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path: root/drivers/tty/vt/vc_screen.c
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Diffstat (limited to 'drivers/tty/vt/vc_screen.c')
-rw-r--r--drivers/tty/vt/vc_screen.c149
1 files changed, 79 insertions, 70 deletions
diff --git a/drivers/tty/vt/vc_screen.c b/drivers/tty/vt/vc_screen.c
index a672ed192d3..14a2b5f11bc 100644
--- a/drivers/tty/vt/vc_screen.c
+++ b/drivers/tty/vt/vc_screen.c
@@ -1,6 +1,4 @@
/*
- * 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)
@@ -24,17 +22,16 @@
#include <linux/kernel.h>
#include <linux/major.h>
#include <linux/errno.h>
+#include <linux/export.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>
@@ -51,6 +48,8 @@
#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;
@@ -94,7 +93,7 @@ vcs_poll_data_free(struct vcs_poll_data *poll)
static struct vcs_poll_data *
vcs_poll_data_get(struct file *file)
{
- struct vcs_poll_data *poll = file->private_data;
+ struct vcs_poll_data *poll = file->private_data, *kill = NULL;
if (poll)
return poll;
@@ -102,7 +101,7 @@ vcs_poll_data_get(struct file *file)
poll = kzalloc(sizeof(*poll), GFP_KERNEL);
if (!poll)
return NULL;
- poll->cons_num = iminor(file->f_path.dentry->d_inode) & 127;
+ poll->cons_num = iminor(file_inode(file)) & 127;
init_waitqueue_head(&poll->waitq);
poll->notifier.notifier_call = vcs_notifier;
if (register_vt_notifier(&poll->notifier) != 0) {
@@ -123,29 +122,55 @@ vcs_poll_data_get(struct file *file)
file->private_data = poll;
} else {
/* someone else raced ahead of us */
- vcs_poll_data_free(poll);
+ kill = poll;
poll = file->private_data;
}
spin_unlock(&file->f_lock);
+ if (kill)
+ vcs_poll_data_free(kill);
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;
@@ -158,44 +183,32 @@ 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;
+ console_lock();
+ size = vcs_size(file_inode(file));
+ console_unlock();
+ if (size < 0)
+ return size;
+ return fixed_size_llseek(file, offset, orig, size);
}
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;
+ struct inode *inode = file_inode(file);
unsigned int currcons = iminor(inode);
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 +218,10 @@ 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 +242,12 @@ 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)
@@ -355,24 +366,27 @@ 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;
}
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;
+ struct inode *inode = file_inode(file);
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 +396,10 @@ 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 +441,12 @@ 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 +554,7 @@ 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;
}
@@ -586,10 +595,10 @@ vcs_open(struct inode *inode, struct file *filp)
unsigned int currcons = iminor(inode) & 127;
int ret = 0;
- tty_lock();
+ console_lock();
if(currcons && !vc_cons_allocated(currcons-1))
ret = -ENXIO;
- tty_unlock();
+ console_unlock();
return ret;
}
generated by cgit v1.2.3-70-g09d2 (git 2.46.0) at 2025-11-09 20:26:43 +0000