1 /*
2 * Copyright (c) 1997, 2015, 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
45
46 static void mangle_name_on(outputStream* st, Symbol* name, int begin, int end) {
47 char* bytes = (char*)name->bytes() + begin;
48 char* end_bytes = (char*)name->bytes() + end;
49 while (bytes < end_bytes) {
50 jchar c;
51 bytes = UTF8::next(bytes, &c);
52 if (c <= 0x7f && isalnum(c)) {
53 st->put((char) c);
54 } else {
55 if (c == '_') st->print("_1");
56 else if (c == '/') st->print("_");
57 else if (c == ';') st->print("_2");
58 else if (c == '[') st->print("_3");
59 else st->print("_%.5x", c);
60 }
61 }
62 }
63
64
65 static void mangle_name_on(outputStream* st, Symbol* name) {
66 mangle_name_on(st, name, 0, name->utf8_length());
67 }
68
69
70 char* NativeLookup::pure_jni_name(methodHandle method) {
71 stringStream st;
72 // Prefix
73 st.print("Java_");
74 // Klass name
75 mangle_name_on(&st, method->klass_name());
76 st.print("_");
77 // Method name
78 mangle_name_on(&st, method->name());
79 return st.as_string();
80 }
81
82
83 char* NativeLookup::critical_jni_name(methodHandle method) {
84 stringStream st;
85 // Prefix
86 st.print("JavaCritical_");
87 // Klass name
88 mangle_name_on(&st, method->klass_name());
89 st.print("_");
90 // Method name
91 mangle_name_on(&st, method->name());
92 return st.as_string();
93 }
94
95
96 char* NativeLookup::long_jni_name(methodHandle method) {
97 // Signature ignore the wrapping parenteses and the trailing return type
98 stringStream st;
99 Symbol* signature = method->signature();
100 st.print("__");
101 // find ')'
102 int end;
103 for (end = 0; end < signature->utf8_length() && signature->byte_at(end) != ')'; end++);
104 // skip first '('
105 mangle_name_on(&st, signature, 1, end);
106 return st.as_string();
107 }
108
109 extern "C" {
110 void JNICALL JVM_RegisterUnsafeMethods(JNIEnv *env, jclass unsafecls);
111 void JNICALL JVM_RegisterMethodHandleMethods(JNIEnv *env, jclass unsafecls);
112 void JNICALL JVM_RegisterPerfMethods(JNIEnv *env, jclass perfclass);
113 void JNICALL JVM_RegisterWhiteBoxMethods(JNIEnv *env, jclass wbclass);
114 #if INCLUDE_JVMCI
115 jobject JNICALL JVM_GetJVMCIRuntime(JNIEnv *env, jclass c);
116 void JNICALL JVM_RegisterJVMCINatives(JNIEnv *env, jclass compilerToVMClass);
117 #endif
118 }
119
120 #define CC (char*) /* cast a literal from (const char*) */
121 #define FN_PTR(f) CAST_FROM_FN_PTR(void*, &f)
122
123 static JNINativeMethod lookup_special_native_methods[] = {
124 { CC"Java_jdk_internal_misc_Unsafe_registerNatives", NULL, FN_PTR(JVM_RegisterUnsafeMethods) },
125 { CC"Java_sun_misc_Unsafe_registerNatives", NULL, FN_PTR(JVM_RegisterUnsafeMethods) },
126 { CC"Java_java_lang_invoke_MethodHandleNatives_registerNatives", NULL, FN_PTR(JVM_RegisterMethodHandleMethods) },
127 { CC"Java_sun_misc_Perf_registerNatives", NULL, FN_PTR(JVM_RegisterPerfMethods) },
128 { CC"Java_sun_hotspot_WhiteBox_registerNatives", NULL, FN_PTR(JVM_RegisterWhiteBoxMethods) },
129 #if INCLUDE_JVMCI
130 { CC"Java_jdk_vm_ci_runtime_JVMCI_initializeRuntime", NULL, FN_PTR(JVM_GetJVMCIRuntime) },
131 { CC"Java_jdk_vm_ci_hotspot_CompilerToVM_registerNatives", NULL, FN_PTR(JVM_RegisterJVMCINatives) },
132 #endif
133 };
134
135 static address lookup_special_native(char* jni_name) {
136 int count = sizeof(lookup_special_native_methods) / sizeof(JNINativeMethod);
137 for (int i = 0; i < count; i++) {
138 // NB: To ignore the jni prefix and jni postfix strstr is used matching.
139 if (strstr(jni_name, lookup_special_native_methods[i].name) != NULL) {
140 return CAST_FROM_FN_PTR(address, lookup_special_native_methods[i].fnPtr);
141 }
142 }
143 return NULL;
144 }
145
146 address NativeLookup::lookup_style(methodHandle method, char* pure_name, const char* long_name, int args_size, bool os_style, bool& in_base_library, TRAPS) {
147 address entry;
148 // Compute complete JNI name for style
149 stringStream st;
150 if (os_style) os::print_jni_name_prefix_on(&st, args_size);
151 st.print_raw(pure_name);
152 st.print_raw(long_name);
153 if (os_style) os::print_jni_name_suffix_on(&st, args_size);
154 char* jni_name = st.as_string();
155
156 // If the loader is null we have a system class, so we attempt a lookup in
157 // the native Java library. This takes care of any bootstrapping problems.
158 // Note: It is critical for bootstrapping that Java_java_lang_ClassLoader_00024NativeLibrary_find
159 // gets found the first time around - otherwise an infinite loop can occure. This is
160 // another VM/library dependency
161 Handle loader(THREAD, method->method_holder()->class_loader());
162 if (loader.is_null()) {
163 entry = lookup_special_native(jni_name);
164 if (entry == NULL) {
165 entry = (address) os::dll_lookup(os::native_java_library(), jni_name);
166 }
167 if (entry != NULL) {
168 in_base_library = true;
169 return entry;
170 }
171 }
172
173 // Otherwise call static method findNative in ClassLoader
174 KlassHandle klass (THREAD, SystemDictionary::ClassLoader_klass());
175 Handle name_arg = java_lang_String::create_from_str(jni_name, CHECK_NULL);
176
177 JavaValue result(T_LONG);
178 JavaCalls::call_static(&result,
179 klass,
180 vmSymbols::findNative_name(),
181 vmSymbols::classloader_string_long_signature(),
182 // Arguments
183 loader,
184 name_arg,
185 CHECK_NULL);
186 entry = (address) (intptr_t) result.get_jlong();
187
188 if (entry == NULL) {
189 // findNative didn't find it, if there are any agent libraries look in them
190 AgentLibrary* agent;
191 for (agent = Arguments::agents(); agent != NULL; agent = agent->next()) {
192 entry = (address) os::dll_lookup(agent->os_lib(), jni_name);
193 if (entry != NULL) {
194 return entry;
195 }
196 }
197 }
198
199 return entry;
200 }
201
202
203 address NativeLookup::lookup_critical_style(methodHandle method, char* pure_name, const char* long_name, int args_size, bool os_style) {
204 if (!method->has_native_function()) {
205 return NULL;
206 }
207
208 address current_entry = method->native_function();
209
210 char dll_name[JVM_MAXPATHLEN];
211 int offset;
212 if (os::dll_address_to_library_name(current_entry, dll_name, sizeof(dll_name), &offset)) {
213 char ebuf[32];
214 void* dll = os::dll_load(dll_name, ebuf, sizeof(ebuf));
215 if (dll != NULL) {
216 // Compute complete JNI name for style
217 stringStream st;
218 if (os_style) os::print_jni_name_prefix_on(&st, args_size);
219 st.print_raw(pure_name);
220 st.print_raw(long_name);
221 if (os_style) os::print_jni_name_suffix_on(&st, args_size);
222 char* jni_name = st.as_string();
223 return (address)os::dll_lookup(dll, jni_name);
224 }
225 }
226
227 return NULL;
228 }
229
230
231 // Check all the formats of native implementation name to see if there is one
232 // for the specified method.
233 address NativeLookup::lookup_entry(methodHandle method, bool& in_base_library, TRAPS) {
234 address entry = NULL;
235 in_base_library = false;
236 // Compute pure name
237 char* pure_name = pure_jni_name(method);
238
239 // Compute argument size
240 int args_size = 1 // JNIEnv
241 + (method->is_static() ? 1 : 0) // class for static methods
242 + method->size_of_parameters(); // actual parameters
243
244
245 // 1) Try JNI short style
246 entry = lookup_style(method, pure_name, "", args_size, true, in_base_library, CHECK_NULL);
247 if (entry != NULL) return entry;
248
249 // Compute long name
250 char* long_name = long_jni_name(method);
251
252 // 2) Try JNI long style
253 entry = lookup_style(method, pure_name, long_name, args_size, true, in_base_library, CHECK_NULL);
254 if (entry != NULL) return entry;
255
256 // 3) Try JNI short style without os prefix/suffix
257 entry = lookup_style(method, pure_name, "", args_size, false, in_base_library, CHECK_NULL);
258 if (entry != NULL) return entry;
259
260 // 4) Try JNI long style without os prefix/suffix
261 entry = lookup_style(method, pure_name, long_name, args_size, false, in_base_library, CHECK_NULL);
262
263 return entry; // NULL indicates not found
264 }
265
266 // Check all the formats of native implementation name to see if there is one
267 // for the specified method.
268 address NativeLookup::lookup_critical_entry(methodHandle method) {
269 if (!CriticalJNINatives) return NULL;
270
271 if (method->is_synchronized() ||
272 !method->is_static()) {
273 // Only static non-synchronized methods are allowed
274 return NULL;
275 }
276
277 ResourceMark rm;
278 address entry = NULL;
279
280 Symbol* signature = method->signature();
281 for (int end = 0; end < signature->utf8_length(); end++) {
282 if (signature->byte_at(end) == 'L') {
283 // Don't allow object types
284 return NULL;
285 }
286 }
287
288 // Compute critical name
289 char* critical_name = critical_jni_name(method);
290
291 // Compute argument size
292 int args_size = 1 // JNIEnv
293 + (method->is_static() ? 1 : 0) // class for static methods
294 + method->size_of_parameters(); // actual parameters
295
296
297 // 1) Try JNI short style
298 entry = lookup_critical_style(method, critical_name, "", args_size, true);
299 if (entry != NULL) return entry;
300
301 // Compute long name
302 char* long_name = long_jni_name(method);
303
304 // 2) Try JNI long style
305 entry = lookup_critical_style(method, critical_name, long_name, args_size, true);
306 if (entry != NULL) return entry;
307
308 // 3) Try JNI short style without os prefix/suffix
309 entry = lookup_critical_style(method, critical_name, "", args_size, false);
310 if (entry != NULL) return entry;
311
312 // 4) Try JNI long style without os prefix/suffix
313 entry = lookup_critical_style(method, critical_name, long_name, args_size, false);
314
315 return entry; // NULL indicates not found
316 }
317
318 // Check if there are any JVM TI prefixes which have been applied to the native method name.
319 // If any are found, remove them before attemping the look up of the
320 // native implementation again.
321 // See SetNativeMethodPrefix in the JVM TI Spec for more details.
322 address NativeLookup::lookup_entry_prefixed(methodHandle method, bool& in_base_library, TRAPS) {
323 #if INCLUDE_JVMTI
324 ResourceMark rm(THREAD);
325
326 int prefix_count;
327 char** prefixes = JvmtiExport::get_all_native_method_prefixes(&prefix_count);
328 char* in_name = method->name()->as_C_string();
329 char* wrapper_name = in_name;
330 // last applied prefix will be first -- go backwards
331 for (int i = prefix_count-1; i >= 0; i--) {
332 char* prefix = prefixes[i];
333 size_t prefix_len = strlen(prefix);
334 if (strncmp(prefix, wrapper_name, prefix_len) == 0) {
335 // has this prefix remove it
336 wrapper_name += prefix_len;
337 }
338 }
339 if (wrapper_name != in_name) {
340 // we have a name for a wrapping method
341 int wrapper_name_len = (int)strlen(wrapper_name);
342 TempNewSymbol wrapper_symbol = SymbolTable::probe(wrapper_name, wrapper_name_len);
343 if (wrapper_symbol != NULL) {
344 KlassHandle kh(method->method_holder());
345 Method* wrapper_method = kh()->lookup_method(wrapper_symbol,
346 method->signature());
347 if (wrapper_method != NULL && !wrapper_method->is_native()) {
348 // we found a wrapper method, use its native entry
349 method->set_is_prefixed_native();
350 return lookup_entry(wrapper_method, in_base_library, THREAD);
351 }
352 }
353 }
354 #endif // INCLUDE_JVMTI
355 return NULL;
356 }
357
358 address NativeLookup::lookup_base(methodHandle method, bool& in_base_library, TRAPS) {
359 address entry = NULL;
360 ResourceMark rm(THREAD);
361
362 entry = lookup_entry(method, in_base_library, THREAD);
363 if (entry != NULL) return entry;
364
365 // standard native method resolution has failed. Check if there are any
366 // JVM TI prefixes which have been applied to the native method name.
367 entry = lookup_entry_prefixed(method, in_base_library, THREAD);
368 if (entry != NULL) return entry;
369
370 // Native function not found, throw UnsatisfiedLinkError
371 THROW_MSG_0(vmSymbols::java_lang_UnsatisfiedLinkError(),
372 method->name_and_sig_as_C_string());
373 }
374
375
376 address NativeLookup::lookup(methodHandle method, bool& in_base_library, TRAPS) {
377 if (!method->has_native_function()) {
378 address entry = lookup_base(method, in_base_library, CHECK_NULL);
379 method->set_native_function(entry,
380 Method::native_bind_event_is_interesting);
381 // -verbose:jni printing
382 if (PrintJNIResolving) {
383 ResourceMark rm(THREAD);
384 tty->print_cr("[Dynamic-linking native method %s.%s ... JNI]",
385 method->method_holder()->external_name(),
386 method->name()->as_C_string());
387 }
388 }
389 return method->native_function();
390 }
391
392 address NativeLookup::base_library_lookup(const char* class_name, const char* method_name, const char* signature) {
393 EXCEPTION_MARK;
394 bool in_base_library = true; // SharedRuntime inits some math methods.
395 TempNewSymbol c_name = SymbolTable::new_symbol(class_name, CATCH);
396 TempNewSymbol m_name = SymbolTable::new_symbol(method_name, CATCH);
397 TempNewSymbol s_name = SymbolTable::new_symbol(signature, CATCH);
398
399 // Find the class
400 Klass* k = SystemDictionary::resolve_or_fail(c_name, true, CATCH);
401 instanceKlassHandle klass (THREAD, k);
402
403 // Find method and invoke standard lookup
404 methodHandle method (THREAD,
405 klass->uncached_lookup_method(m_name, s_name, Klass::find_overpass));
406 address result = lookup(method, in_base_library, CATCH);
407 assert(in_base_library, "must be in basic library");
408 guarantee(result != NULL, "must be non NULL");
409 return result;
410 }