[PATCH] D48445: [sanitizer] Use "fast mmap" kernel flag for shadow memory on macOS 10.13.4+

[Dan Liew via Phabricator via llvm-commits]

delcypher requested changes to this revision.
delcypher added inline comments.
This revision now requires changes to proceed.


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Comment at: lib/sanitizer_common/sanitizer_posix_libcdep.cc:331
+// giant memory regions.
+#define kXnuFastMmapFd 0x4
+bool use_xnu_fast_mmap = false;
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Is there a reason the `use_xnu_fast_mmap` isn't pushed into the Darwin implementation of `internal_mmap()`? Wouldn't it make more sense to be there given that xnu_fast_mmap is Darwin specific?


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Comment at: lib/sanitizer_common/sanitizer_posix_libcdep.cc:391
   if (fd == -1) flags |= MAP_ANON;
+  if (fd == -1 && use_xnu_fast_mmap) fd = kXnuFastMmapFd;
 
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Again can't we move this into the Darwin implementation of `internal_mmap()`. This will also mean we avoid duplicating code.


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Comment at: lib/tsan/rtl/tsan_rtl.cc:361
+  __sanitizer::InitializePlatformEarly();
   InitializePlatformEarly();
+
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`__sanitizer::InitializePlatformEarly()` is different from `InitializePlatformEarly()` that's called immediately afterwards?


Repository:
  rCRT Compiler Runtime

https://reviews.llvm.org/D48445