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;
long pos;
long viewed, attr, read;
int col, maxcol;
unsigned short *org = NULL;
ssize_t ret;
mutex_lock(&con_buf_mtx);
pos = *ppos;
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;
read = 0;
ret = 0;
while (count) {
char *con_buf0, *con_buf_start;
long this_round, size;
ssize_t orig_count;
long p = pos;
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;
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;
this_round -= tmp_count;
p = HEADER_SIZE;
con_buf0 = con_buf + HEADER_SIZE;
} else if (p & 1) {
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;
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;
}
}
}
}
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;
}
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;
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;
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;
}
static ssize_t
vcs_read(struct file *file, char *buf, size_t count, loff_t *ppos)
{
struct inode *inode = file->f_dentry->d_inode;
unsigned int currcons = MINOR(inode->i_rdev);
long p = *ppos;
long viewed, attr, size, read;
char *buf0;
int col, maxcol;
unsigned short *org = NULL;
attr = (currcons & 128);
currcons = (currcons & 127);
disable_bh(CONSOLE_BH);
if (currcons == 0) {
currcons = fg_console;
viewed = 1;
} else {
currcons--;
viewed = 0;
}
if (!vc_cons_allocated(currcons))
RETURN( -ENXIO );
size = vcs_size(inode);
if (p < 0 || p > size)
RETURN( -EINVAL );
if (count > size - p)
count = size - p;
buf0 = buf;
maxcol = video_num_columns;
if (!attr) {
org = screen_pos(currcons, p, viewed);
col = p % maxcol;
p += maxcol - col;
while (count-- > 0) {
put_user(vcs_scr_readw(currcons, org++) & 0xff, buf++);
if (++col == maxcol) {
org = screen_pos(currcons, p, viewed);
col = 0;
p += maxcol;
}
}
} else {
if (p < HEADER_SIZE) {
char header[HEADER_SIZE];
header[0] = (char) video_num_lines;
header[1] = (char) video_num_columns;
getconsxy(currcons, header+2);
while (p < HEADER_SIZE && count > 0)
{ count--; put_user(header[p++], buf++); }
}
p -= HEADER_SIZE;
col = (p/2) % maxcol;
if (count > 0) {
org = screen_pos(currcons, p/2, viewed);
if ((p & 1) && count > 0) {
count--;
#ifdef __BIG_ENDIAN
put_user(vcs_scr_readw(currcons, org++) & 0xff, buf++);
#else
put_user(vcs_scr_readw(currcons, org++) >> 8, buf++);
#endif
p++;
if (++col == maxcol) {
org = screen_pos(currcons, p/2, viewed);
col = 0;
}
}
p /= 2;
p += maxcol - col;
}
