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 */