Messages in this thread Patch in this message | | | From | "Jiri Slaby (SUSE)" <> | Subject | [PATCH 04/15] tty: n_tty: invert the condition in copy_from_read_buf() | Date | Tue, 19 Sep 2023 10:51:45 +0200 |
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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> --- drivers/tty/n_tty.c | 38 ++++++++++++++++++++------------------ 1 file 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; } /** -- 2.42.0
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