype == PTY_TYPE_MASTER)
+ tty = tty->link;
+ } else {
+ tty = driver->ttys[idx];
+ }
+ if (tty) goto fast_track;
+
+ /*
+ * First time open is complex, especially for PTY devices.
+ * This code guarantees that either everything succeeds and the
+ * TTY is ready for operation, or else the table slots are vacated
+ * and the allocated memory released. (Except that the termios
+ * and locked termios may be retained.)
+ */
+
+ if (!try_module_get(driver->owner)) {
+ retval = -ENODEV;
+ goto end_init;
+ }
+
+ o_tty = NULL;
+ tp = o_tp = NULL;
+ ltp = o_ltp = NULL;
+
+ tty = alloc_tty_struct();
+ if(!tty)
+ goto fail_no_mem;
+ initialize_tty_struct(tty);
+ tty->driver = driver;
+ tty->index = idx;
+ tty_line_name(driver, idx, tty->name);
+
+ if (driver->flags & TTY_DRIVER_DEVPTS_MEM) {
+ tp_loc = &tty->termios;
+ ltp_loc = &tty->termios_locked;
+ } else {
+ tp_loc = &driver->termios[idx];
+ ltp_loc = &driver->termios_locked[idx];
+ }
+
+ if (!*tp_loc) {
+ tp = (struct termios *) kmalloc(sizeof(struct termios),
+ GFP_KERNEL);
+ if (!tp)
+ goto free_mem_out;
+ *tp = driver->init_termios;
+ }
+
+ if (!*ltp_loc) {
+ ltp = (struct termios *) kmalloc(sizeof(struct termios),
+ GFP_KERNEL);
+ if (!ltp)
+ goto free_mem_out;
+ memset(ltp, 0, sizeof(struct termios));
+ }
+
+ if (driver->type == TTY_DRIVER_TYPE_PTY) {
+ o_tty = alloc_tty_struct();
+ if (!o_tty)
+ goto free_mem_out;
+ initialize_tty_struct(o_tty);
+ o_tty->driver = driver->other;
+ o_tty->index = idx;
+ tty_line_name(driver->other, idx, o_tty->name);
+
+ if (driver->flags & TTY_DRIVER_DEVPTS_MEM) {
+ o_tp_loc = &o_tty->termios;
+ o_ltp_loc = &o_tty->termios_locked;
+ } else {
+ o_tp_loc = &driver->other->termios[idx];
+ o_ltp_loc = &driver->other->termios_locked[idx];
+ }
+
+ if (!*o_tp_loc) {
+ o_tp = (struct termios *)
+ kmalloc(sizeof(struct termios), GFP_KERNEL);
+ if (!o_tp)
+ goto free_mem_out;
+ *o_tp = driver->other->init_termios;
+ }
+
+ if (!*o_ltp_loc) {
+ o_ltp = (struct termios *)
+ kmalloc(sizeof(struct termios), GFP_KERNEL);
+ if (!o_ltp)
+ goto free_mem_out;
+ memset(o_ltp, 0, sizeof(struct termios));
+ }
+
+ /*
+ * Everything allocated ... set up the o_tty structure.
+ */
+ if (!(driver->other->flags & TTY_DRIVER_DEVPTS_MEM)) {
+ driver->other->ttys[idx] = o_tty;
+ }
+ if (!*o_tp_loc)
+ *o_tp_loc = o_tp;
+ if (!*o_ltp_loc)
+ *o_ltp_loc = o_ltp;
+ o_tty->termios = *o_tp_loc;
+ o_tty->termios_locked = *o_ltp_loc;
+ driver->other->refcount++;
+ if (driver->subtype == PTY_TYPE_MASTER)
+ o_tty->count++;
+
+ /* Establish the links in both directions */
+ tty->link = o_tty;
+ o_tty->link = tty;
+ }
+
+ /*
+ * All structures have been allocated, so now we install them.
+ * Failures after this point use release_mem to clean up, so
+ * there's no need to null out the local pointers.
+ */
+ if (!(driver->flags & TTY_DRIVER_DEVPTS_MEM)) {
+ driver->ttys[idx] = tty;
+ }
+
+ if (!*tp_loc)
+ *tp_loc = tp;
+ if (!*ltp_loc)
+ *ltp_loc = ltp;
+ tty->termios = *tp_loc;
+ tty->termios_locked = *ltp_loc;
+ driver->refcount++;
+ tty->count++;
+
+ /*
+ * Structures all installed ... call the ldisc open routines.
+ * If we fail here just call release_mem to clean up. No need
+ * to decrement the use counts, as release_mem doesn't care.
+ */
+
+ if (tty->ldisc.open) {
+ retval = (tty->ldisc.open)(tty);
+ if (retval)
+ goto release_mem_out;
+ }
+ if (o_tty && o_tty->ldisc.open) {
+ retval = (o_tty->ldisc.open)(o_tty);
+ if (retval) {
+ if (tty->ldisc.close)
+ (tty->ldisc.close)(tty);
+ goto release_mem_out;
+ }
+ tty_ldisc_enable(o_tty);
+ }
+ tty_ldisc_enable(tty);
+ goto success;
+
+ /*
+ * This fast open can be used if the tty is already open.
+ * No memory is allocated, and the only failures are from
+ * attempting to open a closing tty or attempting multiple
+ * opens on a pty master.
+ */
+fast_track:
+ if (test_bit(TTY_CLOSING, &tty->flags)) {
+ retval = -EIO;
+ goto end_init;
+ }
+ if (driver->type == TTY_DRIVER_TYPE_PTY &&
+ driver->subtype == PTY_TYPE_MASTER) {
+ /*
+ * special case for PTY masters: only one open permitted,
+ * and the slave side open count is incremented as well.
+ */
+ if (tty->count) {
+ retval = -EIO;
+ goto end_init;
+ }
+ tty->link->count++;
+ }
+ tty->count++;
+ tty->driver = driver; /* N.B. why do this every time?? */
+
+ /* FIXME */
+ if(!test_bit(TTY_LDISC, &tty->flags))
+ printk(KERN_ERR "init_dev but no ldisc\n");
+success:
+ *ret_tty = tty;
+
+ /* All paths come through here to release the semaphore */
+end_init:
+ return retval;
+
+ /* Release locally allocated memory ... nothing placed in slots */
+free_mem_out:
+ kfree(o_tp);
+ if (o_tty)
+ free_tty_struct(o_tty);
+ kfree(ltp);
+ kfree(tp);
+ free_tty_struct(tty);
+
+fail_no_mem:
+ module_put(driver->owner);
+ retval = -ENOMEM;
+ goto end_init;
+
+ /* call the tty release_mem routine to clean out this slot */
+release_mem_out:
+ printk(KERN_INFO "init_dev: ldisc open failed, "
+ "clearing slot %d\n", idx);
+ release_mem(tty, idx);
+ goto end_init;
+}
+
+/*
+ * Releases memory associated with a tty structure, and clears out the
+ * driver table slots.
+ */
+static void release_mem(struct tty_struct *tty, int idx)
+{
+ struct tty_struct *o_tty;
+ struct termios *tp;
+ int devpts = tty->driver->flags & TTY_DRIVER_DEVPTS_MEM;
+
+ if ((o_tty = tty->link) != NULL) {
+ if (!devpts)
+ o_tty->driver->ttys[idx] = NULL;
+ if (o_tty->driver->flags & TTY_DRIVER_RESET_TERMIOS) {
+ tp = o_tty->termios;
+ if (!devpts)
+ o_tty->driver->termios[idx] = NULL;
+ kfree(tp);
+
+ tp = o_tty->termios_locked;
+ if (!devpts)
+ o_tty->driver->termios_locked[idx] = NULL;
+ kfree(tp);
+ }
+ o_tty->magic = 0;
+ o_tty->driver->refcount--;
+ file_list_lock();
+ list_del_init(&o_tty->tty_files);
+ file_list_unlock();
+ free_tty_struct(o_tty);
+ }
+
+ if (!devpts)
+ tty->driver->ttys[idx] = NULL;
+ if (tty->driver->flags & TTY_DRIVER_RESET_TERMIOS) {
+ tp = tty->termios;
+ if (!devpts)
+ tty->driver->termios[idx] = NULL;
+ kfree(tp);
+
+ tp = tty->termios_locked;
+ if (!devpts)
+ tty->driver->termios_locked[idx] = NULL;
+ kfree(tp);
+ }
+
+ tty->magic = 0;
+ tty->driver->refcount--;
+ file_list_lock();
+ list_del_init(&tty->tty_files);
+ file_list_unlock();
+ module_put(tty->driver->owner);
+ free_tty_struct(tty);
+}
+
+/*
+ * Even releasing the tty structures is a tricky business.. We have
+ * to be very careful that the structures are all released at the
+ * same time, as interrupts might otherwise get the wrong pointers.
+ *
+ * WSH 09/09/97: rewritten to avoid some nasty race conditions that could
+ * lead to double frees or releasing memory still in use.
+ */
+static void release_dev(struct file * filp)
+{
+ struct tty_struct *tty, *o_tty;
+ int pty_master, tty_closing, o_tty_closing, do_sleep;
+ int devpts_master, devpts;
+ int idx;
+ char buf[64];
+ unsigned long flags;
+
+ tty = (struct tty_struct *)filp->private_data;
+ if (tty_paranoia_check(tty, filp->f_dentry->d_inode, "release_dev"))
+ return;
+
+ check_tty_count(tty, "release_dev");
+
+ tty_fasync(-1, filp, 0);
+
+ idx = tty->index;
+ pty_master = (tty->driver->type == TTY_DRIVER_TYPE_PTY &&
+ tty->driver->subtype == PTY_TYPE_MASTER);
+ devpts = (tty->driver->flags & TTY_DRIVER_DEVPTS_MEM) != 0;
+ devpts_master = pty_master && devpts;
+ o_tty = tty->link;
+
+#ifdef TTY_PARANOIA_CHECK
+ if (idx < 0 || idx >= tty->driver->num) {
+ printk(KERN_DEBUG "release_dev: bad idx when trying to "
+ "free (%s)\n", tty->name);
+ return;
+ }
+ if (!(tty->driver->flags & TTY_DRIVER_DEVPTS_MEM)) {
+ if (tty != tty->driver->ttys[idx]) {
+ printk(KERN_DEBUG "release_dev: driver.table[%d] not
tty "
+ "for (%s)\n", idx, tty->name);
+ return;
+ }
+ if (tty->termios != tty->driver->termios[idx]) {
+ printk(KERN_DEBUG "release_dev: driver.termios[%d] not
termios "
+ "for (%s)\n",
+ idx, tty->name);
+ return;
+ }
+ if (tty->termios_locked != tty->driver->termios_locked[idx]) {
+ printk(KERN_DEBUG "release_dev:
driver.termios_locked[%d] not "
+ "termios_locked for (%s)\n",
+ idx, tty->name);
+ return;
+ }
+ }
+#endif
+
+#ifdef TTY_DEBUG_HANGUP
+ printk(KERN_DEBUG "release_dev of %s (tty count=%d)...",
+ tty_name(tty, buf), tty->count);
+#endif
+
+#ifdef TTY_PARANOIA_CHECK
+ if (tty->driver->other &&
+ !(tty->driver->flags & TTY_DRIVER_DEVPTS_MEM)) {
+ if (o_tty != tty->driver->other->ttys[idx]) {
+ printk(KERN_DEBUG "release_dev: other->table[%d] "
+ "not o_tty for (%s)\n",
+ idx, tty->name);
+ return;
+ }
+ if (o_tty->termios != tty->driver->other->termios[idx]) {
+ printk(KERN_DEBUG "release_dev: other->termios[%d] "
+ "not o_termios for (%s)\n",
+ idx, tty->name);
+ return;
+ }
+ if (o_tty->termios_locked !=
+ tty->driver->other->termios_locked[idx]) {
+ printk(KERN_DEBUG "release_dev: other->termios_locked["
+ "%d] not o_termios_locked for (%s)\n",
+ idx, tty->name);
+ return;
+ }
+ if (o_tty->link != tty) {
+ printk(KERN_DEBUG "release_dev: bad pty pointers\n");
+ return;
+ }
+ }
+#endif
+ if (tty->driver->close)
+ tty->driver->close(tty, filp);
+
+ /*
+ * Sanity check: if tty->count is going to zero, there shouldn't be
+ * any waiters on tty->read_wait or tty->write_wait. We test the
+ * wait queues and kick everyone out _before_ actually starting to
+ * close. This ensures that we won't block while releasing the tty
+ * structure.
+ *
+ * The test for the o_tty closing is necessary, since the master and
+ * slave sides may close in any order. If the slave side closes out
+ * first, its count will be one, since the master side holds an open.
+ * Thus this test wouldn't be triggered at the time the slave closes,
+ * so we do it now.
+ *
+ * Note that it's possible for the tty to be opened again while we're
+ * flushing out waiters. By recalculating the closing flags before
+ * each iteration we avoid any problems.
+ */
+ while (1) {
+ /* Guard against races with tty->count changes elsewhere and
+ opens on /dev/tty */
+
+ down(&tty_sem);
+ tty_closing = tty->count <= 1;
+ o_tty_closing = o_tty &&
+ (o_tty->count <= (pty_master ? 1 : 0));
+ do_sleep = 0;
+
+ if (tty_closing) {
+ if (waitqueue_active(&tty->read_wait)) {
+ wake_up(&tty->read_wait);
+ do_sleep++;
+ }
+ if (waitqueue_active(&tty->write_wait)) {
+ wake_up(&tty->write_wait);
+ do_sleep++;
+ }
+ }
+ if (o_tty_closing) {
+ if (waitqueue_active(&o_tty->read_wait)) {
+ wake_up(&o_tty->read_wait);
+ do_sleep++;
+ }
+ if (waitqueue_active(&o_tty->write_wait)) {
+ wake_up(&o_tty->write_wait);
+ do_sleep++;
+ }
+ }
+ if (!do_sleep)
+ break;
+
+ printk(KERN_WARNING "release_dev: %s: read/write wait queue "
+ "active!\n", tty_name(tty, buf));
+ up(&tty_sem);
+ schedule();
+ }
+
+ /*
+ * The closing flags are now consistent with the open counts on
+ * both sides, and we've completed the last operation that could
+ * block, so it's safe to proceed with closing.
+ */
+ if (pty_master) {
+ if (--o_tty->count < 0) {
+ printk(KERN_WARNING "release_dev: bad pty slave count "
+ "(%d) for %s\n",
+ o_tty->count, tty_name(o_tty, buf));
+ o_tty->count = 0;
+ }
+ }
+ if (--tty->count < 0) {
+ printk(KERN_WARNING "release_dev: bad tty->count (%d) for %s\n",
+ tty->count, tty_name(tty, buf));
+ tty->count = 0;
+ }
+
+ /*
+ * We've decremented tty->count, so we need to remove this file
+ * descriptor off the tty->tty_files list; this serves two
+ * purposes:
+ * - check_tty_count sees the correct number of file descriptors
+ * associated with this tty.
+ * - do_tty_hangup no longer sees this file descriptor as
+ * something that needs to be handled for hangups.
+ */
+ file_kill(filp);
+ filp->private_data = NULL;
+
+ /*
+ * Perform some housekeeping before deciding whether to return.
+ *
+ * Set the TTY_CLOSING flag if this was the last open. In the
+ * case of a pty we may have to wait around for the other side
+ * to close, and TTY_CLOSING makes sure we can't be reopened.
+ */
+ if(tty_closing)
+ set_bit(TTY_CLOSING, &tty->flags);
+ if(o_tty_closing)
+ set_bit(TTY_CLOSING, &o_tty->flags);
+
+ /*
+ * If _either_ side is closing, make sure there aren't any
+ * processes that still think tty or o_tty is their controlling
+ * tty.
+ */
+ if (tty_closing || o_tty_closing) {
+ struct task_struct *p;
+
+ read_lock(&tasklist_lock);
+ do_each_task_pid(tty->session, PIDTYPE_SID, p) {
+ p->signal->tty = NULL;
+ } while_each_task_pid(tty->session, PIDTYPE_SID, p);
+ if (o_tty)
+ do_each_task_pid(o_tty->session, PIDTYPE_SID, p) {
+ p->signal->tty = NULL;
+ } while_each_task_pid(o_tty->session, PIDTYPE_SID, p);
+ read_unlock(&tasklist_lock);
+ }
+
+ up(&tty_sem);
+
+ /* check whether both sides are closing ... */
+ if (!tty_closing || (o_tty && !o_tty_closing))
+ return;
+
+#ifdef TTY_DEBUG_HANGUP
+ printk(KERN_DEBUG "freeing tty structure...");
+#endif
+ /*
+ * Prevent flush_to_ldisc() from rescheduling the work for later. Then
+ * kill any delayed work. As this is the final close it does not
+ * race with the set_ldisc code path.
+ */
+ clear_bit(TTY_LDISC, &tty->flags);
+ clear_bit(TTY_DONT_FLIP, &tty->flags);
+ cancel_delayed_work(&tty->buf.work);
+
+ /*
+ * Wait for ->hangup_work and ->buf.work handlers to terminate
+ */
+
+ flush_scheduled_work();
+
+ /*
+ * Wait for any short term users (we know they are just driver
+ * side waiters as the file is closing so user count on the file
+ * side is zero.
+ */
+ spin_lock_irqsave(&tty_ldisc_lock, flags);
+ while(tty->ldisc.refcount)
+ {
+ spin_unlock_irqrestore(&tty_ldisc_lock, flags);
+ wait_event(tty_ldisc_wait, tty->ldisc.refcount == 0);
+ spin_lock_irqsave(&tty_ldisc_lock, flags);
+ }
+ spin_unlock_irqrestore(&tty_ldisc_lock, flags);
+ /*
+ * Shutdown the current line discipline, and reset it to N_TTY.
+ * N.B. why reset ldisc when we're releasing the memory??
+ *
+ * FIXME: this MUST get fixed for the new reflocking
+ */
+ if (tty->ldisc.close)
+ (tty->ldisc.close)(tty);
+ tty_ldisc_put(tty->ldisc.num);
+
+ /*
+ * Switch the line discipline back
+ */
+ tty_ldisc_assign(tty, tty_ldisc_get(N_TTY));
+ tty_set_termios_ldisc(tty,N_TTY);
+ if (o_tty) {
+ /* FIXME: could o_tty be in setldisc here ? */
+ clear_bit(TTY_LDISC, &o_tty->flags);
+ if (o_tty->ldisc.close)
+ (o_tty->ldisc.close)(o_tty);
+ tty_ldisc_put(o_tty->ldisc.num);
+ tty_ldisc_assign(o_tty, tty_ldisc_get(N_TTY));
+ tty_set_termios_ldisc(o_tty,N_TTY);
+ }
+ /*
+ * The release_mem function takes care of the details of clearing
+ * the slots and preserving the termios structure.
+ */
+ release_mem(tty, idx);
+
+#ifdef CONFIG_UNIX98_PTYS
+ /* Make this pty number available for reallocation */
+ if (devpts) {
+ down(&allocated_ptys_lock);
+ idr_remove(&allocated_ptys, idx);
+ up(&allocated_ptys_lock);
+ }
+#endif
+
+}
+
+/*
+ * tty_open and tty_release keep up the tty count that contains the
+ * number of opens done on a tty. We cannot use the inode-count, as
+ * different inodes might point to the same tty.
+ *
+ * Open-counting is needed for pty masters, as well as for keeping
+ * track of serial lines: DTR is dropped when the last close happens.
+ * (This is not done solely through tty->count, now. - Ted 1/27/92)
+ *
+ * The termios state of a pty is reset on first open so that
+ * settings don't persist across reuse.
+ */
+static int tty_open(struct inode * inode, struct file * filp)
+{
+ struct tty_struct *tty;
+ int noctty, retval;
+ struct tty_driver *driver;
+ int index;
+ dev_t device = inode->i_rdev;
+ unsigned short saved_flags = filp->f_flags;
+
+ nonseekable_open(inode, filp);
+
+retry_open:
+ noctty = filp->f_flags & O_NOCTTY;
+ index = -1;
+ retval = 0;
+
+ down(&tty_sem);
+
+ if (device == MKDEV(TTYAUX_MAJOR,0)) {
+ if (!current->signal->tty) {
+ up(&tty_sem);
+ return -ENXIO;
+ }
+ driver = current->signal->tty->driver;
+ index = current->signal->tty->index;
+ filp->f_flags |= O_NONBLOCK; /* Don't let /dev/tty block */
+ /* noctty = 1; */
+ goto got_driver;
+ }
+#ifdef CONFIG_VT
+ if (console_use_vt && (device == MKDEV(TTY_MAJOR,0))) {
+ extern struct tty_driver *console_driver;
+ driver = console_driver;
+ index = fg_console;
+ noctty = 1;
+ goto got_driver;
+ }
+#endif
+ if (device == MKDEV(TTYAUX_MAJOR,1)) {
+ driver = console_device(&index);
+ if (driver) {
+ /* Don't let /dev/console block */
+ filp->f_flags |= O_NONBLOCK;
+ noctty = 1;
+ goto got_driver;
+ }
+ up(&tty_sem);
+ return -ENODEV;
+ }
+
+ driver = get_tty_driver(device, &index);
+ if (!driver) {
+ up(&tty_sem);
+ return -ENODEV;
+ }
+got_driver:
+ retval = init_dev(driver, index, &tty);
+ up(&tty_sem);
+ if (retval)
+ return retval;
+
+ filp->private_data = tty;
+ file_move(filp, &tty->tty_files);
+ check_tty_count(tty, "tty_open");
+ if (tty->driver->type == TTY_DRIVER_TYPE_PTY &&
+ tty->driver->subtype == PTY_TYPE_MASTER)
+ noctty = 1;
+#ifdef TTY_DEBUG_HANGUP
+ printk(KERN_DEBUG "opening %s...", tty->name);
+#endif
+ if (!retval) {
+ if (tty->driver->open)
+ retval = tty->driver->open(tty, filp);
+ else
+ retval = -ENODEV;
+ }
+ filp->f_flags = saved_flags;
+
+ if (!retval && test_bit(TTY_EXCLUSIVE, &tty->flags) &&
!capable(CAP_SYS_ADMIN))
+ retval = -EBUSY;
+
+ if (retval) {
+#ifdef TTY_DEBUG_HANGUP
+ printk(KERN_DEBUG "error %d in opening %s...", retval,
+ tty->name);
+#endif
+ release_dev(filp);
+ if (retval != -ERESTARTSYS)
+ return retval;
+ if (signal_pending(current))
+ return retval;
+ schedule();
+ /*
+ * Need to reset f_op in case a hangup happened.
+ */
+ if (filp->f_op == &hung_up_tty_fops)
+ filp->f_op = &tty_fops;
+ goto retry_open;
+ }
+ if (!noctty &&
+ current->signal->leader &&
+ !current->signal->tty &&
+ tty->session == 0) {
+ task_lock(current);
+ current->signal->tty = tty;
+ task_unlock(current);
+ current->signal->tty_old_pgrp = 0;
+ tty->session = current->signal->session;
+ tty->pgrp = process_group(current);
+ }
+ return 0;
+}
+
+#ifdef CONFIG_UNIX98_PTYS
+static int ptmx_open(struct inode * inode, struct file * filp)
+{
+ struct tty_struct *tty;
+ int retval;
+ int index;
+ int idr_ret;
+
+ nonseekable_open(inode, filp);
+
+ /* find a device that is not in use. */
+ down(&allocated_ptys_lock);
+ if (!idr_pre_get(&allocated_ptys, GFP_KERNEL)) {
+ up(&allocated_ptys_lock);
+ return -ENOMEM;
+ }
+ idr_ret = idr_get_new(&allocated_ptys, NULL, &index);
+ if (idr_ret < 0) {
+ up(&allocated_ptys_lock);
+ if (idr_ret == -EAGAIN)
+ return -ENOMEM;
+ return -EIO;
+ }
+ if (index >= pty_limit) {
+ idr_remove(&allocated_ptys, index);
+ up(&allocated_ptys_lock);
+ return -EIO;
+ }
+ up(&allocated_ptys_lock);
+
+ down(&tty_sem);
+ retval = init_dev(ptm_driver, index, &tty);
+ up(&tty_sem);
+
+ if (retval)
+ goto out;
+
+ set_bit(TTY_PTY_LOCK, &tty->flags); /* LOCK THE SLAVE */
+ filp->private_data = tty;
+ file_move(filp, &tty->tty_files);
+
+ retval = -ENOMEM;
+ if (devpts_pty_new(tty->link))
+ goto out1;
+
+ check_tty_count(tty, "tty_open");
+ retval = ptm_driver->open(tty, filp);
+ if (!retval)
+ return 0;
+out1:
+ release_dev(filp);
+out:
+ down(&allocated_ptys_lock);
+ idr_remove(&allocated_ptys, index);
+ up(&allocated_ptys_lock);
+ return retval;
+}
+#endif
+
+static int tty_release(struct inode * inode, struct file * filp)
+{
+ lock_kernel();
+ release_dev(filp);
+ unlock_kernel();
+ return 0;
+}
+
+/* No kernel lock held - fine */
+static unsigned int tty_poll(struct file * filp, poll_table * wait)
+{
+ struct tty_struct * tty;
+ struct tty_ldisc *ld;
+ int ret = 0;
+
+ tty = (struct tty_struct *)filp->private_data;
+ if (tty_paranoia_check(tty, filp->f_dentry->d_inode, "tty_poll"))
+ return 0;
+
+ ld = tty_ldisc_ref_wait(tty);
+ if (ld->poll)
+ ret = (ld->poll)(tty, filp, wait);
+ tty_ldisc_deref(ld);
+ return ret;
+}
+
+static int tty_fasync(int fd, struct file * filp, int on)
+{
+ struct tty_struct * tty;
+ int retval;
+
+ tty = (struct tty_struct *)filp->private_data;
+ if (tty_paranoia_check(tty, filp->f_dentry->d_inode, "tty_fasync"))
+ return 0;
+
+ retval = fasync_helper(fd, filp, on, &tty->fasync);
+ if (retval <= 0)
+ return retval;
+
+ if (on) {
+ if (!waitqueue_active(&tty->read_wait))
+ tty->minimum_to_wake = 1;
+ retval = f_setown(filp, (-tty->pgrp) ? : current->pid, 0);
+ if (retval)
+ return retval;
+ } else {
+ if (!tty->fasync && !waitqueue_active(&tty->read_wait))
+ tty->minimum_to_wake = N_TTY_BUF_SIZE;
+ }
+ return 0;
+}
+
+static int tiocsti(struct tty_struct *tty, char __user *p)
+{
+ char ch, mbz = 0;
+ struct tty_ldisc *ld;
+
+ if ((current->signal->tty != tty) && !capable(CAP_SYS_ADMIN))
+ return -EPERM;
+ if (get_user(ch, p))
+ return -EFAULT;
+ ld = tty_ldisc_ref_wait(tty);
+ ld->receive_buf(tty, &ch, &mbz, 1);
+ tty_ldisc_deref(ld);
+ return 0;
+}
+
+static int tiocgwinsz(struct tty_struct *tty, struct winsize __user * arg)
+{
+ if (copy_to_user(arg, &tty->winsize, sizeof(*arg)))
+ return -EFAULT;
+ return 0;
+}
+
+static int tiocswinsz(struct tty_struct *tty, struct tty_struct *real_tty,
+ struct winsize __user * arg)
+{
+ struct winsize tmp_ws;
+
+ if (copy_from_user(&tmp_ws, arg, sizeof(*arg)))
+ return -EFAULT;
+ if (!memcmp(&tmp_ws, &tty->winsize, sizeof(*arg)))
+ return 0;
+#ifdef CONFIG_VT
+ if (tty->driver->type == TTY_DRIVER_TYPE_CONSOLE) {
+ int rc;
+
+ acquire_console_sem();
+ rc = vc_resize(tty->driver_data, tmp_ws.ws_col, tmp_ws.ws_row);
+ release_console_sem();
+ if (rc)
+ return -ENXIO;
+ }
+#endif
+ if (tty->pgrp > 0)
+ kill_pg(tty->pgrp, SIGWINCH, 1);
+ if ((real_tty->pgrp != tty->pgrp) && (real_tty->pgrp > 0))
+ kill_pg(real_tty->pgrp, SIGWINCH, 1);
+ tty->winsize = tmp_ws;
+ real_tty->winsize = tmp_ws;
+ return 0;
+}
+
+static int tioccons(struct file *file)
+{
+ if (!capable(CAP_SYS_ADMIN))
+ return -EPERM;
+ if (file->f_op->write == redirected_tty_write) {
+ struct file *f;
+ spin_lock(&redirect_lock);
+ f = redirect;
+ redirect = NULL;
+ spin_unlock(&redirect_lock);
+ if (f)
+ fput(f);
+ return 0;
+ }
+ spin_lock(&redirect_lock);
+ if (redirect) {
+ spin_unlock(&redirect_lock);
+ return -EBUSY;
+ }
+ get_file(file);
+ redirect = file;
+ spin_unlock(&redirect_lock);
+ return 0;
+}
+
+
+static int fionbio(struct file *file, int __user *p)
+{
+ int nonblock;
+
+ if (get_user(nonblock, p))
+ return -EFAULT;
+
+ if (nonblock)
+ file->f_flags |= O_NONBLOCK;
+ else
+ file->f_flags &= ~O_NONBLOCK;
+ return 0;
+}
+
+static int tiocsctty(struct tty_struct *tty, int arg)
+{
+ task_t *p;
+
+ if (current->signal->leader &&
+ (current->signal->session == tty->session))
+ return 0;
+ /*
+ * The process must be a session leader and
+ * not have a controlling tty already.
+ */
+ if (!current->signal->leader || current->signal->tty)
+ return -EPERM;
+ if (tty->session > 0) {
+ /*
+ * This tty is already the controlling
+ * tty for another session group!
+ */
+ if ((arg == 1) && capable(CAP_SYS_ADMIN)) {
+ /*
+ * Steal it away
+ */
+
+ read_lock(&tasklist_lock);
+ do_each_task_pid(tty->session, PIDTYPE_SID, p) {
+ p->signal->tty = NULL;
+ } while_each_task_pid(tty->session, PIDTYPE_SID, p);
+ read_unlock(&tasklist_lock);
+ } else
+ return -EPERM;
+ }
+ task_lock(current);
+ current->signal->tty = tty;
+ task_unlock(current);
+ current->signal->tty_old_pgrp = 0;
+ tty->session = current->signal->session;
+ tty->pgrp = process_group(current);
+ return 0;
+}
+
+static int tiocgpgrp(struct tty_struct *tty, struct tty_struct *real_tty,
pid_t __user *p)
+{
+ /*
+ * (tty == real_tty) is a cheap way of
+ * testing if the tty is NOT a master pty.
+ */
+ if (tty == real_tty && current->signal->tty != real_tty)
+ return -ENOTTY;
+ return put_user(real_tty->pgrp, p);
+}
+
+static int tiocspgrp(struct tty_struct *tty, struct tty_struct *real_tty,
pid_t __user *p)
+{
+ pid_t pgrp;
+ int retval = tty_check_change(real_tty);
+
+ if (retval == -EIO)
+ return -ENOTTY;
+ if (retval)
+ return retval;
+ if (!current->signal->tty ||
+ (current->signal->tty != real_tty) ||
+ (real_tty->session != current->signal->session))
+ return -ENOTTY;
+ if (get_user(pgrp, p))
+ return -EFAULT;
+ if (pgrp < 0)
+ return -EINVAL;
+ if (session_of_pgrp(pgrp) != current->signal->session)
+ return -EPERM;
+ real_tty->pgrp = pgrp;
+ return 0;
+}
+
+static int tiocgsid(struct tty_struct *tty, struct tty_struct *real_tty, pid_t
__user *p)
+{
+ /*
+ * (tty == real_tty) is a cheap way of
+ * testing if the tty is NOT a master pty.
+ */
+ if (tty == real_tty && current->signal->tty != real_tty)
+ return -ENOTTY;
+ if (real_tty->session <= 0)
+ return -ENOTTY;
+ return put_user(real_tty->session, p);
+}
+
+static int tiocsetd(struct tty_struct *tty, int __user *p)
+{
+ int ldisc;
+
+ if (get_user(ldisc, p))
+ return -EFAULT;
+ return tty_set_ldisc(tty, ldisc);
+}
+
+static int send_break(struct tty_struct *tty, unsigned int duration)
+{
+ tty->driver->break_ctl(tty, -1);
+ if (!signal_pending(current)) {
+ msleep_interruptible(duration);
+ }
+ tty->driver->break_ctl(tty, 0);
+ if (signal_pending(current))
+ return -EINTR;
+ return 0;
+}
+
+static int
+tty_tiocmget(struct tty_struct *tty, struct file *file, int __user *p)
+{
+ int retval = -EINVAL;
+
+ if (tty->driver->tiocmget) {
+ retval = tty->driver->tiocmget(tty, file);
+
+ if (retval >= 0)
+ retval = put_user(retval, p);
+ }
+ return retval;
+}
+
+static int
+tty_tiocmset(struct tty_struct *tty, struct file *file, unsigned int cmd,
+ unsigned __user *p)
+{
+ int retval = -EINVAL;
+
+ if (tty->driver->tiocmset) {
+ unsigned int set, clear, val;
+
+ retval = get_user(val, p);
+ if (retval)
+ return retval;
+
+ set = clear = 0;
+ switch (cmd) {
+ case TIOCMBIS:
+ set = val;
+ break;
+ case TIOCMBIC:
+ clear = val;
+ break;
+ case TIOCMSET:
+ set = val;
+ clear = ~val;
+ break;
+ }
+
+ set &= TIOCM_DTR|TIOCM_RTS|TIOCM_OUT1|TIOCM_OUT2|TIOCM_LOOP;
+ clear &= TIOCM_DTR|TIOCM_RTS|TIOCM_OUT1|TIOCM_OUT2|TIOCM_LOOP;
+
+ retval = tty->driver->tiocmset(tty, file, set, clear);
+ }
+ return retval;
+}
+
+/*
+ * Split this up, as gcc can choke on it otherwise..
+ */
+int tty_ioctl(struct inode * inode, struct file * file,
+ unsigned int cmd, unsigned long arg)
+{
+ struct tty_struct *tty, *real_tty;
+ void __user *p = (void __user *)arg;
+ int retval;
+ struct tty_ldisc *ld;
+
+ tty = (struct tty_struct *)file->private_data;
+ if (tty_paranoia_check(tty, inode, "tty_ioctl"))
+ return -EINVAL;
+
+ real_tty = tty;
+ if (tty->driver->type == TTY_DRIVER_TYPE_PTY &&
+ tty->driver->subtype == PTY_TYPE_MASTER)
+ real_tty = tty->link;
+
+ /*
+ * Break handling by driver
+ */
+ if (!tty->driver->break_ctl) {
+ switch(cmd) {
+ case TIOCSBRK:
+ case TIOCCBRK:
+ if (tty->driver->ioctl)
+ return tty->driver->ioctl(tty, file, cmd, arg);
+ return -EINVAL;
+
+ /* These two ioctl's always return success; even if */
+ /* the driver doesn't support them. */
+ case TCSBRK:
+ case TCSBRKP:
+ if (!tty->driver->ioctl)
+ return 0;
+ retval = tty->driver->ioctl(tty, file, cmd, arg);
+ if (retval == -ENOIOCTLCMD)
+ retval = 0;
+ return retval;
+ }
+ }
+
+ /*
+ * Factor out some common prep work
+ */
+ switch (cmd) {
+ case TIOCSETD:
+ case TIOCSBRK:
+ case TIOCCBRK:
+ case TCSBRK:
+ case TCSBRKP:
+ retval = tty_check_change(tty);
+ if (retval)
+ return retval;
+ if (cmd != TIOCCBRK) {
+ tty_wait_until_sent(tty, 0);
+ if (signal_pending(current))
+ return -EINTR;
+ }
+ break;
+ }
+
+ switch (cmd) {
+ case TIOCSTI:
+ return tiocsti(tty, p);
+ case TIOCGWINSZ:
+ return tiocgwinsz(tty, p);
+ case TIOCSWINSZ:
+ return tiocswinsz(tty, real_tty, p);
+ case TIOCCONS:
+ return real_tty!=tty ? -EINVAL : tioccons(file);
+ case FIONBIO:
+ return fionbio(file, p);
+ case TIOCEXCL:
+ set_bit(TTY_EXCLUSIVE, &tty->flags);
+ return 0;
+ case TIOCNXCL:
+ clear_bit(TTY_EXCLUSIVE, &tty->flags);
+ return 0;
+ case TIOCNOTTY:
+ if (current->signal->tty != tty)
+ return -ENOTTY;
+ if (current->signal->leader)
+ disassociate_ctty(0);
+ task_lock(current);
+ current->signal->tty = NULL;
+ task_unlock(current);
+ return 0;
+ case TIOCSCTTY:
+ return tiocsctty(tty, arg);
+ case TIOCGPGRP:
+ return tiocgpgrp(tty, real_tty, p);
+ case TIOCSPGRP:
+ return tiocspgrp(tty, real_tty, p);
+ case TIOCGSID:
+ return tiocgsid(tty, real_tty, p);
+ case TIOCGETD:
+ /* FIXME: check this is ok */
+ return put_user(tty->ldisc.num, (int __user *)p);
+ case TIOCSETD:
+ return tiocsetd(tty, p);
+#ifdef CONFIG_VT
+ case TIOCLINUX:
+ return tioclinux(tty, arg);
+#endif
+ /*
+ * Break handling
+ */
+ case TIOCSBRK: /* Turn break on, unconditionally */
+ tty->driver->break_ctl(tty, -1);
+ return 0;
+
+ case TIOCCBRK: /* Turn break off, unconditionally */
+ tty->driver->break_ctl(tty, 0);
+ return 0;
+ case TCSBRK: /* SVID version: non-zero arg --> no break */
+ /*
+ * XXX is the above comment correct, or the
+ * code below correct? Is this ioctl used at
+ * all by anyone?
+ */
+ if (!arg)
+ return send_break(tty, 250);
+ return 0;
+ case TCSBRKP: /* support for POSIX tcsendbreak() */
+ return send_break(tty, arg ? arg*100 : 250);
+
+ case TIOCMGET:
+ return tty_tiocmget(tty, file, p);
+
+ case TIOCMSET:
+ case TIOCMBIC:
+ case TIOCMBIS:
+ return tty_tiocmset(tty, file, cmd, p);
+ }
+ if (tty->driver->ioctl) {
+ retval = (tty->driver->ioctl)(tty, file, cmd, arg);
+ if (retval != -ENOIOCTLCMD)
+ return retval;
+ }
+ ld = tty_ldisc_ref_wait(tty);
+ retval = -EINVAL;
+ if (ld->ioctl) {
+ retval = ld->ioctl(tty, file, cmd, arg);
+ if (retval == -ENOIOCTLCMD)
+ retval = -EINVAL;
+ }
+ tty_ldisc_deref(ld);
+ return retval;
+}
+
+
+/*
+ * This implements the "Secure Attention Key" --- the idea is to
+ * prevent trojan horses by killing all processes associated with this
+ * tty when the user hits the "Secure Attention Key". Required for
+ * super-paranoid applications --- see the Orange Book for more details.
+ *
+ * This code could be nicer; ideally it should send a HUP, wait a few
+ * seconds, then send a INT, and then a KILL signal. But you then
+ * have to coordinate with the init process, since all processes associated
+ * with the current tty must be dead before the new getty is allowed
+ * to spawn.
+ *
+ * Now, if it would be correct ;-/ The current code has a nasty hole -
+ * it doesn't catch files in flight. We may send the descriptor to ourselves
+ * via AF_UNIX socket, close it and later fetch from socket. FIXME.
+ *
+ * Nasty bug: do_SAK is being called in interrupt context. This can
+ * deadlock. We punt it up to process context. AKPM - 16Mar2001
+ */
+static void __do_SAK(void *arg)
+{
+#ifdef TTY_SOFT_SAK
+ tty_hangup(tty);
+#else
+ struct tty_struct *tty = arg;
+ struct task_struct *p;
+ int session;
+ int i;
+ struct file *filp;
+ struct tty_ldisc *disc;
+ struct fdtable *fdt;
+
+ if (!tty)
+ return;
+ session = tty->session;
+
+ /* We don't want an ldisc switch during this */
+ disc = tty_ldisc_ref(tty);
+ if (disc && disc->flush_buffer)
+ disc->flush_buffer(tty);
+ tty_ldisc_deref(disc);
+
+ if (tty->driver->flush_buffer)
+ tty->driver->flush_buffer(tty);
+
+ read_lock(&tasklist_lock);
+ do_each_task_pid(session, PIDTYPE_SID, p) {
+ if (p->signal->tty == tty || session > 0) {
+ printk(KERN_NOTICE "SAK: killed process %d"
+ " (%s): p->signal->session==tty->session\n",
+ p->pid, p->comm);
+ send_sig(SIGKILL, p, 1);
+ continue;
+ }
+ task_lock(p);
+ if (p->files) {
+ /*
+ * We don't take a ref to the file, so we must
+ * hold ->file_lock instead.
+ */
+ spin_lock(&p->files->file_lock);
+ fdt = files_fdtable(p->files);
+ for (i=0; i < fdt->max_fds; i++) {
+ filp = fcheck_files(p->files, i);
+ if (!filp)
+ continue;
+ if (filp->f_op->read == tty_read &&
+ filp->private_data == tty) {
+ printk(KERN_NOTICE "SAK: killed process
%d"
+ " (%s): fd#%d opened to the tty\n",
+ p->pid, p->comm, i);
+ send_sig(SIGKILL, p, 1);
+ break;
+ }
+ }
+ spin_unlock(&p->files->file_lock);
+ }
+ task_unlock(p);
+ } while_each_task_pid(session, PIDTYPE_SID, p);
+ read_unlock(&tasklist_lock);
+#endif
+}
+
+/*
+ * The tq handling here is a little racy - tty->SAK_work may already be queued.
+ * Fortunately we don't need to worry, because if ->SAK_work is already queued,
+ * the values which we write to it will be identical to the values which it
+ * already has. --akpm
+ */
+void do_SAK(struct tty_struct *tty)
+{
+ if (!tty)
+ return;
+ PREPARE_WORK(&tty->SAK_work, __do_SAK, tty);
+ schedule_work(&tty->SAK_work);
+}
+
+EXPORT_SYMBOL(do_SAK);
+
+/*
+ * This routine is called out of the software interrupt to flush data
+ * from the buffer chain to the line discipline.
+ */
+
+static void flush_to_ldisc(void *private_)
+{
+ struct tty_struct *tty = (struct tty_struct *) private_;
+ unsigned long flags;
+ struct tty_ldisc *disc;
+ struct tty_buffer *tbuf, *head;
+ int count;
+ char *char_buf;
+ unsigned char *flag_buf;
+
+ disc = tty_ldisc_ref(tty);
+ if (disc == NULL) /* !TTY_LDISC */
+ return;
+
+ if (test_bit(TTY_DONT_FLIP, &tty->flags)) {
+ /*
+ * Do it after the next timer tick:
+ */
+ schedule_delayed_work(&tty->buf.work, 1);
+ goto out;
+ }
+ spin_lock_irqsave(&tty->buf.lock, flags);
+ head = tty->buf.head;
+ tty->buf.head = NULL;
+ while((tbuf = head) != NULL) {
+ while ((count = tbuf->commit - tbuf->read) != 0) {
+ char_buf = tbuf->char_buf_ptr + tbuf->read;
+ flag_buf = tbuf->flag_buf_ptr + tbuf->read;
+ tbuf->read += count;
+ spin_unlock_irqrestore(&tty->buf.lock, flags);
+ disc->receive_buf(tty, char_buf, flag_buf, count);
+ spin_lock_irqsave(&tty->buf.lock, flags);
+ }
+ if (tbuf->active) {
+ tty->buf.head = head;
+ break;
+ }
+ head = tbuf->next;
+ if (head == NULL)
+ tty->buf.tail = NULL;
+ tty_buffer_free(tty, tbuf);
+ }
+ spin_unlock_irqrestore(&tty->buf.lock, flags);
+out:
+ tty_ldisc_deref(disc);
+}
+
+/*
+ * Routine which returns the baud rate of the tty
+ *
+ * Note that the baud_table needs to be kept in sync with the
+ * include/asm/termbits.h file.
+ */
+static int baud_table[] = {
+ 0, 50, 75, 110, 134, 150, 200, 300, 600, 1200, 1800, 2400, 4800,
+ 9600, 19200, 38400, 57600, 115200, 230400, 460800,
+#ifdef __sparc__
+ 76800, 153600, 307200, 614400, 921600
+#else
+ 500000, 576000, 921600, 1000000, 1152000, 1500000, 2000000,
+ 2500000, 3000000, 3500000, 4000000
+#endif
+};
+
+static int n_baud_table = ARRAY_SIZE(baud_table);
+
+/**
+ * tty_termios_baud_rate
+ * @termios: termios structure
+ *
+ * Convert termios baud rate data into a speed. This should be called
+ * with the termios lock held if this termios is a terminal termios
+ * structure. May change the termios data.
+ */
+
+int tty_termios_baud_rate(struct termios *termios)
+{
+ unsigned int cbaud;
+
+ cbaud = termios->c_cflag & CBAUD;
+
+ if (cbaud & CBAUDEX) {
+ cbaud &= ~CBAUDEX;
+
+ if (cbaud < 1 || cbaud + 15 > n_baud_table)
+ termios->c_cflag &= ~CBAUDEX;
+ else
+ cbaud += 15;
+ }
+ return baud_table[cbaud];
+}
+
+EXPORT_SYMBOL(tty_termios_baud_rate);
+
+/**
+ * tty_get_baud_rate - get tty bit rates
+ * @tty: tty to query
+ *
+ * Returns the baud rate as an integer for this terminal. The
+ * termios lock must be held by the caller and the terminal bit
+ * flags may be updated.
+ */
+
+int tty_get_baud_rate(struct tty_struct *tty)
+{
+ int baud = tty_termios_baud_rate(tty->termios);
+
+ if (baud == 38400 && tty->alt_speed) {
+ if (!tty->warned) {
+ printk(KERN_WARNING "Use of setserial/setrocket to "
+ "set SPD_* flags is deprecated\n");
+ tty->warned = 1;
+ }
+ baud = tty->alt_speed;
+ }
+
+ return baud;
+}
+
+EXPORT_SYMBOL(tty_get_baud_rate);
+
+/**
+ * tty_flip_buffer_push - terminal
+ * @tty: tty to push
+ *
+ * Queue a push of the terminal flip buffers to the line discipline. This
+ * function must not be called from IRQ context if tty->low_latency is set.
+ *
+ * In the event of the queue being busy for flipping the work will be
+ * held off and retried later.
+ */
+
+void tty_flip_buffer_push(struct tty_struct *tty)
+{
+ unsigned long flags;
+ spin_lock_irqsave(&tty->buf.lock, flags);
+ if (tty->buf.tail != NULL) {
+ tty->buf.tail->active = 0;
+ tty->buf.tail->commit = tty->buf.tail->used;
+ }
+ spin_unlock_irqrestore(&tty->buf.lock, flags);
+
+ if (tty->low_latency)
+ flush_to_ldisc((void *) tty);
+ else
+ schedule_delayed_work(&tty->buf.work, 1);
+}
+
+EXPORT_SYMBOL(tty_flip_buffer_push);
+
+
+/*
+ * This subroutine initializes a tty structure.
+ */
+static void initialize_tty_struct(struct tty_struct *tty)
+{
+ memset(tty, 0, sizeof(struct tty_struct));
+ tty->magic = TTY_MAGIC;
+ tty_ldisc_assign(tty, tty_ldisc_get(N_TTY));
+ tty->pgrp = -1;
+ tty->overrun_time = jiffies;
+ tty->buf.head = tty->buf.tail = NULL;
+ tty_buffer_init(tty);
+ INIT_WORK(&tty->buf.work, flush_to_ldisc, tty);
+ init_MUTEX(&tty->buf.pty_sem);
+ init_MUTEX(&tty->termios_sem);
+ init_waitqueue_head(&tty->write_wait);
+ init_waitqueue_head(&tty->read_wait);
+ INIT_WORK(&tty->hangup_work, do_tty_hangup, tty);
+ sema_init(&tty->atomic_read, 1);
+ sema_init(&tty->atomic_write, 1);
+ spin_lock_init(&tty->read_lock);
+ INIT_LIST_HEAD(&tty->tty_files);
+ INIT_WORK(&tty->SAK_work, NULL, NULL);
+}
+
+/*
+ * The default put_char routine if the driver did not define one.
+ */
+static void tty_default_put_char(struct tty_struct *tty, unsigned char ch)
+{
+ tty->driver->write(tty, &ch, 1);
+}
+
+static struct class *tty_class;
+
+/**
+ * tty_register_device - register a tty device
+ * @driver: the tty driver that describes the tty device
+ * @index: the index in the tty driver for this tty device
+ * @device: a struct device that is associated with this tty device.
+ * This field is optional, if there is no known struct device for this
+ * tty device it can be set to NULL safely.
+ *
+ * This call is required to be made to register an individual tty device if
+ * the tty driver's flags have the TTY_DRIVER_NO_DEVFS bit set. If that
+ * bit is not set, this function should not be called.
+ */
+void tty_register_device(struct tty_driver *driver, unsigned index,
+ struct device *device)
+{
+ char name[64];
+ dev_t dev = MKDEV(driver->major, driver->minor_start) + index;
+
+ if (index >= driver->num) {
+ printk(KERN_ERR "Attempt to register invalid tty line number "
+ " (%d).\n", index);
+ return;
+ }
+
+ devfs_mk_cdev(dev, S_IFCHR | S_IRUSR | S_IWUSR,
+ "%s%d", driver->devfs_name, index + driver->name_base);
+
+ if (driver->type == TTY_DRIVER_TYPE_PTY)
+ pty_line_name(driver, index, name);
+ else
+ tty_line_name(driver, index, name);
+ class_device_create(tty_class, NULL, dev, device, "%s", name);
+}
+
+/**
+ * tty_unregister_device - unregister a tty device
+ * @driver: the tty driver that describes the tty device
+ * @index: the index in the tty driver for this tty device
+ *
+ * If a tty device is registered with a call to tty_register_device() then
+ * this function must be made when the tty device is gone.
+ */
+void tty_unregister_device(struct tty_driver *driver, unsigned index)
+{
+ devfs_remove("%s%d", driver->devfs_name, index + driver->name_base);
+ class_device_destroy(tty_class, MKDEV(driver->major,
driver->minor_start) + index);
+}
+
+EXPORT_SYMBOL(tty_register_device);
+EXPORT_SYMBOL(tty_unregister_device);
+
+struct tty_driver *alloc_tty_driver(int lines)
+{
+ struct tty_driver *driver;
+
+ driver = kmalloc(sizeof(struct tty_driver), GFP_KERNEL);
+ if (driver) {
+ memset(driver, 0, sizeof(struct tty_driver));
+ driver->magic = TTY_DRIVER_MAGIC;
+ driver->num = lines;
+ /* later we'll move allocation of tables here */
+ }
+ return driver;
+}
+
+void put_tty_driver(struct tty_driver *driver)
+{
+ kfree(driver);
+}
+
+void tty_set_operations(struct tty_driver *driver, struct tty_operations *op)
+{
+ driver->open = op->open;
+ driver->close = op->close;
+ driver->write = op->write;
+ driver->put_char = op->put_char;
+ driver->flush_chars = op->flush_chars;
+ driver->write_room = op->write_room;
+ driver->chars_in_buffer = op->chars_in_buffer;
+ driver->ioctl = op->ioctl;
+ driver->set_termios = op->set_termios;
+ driver->throttle = op->throttle;
+ driver->unthrottle = op->unthrottle;
+ driver->stop = op->stop;
+ driver->start = op->start;
+ driver->hangup = op->hangup;
+ driver->break_ctl = op->break_ctl;
+ driver->flush_buffer = op->flush_buffer;
+ driver->set_ldisc = op->set_ldisc;
+ driver->wait_until_sent = op->wait_until_sent;
+ driver->send_xchar = op->send_xchar;
+ driver->read_proc = op->read_proc;
+ driver->write_proc = op->write_proc;
+ driver->tiocmget = op->tiocmget;
+ driver->tiocmset = op->tiocmset;
+}
+
+
+EXPORT_SYMBOL(alloc_tty_driver);
+EXPORT_SYMBOL(put_tty_driver);
+EXPORT_SYMBOL(tty_set_operations);
+
+/*
+ * Called by a tty driver to register itself.
+ */
+int tty_register_driver(struct tty_driver *driver)
+{
+ int error;
+ int i;
+ dev_t dev;
+ void **p = NULL;
+
+ if (driver->flags & TTY_DRIVER_INSTALLED)
+ return 0;
+
+ if (!(driver->flags & TTY_DRIVER_DEVPTS_MEM)) {
+ p = kmalloc(driver->num * 3 * sizeof(void *), GFP_KERNEL);
+ if (!p)
+ return -ENOMEM;
+ memset(p, 0, driver->num * 3 * sizeof(void *));
+ }
+
+ if (!driver->major) {
+ error = alloc_chrdev_region(&dev, driver->minor_start,
driver->num,
+ (char*)driver->name);
+ if (!error) {
+ driver->major = MAJOR(dev);
+ driver->minor_start = MINOR(dev);
+ }
+ } else {
+ dev = MKDEV(driver->major, driver->minor_start);
+ error = register_chrdev_region(dev, driver->num,
+ (char*)driver->name);
+ }
+ if (error < 0) {
+ kfree(p);
+ return error;
+ }
+
+ if (p) {
+ driver->ttys = (struct tty_struct **)p;
+ driver->termios = (struct termios **)(p + driver->num);
+ driver->termios_locked = (struct termios **)(p + driver->num *
2);
+ } else {
+ driver->ttys = NULL;
+ driver->termios = NULL;
+ driver->termios_locked = NULL;
+ }
+
+ cdev_init(&driver->cdev, &tty_fops);
+ driver->cdev.owner = driver->owner;
+ error = cdev_add(&driver->cdev, dev, driver->num);
+ if (error) {
+ cdev_del(&driver->cdev);
+ unregister_chrdev_region(dev, driver->num);
+ driver->ttys = NULL;
+ driver->termios = driver->termios_locked = NULL;
+ kfree(p);
+ return error;
+ }
+
+ if (!driver->put_char)
+ driver->put_char = tty_default_put_char;
+
+ list_add(&driver->tty_drivers, &tty_drivers);
+
+ if ( !(driver->flags & TTY_DRIVER_NO_DEVFS) ) {
+ for(i = 0; i < driver->num; i++)
+ tty_register_device(driver, i, NULL);
+ }
+ proc_tty_register_driver(driver);
+ return 0;
+}
+
+EXPORT_SYMBOL(tty_register_driver);
+
+/*
+ * Called by a tty driver to unregister itself.
+ */
+int tty_unregister_driver(struct tty_driver *driver)
+{
+ int i;
+ struct termios *tp;
+ void *p;
+
+ if (driver->refcount)
+ return -EBUSY;
+
+ unregister_chrdev_region(MKDEV(driver->major, driver->minor_start),
+ driver->num);
+
+ list_del(&driver->tty_drivers);
+
+ /*
+ * Free the termios and termios_locked structures because
+ * we don't want to get memory leaks when modular tty
+ * drivers are removed from the kernel.
+ */
+ for (i = 0; i < driver->num; i++) {
+ tp = driver->termios[i];
+ if (tp) {
+ driver->termios[i] = NULL;
+ kfree(tp);
+ }
+ tp = driver->termios_locked[i];
+ if (tp) {
+ driver->termios_locked[i] = NULL;
+ kfree(tp);
+ }
+ if (!(driver->flags & TTY_DRIVER_NO_DEVFS))
+ tty_unregister_device(driver, i);
+ }
+ p = driver->ttys;
+ proc_tty_unregister_driver(driver);
+ driver->ttys = NULL;
+ driver->termios = driver->termios_locked = NULL;
+ kfree(p);
+ cdev_del(&driver->cdev);
+ return 0;
+}
+
+EXPORT_SYMBOL(tty_unregister_driver);
+
+
+/*
+ * Initialize the console device. This is called *early*, so
+ * we can't necessarily depend on lots of kernel help here.
+ * Just do some early initializations, and do the complex setup
+ * later.
+ */
+void __init console_init(void)
+{
+ initcall_t *call;
+
+ /* Setup the default TTY line discipline. */
+ (void) tty_register_ldisc(N_TTY, &tty_ldisc_N_TTY);
+
+ /*
+ * set up the console device so that later boot sequences can
+ * inform about problems etc..
+ */
+#ifdef CONFIG_EARLY_PRINTK
+ disable_early_printk();
+#endif
+ call = __con_initcall_start;
+ while (call < __con_initcall_end) {
+ (*call)();
+ call++;
+ }
+}
+
+#ifdef CONFIG_VT
+extern int vty_init(void);
+#endif
+
+static int __init tty_class_init(void)
+{
+ tty_class = class_create(THIS_MODULE, "tty");
+ if (IS_ERR(tty_class))
+ return PTR_ERR(tty_class);
+ return 0;
+}
+
+postcore_initcall(tty_class_init);
+
+/* 3/2004 jmc: why do these devices exist? */
+
+static struct cdev tty_cdev, console_cdev;
+#ifdef CONFIG_UNIX98_PTYS
+static struct cdev ptmx_cdev;
+#endif
+#ifdef CONFIG_VT
+static struct cdev vc0_cdev;
+#endif
+
+/*
+ * Ok, now we can initialize the rest of the tty devices and can count
+ * on memory allocations, interrupts etc..
+ */
+static int __init tty_init(void)
+{
+ cdev_init(&tty_cdev, &tty_fops);
+ if (cdev_add(&tty_cdev, MKDEV(TTYAUX_MAJOR, 0), 1) ||
+ register_chrdev_region(MKDEV(TTYAUX_MAJOR, 0), 1, "/dev/tty") < 0)
+ panic("Couldn't register /dev/tty driver\n");
+ devfs_mk_cdev(MKDEV(TTYAUX_MAJOR, 0), S_IFCHR|S_IRUGO|S_IWUGO, "tty");
+ class_device_create(tty_class, NULL, MKDEV(TTYAUX_MAJOR, 0), NULL,
"tty");
+
+ cdev_init(&console_cdev, &console_fops);
+ if (cdev_add(&console_cdev, MKDEV(TTYAUX_MAJOR, 1), 1) ||
+ register_chrdev_region(MKDEV(TTYAUX_MAJOR, 1), 1, "/dev/console") <
0)
+ panic("Couldn't register /dev/console driver\n");
+ devfs_mk_cdev(MKDEV(TTYAUX_MAJOR, 1), S_IFCHR|S_IRUSR|S_IWUSR,
"console");
+ class_device_create(tty_class, NULL, MKDEV(TTYAUX_MAJOR, 1), NULL,
"console");
+
+#ifdef CONFIG_UNIX98_PTYS
+ cdev_init(&ptmx_cdev, &ptmx_fops);
+ if (cdev_add(&ptmx_cdev, MKDEV(TTYAUX_MAJOR, 2), 1) ||
+ register_chrdev_region(MKDEV(TTYAUX_MAJOR, 2), 1, "/dev/ptmx") < 0)
+ panic("Couldn't register /dev/ptmx driver\n");
+ devfs_mk_cdev(MKDEV(TTYAUX_MAJOR, 2), S_IFCHR|S_IRUGO|S_IWUGO, "ptmx");
+ class_device_create(tty_class, NULL, MKDEV(TTYAUX_MAJOR, 2), NULL,
"ptmx");
+#endif
+
+#ifdef CONFIG_VT
+ if (!console_use_vt)
+ goto out_vt;
+ cdev_init(&vc0_cdev, &console_fops);
+ if (cdev_add(&vc0_cdev, MKDEV(TTY_MAJOR, 0), 1) ||
+ register_chrdev_region(MKDEV(TTY_MAJOR, 0), 1, "/dev/vc/0") < 0)
+ panic("Couldn't register /dev/tty0 driver\n");
+ devfs_mk_cdev(MKDEV(TTY_MAJOR, 0), S_IFCHR|S_IRUSR|S_IWUSR, "vc/0");
+ class_device_create(tty_class, NULL, MKDEV(TTY_MAJOR, 0), NULL, "tty0");
+
+ vty_init();
+ out_vt:
+#endif
+ return 0;
+}
+module_init(tty_init);
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