From fc6f6238226e6d1248e1967eae2bf556eaf3ac17 Mon Sep 17 00:00:00 2001 From: Alan Cox Date: Fri, 2 Jan 2009 13:43:17 +0000 Subject: [PATCH] pty: simplify resize We have special case logic for resizing pty/tty pairs. We also have a per driver resize method so for the pty case we should use it. Signed-off-by: Alan Cox Signed-off-by: Linus Torvalds --- drivers/char/hvc_console.c | 2 +- drivers/char/pty.c | 54 +++++++++++++++++++++++++++++++++++++- drivers/char/tty_io.c | 31 ++++++++-------------- drivers/char/vt.c | 14 +++++----- include/linux/tty.h | 3 +-- include/linux/tty_driver.h | 6 ++--- 6 files changed, 74 insertions(+), 36 deletions(-) diff --git a/drivers/char/hvc_console.c b/drivers/char/hvc_console.c index 0587b66d6fc..5a8a4c28c86 100644 --- a/drivers/char/hvc_console.c +++ b/drivers/char/hvc_console.c @@ -529,7 +529,7 @@ static void hvc_set_winsz(struct work_struct *work) tty = tty_kref_get(hp->tty); spin_unlock_irqrestore(&hp->lock, hvc_flags); - tty_do_resize(tty, tty, &ws); + tty_do_resize(tty, &ws); tty_kref_put(tty); } diff --git a/drivers/char/pty.c b/drivers/char/pty.c index 6d4582712b1..b5daaaa9007 100644 --- a/drivers/char/pty.c +++ b/drivers/char/pty.c @@ -230,6 +230,55 @@ static void pty_set_termios(struct tty_struct *tty, tty->termios->c_cflag |= (CS8 | CREAD); } +/** + * pty_do_resize - resize event + * @tty: tty being resized + * @real_tty: real tty (not the same as tty if using a pty/tty pair) + * @rows: rows (character) + * @cols: cols (character) + * + * Update the termios variables and send the neccessary signals to + * peform a terminal resize correctly + */ + +int pty_resize(struct tty_struct *tty, struct winsize *ws) +{ + struct pid *pgrp, *rpgrp; + unsigned long flags; + struct tty_struct *pty = tty->link; + + /* For a PTY we need to lock the tty side */ + mutex_lock(&tty->termios_mutex); + if (!memcmp(ws, &tty->winsize, sizeof(*ws))) + goto done; + + /* Get the PID values and reference them so we can + avoid holding the tty ctrl lock while sending signals. + We need to lock these individually however. */ + + spin_lock_irqsave(&tty->ctrl_lock, flags); + pgrp = get_pid(tty->pgrp); + spin_unlock_irqrestore(&tty->ctrl_lock, flags); + + spin_lock_irqsave(&pty->ctrl_lock, flags); + rpgrp = get_pid(pty->pgrp); + spin_unlock_irqrestore(&pty->ctrl_lock, flags); + + if (pgrp) + kill_pgrp(pgrp, SIGWINCH, 1); + if (rpgrp != pgrp && rpgrp) + kill_pgrp(rpgrp, SIGWINCH, 1); + + put_pid(pgrp); + put_pid(rpgrp); + + tty->winsize = *ws; + pty->winsize = *ws; /* Never used so will go away soon */ +done: + mutex_unlock(&tty->termios_mutex); + return 0; +} + static int pty_install(struct tty_driver *driver, struct tty_struct *tty) { struct tty_struct *o_tty; @@ -290,6 +339,7 @@ static const struct tty_operations pty_ops = { .chars_in_buffer = pty_chars_in_buffer, .unthrottle = pty_unthrottle, .set_termios = pty_set_termios, + .resize = pty_resize }; /* Traditional BSD devices */ @@ -319,6 +369,7 @@ static const struct tty_operations pty_ops_bsd = { .unthrottle = pty_unthrottle, .set_termios = pty_set_termios, .ioctl = pty_bsd_ioctl, + .resize = pty_resize }; static void __init legacy_pty_init(void) @@ -561,7 +612,8 @@ static const struct tty_operations ptm_unix98_ops = { .unthrottle = pty_unthrottle, .set_termios = pty_set_termios, .ioctl = pty_unix98_ioctl, - .shutdown = pty_unix98_shutdown + .shutdown = pty_unix98_shutdown, + .resize = pty_resize }; static const struct tty_operations pty_unix98_ops = { diff --git a/drivers/char/tty_io.c b/drivers/char/tty_io.c index 2a15af65dd1..d33e5ab0617 100644 --- a/drivers/char/tty_io.c +++ b/drivers/char/tty_io.c @@ -2048,7 +2048,6 @@ static int tiocgwinsz(struct tty_struct *tty, struct winsize __user *arg) /** * tty_do_resize - resize event * @tty: tty being resized - * @real_tty: real tty (not the same as tty if using a pty/tty pair) * @rows: rows (character) * @cols: cols (character) * @@ -2056,41 +2055,34 @@ static int tiocgwinsz(struct tty_struct *tty, struct winsize __user *arg) * peform a terminal resize correctly */ -int tty_do_resize(struct tty_struct *tty, struct tty_struct *real_tty, - struct winsize *ws) +int tty_do_resize(struct tty_struct *tty, struct winsize *ws) { - struct pid *pgrp, *rpgrp; + struct pid *pgrp; unsigned long flags; - /* For a PTY we need to lock the tty side */ - mutex_lock(&real_tty->termios_mutex); - if (!memcmp(ws, &real_tty->winsize, sizeof(*ws))) + /* Lock the tty */ + mutex_lock(&tty->termios_mutex); + if (!memcmp(ws, &tty->winsize, sizeof(*ws))) goto done; /* Get the PID values and reference them so we can avoid holding the tty ctrl lock while sending signals */ spin_lock_irqsave(&tty->ctrl_lock, flags); pgrp = get_pid(tty->pgrp); - rpgrp = get_pid(real_tty->pgrp); spin_unlock_irqrestore(&tty->ctrl_lock, flags); if (pgrp) kill_pgrp(pgrp, SIGWINCH, 1); - if (rpgrp != pgrp && rpgrp) - kill_pgrp(rpgrp, SIGWINCH, 1); - put_pid(pgrp); - put_pid(rpgrp); tty->winsize = *ws; - real_tty->winsize = *ws; done: - mutex_unlock(&real_tty->termios_mutex); + mutex_unlock(&tty->termios_mutex); return 0; } /** * tiocswinsz - implement window size set ioctl - * @tty; tty + * @tty; tty side of tty * @arg: user buffer for result * * Copies the user idea of the window size to the kernel. Traditionally @@ -2103,17 +2095,16 @@ done: * then calls into the default method. */ -static int tiocswinsz(struct tty_struct *tty, struct tty_struct *real_tty, - struct winsize __user *arg) +static int tiocswinsz(struct tty_struct *tty, struct winsize __user *arg) { struct winsize tmp_ws; if (copy_from_user(&tmp_ws, arg, sizeof(*arg))) return -EFAULT; if (tty->ops->resize) - return tty->ops->resize(tty, real_tty, &tmp_ws); + return tty->ops->resize(tty, &tmp_ws); else - return tty_do_resize(tty, real_tty, &tmp_ws); + return tty_do_resize(tty, &tmp_ws); } /** @@ -2538,7 +2529,7 @@ long tty_ioctl(struct file *file, unsigned int cmd, unsigned long arg) case TIOCGWINSZ: return tiocgwinsz(real_tty, p); case TIOCSWINSZ: - return tiocswinsz(tty, real_tty, p); + return tiocswinsz(real_tty, p); case TIOCCONS: return real_tty != tty ? -EINVAL : tioccons(file); case FIONBIO: diff --git a/drivers/char/vt.c b/drivers/char/vt.c index 639e126b2bf..80014213fb5 100644 --- a/drivers/char/vt.c +++ b/drivers/char/vt.c @@ -819,8 +819,8 @@ static inline int resize_screen(struct vc_data *vc, int width, int height, * ctrl_lock of the tty IFF a tty is passed. */ -static int vc_do_resize(struct tty_struct *tty, struct tty_struct *real_tty, - struct vc_data *vc, unsigned int cols, unsigned int lines) +static int vc_do_resize(struct tty_struct *tty, struct vc_data *vc, + unsigned int cols, unsigned int lines) { unsigned long old_origin, new_origin, new_scr_end, rlth, rrem, err = 0; unsigned int old_cols, old_rows, old_row_size, old_screen_size; @@ -932,7 +932,7 @@ static int vc_do_resize(struct tty_struct *tty, struct tty_struct *real_tty, ws.ws_row = vc->vc_rows; ws.ws_col = vc->vc_cols; ws.ws_ypixel = vc->vc_scan_lines; - tty_do_resize(tty, real_tty, &ws); + tty_do_resize(tty, &ws); } if (CON_IS_VISIBLE(vc)) @@ -954,13 +954,12 @@ static int vc_do_resize(struct tty_struct *tty, struct tty_struct *real_tty, int vc_resize(struct vc_data *vc, unsigned int cols, unsigned int rows) { - return vc_do_resize(vc->vc_tty, vc->vc_tty, vc, cols, rows); + return vc_do_resize(vc->vc_tty, vc, cols, rows); } /** * vt_resize - resize a VT * @tty: tty to resize - * @real_tty: tty if a pty/tty pair * @ws: winsize attributes * * Resize a virtual terminal. This is called by the tty layer as we @@ -971,14 +970,13 @@ int vc_resize(struct vc_data *vc, unsigned int cols, unsigned int rows) * termios_mutex and the tty ctrl_lock in that order. */ -int vt_resize(struct tty_struct *tty, struct tty_struct *real_tty, - struct winsize *ws) +int vt_resize(struct tty_struct *tty, struct winsize *ws) { struct vc_data *vc = tty->driver_data; int ret; acquire_console_sem(); - ret = vc_do_resize(tty, real_tty, vc, ws->ws_col, ws->ws_row); + ret = vc_do_resize(tty, vc, ws->ws_col, ws->ws_row); release_console_sem(); return ret; } diff --git a/include/linux/tty.h b/include/linux/tty.h index dfc77ded198..f88169787a5 100644 --- a/include/linux/tty.h +++ b/include/linux/tty.h @@ -360,8 +360,7 @@ extern int tty_write_room(struct tty_struct *tty); extern void tty_driver_flush_buffer(struct tty_struct *tty); extern void tty_throttle(struct tty_struct *tty); extern void tty_unthrottle(struct tty_struct *tty); -extern int tty_do_resize(struct tty_struct *tty, struct tty_struct *real_tty, - struct winsize *ws); +extern int tty_do_resize(struct tty_struct *tty, struct winsize *ws); extern void tty_shutdown(struct tty_struct *tty); extern void tty_free_termios(struct tty_struct *tty); extern int is_current_pgrp_orphaned(void); diff --git a/include/linux/tty_driver.h b/include/linux/tty_driver.h index 78416b90158..08e088334db 100644 --- a/include/linux/tty_driver.h +++ b/include/linux/tty_driver.h @@ -196,8 +196,7 @@ * Optional: If not provided then the write method is called under * the atomic write lock to keep it serialized with the ldisc. * - * int (*resize)(struct tty_struct *tty, struct tty_struct *real_tty, - * unsigned int rows, unsigned int cols); + * int (*resize)(struct tty_struct *tty, struct winsize *ws) * * Called when a termios request is issued which changes the * requested terminal geometry. @@ -258,8 +257,7 @@ struct tty_operations { int (*tiocmget)(struct tty_struct *tty, struct file *file); int (*tiocmset)(struct tty_struct *tty, struct file *file, unsigned int set, unsigned int clear); - int (*resize)(struct tty_struct *tty, struct tty_struct *real_tty, - struct winsize *ws); + int (*resize)(struct tty_struct *tty, struct winsize *ws); int (*set_termiox)(struct tty_struct *tty, struct termiox *tnew); #ifdef CONFIG_CONSOLE_POLL int (*poll_init)(struct tty_driver *driver, int line, char *options); -- 2.41.1