This patch adds memory support functions which will later be used to implement section-specific protection handling in MCJIT.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@164249 91177308-0d34-0410-b5e6-96231b3b80d8

3 files changed, 325 insertions, 90 deletions

diff --git a/lib/Support/Memory.cpp b/lib/Support/Memory.cpp
index 3cc8f5e..12f0838 100644
--- a/lib/Support/Memory.cpp
+++ b/lib/Support/Memory.cpp
@@ -16,10 +16,6 @@
 #include "llvm/Support/Valgrind.h"
 #include "llvm/Config/config.h"
 
-namespace llvm {
-using namespace sys;
-}
-
 // Include the platform-specific parts of this class.
 #ifdef LLVM_ON_UNIX
 #include "Unix/Memory.inc"
@@ -27,51 +23,3 @@ using namespace sys;
 #ifdef LLVM_ON_WIN32
 #include "Windows/Memory.inc"
 #endif
-
-extern "C" void sys_icache_invalidate(const void *Addr, size_t len);
-
-/// InvalidateInstructionCache - Before the JIT can run a block of code
-/// that has been emitted it must invalidate the instruction cache on some
-/// platforms.
-void llvm::sys::Memory::InvalidateInstructionCache(const void *Addr,
-                                                   size_t Len) {
-
-// icache invalidation for PPC and ARM.
-#if defined(__APPLE__)
-
-#  if (defined(__POWERPC__) || defined (__ppc__) || \
-     defined(_POWER) || defined(_ARCH_PPC)) || defined(__arm__)
-  sys_icache_invalidate(const_cast<void *>(Addr), Len);
-#  endif
-
-#else
-
-#  if (defined(__POWERPC__) || defined (__ppc__) || \
-       defined(_POWER) || defined(_ARCH_PPC)) && defined(__GNUC__)
-  const size_t LineSize = 32;
-
-  const intptr_t Mask = ~(LineSize - 1);
-  const intptr_t StartLine = ((intptr_t) Addr) & Mask;
-  const intptr_t EndLine = ((intptr_t) Addr + Len + LineSize - 1) & Mask;
-
-  for (intptr_t Line = StartLine; Line < EndLine; Line += LineSize)
-    asm volatile("dcbf 0, %0" : : "r"(Line));
-  asm volatile("sync");
-
-  for (intptr_t Line = StartLine; Line < EndLine; Line += LineSize)
-    asm volatile("icbi 0, %0" : : "r"(Line));
-  asm volatile("isync");
-#  elif defined(__arm__) && defined(__GNUC__)
-  // FIXME: Can we safely always call this for __GNUC__ everywhere?
-  const char *Start = static_cast<const char *>(Addr);
-  const char *End = Start + Len;
-  __clear_cache(const_cast<char *>(Start), const_cast<char *>(End));
-#  elif defined(__mips__)
-  const char *Start = static_cast<const char *>(Addr);
-  cacheflush(const_cast<char *>(Start), Len, BCACHE);
-#  endif
-
-#endif  // end apple
-
-  ValgrindDiscardTranslations(Addr, Len);
-}
diff --git a/lib/Support/Unix/Memory.inc b/lib/Support/Unix/Memory.inc
index 2e301f6..9a8abd2 100644
--- a/lib/Support/Unix/Memory.inc
+++ b/lib/Support/Unix/Memory.inc
@@ -13,6 +13,7 @@
 
 #include "Unix.h"
 #include "llvm/Support/DataTypes.h"
+#include "llvm/Support/ErrorHandling.h"
 #include "llvm/Support/Process.h"
 
 #ifdef HAVE_SYS_MMAN_H
@@ -31,14 +32,138 @@
 #  endif
 #endif
 
+extern "C" void sys_icache_invalidate(const void *Addr, size_t len);
+
+namespace {
+
+int getPosixProtectionFlags(unsigned Flags) {
+  switch (Flags) {
+  case llvm::sys::Memory::MF_READ:
+    return PROT_READ;
+  case llvm::sys::Memory::MF_WRITE:
+    return PROT_WRITE;
+  case llvm::sys::Memory::MF_READ|llvm::sys::Memory::MF_WRITE:
+    return PROT_READ | PROT_WRITE;
+  case llvm::sys::Memory::MF_READ|llvm::sys::Memory::MF_EXEC:
+    return PROT_READ | PROT_EXEC;
+  case llvm::sys::Memory::MF_READ |
+	 llvm::sys::Memory::MF_WRITE |
+	 llvm::sys::Memory::MF_EXEC:
+    return PROT_READ | PROT_WRITE | PROT_EXEC;
+  case llvm::sys::Memory::MF_EXEC:
+    return PROT_EXEC;
+  default:
+    llvm_unreachable("Illegal memory protection flag specified!");
+  }
+  // Provide a default return value as required by some compilers.
+  return PROT_NONE;
+}
+
+} // namespace
+
+namespace llvm {
+namespace sys {
+
+MemoryBlock
+Memory::allocateMappedMemory(size_t NumBytes,
+                             const MemoryBlock *const NearBlock,
+                             unsigned PFlags,
+                             error_code &EC) {
+  EC = error_code::success();
+  if (NumBytes == 0)
+    return MemoryBlock();
+
+  static const size_t PageSize = Process::GetPageSize();
+  const size_t NumPages = (NumBytes+PageSize-1)/PageSize;
+
+  int fd = -1;
+#ifdef NEED_DEV_ZERO_FOR_MMAP
+  static int zero_fd = open("/dev/zero", O_RDWR);
+  if (zero_fd == -1) {
+    EC = error_code(errno, system_category());
+    return MemoryBlock();
+  }
+  fd = zero_fd;
+#endif
+
+  int MMFlags = MAP_PRIVATE |
+#ifdef HAVE_MMAP_ANONYMOUS
+  MAP_ANONYMOUS
+#else
+  MAP_ANON
+#endif
+  ; // Ends statement above
+
+  int Protect = getPosixProtectionFlags(PFlags);
+
+  // 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;
+  if (Start && Start % PageSize)
+    Start += PageSize - Start % PageSize;
+
+  void *Addr = ::mmap(reinterpret_cast<void*>(Start), PageSize*NumPages,
+                      Protect, MMFlags, fd, 0);
+  if (Addr == MAP_FAILED) {
+    if (NearBlock) //Try again without a near hint
+      return allocateMappedMemory(NumBytes, 0, PFlags, EC);
+
+    EC = error_code(errno, system_category());
+    return MemoryBlock();
+  }
+
+  MemoryBlock Result;
+  Result.Address = Addr;
+  Result.Size = NumPages*PageSize;
+
+  if (PFlags & MF_EXEC)
+    Memory::InvalidateInstructionCache(Result.Address, Result.Size);
+
+  return Result;
+}
+
+error_code
+Memory::releaseMappedMemory(MemoryBlock &M) {
+  if (M.Address == 0 || M.Size == 0)
+    return error_code::success();
+
+  if (0 != ::munmap(M.Address, M.Size))
+    return error_code(errno, system_category());
+
+  M.Address = 0;
+  M.Size = 0;
+
+  return error_code::success();
+}
+
+error_code
+Memory::protectMappedMemory(const MemoryBlock &M, unsigned Flags) {
+  if (M.Address == 0 || M.Size == 0)
+    return error_code::success();
+
+  if (!Flags)
+    return error_code(EINVAL, generic_category());
+
+  int Protect = getPosixProtectionFlags(Flags);
+
+  int Result = ::mprotect(M.Address, M.Size, Protect);
+  if (Result != 0)
+    return error_code(errno, system_category());
+
+  if (Flags & MF_EXEC)
+    Memory::InvalidateInstructionCache(M.Address, M.Size);
+
+  return error_code::success();
+}
+
 /// AllocateRWX - Allocate a slab of memory with read/write/execute
 /// permissions.  This is typically used for JIT applications where we want
 /// to emit code to the memory then jump to it.  Getting this type of memory
 /// is very OS specific.
 ///
-llvm::sys::MemoryBlock
-llvm::sys::Memory::AllocateRWX(size_t NumBytes, const MemoryBlock* NearBlock,
-                               std::string *ErrMsg) {
+MemoryBlock
+Memory::AllocateRWX(size_t NumBytes, const MemoryBlock* NearBlock,
+                    std::string *ErrMsg) {
   if (NumBytes == 0) return MemoryBlock();
 
   size_t pageSize = Process::GetPageSize();
@@ -86,7 +211,7 @@ llvm::sys::Memory::AllocateRWX(size_t NumBytes, const MemoryBlock* NearBlock,
                                 VM_PROT_READ | VM_PROT_EXECUTE | VM_PROT_COPY);
   if (KERN_SUCCESS != kr) {
     MakeErrMsg(ErrMsg, "vm_protect max RX failed");
-    return sys::MemoryBlock();
+    return MemoryBlock();
   }
 
   kr = vm_protect(mach_task_self(), (vm_address_t)pa,
@@ -94,7 +219,7 @@ llvm::sys::Memory::AllocateRWX(size_t NumBytes, const MemoryBlock* NearBlock,
                   VM_PROT_READ | VM_PROT_WRITE);
   if (KERN_SUCCESS != kr) {
     MakeErrMsg(ErrMsg, "vm_protect RW failed");
-    return sys::MemoryBlock();
+    return MemoryBlock();
   }
 #endif
 
@@ -105,17 +230,17 @@ llvm::sys::Memory::AllocateRWX(size_t NumBytes, const MemoryBlock* NearBlock,
   return result;
 }
 
-bool llvm::sys::Memory::ReleaseRWX(MemoryBlock &M, std::string *ErrMsg) {
+bool Memory::ReleaseRWX(MemoryBlock &M, std::string *ErrMsg) {
   if (M.Address == 0 || M.Size == 0) return false;
   if (0 != ::munmap(M.Address, M.Size))
     return MakeErrMsg(ErrMsg, "Can't release RWX Memory");
   return false;
 }
 
-bool llvm::sys::Memory::setWritable (MemoryBlock &M, std::string *ErrMsg) {
+bool Memory::setWritable (MemoryBlock &M, std::string *ErrMsg) {
 #if defined(__APPLE__) && defined(__arm__)
   if (M.Address == 0 || M.Size == 0) return false;
-  sys::Memory::InvalidateInstructionCache(M.Address, M.Size);
+  Memory::InvalidateInstructionCache(M.Address, M.Size);
   kern_return_t kr = vm_protect(mach_task_self(), (vm_address_t)M.Address,
     (vm_size_t)M.Size, 0, VM_PROT_READ | VM_PROT_WRITE);
   return KERN_SUCCESS == kr;
@@ -124,10 +249,10 @@ bool llvm::sys::Memory::setWritable (MemoryBlock &M, std::string *ErrMsg) {
 #endif
 }
 
-bool llvm::sys::Memory::setExecutable (MemoryBlock &M, std::string *ErrMsg) {
+bool Memory::setExecutable (MemoryBlock &M, std::string *ErrMsg) {
 #if defined(__APPLE__) && defined(__arm__)
   if (M.Address == 0 || M.Size == 0) return false;
-  sys::Memory::InvalidateInstructionCache(M.Address, M.Size);
+  Memory::InvalidateInstructionCache(M.Address, M.Size);
   kern_return_t kr = vm_protect(mach_task_self(), (vm_address_t)M.Address,
     (vm_size_t)M.Size, 0, VM_PROT_READ | VM_PROT_EXECUTE | VM_PROT_COPY);
   return KERN_SUCCESS == kr;
@@ -136,7 +261,7 @@ bool llvm::sys::Memory::setExecutable (MemoryBlock &M, std::string *ErrMsg) {
 #endif
 }
 
-bool llvm::sys::Memory::setRangeWritable(const void *Addr, size_t Size) {
+bool Memory::setRangeWritable(const void *Addr, size_t Size) {
 #if defined(__APPLE__) && defined(__arm__)
   kern_return_t kr = vm_protect(mach_task_self(), (vm_address_t)Addr,
                                 (vm_size_t)Size, 0,
@@ -147,7 +272,7 @@ bool llvm::sys::Memory::setRangeWritable(const void *Addr, size_t Size) {
 #endif
 }
 
-bool llvm::sys::Memory::setRangeExecutable(const void *Addr, size_t Size) {
+bool Memory::setRangeExecutable(const void *Addr, size_t Size) {
 #if defined(__APPLE__) && defined(__arm__)
   kern_return_t kr = vm_protect(mach_task_self(), (vm_address_t)Addr,
                                 (vm_size_t)Size, 0,
@@ -157,3 +282,52 @@ bool llvm::sys::Memory::setRangeExecutable(const void *Addr, size_t Size) {
   return true;
 #endif
 }
+
+/// InvalidateInstructionCache - Before the JIT can run a block of code
+/// that has been emitted it must invalidate the instruction cache on some
+/// platforms.
+void Memory::InvalidateInstructionCache(const void *Addr,
+                                        size_t Len) {
+
+// icache invalidation for PPC and ARM.
+#if defined(__APPLE__)
+
+#  if (defined(__POWERPC__) || defined (__ppc__) || \
+     defined(_POWER) || defined(_ARCH_PPC)) || defined(__arm__)
+  sys_icache_invalidate(const_cast<void *>(Addr), Len);
+#  endif
+
+#else
+
+#  if (defined(__POWERPC__) || defined (__ppc__) || \
+       defined(_POWER) || defined(_ARCH_PPC)) && defined(__GNUC__)
+  const size_t LineSize = 32;
+
+  const intptr_t Mask = ~(LineSize - 1);
+  const intptr_t StartLine = ((intptr_t) Addr) & Mask;
+  const intptr_t EndLine = ((intptr_t) Addr + Len + LineSize - 1) & Mask;
+
+  for (intptr_t Line = StartLine; Line < EndLine; Line += LineSize)
+    asm volatile("dcbf 0, %0" : : "r"(Line));
+  asm volatile("sync");
+
+  for (intptr_t Line = StartLine; Line < EndLine; Line += LineSize)
+    asm volatile("icbi 0, %0" : : "r"(Line));
+  asm volatile("isync");
+#  elif defined(__arm__) && defined(__GNUC__)
+  // FIXME: Can we safely always call this for __GNUC__ everywhere?
+  const char *Start = static_cast<const char *>(Addr);
+  const char *End = Start + Len;
+  __clear_cache(const_cast<char *>(Start), const_cast<char *>(End));
+#  elif defined(__mips__)
+  const char *Start = static_cast<const char *>(Addr);
+  cacheflush(const_cast<char *>(Start), Len, BCACHE);
+#  endif
+
+#endif  // end apple
+
+  ValgrindDiscardTranslations(Addr, Len);
+}
+
+} // namespace sys
+} // namespace llvm
diff --git a/lib/Support/Windows/Memory.inc b/lib/Support/Windows/Memory.inc
index fcc7283..cb80f28 100644
--- a/lib/Support/Windows/Memory.inc
+++ b/lib/Support/Windows/Memory.inc
@@ -12,51 +12,163 @@
 //
 //===----------------------------------------------------------------------===//
 
-#include "Windows.h"
 #include "llvm/Support/DataTypes.h"
+#include "llvm/Support/ErrorHandling.h"
 #include "llvm/Support/Process.h"
+#include "Windows.h"
+
+namespace {
+
+DWORD getWindowsProtectionFlags(unsigned Flags) {
+  switch (Flags) {
+  // Contrary to what you might expect, the Windows page protection flags
+  // are not a bitwise combination of RWX values
+  case llvm::sys::Memory::MF_READ:
+    return PAGE_READONLY;
+  case llvm::sys::Memory::MF_WRITE:
+    // Note: PAGE_WRITE is not supported by VirtualProtect
+    return PAGE_READWRITE;
+  case llvm::sys::Memory::MF_READ|llvm::sys::Memory::MF_WRITE:
+    return PAGE_READWRITE;
+  case llvm::sys::Memory::MF_READ|llvm::sys::Memory::MF_EXEC:
+    return PAGE_EXECUTE_READ;
+  case llvm::sys::Memory::MF_READ |
+         llvm::sys::Memory::MF_WRITE |
+         llvm::sys::Memory::MF_EXEC:
+    return PAGE_EXECUTE_READWRITE;
+  case llvm::sys::Memory::MF_EXEC:
+    return PAGE_EXECUTE;
+  default:
+    llvm_unreachable("Illegal memory protection flag specified!");
+  }
+  // Provide a default return value as required by some compilers.
+  return PAGE_NOACCESS;
+}
+
+size_t getAllocationGranularity() {
+  SYSTEM_INFO  Info;
+  ::GetSystemInfo(&Info);
+  if (Info.dwPageSize > Info.dwAllocationGranularity)
+    return Info.dwPageSize;
+  else
+    return Info.dwAllocationGranularity;
+}
+
+} // namespace
 
 namespace llvm {
-using namespace sys;
+namespace sys {
 
 //===----------------------------------------------------------------------===//
 //=== WARNING: Implementation here must contain only Win32 specific code
 //===          and must not be UNIX code
 //===----------------------------------------------------------------------===//
 
-MemoryBlock Memory::AllocateRWX(size_t NumBytes,
-                                const MemoryBlock *NearBlock,
-                                std::string *ErrMsg) {
-  if (NumBytes == 0) return MemoryBlock();
+MemoryBlock Memory::allocateMappedMemory(size_t NumBytes,
+                                         const MemoryBlock *const NearBlock,
+                                         unsigned Flags,
+                                         error_code &EC) {
+  EC = error_code::success();
+  if (NumBytes == 0)
+    return MemoryBlock();
+
+  // While we'd be happy to allocate single pages, the Windows allocation
+  // granularity may be larger than a single page (in practice, it is 64K)
+  // so mapping less than that will create an unreachable fragment of memory.
+  static const size_t Granularity = getAllocationGranularity();
+  const size_t NumBlocks = (NumBytes+Granularity-1)/Granularity;
 
-  static const size_t pageSize = Process::GetPageSize();
-  size_t NumPages = (NumBytes+pageSize-1)/pageSize;
+  uintptr_t Start = NearBlock ? reinterpret_cast<uintptr_t>(NearBlock->base()) +
+                                NearBlock->size()
+                           : NULL;
 
-  PVOID start = NearBlock ? static_cast<unsigned char *>(NearBlock->base()) +
-                                NearBlock->size() : NULL;
+  // If the requested address is not aligned to the allocation granularity,
+  // round up to get beyond NearBlock. VirtualAlloc would have rounded down.
+  if (Start && Start % Granularity != 0)
+    Start += Granularity - Start % Granularity;
 
-  void *pa = VirtualAlloc(start, NumPages*pageSize, MEM_RESERVE | MEM_COMMIT,
-                  PAGE_EXECUTE_READWRITE);
-  if (pa == NULL) {
+  DWORD Protect = getWindowsProtectionFlags(Flags);
+
+  void *PA = ::VirtualAlloc(reinterpret_cast<void*>(Start),
+                            NumBlocks*Granularity,
+                            MEM_RESERVE | MEM_COMMIT, Protect);
+  if (PA == NULL) {
     if (NearBlock) {
       // Try again without the NearBlock hint
-      return AllocateRWX(NumBytes, NULL, ErrMsg);
+      return allocateMappedMemory(NumBytes, NULL, Flags, EC);
     }
-    MakeErrMsg(ErrMsg, "Can't allocate RWX Memory: ");
+    EC = error_code(::GetLastError(), system_category());
     return MemoryBlock();
   }
 
-  MemoryBlock result;
-  result.Address = pa;
-  result.Size = NumPages*pageSize;
-  return result;
+  MemoryBlock Result;
+  Result.Address = PA;
+  Result.Size = NumBlocks*Granularity;
+                                 ;
+  if (Flags & MF_EXEC)
+    Memory::InvalidateInstructionCache(Result.Address, Result.Size);
+
+  return Result;
 }
 
-bool Memory::ReleaseRWX(MemoryBlock &M, std::string *ErrMsg) {
-  if (M.Address == 0 || M.Size == 0) return false;
+error_code Memory::releaseMappedMemory(MemoryBlock &M) {
+  if (M.Address == 0 || M.Size == 0)
+    return error_code::success();
+
   if (!VirtualFree(M.Address, 0, MEM_RELEASE))
-    return MakeErrMsg(ErrMsg, "Can't release RWX Memory: ");
-  return false;
+    return error_code(::GetLastError(), system_category());
+
+  M.Address = 0;
+  M.Size = 0;
+
+  return error_code::success();
+}
+
+error_code Memory::protectMappedMemory(const MemoryBlock &M,
+                                       unsigned Flags) {
+  if (M.Address == 0 || M.Size == 0)
+    return error_code::success();
+
+  DWORD Protect = getWindowsProtectionFlags(Flags);
+
+  DWORD OldFlags;
+  if (!VirtualProtect(M.Address, M.Size, Protect, &OldFlags))
+    return error_code(::GetLastError(), system_category());
+
+  if (Flags & MF_EXEC)
+    Memory::InvalidateInstructionCache(M.Address, M.Size);
+
+  return error_code::success();
+}
+
+/// InvalidateInstructionCache - Before the JIT can run a block of code
+/// that has been emitted it must invalidate the instruction cache on some
+/// platforms.
+void Memory::InvalidateInstructionCache(
+    const void *Addr, size_t Len) {
+  FlushInstructionCache(GetCurrentProcess(), Addr, Len);
+}
+
+
+MemoryBlock Memory::AllocateRWX(size_t NumBytes,
+                                const MemoryBlock *NearBlock,
+                                std::string *ErrMsg) {
+  MemoryBlock MB;
+  error_code EC;
+  MB = allocateMappedMemory(NumBytes, NearBlock,
+                            MF_READ|MF_WRITE|MF_EXEC, EC);
+  if (EC != error_code::success() && ErrMsg) {
+    MakeErrMsg(ErrMsg, EC.message());
+  }
+  return MB;
+}
+
+bool Memory::ReleaseRWX(MemoryBlock &M, std::string *ErrMsg) {
+  error_code EC = releaseMappedMemory(M);
+  if (EC == error_code::success())
+    return false;
+  MakeErrMsg(ErrMsg, EC.message());
+  return true;
 }
 
 static DWORD getProtection(const void *addr) {
@@ -93,7 +205,7 @@ bool Memory::setRangeWritable(const void *Addr, size_t Size) {
   }
 
   DWORD oldProt;
-  sys::Memory::InvalidateInstructionCache(Addr, Size);
+  Memory::InvalidateInstructionCache(Addr, Size);
   return ::VirtualProtect(const_cast<LPVOID>(Addr), Size, prot, &oldProt)
             == TRUE;
 }
@@ -112,9 +224,10 @@ bool Memory::setRangeExecutable(const void *Addr, size_t Size) {
   }
 
   DWORD oldProt;
-  sys::Memory::InvalidateInstructionCache(Addr, Size);
+  Memory::InvalidateInstructionCache(Addr, Size);
   return ::VirtualProtect(const_cast<LPVOID>(Addr), Size, prot, &oldProt)
             == TRUE;
 }
 
-}
+} // namespace sys
+} // namespace llvm