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Subject: Re: [RFC PATCH v3 4/4] arm64: Handle funtion graph tracer better in
 the unwinder
To:     Mark Brown <broonie@kernel.org>
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        catalin.marinas@arm.com, will@kernel.org, jmorris@namei.org,
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 <20210503173615.21576-1-madvenka@linux.microsoft.com>
 <20210503173615.21576-5-madvenka@linux.microsoft.com>
 <20210506144352.GF4642@sirena.org.uk>
From:   "Madhavan T. Venkataraman" <madvenka@linux.microsoft.com>
Message-ID: <f6616a1a-1291-b9b1-17d6-aed40f4a2b55@linux.microsoft.com>
Date:   Thu, 6 May 2021 10:20:35 -0500
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On 5/6/21 9:43 AM, Mark Brown wrote:
> On Mon, May 03, 2021 at 12:36:15PM -0500, madvenka@linux.microsoft.com wrote:
>> From: "Madhavan T. Venkataraman" <madvenka@linux.microsoft.com>
>>
>> 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.

Thanks!

Madhavan