1 //===- Unix/Memory.cpp - Generic UNIX System Configuration ------*- C++ -*-===//
3 // The LLVM Compiler Infrastructure
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
8 //===----------------------------------------------------------------------===//
10 // This file defines some functions for various memory management utilities.
12 //===----------------------------------------------------------------------===//
15 #include "llvm/Support/DataTypes.h"
16 #include "llvm/Support/ErrorHandling.h"
17 #include "llvm/Support/Process.h"
19 #ifdef HAVE_SYS_MMAN_H
24 #include <mach/mach.h>
28 # if defined(__OpenBSD__)
29 # include <mips64/sysarch.h>
31 # include <sys/cachectl.h>
36 extern "C" void sys_icache_invalidate(const void *Addr, size_t len);
38 extern "C" void __clear_cache(void *, void*);
43 int getPosixProtectionFlags(unsigned Flags) {
45 case llvm::sys::Memory::MF_READ:
47 case llvm::sys::Memory::MF_WRITE:
49 case llvm::sys::Memory::MF_READ|llvm::sys::Memory::MF_WRITE:
50 return PROT_READ | PROT_WRITE;
51 case llvm::sys::Memory::MF_READ|llvm::sys::Memory::MF_EXEC:
52 return PROT_READ | PROT_EXEC;
53 case llvm::sys::Memory::MF_READ | llvm::sys::Memory::MF_WRITE |
54 llvm::sys::Memory::MF_EXEC:
55 return PROT_READ | PROT_WRITE | PROT_EXEC;
56 case llvm::sys::Memory::MF_EXEC:
57 #if defined(__FreeBSD__)
58 // On PowerPC, having an executable page that has no read permission
59 // can have unintended consequences. The function InvalidateInstruction-
60 // Cache uses instructions dcbf and icbi, both of which are treated by
61 // the processor as loads. If the page has no read permissions,
62 // executing these instructions will result in a segmentation fault.
63 // Somehow, this problem is not present on Linux, but it does happen
65 return PROT_READ | PROT_EXEC;
70 llvm_unreachable("Illegal memory protection flag specified!");
72 // Provide a default return value as required by some compilers.
76 } // anonymous namespace
82 Memory::allocateMappedMemory(size_t NumBytes,
83 const MemoryBlock *const NearBlock,
85 std::error_code &EC) {
86 EC = std::error_code();
90 static const size_t PageSize = Process::getPageSize();
91 const size_t NumPages = (NumBytes+PageSize-1)/PageSize;
94 #ifdef NEED_DEV_ZERO_FOR_MMAP
95 static int zero_fd = open("/dev/zero", O_RDWR);
97 EC = std::error_code(errno, std::generic_category());
103 int MMFlags = MAP_PRIVATE |
104 #ifdef HAVE_MMAP_ANONYMOUS
109 ; // Ends statement above
111 int Protect = getPosixProtectionFlags(PFlags);
113 // Use any near hint and the page size to set a page-aligned starting address
114 uintptr_t Start = NearBlock ? reinterpret_cast<uintptr_t>(NearBlock->base()) +
115 NearBlock->size() : 0;
116 if (Start && Start % PageSize)
117 Start += PageSize - Start % PageSize;
119 void *Addr = ::mmap(reinterpret_cast<void*>(Start), PageSize*NumPages,
120 Protect, MMFlags, fd, 0);
121 if (Addr == MAP_FAILED) {
122 if (NearBlock) //Try again without a near hint
123 return allocateMappedMemory(NumBytes, nullptr, PFlags, EC);
125 EC = std::error_code(errno, std::generic_category());
126 return MemoryBlock();
130 Result.Address = Addr;
131 Result.Size = NumPages*PageSize;
133 if (PFlags & MF_EXEC)
134 Memory::InvalidateInstructionCache(Result.Address, Result.Size);
140 Memory::releaseMappedMemory(MemoryBlock &M) {
141 if (M.Address == nullptr || M.Size == 0)
142 return std::error_code();
144 if (0 != ::munmap(M.Address, M.Size))
145 return std::error_code(errno, std::generic_category());
150 return std::error_code();
154 Memory::protectMappedMemory(const MemoryBlock &M, unsigned Flags) {
155 static const size_t PageSize = Process::getPageSize();
156 if (M.Address == nullptr || M.Size == 0)
157 return std::error_code();
160 return std::error_code(EINVAL, std::generic_category());
162 int Protect = getPosixProtectionFlags(Flags);
164 int Result = ::mprotect((void*)((uintptr_t)M.Address & ~(PageSize-1)), PageSize*((M.Size+PageSize-1)/PageSize), Protect);
166 return std::error_code(errno, std::generic_category());
169 Memory::InvalidateInstructionCache(M.Address, M.Size);
171 return std::error_code();
174 /// AllocateRWX - Allocate a slab of memory with read/write/execute
175 /// permissions. This is typically used for JIT applications where we want
176 /// to emit code to the memory then jump to it. Getting this type of memory
177 /// is very OS specific.
180 Memory::AllocateRWX(size_t NumBytes, const MemoryBlock* NearBlock,
181 std::string *ErrMsg) {
182 if (NumBytes == 0) return MemoryBlock();
184 static const size_t PageSize = Process::getPageSize();
185 size_t NumPages = (NumBytes+PageSize-1)/PageSize;
188 #ifdef NEED_DEV_ZERO_FOR_MMAP
189 static int zero_fd = open("/dev/zero", O_RDWR);
191 MakeErrMsg(ErrMsg, "Can't open /dev/zero device");
192 return MemoryBlock();
197 int flags = MAP_PRIVATE |
198 #ifdef HAVE_MMAP_ANONYMOUS
205 void* start = NearBlock ? (unsigned char*)NearBlock->base() +
206 NearBlock->size() : nullptr;
208 #if defined(__APPLE__) && (defined(__arm__) || defined(__arm64__))
209 void *pa = ::mmap(start, PageSize*NumPages, PROT_READ|PROT_EXEC,
212 void *pa = ::mmap(start, PageSize*NumPages, PROT_READ|PROT_WRITE|PROT_EXEC,
215 if (pa == MAP_FAILED) {
216 if (NearBlock) //Try again without a near hint
217 return AllocateRWX(NumBytes, nullptr);
219 MakeErrMsg(ErrMsg, "Can't allocate RWX Memory");
220 return MemoryBlock();
223 #if defined(__APPLE__) && (defined(__arm__) || defined(__arm64__))
224 kern_return_t kr = vm_protect(mach_task_self(), (vm_address_t)pa,
225 (vm_size_t)(PageSize*NumPages), 0,
226 VM_PROT_READ | VM_PROT_EXECUTE | VM_PROT_COPY);
227 if (KERN_SUCCESS != kr) {
228 MakeErrMsg(ErrMsg, "vm_protect max RX failed");
229 return MemoryBlock();
232 kr = vm_protect(mach_task_self(), (vm_address_t)pa,
233 (vm_size_t)(PageSize*NumPages), 0,
234 VM_PROT_READ | VM_PROT_WRITE);
235 if (KERN_SUCCESS != kr) {
236 MakeErrMsg(ErrMsg, "vm_protect RW failed");
237 return MemoryBlock();
243 result.Size = NumPages*PageSize;
248 bool Memory::ReleaseRWX(MemoryBlock &M, std::string *ErrMsg) {
249 if (M.Address == nullptr || M.Size == 0) return false;
250 if (0 != ::munmap(M.Address, M.Size))
251 return MakeErrMsg(ErrMsg, "Can't release RWX Memory");
255 bool Memory::setWritable (MemoryBlock &M, std::string *ErrMsg) {
256 #if defined(__APPLE__) && (defined(__arm__) || defined(__arm64__))
257 if (M.Address == 0 || M.Size == 0) return false;
258 Memory::InvalidateInstructionCache(M.Address, M.Size);
259 kern_return_t kr = vm_protect(mach_task_self(), (vm_address_t)M.Address,
260 (vm_size_t)M.Size, 0, VM_PROT_READ | VM_PROT_WRITE);
261 return KERN_SUCCESS == kr;
267 bool Memory::setExecutable (MemoryBlock &M, std::string *ErrMsg) {
268 if (M.Address == nullptr || M.Size == 0) return false;
269 Memory::InvalidateInstructionCache(M.Address, M.Size);
270 #if defined(__APPLE__) && (defined(__arm__) || defined(__arm64__))
271 kern_return_t kr = vm_protect(mach_task_self(), (vm_address_t)M.Address,
272 (vm_size_t)M.Size, 0, VM_PROT_READ | VM_PROT_EXECUTE | VM_PROT_COPY);
273 return KERN_SUCCESS == kr;
279 bool Memory::setRangeWritable(const void *Addr, size_t Size) {
280 #if defined(__APPLE__) && (defined(__arm__) || defined(__arm64__))
281 kern_return_t kr = vm_protect(mach_task_self(), (vm_address_t)Addr,
283 VM_PROT_READ | VM_PROT_WRITE);
284 return KERN_SUCCESS == kr;
290 bool Memory::setRangeExecutable(const void *Addr, size_t Size) {
291 #if defined(__APPLE__) && (defined(__arm__) || defined(__arm64__))
292 kern_return_t kr = vm_protect(mach_task_self(), (vm_address_t)Addr,
294 VM_PROT_READ | VM_PROT_EXECUTE | VM_PROT_COPY);
295 return KERN_SUCCESS == kr;
301 /// InvalidateInstructionCache - Before the JIT can run a block of code
302 /// that has been emitted it must invalidate the instruction cache on some
304 void Memory::InvalidateInstructionCache(const void *Addr,
307 // icache invalidation for PPC and ARM.
308 #if defined(__APPLE__)
310 # if (defined(__POWERPC__) || defined (__ppc__) || \
311 defined(_POWER) || defined(_ARCH_PPC) || defined(__arm__) || \
313 sys_icache_invalidate(const_cast<void *>(Addr), Len);
318 # if (defined(__POWERPC__) || defined (__ppc__) || \
319 defined(_POWER) || defined(_ARCH_PPC)) && defined(__GNUC__)
320 const size_t LineSize = 32;
322 const intptr_t Mask = ~(LineSize - 1);
323 const intptr_t StartLine = ((intptr_t) Addr) & Mask;
324 const intptr_t EndLine = ((intptr_t) Addr + Len + LineSize - 1) & Mask;
326 for (intptr_t Line = StartLine; Line < EndLine; Line += LineSize)
327 asm volatile("dcbf 0, %0" : : "r"(Line));
328 asm volatile("sync");
330 for (intptr_t Line = StartLine; Line < EndLine; Line += LineSize)
331 asm volatile("icbi 0, %0" : : "r"(Line));
332 asm volatile("isync");
333 # elif (defined(__arm__) || defined(__aarch64__) || defined(__mips__)) && \
335 // FIXME: Can we safely always call this for __GNUC__ everywhere?
336 const char *Start = static_cast<const char *>(Addr);
337 const char *End = Start + Len;
338 __clear_cache(const_cast<char *>(Start), const_cast<char *>(End));
343 ValgrindDiscardTranslations(Addr, Len);