diff options
Diffstat (limited to 'drivers/tty/vt/vc_screen.c')
| -rw-r--r-- | drivers/tty/vt/vc_screen.c | 110 |
1 files changed, 67 insertions, 43 deletions
diff --git a/drivers/tty/vt/vc_screen.c b/drivers/tty/vt/vc_screen.c index a672ed192d33..7b3bfbe2e6de 100644 --- a/drivers/tty/vt/vc_screen.c +++ b/drivers/tty/vt/vc_screen.c @@ -28,7 +28,6 @@ #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> @@ -51,6 +50,8 @@ #undef addr #define HEADER_SIZE 4 +#define CON_BUF_SIZE (CONFIG_BASE_SMALL ? 256 : PAGE_SIZE) + struct vcs_poll_data { struct notifier_block notifier; unsigned int cons_num; @@ -131,21 +132,45 @@ vcs_poll_data_get(struct file *file) return poll; } +/* + * Returns VC for inode. + * Must be called with console_lock. + */ +static struct vc_data* +vcs_vc(struct inode *inode, int *viewed) +{ + unsigned int currcons = iminor(inode) & 127; + + WARN_CONSOLE_UNLOCKED(); + + if (currcons == 0) { + currcons = fg_console; + if (viewed) + *viewed = 1; + } else { + currcons--; + if (viewed) + *viewed = 0; + } + return vc_cons[currcons].d; +} + +/* + * Returns size for VC carried by inode. + * Must be called with console_lock. + */ 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)) + WARN_CONSOLE_UNLOCKED(); + + vc = vcs_vc(inode, NULL); + if (!vc) return -ENXIO; - vc = vc_cons[currcons].d; size = vc->vc_rows * vc->vc_cols; @@ -158,11 +183,13 @@ static loff_t vcs_lseek(struct file *file, loff_t offset, int orig) { int size; - mutex_lock(&con_buf_mtx); + console_lock(); size = vcs_size(file->f_path.dentry->d_inode); + console_unlock(); + if (size < 0) + return size; switch (orig) { default: - mutex_unlock(&con_buf_mtx); return -EINVAL; case 2: offset += size; @@ -173,11 +200,9 @@ static loff_t vcs_lseek(struct file *file, loff_t offset, int orig) 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; } @@ -190,12 +215,15 @@ vcs_read(struct file *file, char __user *buf, size_t count, loff_t *ppos) struct vc_data *vc; struct vcs_poll_data *poll; long pos; - long viewed, attr, read; - int col, maxcol; + long attr, read; + int col, maxcol, viewed; unsigned short *org = NULL; ssize_t ret; + char *con_buf; - mutex_lock(&con_buf_mtx); + con_buf = (char *) __get_free_page(GFP_KERNEL); + if (!con_buf) + return -ENOMEM; pos = *ppos; @@ -205,18 +233,10 @@ vcs_read(struct file *file, char __user *buf, size_t count, loff_t *ppos) console_lock(); 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)) + vc = vcs_vc(inode, &viewed); + if (!vc) goto unlock_out; - vc = vc_cons[currcons].d; ret = -EINVAL; if (pos < 0) @@ -237,6 +257,12 @@ vcs_read(struct file *file, char __user *buf, size_t count, loff_t *ppos) * could sleep. */ size = vcs_size(inode); + if (size < 0) { + if (read) + break; + ret = size; + goto unlock_out; + } if (pos >= size) break; if (count > size - pos) @@ -355,7 +381,7 @@ vcs_read(struct file *file, char __user *buf, size_t count, loff_t *ppos) ret = read; unlock_out: console_unlock(); - mutex_unlock(&con_buf_mtx); + free_page((unsigned long) con_buf); return ret; } @@ -366,13 +392,16 @@ vcs_write(struct file *file, const char __user *buf, size_t count, loff_t *ppos) unsigned int currcons = iminor(inode); struct vc_data *vc; long pos; - long viewed, attr, size, written; + long attr, size, written; char *con_buf0; - int col, maxcol; + int col, maxcol, viewed; u16 *org0 = NULL, *org = NULL; size_t ret; + char *con_buf; - mutex_lock(&con_buf_mtx); + con_buf = (char *) __get_free_page(GFP_KERNEL); + if (!con_buf) + return -ENOMEM; pos = *ppos; @@ -382,19 +411,10 @@ vcs_write(struct file *file, const char __user *buf, size_t count, loff_t *ppos) console_lock(); 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)) + vc = vcs_vc(inode, &viewed); + if (!vc) goto unlock_out; - vc = vc_cons[currcons].d; size = vcs_size(inode); ret = -EINVAL; @@ -436,6 +456,12 @@ vcs_write(struct file *file, const char __user *buf, size_t count, loff_t *ppos) * Return data written up to now on failure. */ size = vcs_size(inode); + if (size < 0) { + if (written) + break; + ret = size; + goto unlock_out; + } if (pos >= size) break; if (this_round > size - pos) @@ -543,9 +569,7 @@ vcs_write(struct file *file, const char __user *buf, size_t count, loff_t *ppos) unlock_out: console_unlock(); - - mutex_unlock(&con_buf_mtx); - + free_page((unsigned long) con_buf); return ret; } |