pkgs/development/compilers/llvm/aarch64.patch

   1 --- lib/Support/Unix/Memory.inc
   2 +++ lib/Support/Unix/Memory.inc
   3 @@ -126,8 +126,12 @@
   4    Result.Address = Addr;
   5    Result.Size = NumPages*PageSize;
   6
   7 -  if (PFlags & MF_EXEC)
   8 -    Memory::InvalidateInstructionCache(Result.Address, Result.Size);
   9 +  // Rely on protectMappedMemory to invalidate instruction cache.
  10 +  if (PFlags & MF_EXEC) {
  11 +    EC = Memory::protectMappedMemory (Result, PFlags);
  12 +    if (EC != std::error_code())
  13 +      return MemoryBlock();
  14 +  }
  15
  16    return Result;
  17  }
  18 @@ -156,15 +160,31 @@
  19      return std::error_code(EINVAL, std::generic_category());
  20
  21    int Protect = getPosixProtectionFlags(Flags);
  22 -
  23    uintptr_t Start = alignAddr((uint8_t *)M.Address - PageSize + 1, PageSize);
  24    uintptr_t End = alignAddr((uint8_t *)M.Address + M.Size, PageSize);
  25 +
  26 +  bool InvalidateCache = (Flags & MF_EXEC);
  27 +
  28 +#if defined(__arm__) || defined(__aarch64__)
  29 +  // Certain ARM implementations treat icache clear instruction as a memory read,
  30 +  // and CPU segfaults on trying to clear cache on !PROT_READ page.  Therefore we need
  31 +  // to temporarily add PROT_READ for the sake of flushing the instruction caches.
  32 +  if (InvalidateCache && !(Protect & PROT_READ)) {
  33 +    int Result = ::mprotect((void *)Start, End - Start, Protect | PROT_READ);
  34 +    if (Result != 0)
  35 +      return std::error_code(errno, std::generic_category());
  36 +
  37 +    Memory::InvalidateInstructionCache(M.Address, M.Size);
  38 +    InvalidateCache = false;
  39 +  }
  40 +#endif
  41 +
  42    int Result = ::mprotect((void *)Start, End - Start, Protect);
  43
  44    if (Result != 0)
  45      return std::error_code(errno, std::generic_category());
  46
  47 -  if (Flags & MF_EXEC)
  48 +  if (InvalidateCache)
  49      Memory::InvalidateInstructionCache(M.Address, M.Size);
  50
  51    return std::error_code();