1 files changed, 22 insertions, 0 deletions

diff --git a/arch/x86/kernel/cpu/mcheck/mce.c b/arch/x86/kernel/cpu/mcheck/mce.c
index 121781627858..421020f1d7db 100644
--- a/arch/x86/kernel/cpu/mcheck/mce.c
+++ b/arch/x86/kernel/cpu/mcheck/mce.c
@@ -196,10 +196,32 @@ static void print_mce(struct mce *m)
                "and contact your hardware vendor\n");
 }
 
+#define PANIC_TIMEOUT 5 /* 5 seconds */
+
+static atomic_t mce_paniced;
+
+/* Panic in progress. Enable interrupts and wait for final IPI */
+static void wait_for_panic(void)
+{
+        long timeout = PANIC_TIMEOUT*USEC_PER_SEC;
+        preempt_disable();
+        local_irq_enable();
+        while (timeout-- > 0)
+                udelay(1);
+        panic("Panicing machine check CPU died");
+}
+
 static void mce_panic(char *msg, struct mce *final, char *exp)
 {
         int i;
 
+        /*
+         * Make sure only one CPU runs in machine check panic
+         */
+        if (atomic_add_return(1, &mce_paniced) > 1)
+                wait_for_panic();
+        barrier();
+
         bust_spinlocks(1);
         console_verbose();
         /* First print corrected ones that are still unlogged */