* ASan: move allocator base to avoid conflict with high-entropy ASLR

for x86-64 Linux. Patch taken from LLVM 17.

debian/changelog

@@ -3,6 +3,8 @@ llvm-toolchain-16 (1:16.0.6-24) UNRELEASED; urgency=medium
   [ Matthias Klose ]
   * Add a stage1 profile to disable curl, grpc and spirv.
   * Build with --as-needed.
+  * ASan: move allocator base to avoid conflict with high-entropy ASLR
+    for x86-64 Linux. Patch taken from LLVM 17.
 
  -- Matthias Klose <doko@debian.org>  Sat, 16 Mar 2024 22:12:22 +0100
 

debian/patches/fb77ca05ffb4f8e666878f2f6718a9fb4d686839.diff

@@ -0,0 +1,22 @@
+diff --git a/compiler-rt/lib/asan/asan_allocator.h b/compiler-rt/lib/asan/asan_allocator.h
+index 0b4dbf03bb9d53..6a12a6c6025283 100644
+--- a/compiler-rt/lib/asan/asan_allocator.h
++++ b/compiler-rt/lib/asan/asan_allocator.h
+@@ -143,11 +143,15 @@ typedef DefaultSizeClassMap SizeClassMap;
+ const uptr kAllocatorSpace = ~(uptr)0;
+ const uptr kAllocatorSize  =  0x8000000000ULL;  // 500G
+ typedef DefaultSizeClassMap SizeClassMap;
+-# else
++#  elif SANITIZER_APPLE
+ const uptr kAllocatorSpace = 0x600000000000ULL;
+ const uptr kAllocatorSize  =  0x40000000000ULL;  // 4T.
+ typedef DefaultSizeClassMap SizeClassMap;
+-# endif
++#  else
++const uptr kAllocatorSpace = 0x500000000000ULL;
++const uptr kAllocatorSize = 0x40000000000ULL;  // 4T.
++typedef DefaultSizeClassMap SizeClassMap;
++#  endif
+ template <typename AddressSpaceViewTy>
+ struct AP64 {  // Allocator64 parameters. Deliberately using a short name.
+   static const uptr kSpaceBeg = kAllocatorSpace;

debian/patches/series

@@ -156,3 +156,4 @@ D158066-simd-ppc64el.patch
 D142688-loong64.diff
 remove-unused-imp-module.diff
 libsanitizer-timebits.diff
+fb77ca05ffb4f8e666878f2f6718a9fb4d686839.diff