[Toybox] Kernighan's awk repo

[enh]

On Thu, Jul 21, 2016 at 9:58 AM, Andy Chu <andychup at gmail.com> wrote:
> On Thu, Jul 21, 2016 at 9:04 AM, enh <enh at google.com> wrote:
>> On Wed, Jul 20, 2016 at 9:20 PM, Andy Chu <andychup at gmail.com> wrote:
>>>> yeah, i'd like to see asan support in toybox's makefile; i'm starting
>>>> to get a small pile of bug reports from the folks running asan Android
>>>> system images, but it's going to be inconvenient to have to deal with
>>>> them on the device rather than just on the host.
>>>
>>> How are they generating test input?
>>
>> this isn't from fuzzing.
>>
>>> When you say "folks running", is
>>> that an automated or manual process?
>>
>> for toybox, afaik, it's just people noticing toybox problems while
>> investigating other things.
>
> OK, so basically there are humans walking around with Android phones
> where every system binary is instrumented with ASAN?  It's cool that
> it's fast enough for that.  As I recall the ASAN slowdown is supposed
> to be within 2x, so I can see that.

it could be you! https://source.android.com/devices/tech/debug/asan.html

there are some people with such phones in their pockets, though even
they're only instrumenting a subset --- the time costs might be
manageable but the space costs aren't (for a mobile device). as you
say below, asan was primarily intended for use when running unit tests
or fuzzing, and some of the design decisions reflect that.

> That said, I agree there's a big advantage to doing it on the host,
> because you can actually drive the binaries with a test suite rather
> than whatever people happen to be doing.  People tend to explore the
> same code paths over and over again, while tests can get into the
> corner cases.  (Not to mention fuzzing, which isn't really possible
> with toybox now.)
>
>>> In case it got lost, these patches I sent out in March added ASAN
>>> support to Toybox's Makefile, as well as scripts for running tests
>>> under the ASAN-instrumented binaries (and other LLVM sanitizers)
>>>
>>> http://lists.landley.net/pipermail/toybox-landley.net/2016-March/008147.html
>>
>> no, i remember that and my plan is to give it a try as soon as i have
>> time. which is why the longer version of my plan is "mention it on the
>> list knowing i won't get round to it for a while, and maybe it'll be
>> easier by the time i get there anyway" :-)
>
> OK, the patches no longer apply since Rob started rewriting parts of
> the related build stuff, but didn't anywhere close to ASAN afaik.  But
> it shouldn't be too hard to checkout a commit as of March and apply
> them.
>
> There are some more instructions here when I reproduce the expr bug
> that was introduced:
>
> http://lists.landley.net/pipermail/toybox-landley.net/2016-April/008214.html
>
> And Rob you clearly never ran that, because the ONLY bug it flagged
> was YOUR bug.  You're simply being ignorant by writing that it's a
> false positive generator.  Please try things before writing long
> messages full of nonsense.
>
> And you're the one who asked for the bwk repo with tests, so I
> published it, so you should actually run it.
>
> I'm not promising to make the patches apply again, but given that I
> showed examples of adding it to toybox, and adding it to bwk, it
> should be straightforward to follow that model.
>
> Andy



-- 
Elliott Hughes - http://who/enh - http://jessies.org/~enh/
Android native code/tools questions? Mail me/drop by/add me as a reviewer.