diff options
Diffstat (limited to 'drivers/tty/tty_io.c')
| -rw-r--r-- | drivers/tty/tty_io.c | 456 |
1 files changed, 224 insertions, 232 deletions
diff --git a/drivers/tty/tty_io.c b/drivers/tty/tty_io.c index 3149114bf130..e2d92cf70eb7 100644 --- a/drivers/tty/tty_io.c +++ b/drivers/tty/tty_io.c @@ -101,6 +101,7 @@ #include <linux/compat.h> #include <linux/uaccess.h> #include <linux/termios_internal.h> +#include <linux/fs.h> #include <linux/kbd_kern.h> #include <linux/vt_kern.h> @@ -158,7 +159,7 @@ static int tty_fasync(int fd, struct file *filp, int on); static void release_tty(struct tty_struct *tty, int idx); /** - * free_tty_struct - free a disused tty + * free_tty_struct - free a disused tty * @tty: tty struct to free * * Free the write buffers, tty queue and tty memory itself. @@ -232,7 +233,7 @@ static void tty_del_file(struct file *file) } /** - * tty_name - return tty naming + * tty_name - return tty naming * @tty: tty structure * * Convert a tty structure into a name. The name reflects the kernel naming @@ -269,17 +270,16 @@ static int tty_paranoia_check(struct tty_struct *tty, struct inode *inode, } /* Caller must hold tty_lock */ -static int check_tty_count(struct tty_struct *tty, const char *routine) +static void check_tty_count(struct tty_struct *tty, const char *routine) { #ifdef CHECK_TTY_COUNT struct list_head *p; int count = 0, kopen_count = 0; - spin_lock(&tty->files_lock); - list_for_each(p, &tty->tty_files) { - count++; - } - spin_unlock(&tty->files_lock); + scoped_guard(spinlock, &tty->files_lock) + list_for_each(p, &tty->tty_files) + count++; + if (tty->driver->type == TTY_DRIVER_TYPE_PTY && tty->driver->subtype == PTY_TYPE_SLAVE && tty->link && tty->link->count) @@ -289,14 +289,12 @@ static int check_tty_count(struct tty_struct *tty, const char *routine) if (tty->count != (count + kopen_count)) { tty_warn(tty, "%s: tty->count(%d) != (#fd's(%d) + #kopen's(%d))\n", routine, tty->count, count, kopen_count); - return (count + kopen_count); } #endif - return 0; } /** - * get_tty_driver - find device of a tty + * get_tty_driver - find device of a tty * @device: device identifier * @index: returns the index of the tty * @@ -321,7 +319,7 @@ static struct tty_driver *get_tty_driver(dev_t device, int *index) } /** - * tty_dev_name_to_number - return dev_t for device name + * tty_dev_name_to_number - return dev_t for device name * @name: user space name of device under /dev * @number: pointer to dev_t that this function will populate * @@ -351,29 +349,26 @@ int tty_dev_name_to_number(const char *name, dev_t *number) return ret; prefix_length = str - name; - mutex_lock(&tty_mutex); + + guard(mutex)(&tty_mutex); list_for_each_entry(p, &tty_drivers, tty_drivers) if (prefix_length == strlen(p->name) && strncmp(name, p->name, prefix_length) == 0) { if (index < p->num) { *number = MKDEV(p->major, p->minor_start + index); - goto out; + return 0; } } - /* if here then driver wasn't found */ - ret = -ENODEV; -out: - mutex_unlock(&tty_mutex); - return ret; + return -ENODEV; } EXPORT_SYMBOL_GPL(tty_dev_name_to_number); #ifdef CONFIG_CONSOLE_POLL /** - * tty_find_polling_driver - find device of a polled tty + * tty_find_polling_driver - find device of a polled tty * @name: name string to match * @line: pointer to resulting tty line nr * @@ -382,7 +377,7 @@ EXPORT_SYMBOL_GPL(tty_dev_name_to_number); */ struct tty_driver *tty_find_polling_driver(char *name, int *line) { - struct tty_driver *p, *res = NULL; + struct tty_driver *p; int tty_line = 0; int len; char *str, *stp; @@ -396,7 +391,8 @@ struct tty_driver *tty_find_polling_driver(char *name, int *line) len = str - name; tty_line = simple_strtoul(str, &str, 10); - mutex_lock(&tty_mutex); + guard(mutex)(&tty_mutex); + /* Search through the tty devices to look for a match */ list_for_each_entry(p, &tty_drivers, tty_drivers) { if (!len || strncmp(name, p->name, len) != 0) @@ -409,14 +405,12 @@ struct tty_driver *tty_find_polling_driver(char *name, int *line) if (tty_line >= 0 && tty_line < p->num && p->ops && p->ops->poll_init && !p->ops->poll_init(p, tty_line, stp)) { - res = tty_driver_kref_get(p); *line = tty_line; - break; + return tty_driver_kref_get(p); } } - mutex_unlock(&tty_mutex); - return res; + return NULL; } EXPORT_SYMBOL_GPL(tty_find_polling_driver); #endif @@ -463,10 +457,9 @@ static void tty_show_fdinfo(struct seq_file *m, struct file *file) } static const struct file_operations tty_fops = { - .llseek = no_llseek, .read_iter = tty_read, .write_iter = tty_write, - .splice_read = generic_file_splice_read, + .splice_read = copy_splice_read, .splice_write = iter_file_splice_write, .poll = tty_poll, .unlocked_ioctl = tty_ioctl, @@ -478,10 +471,9 @@ static const struct file_operations tty_fops = { }; static const struct file_operations console_fops = { - .llseek = no_llseek, .read_iter = tty_read, .write_iter = redirected_tty_write, - .splice_read = generic_file_splice_read, + .splice_read = copy_splice_read, .splice_write = iter_file_splice_write, .poll = tty_poll, .unlocked_ioctl = tty_ioctl, @@ -492,7 +484,6 @@ static const struct file_operations console_fops = { }; static const struct file_operations hung_up_tty_fops = { - .llseek = no_llseek, .read_iter = hung_up_tty_read, .write_iter = hung_up_tty_write, .poll = hung_up_tty_poll, @@ -506,7 +497,7 @@ static DEFINE_SPINLOCK(redirect_lock); static struct file *redirect; /** - * tty_wakeup - request more data + * tty_wakeup - request more data * @tty: terminal * * Internal and external helper for wakeups of tty. This function informs the @@ -530,7 +521,7 @@ void tty_wakeup(struct tty_struct *tty) EXPORT_SYMBOL_GPL(tty_wakeup); /** - * tty_release_redirect - Release a redirect on a pty if present + * tty_release_redirect - Release a redirect on a pty if present * @tty: tty device * * This is available to the pty code so if the master closes, if the slave is a @@ -538,20 +529,19 @@ EXPORT_SYMBOL_GPL(tty_wakeup); */ static struct file *tty_release_redirect(struct tty_struct *tty) { - struct file *f = NULL; + guard(spinlock)(&redirect_lock); - spin_lock(&redirect_lock); if (redirect && file_tty(redirect) == tty) { - f = redirect; + struct file *f = redirect; redirect = NULL; + return f; } - spin_unlock(&redirect_lock); - return f; + return NULL; } /** - * __tty_hangup - actual handler for hangup events + * __tty_hangup - actual handler for hangup events * @tty: tty device * @exit_session: if non-zero, signal all foreground group processes * @@ -674,7 +664,7 @@ static void do_tty_hangup(struct work_struct *work) } /** - * tty_hangup - trigger a hangup event + * tty_hangup - trigger a hangup event * @tty: tty to hangup * * A carrier loss (virtual or otherwise) has occurred on @tty. Schedule a @@ -688,7 +678,7 @@ void tty_hangup(struct tty_struct *tty) EXPORT_SYMBOL(tty_hangup); /** - * tty_vhangup - process vhangup + * tty_vhangup - process vhangup * @tty: tty to hangup * * The user has asked via system call for the terminal to be hung up. We do @@ -704,7 +694,7 @@ EXPORT_SYMBOL(tty_vhangup); /** - * tty_vhangup_self - process vhangup for own ctty + * tty_vhangup_self - process vhangup for own ctty * * Perform a vhangup on the current controlling tty */ @@ -720,7 +710,7 @@ void tty_vhangup_self(void) } /** - * tty_vhangup_session - hangup session leader exit + * tty_vhangup_session - hangup session leader exit * @tty: tty to hangup * * The session leader is exiting and hanging up its controlling terminal. @@ -736,7 +726,7 @@ void tty_vhangup_session(struct tty_struct *tty) } /** - * tty_hung_up_p - was tty hung up + * tty_hung_up_p - was tty hung up * @filp: file pointer of tty * * Return: true if the tty has been subject to a vhangup or a carrier loss @@ -757,7 +747,7 @@ void __stop_tty(struct tty_struct *tty) } /** - * stop_tty - propagate flow control + * stop_tty - propagate flow control * @tty: tty to stop * * Perform flow control to the driver. May be called on an already stopped @@ -772,11 +762,8 @@ void __stop_tty(struct tty_struct *tty) */ void stop_tty(struct tty_struct *tty) { - unsigned long flags; - - spin_lock_irqsave(&tty->flow.lock, flags); + guard(spinlock_irqsave)(&tty->flow.lock); __stop_tty(tty); - spin_unlock_irqrestore(&tty->flow.lock, flags); } EXPORT_SYMBOL(stop_tty); @@ -791,7 +778,7 @@ void __start_tty(struct tty_struct *tty) } /** - * start_tty - propagate flow control + * start_tty - propagate flow control * @tty: tty to start * * Start a tty that has been stopped if at all possible. If @tty was previously @@ -803,26 +790,35 @@ void __start_tty(struct tty_struct *tty) */ void start_tty(struct tty_struct *tty) { - unsigned long flags; - - spin_lock_irqsave(&tty->flow.lock, flags); + guard(spinlock_irqsave)(&tty->flow.lock); __start_tty(tty); - spin_unlock_irqrestore(&tty->flow.lock, flags); } EXPORT_SYMBOL(start_tty); -static void tty_update_time(struct timespec64 *time) +static void tty_update_time(struct tty_struct *tty, bool mtime) { time64_t sec = ktime_get_real_seconds(); + struct tty_file_private *priv; - /* - * We only care if the two values differ in anything other than the - * lower three bits (i.e every 8 seconds). If so, then we can update - * the time of the tty device, otherwise it could be construded as a - * security leak to let userspace know the exact timing of the tty. - */ - if ((sec ^ time->tv_sec) & ~7) - time->tv_sec = sec; + guard(spinlock)(&tty->files_lock); + + list_for_each_entry(priv, &tty->tty_files, list) { + struct inode *inode = file_inode(priv->file); + struct timespec64 time = mtime ? inode_get_mtime(inode) : inode_get_atime(inode); + + /* + * We only care if the two values differ in anything other than the + * lower three bits (i.e every 8 seconds). If so, then we can update + * the time of the tty device, otherwise it could be construded as a + * security leak to let userspace know the exact timing of the tty. + */ + if ((sec ^ time.tv_sec) & ~7) { + if (mtime) + inode_set_mtime(inode, sec, 0); + else + inode_set_atime(inode, sec, 0); + } + } } /* @@ -836,19 +832,18 @@ static void tty_update_time(struct timespec64 *time) * data or clears the cookie. The cookie may be something that the * ldisc maintains state for and needs to free. */ -static int iterate_tty_read(struct tty_ldisc *ld, struct tty_struct *tty, - struct file *file, struct iov_iter *to) +static ssize_t iterate_tty_read(struct tty_ldisc *ld, struct tty_struct *tty, + struct file *file, struct iov_iter *to) { - int retval = 0; void *cookie = NULL; unsigned long offset = 0; - char kernel_buf[64]; - size_t count = iov_iter_count(to); + ssize_t retval = 0; + size_t copied, count = iov_iter_count(to); + u8 kernel_buf[64]; do { - int size, copied; + ssize_t size = min(count, sizeof(kernel_buf)); - size = count > sizeof(kernel_buf) ? sizeof(kernel_buf) : count; size = ld->ops->read(tty, file, kernel_buf, size, &cookie, offset); if (!size) break; @@ -892,7 +887,7 @@ static int iterate_tty_read(struct tty_ldisc *ld, struct tty_struct *tty, /** - * tty_read - read method for tty device files + * tty_read - read method for tty device files * @iocb: kernel I/O control block * @to: destination for the data read * @@ -905,11 +900,11 @@ static int iterate_tty_read(struct tty_ldisc *ld, struct tty_struct *tty, */ static ssize_t tty_read(struct kiocb *iocb, struct iov_iter *to) { - int i; struct file *file = iocb->ki_filp; struct inode *inode = file_inode(file); struct tty_struct *tty = file_tty(file); struct tty_ldisc *ld; + ssize_t ret; if (tty_paranoia_check(tty, inode, "tty_read")) return -EIO; @@ -922,24 +917,24 @@ static ssize_t tty_read(struct kiocb *iocb, struct iov_iter *to) ld = tty_ldisc_ref_wait(tty); if (!ld) return hung_up_tty_read(iocb, to); - i = -EIO; + ret = -EIO; if (ld->ops->read) - i = iterate_tty_read(ld, tty, file, to); + ret = iterate_tty_read(ld, tty, file, to); tty_ldisc_deref(ld); - if (i > 0) - tty_update_time(&inode->i_atime); + if (ret > 0) + tty_update_time(tty, false); - return i; + return ret; } -static void tty_write_unlock(struct tty_struct *tty) +void tty_write_unlock(struct tty_struct *tty) { mutex_unlock(&tty->atomic_write_lock); wake_up_interruptible_poll(&tty->write_wait, EPOLLOUT); } -static int tty_write_lock(struct tty_struct *tty, int ndelay) +int tty_write_lock(struct tty_struct *tty, bool ndelay) { if (!mutex_trylock(&tty->atomic_write_lock)) { if (ndelay) @@ -954,15 +949,11 @@ static int tty_write_lock(struct tty_struct *tty, int ndelay) * 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, - struct iov_iter *from) +static ssize_t iterate_tty_write(struct tty_ldisc *ld, struct tty_struct *tty, + struct file *file, struct iov_iter *from) { - size_t count = iov_iter_count(from); + size_t chunk, count = iov_iter_count(from); ssize_t ret, written = 0; - unsigned int chunk; ret = tty_write_lock(tty, file->f_flags & O_NDELAY); if (ret < 0) @@ -989,7 +980,7 @@ static inline ssize_t do_tty_write( /* write_buf/write_cnt is protected by the atomic_write_lock mutex */ if (tty->write_cnt < chunk) { - unsigned char *buf_chunk; + u8 *buf_chunk; if (chunk < 1024) chunk = 1024; @@ -1006,16 +997,13 @@ static inline ssize_t do_tty_write( /* Do the write .. */ for (;;) { - size_t size = count; - - if (size > chunk) - size = chunk; + size_t size = min(chunk, count); ret = -EFAULT; if (copy_from_iter(tty->write_buf, size, from) != size) break; - ret = write(tty, file, tty->write_buf, size); + ret = ld->ops->write(tty, file, tty->write_buf, size); if (ret <= 0) break; @@ -1036,7 +1024,7 @@ static inline ssize_t do_tty_write( cond_resched(); } if (written) { - tty_update_time(&file_inode(file)->i_mtime); + tty_update_time(tty, true); ret = written; } out: @@ -1044,6 +1032,7 @@ out: return ret; } +#ifdef CONFIG_PRINT_QUOTA_WARNING /** * tty_write_message - write a message to a certain tty, not just the console. * @tty: the destination tty_struct @@ -1054,6 +1043,8 @@ out: * needed. * * We must still hold the BTM and test the CLOSING flag for the moment. + * + * This function is DEPRECATED, do not use in new code. */ void tty_write_message(struct tty_struct *tty, char *msg) { @@ -1066,6 +1057,7 @@ void tty_write_message(struct tty_struct *tty, char *msg) tty_write_unlock(tty); } } +#endif static ssize_t file_tty_write(struct file *file, struct kiocb *iocb, struct iov_iter *from) { @@ -1086,13 +1078,13 @@ static ssize_t file_tty_write(struct file *file, struct kiocb *iocb, struct iov_ if (!ld->ops->write) ret = -EIO; else - ret = do_tty_write(ld->ops->write, tty, file, from); + ret = iterate_tty_write(ld, tty, file, from); tty_ldisc_deref(ld); return ret; } /** - * tty_write - write method for tty device file + * tty_write - write method for tty device file * @iocb: kernel I/O control block * @from: iov_iter with data to write * @@ -1134,7 +1126,7 @@ ssize_t redirected_tty_write(struct kiocb *iocb, struct iov_iter *iter) } /** - * tty_send_xchar - send priority character + * tty_send_xchar - send priority character * @tty: the tty to send to * @ch: xchar to send * @@ -1142,7 +1134,7 @@ ssize_t redirected_tty_write(struct kiocb *iocb, struct iov_iter *iter) * * Locking: none for xchar method, write ordering for write method. */ -int tty_send_xchar(struct tty_struct *tty, char ch) +int tty_send_xchar(struct tty_struct *tty, u8 ch) { bool was_stopped = tty->flow.stopped; @@ -1153,7 +1145,7 @@ int tty_send_xchar(struct tty_struct *tty, char ch) return 0; } - if (tty_write_lock(tty, 0) < 0) + if (tty_write_lock(tty, false) < 0) return -ERESTARTSYS; down_read(&tty->termios_rwsem); @@ -1168,7 +1160,7 @@ int tty_send_xchar(struct tty_struct *tty, char ch) } /** - * pty_line_name - generate name for a pty + * pty_line_name - generate name for a pty * @driver: the tty driver in use * @index: the minor number * @p: output buffer of at least 6 bytes @@ -1189,7 +1181,7 @@ static void pty_line_name(struct tty_driver *driver, int index, char *p) } /** - * tty_line_name - generate name for a tty + * tty_line_name - generate name for a tty * @driver: the tty driver in use * @index: the minor number * @p: output buffer of at least 7 bytes @@ -1224,21 +1216,23 @@ static struct tty_struct *tty_driver_lookup_tty(struct tty_driver *driver, { struct tty_struct *tty; - if (driver->ops->lookup) + if (driver->ops->lookup) { if (!file) tty = ERR_PTR(-EIO); else tty = driver->ops->lookup(driver, file, idx); - else + } else { + if (idx >= driver->num) + return ERR_PTR(-EINVAL); tty = driver->ttys[idx]; - + } if (!IS_ERR(tty)) tty_kref_get(tty); return tty; } /** - * tty_init_termios - helper for termios setup + * tty_init_termios - helper for termios setup * @tty: the tty to set up * * Initialise the termios structure for this tty. This runs under the @@ -1321,7 +1315,7 @@ static void tty_driver_remove_tty(struct tty_driver *driver, struct tty_struct * } /** - * tty_reopen() - fast re-open of an open tty + * tty_reopen() - fast re-open of an open tty * @tty: the tty to open * * Re-opens on master ptys are not allowed and return -%EIO. @@ -1365,7 +1359,7 @@ static int tty_reopen(struct tty_struct *tty) } /** - * tty_init_dev - initialise a tty device + * tty_init_dev - initialise a tty device * @driver: tty driver we are opening a device on * @idx: device index * @@ -1487,7 +1481,7 @@ void tty_save_termios(struct tty_struct *tty) EXPORT_SYMBOL_GPL(tty_save_termios); /** - * tty_flush_works - flush all works of a tty/pty pair + * tty_flush_works - flush all works of a tty/pty pair * @tty: tty device to flush works for (or either end of a pty pair) * * Sync flush all works belonging to @tty (and the 'other' tty). @@ -1503,7 +1497,7 @@ static void tty_flush_works(struct tty_struct *tty) } /** - * release_one_tty - release tty structure memory + * release_one_tty - release tty structure memory * @work: work of tty we are obliterating * * Releases memory associated with a tty structure, and clears out the @@ -1551,7 +1545,7 @@ static void queue_release_one_tty(struct kref *kref) } /** - * tty_kref_put - release a tty kref + * tty_kref_put - release a tty kref * @tty: tty device * * Release a reference to the @tty device and if need be let the kref layer @@ -1565,7 +1559,7 @@ void tty_kref_put(struct tty_struct *tty) EXPORT_SYMBOL(tty_kref_put); /** - * release_tty - release tty structure memory + * release_tty - release tty structure memory * @tty: tty device release * @idx: index of the tty device release * @@ -1642,7 +1636,7 @@ static int tty_release_checks(struct tty_struct *tty, int idx) } /** - * tty_kclose - closes tty opened by tty_kopen + * tty_kclose - closes tty opened by tty_kopen * @tty: tty device * * Performs the final steps to release and free a tty device. It is the same as @@ -1672,7 +1666,7 @@ void tty_kclose(struct tty_struct *tty) EXPORT_SYMBOL_GPL(tty_kclose); /** - * tty_release_struct - release a tty struct + * tty_release_struct - release a tty struct * @tty: tty device * @idx: index of the tty * @@ -1701,7 +1695,7 @@ void tty_release_struct(struct tty_struct *tty, int idx) EXPORT_SYMBOL_GPL(tty_release_struct); /** - * tty_release - vfs callback for close + * tty_release - vfs callback for close * @inode: inode of tty * @filp: file pointer for handle to tty * @@ -1982,7 +1976,7 @@ out: } /** - * tty_kopen_exclusive - open a tty device for kernel + * tty_kopen_exclusive - open a tty device for kernel * @device: dev_t of device to open * * Opens tty exclusively for kernel. Performs the driver lookup, makes sure @@ -2002,7 +1996,7 @@ struct tty_struct *tty_kopen_exclusive(dev_t device) EXPORT_SYMBOL_GPL(tty_kopen_exclusive); /** - * tty_kopen_shared - open a tty device for shared in-kernel use + * tty_kopen_shared - open a tty device for shared in-kernel use * @device: dev_t of device to open * * Opens an already existing tty for in-kernel use. Compared to @@ -2017,7 +2011,7 @@ struct tty_struct *tty_kopen_shared(dev_t device) EXPORT_SYMBOL_GPL(tty_kopen_shared); /** - * tty_open_by_driver - open a tty device + * tty_open_by_driver - open a tty device * @device: dev_t of device to open * @filp: file pointer to tty * @@ -2085,7 +2079,7 @@ out: } /** - * tty_open - open a tty device + * tty_open - open a tty device * @inode: inode of device file * @filp: file pointer to tty * @@ -2179,7 +2173,7 @@ retry_open: /** - * tty_poll - check tty status + * tty_poll - check tty status * @filp: file being polled * @wait: poll wait structures to update * @@ -2216,6 +2210,12 @@ static int __tty_fasync(int fd, struct file *filp, int on) if (tty_paranoia_check(tty, file_inode(filp), "tty_fasync")) goto out; + if (on) { + retval = file_f_owner_allocate(filp); + if (retval) + goto out; + } + retval = fasync_helper(fd, filp, on, &tty->fasync); if (retval <= 0) goto out; @@ -2257,7 +2257,7 @@ static int tty_fasync(int fd, struct file *filp, int on) static bool tty_legacy_tiocsti __read_mostly = IS_ENABLED(CONFIG_LEGACY_TIOCSTI); /** - * tiocsti - fake input character + * tiocsti - fake input character * @tty: tty to fake input into * @p: pointer to character * @@ -2269,12 +2269,12 @@ static bool tty_legacy_tiocsti __read_mostly = IS_ENABLED(CONFIG_LEGACY_TIOCSTI) * * Called functions take tty_ldiscs_lock * * current->signal->tty check is safe without locks */ -static int tiocsti(struct tty_struct *tty, char __user *p) +static int tiocsti(struct tty_struct *tty, u8 __user *p) { - char ch, mbz = 0; struct tty_ldisc *ld; + u8 ch; - if (!tty_legacy_tiocsti) + if (!tty_legacy_tiocsti && !capable(CAP_SYS_ADMIN)) return -EIO; if ((current->signal->tty != tty) && !capable(CAP_SYS_ADMIN)) @@ -2287,14 +2287,14 @@ static int tiocsti(struct tty_struct *tty, char __user *p) return -EIO; tty_buffer_lock_exclusive(tty->port); if (ld->ops->receive_buf) - ld->ops->receive_buf(tty, &ch, &mbz, 1); + ld->ops->receive_buf(tty, &ch, NULL, 1); tty_buffer_unlock_exclusive(tty->port); tty_ldisc_deref(ld); return 0; } /** - * tiocgwinsz - implement window query ioctl + * tiocgwinsz - implement window query ioctl * @tty: tty * @arg: user buffer for result * @@ -2305,17 +2305,16 @@ static int tiocsti(struct tty_struct *tty, char __user *p) */ static int tiocgwinsz(struct tty_struct *tty, struct winsize __user *arg) { - int err; + guard(mutex)(&tty->winsize_mutex); - mutex_lock(&tty->winsize_mutex); - err = copy_to_user(arg, &tty->winsize, sizeof(*arg)); - mutex_unlock(&tty->winsize_mutex); + if (copy_to_user(arg, &tty->winsize, sizeof(*arg))) + return -EFAULT; - return err ? -EFAULT : 0; + return 0; } /** - * tty_do_resize - resize event + * tty_do_resize - resize event * @tty: tty being resized * @ws: new dimensions * @@ -2326,10 +2325,10 @@ int tty_do_resize(struct tty_struct *tty, struct winsize *ws) { struct pid *pgrp; - /* Lock the tty */ - mutex_lock(&tty->winsize_mutex); + guard(mutex)(&tty->winsize_mutex); + if (!memcmp(ws, &tty->winsize, sizeof(*ws))) - goto done; + return 0; /* Signal the foreground process group */ pgrp = tty_get_pgrp(tty); @@ -2338,14 +2337,13 @@ int tty_do_resize(struct tty_struct *tty, struct winsize *ws) put_pid(pgrp); tty->winsize = *ws; -done: - mutex_unlock(&tty->winsize_mutex); + return 0; } EXPORT_SYMBOL(tty_do_resize); /** - * tiocswinsz - implement window size set ioctl + * tiocswinsz - implement window size set ioctl * @tty: tty side of tty * @arg: user buffer for result * @@ -2372,7 +2370,7 @@ static int tiocswinsz(struct tty_struct *tty, struct winsize __user *arg) } /** - * tioccons - allow admin to move logical console + * tioccons - allow admin to move logical console * @file: the file to become console * * Allow the administrator to move the redirected console device. @@ -2400,18 +2398,19 @@ static int tioccons(struct file *file) return -EBADF; if (!(file->f_mode & FMODE_CAN_WRITE)) return -EINVAL; - spin_lock(&redirect_lock); - if (redirect) { - spin_unlock(&redirect_lock); + + guard(spinlock)(&redirect_lock); + + if (redirect) return -EBUSY; - } + redirect = get_file(file); - spin_unlock(&redirect_lock); + return 0; } /** - * tiocsetd - set line discipline + * tiocsetd - set line discipline * @tty: tty device * @p: pointer to user data * @@ -2433,7 +2432,7 @@ static int tiocsetd(struct tty_struct *tty, int __user *p) } /** - * tiocgetd - get line discipline + * tiocgetd - get line discipline * @tty: tty device * @p: pointer to user data * @@ -2456,7 +2455,7 @@ static int tiocgetd(struct tty_struct *tty, int __user *p) } /** - * send_break - performed time break + * send_break - performed time break * @tty: device to break on * @duration: timeout in mS * @@ -2474,27 +2473,48 @@ static int send_break(struct tty_struct *tty, unsigned int duration) return 0; if (tty->driver->flags & TTY_DRIVER_HARDWARE_BREAK) - retval = tty->ops->break_ctl(tty, duration); - else { - /* Do the work ourselves */ - if (tty_write_lock(tty, 0) < 0) - return -EINTR; - retval = tty->ops->break_ctl(tty, -1); - if (retval) - goto out; - if (!signal_pending(current)) - msleep_interruptible(duration); + return tty->ops->break_ctl(tty, duration); + + /* Do the work ourselves */ + if (tty_write_lock(tty, false) < 0) + return -EINTR; + + retval = tty->ops->break_ctl(tty, -1); + if (!retval) { + msleep_interruptible(duration); retval = tty->ops->break_ctl(tty, 0); -out: - tty_write_unlock(tty); - if (signal_pending(current)) - retval = -EINTR; + } else if (retval == -EOPNOTSUPP) { + /* some drivers can tell only dynamically */ + retval = 0; } + tty_write_unlock(tty); + + if (signal_pending(current)) + retval = -EINTR; + return retval; } /** - * tty_tiocmget - get modem status + * tty_get_tiocm - get tiocm status register + * @tty: tty device + * + * Obtain the modem status bits from the tty driver if the feature + * is supported. + */ +int tty_get_tiocm(struct tty_struct *tty) +{ + int retval = -ENOTTY; + + if (tty->ops->tiocmget) + retval = tty->ops->tiocmget(tty); + + return retval; +} +EXPORT_SYMBOL_GPL(tty_get_tiocm); + +/** + * tty_tiocmget - get modem status * @tty: tty device * @p: pointer to result * @@ -2505,19 +2525,17 @@ out: */ static int tty_tiocmget(struct tty_struct *tty, int __user *p) { - int retval = -ENOTTY; + int retval; - if (tty->ops->tiocmget) { - retval = tty->ops->tiocmget(tty); + retval = tty_get_tiocm(tty); + if (retval >= 0) + retval = put_user(retval, p); - if (retval >= 0) - retval = put_user(retval, p); - } return retval; } /** - * tty_tiocmset - set modem status + * tty_tiocmset - set modem status * @tty: tty device * @cmd: command - clear bits, set bits or set all * @p: pointer to desired bits @@ -2558,7 +2576,7 @@ static int tty_tiocmset(struct tty_struct *tty, unsigned int cmd, } /** - * tty_get_icount - get tty statistics + * tty_get_icount - get tty statistics * @tty: tty device * @icount: output parameter * @@ -2594,14 +2612,13 @@ static int tty_tiocgicount(struct tty_struct *tty, void __user *arg) static int tty_set_serial(struct tty_struct *tty, struct serial_struct *ss) { - char comm[TASK_COMM_LEN]; int flags; flags = ss->flags & ASYNC_DEPRECATED; if (flags) pr_warn_ratelimited("%s: '%s' is using deprecated serial flags (with no effect): %.8x\n", - __func__, get_task_comm(comm, current), flags); + __func__, current->comm, flags); if (!tty->ops->set_serial) return -ENOTTY; @@ -3001,11 +3018,9 @@ void __do_SAK(struct tty_struct *tty) struct task_struct *g, *p; struct pid *session; int i; - unsigned long flags; - spin_lock_irqsave(&tty->ctrl.lock, flags); - session = get_pid(tty->ctrl.session); - spin_unlock_irqrestore(&tty->ctrl.lock, flags); + scoped_guard(spinlock_irqsave, &tty->ctrl.lock) + session = get_pid(tty->ctrl.session); tty_ldisc_flush(tty); @@ -3020,7 +3035,7 @@ void __do_SAK(struct tty_struct *tty) } while_each_pid_task(session, PIDTYPE_SID, p); /* Now kill any processes that happen to have the tty open */ - do_each_thread(g, p) { + for_each_process_thread(g, p) { if (p->signal->tty == tty) { tty_notice(tty, "SAK: killed process %d (%s): by controlling tty\n", task_pid_nr(p), p->comm); @@ -3028,7 +3043,7 @@ void __do_SAK(struct tty_struct *tty) PIDTYPE_SID); continue; } - task_lock(p); + guard(task_lock)(p); i = iterate_fd(p->files, 0, this_tty, tty); if (i != 0) { tty_notice(tty, "SAK: killed process %d (%s): by fd#%d\n", @@ -3036,8 +3051,7 @@ void __do_SAK(struct tty_struct *tty) group_send_sig_info(SIGKILL, SEND_SIG_PRIV, p, PIDTYPE_SID); } - task_unlock(p); - } while_each_thread(g, p); + } read_unlock(&tasklist_lock); put_pid(session); } @@ -3068,7 +3082,7 @@ static struct device *tty_get_device(struct tty_struct *tty) { dev_t devt = tty_devnum(tty); - return class_find_device_by_devt(tty_class, devt); + return class_find_device_by_devt(&tty_class, devt); } @@ -3121,7 +3135,7 @@ struct tty_struct *alloc_tty_struct(struct tty_driver *driver, int idx) } /** - * tty_put_char - write one character to a tty + * tty_put_char - write one character to a tty * @tty: tty * @ch: character to write * @@ -3133,7 +3147,7 @@ struct tty_struct *alloc_tty_struct(struct tty_driver *driver, int idx) * * Return: the number of characters successfully output. */ -int tty_put_char(struct tty_struct *tty, unsigned char ch) +int tty_put_char(struct tty_struct *tty, u8 ch) { if (tty->ops->put_char) return tty->ops->put_char(tty, ch); @@ -3141,8 +3155,6 @@ int tty_put_char(struct tty_struct *tty, unsigned char ch) } EXPORT_SYMBOL_GPL(tty_put_char); -struct class *tty_class; - static int tty_cdev_add(struct tty_driver *driver, dev_t dev, unsigned int index, unsigned int count) { @@ -3237,7 +3249,7 @@ struct device *tty_register_device_attr(struct tty_driver *driver, return ERR_PTR(-ENOMEM); dev->devt = devt; - dev->class = tty_class; + dev->class = &tty_class; dev->parent = device; dev->release = tty_device_create_release; dev_set_name(dev, "%s", name); @@ -3292,8 +3304,7 @@ EXPORT_SYMBOL_GPL(tty_register_device_attr); */ void tty_unregister_device(struct tty_driver *driver, unsigned index) { - device_destroy(tty_class, - MKDEV(driver->major, driver->minor_start) + index); + device_destroy(&tty_class, MKDEV(driver->major, driver->minor_start) + index); if (!(driver->flags & TTY_DRIVER_DYNAMIC_ALLOC)) { cdev_del(driver->cdevs[index]); driver->cdevs[index] = NULL; @@ -3302,13 +3313,15 @@ void tty_unregister_device(struct tty_driver *driver, unsigned index) EXPORT_SYMBOL(tty_unregister_device); /** - * __tty_alloc_driver -- allocate tty driver + * __tty_alloc_driver - allocate tty driver * @lines: count of lines this driver can handle at most * @owner: module which is responsible for this driver - * @flags: some of %TTY_DRIVER_ flags, will be set in driver->flags + * @flags: some of enum tty_driver_flag, will be set in driver->flags + * + * This should not be called directly, tty_alloc_driver() should be used + * instead. * - * This should not be called directly, some of the provided macros should be - * used instead. Use IS_ERR() and friends on @retval. + * Returns: struct tty_driver or a PTR-encoded error (use IS_ERR() and friends). */ struct tty_driver *__tty_alloc_driver(unsigned int lines, struct module *owner, unsigned long flags) @@ -3395,7 +3408,7 @@ static void destruct_tty_driver(struct kref *kref) } /** - * tty_driver_kref_put -- drop a reference to a tty driver + * tty_driver_kref_put - drop a reference to a tty driver * @driver: driver of which to drop the reference * * The final put will destroy and free up the driver. @@ -3407,7 +3420,7 @@ void tty_driver_kref_put(struct tty_driver *driver) EXPORT_SYMBOL(tty_driver_kref_put); /** - * tty_register_driver -- register a tty driver + * tty_register_driver - register a tty driver * @driver: driver to register * * Called by a tty driver to register itself. @@ -3439,9 +3452,8 @@ int tty_register_driver(struct tty_driver *driver) goto err_unreg_char; } - mutex_lock(&tty_mutex); - list_add(&driver->tty_drivers, &tty_drivers); - mutex_unlock(&tty_mutex); + scoped_guard(mutex, &tty_mutex) + list_add(&driver->tty_drivers, &tty_drivers); if (!(driver->flags & TTY_DRIVER_DYNAMIC_DEV)) { for (i = 0; i < driver->num; i++) { @@ -3460,9 +3472,8 @@ err_unreg_devs: for (i--; i >= 0; i--) tty_unregister_device(driver, i); - mutex_lock(&tty_mutex); - list_del(&driver->tty_drivers); - mutex_unlock(&tty_mutex); + scoped_guard(mutex, &tty_mutex) + list_del(&driver->tty_drivers); err_unreg_char: unregister_chrdev_region(dev, driver->num); @@ -3472,7 +3483,7 @@ err: EXPORT_SYMBOL(tty_register_driver); /** - * tty_unregister_driver -- unregister a tty driver + * tty_unregister_driver - unregister a tty driver * @driver: driver to unregister * * Called by a tty driver to unregister itself. @@ -3481,9 +3492,8 @@ void tty_unregister_driver(struct tty_driver *driver) { unregister_chrdev_region(MKDEV(driver->major, driver->minor_start), driver->num); - mutex_lock(&tty_mutex); - list_del(&driver->tty_drivers); - mutex_unlock(&tty_mutex); + scoped_guard(mutex, &tty_mutex) + list_del(&driver->tty_drivers); } EXPORT_SYMBOL(tty_unregister_driver); @@ -3508,13 +3518,14 @@ static char *tty_devnode(const struct device *dev, umode_t *mode) return NULL; } +const struct class tty_class = { + .name = "tty", + .devnode = tty_devnode, +}; + static int __init tty_class_init(void) { - tty_class = class_create(THIS_MODULE, "tty"); - if (IS_ERR(tty_class)) - return PTR_ERR(tty_class); - tty_class->devnode = tty_devnode; - return 0; + return class_register(&tty_class); } postcore_initcall(tty_class_init); @@ -3541,7 +3552,7 @@ static ssize_t show_cons_active(struct device *dev, for_each_console(c) { if (!c->device) continue; - if (!c->write) + if (!(c->flags & CON_NBCON) && !c->write) continue; if ((c->flags & CON_ENABLED) == 0) continue; @@ -3592,7 +3603,7 @@ void console_sysfs_notify(void) sysfs_notify(&consdev->kobj, NULL, "active"); } -static struct ctl_table tty_table[] = { +static const struct ctl_table tty_table[] = { { .procname = "legacy_tiocsti", .data = &tty_legacy_tiocsti, @@ -3605,29 +3616,10 @@ static struct ctl_table tty_table[] = { .data = &tty_ldisc_autoload, .maxlen = sizeof(tty_ldisc_autoload), .mode = 0644, - .proc_handler = proc_dointvec, + .proc_handler = proc_dointvec_minmax, .extra1 = SYSCTL_ZERO, .extra2 = SYSCTL_ONE, }, - { } -}; - -static struct ctl_table tty_dir_table[] = { - { - .procname = "tty", - .mode = 0555, - .child = tty_table, - }, - { } -}; - -static struct ctl_table tty_root_table[] = { - { - .procname = "dev", - .mode = 0555, - .child = tty_dir_table, - }, - { } }; /* @@ -3636,18 +3628,18 @@ static struct ctl_table tty_root_table[] = { */ int __init tty_init(void) { - register_sysctl_table(tty_root_table); + register_sysctl_init("dev/tty", tty_table); 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"); - device_create(tty_class, NULL, MKDEV(TTYAUX_MAJOR, 0), NULL, "tty"); + 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"); - consdev = device_create_with_groups(tty_class, NULL, + consdev = device_create_with_groups(&tty_class, NULL, MKDEV(TTYAUX_MAJOR, 1), NULL, cons_dev_groups, "console"); if (IS_ERR(consdev)) |