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Date:   Fri, 15 Apr 2022 14:43:15 -0700
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Subject: Re: [RFC PATCH 0/2] kunit: Support redirecting function calls
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To:     Brendan Higgins <brendanhiggins@google.com>,
        David Gow <davidgow@google.com>
Cc:     Daniel Latypov <dlatypov@google.com>,
        Kees Cook <keescook@chromium.org>,
        Shuah Khan <skhan@linuxfoundation.org>,
        kunit-dev@googlegroups.com, linux-kselftest@vger.kernel.org,
        linux-kernel@vger.kernel.org, Steven Rostedt <rostedt@goodmis.org>
References: <20220318021314.3225240-1-davidgow@google.com>
 <20220318092159.6f275782@gandalf.local.home>
 <CAFd5g461Poh37o=3m6EXppdX7oS0D5vZxvFAEtzJMwtBD1VJEw@mail.gmail.com>
From:   Steve Muckle <smuckle@google.com>
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On 4/4/22 13:13, Brendan Higgins wrote:
> On Fri, Mar 18, 2022 at 9:22 AM Steven Rostedt <rostedt@goodmis.org> wrote:
>>
>> On Fri, 18 Mar 2022 10:13:12 +0800
>> David Gow <davidgow@google.com> wrote:
>>
>>> Does either (or both) of these features sound useful, and is this
>>> sort-of API the right model? (Personally, I think there's a reasonable
>>> scope for both.) Is anything obviously missing or wrong? Do the names,
>>> descriptions etc. make any sense?
>>
>> Obviously I'm biased toward the ftrace solution ;-)
> 
> Personally, I like providing both - as long as we can keep the
> interface the same.
> 
> Ftrace is less visually invasive, but it is also less flexible in
> capabilities, and requires substantial work to support on new
> architectures.

The general feature looks useful to me. I'm not sure the ftrace based 
API is worth it given it is only offering a visual improvement and has 
some drawbacks compared to the other implementation (won't work with 
inline functions, dependencies on other features). Livepatch is absent 
on arm64 which mostly rules it out for my purposes (Android Generic 
Kernel Image testing).

cheers,
Steve