hw/sd/sdcard: Do not abort when reading DAT lines on invalid cmd state

Guest should not try to read the DAT lines from invalid
command state. If it still insists to do so, return a
dummy value.

Cc: qemu-stable@nongnu.org
Fixes: e2dec2eab0 ("hw/sd/sdcard: Remove default case in read/write on DAT lines")
Reported-by: Zheyu Ma <zheyuma97@gmail.com>
Resolves: https://gitlab.com/qemu-project/qemu/-/issues/2454
Signed-off-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-Id: <20240730092138.32443-3-philmd@linaro.org>

diff --git a/hw/sd/sd.c b/hw/sd/sd.c
index de27e34fc869c79892f60da924b1205be66edd58..a140a32ccd4695a700bf5bb54188e8303df6951f 100644 (file)
--- a/hw/sd/sd.c
+++ b/hw/sd/sd.c
@@ -2540,7 +2540,9 @@ uint8_t sd_read_byte(SDState *sd)
         break;
 
     default:
-        g_assert_not_reached();
+        qemu_log_mask(LOG_GUEST_ERROR, "%s: DAT read illegal for command %s\n",
+                                       __func__, sd->last_cmd_name);
+        return dummy_byte;
     }
 
     return ret;