1 files changed, 41 insertions, 0 deletions

diff --git a/kernel/debug/debug_core.c b/kernel/debug/debug_core.c
index f3cadda45f07..10db2833a423 100644
--- a/kernel/debug/debug_core.c
+++ b/kernel/debug/debug_core.c
@@ -55,6 +55,7 @@
 #include <linux/mm.h>
 #include <linux/vmacache.h>
 #include <linux/rcupdate.h>
+#include <linux/irq.h>
 
 #include <asm/cacheflush.h>
 #include <asm/byteorder.h>
@@ -220,6 +221,46 @@ int __weak kgdb_skipexception(int exception, struct pt_regs *regs)
         return 0;
 }
 
+#ifdef CONFIG_SMP
+
+/*
+ * Default (weak) implementation for kgdb_roundup_cpus
+ */
+
+static DEFINE_PER_CPU(call_single_data_t, kgdb_roundup_csd);
+
+void __weak kgdb_call_nmi_hook(void *ignored)
+{
+        /*
+         * NOTE: get_irq_regs() is supposed to get the registers from
+         * before the IPI interrupt happened and so is supposed to
+         * show where the processor was.  In some situations it's
+         * possible we might be called without an IPI, so it might be
+         * safer to figure out how to make kgdb_breakpoint() work
+         * properly here.
+         */
+        kgdb_nmicallback(raw_smp_processor_id(), get_irq_regs());
+}
+
+void __weak kgdb_roundup_cpus(void)
+{
+        call_single_data_t *csd;
+        int this_cpu = raw_smp_processor_id();
+        int cpu;
+
+        for_each_online_cpu(cpu) {
+                /* No need to roundup ourselves */
+                if (cpu == this_cpu)
+                        continue;
+
+                csd = &per_cpu(kgdb_roundup_csd, cpu);
+                csd->func = kgdb_call_nmi_hook;
+                smp_call_function_single_async(cpu, csd);
+        }
+}
+
+#endif
+
 /*
  * Some architectures need cache flushes when we set/clear a
  * breakpoint: