1 //===-- RTDyldMemoryManager.cpp - Memory manager for MC-JIT -----*- C++ -*-===// 2 // 3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions. 4 // See https://llvm.org/LICENSE.txt for license information. 5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception 6 // 7 //===----------------------------------------------------------------------===// 8 // 9 // Implementation of the runtime dynamic memory manager base class. 10 // 11 //===----------------------------------------------------------------------===// 12 13 #include "llvm/Config/config.h" 14 #include "llvm/ExecutionEngine/RTDyldMemoryManager.h" 15 #include "llvm/Support/Compiler.h" 16 #include "llvm/Support/DynamicLibrary.h" 17 #include "llvm/Support/ErrorHandling.h" 18 #include <cstdlib> 19 20 #ifdef __linux__ 21 // These includes used by RTDyldMemoryManager::getPointerToNamedFunction() 22 // for Glibc trickery. See comments in this function for more information. 23 #ifdef HAVE_SYS_STAT_H 24 #include <sys/stat.h> 25 #endif 26 #include <fcntl.h> 27 #include <unistd.h> 28 #endif 29 30 namespace llvm { 31 32 RTDyldMemoryManager::~RTDyldMemoryManager() {} 33 34 // Determine whether we can register EH tables. 35 #if (defined(__GNUC__) && !defined(__ARM_EABI__) && !defined(__ia64__) && \ 36 !(defined(_AIX) && defined(__ibmxl__)) && !defined(__SEH__) && \ 37 !defined(__USING_SJLJ_EXCEPTIONS__)) 38 #define HAVE_EHTABLE_SUPPORT 1 39 #else 40 #define HAVE_EHTABLE_SUPPORT 0 41 #endif 42 43 #if HAVE_EHTABLE_SUPPORT 44 extern "C" void __register_frame(void *); 45 extern "C" void __deregister_frame(void *); 46 #else 47 // The building compiler does not have __(de)register_frame but 48 // it may be found at runtime in a dynamically-loaded library. 49 // For example, this happens when building LLVM with Visual C++ 50 // but using the MingW runtime. 51 static void __register_frame(void *p) { 52 static bool Searched = false; 53 static void((*rf)(void *)) = 0; 54 55 if (!Searched) { 56 Searched = true; 57 *(void **)&rf = 58 llvm::sys::DynamicLibrary::SearchForAddressOfSymbol("__register_frame"); 59 } 60 if (rf) 61 rf(p); 62 } 63 64 static void __deregister_frame(void *p) { 65 static bool Searched = false; 66 static void((*df)(void *)) = 0; 67 68 if (!Searched) { 69 Searched = true; 70 *(void **)&df = llvm::sys::DynamicLibrary::SearchForAddressOfSymbol( 71 "__deregister_frame"); 72 } 73 if (df) 74 df(p); 75 } 76 #endif 77 78 #ifdef __APPLE__ 79 80 static const char *processFDE(const char *Entry, bool isDeregister) { 81 const char *P = Entry; 82 uint32_t Length = *((const uint32_t *)P); 83 P += 4; 84 uint32_t Offset = *((const uint32_t *)P); 85 if (Offset != 0) { 86 if (isDeregister) 87 __deregister_frame(const_cast<char *>(Entry)); 88 else 89 __register_frame(const_cast<char *>(Entry)); 90 } 91 return P + Length; 92 } 93 94 // This implementation handles frame registration for local targets. 95 // Memory managers for remote targets should re-implement this function 96 // and use the LoadAddr parameter. 97 void RTDyldMemoryManager::registerEHFramesInProcess(uint8_t *Addr, 98 size_t Size) { 99 // On OS X OS X __register_frame takes a single FDE as an argument. 100 // See http://lists.llvm.org/pipermail/llvm-dev/2013-April/061737.html 101 // and projects/libunwind/src/UnwindLevel1-gcc-ext.c. 102 const char *P = (const char *)Addr; 103 const char *End = P + Size; 104 do { 105 P = processFDE(P, false); 106 } while(P != End); 107 } 108 109 void RTDyldMemoryManager::deregisterEHFramesInProcess(uint8_t *Addr, 110 size_t Size) { 111 const char *P = (const char *)Addr; 112 const char *End = P + Size; 113 do { 114 P = processFDE(P, true); 115 } while(P != End); 116 } 117 118 #else 119 120 void RTDyldMemoryManager::registerEHFramesInProcess(uint8_t *Addr, 121 size_t Size) { 122 // On Linux __register_frame takes a single argument: 123 // a pointer to the start of the .eh_frame section. 124 125 // How can it find the end? Because crtendS.o is linked 126 // in and it has an .eh_frame section with four zero chars. 127 __register_frame(Addr); 128 } 129 130 void RTDyldMemoryManager::deregisterEHFramesInProcess(uint8_t *Addr, 131 size_t Size) { 132 __deregister_frame(Addr); 133 } 134 135 #endif 136 137 void RTDyldMemoryManager::registerEHFrames(uint8_t *Addr, uint64_t LoadAddr, 138 size_t Size) { 139 registerEHFramesInProcess(Addr, Size); 140 EHFrames.push_back({Addr, Size}); 141 } 142 143 void RTDyldMemoryManager::deregisterEHFrames() { 144 for (auto &Frame : EHFrames) 145 deregisterEHFramesInProcess(Frame.Addr, Frame.Size); 146 EHFrames.clear(); 147 } 148 149 static int jit_noop() { 150 return 0; 151 } 152 153 // ARM math functions are statically linked on Android from libgcc.a, but not 154 // available at runtime for dynamic linking. On Linux these are usually placed 155 // in libgcc_s.so so can be found by normal dynamic lookup. 156 #if defined(__BIONIC__) && defined(__arm__) 157 // List of functions which are statically linked on Android and can be generated 158 // by LLVM. This is done as a nested macro which is used once to declare the 159 // imported functions with ARM_MATH_DECL and once to compare them to the 160 // user-requested symbol in getSymbolAddress with ARM_MATH_CHECK. The test 161 // assumes that all functions start with __aeabi_ and getSymbolAddress must be 162 // modified if that changes. 163 #define ARM_MATH_IMPORTS(PP) \ 164 PP(__aeabi_d2f) \ 165 PP(__aeabi_d2iz) \ 166 PP(__aeabi_d2lz) \ 167 PP(__aeabi_d2uiz) \ 168 PP(__aeabi_d2ulz) \ 169 PP(__aeabi_dadd) \ 170 PP(__aeabi_dcmpeq) \ 171 PP(__aeabi_dcmpge) \ 172 PP(__aeabi_dcmpgt) \ 173 PP(__aeabi_dcmple) \ 174 PP(__aeabi_dcmplt) \ 175 PP(__aeabi_dcmpun) \ 176 PP(__aeabi_ddiv) \ 177 PP(__aeabi_dmul) \ 178 PP(__aeabi_dsub) \ 179 PP(__aeabi_f2d) \ 180 PP(__aeabi_f2iz) \ 181 PP(__aeabi_f2lz) \ 182 PP(__aeabi_f2uiz) \ 183 PP(__aeabi_f2ulz) \ 184 PP(__aeabi_fadd) \ 185 PP(__aeabi_fcmpeq) \ 186 PP(__aeabi_fcmpge) \ 187 PP(__aeabi_fcmpgt) \ 188 PP(__aeabi_fcmple) \ 189 PP(__aeabi_fcmplt) \ 190 PP(__aeabi_fcmpun) \ 191 PP(__aeabi_fdiv) \ 192 PP(__aeabi_fmul) \ 193 PP(__aeabi_fsub) \ 194 PP(__aeabi_i2d) \ 195 PP(__aeabi_i2f) \ 196 PP(__aeabi_idiv) \ 197 PP(__aeabi_idivmod) \ 198 PP(__aeabi_l2d) \ 199 PP(__aeabi_l2f) \ 200 PP(__aeabi_lasr) \ 201 PP(__aeabi_ldivmod) \ 202 PP(__aeabi_llsl) \ 203 PP(__aeabi_llsr) \ 204 PP(__aeabi_lmul) \ 205 PP(__aeabi_ui2d) \ 206 PP(__aeabi_ui2f) \ 207 PP(__aeabi_uidiv) \ 208 PP(__aeabi_uidivmod) \ 209 PP(__aeabi_ul2d) \ 210 PP(__aeabi_ul2f) \ 211 PP(__aeabi_uldivmod) 212 213 // Declare statically linked math functions on ARM. The function declarations 214 // here do not have the correct prototypes for each function in 215 // ARM_MATH_IMPORTS, but it doesn't matter because only the symbol addresses are 216 // needed. In particular the __aeabi_*divmod functions do not have calling 217 // conventions which match any C prototype. 218 #define ARM_MATH_DECL(name) extern "C" void name(); 219 ARM_MATH_IMPORTS(ARM_MATH_DECL) 220 #undef ARM_MATH_DECL 221 #endif 222 223 #if defined(__linux__) && defined(__GLIBC__) && \ 224 (defined(__i386__) || defined(__x86_64__)) 225 extern "C" LLVM_ATTRIBUTE_WEAK void __morestack(); 226 #endif 227 228 uint64_t 229 RTDyldMemoryManager::getSymbolAddressInProcess(const std::string &Name) { 230 // This implementation assumes that the host program is the target. 231 // Clients generating code for a remote target should implement their own 232 // memory manager. 233 #if defined(__linux__) && defined(__GLIBC__) 234 //===--------------------------------------------------------------------===// 235 // Function stubs that are invoked instead of certain library calls 236 // 237 // Force the following functions to be linked in to anything that uses the 238 // JIT. This is a hack designed to work around the all-too-clever Glibc 239 // strategy of making these functions work differently when inlined vs. when 240 // not inlined, and hiding their real definitions in a separate archive file 241 // that the dynamic linker can't see. For more info, search for 242 // 'libc_nonshared.a' on Google, or read http://llvm.org/PR274. 243 if (Name == "stat") return (uint64_t)&stat; 244 if (Name == "fstat") return (uint64_t)&fstat; 245 if (Name == "lstat") return (uint64_t)&lstat; 246 if (Name == "stat64") return (uint64_t)&stat64; 247 if (Name == "fstat64") return (uint64_t)&fstat64; 248 if (Name == "lstat64") return (uint64_t)&lstat64; 249 if (Name == "atexit") return (uint64_t)&atexit; 250 if (Name == "mknod") return (uint64_t)&mknod; 251 252 #if defined(__i386__) || defined(__x86_64__) 253 // __morestack lives in libgcc, a static library. 254 if (&__morestack && Name == "__morestack") 255 return (uint64_t)&__morestack; 256 #endif 257 #endif // __linux__ && __GLIBC__ 258 259 // See ARM_MATH_IMPORTS definition for explanation 260 #if defined(__BIONIC__) && defined(__arm__) 261 if (Name.compare(0, 8, "__aeabi_") == 0) { 262 // Check if the user has requested any of the functions listed in 263 // ARM_MATH_IMPORTS, and if so redirect to the statically linked symbol. 264 #define ARM_MATH_CHECK(fn) if (Name == #fn) return (uint64_t)&fn; 265 ARM_MATH_IMPORTS(ARM_MATH_CHECK) 266 #undef ARM_MATH_CHECK 267 } 268 #endif 269 270 // We should not invoke parent's ctors/dtors from generated main()! 271 // On Mingw and Cygwin, the symbol __main is resolved to 272 // callee's(eg. tools/lli) one, to invoke wrong duplicated ctors 273 // (and register wrong callee's dtors with atexit(3)). 274 // We expect ExecutionEngine::runStaticConstructorsDestructors() 275 // is called before ExecutionEngine::runFunctionAsMain() is called. 276 if (Name == "__main") return (uint64_t)&jit_noop; 277 278 const char *NameStr = Name.c_str(); 279 280 // DynamicLibrary::SearchForAddresOfSymbol expects an unmangled 'C' symbol 281 // name so ff we're on Darwin, strip the leading '_' off. 282 #ifdef __APPLE__ 283 if (NameStr[0] == '_') 284 ++NameStr; 285 #endif 286 287 return (uint64_t)sys::DynamicLibrary::SearchForAddressOfSymbol(NameStr); 288 } 289 290 void *RTDyldMemoryManager::getPointerToNamedFunction(const std::string &Name, 291 bool AbortOnFailure) { 292 uint64_t Addr = getSymbolAddress(Name); 293 294 if (!Addr && AbortOnFailure) 295 report_fatal_error("Program used external function '" + Name + 296 "' which could not be resolved!"); 297 298 return (void*)Addr; 299 } 300 301 void RTDyldMemoryManager::anchor() {} 302 void MCJITMemoryManager::anchor() {} 303 } // namespace llvm 304