1 /* 2 * Copyright (c) 1997, 2017, Oracle and/or its affiliates. All rights reserved. 3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. 4 * 5 * This code is free software; you can redistribute it and/or modify it 6 * under the terms of the GNU General Public License version 2 only, as 7 * published by the Free Software Foundation. 8 * 9 * This code is distributed in the hope that it will be useful, but WITHOUT 10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or 11 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License 12 * version 2 for more details (a copy is included in the LICENSE file that 13 * accompanied this code). 14 * 15 * You should have received a copy of the GNU General Public License version 16 * 2 along with this work; if not, write to the Free Software Foundation, 17 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. 18 * 19 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA 20 * or visit www.oracle.com if you need additional information or have any 21 * questions. 22 * 23 */ 24 25 #include "precompiled.hpp" 26 #include "classfile/javaClasses.hpp" 27 #include "classfile/systemDictionary.hpp" 28 #include "classfile/vmSymbols.hpp" 29 #include "memory/oopFactory.hpp" 30 #include "memory/resourceArea.hpp" 31 #include "memory/universe.hpp" 32 #include "oops/instanceKlass.hpp" 33 #include "oops/method.hpp" 34 #include "oops/oop.inline.hpp" 35 #include "oops/symbol.hpp" 36 #include "prims/jvm_misc.hpp" 37 #include "prims/nativeLookup.hpp" 38 #include "prims/unsafe.hpp" 39 #include "runtime/arguments.hpp" 40 #include "runtime/handles.inline.hpp" 41 #include "runtime/javaCalls.hpp" 42 #include "runtime/sharedRuntime.hpp" 43 #include "runtime/signature.hpp" 44 #include "utilities/macros.hpp" 45 #if INCLUDE_TRACE 46 #include "trace/traceMacros.hpp" 47 #endif 48 49 static void mangle_name_on(outputStream* st, Symbol* name, int begin, int end) { 50 char* bytes = (char*)name->bytes() + begin; 51 char* end_bytes = (char*)name->bytes() + end; 52 while (bytes < end_bytes) { 53 jchar c; 54 bytes = UTF8::next(bytes, &c); 55 if (c <= 0x7f && isalnum(c)) { 56 st->put((char) c); 57 } else { 58 if (c == '_') st->print("_1"); 59 else if (c == '/') st->print("_"); 60 else if (c == ';') st->print("_2"); 61 else if (c == '[') st->print("_3"); 62 else st->print("_%.5x", c); 63 } 64 } 65 } 66 67 68 static void mangle_name_on(outputStream* st, Symbol* name) { 69 mangle_name_on(st, name, 0, name->utf8_length()); 70 } 71 72 73 char* NativeLookup::pure_jni_name(const methodHandle& method) { 74 stringStream st; 75 // Prefix 76 st.print("Java_"); 77 // Klass name 78 mangle_name_on(&st, method->klass_name()); 79 st.print("_"); 80 // Method name 81 mangle_name_on(&st, method->name()); 82 return st.as_string(); 83 } 84 85 86 char* NativeLookup::critical_jni_name(const methodHandle& method) { 87 stringStream st; 88 // Prefix 89 st.print("JavaCritical_"); 90 // Klass name 91 mangle_name_on(&st, method->klass_name()); 92 st.print("_"); 93 // Method name 94 mangle_name_on(&st, method->name()); 95 return st.as_string(); 96 } 97 98 99 char* NativeLookup::long_jni_name(const methodHandle& method) { 100 // Signature ignore the wrapping parenteses and the trailing return type 101 stringStream st; 102 Symbol* signature = method->signature(); 103 st.print("__"); 104 // find ')' 105 int end; 106 for (end = 0; end < signature->utf8_length() && signature->byte_at(end) != ')'; end++); 107 // skip first '(' 108 mangle_name_on(&st, signature, 1, end); 109 return st.as_string(); 110 } 111 112 extern "C" { 113 void JNICALL JVM_RegisterMethodHandleMethods(JNIEnv *env, jclass unsafecls); 114 void JNICALL JVM_RegisterPerfMethods(JNIEnv *env, jclass perfclass); 115 void JNICALL JVM_RegisterWhiteBoxMethods(JNIEnv *env, jclass wbclass); 116 #if INCLUDE_JVMCI 117 jobject JNICALL JVM_GetJVMCIRuntime(JNIEnv *env, jclass c); 118 void JNICALL JVM_RegisterJVMCINatives(JNIEnv *env, jclass compilerToVMClass); 119 #endif 120 } 121 122 #define CC (char*) /* cast a literal from (const char*) */ 123 #define FN_PTR(f) CAST_FROM_FN_PTR(void*, &f) 124 125 static JNINativeMethod lookup_special_native_methods[] = { 126 { CC"Java_jdk_internal_misc_Unsafe_registerNatives", NULL, FN_PTR(JVM_RegisterJDKInternalMiscUnsafeMethods) }, 127 { CC"Java_java_lang_invoke_MethodHandleNatives_registerNatives", NULL, FN_PTR(JVM_RegisterMethodHandleMethods) }, 128 { CC"Java_jdk_internal_perf_Perf_registerNatives", NULL, FN_PTR(JVM_RegisterPerfMethods) }, 129 { CC"Java_sun_hotspot_WhiteBox_registerNatives", NULL, FN_PTR(JVM_RegisterWhiteBoxMethods) }, 130 #if INCLUDE_JVMCI 131 { CC"Java_jdk_vm_ci_runtime_JVMCI_initializeRuntime", NULL, FN_PTR(JVM_GetJVMCIRuntime) }, 132 { CC"Java_jdk_vm_ci_hotspot_CompilerToVM_registerNatives", NULL, FN_PTR(JVM_RegisterJVMCINatives) }, 133 #endif 134 #if INCLUDE_TRACE 135 { CC"Java_jdk_jfr_internal_JVM_registerNatives", NULL, TRACE_REGISTER_NATIVES }, 136 #endif 137 }; 138 139 static address lookup_special_native(char* jni_name) { 140 int count = sizeof(lookup_special_native_methods) / sizeof(JNINativeMethod); 141 for (int i = 0; i < count; i++) { 142 // NB: To ignore the jni prefix and jni postfix strstr is used matching. 143 if (strstr(jni_name, lookup_special_native_methods[i].name) != NULL) { 144 return CAST_FROM_FN_PTR(address, lookup_special_native_methods[i].fnPtr); 145 } 146 } 147 return NULL; 148 } 149 150 address NativeLookup::lookup_style(const methodHandle& method, char* pure_name, const char* long_name, int args_size, bool os_style, bool& in_base_library, TRAPS) { 151 address entry; 152 // Compute complete JNI name for style 153 stringStream st; 154 if (os_style) os::print_jni_name_prefix_on(&st, args_size); 155 st.print_raw(pure_name); 156 st.print_raw(long_name); 157 if (os_style) os::print_jni_name_suffix_on(&st, args_size); 158 char* jni_name = st.as_string(); 159 160 // If the loader is null we have a system class, so we attempt a lookup in 161 // the native Java library. This takes care of any bootstrapping problems. 162 // Note: It is critical for bootstrapping that Java_java_lang_ClassLoader_00024NativeLibrary_find 163 // gets found the first time around - otherwise an infinite loop can occure. This is 164 // another VM/library dependency 165 Handle loader(THREAD, method->method_holder()->class_loader()); 166 if (loader.is_null()) { 167 entry = lookup_special_native(jni_name); 168 if (entry == NULL) { 169 entry = (address) os::dll_lookup(os::native_java_library(), jni_name); 170 } 171 if (entry != NULL) { 172 in_base_library = true; 173 return entry; 174 } 175 } 176 177 // Otherwise call static method findNative in ClassLoader 178 Klass* klass = SystemDictionary::ClassLoader_klass(); 179 Handle name_arg = java_lang_String::create_from_str(jni_name, CHECK_NULL); 180 181 JavaValue result(T_LONG); 182 JavaCalls::call_static(&result, 183 klass, 184 vmSymbols::findNative_name(), 185 vmSymbols::classloader_string_long_signature(), 186 // Arguments 187 loader, 188 name_arg, 189 CHECK_NULL); 190 entry = (address) (intptr_t) result.get_jlong(); 191 192 if (entry == NULL) { 193 // findNative didn't find it, if there are any agent libraries look in them 194 AgentLibrary* agent; 195 for (agent = Arguments::agents(); agent != NULL; agent = agent->next()) { 196 entry = (address) os::dll_lookup(agent->os_lib(), jni_name); 197 if (entry != NULL) { 198 return entry; 199 } 200 } 201 } 202 203 return entry; 204 } 205 206 207 address NativeLookup::lookup_critical_style(const methodHandle& method, char* pure_name, const char* long_name, int args_size, bool os_style) { 208 if (!method->has_native_function()) { 209 return NULL; 210 } 211 212 address current_entry = method->native_function(); 213 214 char dll_name[JVM_MAXPATHLEN]; 215 int offset; 216 if (os::dll_address_to_library_name(current_entry, dll_name, sizeof(dll_name), &offset)) { 217 char ebuf[32]; 218 void* dll = os::dll_load(dll_name, ebuf, sizeof(ebuf)); 219 if (dll != NULL) { 220 // Compute complete JNI name for style 221 stringStream st; 222 if (os_style) os::print_jni_name_prefix_on(&st, args_size); 223 st.print_raw(pure_name); 224 st.print_raw(long_name); 225 if (os_style) os::print_jni_name_suffix_on(&st, args_size); 226 char* jni_name = st.as_string(); 227 address critical_entry = (address)os::dll_lookup(dll, jni_name); 228 // Close the handle to avoid keeping the library alive if the native method holder is unloaded. 229 // This is fine because the library is still kept alive by JNI (see JVM_LoadLibrary). As soon 230 // as the holder class and the library are unloaded (see JVM_UnloadLibrary), the native wrapper 231 // that calls 'critical_entry' becomes unreachable and is unloaded as well. 232 os::dll_unload(dll); 233 return critical_entry; 234 } 235 } 236 237 return NULL; 238 } 239 240 241 // Check all the formats of native implementation name to see if there is one 242 // for the specified method. 243 address NativeLookup::lookup_entry(const methodHandle& method, bool& in_base_library, TRAPS) { 244 address entry = NULL; 245 in_base_library = false; 246 // Compute pure name 247 char* pure_name = pure_jni_name(method); 248 249 // Compute argument size 250 int args_size = 1 // JNIEnv 251 + (method->is_static() ? 1 : 0) // class for static methods 252 + method->size_of_parameters(); // actual parameters 253 254 // 1) Try JNI short style 255 entry = lookup_style(method, pure_name, "", args_size, true, in_base_library, CHECK_NULL); 256 if (entry != NULL) return entry; 257 258 // Compute long name 259 char* long_name = long_jni_name(method); 260 261 // 2) Try JNI long style 262 entry = lookup_style(method, pure_name, long_name, args_size, true, in_base_library, CHECK_NULL); 263 if (entry != NULL) return entry; 264 265 // 3) Try JNI short style without os prefix/suffix 266 entry = lookup_style(method, pure_name, "", args_size, false, in_base_library, CHECK_NULL); 267 if (entry != NULL) return entry; 268 269 // 4) Try JNI long style without os prefix/suffix 270 entry = lookup_style(method, pure_name, long_name, args_size, false, in_base_library, CHECK_NULL); 271 272 return entry; // NULL indicates not found 273 } 274 275 // Check all the formats of native implementation name to see if there is one 276 // for the specified method. 277 address NativeLookup::lookup_critical_entry(const methodHandle& method) { 278 if (!CriticalJNINatives) return NULL; 279 280 if (method->is_synchronized() || 281 !method->is_static()) { 282 // Only static non-synchronized methods are allowed 283 return NULL; 284 } 285 286 ResourceMark rm; 287 address entry = NULL; 288 289 Symbol* signature = method->signature(); 290 for (int end = 0; end < signature->utf8_length(); end++) { 291 if (signature->byte_at(end) == 'L') { 292 // Don't allow object types 293 return NULL; 294 } 295 } 296 297 // Compute critical name 298 char* critical_name = critical_jni_name(method); 299 300 // Compute argument size 301 int args_size = method->size_of_parameters(); 302 for (SignatureStream ss(signature); !ss.at_return_type(); ss.next()) { 303 if (ss.is_array()) { 304 args_size += T_INT_size; // array length parameter 305 } 306 } 307 308 // 1) Try JNI short style 309 entry = lookup_critical_style(method, critical_name, "", args_size, true); 310 if (entry != NULL) return entry; 311 312 // Compute long name 313 char* long_name = long_jni_name(method); 314 315 // 2) Try JNI long style 316 entry = lookup_critical_style(method, critical_name, long_name, args_size, true); 317 if (entry != NULL) return entry; 318 319 // 3) Try JNI short style without os prefix/suffix 320 entry = lookup_critical_style(method, critical_name, "", args_size, false); 321 if (entry != NULL) return entry; 322 323 // 4) Try JNI long style without os prefix/suffix 324 entry = lookup_critical_style(method, critical_name, long_name, args_size, false); 325 326 return entry; // NULL indicates not found 327 } 328 329 // Check if there are any JVM TI prefixes which have been applied to the native method name. 330 // If any are found, remove them before attemping the look up of the 331 // native implementation again. 332 // See SetNativeMethodPrefix in the JVM TI Spec for more details. 333 address NativeLookup::lookup_entry_prefixed(const methodHandle& method, bool& in_base_library, TRAPS) { 334 #if INCLUDE_JVMTI 335 ResourceMark rm(THREAD); 336 337 int prefix_count; 338 char** prefixes = JvmtiExport::get_all_native_method_prefixes(&prefix_count); 339 char* in_name = method->name()->as_C_string(); 340 char* wrapper_name = in_name; 341 // last applied prefix will be first -- go backwards 342 for (int i = prefix_count-1; i >= 0; i--) { 343 char* prefix = prefixes[i]; 344 size_t prefix_len = strlen(prefix); 345 if (strncmp(prefix, wrapper_name, prefix_len) == 0) { 346 // has this prefix remove it 347 wrapper_name += prefix_len; 348 } 349 } 350 if (wrapper_name != in_name) { 351 // we have a name for a wrapping method 352 int wrapper_name_len = (int)strlen(wrapper_name); 353 TempNewSymbol wrapper_symbol = SymbolTable::probe(wrapper_name, wrapper_name_len); 354 if (wrapper_symbol != NULL) { 355 Klass* k = method->method_holder(); 356 Method* wrapper_method = k->lookup_method(wrapper_symbol, method->signature()); 357 if (wrapper_method != NULL && !wrapper_method->is_native()) { 358 // we found a wrapper method, use its native entry 359 method->set_is_prefixed_native(); 360 return lookup_entry(wrapper_method, in_base_library, THREAD); 361 } 362 } 363 } 364 #endif // INCLUDE_JVMTI 365 return NULL; 366 } 367 368 address NativeLookup::lookup_base(const methodHandle& method, bool& in_base_library, TRAPS) { 369 address entry = NULL; 370 ResourceMark rm(THREAD); 371 372 entry = lookup_entry(method, in_base_library, THREAD); 373 if (entry != NULL) return entry; 374 375 // standard native method resolution has failed. Check if there are any 376 // JVM TI prefixes which have been applied to the native method name. 377 entry = lookup_entry_prefixed(method, in_base_library, THREAD); 378 if (entry != NULL) return entry; 379 380 // Native function not found, throw UnsatisfiedLinkError 381 THROW_MSG_0(vmSymbols::java_lang_UnsatisfiedLinkError(), 382 method->name_and_sig_as_C_string()); 383 } 384 385 386 address NativeLookup::lookup(const methodHandle& method, bool& in_base_library, TRAPS) { 387 if (!method->has_native_function()) { 388 address entry = lookup_base(method, in_base_library, CHECK_NULL); 389 method->set_native_function(entry, 390 Method::native_bind_event_is_interesting); 391 // -verbose:jni printing 392 if (PrintJNIResolving) { 393 ResourceMark rm(THREAD); 394 tty->print_cr("[Dynamic-linking native method %s.%s ... JNI]", 395 method->method_holder()->external_name(), 396 method->name()->as_C_string()); 397 } 398 } 399 return method->native_function(); 400 } 401 402 address NativeLookup::base_library_lookup(const char* class_name, const char* method_name, const char* signature) { 403 EXCEPTION_MARK; 404 bool in_base_library = true; // SharedRuntime inits some math methods. 405 TempNewSymbol c_name = SymbolTable::new_symbol(class_name, CATCH); 406 TempNewSymbol m_name = SymbolTable::new_symbol(method_name, CATCH); 407 TempNewSymbol s_name = SymbolTable::new_symbol(signature, CATCH); 408 409 // Find the class 410 Klass* k = SystemDictionary::resolve_or_fail(c_name, true, CATCH); 411 InstanceKlass* klass = InstanceKlass::cast(k); 412 413 // Find method and invoke standard lookup 414 methodHandle method (THREAD, 415 klass->uncached_lookup_method(m_name, s_name, Klass::find_overpass)); 416 address result = lookup(method, in_base_library, CATCH); 417 assert(in_base_library, "must be in basic library"); 418 guarantee(result != NULL, "must be non NULL"); 419 return result; 420 }