diff options
Diffstat (limited to 'drivers/tty/tty_ioctl.c')
| -rw-r--r-- | drivers/tty/tty_ioctl.c | 985 |
1 files changed, 372 insertions, 613 deletions
diff --git a/drivers/tty/tty_ioctl.c b/drivers/tty/tty_ioctl.c index 3500d4114147..90c70d8d14e3 100644 --- a/drivers/tty/tty_ioctl.c +++ b/drivers/tty/tty_ioctl.c @@ -1,3 +1,4 @@ +// SPDX-License-Identifier: GPL-2.0 /* * Copyright (C) 1991, 1992, 1993, 1994 Linus Torvalds * @@ -6,10 +7,11 @@ * discipline handling modules (like SLIP). */ +#include <linux/bits.h> #include <linux/types.h> #include <linux/termios.h> #include <linux/errno.h> -#include <linux/sched.h> +#include <linux/sched/signal.h> #include <linux/kernel.h> #include <linux/major.h> #include <linux/tty.h> @@ -20,53 +22,48 @@ #include <linux/bitops.h> #include <linux/mutex.h> #include <linux/compat.h> +#include <linux/termios_internal.h> +#include "tty.h" #include <asm/io.h> -#include <asm/uaccess.h> - -#undef TTY_DEBUG_WAIT_UNTIL_SENT +#include <linux/uaccess.h> #undef DEBUG /* * Internal flag options for termios setting behavior */ -#define TERMIOS_FLUSH 1 -#define TERMIOS_WAIT 2 -#define TERMIOS_TERMIO 4 -#define TERMIOS_OLD 8 - +#define TERMIOS_FLUSH BIT(0) +#define TERMIOS_WAIT BIT(1) +#define TERMIOS_TERMIO BIT(2) +#define TERMIOS_OLD BIT(3) /** - * tty_chars_in_buffer - characters pending - * @tty: terminal + * tty_chars_in_buffer - characters pending + * @tty: terminal * - * Return the number of bytes of data in the device private - * output queue. If no private method is supplied there is assumed - * to be no queue on the device. + * Returns: the number of bytes of data in the device private output queue. If + * no private method is supplied there is assumed to be no queue on the device. */ - -int tty_chars_in_buffer(struct tty_struct *tty) +unsigned int tty_chars_in_buffer(struct tty_struct *tty) { if (tty->ops->chars_in_buffer) return tty->ops->chars_in_buffer(tty); - else - return 0; + return 0; } EXPORT_SYMBOL(tty_chars_in_buffer); /** - * tty_write_room - write queue space - * @tty: terminal - * - * Return the number of bytes that can be queued to this device - * at the present time. The result should be treated as a guarantee - * and the driver cannot offer a value it later shrinks by more than - * the number of bytes written. If no method is provided 2K is always - * returned and data may be lost as there will be no flow control. + * tty_write_room - write queue space + * @tty: terminal + * + * Returns: the number of bytes that can be queued to this device at the present + * time. The result should be treated as a guarantee and the driver cannot + * offer a value it later shrinks by more than the number of bytes written. If + * no method is provided, 2K is always returned and data may be lost as there + * will be no flow control. */ - -int tty_write_room(struct tty_struct *tty) +unsigned int tty_write_room(struct tty_struct *tty) { if (tty->ops->write_room) return tty->ops->write_room(tty); @@ -75,12 +72,12 @@ int tty_write_room(struct tty_struct *tty) EXPORT_SYMBOL(tty_write_room); /** - * tty_driver_flush_buffer - discard internal buffer - * @tty: terminal + * tty_driver_flush_buffer - discard internal buffer + * @tty: terminal * - * Discard the internal output buffer for this device. If no method - * is provided then either the buffer cannot be hardware flushed or - * there is no buffer driver side. + * Discard the internal output buffer for this device. If no method is provided, + * then either the buffer cannot be hardware flushed or there is no buffer + * driver side. */ void tty_driver_flush_buffer(struct tty_struct *tty) { @@ -90,138 +87,110 @@ void tty_driver_flush_buffer(struct tty_struct *tty) EXPORT_SYMBOL(tty_driver_flush_buffer); /** - * tty_throttle - flow control - * @tty: terminal - * - * Indicate that a tty should stop transmitting data down the stack. - * Takes the termios mutex to protect against parallel throttle/unthrottle - * and also to ensure the driver can consistently reference its own - * termios data at this point when implementing software flow control. - */ - -void tty_throttle(struct tty_struct *tty) -{ - mutex_lock(&tty->termios_mutex); - /* check TTY_THROTTLED first so it indicates our state */ - if (!test_and_set_bit(TTY_THROTTLED, &tty->flags) && - tty->ops->throttle) - tty->ops->throttle(tty); - tty->flow_change = 0; - mutex_unlock(&tty->termios_mutex); -} -EXPORT_SYMBOL(tty_throttle); - -/** - * tty_unthrottle - flow control - * @tty: terminal + * tty_unthrottle - flow control + * @tty: terminal * - * Indicate that a tty may continue transmitting data down the stack. - * Takes the termios mutex to protect against parallel throttle/unthrottle - * and also to ensure the driver can consistently reference its own - * termios data at this point when implementing software flow control. + * Indicate that a @tty may continue transmitting data down the stack. Takes + * the &tty_struct->termios_rwsem to protect against parallel + * throttle/unthrottle and also to ensure the driver can consistently reference + * its own termios data at this point when implementing software flow control. * - * Drivers should however remember that the stack can issue a throttle, - * then change flow control method, then unthrottle. + * Drivers should however remember that the stack can issue a throttle, then + * change flow control method, then unthrottle. */ - void tty_unthrottle(struct tty_struct *tty) { - mutex_lock(&tty->termios_mutex); + down_write(&tty->termios_rwsem); if (test_and_clear_bit(TTY_THROTTLED, &tty->flags) && tty->ops->unthrottle) tty->ops->unthrottle(tty); - tty->flow_change = 0; - mutex_unlock(&tty->termios_mutex); + tty->flow_change = TTY_FLOW_NO_CHANGE; + up_write(&tty->termios_rwsem); } EXPORT_SYMBOL(tty_unthrottle); /** - * tty_throttle_safe - flow control - * @tty: terminal + * tty_throttle_safe - flow control + * @tty: terminal * - * Similar to tty_throttle() but will only attempt throttle - * if tty->flow_change is TTY_THROTTLE_SAFE. Prevents an accidental - * throttle due to race conditions when throttling is conditional - * on factors evaluated prior to throttling. + * Indicate that a @tty should stop transmitting data down the stack. + * tty_throttle_safe() will only attempt throttle if @tty->flow_change is + * %TTY_THROTTLE_SAFE. Prevents an accidental throttle due to race conditions + * when throttling is conditional on factors evaluated prior to throttling. * - * Returns 0 if tty is throttled (or was already throttled) + * Returns: %true if @tty is throttled (or was already throttled) */ - -int tty_throttle_safe(struct tty_struct *tty) +bool tty_throttle_safe(struct tty_struct *tty) { - int ret = 0; + guard(mutex)(&tty->throttle_mutex); - mutex_lock(&tty->termios_mutex); - if (!test_bit(TTY_THROTTLED, &tty->flags)) { - if (tty->flow_change != TTY_THROTTLE_SAFE) - ret = 1; - else { - set_bit(TTY_THROTTLED, &tty->flags); - if (tty->ops->throttle) - tty->ops->throttle(tty); - } - } - mutex_unlock(&tty->termios_mutex); + if (tty_throttled(tty)) + return true; - return ret; + if (tty->flow_change != TTY_THROTTLE_SAFE) + return false; + + set_bit(TTY_THROTTLED, &tty->flags); + if (tty->ops->throttle) + tty->ops->throttle(tty); + + return true; } /** - * tty_unthrottle_safe - flow control - * @tty: terminal + * tty_unthrottle_safe - flow control + * @tty: terminal * - * Similar to tty_unthrottle() but will only attempt unthrottle - * if tty->flow_change is TTY_UNTHROTTLE_SAFE. Prevents an accidental - * unthrottle due to race conditions when unthrottling is conditional - * on factors evaluated prior to unthrottling. + * Similar to tty_unthrottle() but will only attempt unthrottle if + * @tty->flow_change is %TTY_UNTHROTTLE_SAFE. Prevents an accidental unthrottle + * due to race conditions when unthrottling is conditional on factors evaluated + * prior to unthrottling. * - * Returns 0 if tty is unthrottled (or was already unthrottled) + * Returns: %true if @tty is unthrottled (or was already unthrottled) */ - -int tty_unthrottle_safe(struct tty_struct *tty) +bool tty_unthrottle_safe(struct tty_struct *tty) { - int ret = 0; + guard(mutex)(&tty->throttle_mutex); - mutex_lock(&tty->termios_mutex); - if (test_bit(TTY_THROTTLED, &tty->flags)) { - if (tty->flow_change != TTY_UNTHROTTLE_SAFE) - ret = 1; - else { - clear_bit(TTY_THROTTLED, &tty->flags); - if (tty->ops->unthrottle) - tty->ops->unthrottle(tty); - } - } - mutex_unlock(&tty->termios_mutex); + if (!tty_throttled(tty)) + return true; - return ret; + if (tty->flow_change != TTY_UNTHROTTLE_SAFE) + return false; + + clear_bit(TTY_THROTTLED, &tty->flags); + if (tty->ops->unthrottle) + tty->ops->unthrottle(tty); + + return true; } /** - * tty_wait_until_sent - wait for I/O to finish - * @tty: tty we are waiting for - * @timeout: how long we will wait + * tty_wait_until_sent - wait for I/O to finish + * @tty: tty we are waiting for + * @timeout: how long we will wait * - * Wait for characters pending in a tty driver to hit the wire, or - * for a timeout to occur (eg due to flow control) + * Wait for characters pending in a tty driver to hit the wire, or for a + * timeout to occur (eg due to flow control). * - * Locking: none + * Locking: none */ void tty_wait_until_sent(struct tty_struct *tty, long timeout) { -#ifdef TTY_DEBUG_WAIT_UNTIL_SENT - char buf[64]; - - printk(KERN_DEBUG "%s wait until sent...\n", tty_name(tty, buf)); -#endif if (!timeout) timeout = MAX_SCHEDULE_TIMEOUT; - if (wait_event_interruptible_timeout(tty->write_wait, - !tty_chars_in_buffer(tty), timeout) >= 0) { - if (tty->ops->wait_until_sent) - tty->ops->wait_until_sent(tty, timeout); - } + + timeout = wait_event_interruptible_timeout(tty->write_wait, + !tty_chars_in_buffer(tty), timeout); + if (timeout <= 0) + return; + + if (timeout == MAX_SCHEDULE_TIMEOUT) + timeout = 0; + + if (tty->ops->wait_until_sent) + tty->ops->wait_until_sent(tty, timeout); } EXPORT_SYMBOL(tty_wait_until_sent); @@ -230,19 +199,14 @@ EXPORT_SYMBOL(tty_wait_until_sent); * Termios Helper Methods */ -static void unset_locked_termios(struct ktermios *termios, - struct ktermios *old, - struct ktermios *locked) +static void unset_locked_termios(struct tty_struct *tty, const struct ktermios *old) { + struct ktermios *termios = &tty->termios; + struct ktermios *locked = &tty->termios_locked; int i; #define NOSET_MASK(x, y, z) (x = ((x) & ~(z)) | ((y) & (z))) - if (!locked) { - printk(KERN_WARNING "Warning?!? termios_locked is NULL.\n"); - return; - } - NOSET_MASK(termios->c_iflag, old->c_iflag, locked->c_iflag); NOSET_MASK(termios->c_oflag, old->c_oflag, locked->c_oflag); NOSET_MASK(termios->c_cflag, old->c_cflag, locked->c_cflag); @@ -254,289 +218,111 @@ static void unset_locked_termios(struct ktermios *termios, /* FIXME: What should we do for i/ospeed */ } -/* - * 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 const speed_t 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 -}; - -#ifndef __sparc__ -static const tcflag_t baud_bits[] = { - B0, B50, B75, B110, B134, B150, B200, B300, B600, - B1200, B1800, B2400, B4800, B9600, B19200, B38400, - B57600, B115200, B230400, B460800, B500000, B576000, - B921600, B1000000, B1152000, B1500000, B2000000, B2500000, - B3000000, B3500000, B4000000 -}; -#else -static const tcflag_t baud_bits[] = { - B0, B50, B75, B110, B134, B150, B200, B300, B600, - B1200, B1800, B2400, B4800, B9600, B19200, B38400, - B57600, B115200, B230400, B460800, B76800, B153600, - B307200, B614400, B921600 -}; -#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. Device drivers can call this - * function but should use ->c_[io]speed directly as they are updated. - * - * Locking: none + * tty_termios_copy_hw - copy hardware settings + * @new: new termios + * @old: old termios + * + * Propagate the hardware specific terminal setting bits from the @old termios + * structure to the @new one. This is used in cases where the hardware does not + * support reconfiguration or as a helper in some cases where only minimal + * reconfiguration is supported. */ - -speed_t tty_termios_baud_rate(struct ktermios *termios) +void tty_termios_copy_hw(struct ktermios *new, const struct ktermios *old) { - unsigned int cbaud; - - cbaud = termios->c_cflag & CBAUD; - -#ifdef BOTHER - /* Magic token for arbitrary speed via c_ispeed/c_ospeed */ - if (cbaud == BOTHER) - return termios->c_ospeed; -#endif - if (cbaud & CBAUDEX) { - cbaud &= ~CBAUDEX; - - if (cbaud < 1 || cbaud + 15 > n_baud_table) - termios->c_cflag &= ~CBAUDEX; - else - cbaud += 15; - } - return baud_table[cbaud]; + /* The bits a dumb device handles in software. Smart devices need + to always provide a set_termios method */ + new->c_cflag &= HUPCL | CREAD | CLOCAL; + new->c_cflag |= old->c_cflag & ~(HUPCL | CREAD | CLOCAL); + new->c_ispeed = old->c_ispeed; + new->c_ospeed = old->c_ospeed; } -EXPORT_SYMBOL(tty_termios_baud_rate); +EXPORT_SYMBOL(tty_termios_copy_hw); /** - * tty_termios_input_baud_rate - * @termios: termios structure + * tty_termios_hw_change - check for setting change + * @a: termios + * @b: termios to compare * - * 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. Device drivers can call this - * function but should use ->c_[io]speed directly as they are updated. + * Check if any of the bits that affect a dumb device have changed between the + * two termios structures, or a speed change is needed. * - * Locking: none + * Returns: %true if change is needed */ - -speed_t tty_termios_input_baud_rate(struct ktermios *termios) +bool tty_termios_hw_change(const struct ktermios *a, const struct ktermios *b) { -#ifdef IBSHIFT - unsigned int cbaud = (termios->c_cflag >> IBSHIFT) & CBAUD; - - if (cbaud == B0) - return tty_termios_baud_rate(termios); - - /* Magic token for arbitrary speed via c_ispeed*/ - if (cbaud == BOTHER) - return termios->c_ispeed; - - if (cbaud & CBAUDEX) { - cbaud &= ~CBAUDEX; - - if (cbaud < 1 || cbaud + 15 > n_baud_table) - termios->c_cflag &= ~(CBAUDEX << IBSHIFT); - else - cbaud += 15; - } - return baud_table[cbaud]; -#else - return tty_termios_baud_rate(termios); -#endif + if (a->c_ispeed != b->c_ispeed || a->c_ospeed != b->c_ospeed) + return true; + if ((a->c_cflag ^ b->c_cflag) & ~(HUPCL | CREAD | CLOCAL)) + return true; + return false; } -EXPORT_SYMBOL(tty_termios_input_baud_rate); +EXPORT_SYMBOL(tty_termios_hw_change); /** - * tty_termios_encode_baud_rate - * @termios: ktermios structure holding user requested state - * @ispeed: input speed - * @ospeed: output speed - * - * Encode the speeds set into the passed termios structure. This is - * used as a library helper for drivers so that they can report back - * the actual speed selected when it differs from the speed requested + * tty_get_char_size - get size of a character + * @cflag: termios cflag value * - * For maximal back compatibility with legacy SYS5/POSIX *nix behaviour - * we need to carefully set the bits when the user does not get the - * desired speed. We allow small margins and preserve as much of possible - * of the input intent to keep compatibility. - * - * Locking: Caller should hold termios lock. This is already held - * when calling this function from the driver termios handler. - * - * The ifdefs deal with platforms whose owners have yet to update them - * and will all go away once this is done. + * Returns: size (in bits) of a character depending on @cflag's %CSIZE setting */ - -void tty_termios_encode_baud_rate(struct ktermios *termios, - speed_t ibaud, speed_t obaud) -{ - int i = 0; - int ifound = -1, ofound = -1; - int iclose = ibaud/50, oclose = obaud/50; - int ibinput = 0; - - if (obaud == 0) /* CD dropped */ - ibaud = 0; /* Clear ibaud to be sure */ - - termios->c_ispeed = ibaud; - termios->c_ospeed = obaud; - -#ifdef BOTHER - /* If the user asked for a precise weird speed give a precise weird - answer. If they asked for a Bfoo speed they many have problems - digesting non-exact replies so fuzz a bit */ - - if ((termios->c_cflag & CBAUD) == BOTHER) - oclose = 0; - if (((termios->c_cflag >> IBSHIFT) & CBAUD) == BOTHER) - iclose = 0; - if ((termios->c_cflag >> IBSHIFT) & CBAUD) - ibinput = 1; /* An input speed was specified */ -#endif - termios->c_cflag &= ~CBAUD; - - /* - * Our goal is to find a close match to the standard baud rate - * returned. Walk the baud rate table and if we get a very close - * match then report back the speed as a POSIX Bxxxx value by - * preference - */ - - do { - if (obaud - oclose <= baud_table[i] && - obaud + oclose >= baud_table[i]) { - termios->c_cflag |= baud_bits[i]; - ofound = i; - } - if (ibaud - iclose <= baud_table[i] && - ibaud + iclose >= baud_table[i]) { - /* For the case input == output don't set IBAUD bits - if the user didn't do so */ - if (ofound == i && !ibinput) - ifound = i; -#ifdef IBSHIFT - else { - ifound = i; - termios->c_cflag |= (baud_bits[i] << IBSHIFT); - } -#endif - } - } while (++i < n_baud_table); - - /* - * If we found no match then use BOTHER if provided or warn - * the user their platform maintainer needs to wake up if not. - */ -#ifdef BOTHER - if (ofound == -1) - termios->c_cflag |= BOTHER; - /* Set exact input bits only if the input and output differ or the - user already did */ - if (ifound == -1 && (ibaud != obaud || ibinput)) - termios->c_cflag |= (BOTHER << IBSHIFT); -#else - if (ifound == -1 || ofound == -1) { - printk_once(KERN_WARNING "tty: Unable to return correct " - "speed data as your architecture needs updating.\n"); +unsigned char tty_get_char_size(unsigned int cflag) +{ + switch (cflag & CSIZE) { + case CS5: + return 5; + case CS6: + return 6; + case CS7: + return 7; + case CS8: + default: + return 8; } -#endif } -EXPORT_SYMBOL_GPL(tty_termios_encode_baud_rate); +EXPORT_SYMBOL_GPL(tty_get_char_size); /** - * tty_encode_baud_rate - set baud rate of the tty - * @ibaud: input baud rate - * @obad: output baud rate + * tty_get_frame_size - get size of a frame + * @cflag: termios cflag value * - * Update the current termios data for the tty with the new speed - * settings. The caller must hold the termios_mutex for the tty in - * question. - */ - -void tty_encode_baud_rate(struct tty_struct *tty, speed_t ibaud, speed_t obaud) -{ - tty_termios_encode_baud_rate(&tty->termios, ibaud, obaud); -} -EXPORT_SYMBOL_GPL(tty_encode_baud_rate); - -/** - * tty_termios_copy_hw - copy hardware settings - * @new: New termios - * @old: Old termios + * Get the size (in bits) of a frame depending on @cflag's %CSIZE, %CSTOPB, and + * %PARENB setting. The result is a sum of character size, start and stop bits + * -- one bit each -- second stop bit (if set), and parity bit (if set). * - * Propagate the hardware specific terminal setting bits from - * the old termios structure to the new one. This is used in cases - * where the hardware does not support reconfiguration or as a helper - * in some cases where only minimal reconfiguration is supported + * Returns: size (in bits) of a frame depending on @cflag's setting. */ - -void tty_termios_copy_hw(struct ktermios *new, struct ktermios *old) +unsigned char tty_get_frame_size(unsigned int cflag) { - /* The bits a dumb device handles in software. Smart devices need - to always provide a set_termios method */ - new->c_cflag &= HUPCL | CREAD | CLOCAL; - new->c_cflag |= old->c_cflag & ~(HUPCL | CREAD | CLOCAL); - new->c_ispeed = old->c_ispeed; - new->c_ospeed = old->c_ospeed; -} -EXPORT_SYMBOL(tty_termios_copy_hw); + unsigned char bits = 2 + tty_get_char_size(cflag); -/** - * tty_termios_hw_change - check for setting change - * @a: termios - * @b: termios to compare - * - * Check if any of the bits that affect a dumb device have changed - * between the two termios structures, or a speed change is needed. - */ + if (cflag & CSTOPB) + bits++; + if (cflag & PARENB) + bits++; + if (cflag & ADDRB) + bits++; -int tty_termios_hw_change(struct ktermios *a, struct ktermios *b) -{ - if (a->c_ispeed != b->c_ispeed || a->c_ospeed != b->c_ospeed) - return 1; - if ((a->c_cflag ^ b->c_cflag) & ~(HUPCL | CREAD | CLOCAL)) - return 1; - return 0; + return bits; } -EXPORT_SYMBOL(tty_termios_hw_change); +EXPORT_SYMBOL_GPL(tty_get_frame_size); /** - * tty_set_termios - update termios values - * @tty: tty to update - * @new_termios: desired new value + * tty_set_termios - update termios values + * @tty: tty to update + * @new_termios: desired new value * - * Perform updates to the termios values set on this terminal. There - * is a bit of layering violation here with n_tty in terms of the - * internal knowledge of this function. + * Perform updates to the termios values set on this @tty. A master pty's + * termios should never be set. * - * Locking: termios_mutex + * Locking: &tty_struct->termios_rwsem */ - int tty_set_termios(struct tty_struct *tty, struct ktermios *new_termios) { struct ktermios old_termios; struct tty_ldisc *ld; - unsigned long flags; + WARN_ON(tty->driver->type == TTY_DRIVER_TYPE_PTY && + tty->driver->subtype == PTY_TYPE_MASTER); /* * Perform the actual termios internal changes under lock. */ @@ -544,66 +330,117 @@ int tty_set_termios(struct tty_struct *tty, struct ktermios *new_termios) /* FIXME: we need to decide on some locking/ordering semantics for the set_termios notification eventually */ - mutex_lock(&tty->termios_mutex); + down_write(&tty->termios_rwsem); old_termios = tty->termios; tty->termios = *new_termios; - unset_locked_termios(&tty->termios, &old_termios, &tty->termios_locked); - - /* See if packet mode change of state. */ - if (tty->link && tty->link->packet) { - int extproc = (old_termios.c_lflag & EXTPROC) | - (tty->termios.c_lflag & EXTPROC); - int old_flow = ((old_termios.c_iflag & IXON) && - (old_termios.c_cc[VSTOP] == '\023') && - (old_termios.c_cc[VSTART] == '\021')); - int new_flow = (I_IXON(tty) && - STOP_CHAR(tty) == '\023' && - START_CHAR(tty) == '\021'); - if ((old_flow != new_flow) || extproc) { - spin_lock_irqsave(&tty->ctrl_lock, flags); - if (old_flow != new_flow) { - tty->ctrl_status &= ~(TIOCPKT_DOSTOP | TIOCPKT_NOSTOP); - if (new_flow) - tty->ctrl_status |= TIOCPKT_DOSTOP; - else - tty->ctrl_status |= TIOCPKT_NOSTOP; - } - if (extproc) - tty->ctrl_status |= TIOCPKT_IOCTL; - spin_unlock_irqrestore(&tty->ctrl_lock, flags); - wake_up_interruptible(&tty->link->read_wait); - } - } + unset_locked_termios(tty, &old_termios); + /* Reset any ADDRB changes, ADDRB is changed through ->rs485_config() */ + tty->termios.c_cflag ^= (tty->termios.c_cflag ^ old_termios.c_cflag) & ADDRB; if (tty->ops->set_termios) - (*tty->ops->set_termios)(tty, &old_termios); + tty->ops->set_termios(tty, &old_termios); else tty_termios_copy_hw(&tty->termios, &old_termios); ld = tty_ldisc_ref(tty); if (ld != NULL) { if (ld->ops->set_termios) - (ld->ops->set_termios)(tty, &old_termios); + ld->ops->set_termios(tty, &old_termios); tty_ldisc_deref(ld); } - mutex_unlock(&tty->termios_mutex); + up_write(&tty->termios_rwsem); return 0; } EXPORT_SYMBOL_GPL(tty_set_termios); + +/* + * Translate a "termio" structure into a "termios". Ugh. + */ +__weak int user_termio_to_kernel_termios(struct ktermios *termios, + struct termio __user *termio) +{ + struct termio v; + + if (copy_from_user(&v, termio, sizeof(struct termio))) + return -EFAULT; + + termios->c_iflag = (0xffff0000 & termios->c_iflag) | v.c_iflag; + termios->c_oflag = (0xffff0000 & termios->c_oflag) | v.c_oflag; + termios->c_cflag = (0xffff0000 & termios->c_cflag) | v.c_cflag; + termios->c_lflag = (0xffff0000 & termios->c_lflag) | v.c_lflag; + termios->c_line = (0xffff0000 & termios->c_lflag) | v.c_line; + memcpy(termios->c_cc, v.c_cc, NCC); + return 0; +} + +/* + * Translate a "termios" structure into a "termio". Ugh. + */ +__weak int kernel_termios_to_user_termio(struct termio __user *termio, + struct ktermios *termios) +{ + struct termio v; + memset(&v, 0, sizeof(struct termio)); + v.c_iflag = termios->c_iflag; + v.c_oflag = termios->c_oflag; + v.c_cflag = termios->c_cflag; + v.c_lflag = termios->c_lflag; + v.c_line = termios->c_line; + memcpy(v.c_cc, termios->c_cc, NCC); + return copy_to_user(termio, &v, sizeof(struct termio)); +} + +#ifdef TCGETS2 +__weak int user_termios_to_kernel_termios(struct ktermios *k, + struct termios2 __user *u) +{ + return copy_from_user(k, u, sizeof(struct termios2)); +} +__weak int kernel_termios_to_user_termios(struct termios2 __user *u, + struct ktermios *k) +{ + return copy_to_user(u, k, sizeof(struct termios2)); +} +__weak int user_termios_to_kernel_termios_1(struct ktermios *k, + struct termios __user *u) +{ + return copy_from_user(k, u, sizeof(struct termios)); +} +__weak int kernel_termios_to_user_termios_1(struct termios __user *u, + struct ktermios *k) +{ + return copy_to_user(u, k, sizeof(struct termios)); +} + +#else + +__weak int user_termios_to_kernel_termios(struct ktermios *k, + struct termios __user *u) +{ + return copy_from_user(k, u, sizeof(struct termios)); +} +__weak int kernel_termios_to_user_termios(struct termios __user *u, + struct ktermios *k) +{ + return copy_to_user(u, k, sizeof(struct termios)); +} +#endif /* TCGETS2 */ + /** - * set_termios - set termios values for a tty - * @tty: terminal device - * @arg: user data - * @opt: option information + * set_termios - set termios values for a tty + * @tty: terminal device + * @arg: user data + * @opt: option information * - * Helper function to prepare termios data and run necessary other - * functions before using tty_set_termios to do the actual changes. + * Helper function to prepare termios data and run necessary other functions + * before using tty_set_termios() to do the actual changes. * - * Locking: - * Called functions take ldisc and termios_mutex locks + * Locking: called functions take &tty_struct->ldisc_sem and + * &tty_struct->termios_rwsem locks + * + * Returns: 0 on success, an error otherwise */ - static int set_termios(struct tty_struct *tty, void __user *arg, int opt) { struct ktermios tmp_termios; @@ -613,9 +450,9 @@ static int set_termios(struct tty_struct *tty, void __user *arg, int opt) if (retval) return retval; - mutex_lock(&tty->termios_mutex); + down_read(&tty->termios_rwsem); tmp_termios = tty->termios; - mutex_unlock(&tty->termios_mutex); + up_read(&tty->termios_rwsem); if (opt & TERMIOS_TERMIO) { if (user_termio_to_kernel_termios(&tmp_termios, @@ -642,21 +479,42 @@ static int set_termios(struct tty_struct *tty, void __user *arg, int opt) tmp_termios.c_ispeed = tty_termios_input_baud_rate(&tmp_termios); tmp_termios.c_ospeed = tty_termios_baud_rate(&tmp_termios); - ld = tty_ldisc_ref(tty); + if (opt & (TERMIOS_FLUSH|TERMIOS_WAIT)) { +retry_write_wait: + retval = wait_event_interruptible(tty->write_wait, !tty_chars_in_buffer(tty)); + if (retval < 0) + return retval; - if (ld != NULL) { - if ((opt & TERMIOS_FLUSH) && ld->ops->flush_buffer) - ld->ops->flush_buffer(tty); - tty_ldisc_deref(ld); - } + if (tty_write_lock(tty, false) < 0) + goto retry_write_wait; - if (opt & TERMIOS_WAIT) { - tty_wait_until_sent(tty, 0); - if (signal_pending(current)) - return -ERESTARTSYS; - } + /* Racing writer? */ + if (tty_chars_in_buffer(tty)) { + tty_write_unlock(tty); + goto retry_write_wait; + } + + ld = tty_ldisc_ref(tty); + if (ld != NULL) { + if ((opt & TERMIOS_FLUSH) && ld->ops->flush_buffer) + ld->ops->flush_buffer(tty); + tty_ldisc_deref(ld); + } + + if ((opt & TERMIOS_WAIT) && tty->ops->wait_until_sent) { + tty->ops->wait_until_sent(tty, 0); + if (signal_pending(current)) { + tty_write_unlock(tty); + return -ERESTARTSYS; + } + } - tty_set_termios(tty, &tmp_termios); + tty_set_termios(tty, &tmp_termios); + + tty_write_unlock(tty); + } else { + tty_set_termios(tty, &tmp_termios); + } /* FIXME: Arguably if tmp_termios == tty->termios AND the actual requested termios was not tmp_termios then we may @@ -667,16 +525,16 @@ static int set_termios(struct tty_struct *tty, void __user *arg, int opt) static void copy_termios(struct tty_struct *tty, struct ktermios *kterm) { - mutex_lock(&tty->termios_mutex); + down_read(&tty->termios_rwsem); *kterm = tty->termios; - mutex_unlock(&tty->termios_mutex); + up_read(&tty->termios_rwsem); } static void copy_termios_locked(struct tty_struct *tty, struct ktermios *kterm) { - mutex_lock(&tty->termios_mutex); + down_read(&tty->termios_rwsem); *kterm = tty->termios_locked; - mutex_unlock(&tty->termios_mutex); + up_read(&tty->termios_rwsem); } static int get_termio(struct tty_struct *tty, struct termio __user *termio) @@ -688,51 +546,6 @@ static int get_termio(struct tty_struct *tty, struct termio __user *termio) return 0; } - -#ifdef TCGETX - -/** - * set_termiox - set termiox fields if possible - * @tty: terminal - * @arg: termiox structure from user - * @opt: option flags for ioctl type - * - * Implement the device calling points for the SYS5 termiox ioctl - * interface in Linux - */ - -static int set_termiox(struct tty_struct *tty, void __user *arg, int opt) -{ - struct termiox tnew; - struct tty_ldisc *ld; - - if (tty->termiox == NULL) - return -EINVAL; - if (copy_from_user(&tnew, arg, sizeof(struct termiox))) - return -EFAULT; - - ld = tty_ldisc_ref(tty); - if (ld != NULL) { - if ((opt & TERMIOS_FLUSH) && ld->ops->flush_buffer) - ld->ops->flush_buffer(tty); - tty_ldisc_deref(ld); - } - if (opt & TERMIOS_WAIT) { - tty_wait_until_sent(tty, 0); - if (signal_pending(current)) - return -ERESTARTSYS; - } - - mutex_lock(&tty->termios_mutex); - if (tty->ops->set_termiox) - tty->ops->set_termiox(tty, &tnew); - mutex_unlock(&tty->termios_mutex); - return 0; -} - -#endif - - #ifdef TIOCGETP /* * These are deprecated, but there is limited support.. @@ -743,16 +556,16 @@ static int get_sgflags(struct tty_struct *tty) { int flags = 0; - if (!(tty->termios.c_lflag & ICANON)) { - if (tty->termios.c_lflag & ISIG) + if (!L_ICANON(tty)) { + if (L_ISIG(tty)) flags |= 0x02; /* cbreak */ else flags |= 0x20; /* raw */ } - if (tty->termios.c_lflag & ECHO) + if (L_ECHO(tty)) flags |= 0x08; /* echo */ - if (tty->termios.c_oflag & OPOST) - if (tty->termios.c_oflag & ONLCR) + if (O_OPOST(tty)) + if (O_ONLCR(tty)) flags |= 0x10; /* crmod */ return flags; } @@ -761,13 +574,13 @@ static int get_sgttyb(struct tty_struct *tty, struct sgttyb __user *sgttyb) { struct sgttyb tmp; - mutex_lock(&tty->termios_mutex); + down_read(&tty->termios_rwsem); tmp.sg_ispeed = tty->termios.c_ispeed; tmp.sg_ospeed = tty->termios.c_ospeed; tmp.sg_erase = tty->termios.c_cc[VERASE]; tmp.sg_kill = tty->termios.c_cc[VKILL]; tmp.sg_flags = get_sgflags(tty); - mutex_unlock(&tty->termios_mutex); + up_read(&tty->termios_rwsem); return copy_to_user(sgttyb, &tmp, sizeof(tmp)) ? -EFAULT : 0; } @@ -799,16 +612,16 @@ static void set_sgflags(struct ktermios *termios, int flags) } /** - * set_sgttyb - set legacy terminal values - * @tty: tty structure - * @sgttyb: pointer to old style terminal structure + * set_sgttyb - set legacy terminal values + * @tty: tty structure + * @sgttyb: pointer to old style terminal structure + * + * Updates a terminal from the legacy BSD style terminal information structure. * - * Updates a terminal from the legacy BSD style terminal information - * structure. + * Locking: &tty_struct->termios_rwsem * - * Locking: termios_mutex + * Returns: 0 on success, an error otherwise */ - static int set_sgttyb(struct tty_struct *tty, struct sgttyb __user *sgttyb) { int retval; @@ -822,17 +635,15 @@ static int set_sgttyb(struct tty_struct *tty, struct sgttyb __user *sgttyb) if (copy_from_user(&tmp, sgttyb, sizeof(tmp))) return -EFAULT; - mutex_lock(&tty->termios_mutex); + down_write(&tty->termios_rwsem); termios = tty->termios; termios.c_cc[VERASE] = tmp.sg_erase; termios.c_cc[VKILL] = tmp.sg_kill; set_sgflags(&termios, tmp.sg_flags); /* Try and encode into Bfoo format */ -#ifdef BOTHER tty_termios_encode_baud_rate(&termios, termios.c_ispeed, termios.c_ospeed); -#endif - mutex_unlock(&tty->termios_mutex); + up_write(&tty->termios_rwsem); tty_set_termios(tty, &termios); return 0; } @@ -843,14 +654,14 @@ static int get_tchars(struct tty_struct *tty, struct tchars __user *tchars) { struct tchars tmp; - mutex_lock(&tty->termios_mutex); + down_read(&tty->termios_rwsem); tmp.t_intrc = tty->termios.c_cc[VINTR]; tmp.t_quitc = tty->termios.c_cc[VQUIT]; tmp.t_startc = tty->termios.c_cc[VSTART]; tmp.t_stopc = tty->termios.c_cc[VSTOP]; tmp.t_eofc = tty->termios.c_cc[VEOF]; tmp.t_brkc = tty->termios.c_cc[VEOL2]; /* what is brkc anyway? */ - mutex_unlock(&tty->termios_mutex); + up_read(&tty->termios_rwsem); return copy_to_user(tchars, &tmp, sizeof(tmp)) ? -EFAULT : 0; } @@ -860,14 +671,14 @@ static int set_tchars(struct tty_struct *tty, struct tchars __user *tchars) if (copy_from_user(&tmp, tchars, sizeof(tmp))) return -EFAULT; - mutex_lock(&tty->termios_mutex); + down_write(&tty->termios_rwsem); tty->termios.c_cc[VINTR] = tmp.t_intrc; tty->termios.c_cc[VQUIT] = tmp.t_quitc; tty->termios.c_cc[VSTART] = tmp.t_startc; tty->termios.c_cc[VSTOP] = tmp.t_stopc; tty->termios.c_cc[VEOF] = tmp.t_eofc; tty->termios.c_cc[VEOL2] = tmp.t_brkc; /* what is brkc anyway? */ - mutex_unlock(&tty->termios_mutex); + up_write(&tty->termios_rwsem); return 0; } #endif @@ -877,7 +688,7 @@ static int get_ltchars(struct tty_struct *tty, struct ltchars __user *ltchars) { struct ltchars tmp; - mutex_lock(&tty->termios_mutex); + down_read(&tty->termios_rwsem); tmp.t_suspc = tty->termios.c_cc[VSUSP]; /* what is dsuspc anyway? */ tmp.t_dsuspc = tty->termios.c_cc[VSUSP]; @@ -886,7 +697,7 @@ static int get_ltchars(struct tty_struct *tty, struct ltchars __user *ltchars) tmp.t_flushc = tty->termios.c_cc[VEOL2]; tmp.t_werasc = tty->termios.c_cc[VWERASE]; tmp.t_lnextc = tty->termios.c_cc[VLNEXT]; - mutex_unlock(&tty->termios_mutex); + up_read(&tty->termios_rwsem); return copy_to_user(ltchars, &tmp, sizeof(tmp)) ? -EFAULT : 0; } @@ -897,7 +708,7 @@ static int set_ltchars(struct tty_struct *tty, struct ltchars __user *ltchars) if (copy_from_user(&tmp, ltchars, sizeof(tmp))) return -EFAULT; - mutex_lock(&tty->termios_mutex); + down_write(&tty->termios_rwsem); tty->termios.c_cc[VSUSP] = tmp.t_suspc; /* what is dsuspc anyway? */ tty->termios.c_cc[VEOL2] = tmp.t_dsuspc; @@ -906,89 +717,58 @@ static int set_ltchars(struct tty_struct *tty, struct ltchars __user *ltchars) tty->termios.c_cc[VEOL2] = tmp.t_flushc; tty->termios.c_cc[VWERASE] = tmp.t_werasc; tty->termios.c_cc[VLNEXT] = tmp.t_lnextc; - mutex_unlock(&tty->termios_mutex); + up_write(&tty->termios_rwsem); return 0; } #endif /** - * send_prio_char - send priority character + * tty_change_softcar - carrier change ioctl helper + * @tty: tty to update + * @enable: enable/disable %CLOCAL * - * Send a high priority character to the tty even if stopped + * Perform a change to the %CLOCAL state and call into the driver layer to make + * it visible. * - * Locking: none for xchar method, write ordering for write method. - */ - -static int send_prio_char(struct tty_struct *tty, char ch) -{ - int was_stopped = tty->stopped; - - if (tty->ops->send_xchar) { - tty->ops->send_xchar(tty, ch); - return 0; - } - - if (tty_write_lock(tty, 0) < 0) - return -ERESTARTSYS; - - if (was_stopped) - start_tty(tty); - tty->ops->write(tty, &ch, 1); - if (was_stopped) - stop_tty(tty); - tty_write_unlock(tty); - return 0; -} - -/** - * tty_change_softcar - carrier change ioctl helper - * @tty: tty to update - * @arg: enable/disable CLOCAL + * Locking: &tty_struct->termios_rwsem. * - * Perform a change to the CLOCAL state and call into the driver - * layer to make it visible. All done with the termios mutex + * Returns: 0 on success, an error otherwise */ - -static int tty_change_softcar(struct tty_struct *tty, int arg) +static int tty_change_softcar(struct tty_struct *tty, bool enable) { int ret = 0; - int bit = arg ? CLOCAL : 0; struct ktermios old; + tcflag_t bit = enable ? CLOCAL : 0; - mutex_lock(&tty->termios_mutex); + down_write(&tty->termios_rwsem); old = tty->termios; tty->termios.c_cflag &= ~CLOCAL; tty->termios.c_cflag |= bit; if (tty->ops->set_termios) tty->ops->set_termios(tty, &old); - if ((tty->termios.c_cflag & CLOCAL) != bit) + if (C_CLOCAL(tty) != bit) ret = -EINVAL; - mutex_unlock(&tty->termios_mutex); + up_write(&tty->termios_rwsem); return ret; } /** - * tty_mode_ioctl - mode related ioctls - * @tty: tty for the ioctl - * @file: file pointer for the tty - * @cmd: command - * @arg: ioctl argument - * - * Perform non line discipline specific mode control ioctls. This - * is designed to be called by line disciplines to ensure they provide - * consistent mode setting. + * tty_mode_ioctl - mode related ioctls + * @tty: tty for the ioctl + * @cmd: command + * @arg: ioctl argument + * + * Perform non-line discipline specific mode control ioctls. This is designed + * to be called by line disciplines to ensure they provide consistent mode + * setting. */ - -int tty_mode_ioctl(struct tty_struct *tty, struct file *file, - unsigned int cmd, unsigned long arg) +int tty_mode_ioctl(struct tty_struct *tty, unsigned int cmd, unsigned long arg) { struct tty_struct *real_tty; void __user *p = (void __user *)arg; int ret = 0; struct ktermios kterm; - BUG_ON(file == NULL); - if (tty->driver->type == TTY_DRIVER_TYPE_PTY && tty->driver->subtype == PTY_TYPE_MASTER) real_tty = tty->link; @@ -1060,15 +840,15 @@ int tty_mode_ioctl(struct tty_struct *tty, struct file *file, ret = -EFAULT; return ret; case TIOCSLCKTRMIOS: - if (!capable(CAP_SYS_ADMIN)) + if (!checkpoint_restore_ns_capable(&init_user_ns)) return -EPERM; copy_termios_locked(real_tty, &kterm); if (user_termios_to_kernel_termios(&kterm, (struct termios __user *) arg)) return -EFAULT; - mutex_lock(&real_tty->termios_mutex); + down_write(&real_tty->termios_rwsem); real_tty->termios_locked = kterm; - mutex_unlock(&real_tty->termios_mutex); + up_write(&real_tty->termios_rwsem); return 0; #else case TIOCGLCKTRMIOS: @@ -1077,36 +857,24 @@ int tty_mode_ioctl(struct tty_struct *tty, struct file *file, ret = -EFAULT; return ret; case TIOCSLCKTRMIOS: - if (!capable(CAP_SYS_ADMIN)) + if (!checkpoint_restore_ns_capable(&init_user_ns)) return -EPERM; copy_termios_locked(real_tty, &kterm); if (user_termios_to_kernel_termios_1(&kterm, (struct termios __user *) arg)) return -EFAULT; - mutex_lock(&real_tty->termios_mutex); + down_write(&real_tty->termios_rwsem); real_tty->termios_locked = kterm; - mutex_unlock(&real_tty->termios_mutex); + up_write(&real_tty->termios_rwsem); return ret; #endif #ifdef TCGETX - case TCGETX: { - struct termiox ktermx; - if (real_tty->termiox == NULL) - return -EINVAL; - mutex_lock(&real_tty->termios_mutex); - memcpy(&ktermx, real_tty->termiox, sizeof(struct termiox)); - mutex_unlock(&real_tty->termios_mutex); - if (copy_to_user(p, &ktermx, sizeof(struct termiox))) - ret = -EFAULT; - return ret; - } + case TCGETX: case TCSETX: - return set_termiox(real_tty, p, 0); case TCSETXW: - return set_termiox(real_tty, p, TERMIOS_WAIT); case TCSETXF: - return set_termiox(real_tty, p, TERMIOS_FLUSH); -#endif + return -ENOTTY; +#endif case TIOCGSOFTCAR: copy_termios(real_tty, &kterm); ret = put_user((kterm.c_cflag & CLOCAL) ? 1 : 0, @@ -1140,7 +908,7 @@ static int __tty_perform_flush(struct tty_struct *tty, unsigned long arg) ld->ops->flush_buffer(tty); tty_unthrottle(tty); } - /* fall through */ + fallthrough; case TCOFLUSH: tty_driver_flush_buffer(tty); break; @@ -1165,8 +933,8 @@ int tty_perform_flush(struct tty_struct *tty, unsigned long arg) } EXPORT_SYMBOL_GPL(tty_perform_flush); -int n_tty_ioctl_helper(struct tty_struct *tty, struct file *file, - unsigned int cmd, unsigned long arg) +int n_tty_ioctl_helper(struct tty_struct *tty, unsigned int cmd, + unsigned long arg) { int retval; @@ -1177,50 +945,41 @@ int n_tty_ioctl_helper(struct tty_struct *tty, struct file *file, return retval; switch (arg) { case TCOOFF: - if (!tty->flow_stopped) { - tty->flow_stopped = 1; - stop_tty(tty); + spin_lock_irq(&tty->flow.lock); + if (!tty->flow.tco_stopped) { + tty->flow.tco_stopped = true; + __stop_tty(tty); } + spin_unlock_irq(&tty->flow.lock); break; case TCOON: - if (tty->flow_stopped) { - tty->flow_stopped = 0; - start_tty(tty); + spin_lock_irq(&tty->flow.lock); + if (tty->flow.tco_stopped) { + tty->flow.tco_stopped = false; + __start_tty(tty); } + spin_unlock_irq(&tty->flow.lock); break; case TCIOFF: if (STOP_CHAR(tty) != __DISABLED_CHAR) - return send_prio_char(tty, STOP_CHAR(tty)); + retval = tty_send_xchar(tty, STOP_CHAR(tty)); break; case TCION: if (START_CHAR(tty) != __DISABLED_CHAR) - return send_prio_char(tty, START_CHAR(tty)); + retval = tty_send_xchar(tty, START_CHAR(tty)); break; default: return -EINVAL; } - return 0; + return retval; case TCFLSH: + retval = tty_check_change(tty); + if (retval) + return retval; return __tty_perform_flush(tty, arg); default: /* Try the mode commands */ - return tty_mode_ioctl(tty, file, cmd, arg); + return tty_mode_ioctl(tty, cmd, arg); } } EXPORT_SYMBOL(n_tty_ioctl_helper); - -#ifdef CONFIG_COMPAT -long n_tty_compat_ioctl_helper(struct tty_struct *tty, struct file *file, - unsigned int cmd, unsigned long arg) -{ - switch (cmd) { - case TIOCGLCKTRMIOS: - case TIOCSLCKTRMIOS: - return tty_mode_ioctl(tty, file, cmd, (unsigned long) compat_ptr(arg)); - default: - return -ENOIOCTLCMD; - } -} -EXPORT_SYMBOL(n_tty_compat_ioctl_helper); -#endif - |