3 files changed, 14 insertions, 3 deletions

diff --git a/kernel/debug/debug_core.c b/kernel/debug/debug_core.c
index 1adf62b39b96..acd749736822 100644
--- a/kernel/debug/debug_core.c
+++ b/kernel/debug/debug_core.c
@@ -471,6 +471,7 @@ static int kgdb_cpu_enter(struct kgdb_state *ks, struct pt_regs *regs,
         int cpu;
         int trace_on = 0;
         int online_cpus = num_online_cpus();
+        u64 time_left;
 
         kgdb_info[ks->cpu].enter_kgdb++;
         kgdb_info[ks->cpu].exception_state |= exception_state;
@@ -595,9 +596,13 @@ return_normal:
         /*
          * Wait for the other CPUs to be notified and be waiting for us:
          */
-        while (kgdb_do_roundup && (atomic_read(&masters_in_kgdb) +
-                                atomic_read(&slaves_in_kgdb)) != online_cpus)
+        time_left = loops_per_jiffy * HZ;
+        while (kgdb_do_roundup && --time_left &&
+               (atomic_read(&masters_in_kgdb) + atomic_read(&slaves_in_kgdb)) !=
+                   online_cpus)
                 cpu_relax();
+        if (!time_left)
+                pr_crit("KGDB: Timed out waiting for secondary CPUs.\n");
 
         /*
          * At this point the primary processor is completely
diff --git a/kernel/debug/kdb/kdb_debugger.c b/kernel/debug/kdb/kdb_debugger.c
index 8859ca34dcfe..15e1a7af5dd0 100644
--- a/kernel/debug/kdb/kdb_debugger.c
+++ b/kernel/debug/kdb/kdb_debugger.c
@@ -129,6 +129,10 @@ int kdb_stub(struct kgdb_state *ks)
                 ks->pass_exception = 1;
                 KDB_FLAG_SET(CATASTROPHIC);
         }
+        /* set CATASTROPHIC if the system contains unresponsive processors */
+        for_each_online_cpu(i)
+                if (!kgdb_info[i].enter_kgdb)
+                        KDB_FLAG_SET(CATASTROPHIC);
         if (KDB_STATE(SSBPT) && reason == KDB_REASON_SSTEP) {
                 KDB_STATE_CLEAR(SSBPT);
                 KDB_STATE_CLEAR(DOING_SS);
diff --git a/kernel/debug/kdb/kdb_main.c b/kernel/debug/kdb/kdb_main.c
index 8d84979cbe05..f191bddf64b8 100644
--- a/kernel/debug/kdb/kdb_main.c
+++ b/kernel/debug/kdb/kdb_main.c
@@ -2201,6 +2201,8 @@ static void kdb_cpu_status(void)
         for (start_cpu = -1, i = 0; i < NR_CPUS; i++) {
                 if (!cpu_online(i)) {
                         state = 'F';    /* cpu is offline */
+                } else if (!kgdb_info[i].enter_kgdb) {
+                        state = 'D';    /* cpu is online but unresponsive */
                 } else {
                         state = ' ';    /* cpu is responding to kdb */
                         if (kdb_task_state_char(KDB_TSK(i)) == 'I')
@@ -2254,7 +2256,7 @@ static int kdb_cpu(int argc, const char **argv)
         /*
          * Validate cpunum
          */
-        if ((cpunum > NR_CPUS) || !cpu_online(cpunum))
+        if ((cpunum > NR_CPUS) || !kgdb_info[cpunum].enter_kgdb)
                 return KDB_BADCPUNUM;
 
         dbg_switch_cpu = cpunum;