1 files changed, 94 insertions, 0 deletions
diff --git a/libipt/src/pt_retstack.c b/libipt/src/pt_retstack.c
new file mode 100644
index 0000000000000..34733f25e8699
--- /dev/null
+++ b/libipt/src/pt_retstack.c
@@ -0,0 +1,94 @@
+/*
+ * Copyright (c) 2013-2019, Intel Corporation
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are met:
+ *
+ *  * Redistributions of source code must retain the above copyright notice,
+ *    this list of conditions and the following disclaimer.
+ *  * Redistributions in binary form must reproduce the above copyright notice,
+ *    this list of conditions and the following disclaimer in the documentation
+ *    and/or other materials provided with the distribution.
+ *  * Neither the name of Intel Corporation nor the names of its contributors
+ *    may be used to endorse or promote products derived from this software
+ *    without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
+ * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
+ * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
+ * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
+ * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
+ * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
+ * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
+ * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+ * POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#include "pt_retstack.h"
+
+#include "intel-pt.h"
+
+
+void pt_retstack_init(struct pt_retstack *retstack)
+{
+	if (!retstack)
+		return;
+
+	retstack->top = 0;
+	retstack->bottom = 0;
+}
+
+int pt_retstack_is_empty(const struct pt_retstack *retstack)
+{
+	if (!retstack)
+		return -pte_invalid;
+
+	return (retstack->top == retstack->bottom ? 1 : 0);
+}
+
+int pt_retstack_pop(struct pt_retstack *retstack, uint64_t *ip)
+{
+	uint8_t top;
+
+	if (!retstack)
+		return -pte_invalid;
+
+	top = retstack->top;
+
+	if (top == retstack->bottom)
+		return -pte_retstack_empty;
+
+	top = (!top ? pt_retstack_size : top - 1);
+
+	retstack->top = top;
+
+	if (ip)
+		*ip = retstack->stack[top];
+
+	return 0;
+}
+
+int pt_retstack_push(struct pt_retstack *retstack, uint64_t ip)
+{
+	uint8_t top, bottom;
+
+	if (!retstack)
+		return -pte_invalid;
+
+	top = retstack->top;
+	bottom = retstack->bottom;
+
+	retstack->stack[top] = ip;
+
+	top = (top == pt_retstack_size ? 0 : top + 1);
+
+	if (bottom == top)
+		bottom = (bottom == pt_retstack_size ? 0 : bottom + 1);
+
+	retstack->top = top;
+	retstack->bottom = bottom;
+
+	return 0;
+}