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.inline.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 "runtime/arguments.hpp" 39 #include "runtime/handles.inline.hpp" 40 #include "runtime/javaCalls.hpp" 41 #include "runtime/sharedRuntime.hpp" 42 #include "runtime/signature.hpp" 43 #include "utilities/macros.hpp" 44 #ifdef TARGET_OS_FAMILY_linux 45 # include "os_linux.inline.hpp" 46 #endif 47 #ifdef TARGET_OS_FAMILY_solaris 48 # include "os_solaris.inline.hpp" 49 #endif 50 #ifdef TARGET_OS_FAMILY_windows 51 # include "os_windows.inline.hpp" 52 #endif 53 #ifdef TARGET_OS_FAMILY_aix 54 # include "os_aix.inline.hpp" 55 #endif 56 #ifdef TARGET_OS_FAMILY_bsd 57 # include "os_bsd.inline.hpp" 58 #endif 59 60 61 static void mangle_name_on(outputStream* st, Symbol* name, int begin, int end) { 62 char* bytes = (char*)name->bytes() + begin; 63 char* end_bytes = (char*)name->bytes() + end; 64 while (bytes < end_bytes) { 65 jchar c; 66 bytes = UTF8::next(bytes, &c); 67 if (c <= 0x7f && isalnum(c)) { 68 st->put((char) c); 69 } else { 70 if (c == '_') st->print("_1"); 71 else if (c == '/') st->print("_"); 72 else if (c == ';') st->print("_2"); 73 else if (c == '[') st->print("_3"); 74 else st->print("_%.5x", c); 75 } 76 } 77 } 78 79 80 static void mangle_name_on(outputStream* st, Symbol* name) { 81 mangle_name_on(st, name, 0, name->utf8_length()); 82 } 83 84 85 char* NativeLookup::pure_jni_name(methodHandle method) { 86 stringStream st; 87 // Prefix 88 st.print("Java_"); 89 // Klass name 90 mangle_name_on(&st, method->klass_name()); 91 st.print("_"); 92 // Method name 93 mangle_name_on(&st, method->name()); 94 return st.as_string(); 95 } 96 97 98 char* NativeLookup::critical_jni_name(methodHandle method) { 99 stringStream st; 100 // Prefix 101 st.print("JavaCritical_"); 102 // Klass name 103 mangle_name_on(&st, method->klass_name()); 104 st.print("_"); 105 // Method name 106 mangle_name_on(&st, method->name()); 107 return st.as_string(); 108 } 109 110 111 char* NativeLookup::long_jni_name(methodHandle method) { 112 // Signature ignore the wrapping parenteses and the trailing return type 113 stringStream st; 114 Symbol* signature = method->signature(); 115 st.print("__"); 116 // find ')' 117 int end; 118 for (end = 0; end < signature->utf8_length() && signature->byte_at(end) != ')'; end++); 119 // skip first '(' 120 mangle_name_on(&st, signature, 1, end); 121 return st.as_string(); 122 } 123 124 extern "C" { 125 void JNICALL JVM_RegisterUnsafeMethods(JNIEnv *env, jclass unsafecls); 126 void JNICALL JVM_RegisterMethodHandleMethods(JNIEnv *env, jclass unsafecls); 127 void JNICALL JVM_RegisterPerfMethods(JNIEnv *env, jclass perfclass); 128 void JNICALL JVM_RegisterWhiteBoxMethods(JNIEnv *env, jclass wbclass); 129 } 130 131 #define CC (char*) /* cast a literal from (const char*) */ 132 #define FN_PTR(f) CAST_FROM_FN_PTR(void*, &f) 133 134 static JNINativeMethod lookup_special_native_methods[] = { 135 { CC"Java_sun_misc_Unsafe_registerNatives", NULL, FN_PTR(JVM_RegisterUnsafeMethods) }, 136 { CC"Java_java_lang_invoke_MethodHandleNatives_registerNatives", NULL, FN_PTR(JVM_RegisterMethodHandleMethods) }, 137 { CC"Java_sun_misc_Perf_registerNatives", NULL, FN_PTR(JVM_RegisterPerfMethods) }, 138 { CC"Java_sun_hotspot_WhiteBox_registerNatives", NULL, FN_PTR(JVM_RegisterWhiteBoxMethods) }, 139 }; 140 141 static address lookup_special_native(char* jni_name) { 142 int count = sizeof(lookup_special_native_methods) / sizeof(JNINativeMethod); 143 for (int i = 0; i < count; i++) { 144 // NB: To ignore the jni prefix and jni postfix strstr is used matching. 145 if (strstr(jni_name, lookup_special_native_methods[i].name) != NULL) { 146 return CAST_FROM_FN_PTR(address, lookup_special_native_methods[i].fnPtr); 147 } 148 } 149 return NULL; 150 } 151 152 address NativeLookup::lookup_style(methodHandle method, char* pure_name, const char* long_name, int args_size, bool os_style, bool& in_base_library, TRAPS) { 153 address entry; 154 // Compute complete JNI name for style 155 stringStream st; 156 if (os_style) os::print_jni_name_prefix_on(&st, args_size); 157 st.print_raw(pure_name); 158 st.print_raw(long_name); 159 if (os_style) os::print_jni_name_suffix_on(&st, args_size); 160 char* jni_name = st.as_string(); 161 162 // If the loader is null we have a system class, so we attempt a lookup in 163 // the native Java library. This takes care of any bootstrapping problems. 164 // Note: It is critical for bootstrapping that Java_java_lang_ClassLoader_00024NativeLibrary_find 165 // gets found the first time around - otherwise an infinite loop can occure. This is 166 // another VM/library dependency 167 Handle loader(THREAD, method->method_holder()->class_loader()); 168 if (loader.is_null()) { 169 entry = lookup_special_native(jni_name); 170 if (entry == NULL) { 171 entry = (address) os::dll_lookup(os::native_java_library(), jni_name); 172 } 173 if (entry != NULL) { 174 in_base_library = true; 175 return entry; 176 } 177 } 178 179 // Otherwise call static method findNative in ClassLoader 180 KlassHandle klass (THREAD, SystemDictionary::ClassLoader_klass()); 181 Handle name_arg = java_lang_String::create_from_str(jni_name, CHECK_NULL); 182 183 JavaValue result(T_LONG); 184 JavaCalls::call_static(&result, 185 klass, 186 vmSymbols::findNative_name(), 187 vmSymbols::classloader_string_long_signature(), 188 // Arguments 189 loader, 190 name_arg, 191 CHECK_NULL); 192 entry = (address) (intptr_t) result.get_jlong(); 193 194 if (entry == NULL) { 195 // findNative didn't find it, if there are any agent libraries look in them 196 AgentLibrary* agent; 197 for (agent = Arguments::agents(); agent != NULL; agent = agent->next()) { 198 entry = (address) os::dll_lookup(agent->os_lib(), jni_name); 199 if (entry != NULL) { 200 return entry; 201 } 202 } 203 } 204 205 return entry; 206 } 207 208 209 address NativeLookup::lookup_critical_style(methodHandle method, char* pure_name, const char* long_name, int args_size, bool os_style) { 210 if (!method->has_native_function()) { 211 return NULL; 212 } 213 214 address current_entry = method->native_function(); 215 216 char dll_name[JVM_MAXPATHLEN]; 217 int offset; 218 if (os::dll_address_to_library_name(current_entry, dll_name, sizeof(dll_name), &offset)) { 219 char ebuf[32]; 220 void* dll = os::dll_load(dll_name, ebuf, sizeof(ebuf)); 221 if (dll != NULL) { 222 // Compute complete JNI name for style 223 stringStream st; 224 if (os_style) os::print_jni_name_prefix_on(&st, args_size); 225 st.print_raw(pure_name); 226 st.print_raw(long_name); 227 if (os_style) os::print_jni_name_suffix_on(&st, args_size); 228 char* jni_name = st.as_string(); 229 return (address)os::dll_lookup(dll, jni_name); 230 } 231 } 232 233 return NULL; 234 } 235 236 237 // Check all the formats of native implementation name to see if there is one 238 // for the specified method. 239 address NativeLookup::lookup_entry(methodHandle method, bool& in_base_library, TRAPS) { 240 address entry = NULL; 241 in_base_library = false; 242 // Compute pure name 243 char* pure_name = pure_jni_name(method); 244 245 // Compute argument size 246 int args_size = 1 // JNIEnv 247 + (method->is_static() ? 1 : 0) // class for static methods 248 + method->size_of_parameters(); // actual parameters 249 250 251 // 1) Try JNI short style 252 entry = lookup_style(method, pure_name, "", args_size, true, in_base_library, CHECK_NULL); 253 if (entry != NULL) return entry; 254 255 // Compute long name 256 char* long_name = long_jni_name(method); 257 258 // 2) Try JNI long style 259 entry = lookup_style(method, pure_name, long_name, args_size, true, in_base_library, CHECK_NULL); 260 if (entry != NULL) return entry; 261 262 // 3) Try JNI short style without os prefix/suffix 263 entry = lookup_style(method, pure_name, "", args_size, false, in_base_library, CHECK_NULL); 264 if (entry != NULL) return entry; 265 266 // 4) Try JNI long style without os prefix/suffix 267 entry = lookup_style(method, pure_name, long_name, args_size, false, in_base_library, CHECK_NULL); 268 269 return entry; // NULL indicates not found 270 } 271 272 // Check all the formats of native implementation name to see if there is one 273 // for the specified method. 274 address NativeLookup::lookup_critical_entry(methodHandle method) { 275 if (!CriticalJNINatives) return NULL; 276 277 if (method->is_synchronized() || 278 !method->is_static()) { 279 // Only static non-synchronized methods are allowed 280 return NULL; 281 } 282 283 ResourceMark rm; 284 address entry = NULL; 285 286 Symbol* signature = method->signature(); 287 for (int end = 0; end < signature->utf8_length(); end++) { 288 if (signature->byte_at(end) == 'L') { 289 // Don't allow object types 290 return NULL; 291 } 292 } 293 294 // Compute critical name 295 char* critical_name = critical_jni_name(method); 296 297 // Compute argument size 298 int args_size = 1 // JNIEnv 299 + (method->is_static() ? 1 : 0) // class for static methods 300 + method->size_of_parameters(); // actual parameters 301 302 303 // 1) Try JNI short style 304 entry = lookup_critical_style(method, critical_name, "", args_size, true); 305 if (entry != NULL) return entry; 306 307 // Compute long name 308 char* long_name = long_jni_name(method); 309 310 // 2) Try JNI long style 311 entry = lookup_critical_style(method, critical_name, long_name, args_size, true); 312 if (entry != NULL) return entry; 313 314 // 3) Try JNI short style without os prefix/suffix 315 entry = lookup_critical_style(method, critical_name, "", args_size, false); 316 if (entry != NULL) return entry; 317 318 // 4) Try JNI long style without os prefix/suffix 319 entry = lookup_critical_style(method, critical_name, long_name, args_size, false); 320 321 return entry; // NULL indicates not found 322 } 323 324 // Check if there are any JVM TI prefixes which have been applied to the native method name. 325 // If any are found, remove them before attemping the look up of the 326 // native implementation again. 327 // See SetNativeMethodPrefix in the JVM TI Spec for more details. 328 address NativeLookup::lookup_entry_prefixed(methodHandle method, bool& in_base_library, TRAPS) { 329 #if INCLUDE_JVMTI 330 ResourceMark rm(THREAD); 331 332 int prefix_count; 333 char** prefixes = JvmtiExport::get_all_native_method_prefixes(&prefix_count); 334 char* in_name = method->name()->as_C_string(); 335 char* wrapper_name = in_name; 336 // last applied prefix will be first -- go backwards 337 for (int i = prefix_count-1; i >= 0; i--) { 338 char* prefix = prefixes[i]; 339 size_t prefix_len = strlen(prefix); 340 if (strncmp(prefix, wrapper_name, prefix_len) == 0) { 341 // has this prefix remove it 342 wrapper_name += prefix_len; 343 } 344 } 345 if (wrapper_name != in_name) { 346 // we have a name for a wrapping method 347 int wrapper_name_len = (int)strlen(wrapper_name); 348 TempNewSymbol wrapper_symbol = SymbolTable::probe(wrapper_name, wrapper_name_len); 349 if (wrapper_symbol != NULL) { 350 KlassHandle kh(method->method_holder()); 351 Method* wrapper_method = kh()->lookup_method(wrapper_symbol, 352 method->signature()); 353 if (wrapper_method != NULL && !wrapper_method->is_native()) { 354 // we found a wrapper method, use its native entry 355 method->set_is_prefixed_native(); 356 return lookup_entry(wrapper_method, in_base_library, THREAD); 357 } 358 } 359 } 360 #endif // INCLUDE_JVMTI 361 return NULL; 362 } 363 364 address NativeLookup::lookup_base(methodHandle method, bool& in_base_library, TRAPS) { 365 address entry = NULL; 366 ResourceMark rm(THREAD); 367 368 entry = lookup_entry(method, in_base_library, THREAD); 369 if (entry != NULL) return entry; 370 371 // standard native method resolution has failed. Check if there are any 372 // JVM TI prefixes which have been applied to the native method name. 373 entry = lookup_entry_prefixed(method, in_base_library, THREAD); 374 if (entry != NULL) return entry; 375 376 // Native function not found, throw UnsatisfiedLinkError 377 THROW_MSG_0(vmSymbols::java_lang_UnsatisfiedLinkError(), 378 method->name_and_sig_as_C_string()); 379 } 380 381 382 address NativeLookup::lookup(methodHandle method, bool& in_base_library, TRAPS) { 383 if (!method->has_native_function()) { 384 address entry = lookup_base(method, in_base_library, CHECK_NULL); 385 method->set_native_function(entry, 386 Method::native_bind_event_is_interesting); 387 // -verbose:jni printing 388 if (PrintJNIResolving) { 389 ResourceMark rm(THREAD); 390 tty->print_cr("[Dynamic-linking native method %s.%s ... JNI]", 391 method->method_holder()->external_name(), 392 method->name()->as_C_string()); 393 } 394 } 395 return method->native_function(); 396 } 397 398 address NativeLookup::base_library_lookup(const char* class_name, const char* method_name, const char* signature) { 399 EXCEPTION_MARK; 400 bool in_base_library = true; // SharedRuntime inits some math methods. 401 TempNewSymbol c_name = SymbolTable::new_symbol(class_name, CATCH); 402 TempNewSymbol m_name = SymbolTable::new_symbol(method_name, CATCH); 403 TempNewSymbol s_name = SymbolTable::new_symbol(signature, CATCH); 404 405 // Find the class 406 Klass* k = SystemDictionary::resolve_or_fail(c_name, true, CATCH); 407 instanceKlassHandle klass (THREAD, k); 408 409 // Find method and invoke standard lookup 410 methodHandle method (THREAD, 411 klass->uncached_lookup_method(m_name, s_name, Klass::find_overpass)); 412 address result = lookup(method, in_base_library, CATCH); 413 assert(in_base_library, "must be in basic library"); 414 guarantee(result != NULL, "must be non NULL"); 415 return result; 416 }