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.
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 if (M.Address == nullptr || M.Size == 0)
156 return std::error_code();
159 return std::error_code(EINVAL, std::generic_category());
161 int Protect = getPosixProtectionFlags(Flags);
163 int Result = ::mprotect(M.Address, M.Size, Protect);
165 return std::error_code(errno, std::generic_category());
168 Memory::InvalidateInstructionCache(M.Address, M.Size);
170 return std::error_code();
173 /// AllocateRWX - Allocate a slab of memory with read/write/execute
174 /// permissions. This is typically used for JIT applications where we want
175 /// to emit code to the memory then jump to it. Getting this type of memory
176 /// is very OS specific.
179 Memory::AllocateRWX(size_t NumBytes, const MemoryBlock* NearBlock,
180 std::string *ErrMsg) {
181 if (NumBytes == 0) return MemoryBlock();
183 size_t PageSize = Process::getPageSize();
184 size_t NumPages = (NumBytes+PageSize-1)/PageSize;
187 #ifdef NEED_DEV_ZERO_FOR_MMAP
188 static int zero_fd = open("/dev/zero", O_RDWR);
190 MakeErrMsg(ErrMsg, "Can't open /dev/zero device");
191 return MemoryBlock();
196 int flags = MAP_PRIVATE |
197 #ifdef HAVE_MMAP_ANONYMOUS
204 void* start = NearBlock ? (unsigned char*)NearBlock->base() +
205 NearBlock->size() : nullptr;
207 #if defined(__APPLE__) && (defined(__arm__) || defined(__arm64__))
208 void *pa = ::mmap(start, PageSize*NumPages, PROT_READ|PROT_EXEC,
211 void *pa = ::mmap(start, PageSize*NumPages, PROT_READ|PROT_WRITE|PROT_EXEC,
214 if (pa == MAP_FAILED) {
215 if (NearBlock) //Try again without a near hint
216 return AllocateRWX(NumBytes, nullptr);
218 MakeErrMsg(ErrMsg, "Can't allocate RWX Memory");
219 return MemoryBlock();
222 #if defined(__APPLE__) && (defined(__arm__) || defined(__arm64__))
223 kern_return_t kr = vm_protect(mach_task_self(), (vm_address_t)pa,
224 (vm_size_t)(PageSize*NumPages), 0,
225 VM_PROT_READ | VM_PROT_EXECUTE | VM_PROT_COPY);
226 if (KERN_SUCCESS != kr) {
227 MakeErrMsg(ErrMsg, "vm_protect max RX failed");
228 return MemoryBlock();
231 kr = vm_protect(mach_task_self(), (vm_address_t)pa,
232 (vm_size_t)(PageSize*NumPages), 0,
233 VM_PROT_READ | VM_PROT_WRITE);
234 if (KERN_SUCCESS != kr) {
235 MakeErrMsg(ErrMsg, "vm_protect RW failed");
236 return MemoryBlock();
242 result.Size = NumPages*PageSize;
247 bool Memory::ReleaseRWX(MemoryBlock &M, std::string *ErrMsg) {
248 if (M.Address == nullptr || M.Size == 0) return false;
249 if (0 != ::munmap(M.Address, M.Size))
250 return MakeErrMsg(ErrMsg, "Can't release RWX Memory");
254 bool Memory::setWritable (MemoryBlock &M, std::string *ErrMsg) {
255 #if defined(__APPLE__) && (defined(__arm__) || defined(__arm64__))
256 if (M.Address == 0 || M.Size == 0) return false;
257 Memory::InvalidateInstructionCache(M.Address, M.Size);
258 kern_return_t kr = vm_protect(mach_task_self(), (vm_address_t)M.Address,
259 (vm_size_t)M.Size, 0, VM_PROT_READ | VM_PROT_WRITE);
260 return KERN_SUCCESS == kr;
266 bool Memory::setExecutable (MemoryBlock &M, std::string *ErrMsg) {
267 #if defined(__APPLE__) && (defined(__arm__) || defined(__arm64__))
268 if (M.Address == 0 || M.Size == 0) return false;
269 Memory::InvalidateInstructionCache(M.Address, M.Size);
270 kern_return_t kr = vm_protect(mach_task_self(), (vm_address_t)M.Address,
271 (vm_size_t)M.Size, 0, VM_PROT_READ | VM_PROT_EXECUTE | VM_PROT_COPY);
272 return KERN_SUCCESS == kr;
273 #elif defined(__arm__) || defined(__aarch64__)
274 Memory::InvalidateInstructionCache(M.Address, M.Size);
281 bool Memory::setRangeWritable(const void *Addr, size_t Size) {
282 #if defined(__APPLE__) && (defined(__arm__) || defined(__arm64__))
283 kern_return_t kr = vm_protect(mach_task_self(), (vm_address_t)Addr,
285 VM_PROT_READ | VM_PROT_WRITE);
286 return KERN_SUCCESS == kr;
292 bool Memory::setRangeExecutable(const void *Addr, size_t Size) {
293 #if defined(__APPLE__) && (defined(__arm__) || defined(__arm64__))
294 kern_return_t kr = vm_protect(mach_task_self(), (vm_address_t)Addr,
296 VM_PROT_READ | VM_PROT_EXECUTE | VM_PROT_COPY);
297 return KERN_SUCCESS == kr;
303 /// InvalidateInstructionCache - Before the JIT can run a block of code
304 /// that has been emitted it must invalidate the instruction cache on some
306 void Memory::InvalidateInstructionCache(const void *Addr,
309 // icache invalidation for PPC and ARM.
310 #if defined(__APPLE__)
312 # if (defined(__POWERPC__) || defined (__ppc__) || \
313 defined(_POWER) || defined(_ARCH_PPC) || defined(__arm__) || \
315 sys_icache_invalidate(const_cast<void *>(Addr), Len);
320 # if (defined(__POWERPC__) || defined (__ppc__) || \
321 defined(_POWER) || defined(_ARCH_PPC)) && defined(__GNUC__)
322 const size_t LineSize = 32;
324 const intptr_t Mask = ~(LineSize - 1);
325 const intptr_t StartLine = ((intptr_t) Addr) & Mask;
326 const intptr_t EndLine = ((intptr_t) Addr + Len + LineSize - 1) & Mask;
328 for (intptr_t Line = StartLine; Line < EndLine; Line += LineSize)
329 asm volatile("dcbf 0, %0" : : "r"(Line));
330 asm volatile("sync");
332 for (intptr_t Line = StartLine; Line < EndLine; Line += LineSize)
333 asm volatile("icbi 0, %0" : : "r"(Line));
334 asm volatile("isync");
335 # elif (defined(__arm__) || defined(__aarch64__) || defined(__mips__)) && \
337 // FIXME: Can we safely always call this for __GNUC__ everywhere?
338 const char *Start = static_cast<const char *>(Addr);
339 const char *End = Start + Len;
340 __clear_cache(const_cast<char *>(Start), const_cast<char *>(End));
345 ValgrindDiscardTranslations(Addr, Len);