print_trace

testcase/userstack.c

@@ -1,15 +1,46 @@
 #include <stdio.h>
+#include <libunwind.h>
 #include <unistd.h>
 
 void customFunction1(int n);
 void customFunction2(int n);
 void customFunction3(int n);
 
+// Call this function to get a backtrace.
+void backtrace() {
+  unw_cursor_t cursor;
+  unw_context_t context;
+
+  // Initialize cursor to current frame for local unwinding.
+  unw_getcontext(&context);
+  unw_init_local(&cursor, &context);
+
+  // Unwind frames one by one, going up the frame stack.
+  while (unw_step(&cursor) > 0) {
+    unw_word_t offset, pc;
+    unw_get_reg(&cursor, UNW_REG_IP, &pc);
+    if (pc == 0) {
+      break;
+    }
+    printf("0x%lx:", pc);
+
+    char sym[256];
+    if (unw_get_proc_name(&cursor, sym, sizeof(sym), &offset) == 0) {
+      printf(" (%s+0x%lx)\n", sym, offset);
+    } else {
+      printf(" -- error: unable to obtain symbol name for this frame\n");
+    }
+  }
+}
+
 void customFunction1(int n) {
     if(n <= 0) {
         printf("End of recursion\n");
+        // output backtrace
+        printf("pid: %d\n", getpid());
+        backtrace();
         while (1) {
-            // sleep(1);
+            sleep(1);
         } // never return, keep stack
         return;
     } else {