8 files changed, 18 insertions, 15 deletions
diff --git a/llvm/lib/ExecutionEngine/JITLink/JITLink.cpp b/llvm/lib/ExecutionEngine/JITLink/JITLink.cpp
index 3169011f082..1cea043f761 100644
--- a/llvm/lib/ExecutionEngine/JITLink/JITLink.cpp
+++ b/llvm/lib/ExecutionEngine/JITLink/JITLink.cpp
@@ -194,12 +194,12 @@ InProcessMemoryManager::allocate(const SegmentsRequestMap &Request) {
   for (auto &KV : Request) {
     auto &Seg = KV.second;
 
-    if (Seg.getContentAlignment() > sys::Process::getPageSize())
+    if (Seg.getContentAlignment() > sys::Process::getPageSizeEstimate())
       return make_error<StringError>("Cannot request higher than page "
                                      "alignment",
                                      inconvertibleErrorCode());
 
-    if (sys::Process::getPageSize() % Seg.getContentAlignment() != 0)
+    if (sys::Process::getPageSizeEstimate() % Seg.getContentAlignment() != 0)
       return make_error<StringError>("Page size is not a multiple of "
                                      "alignment",
                                      inconvertibleErrorCode());
diff --git a/llvm/lib/ExecutionEngine/Orc/OrcABISupport.cpp b/llvm/lib/ExecutionEngine/Orc/OrcABISupport.cpp
index 4bf52864107..8ed23de419d 100644
--- a/llvm/lib/ExecutionEngine/Orc/OrcABISupport.cpp
+++ b/llvm/lib/ExecutionEngine/Orc/OrcABISupport.cpp
@@ -147,7 +147,7 @@ Error OrcAArch64::emitIndirectStubsBlock(IndirectStubsInfo &StubsInfo,
   const unsigned StubSize = IndirectStubsInfo::StubSize;
 
   // Emit at least MinStubs, rounded up to fill the pages allocated.
-  unsigned PageSize = sys::Process::getPageSize();
+  static const unsigned PageSize = sys::Process::getPageSizeEstimate();
   unsigned NumPages = ((MinStubs * StubSize) + (PageSize - 1)) / PageSize;
   unsigned NumStubs = (NumPages * PageSize) / StubSize;
 
@@ -229,7 +229,7 @@ Error OrcX86_64_Base::emitIndirectStubsBlock(IndirectStubsInfo &StubsInfo,
   const unsigned StubSize = IndirectStubsInfo::StubSize;
 
   // Emit at least MinStubs, rounded up to fill the pages allocated.
-  unsigned PageSize = sys::Process::getPageSize();
+  static const unsigned PageSize = sys::Process::getPageSizeEstimate();
   unsigned NumPages = ((MinStubs * StubSize) + (PageSize - 1)) / PageSize;
   unsigned NumStubs = (NumPages * PageSize) / StubSize;
 
@@ -497,7 +497,7 @@ Error OrcI386::emitIndirectStubsBlock(IndirectStubsInfo &StubsInfo,
   const unsigned StubSize = IndirectStubsInfo::StubSize;
 
   // Emit at least MinStubs, rounded up to fill the pages allocated.
-  unsigned PageSize = sys::Process::getPageSize();
+  static const unsigned PageSize = sys::Process::getPageSizeEstimate();
   unsigned NumPages = ((MinStubs * StubSize) + (PageSize - 1)) / PageSize;
   unsigned NumStubs = (NumPages * PageSize) / StubSize;
 
@@ -683,7 +683,7 @@ Error OrcMips32_Base::emitIndirectStubsBlock(IndirectStubsInfo &StubsInfo,
   const unsigned StubSize = IndirectStubsInfo::StubSize;
 
   // Emit at least MinStubs, rounded up to fill the pages allocated.
-  unsigned PageSize = sys::Process::getPageSize();
+  static const unsigned PageSize = sys::Process::getPageSizeEstimate();
   unsigned NumPages = ((MinStubs * StubSize) + (PageSize - 1)) / PageSize;
   unsigned NumStubs = (NumPages * PageSize) / StubSize;
 
@@ -929,7 +929,7 @@ Error OrcMips64::emitIndirectStubsBlock(IndirectStubsInfo &StubsInfo,
   const unsigned StubSize = IndirectStubsInfo::StubSize;
 
   // Emit at least MinStubs, rounded up to fill the pages allocated.
-  unsigned PageSize = sys::Process::getPageSize();
+  static const unsigned PageSize = sys::Process::getPageSizeEstimate();
   unsigned NumPages = ((MinStubs * StubSize) + (PageSize - 1)) / PageSize;
   unsigned NumStubs = (NumPages * PageSize) / StubSize;
 
diff --git a/llvm/lib/ExecutionEngine/SectionMemoryManager.cpp b/llvm/lib/ExecutionEngine/SectionMemoryManager.cpp
index ba277796dd5..2c0cfeb8a9a 100644
--- a/llvm/lib/ExecutionEngine/SectionMemoryManager.cpp
+++ b/llvm/lib/ExecutionEngine/SectionMemoryManager.cpp
@@ -172,7 +172,7 @@ bool SectionMemoryManager::finalizeMemory(std::string *ErrMsg) {
 }
 
 static sys::MemoryBlock trimBlockToPageSize(sys::MemoryBlock M) {
-  static const size_t PageSize = sys::Process::getPageSize();
+  static const size_t PageSize = sys::Process::getPageSizeEstimate();
 
   size_t StartOverlap =
       (PageSize - ((uintptr_t)M.base() % PageSize)) % PageSize;
@@ -244,7 +244,7 @@ public:
                        unsigned Flags, std::error_code &EC) override {
     // allocateMappedMemory calls mmap(2). We round up a request size
     // to page size to get extra space for free.
-    static const size_t PageSize = sys::Process::getPageSize();
+    static const size_t PageSize = sys::Process::getPageSizeEstimate();
     size_t ReqBytes = (NumBytes + PageSize - 1) & ~(PageSize - 1);
     return sys::Memory::allocateMappedMemory(ReqBytes, NearBlock, Flags, EC);
   }
diff --git a/llvm/lib/Support/MemoryBuffer.cpp b/llvm/lib/Support/MemoryBuffer.cpp
index 3f13d4d3552..92e39e118b9 100644
--- a/llvm/lib/Support/MemoryBuffer.cpp
+++ b/llvm/lib/Support/MemoryBuffer.cpp
@@ -417,7 +417,7 @@ static ErrorOr<std::unique_ptr<MB>>
 getOpenFileImpl(int FD, const Twine &Filename, uint64_t FileSize,
                 uint64_t MapSize, int64_t Offset, bool RequiresNullTerminator,
                 bool IsVolatile) {
-  static int PageSize = sys::Process::getPageSize();
+  static int PageSize = sys::Process::getPageSizeEstimate();
 
   // Default is to map the full file.
   if (MapSize == uint64_t(-1)) {
diff --git a/llvm/lib/Support/Unix/Memory.inc b/llvm/lib/Support/Unix/Memory.inc
index b8f5df5f72e..affdb7e70d9 100644
--- a/llvm/lib/Support/Unix/Memory.inc
+++ b/llvm/lib/Support/Unix/Memory.inc
@@ -103,7 +103,7 @@ Memory::allocateMappedMemory(size_t NumBytes,
   // Use any near hint and the page size to set a page-aligned starting address
   uintptr_t Start = NearBlock ? reinterpret_cast<uintptr_t>(NearBlock->base()) +
                                       NearBlock->size() : 0;
-  static const size_t PageSize = Process::getPageSize();
+  static const size_t PageSize = Process::getPageSizeEstimate();
   if (Start && Start % PageSize)
     Start += PageSize - Start % PageSize;
 
@@ -149,7 +149,7 @@ Memory::releaseMappedMemory(MemoryBlock &M) {
 
 std::error_code
 Memory::protectMappedMemory(const MemoryBlock &M, unsigned Flags) {
-  static const size_t PageSize = Process::getPageSize();
+  static const size_t PageSize = Process::getPageSizeEstimate();
   if (M.Address == nullptr || M.Size == 0)
     return std::error_code();
 
diff --git a/llvm/lib/Support/Unix/Path.inc b/llvm/lib/Support/Unix/Path.inc
index fb14422ba33..c2f78e79b87 100644
--- a/llvm/lib/Support/Unix/Path.inc
+++ b/llvm/lib/Support/Unix/Path.inc
@@ -786,7 +786,7 @@ const char *mapped_file_region::const_data() const {
 }
 
 int mapped_file_region::alignment() {
-  return Process::getPageSize();
+  return Process::getPageSizeEstimate();
 }
 
 std::error_code detail::directory_iterator_construct(detail::DirIterState &it,
diff --git a/llvm/lib/Support/Unix/Process.inc b/llvm/lib/Support/Unix/Process.inc
index 7c834f97114..78c123493e1 100644
--- a/llvm/lib/Support/Unix/Process.inc
+++ b/llvm/lib/Support/Unix/Process.inc
@@ -69,7 +69,7 @@ static std::pair<std::chrono::microseconds, std::chrono::microseconds> getRUsage
 
 // On Cygwin, getpagesize() returns 64k(AllocationGranularity) and
 // offset in mmap(3) should be aligned to the AllocationGranularity.
-unsigned Process::getPageSize() {
+Expected<unsigned> Process::getPageSize() {
 #if defined(HAVE_GETPAGESIZE)
   static const int page_size = ::getpagesize();
 #elif defined(HAVE_SYSCONF)
@@ -77,6 +77,9 @@ unsigned Process::getPageSize() {
 #else
 #error Cannot get the page size on this machine
 #endif
+  if (page_size == -1)
+    return errorCodeToError(std::error_code(errno, std::generic_category()));
+
   return static_cast<unsigned>(page_size);
 }
 
diff --git a/llvm/lib/Support/Windows/Process.inc b/llvm/lib/Support/Windows/Process.inc
index b3c9aa0b83c..4b91f9f7fc6 100644
--- a/llvm/lib/Support/Windows/Process.inc
+++ b/llvm/lib/Support/Windows/Process.inc
@@ -56,7 +56,7 @@ static unsigned computePageSize() {
   return static_cast<unsigned>(info.dwPageSize);
 }
 
-unsigned Process::getPageSize() {
+Expected<unsigned> Process::getPageSize() {
   static unsigned Ret = computePageSize();
   return Ret;
 }