[PATCH] D65851: [Sanitizer] Using huge page on FreeBSD for shadow mapping

[Vitaly Buka via Phabricator via llvm-commits]

vitalybuka added inline comments.


================
Comment at: compiler-rt/lib/asan/asan_shadow_setup.cpp:33
   DecreaseTotalMmap(size);  // Don't count the shadow against mmap_limit_mb.
+#if SANITIZER_LINUX
+  // Only Linux supports THP feature
----------------
Please remove #if and use MmapFixedSuperPage always


================
Comment at: compiler-rt/lib/sanitizer_common/sanitizer_common.h:103
      WARN_UNUSED_RESULT;
+bool MmapFixedSuperPage(uptr fixed_addr, uptr size, const char *name = nullptr);
 void *MmapNoReserveOrDie(uptr size, const char *mem_type);
----------------

WARN_UNUSED_RESULT?


================
Comment at: compiler-rt/lib/sanitizer_common/sanitizer_common.h:103
      WARN_UNUSED_RESULT;
+bool MmapFixedSuperPage(uptr fixed_addr, uptr size, const char *name = nullptr);
 void *MmapNoReserveOrDie(uptr size, const char *mem_type);
----------------
vitalybuka wrote:
> 
> WARN_UNUSED_RESULT?
MmapFixedSuperPage -> MmapFixedSuperNoReserve


================
Comment at: compiler-rt/lib/sanitizer_common/sanitizer_posix_libcdep.cpp:322
 }
 
+bool MmapFixedSuperPage(uptr fixed_addr, uptr size, const char *name) {
----------------
Please extract
```
static bool MmapFixed(uptr fixed_addr, uptr size, int additional_flags, const char *name) {
  size = RoundUpTo(size, GetPageSizeCached());
  fixed_addr = RoundDownTo(fixed_addr, GetPageSizeCached());
  uptr p = MmapNamed((void *)fixed_addr, size, PROT_READ | PROT_WRITE,
                     MAP_PRIVATE | MAP_FIXED | MAP_ANON | additional_flags, name);
  int reserrno;
  if (internal_iserror(p, &reserrno)) {
    Report("ERROR: %s failed to "
           "allocate 0x%zx (%zd) bytes at address %zx (errno: %d)\n",
           SanitizerToolName, size, size, fixed_addr, reserrno);
    return false;
  }
  IncreaseTotalMmap(size);
  return true;
}
```

and use it here and in MmapFixedNoReserve


Repository:
  rCRT Compiler Runtime

CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D65851/new/

https://reviews.llvm.org/D65851