1 /* 2 * Copyright (c) 1997, 2011, 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/methodOop.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 #ifdef TARGET_OS_FAMILY_linux 44 # include "os_linux.inline.hpp" 45 #endif 46 #ifdef TARGET_OS_FAMILY_solaris 47 # include "os_solaris.inline.hpp" 48 #endif 49 #ifdef TARGET_OS_FAMILY_windows 50 # include "os_windows.inline.hpp" 51 #endif 52 #ifdef TARGET_OS_FAMILY_bsd 53 # include "os_bsd.inline.hpp" 54 #endif 55 56 57 static void mangle_name_on(outputStream* st, Symbol* name, int begin, int end) { 58 char* bytes = (char*)name->bytes() + begin; 59 char* end_bytes = (char*)name->bytes() + end; 60 while (bytes < end_bytes) { 61 jchar c; 62 bytes = UTF8::next(bytes, &c); 63 if (c <= 0x7f && isalnum(c)) { 64 st->put((char) c); 65 } else { 66 if (c == '_') st->print("_1"); 67 else if (c == '/') st->print("_"); 68 else if (c == ';') st->print("_2"); 69 else if (c == '[') st->print("_3"); 70 else st->print("_%.5x", c); 71 } 72 } 73 } 74 75 76 static void mangle_name_on(outputStream* st, Symbol* name) { 77 mangle_name_on(st, name, 0, name->utf8_length()); 78 } 79 80 81 char* NativeLookup::pure_jni_name(methodHandle method) { 82 stringStream st; 83 // Prefix 84 st.print("Java_"); 85 // Klass name 86 mangle_name_on(&st, method->klass_name()); 87 st.print("_"); 88 // Method name 89 mangle_name_on(&st, method->name()); 90 return st.as_string(); 91 } 92 93 94 char* NativeLookup::long_jni_name(methodHandle method) { 95 // Signature ignore the wrapping parenteses and the trailing return type 96 stringStream st; 97 Symbol* signature = method->signature(); 98 st.print("__"); 99 // find ')' 100 int end; 101 for (end = 0; end < signature->utf8_length() && signature->byte_at(end) != ')'; end++); 102 // skip first '(' 103 mangle_name_on(&st, signature, 1, end); 104 return st.as_string(); 105 } 106 107 extern "C" { 108 void JNICALL JVM_RegisterUnsafeMethods(JNIEnv *env, jclass unsafecls); 109 void JNICALL JVM_RegisterMethodHandleMethods(JNIEnv *env, jclass unsafecls); 110 void JNICALL JVM_RegisterPerfMethods(JNIEnv *env, jclass perfclass); 111 } 112 113 #define CC (char*) /* cast a literal from (const char*) */ 114 #define FN_PTR(f) CAST_FROM_FN_PTR(void*, &f) 115 116 static JNINativeMethod lookup_special_native_methods[] = { 117 // Next two functions only exist for compatibility with 1.3.1 and earlier. 118 { CC"Java_java_io_ObjectOutputStream_getPrimitiveFieldValues", NULL, FN_PTR(JVM_GetPrimitiveFieldValues) }, // intercept ObjectOutputStream getPrimitiveFieldValues for faster serialization 119 { CC"Java_java_io_ObjectInputStream_setPrimitiveFieldValues", NULL, FN_PTR(JVM_SetPrimitiveFieldValues) }, // intercept ObjectInputStream setPrimitiveFieldValues for faster serialization 120 121 { CC"Java_sun_misc_Unsafe_registerNatives", NULL, FN_PTR(JVM_RegisterUnsafeMethods) }, 122 { CC"Java_java_lang_invoke_MethodHandleNatives_registerNatives", NULL, FN_PTR(JVM_RegisterMethodHandleMethods) }, 123 { CC"Java_sun_misc_Perf_registerNatives", NULL, FN_PTR(JVM_RegisterPerfMethods) } 124 }; 125 126 static address lookup_special_native(char* jni_name) { 127 int i = !JDK_Version::is_gte_jdk14x_version() ? 0 : 2; // see comment in lookup_special_native_methods 128 int count = sizeof(lookup_special_native_methods) / sizeof(JNINativeMethod); 129 for (; i < count; i++) { 130 // NB: To ignore the jni prefix and jni postfix strstr is used matching. 131 if (strstr(jni_name, lookup_special_native_methods[i].name) != NULL) { 132 return CAST_FROM_FN_PTR(address, lookup_special_native_methods[i].fnPtr); 133 } 134 } 135 return NULL; 136 } 137 138 address NativeLookup::lookup_style(methodHandle method, char* pure_name, const char* long_name, int args_size, bool os_style, bool& in_base_library, TRAPS) { 139 address entry; 140 // Compute complete JNI name for style 141 stringStream st; 142 if (os_style) os::print_jni_name_prefix_on(&st, args_size); 143 st.print_raw(pure_name); 144 st.print_raw(long_name); 145 if (os_style) os::print_jni_name_suffix_on(&st, args_size); 146 char* jni_name = st.as_string(); 147 148 // If the loader is null we have a system class, so we attempt a lookup in 149 // the native Java library. This takes care of any bootstrapping problems. 150 // Note: It is critical for bootstrapping that Java_java_lang_ClassLoader_00024NativeLibrary_find 151 // gets found the first time around - otherwise an infinite loop can occure. This is 152 // another VM/library dependency 153 Handle loader(THREAD, 154 instanceKlass::cast(method->method_holder())->class_loader()); 155 if (loader.is_null()) { 156 entry = lookup_special_native(jni_name); 157 if (entry == NULL) { 158 entry = (address) os::dll_lookup(os::native_java_library(), jni_name); 159 } 160 if (entry != NULL) { 161 in_base_library = true; 162 return entry; 163 } 164 } 165 166 // Otherwise call static method findNative in ClassLoader 167 KlassHandle klass (THREAD, SystemDictionary::ClassLoader_klass()); 168 Handle name_arg = java_lang_String::create_from_str(jni_name, CHECK_NULL); 169 170 JavaValue result(T_LONG); 171 JavaCalls::call_static(&result, 172 klass, 173 vmSymbols::findNative_name(), 174 vmSymbols::classloader_string_long_signature(), 175 // Arguments 176 loader, 177 name_arg, 178 CHECK_NULL); 179 entry = (address) (intptr_t) result.get_jlong(); 180 181 if (entry == NULL) { 182 // findNative didn't find it, if there are any agent libraries look in them 183 AgentLibrary* agent; 184 for (agent = Arguments::agents(); agent != NULL; agent = agent->next()) { 185 entry = (address) os::dll_lookup(agent->os_lib(), jni_name); 186 if (entry != NULL) { 187 return entry; 188 } 189 } 190 } 191 192 return entry; 193 } 194 195 196 // Check all the formats of native implementation name to see if there is one 197 // for the specified method. 198 address NativeLookup::lookup_entry(methodHandle method, bool& in_base_library, TRAPS) { 199 address entry = NULL; 200 in_base_library = false; 201 // Compute pure name 202 char* pure_name = pure_jni_name(method); 203 204 // Compute argument size 205 int args_size = 1 // JNIEnv 206 + (method->is_static() ? 1 : 0) // class for static methods 207 + method->size_of_parameters(); // actual parameters 208 209 210 // 1) Try JNI short style 211 entry = lookup_style(method, pure_name, "", args_size, true, in_base_library, CHECK_NULL); 212 if (entry != NULL) return entry; 213 214 // Compute long name 215 char* long_name = long_jni_name(method); 216 217 // 2) Try JNI long style 218 entry = lookup_style(method, pure_name, long_name, args_size, true, in_base_library, CHECK_NULL); 219 if (entry != NULL) return entry; 220 221 // 3) Try JNI short style without os prefix/suffix 222 entry = lookup_style(method, pure_name, "", args_size, false, in_base_library, CHECK_NULL); 223 if (entry != NULL) return entry; 224 225 // 4) Try JNI long style without os prefix/suffix 226 entry = lookup_style(method, pure_name, long_name, args_size, false, in_base_library, CHECK_NULL); 227 228 return entry; // NULL indicates not found 229 } 230 231 // Check if there are any JVM TI prefixes which have been applied to the native method name. 232 // If any are found, remove them before attemping the look up of the 233 // native implementation again. 234 // See SetNativeMethodPrefix in the JVM TI Spec for more details. 235 address NativeLookup::lookup_entry_prefixed(methodHandle method, bool& in_base_library, TRAPS) { 236 ResourceMark rm(THREAD); 237 238 int prefix_count; 239 char** prefixes = JvmtiExport::get_all_native_method_prefixes(&prefix_count); 240 char* in_name = method->name()->as_C_string(); 241 char* wrapper_name = in_name; 242 // last applied prefix will be first -- go backwards 243 for (int i = prefix_count-1; i >= 0; i--) { 244 char* prefix = prefixes[i]; 245 size_t prefix_len = strlen(prefix); 246 if (strncmp(prefix, wrapper_name, prefix_len) == 0) { 247 // has this prefix remove it 248 wrapper_name += prefix_len; 249 } 250 } 251 if (wrapper_name != in_name) { 252 // we have a name for a wrapping method 253 int wrapper_name_len = (int)strlen(wrapper_name); 254 TempNewSymbol wrapper_symbol = SymbolTable::probe(wrapper_name, wrapper_name_len); 255 if (wrapper_symbol != NULL) { 256 KlassHandle kh(method->method_holder()); 257 methodOop wrapper_method = Klass::cast(kh())->lookup_method(wrapper_symbol, 258 method->signature()); 259 if (wrapper_method != NULL && !wrapper_method->is_native()) { 260 // we found a wrapper method, use its native entry 261 method->set_is_prefixed_native(); 262 return lookup_entry(wrapper_method, in_base_library, THREAD); 263 } 264 } 265 } 266 return NULL; 267 } 268 269 address NativeLookup::lookup_base(methodHandle method, bool& in_base_library, TRAPS) { 270 address entry = NULL; 271 ResourceMark rm(THREAD); 272 273 entry = lookup_entry(method, in_base_library, THREAD); 274 if (entry != NULL) return entry; 275 276 // standard native method resolution has failed. Check if there are any 277 // JVM TI prefixes which have been applied to the native method name. 278 entry = lookup_entry_prefixed(method, in_base_library, THREAD); 279 if (entry != NULL) return entry; 280 281 // Native function not found, throw UnsatisfiedLinkError 282 THROW_MSG_0(vmSymbols::java_lang_UnsatisfiedLinkError(), 283 method->name_and_sig_as_C_string()); 284 } 285 286 287 address NativeLookup::lookup(methodHandle method, bool& in_base_library, TRAPS) { 288 if (!method->has_native_function()) { 289 address entry = lookup_base(method, in_base_library, CHECK_NULL); 290 method->set_native_function(entry, 291 methodOopDesc::native_bind_event_is_interesting); 292 // -verbose:jni printing 293 if (PrintJNIResolving) { 294 ResourceMark rm(THREAD); 295 tty->print_cr("[Dynamic-linking native method %s.%s ... JNI]", 296 Klass::cast(method->method_holder())->external_name(), 297 method->name()->as_C_string()); 298 } 299 } 300 return method->native_function(); 301 } 302 303 address NativeLookup::base_library_lookup(const char* class_name, const char* method_name, const char* signature) { 304 EXCEPTION_MARK; 305 bool in_base_library = true; // SharedRuntime inits some math methods. 306 TempNewSymbol c_name = SymbolTable::new_symbol(class_name, CATCH); 307 TempNewSymbol m_name = SymbolTable::new_symbol(method_name, CATCH); 308 TempNewSymbol s_name = SymbolTable::new_symbol(signature, CATCH); 309 310 // Find the class 311 klassOop k = SystemDictionary::resolve_or_fail(c_name, true, CATCH); 312 instanceKlassHandle klass (THREAD, k); 313 314 // Find method and invoke standard lookup 315 methodHandle method (THREAD, 316 klass->uncached_lookup_method(m_name, s_name)); 317 address result = lookup(method, in_base_library, CATCH); 318 assert(in_base_library, "must be in basic library"); 319 guarantee(result != NULL, "must be non NULL"); 320 return result; 321 }