diff options
Diffstat (limited to 'drivers/char/vc_screen.c')
| -rw-r--r-- | drivers/char/vc_screen.c | 644 |
1 files changed, 0 insertions, 644 deletions
diff --git a/drivers/char/vc_screen.c b/drivers/char/vc_screen.c deleted file mode 100644 index 273ab44cc91..00000000000 --- a/drivers/char/vc_screen.c +++ /dev/null @@ -1,644 +0,0 @@ -/* - * linux/drivers/char/vc_screen.c - * - * Provide access to virtual console memory. - * /dev/vcs0: the screen as it is being viewed right now (possibly scrolled) - * /dev/vcsN: the screen of /dev/ttyN (1 <= N <= 63) - * [minor: N] - * - * /dev/vcsaN: idem, but including attributes, and prefixed with - * the 4 bytes lines,columns,x,y (as screendump used to give). - * Attribute/character pair is in native endianity. - * [minor: N+128] - * - * This replaces screendump and part of selection, so that the system - * administrator can control access using file system permissions. - * - * aeb@cwi.nl - efter Friedas begravelse - 950211 - * - * machek@k332.feld.cvut.cz - modified not to send characters to wrong console - * - fixed some fatal off-by-one bugs (0-- no longer == -1 -> looping and looping and looping...) - * - making it shorter - scr_readw are macros which expand in PRETTY long code - */ - -#include <linux/kernel.h> -#include <linux/major.h> -#include <linux/errno.h> -#include <linux/tty.h> -#include <linux/interrupt.h> -#include <linux/mm.h> -#include <linux/init.h> -#include <linux/mutex.h> -#include <linux/vt_kern.h> -#include <linux/selection.h> -#include <linux/kbd_kern.h> -#include <linux/console.h> -#include <linux/device.h> -#include <linux/smp_lock.h> -#include <linux/sched.h> -#include <linux/fs.h> -#include <linux/poll.h> -#include <linux/signal.h> -#include <linux/slab.h> -#include <linux/notifier.h> - -#include <asm/uaccess.h> -#include <asm/byteorder.h> -#include <asm/unaligned.h> - -#undef attr -#undef org -#undef addr -#define HEADER_SIZE 4 - -struct vcs_poll_data { - struct notifier_block notifier; - unsigned int cons_num; - bool seen_last_update; - wait_queue_head_t waitq; - struct fasync_struct *fasync; -}; - -static int -vcs_notifier(struct notifier_block *nb, unsigned long code, void *_param) -{ - struct vt_notifier_param *param = _param; - struct vc_data *vc = param->vc; - struct vcs_poll_data *poll = - container_of(nb, struct vcs_poll_data, notifier); - int currcons = poll->cons_num; - - if (code != VT_UPDATE) - return NOTIFY_DONE; - - if (currcons == 0) - currcons = fg_console; - else - currcons--; - if (currcons != vc->vc_num) - return NOTIFY_DONE; - - poll->seen_last_update = false; - wake_up_interruptible(&poll->waitq); - kill_fasync(&poll->fasync, SIGIO, POLL_IN); - return NOTIFY_OK; -} - -static void -vcs_poll_data_free(struct vcs_poll_data *poll) -{ - unregister_vt_notifier(&poll->notifier); - kfree(poll); -} - -static struct vcs_poll_data * -vcs_poll_data_get(struct file *file) -{ - struct vcs_poll_data *poll = file->private_data; - - if (poll) - return poll; - - poll = kzalloc(sizeof(*poll), GFP_KERNEL); - if (!poll) - return NULL; - poll->cons_num = iminor(file->f_path.dentry->d_inode) & 127; - init_waitqueue_head(&poll->waitq); - poll->notifier.notifier_call = vcs_notifier; - if (register_vt_notifier(&poll->notifier) != 0) { - kfree(poll); - return NULL; - } - - /* - * This code may be called either through ->poll() or ->fasync(). - * If we have two threads using the same file descriptor, they could - * both enter this function, both notice that the structure hasn't - * been allocated yet and go ahead allocating it in parallel, but - * only one of them must survive and be shared otherwise we'd leak - * memory with a dangling notifier callback. - */ - spin_lock(&file->f_lock); - if (!file->private_data) { - file->private_data = poll; - } else { - /* someone else raced ahead of us */ - vcs_poll_data_free(poll); - poll = file->private_data; - } - spin_unlock(&file->f_lock); - - return poll; -} - -static int -vcs_size(struct inode *inode) -{ - int size; - int minor = iminor(inode); - int currcons = minor & 127; - struct vc_data *vc; - - if (currcons == 0) - currcons = fg_console; - else - currcons--; - if (!vc_cons_allocated(currcons)) - return -ENXIO; - vc = vc_cons[currcons].d; - - size = vc->vc_rows * vc->vc_cols; - - if (minor & 128) - size = 2*size + HEADER_SIZE; - return size; -} - -static loff_t vcs_lseek(struct file *file, loff_t offset, int orig) -{ - int size; - - mutex_lock(&con_buf_mtx); - size = vcs_size(file->f_path.dentry->d_inode); - switch (orig) { - default: - mutex_unlock(&con_buf_mtx); - return -EINVAL; - case 2: - offset += size; - break; - case 1: - offset += file->f_pos; - case 0: - break; - } - if (offset < 0 || offset > size) { - mutex_unlock(&con_buf_mtx); - return -EINVAL; - } - file->f_pos = offset; - mutex_unlock(&con_buf_mtx); - return file->f_pos; -} - - -static ssize_t -vcs_read(struct file *file, char __user *buf, size_t count, loff_t *ppos) -{ - struct inode *inode = file->f_path.dentry->d_inode; - unsigned int currcons = iminor(inode); - struct vc_data *vc; - struct vcs_poll_data *poll; - long pos; - long viewed, attr, read; - int col, maxcol; - unsigned short *org = NULL; - ssize_t ret; - - mutex_lock(&con_buf_mtx); - - pos = *ppos; - - /* Select the proper current console and verify - * sanity of the situation under the console lock. - */ - acquire_console_sem(); - - attr = (currcons & 128); - currcons = (currcons & 127); - if (currcons == 0) { - currcons = fg_console; - viewed = 1; - } else { - currcons--; - viewed = 0; - } - ret = -ENXIO; - if (!vc_cons_allocated(currcons)) - goto unlock_out; - vc = vc_cons[currcons].d; - - ret = -EINVAL; - if (pos < 0) - goto unlock_out; - poll = file->private_data; - if (count && poll) - poll->seen_last_update = true; - read = 0; - ret = 0; - while (count) { - char *con_buf0, *con_buf_start; - long this_round, size; - ssize_t orig_count; - long p = pos; - - /* Check whether we are above size each round, - * as copy_to_user at the end of this loop - * could sleep. - */ - size = vcs_size(inode); - if (pos >= size) - break; - if (count > size - pos) - count = size - pos; - - this_round = count; - if (this_round > CON_BUF_SIZE) - this_round = CON_BUF_SIZE; - - /* Perform the whole read into the local con_buf. - * Then we can drop the console spinlock and safely - * attempt to move it to userspace. - */ - - con_buf_start = con_buf0 = con_buf; - orig_count = this_round; - maxcol = vc->vc_cols; - if (!attr) { - org = screen_pos(vc, p, viewed); - col = p % maxcol; - p += maxcol - col; - while (this_round-- > 0) { - *con_buf0++ = (vcs_scr_readw(vc, org++) & 0xff); - if (++col == maxcol) { - org = screen_pos(vc, p, viewed); - col = 0; - p += maxcol; - } - } - } else { - if (p < HEADER_SIZE) { - size_t tmp_count; - - con_buf0[0] = (char)vc->vc_rows; - con_buf0[1] = (char)vc->vc_cols; - getconsxy(vc, con_buf0 + 2); - - con_buf_start += p; - this_round += p; - if (this_round > CON_BUF_SIZE) { - this_round = CON_BUF_SIZE; - orig_count = this_round - p; - } - - tmp_count = HEADER_SIZE; - if (tmp_count > this_round) - tmp_count = this_round; - - /* Advance state pointers and move on. */ - this_round -= tmp_count; - p = HEADER_SIZE; - con_buf0 = con_buf + HEADER_SIZE; - /* If this_round >= 0, then p is even... */ - } else if (p & 1) { - /* Skip first byte for output if start address is odd - * Update region sizes up/down depending on free - * space in buffer. - */ - con_buf_start++; - if (this_round < CON_BUF_SIZE) - this_round++; - else - orig_count--; - } - if (this_round > 0) { - unsigned short *tmp_buf = (unsigned short *)con_buf0; - - p -= HEADER_SIZE; - p /= 2; - col = p % maxcol; - - org = screen_pos(vc, p, viewed); - p += maxcol - col; - - /* Buffer has even length, so we can always copy - * character + attribute. We do not copy last byte - * to userspace if this_round is odd. - */ - this_round = (this_round + 1) >> 1; - - while (this_round) { - *tmp_buf++ = vcs_scr_readw(vc, org++); - this_round --; - if (++col == maxcol) { - org = screen_pos(vc, p, viewed); - col = 0; - p += maxcol; - } - } - } - } - - /* Finally, release the console semaphore while we push - * all the data to userspace from our temporary buffer. - * - * AKPM: Even though it's a semaphore, we should drop it because - * the pagefault handling code may want to call printk(). - */ - - release_console_sem(); - ret = copy_to_user(buf, con_buf_start, orig_count); - acquire_console_sem(); - - if (ret) { - read += (orig_count - ret); - ret = -EFAULT; - break; - } - buf += orig_count; - pos += orig_count; - read += orig_count; - count -= orig_count; - } - *ppos += read; - if (read) - ret = read; -unlock_out: - release_console_sem(); - mutex_unlock(&con_buf_mtx); - return ret; -} - -static ssize_t -vcs_write(struct file *file, const char __user *buf, size_t count, loff_t *ppos) -{ - struct inode *inode = file->f_path.dentry->d_inode; - unsigned int currcons = iminor(inode); - struct vc_data *vc; - long pos; - long viewed, attr, size, written; - char *con_buf0; - int col, maxcol; - u16 *org0 = NULL, *org = NULL; - size_t ret; - - mutex_lock(&con_buf_mtx); - - pos = *ppos; - - /* Select the proper current console and verify - * sanity of the situation under the console lock. - */ - acquire_console_sem(); - - attr = (currcons & 128); - currcons = (currcons & 127); - - if (currcons == 0) { - currcons = fg_console; - viewed = 1; - } else { - currcons--; - viewed = 0; - } - ret = -ENXIO; - if (!vc_cons_allocated(currcons)) - goto unlock_out; - vc = vc_cons[currcons].d; - - size = vcs_size(inode); - ret = -EINVAL; - if (pos < 0 || pos > size) - goto unlock_out; - if (count > size - pos) - count = size - pos; - written = 0; - while (count) { - long this_round = count; - size_t orig_count; - long p; - - if (this_round > CON_BUF_SIZE) - this_round = CON_BUF_SIZE; - - /* Temporarily drop the console lock so that we can read - * in the write data from userspace safely. - */ - release_console_sem(); - ret = copy_from_user(con_buf, buf, this_round); - acquire_console_sem(); - - if (ret) { - this_round -= ret; - if (!this_round) { - /* Abort loop if no data were copied. Otherwise - * fail with -EFAULT. - */ - if (written) - break; - ret = -EFAULT; - goto unlock_out; - } - } - - /* The vcs_size might have changed while we slept to grab - * the user buffer, so recheck. - * Return data written up to now on failure. - */ - size = vcs_size(inode); - if (pos >= size) - break; - if (this_round > size - pos) - this_round = size - pos; - - /* OK, now actually push the write to the console - * under the lock using the local kernel buffer. - */ - - con_buf0 = con_buf; - orig_count = this_round; - maxcol = vc->vc_cols; - p = pos; - if (!attr) { - org0 = org = screen_pos(vc, p, viewed); - col = p % maxcol; - p += maxcol - col; - - while (this_round > 0) { - unsigned char c = *con_buf0++; - - this_round--; - vcs_scr_writew(vc, - (vcs_scr_readw(vc, org) & 0xff00) | c, org); - org++; - if (++col == maxcol) { - org = screen_pos(vc, p, viewed); - col = 0; - p += maxcol; - } - } - } else { - if (p < HEADER_SIZE) { - char header[HEADER_SIZE]; - - getconsxy(vc, header + 2); - while (p < HEADER_SIZE && this_round > 0) { - this_round--; - header[p++] = *con_buf0++; - } - if (!viewed) - putconsxy(vc, header + 2); - } - p -= HEADER_SIZE; - col = (p/2) % maxcol; - if (this_round > 0) { - org0 = org = screen_pos(vc, p/2, viewed); - if ((p & 1) && this_round > 0) { - char c; - - this_round--; - c = *con_buf0++; -#ifdef __BIG_ENDIAN - vcs_scr_writew(vc, c | - (vcs_scr_readw(vc, org) & 0xff00), org); -#else - vcs_scr_writew(vc, (c << 8) | - (vcs_scr_readw(vc, org) & 0xff), org); -#endif - org++; - p++; - if (++col == maxcol) { - org = screen_pos(vc, p/2, viewed); - col = 0; - } - } - p /= 2; - p += maxcol - col; - } - while (this_round > 1) { - unsigned short w; - - w = get_unaligned(((unsigned short *)con_buf0)); - vcs_scr_writew(vc, w, org++); - con_buf0 += 2; - this_round -= 2; - if (++col == maxcol) { - org = screen_pos(vc, p, viewed); - col = 0; - p += maxcol; - } - } - if (this_round > 0) { - unsigned char c; - - c = *con_buf0++; -#ifdef __BIG_ENDIAN - vcs_scr_writew(vc, (vcs_scr_readw(vc, org) & 0xff) | (c << 8), org); -#else - vcs_scr_writew(vc, (vcs_scr_readw(vc, org) & 0xff00) | c, org); -#endif - } - } - count -= orig_count; - written += orig_count; - buf += orig_count; - pos += orig_count; - if (org0) - update_region(vc, (unsigned long)(org0), org - org0); - } - *ppos += written; - ret = written; - if (written) - vcs_scr_updated(vc); - -unlock_out: - release_console_sem(); - - mutex_unlock(&con_buf_mtx); - - return ret; -} - -static unsigned int -vcs_poll(struct file *file, poll_table *wait) -{ - struct vcs_poll_data *poll = vcs_poll_data_get(file); - int ret = 0; - - if (poll) { - poll_wait(file, &poll->waitq, wait); - if (!poll->seen_last_update) - ret = POLLIN | POLLRDNORM; - } - return ret; -} - -static int -vcs_fasync(int fd, struct file *file, int on) -{ - struct vcs_poll_data *poll = file->private_data; - - if (!poll) { - /* don't allocate anything if all we want is disable fasync */ - if (!on) - return 0; - poll = vcs_poll_data_get(file); - if (!poll) - return -ENOMEM; - } - - return fasync_helper(fd, file, on, &poll->fasync); -} - -static int -vcs_open(struct inode *inode, struct file *filp) -{ - unsigned int currcons = iminor(inode) & 127; - int ret = 0; - - tty_lock(); - if(currcons && !vc_cons_allocated(currcons-1)) - ret = -ENXIO; - tty_unlock(); - return ret; -} - -static int vcs_release(struct inode *inode, struct file *file) -{ - struct vcs_poll_data *poll = file->private_data; - - if (poll) - vcs_poll_data_free(poll); - return 0; -} - -static const struct file_operations vcs_fops = { - .llseek = vcs_lseek, - .read = vcs_read, - .write = vcs_write, - .poll = vcs_poll, - .fasync = vcs_fasync, - .open = vcs_open, - .release = vcs_release, -}; - -static struct class *vc_class; - -void vcs_make_sysfs(int index) -{ - device_create(vc_class, NULL, MKDEV(VCS_MAJOR, index + 1), NULL, - "vcs%u", index + 1); - device_create(vc_class, NULL, MKDEV(VCS_MAJOR, index + 129), NULL, - "vcsa%u", index + 1); -} - -void vcs_remove_sysfs(int index) -{ - device_destroy(vc_class, MKDEV(VCS_MAJOR, index + 1)); - device_destroy(vc_class, MKDEV(VCS_MAJOR, index + 129)); -} - -int __init vcs_init(void) -{ - unsigned int i; - - if (register_chrdev(VCS_MAJOR, "vcs", &vcs_fops)) - panic("unable to get major %d for vcs device", VCS_MAJOR); - vc_class = class_create(THIS_MODULE, "vc"); - - device_create(vc_class, NULL, MKDEV(VCS_MAJOR, 0), NULL, "vcs"); - device_create(vc_class, NULL, MKDEV(VCS_MAJOR, 128), NULL, "vcsa"); - for (i = 0; i < MIN_NR_CONSOLES; i++) - vcs_make_sysfs(i); - return 0; -} |