lib/ExecutionEngine/RuntimeDyld/RTDyldMemoryManager.cpp

   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