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 #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 // Next two functions only exist for compatibility with 1.3.1 and earlier.
136 { CC"Java_java_io_ObjectOutputStream_getPrimitiveFieldValues", NULL, FN_PTR(JVM_GetPrimitiveFieldValues) }, // intercept ObjectOutputStream getPrimitiveFieldValues for faster serialization
137 { CC"Java_java_io_ObjectInputStream_setPrimitiveFieldValues", NULL, FN_PTR(JVM_SetPrimitiveFieldValues) }, // intercept ObjectInputStream setPrimitiveFieldValues for faster serialization
138
139 { CC"Java_sun_misc_Unsafe_registerNatives", NULL, FN_PTR(JVM_RegisterUnsafeMethods) },
140 { CC"Java_java_lang_invoke_MethodHandleNatives_registerNatives", NULL, FN_PTR(JVM_RegisterMethodHandleMethods) },
141 { CC"Java_sun_misc_Perf_registerNatives", NULL, FN_PTR(JVM_RegisterPerfMethods) },
142 { CC"Java_sun_hotspot_WhiteBox_registerNatives", NULL, FN_PTR(JVM_RegisterWhiteBoxMethods) },
143 };
144
145 static address lookup_special_native(char* jni_name) {
146 int i = !JDK_Version::is_gte_jdk14x_version() ? 0 : 2; // see comment in lookup_special_native_methods
147 int count = sizeof(lookup_special_native_methods) / sizeof(JNINativeMethod);
148 for (; i < count; i++) {
149 // NB: To ignore the jni prefix and jni postfix strstr is used matching.
150 if (strstr(jni_name, lookup_special_native_methods[i].name) != NULL) {
151 return CAST_FROM_FN_PTR(address, lookup_special_native_methods[i].fnPtr);
152 }
153 }
154 return NULL;
155 }
156
157 address NativeLookup::lookup_style(methodHandle method, char* pure_name, const char* long_name, int args_size, bool os_style, bool& in_base_library, TRAPS) {
158 address entry;
159 // Compute complete JNI name for style
160 stringStream st;
161 if (os_style) os::print_jni_name_prefix_on(&st, args_size);
162 st.print_raw(pure_name);
163 st.print_raw(long_name);
164 if (os_style) os::print_jni_name_suffix_on(&st, args_size);
165 char* jni_name = st.as_string();
166
167 // If the loader is null we have a system class, so we attempt a lookup in
168 // the native Java library. This takes care of any bootstrapping problems.
169 // Note: It is critical for bootstrapping that Java_java_lang_ClassLoader_00024NativeLibrary_find
170 // gets found the first time around - otherwise an infinite loop can occure. This is
171 // another VM/library dependency
172 Handle loader(THREAD, method->method_holder()->class_loader());
173 if (loader.is_null()) {
174 entry = lookup_special_native(jni_name);
175 if (entry == NULL) {
176 entry = (address) os::dll_lookup(os::native_java_library(), jni_name);
177 }
178 if (entry != NULL) {
179 in_base_library = true;
180 return entry;
181 }
182 }
183
184 // Otherwise call static method findNative in ClassLoader
185 KlassHandle klass (THREAD, SystemDictionary::ClassLoader_klass());
186 Handle name_arg = java_lang_String::create_from_str(jni_name, CHECK_NULL);
187
188 JavaValue result(T_LONG);
189 JavaCalls::call_static(&result,
190 klass,
191 vmSymbols::findNative_name(),
192 vmSymbols::classloader_string_long_signature(),
193 // Arguments
194 loader,
195 name_arg,
196 CHECK_NULL);
197 entry = (address) (intptr_t) result.get_jlong();
198
199 if (entry == NULL) {
200 // findNative didn't find it, if there are any agent libraries look in them
201 AgentLibrary* agent;
202 for (agent = Arguments::agents(); agent != NULL; agent = agent->next()) {
203 entry = (address) os::dll_lookup(agent->os_lib(), jni_name);
204 if (entry != NULL) {
205 return entry;
206 }
207 }
208 }
209
210 return entry;
211 }
212
213
214 address NativeLookup::lookup_critical_style(methodHandle method, char* pure_name, const char* long_name, int args_size, bool os_style) {
215 if (!method->has_native_function()) {
216 return NULL;
217 }
218
219 address current_entry = method->native_function();
220
221 char dll_name[JVM_MAXPATHLEN];
222 int offset;
223 if (os::dll_address_to_library_name(current_entry, dll_name, sizeof(dll_name), &offset)) {
224 char ebuf[32];
225 void* dll = os::dll_load(dll_name, ebuf, sizeof(ebuf));
226 if (dll != NULL) {
227 // Compute complete JNI name for style
228 stringStream st;
229 if (os_style) os::print_jni_name_prefix_on(&st, args_size);
230 st.print_raw(pure_name);
231 st.print_raw(long_name);
232 if (os_style) os::print_jni_name_suffix_on(&st, args_size);
233 char* jni_name = st.as_string();
234 return (address)os::dll_lookup(dll, jni_name);
235 }
236 }
237
238 return NULL;
239 }
240
241
242 // Check all the formats of native implementation name to see if there is one
243 // for the specified method.
244 address NativeLookup::lookup_entry(methodHandle method, bool& in_base_library, TRAPS) {
245 address entry = NULL;
246 in_base_library = false;
247 // Compute pure name
248 char* pure_name = pure_jni_name(method);
249
250 // Compute argument size
251 int args_size = 1 // JNIEnv
252 + (method->is_static() ? 1 : 0) // class for static methods
253 + method->size_of_parameters(); // actual parameters
254
255
256 // 1) Try JNI short style
257 entry = lookup_style(method, pure_name, "", args_size, true, in_base_library, CHECK_NULL);
258 if (entry != NULL) return entry;
259
260 // Compute long name
261 char* long_name = long_jni_name(method);
262
263 // 2) Try JNI long style
264 entry = lookup_style(method, pure_name, long_name, args_size, true, in_base_library, CHECK_NULL);
265 if (entry != NULL) return entry;
266
267 // 3) Try JNI short style without os prefix/suffix
268 entry = lookup_style(method, pure_name, "", args_size, false, in_base_library, CHECK_NULL);
269 if (entry != NULL) return entry;
270
271 // 4) Try JNI long style without os prefix/suffix
272 entry = lookup_style(method, pure_name, long_name, args_size, false, in_base_library, CHECK_NULL);
273
274 return entry; // NULL indicates not found
275 }
276
277 // Check all the formats of native implementation name to see if there is one
278 // for the specified method.
279 address NativeLookup::lookup_critical_entry(methodHandle method) {
280 if (!CriticalJNINatives) return NULL;
281
282 if (method->is_synchronized() ||
283 !method->is_static()) {
284 // Only static non-synchronized methods are allowed
285 return NULL;
286 }
287
288 ResourceMark rm;
289 address entry = NULL;
290
291 Symbol* signature = method->signature();
292 for (int end = 0; end < signature->utf8_length(); end++) {
293 if (signature->byte_at(end) == 'L') {
294 // Don't allow object types
295 return NULL;
296 }
297 }
298
299 // Compute critical name
300 char* critical_name = critical_jni_name(method);
301
302 // Compute argument size
303 int args_size = 1 // JNIEnv
304 + (method->is_static() ? 1 : 0) // class for static methods
305 + method->size_of_parameters(); // actual parameters
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(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 KlassHandle kh(method->method_holder());
356 Method* wrapper_method = kh()->lookup_method(wrapper_symbol,
357 method->signature());
358 if (wrapper_method != NULL && !wrapper_method->is_native()) {
359 // we found a wrapper method, use its native entry
360 method->set_is_prefixed_native();
361 return lookup_entry(wrapper_method, in_base_library, THREAD);
362 }
363 }
364 }
365 #endif // INCLUDE_JVMTI
366 return NULL;
367 }
368
369 address NativeLookup::lookup_base(methodHandle method, bool& in_base_library, TRAPS) {
370 address entry = NULL;
371 ResourceMark rm(THREAD);
372
373 entry = lookup_entry(method, in_base_library, THREAD);
374 if (entry != NULL) return entry;
375
376 // standard native method resolution has failed. Check if there are any
377 // JVM TI prefixes which have been applied to the native method name.
378 entry = lookup_entry_prefixed(method, in_base_library, THREAD);
379 if (entry != NULL) return entry;
380
381 // Native function not found, throw UnsatisfiedLinkError
382 THROW_MSG_0(vmSymbols::java_lang_UnsatisfiedLinkError(),
383 method->name_and_sig_as_C_string());
384 }
385
386
387 address NativeLookup::lookup(methodHandle method, bool& in_base_library, TRAPS) {
388 if (!method->has_native_function()) {
389 address entry = lookup_base(method, in_base_library, CHECK_NULL);
390 method->set_native_function(entry,
391 Method::native_bind_event_is_interesting);
392 // -verbose:jni printing
393 if (PrintJNIResolving) {
394 ResourceMark rm(THREAD);
395 tty->print_cr("[Dynamic-linking native method %s.%s ... JNI]",
396 method->method_holder()->external_name(),
397 method->name()->as_C_string());
398 }
399 }
400 return method->native_function();
401 }
402
403 address NativeLookup::base_library_lookup(const char* class_name, const char* method_name, const char* signature) {
404 EXCEPTION_MARK;
405 bool in_base_library = true; // SharedRuntime inits some math methods.
406 TempNewSymbol c_name = SymbolTable::new_symbol(class_name, CATCH);
407 TempNewSymbol m_name = SymbolTable::new_symbol(method_name, CATCH);
408 TempNewSymbol s_name = SymbolTable::new_symbol(signature, CATCH);
409
410 // Find the class
411 Klass* k = SystemDictionary::resolve_or_fail(c_name, true, CATCH);
412 instanceKlassHandle klass (THREAD, k);
413
414 // Find method and invoke standard lookup
415 methodHandle method (THREAD,
416 klass->uncached_lookup_method(m_name, s_name));
417 address result = lookup(method, in_base_library, CATCH);
418 assert(in_base_library, "must be in basic library");
419 guarantee(result != NULL, "must be non NULL");
420 return result;
421 }