![Colin Ian King](/assets/img/avatar_default.png)
An ENOMEM when creating a pair tty in tty_ldisc_setup causes a null pointer dereference in devpts_kill_index because tty->link->driver_data is NULL. The oops was triggered with the pty stressor in stress-ng when in a low memory condition. tty_init_dev tries to clean up a tty_ldisc_setup ENOMEM error by calling release_tty, however, this ultimately tries to clean up the NULL pair'd tty in pty_unix98_remove, triggering the Oops. Add check to pty_unix98_remove to only clean up fsi if it is not NULL. Ooops: [ 23.020961] Oops: 0000 [#1] SMP [ 23.020976] Modules linked in: ppdev snd_hda_codec_generic snd_hda_intel snd_hda_codec parport_pc snd_hda_core snd_hwdep parport snd_pcm input_leds joydev snd_timer serio_raw snd soundcore i2c_piix4 mac_hid ib_iser rdma_cm iw_cm ib_cm ib_core configfs iscsi_tcp libiscsi_tcp libiscsi scsi_transport_iscsi autofs4 btrfs raid10 raid456 async_raid6_recov async_memcpy async_pq async_xor async_tx xor raid6_pq libcrc32c raid1 raid0 multipath linear crct10dif_pclmul crc32_pclmul ghash_clmulni_intel aesni_intel qxl aes_x86_64 ttm lrw gf128mul glue_helper ablk_helper drm_kms_helper cryptd syscopyarea sysfillrect psmouse sysimgblt floppy fb_sys_fops drm pata_acpi jitterentropy_rng drbg ansi_cprng [ 23.020978] CPU: 0 PID: 1452 Comm: stress-ng-pty Not tainted 4.7.0-rc4+ #2 [ 23.020978] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS Ubuntu-1.8.2-1ubuntu1 04/01/2014 [ 23.020979] task: ffff88007ba30000 ti: ffff880078ea8000 task.ti: ffff880078ea8000 [ 23.020981] RIP: 0010:[<ffffffff813f11ff>] [<ffffffff813f11ff>] ida_remove+0x1f/0x120 [ 23.020981] RSP: 0018:ffff880078eabb60 EFLAGS: 00010a03 [ 23.020982] RAX: 4444444444444567 RBX: 0000000000000000 RCX: 000000000000001f [ 23.020982] RDX: 000000000000014c RSI: 000000000000026f RDI: 0000000000000000 [ 23.020982] RBP: ffff880078eabb70 R08: 0000000000000004 R09: 0000000000000036 [ 23.020983] R10: 000000000000026f R11: 0000000000000000 R12: 000000000000026f [ 23.020983] R13: 000000000000026f R14: ffff88007c944b40 R15: 000000000000026f [ 23.020984] FS: 00007f9a2f3cc700(0000) GS:ffff88007fc00000(0000) knlGS:0000000000000000 [ 23.020984] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 23.020985] CR2: 0000000000000010 CR3: 000000006c81b000 CR4: 00000000001406f0 [ 23.020988] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 [ 23.020988] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 [ 23.020988] Stack: [ 23.020989] 0000000000000000 000000000000026f ffff880078eabb90 ffffffff812a5a99 [ 23.020990] 0000000000000000 00000000fffffff4 ffff880078eabba8 ffffffff814f9cbe [ 23.020991] ffff88007965c800 ffff880078eabbc8 ffffffff814eef43 fffffffffffffff4 [ 23.020991] Call Trace: [ 23.021000] [<ffffffff812a5a99>] devpts_kill_index+0x29/0x50 [ 23.021002] [<ffffffff814f9cbe>] pty_unix98_remove+0x2e/0x50 [ 23.021006] [<ffffffff814eef43>] release_tty+0xb3/0x1b0 [ 23.021007] [<ffffffff814f18d4>] tty_init_dev+0xd4/0x1c0 [ 23.021011] [<ffffffff814f9fae>] ptmx_open+0xae/0x190 [ 23.021013] [<ffffffff812254ef>] chrdev_open+0xbf/0x1b0 [ 23.021015] [<ffffffff8121d973>] do_dentry_open+0x203/0x310 [ 23.021016] [<ffffffff81225430>] ? cdev_put+0x30/0x30 [ 23.021017] [<ffffffff8121ee44>] vfs_open+0x54/0x80 [ 23.021018] [<ffffffff8122b8fc>] ? may_open+0x8c/0x100 [ 23.021019] [<ffffffff8122f26b>] path_openat+0x2eb/0x1440 [ 23.021020] [<ffffffff81230534>] ? putname+0x54/0x60 [ 23.021022] [<ffffffff814f6f97>] ? n_tty_ioctl_helper+0x27/0x100 [ 23.021023] [<ffffffff81231651>] do_filp_open+0x91/0x100 [ 23.021024] [<ffffffff81230596>] ? getname_flags+0x56/0x1f0 [ 23.021026] [<ffffffff8123fc66>] ? __alloc_fd+0x46/0x190 [ 23.021027] [<ffffffff8121f1e4>] do_sys_open+0x124/0x210 [ 23.021028] [<ffffffff8121f2ee>] SyS_open+0x1e/0x20 [ 23.021035] [<ffffffff81845576>] entry_SYSCALL_64_fastpath+0x1e/0xa8 [ 23.021044] Code: 63 28 45 31 e4 eb dd 0f 1f 44 00 00 55 4c 63 d6 48 ba 89 88 88 88 88 88 88 88 4c 89 d0 b9 1f 00 00 00 48 f7 e2 48 89 e5 41 54 53 <8b> 47 10 48 89 fb 8d 3c c5 00 00 00 00 48 c1 ea 09 b8 01 00 00 [ 23.021045] RIP [<ffffffff813f11ff>] ida_remove+0x1f/0x120 [ 23.021045] RSP <ffff880078eabb60> [ 23.021046] CR2: 0000000000000010 Signed-off-by: Colin Ian King <colin.king@canonical.com> Cc: stable <stable@vger.kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
880 lines
22 KiB
C
880 lines
22 KiB
C
/*
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* Copyright (C) 1991, 1992 Linus Torvalds
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*
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* Added support for a Unix98-style ptmx device.
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* -- C. Scott Ananian <cananian@alumni.princeton.edu>, 14-Jan-1998
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*
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*/
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#include <linux/module.h>
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#include <linux/errno.h>
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#include <linux/interrupt.h>
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#include <linux/tty.h>
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#include <linux/tty_flip.h>
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#include <linux/fcntl.h>
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#include <linux/sched.h>
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#include <linux/string.h>
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#include <linux/major.h>
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#include <linux/mm.h>
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#include <linux/init.h>
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#include <linux/device.h>
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#include <linux/uaccess.h>
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#include <linux/bitops.h>
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#include <linux/devpts_fs.h>
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#include <linux/slab.h>
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#include <linux/mutex.h>
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#include <linux/poll.h>
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#undef TTY_DEBUG_HANGUP
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#ifdef TTY_DEBUG_HANGUP
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# define tty_debug_hangup(tty, f, args...) tty_debug(tty, f, ##args)
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#else
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# define tty_debug_hangup(tty, f, args...) do {} while (0)
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#endif
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#ifdef CONFIG_UNIX98_PTYS
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static struct tty_driver *ptm_driver;
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static struct tty_driver *pts_driver;
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static DEFINE_MUTEX(devpts_mutex);
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#endif
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static void pty_close(struct tty_struct *tty, struct file *filp)
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{
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BUG_ON(!tty);
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if (tty->driver->subtype == PTY_TYPE_MASTER)
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WARN_ON(tty->count > 1);
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else {
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if (tty_io_error(tty))
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return;
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if (tty->count > 2)
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return;
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}
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set_bit(TTY_IO_ERROR, &tty->flags);
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wake_up_interruptible(&tty->read_wait);
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wake_up_interruptible(&tty->write_wait);
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spin_lock_irq(&tty->ctrl_lock);
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tty->packet = 0;
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spin_unlock_irq(&tty->ctrl_lock);
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/* Review - krefs on tty_link ?? */
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if (!tty->link)
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return;
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set_bit(TTY_OTHER_CLOSED, &tty->link->flags);
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wake_up_interruptible(&tty->link->read_wait);
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wake_up_interruptible(&tty->link->write_wait);
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if (tty->driver->subtype == PTY_TYPE_MASTER) {
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set_bit(TTY_OTHER_CLOSED, &tty->flags);
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#ifdef CONFIG_UNIX98_PTYS
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if (tty->driver == ptm_driver) {
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mutex_lock(&devpts_mutex);
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if (tty->link->driver_data)
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devpts_pty_kill(tty->link->driver_data);
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mutex_unlock(&devpts_mutex);
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}
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#endif
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tty_vhangup(tty->link);
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}
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}
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/*
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* The unthrottle routine is called by the line discipline to signal
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* that it can receive more characters. For PTY's, the TTY_THROTTLED
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* flag is always set, to force the line discipline to always call the
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* unthrottle routine when there are fewer than TTY_THRESHOLD_UNTHROTTLE
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* characters in the queue. This is necessary since each time this
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* happens, we need to wake up any sleeping processes that could be
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* (1) trying to send data to the pty, or (2) waiting in wait_until_sent()
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* for the pty buffer to be drained.
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*/
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static void pty_unthrottle(struct tty_struct *tty)
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{
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tty_wakeup(tty->link);
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set_bit(TTY_THROTTLED, &tty->flags);
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}
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/**
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* pty_write - write to a pty
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* @tty: the tty we write from
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* @buf: kernel buffer of data
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* @count: bytes to write
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*
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* Our "hardware" write method. Data is coming from the ldisc which
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* may be in a non sleeping state. We simply throw this at the other
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* end of the link as if we were an IRQ handler receiving stuff for
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* the other side of the pty/tty pair.
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*/
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static int pty_write(struct tty_struct *tty, const unsigned char *buf, int c)
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{
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struct tty_struct *to = tty->link;
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if (tty->stopped)
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return 0;
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if (c > 0) {
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/* Stuff the data into the input queue of the other end */
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c = tty_insert_flip_string(to->port, buf, c);
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/* And shovel */
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if (c)
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tty_flip_buffer_push(to->port);
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}
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return c;
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}
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/**
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* pty_write_room - write space
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* @tty: tty we are writing from
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*
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* Report how many bytes the ldisc can send into the queue for
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* the other device.
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*/
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static int pty_write_room(struct tty_struct *tty)
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{
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if (tty->stopped)
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return 0;
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return tty_buffer_space_avail(tty->link->port);
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}
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/**
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* pty_chars_in_buffer - characters currently in our tx queue
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* @tty: our tty
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*
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* Report how much we have in the transmit queue. As everything is
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* instantly at the other end this is easy to implement.
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*/
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static int pty_chars_in_buffer(struct tty_struct *tty)
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{
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return 0;
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}
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/* Set the lock flag on a pty */
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static int pty_set_lock(struct tty_struct *tty, int __user *arg)
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{
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int val;
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if (get_user(val, arg))
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return -EFAULT;
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if (val)
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set_bit(TTY_PTY_LOCK, &tty->flags);
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else
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clear_bit(TTY_PTY_LOCK, &tty->flags);
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return 0;
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}
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static int pty_get_lock(struct tty_struct *tty, int __user *arg)
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{
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int locked = test_bit(TTY_PTY_LOCK, &tty->flags);
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return put_user(locked, arg);
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}
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/* Set the packet mode on a pty */
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static int pty_set_pktmode(struct tty_struct *tty, int __user *arg)
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{
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int pktmode;
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if (get_user(pktmode, arg))
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return -EFAULT;
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spin_lock_irq(&tty->ctrl_lock);
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if (pktmode) {
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if (!tty->packet) {
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tty->link->ctrl_status = 0;
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smp_mb();
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tty->packet = 1;
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}
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} else
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tty->packet = 0;
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spin_unlock_irq(&tty->ctrl_lock);
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return 0;
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}
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/* Get the packet mode of a pty */
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static int pty_get_pktmode(struct tty_struct *tty, int __user *arg)
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{
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int pktmode = tty->packet;
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return put_user(pktmode, arg);
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}
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/* Send a signal to the slave */
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static int pty_signal(struct tty_struct *tty, int sig)
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{
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struct pid *pgrp;
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if (sig != SIGINT && sig != SIGQUIT && sig != SIGTSTP)
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return -EINVAL;
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if (tty->link) {
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pgrp = tty_get_pgrp(tty->link);
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if (pgrp)
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kill_pgrp(pgrp, sig, 1);
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put_pid(pgrp);
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}
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return 0;
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}
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static void pty_flush_buffer(struct tty_struct *tty)
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{
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struct tty_struct *to = tty->link;
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struct tty_ldisc *ld;
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if (!to)
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return;
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ld = tty_ldisc_ref(to);
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tty_buffer_flush(to, ld);
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if (ld)
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tty_ldisc_deref(ld);
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if (to->packet) {
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spin_lock_irq(&tty->ctrl_lock);
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tty->ctrl_status |= TIOCPKT_FLUSHWRITE;
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wake_up_interruptible(&to->read_wait);
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spin_unlock_irq(&tty->ctrl_lock);
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}
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}
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static int pty_open(struct tty_struct *tty, struct file *filp)
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{
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if (!tty || !tty->link)
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return -ENODEV;
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if (test_bit(TTY_OTHER_CLOSED, &tty->flags))
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goto out;
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if (test_bit(TTY_PTY_LOCK, &tty->link->flags))
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goto out;
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if (tty->driver->subtype == PTY_TYPE_SLAVE && tty->link->count != 1)
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goto out;
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clear_bit(TTY_IO_ERROR, &tty->flags);
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clear_bit(TTY_OTHER_CLOSED, &tty->link->flags);
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set_bit(TTY_THROTTLED, &tty->flags);
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return 0;
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out:
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set_bit(TTY_IO_ERROR, &tty->flags);
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return -EIO;
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}
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static void pty_set_termios(struct tty_struct *tty,
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struct ktermios *old_termios)
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{
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/* See if packet mode change of state. */
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if (tty->link && tty->link->packet) {
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int extproc = (old_termios->c_lflag & EXTPROC) | L_EXTPROC(tty);
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int old_flow = ((old_termios->c_iflag & IXON) &&
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(old_termios->c_cc[VSTOP] == '\023') &&
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(old_termios->c_cc[VSTART] == '\021'));
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int new_flow = (I_IXON(tty) &&
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STOP_CHAR(tty) == '\023' &&
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START_CHAR(tty) == '\021');
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if ((old_flow != new_flow) || extproc) {
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spin_lock_irq(&tty->ctrl_lock);
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if (old_flow != new_flow) {
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tty->ctrl_status &= ~(TIOCPKT_DOSTOP | TIOCPKT_NOSTOP);
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if (new_flow)
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tty->ctrl_status |= TIOCPKT_DOSTOP;
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else
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tty->ctrl_status |= TIOCPKT_NOSTOP;
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}
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if (extproc)
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tty->ctrl_status |= TIOCPKT_IOCTL;
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spin_unlock_irq(&tty->ctrl_lock);
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wake_up_interruptible(&tty->link->read_wait);
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}
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}
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tty->termios.c_cflag &= ~(CSIZE | PARENB);
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tty->termios.c_cflag |= (CS8 | CREAD);
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}
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/**
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* pty_do_resize - resize event
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* @tty: tty being resized
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* @ws: window size being set.
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*
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* Update the termios variables and send the necessary signals to
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* peform a terminal resize correctly
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*/
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static int pty_resize(struct tty_struct *tty, struct winsize *ws)
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{
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struct pid *pgrp, *rpgrp;
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struct tty_struct *pty = tty->link;
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/* For a PTY we need to lock the tty side */
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mutex_lock(&tty->winsize_mutex);
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if (!memcmp(ws, &tty->winsize, sizeof(*ws)))
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goto done;
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/* Signal the foreground process group of both ptys */
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pgrp = tty_get_pgrp(tty);
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rpgrp = tty_get_pgrp(pty);
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if (pgrp)
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kill_pgrp(pgrp, SIGWINCH, 1);
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if (rpgrp != pgrp && rpgrp)
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kill_pgrp(rpgrp, SIGWINCH, 1);
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put_pid(pgrp);
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put_pid(rpgrp);
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tty->winsize = *ws;
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pty->winsize = *ws; /* Never used so will go away soon */
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done:
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mutex_unlock(&tty->winsize_mutex);
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return 0;
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}
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/**
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* pty_start - start() handler
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* pty_stop - stop() handler
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* @tty: tty being flow-controlled
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*
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* Propagates the TIOCPKT status to the master pty.
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*
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* NB: only the master pty can be in packet mode so only the slave
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* needs start()/stop() handlers
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*/
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static void pty_start(struct tty_struct *tty)
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{
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unsigned long flags;
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if (tty->link && tty->link->packet) {
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spin_lock_irqsave(&tty->ctrl_lock, flags);
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tty->ctrl_status &= ~TIOCPKT_STOP;
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tty->ctrl_status |= TIOCPKT_START;
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spin_unlock_irqrestore(&tty->ctrl_lock, flags);
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wake_up_interruptible_poll(&tty->link->read_wait, POLLIN);
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}
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}
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static void pty_stop(struct tty_struct *tty)
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{
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unsigned long flags;
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if (tty->link && tty->link->packet) {
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spin_lock_irqsave(&tty->ctrl_lock, flags);
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tty->ctrl_status &= ~TIOCPKT_START;
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tty->ctrl_status |= TIOCPKT_STOP;
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spin_unlock_irqrestore(&tty->ctrl_lock, flags);
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wake_up_interruptible_poll(&tty->link->read_wait, POLLIN);
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}
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}
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/**
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* pty_common_install - set up the pty pair
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* @driver: the pty driver
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* @tty: the tty being instantiated
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* @legacy: true if this is BSD style
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*
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* Perform the initial set up for the tty/pty pair. Called from the
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* tty layer when the port is first opened.
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*
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* Locking: the caller must hold the tty_mutex
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*/
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static int pty_common_install(struct tty_driver *driver, struct tty_struct *tty,
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bool legacy)
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{
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struct tty_struct *o_tty;
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struct tty_port *ports[2];
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int idx = tty->index;
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int retval = -ENOMEM;
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/* Opening the slave first has always returned -EIO */
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if (driver->subtype != PTY_TYPE_MASTER)
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return -EIO;
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ports[0] = kmalloc(sizeof **ports, GFP_KERNEL);
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ports[1] = kmalloc(sizeof **ports, GFP_KERNEL);
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if (!ports[0] || !ports[1])
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goto err;
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if (!try_module_get(driver->other->owner)) {
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/* This cannot in fact currently happen */
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goto err;
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}
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o_tty = alloc_tty_struct(driver->other, idx);
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if (!o_tty)
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goto err_put_module;
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tty_set_lock_subclass(o_tty);
|
|
lockdep_set_subclass(&o_tty->termios_rwsem, TTY_LOCK_SLAVE);
|
|
|
|
if (legacy) {
|
|
/* We always use new tty termios data so we can do this
|
|
the easy way .. */
|
|
tty_init_termios(tty);
|
|
tty_init_termios(o_tty);
|
|
|
|
driver->other->ttys[idx] = o_tty;
|
|
driver->ttys[idx] = tty;
|
|
} else {
|
|
memset(&tty->termios_locked, 0, sizeof(tty->termios_locked));
|
|
tty->termios = driver->init_termios;
|
|
memset(&o_tty->termios_locked, 0, sizeof(tty->termios_locked));
|
|
o_tty->termios = driver->other->init_termios;
|
|
}
|
|
|
|
/*
|
|
* Everything allocated ... set up the o_tty structure.
|
|
*/
|
|
tty_driver_kref_get(driver->other);
|
|
/* Establish the links in both directions */
|
|
tty->link = o_tty;
|
|
o_tty->link = tty;
|
|
tty_port_init(ports[0]);
|
|
tty_port_init(ports[1]);
|
|
tty_buffer_set_limit(ports[0], 8192);
|
|
tty_buffer_set_limit(ports[1], 8192);
|
|
o_tty->port = ports[0];
|
|
tty->port = ports[1];
|
|
o_tty->port->itty = o_tty;
|
|
|
|
tty_buffer_set_lock_subclass(o_tty->port);
|
|
|
|
tty_driver_kref_get(driver);
|
|
tty->count++;
|
|
o_tty->count++;
|
|
return 0;
|
|
|
|
err_put_module:
|
|
module_put(driver->other->owner);
|
|
err:
|
|
kfree(ports[0]);
|
|
kfree(ports[1]);
|
|
return retval;
|
|
}
|
|
|
|
static void pty_cleanup(struct tty_struct *tty)
|
|
{
|
|
tty_port_put(tty->port);
|
|
}
|
|
|
|
/* Traditional BSD devices */
|
|
#ifdef CONFIG_LEGACY_PTYS
|
|
|
|
static int pty_install(struct tty_driver *driver, struct tty_struct *tty)
|
|
{
|
|
return pty_common_install(driver, tty, true);
|
|
}
|
|
|
|
static void pty_remove(struct tty_driver *driver, struct tty_struct *tty)
|
|
{
|
|
struct tty_struct *pair = tty->link;
|
|
driver->ttys[tty->index] = NULL;
|
|
if (pair)
|
|
pair->driver->ttys[pair->index] = NULL;
|
|
}
|
|
|
|
static int pty_bsd_ioctl(struct tty_struct *tty,
|
|
unsigned int cmd, unsigned long arg)
|
|
{
|
|
switch (cmd) {
|
|
case TIOCSPTLCK: /* Set PT Lock (disallow slave open) */
|
|
return pty_set_lock(tty, (int __user *) arg);
|
|
case TIOCGPTLCK: /* Get PT Lock status */
|
|
return pty_get_lock(tty, (int __user *)arg);
|
|
case TIOCPKT: /* Set PT packet mode */
|
|
return pty_set_pktmode(tty, (int __user *)arg);
|
|
case TIOCGPKT: /* Get PT packet mode */
|
|
return pty_get_pktmode(tty, (int __user *)arg);
|
|
case TIOCSIG: /* Send signal to other side of pty */
|
|
return pty_signal(tty, (int) arg);
|
|
case TIOCGPTN: /* TTY returns ENOTTY, but glibc expects EINVAL here */
|
|
return -EINVAL;
|
|
}
|
|
return -ENOIOCTLCMD;
|
|
}
|
|
|
|
static int legacy_count = CONFIG_LEGACY_PTY_COUNT;
|
|
/*
|
|
* not really modular, but the easiest way to keep compat with existing
|
|
* bootargs behaviour is to continue using module_param here.
|
|
*/
|
|
module_param(legacy_count, int, 0);
|
|
|
|
/*
|
|
* The master side of a pty can do TIOCSPTLCK and thus
|
|
* has pty_bsd_ioctl.
|
|
*/
|
|
static const struct tty_operations master_pty_ops_bsd = {
|
|
.install = pty_install,
|
|
.open = pty_open,
|
|
.close = pty_close,
|
|
.write = pty_write,
|
|
.write_room = pty_write_room,
|
|
.flush_buffer = pty_flush_buffer,
|
|
.chars_in_buffer = pty_chars_in_buffer,
|
|
.unthrottle = pty_unthrottle,
|
|
.ioctl = pty_bsd_ioctl,
|
|
.cleanup = pty_cleanup,
|
|
.resize = pty_resize,
|
|
.remove = pty_remove
|
|
};
|
|
|
|
static const struct tty_operations slave_pty_ops_bsd = {
|
|
.install = pty_install,
|
|
.open = pty_open,
|
|
.close = pty_close,
|
|
.write = pty_write,
|
|
.write_room = pty_write_room,
|
|
.flush_buffer = pty_flush_buffer,
|
|
.chars_in_buffer = pty_chars_in_buffer,
|
|
.unthrottle = pty_unthrottle,
|
|
.set_termios = pty_set_termios,
|
|
.cleanup = pty_cleanup,
|
|
.resize = pty_resize,
|
|
.start = pty_start,
|
|
.stop = pty_stop,
|
|
.remove = pty_remove
|
|
};
|
|
|
|
static void __init legacy_pty_init(void)
|
|
{
|
|
struct tty_driver *pty_driver, *pty_slave_driver;
|
|
|
|
if (legacy_count <= 0)
|
|
return;
|
|
|
|
pty_driver = tty_alloc_driver(legacy_count,
|
|
TTY_DRIVER_RESET_TERMIOS |
|
|
TTY_DRIVER_REAL_RAW |
|
|
TTY_DRIVER_DYNAMIC_ALLOC);
|
|
if (IS_ERR(pty_driver))
|
|
panic("Couldn't allocate pty driver");
|
|
|
|
pty_slave_driver = tty_alloc_driver(legacy_count,
|
|
TTY_DRIVER_RESET_TERMIOS |
|
|
TTY_DRIVER_REAL_RAW |
|
|
TTY_DRIVER_DYNAMIC_ALLOC);
|
|
if (IS_ERR(pty_slave_driver))
|
|
panic("Couldn't allocate pty slave driver");
|
|
|
|
pty_driver->driver_name = "pty_master";
|
|
pty_driver->name = "pty";
|
|
pty_driver->major = PTY_MASTER_MAJOR;
|
|
pty_driver->minor_start = 0;
|
|
pty_driver->type = TTY_DRIVER_TYPE_PTY;
|
|
pty_driver->subtype = PTY_TYPE_MASTER;
|
|
pty_driver->init_termios = tty_std_termios;
|
|
pty_driver->init_termios.c_iflag = 0;
|
|
pty_driver->init_termios.c_oflag = 0;
|
|
pty_driver->init_termios.c_cflag = B38400 | CS8 | CREAD;
|
|
pty_driver->init_termios.c_lflag = 0;
|
|
pty_driver->init_termios.c_ispeed = 38400;
|
|
pty_driver->init_termios.c_ospeed = 38400;
|
|
pty_driver->other = pty_slave_driver;
|
|
tty_set_operations(pty_driver, &master_pty_ops_bsd);
|
|
|
|
pty_slave_driver->driver_name = "pty_slave";
|
|
pty_slave_driver->name = "ttyp";
|
|
pty_slave_driver->major = PTY_SLAVE_MAJOR;
|
|
pty_slave_driver->minor_start = 0;
|
|
pty_slave_driver->type = TTY_DRIVER_TYPE_PTY;
|
|
pty_slave_driver->subtype = PTY_TYPE_SLAVE;
|
|
pty_slave_driver->init_termios = tty_std_termios;
|
|
pty_slave_driver->init_termios.c_cflag = B38400 | CS8 | CREAD;
|
|
pty_slave_driver->init_termios.c_ispeed = 38400;
|
|
pty_slave_driver->init_termios.c_ospeed = 38400;
|
|
pty_slave_driver->other = pty_driver;
|
|
tty_set_operations(pty_slave_driver, &slave_pty_ops_bsd);
|
|
|
|
if (tty_register_driver(pty_driver))
|
|
panic("Couldn't register pty driver");
|
|
if (tty_register_driver(pty_slave_driver))
|
|
panic("Couldn't register pty slave driver");
|
|
}
|
|
#else
|
|
static inline void legacy_pty_init(void) { }
|
|
#endif
|
|
|
|
/* Unix98 devices */
|
|
#ifdef CONFIG_UNIX98_PTYS
|
|
|
|
static struct cdev ptmx_cdev;
|
|
|
|
static int pty_unix98_ioctl(struct tty_struct *tty,
|
|
unsigned int cmd, unsigned long arg)
|
|
{
|
|
switch (cmd) {
|
|
case TIOCSPTLCK: /* Set PT Lock (disallow slave open) */
|
|
return pty_set_lock(tty, (int __user *)arg);
|
|
case TIOCGPTLCK: /* Get PT Lock status */
|
|
return pty_get_lock(tty, (int __user *)arg);
|
|
case TIOCPKT: /* Set PT packet mode */
|
|
return pty_set_pktmode(tty, (int __user *)arg);
|
|
case TIOCGPKT: /* Get PT packet mode */
|
|
return pty_get_pktmode(tty, (int __user *)arg);
|
|
case TIOCGPTN: /* Get PT Number */
|
|
return put_user(tty->index, (unsigned int __user *)arg);
|
|
case TIOCSIG: /* Send signal to other side of pty */
|
|
return pty_signal(tty, (int) arg);
|
|
}
|
|
|
|
return -ENOIOCTLCMD;
|
|
}
|
|
|
|
/**
|
|
* ptm_unix98_lookup - find a pty master
|
|
* @driver: ptm driver
|
|
* @idx: tty index
|
|
*
|
|
* Look up a pty master device. Called under the tty_mutex for now.
|
|
* This provides our locking.
|
|
*/
|
|
|
|
static struct tty_struct *ptm_unix98_lookup(struct tty_driver *driver,
|
|
struct file *file, int idx)
|
|
{
|
|
/* Master must be open via /dev/ptmx */
|
|
return ERR_PTR(-EIO);
|
|
}
|
|
|
|
/**
|
|
* pts_unix98_lookup - find a pty slave
|
|
* @driver: pts driver
|
|
* @idx: tty index
|
|
*
|
|
* Look up a pty master device. Called under the tty_mutex for now.
|
|
* This provides our locking for the tty pointer.
|
|
*/
|
|
|
|
static struct tty_struct *pts_unix98_lookup(struct tty_driver *driver,
|
|
struct file *file, int idx)
|
|
{
|
|
struct tty_struct *tty;
|
|
|
|
mutex_lock(&devpts_mutex);
|
|
tty = devpts_get_priv(file->f_path.dentry);
|
|
mutex_unlock(&devpts_mutex);
|
|
/* Master must be open before slave */
|
|
if (!tty)
|
|
return ERR_PTR(-EIO);
|
|
return tty;
|
|
}
|
|
|
|
static int pty_unix98_install(struct tty_driver *driver, struct tty_struct *tty)
|
|
{
|
|
return pty_common_install(driver, tty, false);
|
|
}
|
|
|
|
/* this is called once with whichever end is closed last */
|
|
static void pty_unix98_remove(struct tty_driver *driver, struct tty_struct *tty)
|
|
{
|
|
struct pts_fs_info *fsi;
|
|
|
|
if (tty->driver->subtype == PTY_TYPE_MASTER)
|
|
fsi = tty->driver_data;
|
|
else
|
|
fsi = tty->link->driver_data;
|
|
|
|
if (fsi) {
|
|
devpts_kill_index(fsi, tty->index);
|
|
devpts_release(fsi);
|
|
}
|
|
}
|
|
|
|
static const struct tty_operations ptm_unix98_ops = {
|
|
.lookup = ptm_unix98_lookup,
|
|
.install = pty_unix98_install,
|
|
.remove = pty_unix98_remove,
|
|
.open = pty_open,
|
|
.close = pty_close,
|
|
.write = pty_write,
|
|
.write_room = pty_write_room,
|
|
.flush_buffer = pty_flush_buffer,
|
|
.chars_in_buffer = pty_chars_in_buffer,
|
|
.unthrottle = pty_unthrottle,
|
|
.ioctl = pty_unix98_ioctl,
|
|
.resize = pty_resize,
|
|
.cleanup = pty_cleanup
|
|
};
|
|
|
|
static const struct tty_operations pty_unix98_ops = {
|
|
.lookup = pts_unix98_lookup,
|
|
.install = pty_unix98_install,
|
|
.remove = pty_unix98_remove,
|
|
.open = pty_open,
|
|
.close = pty_close,
|
|
.write = pty_write,
|
|
.write_room = pty_write_room,
|
|
.flush_buffer = pty_flush_buffer,
|
|
.chars_in_buffer = pty_chars_in_buffer,
|
|
.unthrottle = pty_unthrottle,
|
|
.set_termios = pty_set_termios,
|
|
.start = pty_start,
|
|
.stop = pty_stop,
|
|
.cleanup = pty_cleanup,
|
|
};
|
|
|
|
/**
|
|
* ptmx_open - open a unix 98 pty master
|
|
* @inode: inode of device file
|
|
* @filp: file pointer to tty
|
|
*
|
|
* Allocate a unix98 pty master device from the ptmx driver.
|
|
*
|
|
* Locking: tty_mutex protects the init_dev work. tty->count should
|
|
* protect the rest.
|
|
* allocated_ptys_lock handles the list of free pty numbers
|
|
*/
|
|
|
|
static int ptmx_open(struct inode *inode, struct file *filp)
|
|
{
|
|
struct pts_fs_info *fsi;
|
|
struct tty_struct *tty;
|
|
struct dentry *dentry;
|
|
int retval;
|
|
int index;
|
|
|
|
nonseekable_open(inode, filp);
|
|
|
|
/* We refuse fsnotify events on ptmx, since it's a shared resource */
|
|
filp->f_mode |= FMODE_NONOTIFY;
|
|
|
|
retval = tty_alloc_file(filp);
|
|
if (retval)
|
|
return retval;
|
|
|
|
fsi = devpts_acquire(filp);
|
|
if (IS_ERR(fsi)) {
|
|
retval = PTR_ERR(fsi);
|
|
goto out_free_file;
|
|
}
|
|
|
|
/* find a device that is not in use. */
|
|
mutex_lock(&devpts_mutex);
|
|
index = devpts_new_index(fsi);
|
|
mutex_unlock(&devpts_mutex);
|
|
|
|
retval = index;
|
|
if (index < 0)
|
|
goto out_put_fsi;
|
|
|
|
|
|
mutex_lock(&tty_mutex);
|
|
tty = tty_init_dev(ptm_driver, index);
|
|
/* The tty returned here is locked so we can safely
|
|
drop the mutex */
|
|
mutex_unlock(&tty_mutex);
|
|
|
|
retval = PTR_ERR(tty);
|
|
if (IS_ERR(tty))
|
|
goto out;
|
|
|
|
/*
|
|
* From here on out, the tty is "live", and the index and
|
|
* fsi will be killed/put by the tty_release()
|
|
*/
|
|
set_bit(TTY_PTY_LOCK, &tty->flags); /* LOCK THE SLAVE */
|
|
tty->driver_data = fsi;
|
|
|
|
tty_add_file(tty, filp);
|
|
|
|
dentry = devpts_pty_new(fsi, index, tty->link);
|
|
if (IS_ERR(dentry)) {
|
|
retval = PTR_ERR(dentry);
|
|
goto err_release;
|
|
}
|
|
tty->link->driver_data = dentry;
|
|
|
|
retval = ptm_driver->ops->open(tty, filp);
|
|
if (retval)
|
|
goto err_release;
|
|
|
|
tty_debug_hangup(tty, "opening (count=%d)\n", tty->count);
|
|
|
|
tty_unlock(tty);
|
|
return 0;
|
|
err_release:
|
|
tty_unlock(tty);
|
|
// This will also put-ref the fsi
|
|
tty_release(inode, filp);
|
|
return retval;
|
|
out:
|
|
devpts_kill_index(fsi, index);
|
|
out_put_fsi:
|
|
devpts_release(fsi);
|
|
out_free_file:
|
|
tty_free_file(filp);
|
|
return retval;
|
|
}
|
|
|
|
static struct file_operations ptmx_fops;
|
|
|
|
static void __init unix98_pty_init(void)
|
|
{
|
|
ptm_driver = tty_alloc_driver(NR_UNIX98_PTY_MAX,
|
|
TTY_DRIVER_RESET_TERMIOS |
|
|
TTY_DRIVER_REAL_RAW |
|
|
TTY_DRIVER_DYNAMIC_DEV |
|
|
TTY_DRIVER_DEVPTS_MEM |
|
|
TTY_DRIVER_DYNAMIC_ALLOC);
|
|
if (IS_ERR(ptm_driver))
|
|
panic("Couldn't allocate Unix98 ptm driver");
|
|
pts_driver = tty_alloc_driver(NR_UNIX98_PTY_MAX,
|
|
TTY_DRIVER_RESET_TERMIOS |
|
|
TTY_DRIVER_REAL_RAW |
|
|
TTY_DRIVER_DYNAMIC_DEV |
|
|
TTY_DRIVER_DEVPTS_MEM |
|
|
TTY_DRIVER_DYNAMIC_ALLOC);
|
|
if (IS_ERR(pts_driver))
|
|
panic("Couldn't allocate Unix98 pts driver");
|
|
|
|
ptm_driver->driver_name = "pty_master";
|
|
ptm_driver->name = "ptm";
|
|
ptm_driver->major = UNIX98_PTY_MASTER_MAJOR;
|
|
ptm_driver->minor_start = 0;
|
|
ptm_driver->type = TTY_DRIVER_TYPE_PTY;
|
|
ptm_driver->subtype = PTY_TYPE_MASTER;
|
|
ptm_driver->init_termios = tty_std_termios;
|
|
ptm_driver->init_termios.c_iflag = 0;
|
|
ptm_driver->init_termios.c_oflag = 0;
|
|
ptm_driver->init_termios.c_cflag = B38400 | CS8 | CREAD;
|
|
ptm_driver->init_termios.c_lflag = 0;
|
|
ptm_driver->init_termios.c_ispeed = 38400;
|
|
ptm_driver->init_termios.c_ospeed = 38400;
|
|
ptm_driver->other = pts_driver;
|
|
tty_set_operations(ptm_driver, &ptm_unix98_ops);
|
|
|
|
pts_driver->driver_name = "pty_slave";
|
|
pts_driver->name = "pts";
|
|
pts_driver->major = UNIX98_PTY_SLAVE_MAJOR;
|
|
pts_driver->minor_start = 0;
|
|
pts_driver->type = TTY_DRIVER_TYPE_PTY;
|
|
pts_driver->subtype = PTY_TYPE_SLAVE;
|
|
pts_driver->init_termios = tty_std_termios;
|
|
pts_driver->init_termios.c_cflag = B38400 | CS8 | CREAD;
|
|
pts_driver->init_termios.c_ispeed = 38400;
|
|
pts_driver->init_termios.c_ospeed = 38400;
|
|
pts_driver->other = ptm_driver;
|
|
tty_set_operations(pts_driver, &pty_unix98_ops);
|
|
|
|
if (tty_register_driver(ptm_driver))
|
|
panic("Couldn't register Unix98 ptm driver");
|
|
if (tty_register_driver(pts_driver))
|
|
panic("Couldn't register Unix98 pts driver");
|
|
|
|
/* Now create the /dev/ptmx special device */
|
|
tty_default_fops(&ptmx_fops);
|
|
ptmx_fops.open = ptmx_open;
|
|
|
|
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");
|
|
device_create(tty_class, NULL, MKDEV(TTYAUX_MAJOR, 2), NULL, "ptmx");
|
|
}
|
|
|
|
#else
|
|
static inline void unix98_pty_init(void) { }
|
|
#endif
|
|
|
|
static int __init pty_init(void)
|
|
{
|
|
legacy_pty_init();
|
|
unix98_pty_init();
|
|
return 0;
|
|
}
|
|
device_initcall(pty_init);
|