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Merge tag 'tty-5.12-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty

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Pull tty/serial driver updates from Greg KH:
 "Here is the big set of tty/serial driver changes for 5.12-rc1.

  Nothing huge, just lots of good cleanups and additions:

   - n_tty line discipline cleanups

   - vt core cleanups and reworks to make the code more "modern"

   - stm32 driver additions

   - tty led support added to the tty core and led layer

   - minor serial driver fixups and additions

  All of these have been in linux-next for a while with no reported
  issues"

* tag 'tty-5.12-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty: (54 commits)
  serial: core: Remove BUG_ON(in_interrupt()) check
  vt_ioctl: Remove in_interrupt() check
  dt-bindings: serial: imx: Switch to my personal address
  vt: keyboard, use new API for keyboard_tasklet
  serial: stm32: improve platform_get_irq condition handling in init_port
  serial: ifx6x60: Remove driver for deprecated platform
  tty: fix up iterate_tty_read() EOVERFLOW handling
  tty: fix up hung_up_tty_read() conversion
  tty: fix up hung_up_tty_write() conversion
  tty: teach the n_tty ICANON case about the new "cookie continuations" too
  tty: teach n_tty line discipline about the new "cookie continuations"
  tty: clean up legacy leftovers from n_tty line discipline
  tty: implement read_iter
  tty: convert tty_ldisc_ops 'read()' function to take a kernel pointer
  serial: remove sirf prima/atlas driver
  serial: mxs-auart: Remove <asm/cacheflush.h>
  serial: mxs-auart: Remove serial_mxs_probe_dt()
  serial: fsl_lpuart: Use of_device_get_match_data()
  dt-bindings: serial: renesas,hscif: Add r8a779a0 support
  tty: serial: Drop unused efm32 serial driver
  ...
This commit is contained in:
Linus Torvalds
2021-02-20 21:28:04 -08:00
parent 3342ff2698 a157270fbf
commit e4286926ab
70 changed files with 958 additions and 5187 deletions
Download Patch File Download Diff File Expand all files Collapse all files

153
drivers/tty/n_tty.c
View File

@ -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);
}
/**
@ -1894,8 +1889,10 @@ static void n_tty_close(struct tty_struct *tty)
if (tty->link)
n_tty_packet_mode_flush(tty);
down_write(&tty->termios_rwsem);
vfree(ldata);
tty->disc_data = NULL;
up_write(&tty->termios_rwsem);
}
/**
@ -1944,42 +1941,38 @@ 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.
*
* Called under the ldata->atomic_read_lock sem
*
* Returns true if it successfully copied data, but there is still
* more data to be had.
*
* n_tty_read()/consumer path:
* caller holds non-exclusive termios_rwsem
* read_tail published
*/
static int copy_from_read_buf(struct tty_struct *tty,
unsigned char __user **b,
static bool copy_from_read_buf(struct tty_struct *tty,
unsigned char **kbp,
size_t *nr)
{
struct n_tty_data *ldata = tty->disc_data;
int retval;
size_t n;
bool is_eof;
size_t head = smp_load_acquire(&ldata->commit_head);
size_t tail = ldata->read_tail & (N_TTY_BUF_SIZE - 1);
retval = 0;
n = min(head - ldata->read_tail, N_TTY_BUF_SIZE - tail);
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);
@ -1987,22 +1980,25 @@ static int copy_from_read_buf(struct tty_struct *tty,
/* Turn single EOF into zero-length read */
if (L_EXTPROC(tty) && ldata->icanon && is_eof &&
(head == ldata->read_tail))
n = 0;
*b += n;
return false;
*kbp += n;
*nr -= n;
/* If we have more to copy, let the caller know */
return head != ldata->read_tail;
}
return retval;
return false;
}
/**
* 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
@ -2017,21 +2013,22 @@ static int copy_from_read_buf(struct tty_struct *tty,
* read_tail published
*/
static int canon_copy_from_read_buf(struct tty_struct *tty,
unsigned char __user **b,
size_t *nr)
static bool canon_copy_from_read_buf(struct tty_struct *tty,
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;
size_t tail, canon_head;
int found = 0;
/* N.B. avoid overrun if nr == 0 */
if (!*nr)
return 0;
return false;
n = min(*nr + 1, smp_load_acquire(&ldata->canon_head) - ldata->read_tail);
canon_head = smp_load_acquire(&ldata->canon_head);
n = min(*nr + 1, canon_head - ldata->read_tail);
tail = ldata->read_tail & (N_TTY_BUF_SIZE - 1);
size = min_t(size_t, tail + n, N_TTY_BUF_SIZE);
@ -2061,10 +2058,8 @@ 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)
@ -2077,8 +2072,11 @@ static int canon_copy_from_read_buf(struct tty_struct *tty,
else
ldata->push = 0;
tty_audit_push();
return false;
}
return 0;
/* No EOL found - do a continuation retry if there is more data */
return ldata->read_tail != canon_head;
}
/**
@ -2129,10 +2127,11 @@ 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;
@ -2141,6 +2140,30 @@ static ssize_t n_tty_read(struct tty_struct *tty, struct file *file,
int packet;
size_t tail;
/*
* Is this a continuation of a read started earler?
*
* If so, we still hold the atomic_read_lock and the
* termios_rwsem, and can just continue to copy data.
*/
if (*cookie) {
if (ldata->icanon && !L_EXTPROC(tty)) {
if (canon_copy_from_read_buf(tty, &kb, &nr))
return kb - kbuf;
} else {
if (copy_from_read_buf(tty, &kb, &nr))
return kb - kbuf;
}
/* No more data - release locks and stop retries */
n_tty_kick_worker(tty);
n_tty_check_unthrottle(tty);
up_read(&tty->termios_rwsem);
mutex_unlock(&ldata->atomic_read_lock);
*cookie = NULL;
return kb - kbuf;
}
c = job_control(tty, file);
if (c < 0)
return c;
@ -2178,17 +2201,13 @@ 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;
}
@ -2231,33 +2250,35 @@ 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);
if (retval)
break;
if (canon_copy_from_read_buf(tty, &kb, &nr))
goto more_to_be_read;
} 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);
if (uncopied) {
retval = -EFAULT;
break;
/*
* Copy data, and if there is more to be had
* and we have nothing more to wait for, then
* let's mark us for retries.
*
* NOTE! We return here with both the termios_sem
* and atomic_read_lock still held, the retries
* will release them when done.
*/
if (copy_from_read_buf(tty, &kb, &nr) && kb - kbuf >= minimum) {
more_to_be_read:
remove_wait_queue(&tty->read_wait, &wait);
*cookie = cookie;
return kb - kbuf;
}
}
n_tty_check_unthrottle(tty);
if (b - buf >= minimum)
if (kb - kbuf >= minimum)
break;
if (time)
timeout = time;
@ -2269,8 +2290,8 @@ 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;
}