kgdb: gdb "monitor" -> kdb passthrough

One of the driving forces behind integrating another front end (kdb)
to the debug core is to allow front end commands to be accessible via
gdb's monitor command.  It is true that you could write gdb macros to
get certain data, but you may want to just use gdb to access the
commands that are available in the kdb front end.

This patch implements the Rcmd gdb stub packet.  In gdb you access
this with the "monitor" command.  For instance you could type "monitor
help", "monitor lsmod" or "monitor ps A" etc...

There is no error checking or command restrictions on what you can and
cannot access at this point.  Doing something like trying to set
breakpoints with the monitor command is going to cause nothing but
problems.  Perhaps in the future only the commands that are actually
known to work with the gdb monitor command will be available.

Signed-off-by: Jason Wessel <jason.wessel@windriver.com>

diff --git a/kernel/debug/debug_core.c b/kernel/debug/debug_core.c
index 1d71df66f3fa7c9027e39742e4fc0680acdde1b6..1aed37b4c564c843fa2d92a145255de45188200f 100644 (file)
--- a/kernel/debug/debug_core.c
+++ b/kernel/debug/debug_core.c
@@ -82,7 +82,7 @@ static int kgdb_use_con;
 int dbg_switch_cpu;
 
 /* Use kdb or gdbserver mode */
-static int dbg_kdb_mode = 1;
+int dbg_kdb_mode = 1;
 
 static int __init opt_kgdb_con(char *str)
 {

diff --git a/kernel/debug/debug_core.h b/kernel/debug/debug_core.h
index 44cf3de8cf9e515f6524c012b25d166dc48ac470..c5d753d80f6764869512a4884dc717a14c1b1e66 100644 (file)
--- a/kernel/debug/debug_core.h
+++ b/kernel/debug/debug_core.h
@@ -66,9 +66,11 @@ extern void gdbstub_msg_write(const char *s, int len);
 
 /* gdbstub functions used for kdb <-> gdbstub transition */
 extern int gdbstub_state(struct kgdb_state *ks, char *cmd);
+extern int dbg_kdb_mode;
 
 #ifdef CONFIG_KGDB_KDB
 extern int kdb_stub(struct kgdb_state *ks);
+extern int kdb_parse(const char *cmdstr);
 #else /* ! CONFIG_KGDB_KDB */
 static inline int kdb_stub(struct kgdb_state *ks)
 {

diff --git a/kernel/debug/gdbstub.c b/kernel/debug/gdbstub.c
index 3c000490a7dd1938cb20a3f410ab31223bbf8c18..4b17b32695259060260f9748d2c51490397c4888 100644 (file)
--- a/kernel/debug/gdbstub.c
+++ b/kernel/debug/gdbstub.c
@@ -201,6 +201,9 @@ void gdbstub_msg_write(const char *s, int len)
        int wcount;
        int i;
 
+       if (len == 0)
+               len = strlen(s);
+
        /* 'O'utput */
        gdbmsgbuf[0] = 'O';
 
@@ -685,6 +688,25 @@ static void gdb_cmd_query(struct kgdb_state *ks)
                        kgdb_mem2hex(tmpstr, remcom_out_buffer, strlen(tmpstr));
                }
                break;
+#ifdef CONFIG_KGDB_KDB
+       case 'R':
+               if (strncmp(remcom_in_buffer, "qRcmd,", 6) == 0) {
+                       int len = strlen(remcom_in_buffer + 6);
+
+                       if ((len % 2) != 0) {
+                               strcpy(remcom_out_buffer, "E01");
+                               break;
+                       }
+                       kgdb_hex2mem(remcom_in_buffer + 6,
+                                    remcom_out_buffer, len);
+                       len = len / 2;
+                       remcom_out_buffer[len++] = 0;
+
+                       kdb_parse(remcom_out_buffer);
+                       strcpy(remcom_out_buffer, "OK");
+               }
+               break;
+#endif
        }
 }
 

diff --git a/kernel/debug/kdb/kdb_io.c b/kernel/debug/kdb/kdb_io.c
index 9e3cec7a925c7bfced9ace00b6f90ed551df6d3b..8339b291e8bc23c3acbc434da51df87ce8c796db 100644 (file)
--- a/kernel/debug/kdb/kdb_io.c
+++ b/kernel/debug/kdb/kdb_io.c
@@ -21,6 +21,7 @@
 #include <linux/smp.h>
 #include <linux/nmi.h>
 #include <linux/delay.h>
+#include <linux/kgdb.h>
 #include <linux/kdb.h>
 #include <linux/kallsyms.h>
 #include "kdb_private.h"
@@ -669,10 +670,14 @@ kdb_printit:
         * Write to all consoles.
         */
        retlen = strlen(kdb_buffer);
-       while (c) {
-               c->write(c, kdb_buffer, retlen);
-               touch_nmi_watchdog();
-               c = c->next;
+       if (!dbg_kdb_mode && kgdb_connected) {
+               gdbstub_msg_write(kdb_buffer, retlen);
+       } else {
+               while (c) {
+                       c->write(c, kdb_buffer, retlen);
+                       touch_nmi_watchdog();
+                       c = c->next;
+               }
        }
        if (logging) {
                saved_loglevel = console_loglevel;

diff --git a/kernel/debug/kdb/kdb_private.h b/kernel/debug/kdb/kdb_private.h
index 69ed2eff3feaa6c988ee9d42be0064e29845f57b..97d3ba69775df3b66120f0e7579fc8fba0d896da 100644 (file)
--- a/kernel/debug/kdb/kdb_private.h
+++ b/kernel/debug/kdb/kdb_private.h
@@ -254,7 +254,6 @@ extern unsigned long kdb_task_state(const struct task_struct *p,
                                    unsigned long mask);
 extern void kdb_ps_suppressed(void);
 extern void kdb_ps1(const struct task_struct *p);
-extern int kdb_parse(const char *cmdstr);
 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);