#define TTY_THRESHOLD_THROTTLE 128 /* now based on remaining room */
#define TTY_THRESHOLD_UNTHROTTLE 128
+/*
+ * Special byte codes used in the echo buffer to represent operations
+ * or special handling of characters. Bytes in the echo buffer that
+ * are not part of such special blocks are treated as normal character
+ * codes.
+ */
+#define ECHO_OP_START 0xff
+#define ECHO_OP_MOVE_BACK_COL 0x80
+#define ECHO_OP_SET_CANON_COL 0x81
+#define ECHO_OP_ERASE_TAB 0x82
+
static inline unsigned char *alloc_buf(void)
{
gfp_t prio = in_interrupt() ? GFP_ATOMIC : GFP_KERNEL;
*
* Locking: tty_read_lock for read fields.
*/
+
static void reset_buffer_flags(struct tty_struct *tty)
{
unsigned long flags;
spin_lock_irqsave(&tty->read_lock, flags);
tty->read_head = tty->read_tail = tty->read_cnt = 0;
spin_unlock_irqrestore(&tty->read_lock, flags);
+
+ mutex_lock(&tty->echo_lock);
+ tty->echo_pos = tty->echo_cnt = tty->echo_overrun = 0;
+ mutex_unlock(&tty->echo_lock);
+
tty->canon_head = tty->canon_data = tty->erasing = 0;
memset(&tty->read_flags, 0, sizeof tty->read_flags);
n_tty_set_room(tty);
}
/**
- * opost - output post processor
+ * do_output_char - output one character
* @c: character (or partial unicode symbol)
* @tty: terminal device
+ * @space: space available in tty driver write buffer
*
- * Perform OPOST processing. Returns -1 when the output device is
- * full and the character must be retried. Note that Linux currently
- * ignores TABDLY, CRDLY, VTDLY, FFDLY and NLDLY. They simply aren't
- * relevant in the world today. If you ever need them, add them here.
+ * This is a helper function that handles one output character
+ * (including special characters like TAB, CR, LF, etc.),
+ * putting the results in the tty driver's write buffer.
+ *
+ * Note that Linux currently ignores TABDLY, CRDLY, VTDLY, FFDLY
+ * and NLDLY. They simply aren't relevant in the world today.
+ * If you ever need them, add them here.
*
- * Called from both the receive and transmit sides and can be called
- * re-entrantly. Relies on lock_kernel() for tty->column state.
+ * Returns the number of bytes of buffer space used or -1 if
+ * no space left.
+ *
+ * Locking: should be called under the output_lock to protect
+ * the column state and space left in the buffer
*/
-static int opost(unsigned char c, struct tty_struct *tty)
+static int do_output_char(unsigned char c, struct tty_struct *tty, int space)
{
- int space, spaces;
+ int spaces;
- space = tty_write_room(tty);
if (!space)
return -1;
-
- lock_kernel();
- if (O_OPOST(tty)) {
- switch (c) {
- case '\n':
- if (O_ONLRET(tty))
- tty->column = 0;
- if (O_ONLCR(tty)) {
- if (space < 2) {
- unlock_kernel();
- return -1;
- }
- tty_put_char(tty, '\r');
- tty->column = 0;
- }
- tty->canon_column = tty->column;
- break;
- case '\r':
- if (O_ONOCR(tty) && tty->column == 0) {
- unlock_kernel();
- return 0;
- }
- if (O_OCRNL(tty)) {
- c = '\n';
- if (O_ONLRET(tty))
- tty->canon_column = tty->column = 0;
- break;
- }
+
+ switch (c) {
+ case '\n':
+ if (O_ONLRET(tty))
+ tty->column = 0;
+ if (O_ONLCR(tty)) {
+ if (space < 2)
+ return -1;
tty->canon_column = tty->column = 0;
+ tty_put_char(tty, '\r');
+ tty_put_char(tty, c);
+ return 2;
+ }
+ tty->canon_column = tty->column;
+ break;
+ case '\r':
+ if (O_ONOCR(tty) && tty->column == 0)
+ return 0;
+ if (O_OCRNL(tty)) {
+ c = '\n';
+ if (O_ONLRET(tty))
+ tty->canon_column = tty->column = 0;
break;
- case '\t':
- spaces = 8 - (tty->column & 7);
- if (O_TABDLY(tty) == XTABS) {
- if (space < spaces) {
- unlock_kernel();
- return -1;
- }
- tty->column += spaces;
- tty->ops->write(tty, " ", spaces);
- unlock_kernel();
- return 0;
- }
+ }
+ tty->canon_column = tty->column = 0;
+ break;
+ case '\t':
+ spaces = 8 - (tty->column & 7);
+ if (O_TABDLY(tty) == XTABS) {
+ if (space < spaces)
+ return -1;
tty->column += spaces;
- break;
- case '\b':
- if (tty->column > 0)
- tty->column--;
- break;
- default:
- if (O_OLCUC(tty))
- c = toupper(c);
- if (!iscntrl(c) && !is_continuation(c, tty))
- tty->column++;
- break;
+ tty->ops->write(tty, " ", spaces);
+ return spaces;
}
+ tty->column += spaces;
+ break;
+ case '\b':
+ if (tty->column > 0)
+ tty->column--;
+ break;
+ default:
+ if (O_OLCUC(tty))
+ c = toupper(c);
+ if (!iscntrl(c) && !is_continuation(c, tty))
+ tty->column++;
+ break;
}
+
tty_put_char(tty, c);
- unlock_kernel();
- return 0;
+ return 1;
+}
+
+/**
+ * process_output - output post processor
+ * @c: character (or partial unicode symbol)
+ * @tty: terminal device
+ *
+ * Perform OPOST processing. Returns -1 when the output device is
+ * full and the character must be retried.
+ *
+ * Locking: output_lock to protect column state and space left
+ * (also, this is called from n_tty_write under the
+ * tty layer write lock)
+ */
+
+static int process_output(unsigned char c, struct tty_struct *tty)
+{
+ int space, retval;
+
+ mutex_lock(&tty->output_lock);
+
+ space = tty_write_room(tty);
+ retval = do_output_char(c, tty, space);
+
+ mutex_unlock(&tty->output_lock);
+ if (retval < 0)
+ return -1;
+ else
+ return 0;
}
/**
- * opost_block - block postprocess
+ * process_output_block - block post processor
* @tty: terminal device
* @inbuf: user buffer
* @nr: number of bytes
* the simple cases normally found and helps to generate blocks of
* symbols for the console driver and thus improve performance.
*
- * Called from n_tty_write under the tty layer write lock. Relies
- * on lock_kernel for the tty->column state.
+ * Locking: output_lock to protect column state and space left
+ * (also, this is called from n_tty_write under the
+ * tty layer write lock)
*/
-static ssize_t opost_block(struct tty_struct *tty,
- const unsigned char *buf, unsigned int nr)
+static ssize_t process_output_block(struct tty_struct *tty,
+ const unsigned char *buf, unsigned int nr)
{
int space;
int i;
const unsigned char *cp;
+ mutex_lock(&tty->output_lock);
+
space = tty_write_room(tty);
if (!space)
+ {
+ mutex_unlock(&tty->output_lock);
return 0;
+ }
if (nr > space)
nr = space;
- lock_kernel();
for (i = 0, cp = buf; i < nr; i++, cp++) {
switch (*cp) {
case '\n':
}
}
break_out:
- if (tty->ops->flush_chars)
- tty->ops->flush_chars(tty);
i = tty->ops->write(tty, buf, i);
- unlock_kernel();
+
+ mutex_unlock(&tty->output_lock);
return i;
}
+/**
+ * process_echoes - write pending echo characters
+ * @tty: terminal device
+ *
+ * Write previously buffered echo (and other ldisc-generated)
+ * characters to the tty.
+ *
+ * Characters generated by the ldisc (including echoes) need to
+ * be buffered because the driver's write buffer can fill during
+ * heavy program output. Echoing straight to the driver will
+ * often fail under these conditions, causing lost characters and
+ * resulting mismatches of ldisc state information.
+ *
+ * Since the ldisc state must represent the characters actually sent
+ * to the driver at the time of the write, operations like certain
+ * changes in column state are also saved in the buffer and executed
+ * here.
+ *
+ * A circular fifo buffer is used so that the most recent characters
+ * are prioritized. Also, when control characters are echoed with a
+ * prefixed "^", the pair is treated atomically and thus not separated.
+ *
+ * Locking: output_lock to protect column state and space left,
+ * echo_lock to protect the echo buffer
+ */
+
+static void process_echoes(struct tty_struct *tty)
+{
+ int space, nr;
+ unsigned char c;
+ unsigned char *cp, *buf_end;
+
+ if (!tty->echo_cnt)
+ return;
+
+ mutex_lock(&tty->output_lock);
+ mutex_lock(&tty->echo_lock);
+
+ space = tty_write_room(tty);
+
+ buf_end = tty->echo_buf + N_TTY_BUF_SIZE;
+ cp = tty->echo_buf + tty->echo_pos;
+ nr = tty->echo_cnt;
+ while (nr > 0) {
+ c = *cp;
+ if (c == ECHO_OP_START) {
+ unsigned char op;
+ unsigned char *opp;
+ int no_space_left = 0;
+
+ /*
+ * If the buffer byte is the start of a multi-byte
+ * operation, get the next byte, which is either the
+ * op code or a control character value.
+ */
+ opp = cp + 1;
+ if (opp == buf_end)
+ opp -= N_TTY_BUF_SIZE;
+ op = *opp;
+
+ switch (op) {
+ unsigned int num_chars, num_bs;
+
+ case ECHO_OP_ERASE_TAB:
+ if (++opp == buf_end)
+ opp -= N_TTY_BUF_SIZE;
+ num_chars = *opp;
+
+ /*
+ * Determine how many columns to go back
+ * in order to erase the tab.
+ * This depends on the number of columns
+ * used by other characters within the tab
+ * area. If this (modulo 8) count is from
+ * the start of input rather than from a
+ * previous tab, we offset by canon column.
+ * Otherwise, tab spacing is normal.
+ */
+ if (!(num_chars & 0x80))
+ num_chars += tty->canon_column;
+ num_bs = 8 - (num_chars & 7);
+
+ if (num_bs > space) {
+ no_space_left = 1;
+ break;
+ }
+ space -= num_bs;
+ while (num_bs--) {
+ tty_put_char(tty, '\b');
+ if (tty->column > 0)
+ tty->column--;
+ }
+ cp += 3;
+ nr -= 3;
+ break;
+
+ case ECHO_OP_SET_CANON_COL:
+ tty->canon_column = tty->column;
+ cp += 2;
+ nr -= 2;
+ break;
+
+ case ECHO_OP_MOVE_BACK_COL:
+ if (tty->column > 0)
+ tty->column--;
+ cp += 2;
+ nr -= 2;
+ break;
+
+ case ECHO_OP_START:
+ /* This is an escaped echo op start code */
+ if (!space) {
+ no_space_left = 1;
+ break;
+ }
+ tty_put_char(tty, ECHO_OP_START);
+ tty->column++;
+ space--;
+ cp += 2;
+ nr -= 2;
+ break;
+
+ default:
+ if (iscntrl(op)) {
+ if (L_ECHOCTL(tty)) {
+ /*
+ * Ensure there is enough space
+ * for the whole ctrl pair.
+ */
+ if (space < 2) {
+ no_space_left = 1;
+ break;
+ }
+ tty_put_char(tty, '^');
+ tty_put_char(tty, op ^ 0100);
+ tty->column += 2;
+ space -= 2;
+ } else {
+ if (!space) {
+ no_space_left = 1;
+ break;
+ }
+ tty_put_char(tty, op);
+ space--;
+ }
+ }
+ /*
+ * If above falls through, this was an
+ * undefined op.
+ */
+ cp += 2;
+ nr -= 2;
+ }
+
+ if (no_space_left)
+ break;
+ } else {
+ int retval;
+
+ if ((retval = do_output_char(c, tty, space)) < 0)
+ break;
+ space -= retval;
+ cp += 1;
+ nr -= 1;
+ }
+
+ /* When end of circular buffer reached, wrap around */
+ if (cp >= buf_end)
+ cp -= N_TTY_BUF_SIZE;
+ }
+
+ if (nr == 0) {
+ tty->echo_pos = 0;
+ tty->echo_cnt = 0;
+ tty->echo_overrun = 0;
+ } else {
+ int num_processed = tty->echo_cnt - nr;
+ tty->echo_pos += num_processed;
+ tty->echo_pos &= N_TTY_BUF_SIZE - 1;
+ tty->echo_cnt = nr;
+ if (num_processed > 0)
+ tty->echo_overrun = 0;
+ }
+
+ mutex_unlock(&tty->echo_lock);
+ mutex_unlock(&tty->output_lock);
+
+ if (tty->ops->flush_chars)
+ tty->ops->flush_chars(tty);
+}
+
+/**
+ * add_echo_byte - add a byte to the echo buffer
+ * @c: unicode byte to echo
+ * @tty: terminal device
+ *
+ * Add a character or operation byte to the echo buffer.
+ *
+ * Should be called under the echo lock to protect the echo buffer.
+ */
+
+static void add_echo_byte(unsigned char c, struct tty_struct *tty)
+{
+ int new_byte_pos;
+
+ if (tty->echo_cnt == N_TTY_BUF_SIZE) {
+ /* Circular buffer is already at capacity */
+ new_byte_pos = tty->echo_pos;
+
+ /*
+ * Since the buffer start position needs to be advanced,
+ * be sure to step by a whole operation byte group.
+ */
+ if (tty->echo_buf[tty->echo_pos] == ECHO_OP_START)
+ {
+ if (tty->echo_buf[(tty->echo_pos + 1) &
+ (N_TTY_BUF_SIZE - 1)] ==
+ ECHO_OP_ERASE_TAB) {
+ tty->echo_pos += 3;
+ tty->echo_cnt -= 2;
+ } else {
+ tty->echo_pos += 2;
+ tty->echo_cnt -= 1;
+ }
+ } else {
+ tty->echo_pos++;
+ }
+ tty->echo_pos &= N_TTY_BUF_SIZE - 1;
+
+ tty->echo_overrun = 1;
+ } else {
+ new_byte_pos = tty->echo_pos + tty->echo_cnt;
+ new_byte_pos &= N_TTY_BUF_SIZE - 1;
+ tty->echo_cnt++;
+ }
+
+ tty->echo_buf[new_byte_pos] = c;
+}
+
+/**
+ * echo_move_back_col - add operation to move back a column
+ * @tty: terminal device
+ *
+ * Add an operation to the echo buffer to move back one column.
+ *
+ * Locking: echo_lock to protect the echo buffer
+ */
+
+static void echo_move_back_col(struct tty_struct *tty)
+{
+ mutex_lock(&tty->echo_lock);
+
+ add_echo_byte(ECHO_OP_START, tty);
+ add_echo_byte(ECHO_OP_MOVE_BACK_COL, tty);
+
+ mutex_unlock(&tty->echo_lock);
+}
+
+/**
+ * echo_set_canon_col - add operation to set the canon column
+ * @tty: terminal device
+ *
+ * Add an operation to the echo buffer to set the canon column
+ * to the current column.
+ *
+ * Locking: echo_lock to protect the echo buffer
+ */
+
+static void echo_set_canon_col(struct tty_struct *tty)
+{
+ mutex_lock(&tty->echo_lock);
+
+ add_echo_byte(ECHO_OP_START, tty);
+ add_echo_byte(ECHO_OP_SET_CANON_COL, tty);
+
+ mutex_unlock(&tty->echo_lock);
+}
+
+/**
+ * echo_erase_tab - add operation to erase a tab
+ * @num_chars: number of character columns already used
+ * @after_tab: true if num_chars starts after a previous tab
+ * @tty: terminal device
+ *
+ * Add an operation to the echo buffer to erase a tab.
+ *
+ * Called by the eraser function, which knows how many character
+ * columns have been used since either a previous tab or the start
+ * of input. This information will be used later, along with
+ * canon column (if applicable), to go back the correct number
+ * of columns.
+ *
+ * Locking: echo_lock to protect the echo buffer
+ */
+
+static void echo_erase_tab(unsigned int num_chars, int after_tab,
+ struct tty_struct *tty)
+{
+ mutex_lock(&tty->echo_lock);
+
+ add_echo_byte(ECHO_OP_START, tty);
+ add_echo_byte(ECHO_OP_ERASE_TAB, tty);
+
+ /* We only need to know this modulo 8 (tab spacing) */
+ num_chars &= 7;
+
+ /* Set the high bit as a flag if num_chars is after a previous tab */
+ if (after_tab)
+ num_chars |= 0x80;
+
+ add_echo_byte(num_chars, tty);
+
+ mutex_unlock(&tty->echo_lock);
+}
+
+/**
+ * echo_char_raw - echo a character raw
+ * @c: unicode byte to echo
+ * @tty: terminal device
+ *
+ * Echo user input back onto the screen. This must be called only when
+ * L_ECHO(tty) is true. Called from the driver receive_buf path.
+ *
+ * This variant does not treat control characters specially.
+ *
+ * Locking: echo_lock to protect the echo buffer
+ */
+
+static void echo_char_raw(unsigned char c, struct tty_struct *tty)
+{
+ mutex_lock(&tty->echo_lock);
+
+ if (c == ECHO_OP_START) {
+ add_echo_byte(ECHO_OP_START, tty);
+ add_echo_byte(ECHO_OP_START, tty);
+ } else {
+ add_echo_byte(c, tty);
+ }
+
+ mutex_unlock(&tty->echo_lock);
+}
/**
- * echo_char - echo characters
+ * echo_char - echo a character
* @c: unicode byte to echo
* @tty: terminal device
*
* Echo user input back onto the screen. This must be called only when
* L_ECHO(tty) is true. Called from the driver receive_buf path.
*
- * Relies on BKL for tty column locking
+ * This variant tags control characters to be possibly echoed as
+ * as "^X" (where X is the letter representing the control char).
+ *
+ * Locking: echo_lock to protect the echo buffer
*/
static void echo_char(unsigned char c, struct tty_struct *tty)
{
- if (L_ECHOCTL(tty) && iscntrl(c) && c != '\t') {
- tty_put_char(tty, '^');
- tty_put_char(tty, c ^ 0100);
- tty->column += 2;
- } else
- opost(c, tty);
+ mutex_lock(&tty->echo_lock);
+
+ if (c == ECHO_OP_START) {
+ add_echo_byte(ECHO_OP_START, tty);
+ add_echo_byte(ECHO_OP_START, tty);
+ } else {
+ if (iscntrl(c) && c != '\t')
+ add_echo_byte(ECHO_OP_START, tty);
+ add_echo_byte(c, tty);
+ }
+
+ mutex_unlock(&tty->echo_lock);
}
/**
- * finsh_erasing - complete erase
+ * finish_erasing - complete erase
* @tty: tty doing the erase
- *
- * Relies on BKL for tty column locking
*/
+
static inline void finish_erasing(struct tty_struct *tty)
{
if (tty->erasing) {
- tty_put_char(tty, '/');
- tty->column++;
+ echo_char_raw('/', tty);
tty->erasing = 0;
}
}
* present in the stream from the driver layer. Handles the complexities
* of UTF-8 multibyte symbols.
*
- * Locking: read_lock for tty buffers, BKL for column/erasing state
+ * Locking: read_lock for tty buffers
*/
static void eraser(unsigned char c, struct tty_struct *tty)
/* FIXME: locking needed ? */
if (tty->read_head == tty->canon_head) {
- /* opost('\a', tty); */ /* what do you think? */
+ /* echo_char_raw('\a', tty); */ /* what do you think? */
return;
}
if (c == ERASE_CHAR(tty))
echo_char(KILL_CHAR(tty), tty);
/* Add a newline if ECHOK is on and ECHOKE is off. */
if (L_ECHOK(tty))
- opost('\n', tty);
+ echo_char_raw('\n', tty);
return;
}
kill_type = KILL;
if (L_ECHO(tty)) {
if (L_ECHOPRT(tty)) {
if (!tty->erasing) {
- tty_put_char(tty, '\\');
- tty->column++;
+ echo_char_raw('\\', tty);
tty->erasing = 1;
}
/* if cnt > 1, output a multi-byte character */
echo_char(c, tty);
while (--cnt > 0) {
head = (head+1) & (N_TTY_BUF_SIZE-1);
- tty_put_char(tty, tty->read_buf[head]);
+ echo_char_raw(tty->read_buf[head], tty);
+ echo_move_back_col(tty);
}
} else if (kill_type == ERASE && !L_ECHOE(tty)) {
echo_char(ERASE_CHAR(tty), tty);
} else if (c == '\t') {
- unsigned int col = tty->canon_column;
- unsigned long tail = tty->canon_head;
-
- /* Find the column of the last char. */
- while (tail != tty->read_head) {
+ unsigned int num_chars = 0;
+ int after_tab = 0;
+ unsigned long tail = tty->read_head;
+
+ /*
+ * Count the columns used for characters
+ * since the start of input or after a
+ * previous tab.
+ * This info is used to go back the correct
+ * number of columns.
+ */
+ while (tail != tty->canon_head) {
+ tail = (tail-1) & (N_TTY_BUF_SIZE-1);
c = tty->read_buf[tail];
- if (c == '\t')
- col = (col | 7) + 1;
+ if (c == '\t') {
+ after_tab = 1;
+ break;
+ }
else if (iscntrl(c)) {
if (L_ECHOCTL(tty))
- col += 2;
- } else if (!is_continuation(c, tty))
- col++;
- tail = (tail+1) & (N_TTY_BUF_SIZE-1);
- }
-
- /* should never happen */
- if (tty->column > 0x80000000)
- tty->column = 0;
-
- /* Now backup to that column. */
- while (tty->column > col) {
- /* Can't use opost here. */
- tty_put_char(tty, '\b');
- if (tty->column > 0)
- tty->column--;
+ num_chars += 2;
+ } else if (!is_continuation(c, tty)) {
+ num_chars++;
+ }
}
+ echo_erase_tab(num_chars, after_tab, tty);
} else {
if (iscntrl(c) && L_ECHOCTL(tty)) {
- tty_put_char(tty, '\b');
- tty_put_char(tty, ' ');
- tty_put_char(tty, '\b');
- if (tty->column > 0)
- tty->column--;
+ echo_char_raw('\b', tty);
+ echo_char_raw(' ', tty);
+ echo_char_raw('\b', tty);
}
if (!iscntrl(c) || L_ECHOCTL(tty)) {
- tty_put_char(tty, '\b');
- tty_put_char(tty, ' ');
- tty_put_char(tty, '\b');
- if (tty->column > 0)
- tty->column--;
+ echo_char_raw('\b', tty);
+ echo_char_raw(' ', tty);
+ echo_char_raw('\b', tty);
}
}
}
if (kill_type == ERASE)
break;
}
- if (tty->read_head == tty->canon_head)
+ if (tty->read_head == tty->canon_head && L_ECHO(tty))
finish_erasing(tty);
}
c=tolower(c);
if (tty->stopped && !tty->flow_stopped && I_IXON(tty) &&
- ((I_IXANY(tty) && c != START_CHAR(tty) && c != STOP_CHAR(tty)) ||
- c == INTR_CHAR(tty) || c == QUIT_CHAR(tty) || c == SUSP_CHAR(tty)))
+ I_IXANY(tty) && c != START_CHAR(tty) && c != STOP_CHAR(tty) &&
+ c != INTR_CHAR(tty) && c != QUIT_CHAR(tty) && c != SUSP_CHAR(tty)) {
start_tty(tty);
+ process_echoes(tty);
+ }
if (tty->closing) {
if (I_IXON(tty)) {
- if (c == START_CHAR(tty))
+ if (c == START_CHAR(tty)) {
start_tty(tty);
+ process_echoes(tty);
+ }
else if (c == STOP_CHAR(tty))
stop_tty(tty);
}
* up.
*/
if (!test_bit(c, tty->process_char_map) || tty->lnext) {
- finish_erasing(tty);
tty->lnext = 0;
if (L_ECHO(tty)) {
+ finish_erasing(tty);
if (tty->read_cnt >= N_TTY_BUF_SIZE-1) {
- tty_put_char(tty, '\a'); /* beep if no space */
+ /* beep if no space */
+ echo_char_raw('\a', tty);
+ process_echoes(tty);
return;
}
/* Record the column of first canon char. */
if (tty->canon_head == tty->read_head)
- tty->canon_column = tty->column;
+ echo_set_canon_col(tty);
echo_char(c, tty);
+ process_echoes(tty);
}
if (I_PARMRK(tty) && c == (unsigned char) '\377')
put_tty_queue(c, tty);
if (I_IXON(tty)) {
if (c == START_CHAR(tty)) {
start_tty(tty);
+ process_echoes(tty);
return;
}
if (c == STOP_CHAR(tty)) {
if (c == SUSP_CHAR(tty)) {
send_signal:
/*
- * Echo character, and then send the signal.
* Note that we do not use isig() here because we want
* the order to be:
* 1) flush, 2) echo, 3) signal
n_tty_flush_buffer(tty);
tty_driver_flush_buffer(tty);
}
- if (L_ECHO(tty))
+ if (I_IXON(tty))
+ start_tty(tty);
+ if (L_ECHO(tty)) {
echo_char(c, tty);
+ process_echoes(tty);
+ }
if (tty->pgrp)
kill_pgrp(tty->pgrp, signal, 1);
return;
if (c == ERASE_CHAR(tty) || c == KILL_CHAR(tty) ||
(c == WERASE_CHAR(tty) && L_IEXTEN(tty))) {
eraser(c, tty);
+ process_echoes(tty);
return;
}
if (c == LNEXT_CHAR(tty) && L_IEXTEN(tty)) {
if (L_ECHO(tty)) {
finish_erasing(tty);
if (L_ECHOCTL(tty)) {
- tty_put_char(tty, '^');
- tty_put_char(tty, '\b');
+ echo_char_raw('^', tty);
+ echo_char_raw('\b', tty);
+ process_echoes(tty);
}
}
return;
finish_erasing(tty);
echo_char(c, tty);
- opost('\n', tty);
+ echo_char_raw('\n', tty);
while (tail != tty->read_head) {
echo_char(tty->read_buf[tail], tty);
tail = (tail+1) & (N_TTY_BUF_SIZE-1);
}
+ process_echoes(tty);
return;
}
if (c == '\n') {
if (L_ECHO(tty) || L_ECHONL(tty)) {
if (tty->read_cnt >= N_TTY_BUF_SIZE-1)
- tty_put_char(tty, '\a');
- opost('\n', tty);
+ echo_char_raw('\a', tty);
+ echo_char_raw('\n', tty);
+ process_echoes(tty);
}
goto handle_newline;
}
*/
if (L_ECHO(tty)) {
if (tty->read_cnt >= N_TTY_BUF_SIZE-1)
- tty_put_char(tty, '\a');
+ echo_char_raw('\a', tty);
/* Record the column of first canon char. */
if (tty->canon_head == tty->read_head)
- tty->canon_column = tty->column;
+ echo_set_canon_col(tty);
echo_char(c, tty);
+ process_echoes(tty);
}
/*
* XXX does PARMRK doubling happen for
}
}
- finish_erasing(tty);
if (L_ECHO(tty)) {
+ finish_erasing(tty);
if (tty->read_cnt >= N_TTY_BUF_SIZE-1) {
- tty_put_char(tty, '\a'); /* beep if no space */
+ /* beep if no space */
+ echo_char_raw('\a', tty);
+ process_echoes(tty);
return;
}
if (c == '\n')
- opost('\n', tty);
+ echo_char_raw('\n', tty);
else {
/* Record the column of first canon char. */
if (tty->canon_head == tty->read_head)
- tty->canon_column = tty->column;
+ echo_set_canon_col(tty);
echo_char(c, tty);
}
+ process_echoes(tty);
}
if (I_PARMRK(tty) && c == (unsigned char) '\377')
static void n_tty_write_wakeup(struct tty_struct *tty)
{
+ /* Write out any echoed characters that are still pending */
+ process_echoes(tty);
+
if (tty->fasync) {
set_bit(TTY_DO_WRITE_WAKEUP, &tty->flags);
kill_fasync(&tty->fasync, SIGIO, POLL_OUT);
free_buf(tty->read_buf);
tty->read_buf = NULL;
}
+ if (tty->echo_buf) {
+ free_buf(tty->echo_buf);
+ tty->echo_buf = NULL;
+ }
}
/**
if (!tty)
return -EINVAL;
- /* This one is ugly. Currently a malloc failure here can panic */
+ /* These are ugly. Currently a malloc failure here can panic */
if (!tty->read_buf) {
tty->read_buf = alloc_buf();
if (!tty->read_buf)
return -ENOMEM;
}
+ if (!tty->echo_buf) {
+ tty->echo_buf = alloc_buf();
+ if (!tty->echo_buf)
+ return -ENOMEM;
+ }
memset(tty->read_buf, 0, N_TTY_BUF_SIZE);
+ memset(tty->echo_buf, 0, N_TTY_BUF_SIZE);
reset_buffer_flags(tty);
tty->column = 0;
n_tty_set_termios(tty, NULL);
* @buf: userspace buffer pointer
* @nr: size of I/O
*
- * Write function of the terminal device. This is serialized with
+ * Write function of the terminal device. This is serialized with
* respect to other write callers but not to termios changes, reads
- * and other such events. We must be careful with N_TTY as the receive
- * code will echo characters, thus calling driver write methods.
+ * and other such events. Since the receive code will echo characters,
+ * thus calling driver write methods, the output_lock is used in
+ * the output processing functions called here as well as in the
+ * echo processing function to protect the column state and space
+ * left in the buffer.
*
* This code must be sure never to sleep through a hangup.
+ *
+ * Locking: output_lock to protect column state and space left
+ * (note that the process_output*() functions take this
+ * lock themselves)
*/
static ssize_t n_tty_write(struct tty_struct *tty, struct file *file,
- const unsigned char *buf, size_t nr)
+ const unsigned char *buf, size_t nr)
{
const unsigned char *b = buf;
DECLARE_WAITQUEUE(wait, current);
return retval;
}
+ /* Write out any echoed characters that are still pending */
+ process_echoes(tty);
+
add_wait_queue(&tty->write_wait, &wait);
while (1) {
set_current_state(TASK_INTERRUPTIBLE);
}
if (O_OPOST(tty) && !(test_bit(TTY_HW_COOK_OUT, &tty->flags))) {
while (nr > 0) {
- ssize_t num = opost_block(tty, b, nr);
+ ssize_t num = process_output_block(tty, b, nr);
if (num < 0) {
if (num == -EAGAIN)
break;
if (nr == 0)
break;
c = *b;
- if (opost(c, tty) < 0)
+ if (process_output(c, tty) < 0)
break;
b++; nr--;
}
.receive_buf = n_tty_receive_buf,
.write_wakeup = n_tty_write_wakeup
};
-
projects / mirror_ubuntu-eoan-kernel.git / commitdiff