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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.c77
1 files changed, 36 insertions, 41 deletions
diff --git a/drivers/tty/n_tty.c b/drivers/tty/n_tty.c
index 6c9a408d67..f252d0b5a4 100644
--- a/drivers/tty/n_tty.c
+++ b/drivers/tty/n_tty.c
@@ -249,15 +249,12 @@ static void n_tty_check_throttle(struct tty_struct *tty)
if (ldata->icanon && ldata->canon_head == ldata->read_tail)
return;
- while (1) {
- int throttled;
+ do {
tty_set_flow_change(tty, TTY_THROTTLE_SAFE);
if (N_TTY_BUF_SIZE - read_cnt(ldata) >= TTY_THRESHOLD_THROTTLE)
break;
- throttled = tty_throttle_safe(tty);
- if (!throttled)
- break;
- }
+ } while (!tty_throttle_safe(tty));
+
__tty_set_flow_change(tty, 0);
}
@@ -279,16 +276,14 @@ static void n_tty_check_unthrottle(struct tty_struct *tty)
* we won't get any more characters.
*/
- while (1) {
- int unthrottled;
+ do {
tty_set_flow_change(tty, TTY_UNTHROTTLE_SAFE);
if (chars_in_buffer(tty) > TTY_THRESHOLD_UNTHROTTLE)
break;
+
n_tty_kick_worker(tty);
- unthrottled = tty_unthrottle_safe(tty);
- if (!unthrottled)
- break;
- }
+ } while (!tty_unthrottle_safe(tty));
+
__tty_set_flow_change(tty, 0);
}
@@ -1965,26 +1960,27 @@ static bool copy_from_read_buf(const struct tty_struct *tty, u8 **kbp,
size_t head = smp_load_acquire(&ldata->commit_head);
size_t tail = MASK(ldata->read_tail);
- n = min(head - ldata->read_tail, N_TTY_BUF_SIZE - tail);
- n = min(*nr, n);
- if (n) {
- u8 *from = read_buf_addr(ldata, tail);
- memcpy(*kbp, from, n);
- is_eof = n == 1 && *from == EOF_CHAR(tty);
- tty_audit_add_data(tty, from, n);
- zero_buffer(tty, from, n);
- smp_store_release(&ldata->read_tail, ldata->read_tail + n);
- /* Turn single EOF into zero-length read */
- if (L_EXTPROC(tty) && ldata->icanon && is_eof &&
- (head == ldata->read_tail))
- return false;
- *kbp += n;
- *nr -= n;
-
- /* If we have more to copy, let the caller know */
- return head != ldata->read_tail;
- }
- return false;
+ n = min3(head - ldata->read_tail, N_TTY_BUF_SIZE - tail, *nr);
+ if (!n)
+ return false;
+
+ u8 *from = read_buf_addr(ldata, tail);
+ memcpy(*kbp, from, n);
+ is_eof = n == 1 && *from == EOF_CHAR(tty);
+ tty_audit_add_data(tty, from, n);
+ zero_buffer(tty, from, n);
+ smp_store_release(&ldata->read_tail, ldata->read_tail + n);
+
+ /* Turn single EOF into zero-length read */
+ if (L_EXTPROC(tty) && ldata->icanon && is_eof &&
+ head == ldata->read_tail)
+ return false;
+
+ *kbp += n;
+ *nr -= n;
+
+ /* If we have more to copy, let the caller know */
+ return head != ldata->read_tail;
}
/**
@@ -2154,9 +2150,8 @@ static ssize_t n_tty_read(struct tty_struct *tty, struct file *file, u8 *kbuf,
struct n_tty_data *ldata = tty->disc_data;
u8 *kb = kbuf;
DEFINE_WAIT_FUNC(wait, woken_wake_function);
- int c;
int minimum, time;
- ssize_t retval = 0;
+ ssize_t retval;
long timeout;
bool packet;
size_t old_tail;
@@ -2192,9 +2187,9 @@ static ssize_t n_tty_read(struct tty_struct *tty, struct file *file, u8 *kbuf,
return kb - kbuf;
}
- c = job_control(tty, file);
- if (c < 0)
- return c;
+ retval = job_control(tty, file);
+ if (retval < 0)
+ return retval;
/*
* Internal serialization of reads.
@@ -2499,7 +2494,7 @@ static int n_tty_ioctl(struct tty_struct *tty, unsigned int cmd,
unsigned long arg)
{
struct n_tty_data *ldata = tty->disc_data;
- int retval;
+ unsigned int num;
switch (cmd) {
case TIOCOUTQ:
@@ -2507,11 +2502,11 @@ static int n_tty_ioctl(struct tty_struct *tty, unsigned int cmd,
case TIOCINQ:
down_write(&tty->termios_rwsem);
if (L_ICANON(tty) && !L_EXTPROC(tty))
- retval = inq_canon(ldata);
+ num = inq_canon(ldata);
else
- retval = read_cnt(ldata);
+ num = read_cnt(ldata);
up_write(&tty->termios_rwsem);
- return put_user(retval, (unsigned int __user *) arg);
+ return put_user(num, (unsigned int __user *) arg);
default:
return n_tty_ioctl_helper(tty, cmd, arg);
}