kgdb: timeout if secondary CPUs ignore the roundup

[firefly-linux-kernel-4.4.55.git] / kernel / debug / debug_core.c

diff --git a/kernel/debug/debug_core.c b/kernel/debug/debug_core.c
index 1adf62b39b96b496e56ca8484c6939429981277c..acd7497368223534fb2cbf8aabbccb5f30920093 100644 (file)
--- 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