arch: x86: intel64: make perf stack thrace func

Implement stack trace function for x86_64 arch, that get required
thread register values and unwind stack with it.

Originally-by: Yonatan Goldschmidt <[email protected]>
Signed-off-by: Mikhail Kushnerov <[email protected]>

Author: Mikhail Kushnerov

arch/x86/core/intel64.cmake

@@ -20,3 +20,4 @@ zephyr_library_sources_ifdef(CONFIG_IRQ_OFFLOAD		intel64/irq_offload.c)
 zephyr_library_sources_ifdef(CONFIG_USERSPACE	intel64/userspace.S)
 zephyr_library_sources_ifdef(CONFIG_THREAD_LOCAL_STORAGE	intel64/tls.c)
 zephyr_library_sources_ifdef(CONFIG_DEBUG_COREDUMP	intel64/coredump.c)
+zephyr_library_sources_ifdef(CONFIG_PROFILING_PERF	intel64/perf.c)

arch/x86/core/intel64/perf.c

@@ -0,0 +1,67 @@
+/*
+ *  Copyright (c) 2023 KNS Group LLC (YADRO)
+ *  Copyright (c) 2020 Yonatan Goldschmidt <[email protected]>
+ *
+ *  SPDX-License-Identifier: Apache-2.0
+ */
+
+#include <zephyr/kernel.h>
+
+static bool valid_stack(uintptr_t addr, k_tid_t current)
+{
+	return current->stack_info.start <= addr &&
+		addr < current->stack_info.start + current->stack_info.size;
+}
+
+/*
+ * This function use frame pointers to unwind stack and get trace of return addresses.
+ * Return addresses are translated in corresponding function's names using .elf file.
+ * So we get function call trace
+ */
+size_t arch_perf_current_stack_trace(uintptr_t *buf, size_t size)
+{
+	if (size < 1U)
+		return 0;
+
+	size_t idx = 0;
+
+	/*
+	 * In x86_64 (arch/x86/core/intel64/locore.S) %rip and %rbp
+	 * are always saved in _current->callee_saved before calling
+	 * handler function if interrupt is not nested
+	 *
+	 * %rip points the location where interrupt was occurred
+	 */
+	buf[idx++] = (uintptr_t)_current->callee_saved.rip;
+	void **fp = (void **)_current->callee_saved.rbp;
+
+	/*
+	 * %rbp is frame pointer.
+	 *
+	 * stack frame in memory:
+	 * (addresses growth up)
+	 *  ....
+	 *  ra
+	 *  %rbp (next) <- %rbp (curr)
+	 *  ....
+	 */
+	while (valid_stack((uintptr_t)fp, _current)) {
+		if (idx >= size)
+			return 0;
+
+		buf[idx++] = (uintptr_t)fp[1];
+		void **new_fp = (void **)fp[0];
+
+		/*
+		 * anti-infinity-loop if
+		 * new_fp can't be smaller than fp, cause the stack is growing down
+		 * and trace moves deeper into the stack
+		 */
+		if (new_fp <= fp) {
+			break;
+		}
+		fp = new_fp;
+	}
+
+	return idx;
+}