Re: [RFC PATCH v3 4/4] arm64: Handle funtion graph tracer better in the unwinder

From: Madhavan T. Venkataraman
Date: Thu May 06 2021 - 11:20:40 EST

On 5/6/21 9:43 AM, Mark Brown wrote:
> On Mon, May 03, 2021 at 12:36:15PM -0500, madvenka@xxxxxxxxxxxxxxxxxxx wrote:
>> From: "Madhavan T. Venkataraman" <madvenka@xxxxxxxxxxxxxxxxxxx>
>> The Function Graph Tracer modifies the return address of a traced function
>> to a return trampoline (return_to_handler()) to gather tracing data on
>> function return. When the unwinder encounters return_to_handler(), it calls
>> ftrace_graph_get_ret_stack() to lookup the original return address in the
>> return address stack.
> This makes sense to me, I'll need to re-review properly with the changes
> earlier on in the series but should be fine.

I will make changes based on the comments I have received so far and send
out version 4 so everything is current for the next round of review.