[lsan] ppc64: dynamically pick address range for allocator

[MaskRay]

Summary

For ppc64 PIE, it seems that [0xa00000000000,0xc00000000000) may be occupied
which will lead to a segfault in certain kernel configurations
(clang-ppc64le-rhel). Use the !kUsingConstantSpaceBeg code path like Fuchsia.

[nemanjai]

This certainly fixes all the lsan issues on Ubuntu 18.04, leaving only one failure in the CRT test:
CRT-powerpc64le-linux :: dso_handle.cpp

I'll try to see what that's all about.

[MaskRay]

In D121257#3370642, @nemanjai wrote:

This certainly fixes all the lsan issues on Ubuntu 18.04,

Thanks for testing and investigating! If you accept this patch, I'll push it.

leaving only one failure in the CRT test:
CRT-powerpc64le-linux :: dso_handle.cpp

I'll try to see what that's all about.

Puzzled by this failure :( My ppc64 machine works with the test.

[jsji]

LGTM, asan also uses dynamic allocation, so the performance impact should be acceptable.

This will also increase the kAllocatorSize to 4T, but I guess it is to align with all other platforms, and we should be OK even with RHEL 7.6 (kernel 3.10.0).
Thanks for fixing.

[MaskRay]

Thanks! This is for -fsanitize=leak which is a very uncommon option (most people just use asan). I think the constant address can probably save one or two instructions in malloc like functions, which really helps little.
Aligning the VM space with other targets improving consistency.

compiler-rt/lib/lsan/lsan_allocator.h

struct AP32 {
   using AddressSpaceView = AddressSpaceViewTy;
   typedef NoOpMapUnmapCallback MapUnmapCallback;
   static const uptr kFlags = 0;
 };
 template <typename AddressSpaceView>
 using PrimaryAllocatorASVT = SizeClassAllocator32<AP32<AddressSpaceView>>;
 using PrimaryAllocator = PrimaryAllocatorASVT<LocalAddressSpaceView>;
 #elif defined(__x86_64__) || defined(__powerpc64__) || defined(__s390x__)
-# if SANITIZER_FUCHSIA
+# if SANITIZER_FUCHSIA || defined(__powerpc64__)
 const uptr kAllocatorSpace = ~(uptr)0;
 const uptr kAllocatorSize  =  0x40000000000ULL;  // 4T.
-# elif defined(__powerpc64__)
-const uptr kAllocatorSpace = 0xa0000000000ULL;
-const uptr kAllocatorSize  = 0x20000000000ULL;  // 2T.
 #elif defined(__s390x__)
 const uptr kAllocatorSpace = 0x40000000000ULL;
 const uptr kAllocatorSize = 0x40000000000ULL;  // 4T.
 # else
 const uptr kAllocatorSpace = 0x600000000000ULL;
 const uptr kAllocatorSize  = 0x40000000000ULL;  // 4T.
 # endif
 template <typename AddressSpaceViewTy>