quoted

quoted

diff --git a/arch/arm64/kernel/return_address.c b/arch/arm64/kernel/return_address.c
index a6d18755652f..92a0f4d434e4 100644
--- a/arch/arm64/kernel/return_address.c
+++ b/arch/arm64/kernel/return_address.c

@@ -35,15 +35,11 @@ NOKPROBE_SYMBOL(save_return_addr);
 void *return_address(unsigned int level)
 {
 	struct return_address_data data;
-	struct stackframe frame;
 
 	data.level = level + 2;
 	data.addr = NULL;
 
-	start_backtrace(&frame,
-			(unsigned long)__builtin_frame_address(0),
-			(unsigned long)return_address);
-	walk_stackframe(current, &frame, save_return_addr, &data);
+	arch_stack_walk(save_return_addr, &data, current, NULL);
 
 	if (!data.level)
 		return data.addr;

Nor that arch_stack_walk() will start with it's caller, so
return_address() will be included in the trace where it wasn't
previously, which implies we need to skip an additional level.

You are correct. I will fix this. Thanks for catching this.

quoted

That said, I'm not entirely sure why we need to skip 2 levels today; it
might be worth checking that's correct.

AFAICT, return_address() acts like builtin_return_address(). That is, it
returns the address of the caller. If func() calls return_address(),
func() wants its caller's address. So, return_address() and func() need to
be skipped.

I will change it to skip 3 levels instead of 2.

Actually, I take that back. I remember now. return_address() used to start
with PC=return_address(). That is, it used to start with itself. arch_stack_walk()
starts with its caller which, in this case, is return_address(). So, I don't need
to change anything.

Do you agree?

Madhavan