[PATCH] console: only bidirectional consoles allow RATP

[Aleksander Morgado]

If a request to switch to RATP mode is received in an input-only
console, ignore the request.

This actually also avoids segfaulting later on:

    #0  0x0000000000000000 in ?? ()
    #1  0x000000000040b2a4 in console_send (r=<optimized out>, pkt=0x7fffffffd8ec, len=4) at common/ratp.c:102
    #2  0x000000000042ab99 in ratp_behaviour_a (pkt=0x7ffff7298780, ri=0x7ffff72766d0) at lib/ratp.c:530
    #3  ratp_state_machine (pkt=0x7ffff7298780, ri=0x7ffff72766d0) at lib/ratp.c:1384
    #4  ratp_poll (ratp=0x7ffff7277ed8) at lib/ratp.c:1561
    #5  0x000000000042b2ab in ratp_establish (ratp=ratp at entry=0x7ffff7277ed8, active=active at entry=false, timeout_ms=timeout_ms at entry=100) at lib/ratp.c:1645
    #6  0x000000000040b888 in barebox_ratp (cdev=cdev at entry=0x7ffff7212bd0) at common/ratp.c:470
    #7  0x00000000004046c3 in getc_raw () at common/console.c:416
    ...

Signed-off-by: Aleksander Morgado <aleksander at aleksander.es>
---

Hey Sascha,

Looks like I may actually need to update the options to allow setting up bidirectional consoles, instead of separate input/output ones. Otherwise I won't be able to use RATP over the FIFO-based console. This patch fixes a segfault happening in barebox sandbox when the input-only console receives a request to switch to RATP mode, it ends up crashing afterwards when the SYN/ACK response is to be sent via the non-existent output path.

Cheers!

---
 common/console.c | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/common/console.c b/common/console.c
index f4c799fa5..f8677659e 100644
--- a/common/console.c
+++ b/common/console.c
@@ -412,7 +412,9 @@ static int getc_raw(void)
 			if (cdev->tstc(cdev)) {
 				int ch = cdev->getc(cdev);

-				if (IS_ENABLED(CONFIG_RATP) && ch == 0x01) {
+				if (IS_ENABLED(CONFIG_RATP) &&
+				    ch == 0x01 &&
+				    (cdev->f_active & CONSOLE_STDOUT)) {
 					barebox_ratp(cdev);
 					return -1;
 				}
--
2.13.0