target: fix registers reading from non examined target

If a target is not examined when the debugger tries to connect to it
then it can lead to undesired/undefined behavior.

In particular it leads to a zero pointer dereference on the aarch64.

Change-Id: I67f2b714ab8b2727fd36f3de16d7f9017b4c55fe
Signed-off-by: Mikhail Rasputin <mikhail.godlike.rasputin@yandex.ru>
Reviewed-on: http://openocd.zylin.com/5727
Tested-by: jenkins
Reviewed-by: Tomas Vanek <vanekt@fbl.cz>
Reviewed-by: Antonio Borneo <borneo.antonio@gmail.com>

diff --git a/src/target/target.c b/src/target/target.c
index b39254826d5beef82b1a0a0b72cb0a3b67f2a166..5efa088b2d72d5c28294aa5348bee8e8918edaf1 100644 (file)
--- a/src/target/target.c
+++ b/src/target/target.c
@@ -1224,8 +1224,17 @@ int target_get_gdb_reg_list(struct target *target,
                struct reg **reg_list[], int *reg_list_size,
                enum target_register_class reg_class)
 {
-       int result = target->type->get_gdb_reg_list(target, reg_list,
+       int result = ERROR_FAIL;
+
+       if (!target_was_examined(target)) {
+               LOG_ERROR("Target not examined yet");
+               goto done;
+       }
+
+       result = target->type->get_gdb_reg_list(target, reg_list,
                        reg_list_size, reg_class);
+
+done:
        if (result != ERROR_OK) {
                *reg_list = NULL;
                *reg_list_size = 0;