From 15a102e062af18e01daece409ee54765a3b4ec13 Mon Sep 17 00:00:00 2001 From: Kevin O'Connor Date: Wed, 19 Jan 2022 19:07:47 -0500 Subject: sercon: Fix missing GET_LOW() to access rx_bytes MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit The variable rx_bytes is marked VARLOW, but there was a missing GET_LOW() to access rx_bytes. Fix by copying rx_bytes to a local variable and avoid the repetitive segment memory accesses. Reported-by: Gabe Black Signed-off-by: Volker Rümelin Signed-off-by: Kevin O'Connor --- src/sercon.c | 20 +++++++++++--------- 1 file changed, 11 insertions(+), 9 deletions(-) diff --git a/src/sercon.c b/src/sercon.c index 66a1f241..3019d9b4 100644 --- a/src/sercon.c +++ b/src/sercon.c @@ -626,7 +626,7 @@ sercon_check_event(void) u16 addr = GET_LOW(sercon_port); u16 keycode; u8 byte, count = 0; - int seq, chr; + int seq; // check to see if there is a active serial port if (!addr) @@ -640,20 +640,23 @@ sercon_check_event(void) // read all available data while (inb(addr + SEROFF_LSR) & 0x01) { byte = inb(addr + SEROFF_DATA); - if (GET_LOW(rx_bytes) < sizeof(rx_buf)) { - SET_LOW(rx_buf[rx_bytes], byte); - SET_LOW(rx_bytes, GET_LOW(rx_bytes) + 1); + u8 rb = GET_LOW(rx_bytes); + if (rb < sizeof(rx_buf)) { + SET_LOW(rx_buf[rb], byte); + SET_LOW(rx_bytes, rb + 1); count++; } } for (;;) { // no (more) input data - if (!GET_LOW(rx_bytes)) + u8 rb = GET_LOW(rx_bytes); + if (!rb) return; // lookup escape sequences - if (GET_LOW(rx_bytes) > 1 && GET_LOW(rx_buf[0]) == 0x1b) { + u8 next_char = GET_LOW(rx_buf[0]); + if (rb > 1 && next_char == 0x1b) { seq = findseq(); if (seq >= 0) { enqueue_key(GET_GLOBAL(termseq[seq].keycode)); @@ -664,12 +667,11 @@ sercon_check_event(void) // Seems we got a escape sequence we didn't recognise. // -> If we received data wait for more, maybe it is just incomplete. - if (GET_LOW(rx_buf[0]) == 0x1b && count) + if (next_char == 0x1b && count) return; // Handle input as individual char. - chr = GET_LOW(rx_buf[0]); - keycode = ascii_to_keycode(chr); + keycode = ascii_to_keycode(next_char); if (keycode) enqueue_key(keycode); shiftbuf(1); -- cgit