diff options
| -rw-r--r-- | drivers/tty/vt/vc_screen.c | 98 | ||||
| -rw-r--r-- | drivers/tty/vt/vt.c | 12 | ||||
| -rw-r--r-- | include/linux/vt_kern.h | 8 |
3 files changed, 52 insertions, 66 deletions
diff --git a/drivers/tty/vt/vc_screen.c b/drivers/tty/vt/vc_screen.c index 3c27c4b..7b3bfbe 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; @@ -158,17 +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) { - mutex_unlock(&con_buf_mtx); + if (size < 0) return size; - } switch (orig) { default: - mutex_unlock(&con_buf_mtx); return -EINVAL; case 2: offset += size; @@ -179,11 +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; } @@ -196,12 +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; @@ -211,18 +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) @@ -367,7 +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; } @@ -378,13 +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; @@ -394,19 +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; @@ -561,9 +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; } diff --git a/drivers/tty/vt/vt.c b/drivers/tty/vt/vt.c index d5669ff..798df6f 100644 --- a/drivers/tty/vt/vt.c +++ b/drivers/tty/vt/vt.c @@ -2068,18 +2068,6 @@ static void do_con_trol(struct tty_struct *tty, struct vc_data *vc, int c) } } -/* This is a temporary buffer used to prepare a tty console write - * so that we can easily avoid touching user space while holding the - * console spinlock. It is allocated in con_init and is shared by - * this code and the vc_screen read/write tty calls. - * - * We have to allocate this statically in the kernel data section - * since console_init (and thus con_init) are called before any - * kernel memory allocation is available. - */ -char con_buf[CON_BUF_SIZE]; -DEFINE_MUTEX(con_buf_mtx); - /* is_double_width() is based on the wcwidth() implementation by * Markus Kuhn -- 2007-05-26 (Unicode 5.0) * Latest version: http://www.cl.cam.ac.uk/~mgk25/ucs/wcwidth.c diff --git a/include/linux/vt_kern.h b/include/linux/vt_kern.h index 6625cc1..4d05e14 100644 --- a/include/linux/vt_kern.h +++ b/include/linux/vt_kern.h @@ -142,14 +142,6 @@ static inline bool vt_force_oops_output(struct vc_data *vc) return false; } -/* - * vc_screen.c shares this temporary buffer with the console write code so that - * we can easily avoid touching user space while holding the console spinlock. - */ - -#define CON_BUF_SIZE (CONFIG_BASE_SMALL ? 256 : PAGE_SIZE) -extern char con_buf[CON_BUF_SIZE]; -extern struct mutex con_buf_mtx; extern char vt_dont_switch; extern int default_utf8; extern int global_cursor_default; |