Merging upstream version 6.1.82.

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

2 files changed, 50 insertions, 0 deletions

diff --git a/arch/riscv/kernel/Makefile b/arch/riscv/kernel/Makefile
index ab333cb79..4c0805d26 100644
--- a/arch/riscv/kernel/Makefile
+++ b/arch/riscv/kernel/Makefile
@@ -7,6 +7,7 @@ ifdef CONFIG_FTRACE
 CFLAGS_REMOVE_ftrace.o	= $(CC_FLAGS_FTRACE)
 CFLAGS_REMOVE_patch.o	= $(CC_FLAGS_FTRACE)
 CFLAGS_REMOVE_sbi.o	= $(CC_FLAGS_FTRACE)
+CFLAGS_REMOVE_return_address.o	= $(CC_FLAGS_FTRACE)
 endif
 CFLAGS_syscall_table.o	+= $(call cc-option,-Wno-override-init,)
 CFLAGS_compat_syscall_table.o += $(call cc-option,-Wno-override-init,)
@@ -41,6 +42,7 @@ obj-y	+= irq.o
 obj-y	+= process.o
 obj-y	+= ptrace.o
 obj-y	+= reset.o
+obj-y	+= return_address.o
 obj-y	+= setup.o
 obj-y	+= signal.o
 obj-y	+= syscall_table.o
diff --git a/arch/riscv/kernel/return_address.c b/arch/riscv/kernel/return_address.c
new file mode 100644
index 000000000..c8115ec8f
--- /dev/null
+++ b/arch/riscv/kernel/return_address.c
@@ -0,0 +1,48 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * This code come from arch/arm64/kernel/return_address.c
+ *
+ * Copyright (C) 2023 SiFive.
+ */
+
+#include <linux/export.h>
+#include <linux/kprobes.h>
+#include <linux/stacktrace.h>
+
+struct return_address_data {
+	unsigned int level;
+	void *addr;
+};
+
+static bool save_return_addr(void *d, unsigned long pc)
+{
+	struct return_address_data *data = d;
+
+	if (!data->level) {
+		data->addr = (void *)pc;
+		return false;
+	}
+
+	--data->level;
+
+	return true;
+}
+NOKPROBE_SYMBOL(save_return_addr);
+
+noinline void *return_address(unsigned int level)
+{
+	struct return_address_data data;
+
+	data.level = level + 3;
+	data.addr = NULL;
+
+	arch_stack_walk(save_return_addr, &data, current, NULL);
+
+	if (!data.level)
+		return data.addr;
+	else
+		return NULL;
+
+}
+EXPORT_SYMBOL_GPL(return_address);
+NOKPROBE_SYMBOL(return_address);