1 files changed, 12 insertions, 2 deletions

diff --git a/kernel/printk.c b/kernel/printk.c
index 1baace7d867..cbebc142be1 100644
--- a/kernel/printk.c
+++ b/kernel/printk.c
@@ -74,6 +74,13 @@ int console_printk[4] = {
 };
 
 /*
+ * divert printk() messages when there is a LITMUS^RT debug listener
+ */
+#include <litmus/litmus.h>
+int trace_override = 0;
+int trace_recurse  = 0;
+
+/*
  * Low level drivers may need that to know if they can schedule in
  * their unblank() callback or not. So let's export it.
  */
@@ -926,6 +933,9 @@ asmlinkage int vprintk(const char *fmt, va_list args)
         /* Emit the output into the temporary buffer */
         printed_len += vscnprintf(printk_buf + printed_len,
                                   sizeof(printk_buf) - printed_len, fmt, args);
+        /* if LITMUS^RT tracer is active divert printk() msgs */
+        if (trace_override && !trace_recurse)
+                TRACE("%s", printk_buf);
 
 #ifdef  CONFIG_DEBUG_LL
         printascii(printk_buf);
@@ -1006,7 +1016,7 @@ asmlinkage int vprintk(const char *fmt, va_list args)
          * Try to acquire and then immediately release the
          * console semaphore. The release will do all the
          * actual magic (print out buffers, wake up klogd,
-         * etc). 
+         * etc).
          *
          * The console_trylock_for_printk() function
          * will release 'logbuf_lock' regardless of whether it
@@ -1278,7 +1288,7 @@ int printk_needs_cpu(int cpu)
 
 void wake_up_klogd(void)
 {
-        if (waitqueue_active(&log_wait))
+        if (!trace_override && waitqueue_active(&log_wait))
                 this_cpu_write(printk_pending, 1);
 }