1 files changed, 123 insertions, 0 deletions

diff --git a/lib/kernel/debug.c b/lib/kernel/debug.c
new file mode 100644
index 0000000..b12f4f9
--- /dev/null
+++ b/lib/kernel/debug.c
@@ -0,0 +1,123 @@
+#include <debug.h>
+#include <console.h>
+#include <stdarg.h>
+#include <stdbool.h>
+#include <stddef.h>
+#include <stdio.h>
+#include <string.h>
+#include "threads/init.h"
+#include "threads/interrupt.h"
+#include "threads/thread.h"
+#include "threads/switch.h"
+#include "threads/vaddr.h"
+#include "devices/serial.h"
+#include "devices/shutdown.h"
+
+/* Halts the OS, printing the source file name, line number, and
+   function name, plus a user-specific message. */
+void
+debug_panic (const char *file, int line, const char *function,
+             const char *message, ...)
+{
+  static int level;
+  va_list args;
+
+  intr_disable ();
+  console_panic ();
+
+  level++;
+  if (level == 1) 
+    {
+      printf ("Kernel PANIC at %s:%d in %s(): ", file, line, function);
+
+      va_start (args, message);
+      vprintf (message, args);
+      printf ("\n");
+      va_end (args);
+
+      debug_backtrace ();
+    }
+  else if (level == 2)
+    printf ("Kernel PANIC recursion at %s:%d in %s().\n",
+            file, line, function);
+  else 
+    {
+      /* Don't print anything: that's probably why we recursed. */
+    }
+
+  serial_flush ();
+  shutdown ();
+  for (;;);
+}
+
+/* Print call stack of a thread.
+   The thread may be running, ready, or blocked. */
+static void
+print_stacktrace(struct thread *t, void *aux UNUSED)
+{
+  void *retaddr = NULL, **frame = NULL;
+  const char *status = "UNKNOWN";
+
+  switch (t->status) {
+    case THREAD_RUNNING:  
+      status = "RUNNING";
+      break;
+
+    case THREAD_READY:  
+      status = "READY";
+      break;
+
+    case THREAD_BLOCKED:  
+      status = "BLOCKED";
+      break;
+
+    default:
+      break;
+  }
+
+  printf ("Call stack of thread `%s' (status %s):", t->name, status);
+
+  if (t == thread_current()) 
+    {
+      frame = __builtin_frame_address (1);
+      retaddr = __builtin_return_address (0);
+    }
+  else
+    {
+      /* Retrieve the values of the base and instruction pointers
+         as they were saved when this thread called switch_threads. */
+      struct switch_threads_frame * saved_frame;
+
+      saved_frame = (struct switch_threads_frame *)t->stack;
+
+      /* Skip threads if they have been added to the all threads
+         list, but have never been scheduled.
+         We can identify because their `stack' member either points 
+         at the top of their kernel stack page, or the 
+         switch_threads_frame's 'eip' member points at switch_entry.
+         See also threads.c. */
+      if (t->stack == (uint8_t *)t + PGSIZE || saved_frame->eip == switch_entry)
+        {
+          printf (" thread was never scheduled.\n");
+          return;
+        }
+
+      frame = (void **) saved_frame->ebp;
+      retaddr = (void *) saved_frame->eip;
+    }
+
+  printf (" %p", retaddr);
+  for (; (uintptr_t) frame >= 0x1000 && frame[0] != NULL; frame = frame[0])
+    printf (" %p", frame[1]);
+  printf (".\n");
+}
+
+/* Prints call stack of all threads. */
+void
+debug_backtrace_all (void)
+{
+  enum intr_level oldlevel = intr_disable ();
+
+  thread_foreach (print_stacktrace, 0);
+  intr_set_level (oldlevel);
+}