repair gdbstub to match the gdbserial protocol specification

The gdbserial protocol handler should return an empty packet instead
of an error string when ever it responds to a command it does not
implement.

The problem cases come from a debugger client sending
qTBuffer, qTStatus, qSearch, qSupported.

The incorrect response from the gdbstub leads the debugger clients to
not function correctly.  Recent versions of gdb will not detach correctly as a result of this behavior.

Signed-off-by: Jason Wessel <jason.wessel@windriver.com>
Signed-off-by: Dongdong Deng <dongdong.deng@windriver.com>

1 files changed, 3 insertions, 6 deletions

diff --git a/kernel/debug/gdbstub.c b/kernel/debug/gdbstub.c
index 4b17b326952..e8fd6868682 100644
--- a/kernel/debug/gdbstub.c
+++ b/kernel/debug/gdbstub.c
@@ -621,10 +621,8 @@ static void gdb_cmd_query(struct kgdb_state *ks)
         switch (remcom_in_buffer[1]) {
         case 's':
         case 'f':
-                if (memcmp(remcom_in_buffer + 2, "ThreadInfo", 10)) {
-                        error_packet(remcom_out_buffer, -EINVAL);
+                if (memcmp(remcom_in_buffer + 2, "ThreadInfo", 10))
                         break;
-                }
 
                 i = 0;
                 remcom_out_buffer[0] = 'm';
@@ -665,10 +663,9 @@ static void gdb_cmd_query(struct kgdb_state *ks)
                 pack_threadid(remcom_out_buffer + 2, thref);
                 break;
         case 'T':
-                if (memcmp(remcom_in_buffer + 1, "ThreadExtraInfo,", 16)) {
-                        error_packet(remcom_out_buffer, -EINVAL);
+                if (memcmp(remcom_in_buffer + 1, "ThreadExtraInfo,", 16))
                         break;
-                }
+
                 ks->threadid = 0;
                 ptr = remcom_in_buffer + 17;
                 kgdb_hex2long(&ptr, &ks->threadid);