drivers/char/tty_io.c: Avoid panic when no console is configured.
[safe/jmp/linux-2.6] / drivers / char / vt.c
index 935f1c2..a5af607 100644 (file)
@@ -59,7 +59,7 @@
  * by Martin Mares <mj@atrey.karlin.mff.cuni.cz>, July 1998
  *
  * Removed old-style timers, introduced console_timer, made timer
- * deletion SMP-safe.  17Jun00, Andrew Morton <andrewm@uow.edu.au>
+ * deletion SMP-safe.  17Jun00, Andrew Morton
  *
  * Removed console_lock, enabled interrupts across all console operations
  * 13 March 2001, Andrew Morton
 #include <linux/font.h>
 #include <linux/bitops.h>
 #include <linux/notifier.h>
-
-#include <asm/io.h>
+#include <linux/device.h>
+#include <linux/io.h>
 #include <asm/system.h>
-#include <asm/uaccess.h>
+#include <linux/uaccess.h>
 
 #define MAX_NR_CON_DRIVER 16
 
@@ -261,7 +261,7 @@ static void notify_update(struct vc_data *vc)
 #ifdef VT_BUF_VRAM_ONLY
 #define DO_UPDATE(vc)  0
 #else
-#define DO_UPDATE(vc)  CON_IS_VISIBLE(vc)
+#define DO_UPDATE(vc)  (CON_IS_VISIBLE(vc) && !console_blanked)
 #endif
 
 static inline unsigned short *screenpos(struct vc_data *vc, int offset, int viewed)
@@ -301,7 +301,7 @@ static void scrup(struct vc_data *vc, unsigned int t, unsigned int b, int nr)
        d = (unsigned short *)(vc->vc_origin + vc->vc_size_row * t);
        s = (unsigned short *)(vc->vc_origin + vc->vc_size_row * (t + nr));
        scr_memmovew(d, s, (b - t - nr) * vc->vc_size_row);
-       scr_memsetw(d + (b - t - nr) * vc->vc_cols, vc->vc_scrl_erase_char,
+       scr_memsetw(d + (b - t - nr) * vc->vc_cols, vc->vc_video_erase_char,
                    vc->vc_size_row * nr);
 }
 
@@ -319,7 +319,7 @@ static void scrdown(struct vc_data *vc, unsigned int t, unsigned int b, int nr)
        s = (unsigned short *)(vc->vc_origin + vc->vc_size_row * t);
        step = vc->vc_cols * nr;
        scr_memmovew(s + step, s, (b - t - nr) * vc->vc_size_row);
-       scr_memsetw(s, vc->vc_scrl_erase_char, 2 * step);
+       scr_memsetw(s, vc->vc_video_erase_char, 2 * step);
 }
 
 static void do_update_region(struct vc_data *vc, unsigned long start, int count)
@@ -434,7 +434,6 @@ static void update_attr(struct vc_data *vc)
                      vc->vc_blink, vc->vc_underline,
                      vc->vc_reverse ^ vc->vc_decscnm, vc->vc_italic);
        vc->vc_video_erase_char = (build_attr(vc, vc->vc_color, 1, vc->vc_blink, 0, vc->vc_decscnm, 0) << 8) | ' ';
-       vc->vc_scrl_erase_char = (build_attr(vc, vc->vc_def_color, 1, false, false, vc->vc_decscnm, false) << 8) | ' ';
 }
 
 /* Note: inverting the screen twice should revert to the original state */
@@ -803,7 +802,25 @@ static inline int resize_screen(struct vc_data *vc, int width, int height,
  */
 #define VC_RESIZE_MAXCOL (32767)
 #define VC_RESIZE_MAXROW (32767)
-int vc_resize(struct vc_data *vc, unsigned int cols, unsigned int lines)
+
+/**
+ *     vc_do_resize    -       resizing method for the tty
+ *     @tty: tty being resized
+ *     @real_tty: real tty (different to tty if a pty/tty pair)
+ *     @vc: virtual console private data
+ *     @cols: columns
+ *     @lines: lines
+ *
+ *     Resize a virtual console, clipping according to the actual constraints.
+ *     If the caller passes a tty structure then update the termios winsize
+ *     information and perform any neccessary signal handling.
+ *
+ *     Caller must hold the console semaphore. Takes the termios mutex and
+ *     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)
 {
        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;
@@ -907,26 +924,15 @@ int vc_resize(struct vc_data *vc, unsigned int cols, unsigned int lines)
        gotoxy(vc, vc->vc_x, vc->vc_y);
        save_cur(vc);
 
-       if (vc->vc_tty) {
-               struct winsize ws, *cws = &vc->vc_tty->winsize;
-               struct pid *pgrp = NULL;
-
+       if (tty) {
+               /* Rewrite the requested winsize data with the actual
+                  resulting sizes */
+               struct winsize ws;
                memset(&ws, 0, sizeof(ws));
                ws.ws_row = vc->vc_rows;
                ws.ws_col = vc->vc_cols;
                ws.ws_ypixel = vc->vc_scan_lines;
-
-               mutex_lock(&vc->vc_tty->termios_mutex);
-               spin_lock_irq(&vc->vc_tty->ctrl_lock);
-               if ((ws.ws_row != cws->ws_row || ws.ws_col != cws->ws_col))
-                       pgrp = get_pid(vc->vc_tty->pgrp);
-               spin_unlock_irq(&vc->vc_tty->ctrl_lock);
-               if (pgrp) {
-                       kill_pgrp(vc->vc_tty->pgrp, SIGWINCH, 1);
-                       put_pid(pgrp);
-               }
-               *cws = ws;
-               mutex_unlock(&vc->vc_tty->termios_mutex);
+               tty_do_resize(tty, real_tty, &ws);
        }
 
        if (CON_IS_VISIBLE(vc))
@@ -934,14 +940,47 @@ int vc_resize(struct vc_data *vc, unsigned int cols, unsigned int lines)
        return err;
 }
 
-int vc_lock_resize(struct vc_data *vc, unsigned int cols, unsigned int lines)
+/**
+ *     vc_resize               -       resize a VT
+ *     @vc: virtual console
+ *     @cols: columns
+ *     @rows: rows
+ *
+ *     Resize a virtual console as seen from the console end of things. We
+ *     use the common vc_do_resize methods to update the structures. The
+ *     caller must hold the console sem to protect console internals and
+ *     vc->vc_tty
+ */
+
+int vc_resize(struct vc_data *vc, unsigned int cols, unsigned int rows)
 {
-       int rc;
+       return vc_do_resize(vc->vc_tty, 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
+ *     register our own handler for resizing. The mutual helper does all
+ *     the actual work.
+ *
+ *     Takes the console sem and the called methods then take the tty
+ *     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)
+{
+       struct vc_data *vc = tty->driver_data;
+       int ret;
 
        acquire_console_sem();
-       rc = vc_resize(vc, cols, lines);
+       ret = vc_do_resize(tty, real_tty, vc, ws->ws_col, ws->ws_row);
        release_console_sem();
-       return rc;
+       return ret;
 }
 
 void vc_deallocate(unsigned int currcons)
@@ -1605,7 +1644,10 @@ static void reset_terminal(struct vc_data *vc, int do_clear)
        vc->vc_tab_stop[1]      =
        vc->vc_tab_stop[2]      =
        vc->vc_tab_stop[3]      =
-       vc->vc_tab_stop[4]      = 0x01010101;
+       vc->vc_tab_stop[4]      =
+       vc->vc_tab_stop[5]      =
+       vc->vc_tab_stop[6]      =
+       vc->vc_tab_stop[7]      = 0x01010101;
 
        vc->vc_bell_pitch = DEFAULT_BELL_PITCH;
        vc->vc_bell_duration = DEFAULT_BELL_DURATION;
@@ -1896,7 +1938,10 @@ static void do_con_trol(struct tty_struct *tty, struct vc_data *vc, int c)
                                        vc->vc_tab_stop[1] =
                                        vc->vc_tab_stop[2] =
                                        vc->vc_tab_stop[3] =
-                                       vc->vc_tab_stop[4] = 0;
+                                       vc->vc_tab_stop[4] =
+                                       vc->vc_tab_stop[5] =
+                                       vc->vc_tab_stop[6] =
+                                       vc->vc_tab_stop[7] = 0;
                        }
                        return;
                case 'm':
@@ -2096,27 +2141,9 @@ static int do_con_write(struct tty_struct *tty, const unsigned char *buf, int co
            release_console_sem();
            return 0;
        }
-       release_console_sem();
-
        orig_buf = buf;
        orig_count = count;
 
-       /* At this point 'buf' is guaranteed to be a kernel buffer
-        * and therefore no access to userspace (and therefore sleeping)
-        * will be needed.  The con_buf_mtx serializes all tty based
-        * console rendering and vcs write/read operations.  We hold
-        * the console spinlock during the entire write.
-        */
-
-       acquire_console_sem();
-
-       vc = tty->driver_data;
-       if (vc == NULL) {
-               printk(KERN_ERR "vt: argh, driver_data _became_ NULL !\n");
-               release_console_sem();
-               goto out;
-       }
-
        himask = vc->vc_hi_font_mask;
        charmask = himask ? 0x1ff : 0xff;
 
@@ -2211,7 +2238,7 @@ rescan_last_byte:
                        c = 0xfffd;
                    tc = c;
                } else {        /* no utf or alternate charset mode */
-                   tc = vc->vc_translate[vc->vc_toggle_meta ? (c | 0x80) : c];
+                   tc = vc_translate(vc, c);
                }
 
                param.c = tc;
@@ -2330,8 +2357,6 @@ rescan_last_byte:
        FLUSH
        console_conditional_schedule();
        release_console_sem();
-
-out:
        notify_update(vc);
        return n;
 #undef FLUSH
@@ -2543,8 +2568,6 @@ int tioclinux(struct tty_struct *tty, unsigned long arg)
        int lines;
        int ret;
 
-       if (tty->driver->type != TTY_DRIVER_TYPE_CONSOLE)
-               return -EINVAL;
        if (current->signal->tty != tty && !capable(CAP_SYS_ADMIN))
                return -EPERM;
        if (get_user(type, p))
@@ -2738,6 +2761,12 @@ static int con_open(struct tty_struct *tty, struct file *filp)
                ret = vc_allocate(currcons);
                if (ret == 0) {
                        struct vc_data *vc = vc_cons[currcons].d;
+
+                       /* Still being freed */
+                       if (vc->vc_tty) {
+                               release_console_sem();
+                               return -ERESTARTSYS;
+                       }
                        tty->driver_data = vc;
                        vc->vc_tty = tty;
 
@@ -2749,8 +2778,8 @@ static int con_open(struct tty_struct *tty, struct file *filp)
                                tty->termios->c_iflag |= IUTF8;
                        else
                                tty->termios->c_iflag &= ~IUTF8;
-                       release_console_sem();
                        vcs_make_sysfs(tty);
+                       release_console_sem();
                        return ret;
                }
        }
@@ -2758,34 +2787,20 @@ static int con_open(struct tty_struct *tty, struct file *filp)
        return ret;
 }
 
-/*
- * We take tty_mutex in here to prevent another thread from coming in via init_dev
- * and taking a ref against the tty while we're in the process of forgetting
- * about it and cleaning things up.
- *
- * This is because vcs_remove_sysfs() can sleep and will drop the BKL.
- */
 static void con_close(struct tty_struct *tty, struct file *filp)
 {
-       mutex_lock(&tty_mutex);
-       acquire_console_sem();
-       if (tty && tty->count == 1) {
-               struct vc_data *vc = tty->driver_data;
+       /* Nothing to do - we defer to shutdown */
+}
 
-               if (vc)
-                       vc->vc_tty = NULL;
-               tty->driver_data = NULL;
-               release_console_sem();
-               vcs_remove_sysfs(tty);
-               mutex_unlock(&tty_mutex);
-               /*
-                * tty_mutex is released, but we still hold BKL, so there is
-                * still exclusion against init_dev()
-                */
-               return;
-       }
+static void con_shutdown(struct tty_struct *tty)
+{
+       struct vc_data *vc = tty->driver_data;
+       BUG_ON(vc == NULL);
+       acquire_console_sem();
+       vc->vc_tty = NULL;
+       vcs_remove_sysfs(tty);
        release_console_sem();
-       mutex_unlock(&tty_mutex);
+       tty_shutdown(tty);
 }
 
 static int default_italic_color    = 2; // green (ASCII)
@@ -2909,10 +2924,20 @@ static const struct tty_operations con_ops = {
        .start = con_start,
        .throttle = con_throttle,
        .unthrottle = con_unthrottle,
+       .resize = vt_resize,
+       .shutdown = con_shutdown
 };
 
-int __init vty_init(void)
+static struct cdev vc0_cdev;
+
+int __init vty_init(const struct file_operations *console_fops)
 {
+       cdev_init(&vc0_cdev, console_fops);
+       if (cdev_add(&vc0_cdev, MKDEV(TTY_MAJOR, 0), 1) ||
+           register_chrdev_region(MKDEV(TTY_MAJOR, 0), 1, "/dev/vc/0") < 0)
+               panic("Couldn't register /dev/tty0 driver\n");
+       device_create(tty_class, NULL, MKDEV(TTY_MAJOR, 0), NULL, "tty0");
+
        vcs_init();
 
        console_driver = alloc_tty_driver(MAX_NR_CONSOLES);
@@ -2931,7 +2956,6 @@ int __init vty_init(void)
        tty_set_operations(console_driver, &con_ops);
        if (tty_register_driver(console_driver))
                panic("Couldn't register console driver\n");
-
        kbd_init();
        console_map_init();
 #ifdef CONFIG_PROM_CONSOLE
@@ -3426,8 +3450,9 @@ int register_con_driver(const struct consw *csw, int first, int last)
                goto err;
 
        con_driver->dev = device_create(vtconsole_class, NULL,
-                                       MKDEV(0, con_driver->node),
-                                       "vtcon%i", con_driver->node);
+                                               MKDEV(0, con_driver->node),
+                                               NULL, "vtcon%i",
+                                               con_driver->node);
 
        if (IS_ERR(con_driver->dev)) {
                printk(KERN_WARNING "Unable to create device for %s; "
@@ -3536,8 +3561,9 @@ static int __init vtconsole_class_init(void)
 
                if (con->con && !con->dev) {
                        con->dev = device_create(vtconsole_class, NULL,
-                                                MKDEV(0, con->node),
-                                                "vtcon%i", con->node);
+                                                        MKDEV(0, con->node),
+                                                        NULL, "vtcon%i",
+                                                        con->node);
 
                        if (IS_ERR(con->dev)) {
                                printk(KERN_WARNING "Unable to create "
@@ -4061,7 +4087,6 @@ EXPORT_SYMBOL(default_blu);
 EXPORT_SYMBOL(update_region);
 EXPORT_SYMBOL(redraw_screen);
 EXPORT_SYMBOL(vc_resize);
-EXPORT_SYMBOL(vc_lock_resize);
 EXPORT_SYMBOL(fg_console);
 EXPORT_SYMBOL(console_blank_hook);
 EXPORT_SYMBOL(console_blanked);