4 files changed, 29 insertions, 21 deletions

diff --git a/kernel/debug/gdbstub.c b/kernel/debug/gdbstub.c
index a11db956dd62..34872482315e 100644
--- a/kernel/debug/gdbstub.c
+++ b/kernel/debug/gdbstub.c
@@ -42,6 +42,8 @@
 /* Our I/O buffers. */
 static char			remcom_in_buffer[BUFMAX];
 static char			remcom_out_buffer[BUFMAX];
+static int			gdbstub_use_prev_in_buf;
+static int			gdbstub_prev_in_buf_pos;
 
 /* Storage for the registers, in GDB format. */
 static unsigned long		gdb_regs[(NUMREGBYTES +
@@ -58,6 +60,13 @@ static int gdbstub_read_wait(void)
 	int ret = -1;
 	int i;
 
+	if (unlikely(gdbstub_use_prev_in_buf)) {
+		if (gdbstub_prev_in_buf_pos < gdbstub_use_prev_in_buf)
+			return remcom_in_buffer[gdbstub_prev_in_buf_pos++];
+		else
+			gdbstub_use_prev_in_buf = 0;
+	}
+
 	/* poll any additional I/O interfaces that are defined */
 	while (ret < 0)
 		for (i = 0; kdb_poll_funcs[i] != NULL; i++) {
@@ -109,7 +118,6 @@ static void get_packet(char *buffer)
 			buffer[count] = ch;
 			count = count + 1;
 		}
-		buffer[count] = 0;
 
 		if (ch == '#') {
 			xmitcsum = hex_to_bin(gdbstub_read_wait()) << 4;
@@ -124,6 +132,7 @@ static void get_packet(char *buffer)
 			if (dbg_io_ops->flush)
 				dbg_io_ops->flush();
 		}
+		buffer[count] = 0;
 	} while (checksum != xmitcsum);
 }
 
@@ -1082,12 +1091,11 @@ int gdbstub_state(struct kgdb_state *ks, char *cmd)
 	case 'c':
 		strcpy(remcom_in_buffer, cmd);
 		return 0;
-	case '?':
-		gdb_cmd_status(ks);
-		break;
-	case '\0':
-		strcpy(remcom_out_buffer, "");
-		break;
+	case '$':
+		strcpy(remcom_in_buffer, cmd);
+		gdbstub_use_prev_in_buf = strlen(remcom_in_buffer);
+		gdbstub_prev_in_buf_pos = 0;
+		return 0;
 	}
 	dbg_io_ops->write_char('+');
 	put_packet(remcom_out_buffer);
diff --git a/kernel/debug/kdb/kdb_debugger.c b/kernel/debug/kdb/kdb_debugger.c
index dd0b1b7dd02c..fe422d275782 100644
--- a/kernel/debug/kdb/kdb_debugger.c
+++ b/kernel/debug/kdb/kdb_debugger.c
@@ -30,6 +30,8 @@ EXPORT_SYMBOL_GPL(kdb_poll_funcs);
 int kdb_poll_idx = 1;
 EXPORT_SYMBOL_GPL(kdb_poll_idx);
 
+static struct kgdb_state *kdb_ks;
+
 int kdb_stub(struct kgdb_state *ks)
 {
 	int error = 0;
@@ -39,6 +41,7 @@ int kdb_stub(struct kgdb_state *ks)
 	kdb_dbtrap_t db_result = KDB_DB_NOBPT;
 	int i;
 
+	kdb_ks = ks;
 	if (KDB_STATE(REENTRY)) {
 		reason = KDB_REASON_SWITCH;
 		KDB_STATE_CLEAR(REENTRY);
@@ -124,16 +127,6 @@ int kdb_stub(struct kgdb_state *ks)
 	kdbnearsym_cleanup();
 	if (error == KDB_CMD_KGDB) {
 		if (KDB_STATE(DOING_KGDB) || KDB_STATE(DOING_KGDB2)) {
-	/*
-	 * This inteface glue which allows kdb to transition in into
-	 * the gdb stub.  In order to do this the '?' or '' gdb serial
-	 * packet response is processed here.  And then control is
-	 * passed to the gdbstub.
-	 */
-			if (KDB_STATE(DOING_KGDB))
-				gdbstub_state(ks, "?");
-			else
-				gdbstub_state(ks, "");
 			KDB_STATE_CLEAR(DOING_KGDB);
 			KDB_STATE_CLEAR(DOING_KGDB2);
 		}
@@ -166,3 +159,7 @@ int kdb_stub(struct kgdb_state *ks)
 	return kgdb_info[ks->cpu].ret_state;
 }
 
+void kdb_gdb_state_pass(char *buf)
+{
+	gdbstub_state(kdb_ks, buf);
+}
diff --git a/kernel/debug/kdb/kdb_io.c b/kernel/debug/kdb/kdb_io.c
index 96fdaac46a80..bd233264b29f 100644
--- a/kernel/debug/kdb/kdb_io.c
+++ b/kernel/debug/kdb/kdb_io.c
@@ -35,8 +35,8 @@ static void kgdb_transition_check(char *buffer)
 {
 	int slen = strlen(buffer);
 	if (strncmp(buffer, "$?#3f", slen) != 0 &&
-	    strncmp(buffer, "$qSupported#37", slen) != 0 &&
-	    strncmp(buffer, "+$qSupported#37", slen) != 0) {
+	    strncmp(buffer, "$qSupported", slen) != 0 &&
+	    strncmp(buffer, "+$qSupported", slen) != 0) {
 		KDB_STATE_SET(KGDB_TRANS);
 		kdb_printf("%s", buffer);
 	}
@@ -390,12 +390,14 @@ poll_again:
 			/* Special escape to kgdb */
 			if (lastchar - buffer >= 5 &&
 			    strcmp(lastchar - 5, "$?#3f") == 0) {
+				kdb_gdb_state_pass(lastchar - 5);
 				strcpy(buffer, "kgdb");
 				KDB_STATE_SET(DOING_KGDB);
 				return buffer;
 			}
-			if (lastchar - buffer >= 14 &&
-			    strcmp(lastchar - 14, "$qSupported#37") == 0) {
+			if (lastchar - buffer >= 11 &&
+			    strcmp(lastchar - 11, "$qSupported") == 0) {
+				kdb_gdb_state_pass(lastchar - 11);
 				strcpy(buffer, "kgdb");
 				KDB_STATE_SET(DOING_KGDB2);
 				return buffer;
diff --git a/kernel/debug/kdb/kdb_private.h b/kernel/debug/kdb/kdb_private.h
index 35d69ed1dfb5..03d332e63442 100644
--- a/kernel/debug/kdb/kdb_private.h
+++ b/kernel/debug/kdb/kdb_private.h
@@ -218,6 +218,7 @@ extern void kdb_print_nameval(const char *name, unsigned long val);
 extern void kdb_send_sig_info(struct task_struct *p, struct siginfo *info);
 extern void kdb_meminfo_proc_show(void);
 extern char *kdb_getstr(char *, size_t, char *);
+extern void kdb_gdb_state_pass(char *buf);
 
 /* Defines for kdb_symbol_print */
 #define KDB_SP_SPACEB	0x0001		/* Space before string */