1 /*
2 * Copyright (c) 1997, 2012, 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 #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::critical_jni_name(methodHandle method) {
95 stringStream st;
96 // Prefix
97 st.print("JavaCritical_");
98 // Klass name
99 mangle_name_on(&st, method->klass_name());
100 st.print("_");
101 // Method name
102 mangle_name_on(&st, method->name());
103 return st.as_string();
104 }
105
106
107 char* NativeLookup::long_jni_name(methodHandle method) {
108 // Signature ignore the wrapping parenteses and the trailing return type
109 stringStream st;
110 Symbol* signature = method->signature();
111 st.print("__");
112 // find ')'
113 int end;
114 for (end = 0; end < signature->utf8_length() && signature->byte_at(end) != ')'; end++);
115 // skip first '('
116 mangle_name_on(&st, signature, 1, end);
117 return st.as_string();
118 }
119
120 extern "C" {
121 void JNICALL JVM_RegisterUnsafeMethods(JNIEnv *env, jclass unsafecls);
122 void JNICALL JVM_RegisterMethodHandleMethods(JNIEnv *env, jclass unsafecls);
123 void JNICALL JVM_RegisterPerfMethods(JNIEnv *env, jclass perfclass);
124 void JNICALL JVM_RegisterWhiteBoxMethods(JNIEnv *env, jclass wbclass);
125 }
126
127 #define CC (char*) /* cast a literal from (const char*) */
128 #define FN_PTR(f) CAST_FROM_FN_PTR(void*, &f)
129
130 static JNINativeMethod lookup_special_native_methods[] = {
131 // Next two functions only exist for compatibility with 1.3.1 and earlier.
132 { CC"Java_java_io_ObjectOutputStream_getPrimitiveFieldValues", NULL, FN_PTR(JVM_GetPrimitiveFieldValues) }, // intercept ObjectOutputStream getPrimitiveFieldValues for faster serialization
133 { CC"Java_java_io_ObjectInputStream_setPrimitiveFieldValues", NULL, FN_PTR(JVM_SetPrimitiveFieldValues) }, // intercept ObjectInputStream setPrimitiveFieldValues for faster serialization
134
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 i = !JDK_Version::is_gte_jdk14x_version() ? 0 : 2; // see comment in lookup_special_native_methods
143 int count = sizeof(lookup_special_native_methods) / sizeof(JNINativeMethod);
144 for (; i < count; i++) {
145 // NB: To ignore the jni prefix and jni postfix strstr is used matching.
146 if (strstr(jni_name, lookup_special_native_methods[i].name) != NULL) {
147 return CAST_FROM_FN_PTR(address, lookup_special_native_methods[i].fnPtr);
148 }
149 }
150 return NULL;
151 }
152
153 address NativeLookup::lookup_style(methodHandle method, char* pure_name, const char* long_name, int args_size, bool os_style, bool& in_base_library, TRAPS) {
154 address entry;
155 // Compute complete JNI name for style
156 stringStream st;
157 if (os_style) os::print_jni_name_prefix_on(&st, args_size);
158 st.print_raw(pure_name);
159 st.print_raw(long_name);
160 if (os_style) os::print_jni_name_suffix_on(&st, args_size);
161 char* jni_name = st.as_string();
162
163 // If the loader is null we have a system class, so we attempt a lookup in
164 // the native Java library. This takes care of any bootstrapping problems.
165 // Note: It is critical for bootstrapping that Java_java_lang_ClassLoader_00024NativeLibrary_find
166 // gets found the first time around - otherwise an infinite loop can occure. This is
167 // another VM/library dependency
168 Handle loader(THREAD,
169 InstanceKlass::cast(method->method_holder())->class_loader());
170 if (loader.is_null()) {
171 entry = lookup_special_native(jni_name);
172 if (entry == NULL) {
173 entry = (address) os::dll_lookup(os::native_java_library(), jni_name);
174 }
175 if (entry != NULL) {
176 in_base_library = true;
177 return entry;
178 }
179 }
180
181 // Otherwise call static method findNative in ClassLoader
182 KlassHandle klass (THREAD, SystemDictionary::ClassLoader_klass());
183 Handle name_arg = java_lang_String::create_from_str(jni_name, CHECK_NULL);
184
185 JavaValue result(T_LONG);
186 JavaCalls::call_static(&result,
187 klass,
188 vmSymbols::findNative_name(),
189 vmSymbols::classloader_string_long_signature(),
190 // Arguments
191 loader,
192 name_arg,
193 CHECK_NULL);
194 entry = (address) (intptr_t) result.get_jlong();
195
196 if (entry == NULL) {
197 // findNative didn't find it, if there are any agent libraries look in them
198 AgentLibrary* agent;
199 for (agent = Arguments::agents(); agent != NULL; agent = agent->next()) {
200 entry = (address) os::dll_lookup(agent->os_lib(), jni_name);
201 if (entry != NULL) {
202 return entry;
203 }
204 }
205 }
206
207 return entry;
208 }
209
210
211 address NativeLookup::lookup_critical_style(methodHandle method, char* pure_name, const char* long_name, int args_size, bool os_style) {
212 if (!method->has_native_function()) {
213 return NULL;
214 }
215
216 address current_entry = method->native_function();
217
218 char dll_name[JVM_MAXPATHLEN];
219 int offset;
220 if (os::dll_address_to_library_name(current_entry, dll_name, sizeof(dll_name), &offset)) {
221 char ebuf[32];
222 void* dll = os::dll_load(dll_name, ebuf, sizeof(ebuf));
223 if (dll != NULL) {
224 // Compute complete JNI name for style
225 stringStream st;
226 if (os_style) os::print_jni_name_prefix_on(&st, args_size);
227 st.print_raw(pure_name);
228 st.print_raw(long_name);
229 if (os_style) os::print_jni_name_suffix_on(&st, args_size);
230 char* jni_name = st.as_string();
231 return (address)os::dll_lookup(dll, jni_name);
232 }
233 }
234
235 return NULL;
236 }
237
238
239 // Check all the formats of native implementation name to see if there is one
240 // for the specified method.
241 address NativeLookup::lookup_entry(methodHandle method, bool& in_base_library, TRAPS) {
242 address entry = NULL;
243 in_base_library = false;
244 // Compute pure name
245 char* pure_name = pure_jni_name(method);
246
247 // Compute argument size
248 int args_size = 1 // JNIEnv
249 + (method->is_static() ? 1 : 0) // class for static methods
250 + method->size_of_parameters(); // actual parameters
251
252
253 // 1) Try JNI short style
254 entry = lookup_style(method, pure_name, "", args_size, true, in_base_library, CHECK_NULL);
255 if (entry != NULL) return entry;
256
257 // Compute long name
258 char* long_name = long_jni_name(method);
259
260 // 2) Try JNI long style
261 entry = lookup_style(method, pure_name, long_name, args_size, true, in_base_library, CHECK_NULL);
262 if (entry != NULL) return entry;
263
264 // 3) Try JNI short style without os prefix/suffix
265 entry = lookup_style(method, pure_name, "", args_size, false, in_base_library, CHECK_NULL);
266 if (entry != NULL) return entry;
267
268 // 4) Try JNI long style without os prefix/suffix
269 entry = lookup_style(method, pure_name, long_name, args_size, false, in_base_library, CHECK_NULL);
270
271 return entry; // NULL indicates not found
272 }
273
274 // Check all the formats of native implementation name to see if there is one
275 // for the specified method.
276 address NativeLookup::lookup_critical_entry(methodHandle method) {
277 if (!CriticalJNINatives) return NULL;
278
279 if (method->is_synchronized() ||
280 !method->is_static()) {
281 // Only static non-synchronized methods are allowed
282 return NULL;
283 }
284
285 ResourceMark rm;
286 address entry = NULL;
287
288 Symbol* signature = method->signature();
289 for (int end = 0; end < signature->utf8_length(); end++) {
290 if (signature->byte_at(end) == 'L') {
291 // Don't allow object types
292 return NULL;
293 }
294 }
295
296 // Compute critical name
297 char* critical_name = critical_jni_name(method);
298
299 // Compute argument size
300 int args_size = 1 // JNIEnv
301 + (method->is_static() ? 1 : 0) // class for static methods
302 + method->size_of_parameters(); // actual parameters
303
304
305 // 1) Try JNI short style
306 entry = lookup_critical_style(method, critical_name, "", args_size, true);
307 if (entry != NULL) return entry;
308
309 // Compute long name
310 char* long_name = long_jni_name(method);
311
312 // 2) Try JNI long style
313 entry = lookup_critical_style(method, critical_name, long_name, args_size, true);
314 if (entry != NULL) return entry;
315
316 // 3) Try JNI short style without os prefix/suffix
317 entry = lookup_critical_style(method, critical_name, "", args_size, false);
318 if (entry != NULL) return entry;
319
320 // 4) Try JNI long style without os prefix/suffix
321 entry = lookup_critical_style(method, critical_name, long_name, args_size, false);
322
323 return entry; // NULL indicates not found
324 }
325
326 // Check if there are any JVM TI prefixes which have been applied to the native method name.
327 // If any are found, remove them before attemping the look up of the
328 // native implementation again.
329 // See SetNativeMethodPrefix in the JVM TI Spec for more details.
330 address NativeLookup::lookup_entry_prefixed(methodHandle method, bool& in_base_library, TRAPS) {
331 ResourceMark rm(THREAD);
332
333 int prefix_count;
334 char** prefixes = JvmtiExport::get_all_native_method_prefixes(&prefix_count);
335 char* in_name = method->name()->as_C_string();
336 char* wrapper_name = in_name;
337 // last applied prefix will be first -- go backwards
338 for (int i = prefix_count-1; i >= 0; i--) {
339 char* prefix = prefixes[i];
340 size_t prefix_len = strlen(prefix);
341 if (strncmp(prefix, wrapper_name, prefix_len) == 0) {
342 // has this prefix remove it
343 wrapper_name += prefix_len;
344 }
345 }
346 if (wrapper_name != in_name) {
347 // we have a name for a wrapping method
348 int wrapper_name_len = (int)strlen(wrapper_name);
349 TempNewSymbol wrapper_symbol = SymbolTable::probe(wrapper_name, wrapper_name_len);
350 if (wrapper_symbol != NULL) {
351 KlassHandle kh(method->method_holder());
352 Method* wrapper_method = Klass::cast(kh())->lookup_method(wrapper_symbol,
353 method->signature());
354 if (wrapper_method != NULL && !wrapper_method->is_native()) {
355 // we found a wrapper method, use its native entry
356 method->set_is_prefixed_native();
357 return lookup_entry(wrapper_method, in_base_library, THREAD);
358 }
359 }
360 }
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 =
385 method->intrinsic_id() == vmIntrinsics::_invokeGeneric ?
386 SharedRuntime::native_method_throw_unsupported_operation_exception_entry() :
387 lookup_base(method, in_base_library, CHECK_NULL);
388 method->set_native_function(entry,
389 Method::native_bind_event_is_interesting);
390 // -verbose:jni printing
391 if (PrintJNIResolving) {
392 ResourceMark rm(THREAD);
393 tty->print_cr("[Dynamic-linking native method %s.%s ... JNI]",
394 Klass::cast(method->method_holder())->external_name(),
395 method->name()->as_C_string());
396 }
397 }
398 return method->native_function();
399 }
400
401 address NativeLookup::base_library_lookup(const char* class_name, const char* method_name, const char* signature) {
402 EXCEPTION_MARK;
403 bool in_base_library = true; // SharedRuntime inits some math methods.
404 TempNewSymbol c_name = SymbolTable::new_symbol(class_name, CATCH);
405 TempNewSymbol m_name = SymbolTable::new_symbol(method_name, CATCH);
406 TempNewSymbol s_name = SymbolTable::new_symbol(signature, CATCH);
407
408 // Find the class
409 Klass* k = SystemDictionary::resolve_or_fail(c_name, true, CATCH);
410 instanceKlassHandle klass (THREAD, k);
411
412 // Find method and invoke standard lookup
413 methodHandle method (THREAD,
414 klass->uncached_lookup_method(m_name, s_name));
415 address result = lookup(method, in_base_library, CATCH);
416 assert(in_base_library, "must be in basic library");
417 guarantee(result != NULL, "must be non NULL");
418 return result;
419 }