[Support] Support NetBSD PaX MPROTECT in sys::Memory.
Removes AllocateRWX, setWritable and setExecutable from sys::Memory and
standardizes on allocateMappedMemory / protectMappedMemory. The
allocateMappedMemory method is updated to request full permissions for memory
blocks so that they can be marked executable later.
llvm-svn: 318464
diff --git a/llvm/lib/Support/Unix/Memory.inc b/llvm/lib/Support/Unix/Memory.inc
index cf812d0..3148016 100644
--- a/llvm/lib/Support/Unix/Memory.inc
+++ b/llvm/lib/Support/Unix/Memory.inc
@@ -102,6 +102,10 @@
int Protect = getPosixProtectionFlags(PFlags);
+#if defined(__NetBSD__) && defined(PROT_MPROTECT)
+ Protect |= PROT_MPROTECT(PROT_READ | PROT_WRITE | PROT_EXEC);
+#endif
+
// 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;
@@ -166,129 +170,6 @@
return std::error_code();
}
-/// 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.
-///
-MemoryBlock
-Memory::AllocateRWX(size_t NumBytes, const MemoryBlock* NearBlock,
- std::string *ErrMsg) {
- if (NumBytes == 0) return MemoryBlock();
-
- static const size_t PageSize = Process::getPageSize();
- size_t NumPages = (NumBytes+PageSize-1)/PageSize;
-
- int fd = -1;
-
- int flags = MAP_PRIVATE |
-#ifdef MAP_ANONYMOUS
- MAP_ANONYMOUS
-#else
- MAP_ANON
-#endif
- ;
-
- void* start = NearBlock ? (unsigned char*)NearBlock->base() +
- NearBlock->size() : nullptr;
-
-#if defined(__APPLE__) && (defined(__arm__) || defined(__arm64__))
- void *pa = ::mmap(start, PageSize*NumPages, PROT_READ|PROT_EXEC,
- flags, fd, 0);
-#elif defined(__NetBSD__) && defined(PROT_MPROTECT)
- void *pa =
- ::mmap(start, PageSize * NumPages,
- PROT_READ | PROT_WRITE | PROT_MPROTECT(PROT_EXEC), flags, fd, 0);
-#else
- void *pa = ::mmap(start, PageSize*NumPages, PROT_READ|PROT_WRITE|PROT_EXEC,
- flags, fd, 0);
-#endif
- if (pa == MAP_FAILED) {
- if (NearBlock) //Try again without a near hint
- return AllocateRWX(NumBytes, nullptr);
-
- MakeErrMsg(ErrMsg, "Can't allocate RWX Memory");
- return MemoryBlock();
- }
-
-#if defined(__APPLE__) && (defined(__arm__) || defined(__arm64__))
- kern_return_t kr = vm_protect(mach_task_self(), (vm_address_t)pa,
- (vm_size_t)(PageSize*NumPages), 0,
- VM_PROT_READ | VM_PROT_EXECUTE | VM_PROT_COPY);
- if (KERN_SUCCESS != kr) {
- MakeErrMsg(ErrMsg, "vm_protect max RX failed");
- return MemoryBlock();
- }
-
- kr = vm_protect(mach_task_self(), (vm_address_t)pa,
- (vm_size_t)(PageSize*NumPages), 0,
- VM_PROT_READ | VM_PROT_WRITE);
- if (KERN_SUCCESS != kr) {
- MakeErrMsg(ErrMsg, "vm_protect RW failed");
- return MemoryBlock();
- }
-#endif
-
- MemoryBlock result;
- result.Address = pa;
- result.Size = NumPages*PageSize;
-
- return result;
-}
-
-bool Memory::ReleaseRWX(MemoryBlock &M, std::string *ErrMsg) {
- if (M.Address == nullptr || M.Size == 0) return false;
- if (0 != ::munmap(M.Address, M.Size))
- return MakeErrMsg(ErrMsg, "Can't release RWX Memory");
- return false;
-}
-
-bool Memory::setWritable (MemoryBlock &M, std::string *ErrMsg) {
-#if defined(__APPLE__) && (defined(__arm__) || defined(__arm64__))
- if (M.Address == 0 || M.Size == 0) return false;
- 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;
-#else
- return true;
-#endif
-}
-
-bool Memory::setExecutable (MemoryBlock &M, std::string *ErrMsg) {
- if (M.Address == nullptr || M.Size == 0) return false;
- Memory::InvalidateInstructionCache(M.Address, M.Size);
-#if defined(__APPLE__) && (defined(__arm__) || defined(__arm64__))
- 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;
-#else
- return true;
-#endif
-}
-
-bool Memory::setRangeWritable(const void *Addr, size_t Size) {
-#if defined(__APPLE__) && (defined(__arm__) || defined(__arm64__))
- kern_return_t kr = vm_protect(mach_task_self(), (vm_address_t)Addr,
- (vm_size_t)Size, 0,
- VM_PROT_READ | VM_PROT_WRITE);
- return KERN_SUCCESS == kr;
-#else
- return true;
-#endif
-}
-
-bool Memory::setRangeExecutable(const void *Addr, size_t Size) {
-#if defined(__APPLE__) && (defined(__arm__) || defined(__arm64__))
- kern_return_t kr = vm_protect(mach_task_self(), (vm_address_t)Addr,
- (vm_size_t)Size, 0,
- VM_PROT_READ | VM_PROT_EXECUTE | VM_PROT_COPY);
- return KERN_SUCCESS == kr;
-#else
- 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.