[llvm-dev] Intel MPX support (instrumentation pass similar to gcc's Pointer Checker)

[Dmitrii Kuvaiskii via llvm-dev]

Thank you Sergey and Konstantin for useful suggestions. We are
currently bootstrapping the infrastructure for our experiments. We
would like to make a sufficiently comprehensive report, with not only
the performance/memory overhead numbers, but also discussing and
evaluating security guarantees. I will also examine the available
source codes (ASan, gcc-mpx, SoftBound) and will spend some pages on a
discussion of the different approaches (trying to do science, you see
:)).

Btw, I will target only deterministic memory-safety no-code-changes
approaches that protect against spatial errors (I will probably
include also ASan and SoftBoundCETS with temporal errors' protection
in the results as well). The only technique (except Pointer Checker,
ASan, and SoftBound) I know of is Baggy Bounds Checking from MSR, but
it seems to be closed-source and Windows-oriented. If anyone can
suggest some other technique that could be evaluated here, please
inform me.

Anyway, before putting the techreport online, I will send the draft to
everyone who took part in this conversation, just to be on the safe
side and correct any bugs/wrong conclusions.

On Tue, Feb 9, 2016 at 3:24 PM, Sergey Ostanevich <sergos.gnu at gmail.com> wrote:
> Dmitrii, all,
>
> Please note, that GCC 5.3 had a significant update to the MPX code quality -
> please, use this version as reference.
>
> Regards,
> Sergos
>
> On Tue, Feb 9, 2016 at 12:49 AM, Kostya Serebryany via llvm-dev
> <llvm-dev at lists.llvm.org> wrote:
>>
>>
>>
>> On Thu, Feb 4, 2016 at 10:40 AM, Kostya Serebryany <kcc at google.com> wrote:
>>>
>>>
>>>
>>> On Thu, Feb 4, 2016 at 4:59 AM, Dmitrii Kuvaiskii
>>> <Dmitrii.Kuvaiskii at tu-dresden.de> wrote:
>>>>
>>>> >> Recently I played with MPX support on Intel C/C++ Compiler (icc).
>>>> >> This
>>>> >> implementation looks *much* better, with the following example
>>>> >> overheads: 1.2X on "raytrace", 1.25X on "bodytrack", 1.08X on
>>>> >> "streamcluster". So the common overheads are in the range of 15%-25%!
>>>> > That's interesting.
>>>> > Are you sure you are instrumenting both reads and writes with icc?
>>>>
>>>> Yes, here are the exact flags I add to the usual build configuration:
>>>>   -xHOST -check-pointers-mpx:rw
>>>
>>>
>>> Interesting, looking forward to reading your report!
>>>>
>>>>
>>>> Note "rw" which stands for protecting read and write accesses. In the
>>>> future, I will analyze how different flags affect ASan / SoftBoundCETS
>>>> / gcc-mpx / icc-mpx.
>>>> I will also use a set of microbenchmarks/benchmarks (e.g., RIPE) to
>>>> test the protection provided.
>>>>
>>>> > SPEC2006 is well know so it could be useful. Especially 483.xalancbmk
>>>> > Besides, maybe you could take something that is not strictly a
>>>> > benchmark.
>>>> > E.g. take pdfium_test (https://pdfium.googlesource.com/pdfium/) and
>>>> > feed
>>>> > several large pdf files to it.
>>>>
>>>> Thanks, I will report the SPEC2006 numbers as well.
>>>>
>>>
>>> Note that SPEC2006 has several know bugs that trigger under asan.
>>>
>>> https://github.com/google/sanitizers/wiki/AddressSanitizerRunningSpecBenchmarks
>>> has a patch that makes SPEC2006 pass with asan.
>>> Some of these bugs and maybe others may also trigger with an MPX checker.
>>
>>
>> Another note: please also try to document the memory footprint.
>> One of unfortunate features of MPX is its large metadata storage which may
>> in
>> theory consume as much as 4x more RAM than the application itself.
>>
>> --kcc
>>
>>>
>>>
>>> --kcc
>>>
>>>> --
>>>> Yours sincerely,
>>>> Dmitrii Kuvaiskii
>>>
>>>
>>
>>
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>

-- 
Yours sincerely,
Dmitrii Kuvaiskii