diff options
| author | Jiri Slaby (SUSE) <jirislaby@kernel.org> | 2023-09-19 10:51:45 +0200 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2023-10-03 14:31:15 +0200 |
| commit | c2b0fb9f69987ddec6bf21f95157603ea4c83aff (patch) | |
| tree | 04cc5036a8e7cd7c273fcdf0180dbea9f9a49b59 | |
| parent | 72369f2d493d4c0f4f0ed5a66b19c6912c4837ef (diff) | |
tty: n_tty: invert the condition in copy_from_read_buf()
Make "no numbers available" a fast quit from the function. And do the
heavy work outside the 'if'. This makes the code more understandable and
conforming to the common kernel coding style.
Signed-off-by: "Jiri Slaby (SUSE)" <jirislaby@kernel.org>
Reviewed-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Link: https://lore.kernel.org/r/20230919085156.1578-5-jirislaby@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| -rw-r--r-- | drivers/tty/n_tty.c | 38 |
1 files changed, 20 insertions, 18 deletions
diff --git a/drivers/tty/n_tty.c b/drivers/tty/n_tty.c index 6a112910c058..922fb61b587a 100644 --- a/drivers/tty/n_tty.c +++ b/drivers/tty/n_tty.c @@ -1966,24 +1966,26 @@ static bool copy_from_read_buf(const struct tty_struct *tty, u8 **kbp, size_t tail = MASK(ldata->read_tail); n = min3(head - ldata->read_tail, N_TTY_BUF_SIZE - tail, *nr); - 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; + 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; } /** |