[PATCH] D20084: [sanitizer] Initial implementation of a Hardened Allocator

[Alexander Potapenko via llvm-commits]

glider added inline comments.

================
Comment at: projects/compiler-rt/lib/hardened_allocator/scudo_allocator.cc:278
@@ +277,3 @@
+  void Initialize(const AllocatorOptions &options) {
+    CHECK(TestCPUFeature(SSE4_2)); // for crc32
+    DeallocationTypeMismatch = options.DeallocationTypeMismatch;
----------------
filcab wrote:
> glider wrote:
> > Despite SSE 4.2 may be quite common at Google, I don't think it's a good idea to bail out if it's unsupported.
> > Note TestCPUFeature() doesn't work on AMD processors yet.
> Source files are compiled assuming that feature is available.
> We'll have to add a fallback checksum (plus change build and this check) to address this comment.
> 
> I would be ok with keeping the SSE4.2 requirement until we get a non-zero amount of requests/bug reports.
> 
> P.S: http://store.steampowered.com/hwsurvey (first result for "hardware survey". It's clearly biased, but I'd guess developer CPUs are also biased to be more recent/powerful than an average computer) puts SSE4.2 adoption at ~80%.
> 
Well, IIUC right now the implementation just aborts for AMD processors, which are among those ~80%.


http://reviews.llvm.org/D20084