[llvm-dev] ASan port for Myriad RTEMS

[Walter Lee via llvm-dev]

On Fri, May 4, 2018 at 6:21 PM Kostya Serebryany <kcc at google.com> wrote:

> On RAM...

> You chose the 32-byte shadow granularity to reduce the RAM overhead,
> but I am afraid this will actually increase it due to extra alignment
requirements,
> especially if an average allocation on your typical application is small.


Good point.  I will run our test suite with 8-byte shadow granularity and
do some measurements.

In general, the memory constraint hasn't been as big an issue as I
initially thought.  The mitigating factor is that we are focused on unit
tests as opposed to running the full blown application.


> The pointers are 32-bit, right?
> Given how RAM-constrained your environment is, maybe you should consider
something more like HWASAN instead of ASAN.
> https://clang.llvm.org/docs/HardwareAssistedAddressSanitizerDesign.html
> But you may not have enough address bits. :(

Pointers are 32 bits.  Interesting idea, but I agree I don't think we have
enough bits.  Even ignoring the sparsely used lower addresses, DDR + cache
bit leaves us with only 2 bits.

Thanks,

Walter