4 files changed, 42 insertions, 9 deletions

diff --git a/arch/x86/kernel/kgdb.c b/arch/x86/kernel/kgdb.c
index 95b89d4cb8f1..2b71ec41869f 100644
--- a/arch/x86/kernel/kgdb.c
+++ b/arch/x86/kernel/kgdb.c
@@ -596,14 +596,15 @@ static struct notifier_block kgdb_notifier = {
  */
 int kgdb_arch_init(void)
 {
+        return register_die_notifier(&kgdb_notifier);
+}
+
+void kgdb_arch_late(void)
+{
         int i, cpu;
-        int ret;
         struct perf_event_attr attr;
         struct perf_event **pevent;
 
-        ret = register_die_notifier(&kgdb_notifier);
-        if (ret != 0)
-                return ret;
         /*
          * Pre-allocate the hw breakpoint structions in the non-atomic
          * portion of kgdb because this operation requires mutexs to
@@ -615,12 +616,15 @@ int kgdb_arch_init(void)
         attr.bp_type = HW_BREAKPOINT_W;
         attr.disabled = 1;
         for (i = 0; i < 4; i++) {
+                if (breakinfo[i].pev)
+                        continue;
                 breakinfo[i].pev = register_wide_hw_breakpoint(&attr, NULL);
                 if (IS_ERR(breakinfo[i].pev)) {
-                        printk(KERN_ERR "kgdb: Could not allocate hw breakpoints\n");
+                        printk(KERN_ERR "kgdb: Could not allocate hw"
+                               "breakpoints\nDisabling the kernel debugger\n");
                         breakinfo[i].pev = NULL;
                         kgdb_arch_exit();
-                        return -1;
+                        return;
                 }
                 for_each_online_cpu(cpu) {
                         pevent = per_cpu_ptr(breakinfo[i].pev, cpu);
@@ -631,7 +635,6 @@ int kgdb_arch_init(void)
                         }
                 }
         }
-        return ret;
 }
 
 /**
diff --git a/include/linux/kgdb.h b/include/linux/kgdb.h
index 6c784ab6856a..9340f34d1bb5 100644
--- a/include/linux/kgdb.h
+++ b/include/linux/kgdb.h
@@ -208,6 +208,17 @@ extern int kgdb_arch_set_breakpoint(unsigned long addr, char *saved_instr);
 extern int kgdb_arch_remove_breakpoint(unsigned long addr, char *bundle);
 
 /**
+ *      kgdb_arch_late - Perform any architecture specific initalization.
+ *
+ *      This function will handle the late initalization of any
+ *      architecture specific callbacks.  This is an optional function for
+ *      handling things like late initialization of hw breakpoints.  The
+ *      default implementation does nothing.
+ */
+extern void kgdb_arch_late(void);
+
+
+/**
  * struct kgdb_arch - Describe architecture specific values.
  * @gdb_bpt_instr: The instruction to trigger a breakpoint.
  * @flags: Flags for the breakpoint, currently just %KGDB_HW_BREAKPOINT.
@@ -285,7 +296,10 @@ extern int			kgdb_single_step;
 extern atomic_t                 kgdb_active;
 #define in_dbg_master() \
         (raw_smp_processor_id() == atomic_read(&kgdb_active))
+extern bool dbg_is_early;
+extern void __init dbg_late_init(void);
 #else /* ! CONFIG_KGDB */
 #define in_dbg_master() (0)
+#define dbg_late_init()
 #endif /* ! CONFIG_KGDB */
 #endif /* _KGDB_H_ */
diff --git a/init/main.c b/init/main.c
index 372771333d98..22881b5e95e3 100644
--- a/init/main.c
+++ b/init/main.c
@@ -62,7 +62,7 @@
 #include <linux/sched.h>
 #include <linux/signal.h>
 #include <linux/idr.h>
-#include <linux/kdb.h>
+#include <linux/kgdb.h>
 #include <linux/ftrace.h>
 #include <linux/async.h>
 #include <linux/kmemcheck.h>
@@ -676,7 +676,7 @@ asmlinkage void __init start_kernel(void)
         buffer_init();
         key_init();
         security_init();
-        kdb_init(KDB_INIT_FULL);
+        dbg_late_init();
         vfs_caches_init(totalram_pages);
         signals_init();
         /* rootfs populating might need page-writeback */
diff --git a/kernel/debug/debug_core.c b/kernel/debug/debug_core.c
index 64b5588c9638..5cb7cd1de10c 100644
--- a/kernel/debug/debug_core.c
+++ b/kernel/debug/debug_core.c
@@ -78,6 +78,8 @@ static DEFINE_SPINLOCK(kgdb_registration_lock);
 static int kgdb_con_registered;
 /* determine if kgdb console output should be used */
 static int kgdb_use_con;
+/* Flag for alternate operations for early debugging */
+bool dbg_is_early = true;
 /* Next cpu to become the master debug core */
 int dbg_switch_cpu;
 
@@ -777,11 +779,25 @@ static struct notifier_block kgdb_panic_event_nb = {
        .priority        = INT_MAX,
 };
 
+void __weak kgdb_arch_late(void)
+{
+}
+
+void __init dbg_late_init(void)
+{
+        dbg_is_early = false;
+        if (kgdb_io_module_registered)
+                kgdb_arch_late();
+        kdb_init(KDB_INIT_FULL);
+}
+
 static void kgdb_register_callbacks(void)
 {
         if (!kgdb_io_module_registered) {
                 kgdb_io_module_registered = 1;
                 kgdb_arch_init();
+                if (!dbg_is_early)
+                        kgdb_arch_late();
                 atomic_notifier_chain_register(&panic_notifier_list,
                                                &kgdb_panic_event_nb);
 #ifdef CONFIG_MAGIC_SYSRQ