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Subject: Re: [RFC PATCH v2 3/4] arm64: Detect FTRACE cases that make the stack
 trace unreliable
To:     Mark Brown <broonie@kernel.org>, mark.rutland@arm.com
Cc:     jpoimboe@redhat.com, jthierry@redhat.com, catalin.marinas@arm.com,
        will@kernel.org, linux-arm-kernel@lists.infradead.org,
        live-patching@vger.kernel.org, linux-kernel@vger.kernel.org
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 <20210405204313.21346-1-madvenka@linux.microsoft.com>
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 <20210408165825.GP4516@sirena.org.uk>
From:   "Madhavan T. Venkataraman" <madvenka@linux.microsoft.com>
Message-ID: <eacc6098-a15f-c07a-2730-cb16cb8e1982@linux.microsoft.com>
Date:   Thu, 8 Apr 2021 14:23:39 -0500
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On 4/8/21 11:58 AM, Mark Brown wrote:
> On Mon, Apr 05, 2021 at 03:43:12PM -0500, madvenka@linux.microsoft.com wrote:
>> From: "Madhavan T. Venkataraman" <madvenka@linux.microsoft.com>
>>
>> When CONFIG_DYNAMIC_FTRACE_WITH_REGS is enabled and tracing is activated
>> for a function, the ftrace infrastructure is called for the function at
>> the very beginning. Ftrace creates two frames:
> 
> This looks good to me however I'd really like someone who has a firmer
> understanding of what ftrace is doing to double check as it is entirely
> likely that I am missing cases here, it seems likely that if I am
> missing stuff it's extra stuff that needs to be added and we're not
> actually making use of the reliability information yet.
> 

OK. So, do you have some specific reviewer(s) in mind? Apart from yourself, Mark Rutland and
Josh Poimboeuf, these are some reviewers I can think of (in alphabetical order):

AKASHI Takahiro <takahiro.akashi@linaro.org>
Ard Biesheuvel <ard.biesheuvel@linaro.org>
Catalin Marinas <catalin.marinas@arm.com>
Josh Poimboeuf <jpoimboe@redhat.com>
Steven Rostedt (VMware) <rostedt@goodmis.org>
Torsten Duwe <duwe@suse.de>
Will Deacon <will@kernel.org>

Sorry if I missed out any of the other experts.

Thanks.

Madhavan