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path: root/drivers/tty/n_tty.c
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Diffstat (limited to 'drivers/tty/n_tty.c')
-rw-r--r--drivers/tty/n_tty.c82
1 files changed, 34 insertions, 48 deletions
diff --git a/drivers/tty/n_tty.c b/drivers/tty/n_tty.c
index 7e5e36315260..4a34a9f43b29 100644
--- a/drivers/tty/n_tty.c
+++ b/drivers/tty/n_tty.c
@@ -164,29 +164,24 @@ static void zero_buffer(struct tty_struct *tty, u8 *buffer, int size)
memset(buffer, 0x00, size);
}
-static int tty_copy_to_user(struct tty_struct *tty, void __user *to,
- size_t tail, size_t n)
+static void tty_copy(struct tty_struct *tty, void *to, size_t tail, size_t n)
{
struct n_tty_data *ldata = tty->disc_data;
size_t size = N_TTY_BUF_SIZE - tail;
void *from = read_buf_addr(ldata, tail);
- int uncopied;
if (n > size) {
tty_audit_add_data(tty, from, size);
- uncopied = copy_to_user(to, from, size);
- zero_buffer(tty, from, size - uncopied);
- if (uncopied)
- return uncopied;
+ memcpy(to, from, size);
+ zero_buffer(tty, from, size);
to += size;
n -= size;
from = ldata->read_buf;
}
tty_audit_add_data(tty, from, n);
- uncopied = copy_to_user(to, from, n);
- zero_buffer(tty, from, n - uncopied);
- return uncopied;
+ memcpy(to, from, n);
+ zero_buffer(tty, from, n);
}
/**
@@ -1942,15 +1937,16 @@ static inline int input_available_p(struct tty_struct *tty, int poll)
/**
* copy_from_read_buf - copy read data directly
* @tty: terminal device
- * @b: user data
+ * @kbp: data
* @nr: size of data
*
* Helper function to speed up n_tty_read. It is only called when
- * ICANON is off; it copies characters straight from the tty queue to
- * user space directly. It can be profitably called twice; once to
- * drain the space from the tail pointer to the (physical) end of the
- * buffer, and once to drain the space from the (physical) beginning of
- * the buffer to head pointer.
+ * ICANON is off; it copies characters straight from the tty queue.
+ *
+ * It can be profitably called twice; once to drain the space from
+ * the tail pointer to the (physical) end of the buffer, and once
+ * to drain the space from the (physical) beginning of the buffer
+ * to head pointer.
*
* Called under the ldata->atomic_read_lock sem
*
@@ -1960,7 +1956,7 @@ static inline int input_available_p(struct tty_struct *tty, int poll)
*/
static int copy_from_read_buf(struct tty_struct *tty,
- unsigned char __user **b,
+ unsigned char **kbp,
size_t *nr)
{
@@ -1976,8 +1972,7 @@ static int copy_from_read_buf(struct tty_struct *tty,
n = min(*nr, n);
if (n) {
unsigned char *from = read_buf_addr(ldata, tail);
- retval = copy_to_user(*b, from, n);
- n -= retval;
+ memcpy(*kbp, from, n);
is_eof = n == 1 && *from == EOF_CHAR(tty);
tty_audit_add_data(tty, from, n);
zero_buffer(tty, from, n);
@@ -1986,7 +1981,7 @@ static int copy_from_read_buf(struct tty_struct *tty,
if (L_EXTPROC(tty) && ldata->icanon && is_eof &&
(head == ldata->read_tail))
n = 0;
- *b += n;
+ *kbp += n;
*nr -= n;
}
return retval;
@@ -1995,12 +1990,12 @@ static int copy_from_read_buf(struct tty_struct *tty,
/**
* canon_copy_from_read_buf - copy read data in canonical mode
* @tty: terminal device
- * @b: user data
+ * @kbp: data
* @nr: size of data
*
* Helper function for n_tty_read. It is only called when ICANON is on;
* it copies one line of input up to and including the line-delimiting
- * character into the user-space buffer.
+ * character into the result buffer.
*
* NB: When termios is changed from non-canonical to canonical mode and
* the read buffer contains data, n_tty_set_termios() simulates an EOF
@@ -2016,14 +2011,14 @@ static int copy_from_read_buf(struct tty_struct *tty,
*/
static int canon_copy_from_read_buf(struct tty_struct *tty,
- unsigned char __user **b,
+ unsigned char **kbp,
size_t *nr)
{
struct n_tty_data *ldata = tty->disc_data;
size_t n, size, more, c;
size_t eol;
size_t tail;
- int ret, found = 0;
+ int found = 0;
/* N.B. avoid overrun if nr == 0 */
if (!*nr)
@@ -2059,10 +2054,8 @@ static int canon_copy_from_read_buf(struct tty_struct *tty,
n_tty_trace("%s: eol:%zu found:%d n:%zu c:%zu tail:%zu more:%zu\n",
__func__, eol, found, n, c, tail, more);
- ret = tty_copy_to_user(tty, *b, tail, n);
- if (ret)
- return -EFAULT;
- *b += n;
+ tty_copy(tty, *kbp, tail, n);
+ *kbp += n;
*nr -= n;
if (found)
@@ -2130,10 +2123,11 @@ static int job_control(struct tty_struct *tty, struct file *file)
*/
static ssize_t n_tty_read(struct tty_struct *tty, struct file *file,
- unsigned char __user *buf, size_t nr)
+ unsigned char *kbuf, size_t nr,
+ void **cookie, unsigned long offset)
{
struct n_tty_data *ldata = tty->disc_data;
- unsigned char __user *b = buf;
+ unsigned char *kb = kbuf;
DEFINE_WAIT_FUNC(wait, woken_wake_function);
int c;
int minimum, time;
@@ -2179,17 +2173,13 @@ static ssize_t n_tty_read(struct tty_struct *tty, struct file *file,
/* First test for status change. */
if (packet && tty->link->ctrl_status) {
unsigned char cs;
- if (b != buf)
+ if (kb != kbuf)
break;
spin_lock_irq(&tty->link->ctrl_lock);
cs = tty->link->ctrl_status;
tty->link->ctrl_status = 0;
spin_unlock_irq(&tty->link->ctrl_lock);
- if (put_user(cs, b)) {
- retval = -EFAULT;
- break;
- }
- b++;
+ *kb++ = cs;
nr--;
break;
}
@@ -2232,24 +2222,20 @@ static ssize_t n_tty_read(struct tty_struct *tty, struct file *file,
}
if (ldata->icanon && !L_EXTPROC(tty)) {
- retval = canon_copy_from_read_buf(tty, &b, &nr);
+ retval = canon_copy_from_read_buf(tty, &kb, &nr);
if (retval)
break;
} else {
int uncopied;
/* Deal with packet mode. */
- if (packet && b == buf) {
- if (put_user(TIOCPKT_DATA, b)) {
- retval = -EFAULT;
- break;
- }
- b++;
+ if (packet && kb == kbuf) {
+ *kb++ = TIOCPKT_DATA;
nr--;
}
- uncopied = copy_from_read_buf(tty, &b, &nr);
- uncopied += copy_from_read_buf(tty, &b, &nr);
+ uncopied = copy_from_read_buf(tty, &kb, &nr);
+ uncopied += copy_from_read_buf(tty, &kb, &nr);
if (uncopied) {
retval = -EFAULT;
break;
@@ -2258,7 +2244,7 @@ static ssize_t n_tty_read(struct tty_struct *tty, struct file *file,
n_tty_check_unthrottle(tty);
- if (b - buf >= minimum)
+ if (kb - kbuf >= minimum)
break;
if (time)
timeout = time;
@@ -2270,8 +2256,8 @@ static ssize_t n_tty_read(struct tty_struct *tty, struct file *file,
remove_wait_queue(&tty->read_wait, &wait);
mutex_unlock(&ldata->atomic_read_lock);
- if (b - buf)
- retval = b - buf;
+ if (kb - kbuf)
+ retval = kb - kbuf;
return retval;
}
generated by cgit v1.2.3 (git 2.39.1) at 2024-12-22 13:41:36 +0000