[PATCH 27/37] debug_core,kdb: Allow the debug core to process a recursive debug entry

[Jason Wessel <jason.wessel@xxxxxxxxxxxxx>]

This allows kdb to debug a crash with in the kms code with a
single level recursive re-entry.

Signed-off-by: Jason Wessel <jason.wessel@xxxxxxxxxxxxx>
---
 kernel/debug/debug_core.c |    7 +++++++
 1 files changed, 7 insertions(+), 0 deletions(-)

diff --git a/kernel/debug/debug_core.c b/kernel/debug/debug_core.c
index e44e693..e6c6f8a 100644
--- a/kernel/debug/debug_core.c
+++ b/kernel/debug/debug_core.c
@@ -443,6 +443,10 @@ static int kgdb_reenter_check(struct kgdb_state *ks)
        }
 
        printk(KERN_CRIT "KGDB: re-enter exception: ALL breakpoints killed\n");
+#ifdef CONFIG_KGDB_KDB
+       /* Allow kdb to debug itself one level */
+       return 0;
+#endif
        dump_stack();
        panic("Recursive entry to debugger");
 
@@ -487,6 +491,9 @@ acquirelock:
        smp_wmb();
        atomic_set(&cpu_in_kgdb[cpu], 1);
 
+       if (exception_level == 1)
+               goto cpu_master_loop;
+
        /*
         * CPU will loop if it is a slave or request to become a kgdb
         * master cpu and acquire the kgdb_active lock:
-- 
1.6.4.rc1