[T106][ZXW-22]7520V3SCV2.01.01.02P42U09_VEC_V0.8_AP_VEC origin source commit

Change-Id: Ic6e05d89ecd62fc34f82b23dcf306c93764aec4b
diff --git a/ap/build/uClibc/libubacktrace/backtrace.c b/ap/build/uClibc/libubacktrace/backtrace.c
new file mode 100644
index 0000000..fdd5981
--- /dev/null
+++ b/ap/build/uClibc/libubacktrace/backtrace.c
@@ -0,0 +1,81 @@
+/*
+ * Perform stack unwinding by using the _Unwind_Backtrace.
+ *
+ * User application that wants to use backtrace needs to be
+ * compiled with -fasynchronous-unwind-tables option and -rdynamic to get full
+ * symbols printed.
+ *
+ * Copyright (C) 2009, 2010 STMicroelectronics Ltd.
+ *
+ * Author(s): Giuseppe Cavallaro <peppe.cavallaro@st.com>
+ * - Initial implementation for glibc
+ *
+ * Author(s): Carmelo Amoroso <carmelo.amoroso@st.com>
+ * - Reworked for uClibc
+ *   - use dlsym/dlopen from libdl
+ *   - rewrite initialisation to not use libc_once
+ *   - make it available in static link too
+ *
+ * Licensed under the LGPL v2.1, see the file COPYING.LIB in this tarball.
+ *
+ */
+
+#include <execinfo.h>
+#include <dlfcn.h>
+#include <stdlib.h>
+#include <unwind.h>
+#include <assert.h>
+#include <stdio.h>
+
+struct trace_arg
+{
+  void **array;
+  int cnt, size;
+};
+
+static _Unwind_Reason_Code (*unwind_backtrace) (_Unwind_Trace_Fn, void *);
+static _Unwind_Ptr (*unwind_getip) (struct _Unwind_Context *);
+
+static void backtrace_init (void)
+{
+	void *handle = dlopen ("libgcc_s.so.1", RTLD_LAZY);
+
+	if (handle == NULL
+		|| ((unwind_backtrace = dlsym (handle, "_Unwind_Backtrace")) == NULL)
+		|| ((unwind_getip = dlsym (handle, "_Unwind_GetIP")) == NULL)) {
+		printf("libgcc_s.so.1 must be installed for backtrace to work\n");
+		abort();
+	}
+}
+
+static _Unwind_Reason_Code
+backtrace_helper (struct _Unwind_Context *ctx, void *a)
+{
+	struct trace_arg *arg = a;
+
+	assert (unwind_getip != NULL);
+
+	/* We are first called with address in the __backtrace function. Skip it. */
+	if (arg->cnt != -1)
+		arg->array[arg->cnt] = (void *) unwind_getip (ctx);
+	if (++arg->cnt == arg->size)
+		return _URC_END_OF_STACK;
+	return _URC_NO_REASON;
+}
+
+/*
+ * Perform stack unwinding by using the _Unwind_Backtrace.
+ *
+ */
+int backtrace (void **array, int size)
+{
+	struct trace_arg arg = { .array = array, .size = size, .cnt = -1 };
+
+	if (unwind_backtrace == NULL)
+		backtrace_init();
+
+	if (size >= 1)
+		unwind_backtrace (backtrace_helper, &arg);
+
+	return arg.cnt != -1 ? arg.cnt : 0;
+}