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 #if INCLUDE_JFR
45 #include "jfr/jfr.hpp"
46 #endif
47 #ifdef TARGET_OS_FAMILY_linux
48 # include "os_linux.inline.hpp"
49 #endif
50 #ifdef TARGET_OS_FAMILY_solaris
51 # include "os_solaris.inline.hpp"
52 #endif
53 #ifdef TARGET_OS_FAMILY_windows
54 # include "os_windows.inline.hpp"
55 #endif
56 #ifdef TARGET_OS_FAMILY_aix
57 # include "os_aix.inline.hpp"
58 #endif
59 #ifdef TARGET_OS_FAMILY_bsd
60 # include "os_bsd.inline.hpp"
61 #endif
62
63
64 static void mangle_name_on(outputStream* st, Symbol* name, int begin, int end) {
65 char* bytes = (char*)name->bytes() + begin;
66 char* end_bytes = (char*)name->bytes() + end;
67 while (bytes < end_bytes) {
68 jchar c;
69 bytes = UTF8::next(bytes, &c);
70 if (c <= 0x7f && isalnum(c)) {
71 st->put((char) c);
72 } else {
73 if (c == '_') st->print("_1");
74 else if (c == '/') st->print("_");
75 else if (c == ';') st->print("_2");
76 else if (c == '[') st->print("_3");
77 else st->print("_%.5x", c);
78 }
79 }
80 }
81
82
83 static void mangle_name_on(outputStream* st, Symbol* name) {
84 mangle_name_on(st, name, 0, name->utf8_length());
85 }
86
87
88 char* NativeLookup::pure_jni_name(methodHandle method) {
89 stringStream st;
90 // Prefix
91 st.print("Java_");
92 // Klass name
93 mangle_name_on(&st, method->klass_name());
94 st.print("_");
95 // Method name
96 mangle_name_on(&st, method->name());
97 return st.as_string();
98 }
99
100
101 char* NativeLookup::critical_jni_name(methodHandle method) {
102 stringStream st;
103 // Prefix
104 st.print("JavaCritical_");
105 // Klass name
106 mangle_name_on(&st, method->klass_name());
107 st.print("_");
108 // Method name
109 mangle_name_on(&st, method->name());
110 return st.as_string();
111 }
112
113
114 char* NativeLookup::long_jni_name(methodHandle method) {
115 // Signature ignore the wrapping parenteses and the trailing return type
116 stringStream st;
117 Symbol* signature = method->signature();
118 st.print("__");
119 // find ')'
120 int end;
121 for (end = 0; end < signature->utf8_length() && signature->byte_at(end) != ')'; end++);
122 // skip first '('
123 mangle_name_on(&st, signature, 1, end);
124 return st.as_string();
125 }
126
127 extern "C" {
128 void JNICALL JVM_RegisterUnsafeMethods(JNIEnv *env, jclass unsafecls);
129 void JNICALL JVM_RegisterMethodHandleMethods(JNIEnv *env, jclass unsafecls);
130 void JNICALL JVM_RegisterPerfMethods(JNIEnv *env, jclass perfclass);
131 void JNICALL JVM_RegisterWhiteBoxMethods(JNIEnv *env, jclass wbclass);
132 }
133
134 #define CC (char*) /* cast a literal from (const char*) */
135 #define FN_PTR(f) CAST_FROM_FN_PTR(void*, &f)
136
137 static JNINativeMethod lookup_special_native_methods[] = {
138 { CC"Java_sun_misc_Unsafe_registerNatives", NULL, FN_PTR(JVM_RegisterUnsafeMethods) },
139 { CC"Java_java_lang_invoke_MethodHandleNatives_registerNatives", NULL, FN_PTR(JVM_RegisterMethodHandleMethods) },
140 { CC"Java_sun_misc_Perf_registerNatives", NULL, FN_PTR(JVM_RegisterPerfMethods) },
141 { CC"Java_sun_hotspot_WhiteBox_registerNatives", NULL, FN_PTR(JVM_RegisterWhiteBoxMethods) },
142 #if INCLUDE_JFR
143 { CC"Java_jdk_jfr_internal_JVM_registerNatives", NULL, FN_PTR(jfr_register_natives) },
144 #endif
145 };
146
147 static address lookup_special_native(char* jni_name) {
148 int count = sizeof(lookup_special_native_methods) / sizeof(JNINativeMethod);
149 for (int i = 0; i < count; i++) {
150 // NB: To ignore the jni prefix and jni postfix strstr is used matching.
151 if (strstr(jni_name, lookup_special_native_methods[i].name) != NULL) {
152 return CAST_FROM_FN_PTR(address, lookup_special_native_methods[i].fnPtr);
153 }
154 }
155 return NULL;
156 }
157
158 address NativeLookup::lookup_style(methodHandle method, char* pure_name, const char* long_name, int args_size, bool os_style, bool& in_base_library, TRAPS) {
159 address entry;
160 // Compute complete JNI name for style
161 stringStream st;
162 if (os_style) os::print_jni_name_prefix_on(&st, args_size);
163 st.print_raw(pure_name);
164 st.print_raw(long_name);
165 if (os_style) os::print_jni_name_suffix_on(&st, args_size);
166 char* jni_name = st.as_string();
167
168 // If the loader is null we have a system class, so we attempt a lookup in
169 // the native Java library. This takes care of any bootstrapping problems.
170 // Note: It is critical for bootstrapping that Java_java_lang_ClassLoader_00024NativeLibrary_find
171 // gets found the first time around - otherwise an infinite loop can occure. This is
172 // another VM/library dependency
173 Handle loader(THREAD, method->method_holder()->class_loader());
174 if (loader.is_null()) {
175 entry = lookup_special_native(jni_name);
176 if (entry == NULL) {
177 entry = (address) os::dll_lookup(os::native_java_library(), jni_name);
178 }
179 if (entry != NULL) {
180 in_base_library = true;
181 return entry;
182 }
183 }
184
185 // Otherwise call static method findNative in ClassLoader
186 KlassHandle klass (THREAD, SystemDictionary::ClassLoader_klass());
187 Handle name_arg = java_lang_String::create_from_str(jni_name, CHECK_NULL);
188
189 JavaValue result(T_LONG);
190 JavaCalls::call_static(&result,
191 klass,
192 vmSymbols::findNative_name(),
193 vmSymbols::classloader_string_long_signature(),
194 // Arguments
195 loader,
196 name_arg,
197 CHECK_NULL);
198 entry = (address) (intptr_t) result.get_jlong();
199
200 if (entry == NULL) {
201 // findNative didn't find it, if there are any agent libraries look in them
202 AgentLibrary* agent;
203 for (agent = Arguments::agents(); agent != NULL; agent = agent->next()) {
204 entry = (address) os::dll_lookup(agent->os_lib(), jni_name);
205 if (entry != NULL) {
206 return entry;
207 }
208 }
209 }
210
211 return entry;
212 }
213
214
215 address NativeLookup::lookup_critical_style(methodHandle method, char* pure_name, const char* long_name, int args_size, bool os_style) {
216 if (!method->has_native_function()) {
217 return NULL;
218 }
219
220 address current_entry = method->native_function();
221
222 char dll_name[JVM_MAXPATHLEN];
223 int offset;
224 if (os::dll_address_to_library_name(current_entry, dll_name, sizeof(dll_name), &offset)) {
225 char ebuf[32];
226 void* dll = os::dll_load(dll_name, ebuf, sizeof(ebuf));
227 if (dll != NULL) {
228 // Compute complete JNI name for style
229 stringStream st;
230 if (os_style) os::print_jni_name_prefix_on(&st, args_size);
231 st.print_raw(pure_name);
232 st.print_raw(long_name);
233 if (os_style) os::print_jni_name_suffix_on(&st, args_size);
234 char* jni_name = st.as_string();
235 return (address)os::dll_lookup(dll, jni_name);
236 }
237 }
238
239 return NULL;
240 }
241
242
243 // Check all the formats of native implementation name to see if there is one
244 // for the specified method.
245 address NativeLookup::lookup_entry(methodHandle method, bool& in_base_library, TRAPS) {
246 address entry = NULL;
247 in_base_library = false;
248 // Compute pure name
249 char* pure_name = pure_jni_name(method);
250
251 // Compute argument size
252 int args_size = 1 // JNIEnv
253 + (method->is_static() ? 1 : 0) // class for static methods
254 + method->size_of_parameters(); // actual parameters
255
256
257 // 1) Try JNI short style
258 entry = lookup_style(method, pure_name, "", args_size, true, in_base_library, CHECK_NULL);
259 if (entry != NULL) return entry;
260
261 // Compute long name
262 char* long_name = long_jni_name(method);
263
264 // 2) Try JNI long style
265 entry = lookup_style(method, pure_name, long_name, args_size, true, in_base_library, CHECK_NULL);
266 if (entry != NULL) return entry;
267
268 // 3) Try JNI short style without os prefix/suffix
269 entry = lookup_style(method, pure_name, "", args_size, false, in_base_library, CHECK_NULL);
270 if (entry != NULL) return entry;
271
272 // 4) Try JNI long style without os prefix/suffix
273 entry = lookup_style(method, pure_name, long_name, args_size, false, in_base_library, CHECK_NULL);
274
275 return entry; // NULL indicates not found
276 }
277
278 // Check all the formats of native implementation name to see if there is one
279 // for the specified method.
280 address NativeLookup::lookup_critical_entry(methodHandle method) {
281 if (!CriticalJNINatives) return NULL;
282
283 if (method->is_synchronized() ||
284 !method->is_static()) {
285 // Only static non-synchronized methods are allowed
286 return NULL;
287 }
288
289 ResourceMark rm;
290 address entry = NULL;
291
292 Symbol* signature = method->signature();
293 for (int end = 0; end < signature->utf8_length(); end++) {
294 if (signature->byte_at(end) == 'L') {
295 // Don't allow object types
296 return NULL;
297 }
298 }
299
300 // Compute critical name
301 char* critical_name = critical_jni_name(method);
302
303 // Compute argument size
304 int args_size = 1 // JNIEnv
305 + (method->is_static() ? 1 : 0) // class for static methods
306 + method->size_of_parameters(); // actual parameters
307
308
309 // 1) Try JNI short style
310 entry = lookup_critical_style(method, critical_name, "", args_size, true);
311 if (entry != NULL) return entry;
312
313 // Compute long name
314 char* long_name = long_jni_name(method);
315
316 // 2) Try JNI long style
317 entry = lookup_critical_style(method, critical_name, long_name, args_size, true);
318 if (entry != NULL) return entry;
319
320 // 3) Try JNI short style without os prefix/suffix
321 entry = lookup_critical_style(method, critical_name, "", args_size, false);
322 if (entry != NULL) return entry;
323
324 // 4) Try JNI long style without os prefix/suffix
325 entry = lookup_critical_style(method, critical_name, long_name, args_size, false);
326
327 return entry; // NULL indicates not found
328 }
329
330 // Check if there are any JVM TI prefixes which have been applied to the native method name.
331 // If any are found, remove them before attemping the look up of the
332 // native implementation again.
333 // See SetNativeMethodPrefix in the JVM TI Spec for more details.
334 address NativeLookup::lookup_entry_prefixed(methodHandle method, bool& in_base_library, TRAPS) {
335 #if INCLUDE_JVMTI
336 ResourceMark rm(THREAD);
337
338 int prefix_count;
339 char** prefixes = JvmtiExport::get_all_native_method_prefixes(&prefix_count);
340 char* in_name = method->name()->as_C_string();
341 char* wrapper_name = in_name;
342 // last applied prefix will be first -- go backwards
343 for (int i = prefix_count-1; i >= 0; i--) {
344 char* prefix = prefixes[i];
345 size_t prefix_len = strlen(prefix);
346 if (strncmp(prefix, wrapper_name, prefix_len) == 0) {
347 // has this prefix remove it
348 wrapper_name += prefix_len;
349 }
350 }
351 if (wrapper_name != in_name) {
352 // we have a name for a wrapping method
353 int wrapper_name_len = (int)strlen(wrapper_name);
354 TempNewSymbol wrapper_symbol = SymbolTable::probe(wrapper_name, wrapper_name_len);
355 if (wrapper_symbol != NULL) {
356 KlassHandle kh(method->method_holder());
357 Method* wrapper_method = kh()->lookup_method(wrapper_symbol,
358 method->signature());
359 if (wrapper_method != NULL && !wrapper_method->is_native()) {
360 // we found a wrapper method, use its native entry
361 method->set_is_prefixed_native();
362 return lookup_entry(wrapper_method, in_base_library, THREAD);
363 }
364 }
365 }
366 #endif // INCLUDE_JVMTI
367 return NULL;
368 }
369
370 address NativeLookup::lookup_base(methodHandle method, bool& in_base_library, TRAPS) {
371 address entry = NULL;
372 ResourceMark rm(THREAD);
373
374 entry = lookup_entry(method, in_base_library, THREAD);
375 if (entry != NULL) return entry;
376
377 // standard native method resolution has failed. Check if there are any
378 // JVM TI prefixes which have been applied to the native method name.
379 entry = lookup_entry_prefixed(method, in_base_library, THREAD);
380 if (entry != NULL) return entry;
381
382 // Native function not found, throw UnsatisfiedLinkError
383 THROW_MSG_0(vmSymbols::java_lang_UnsatisfiedLinkError(),
384 method->name_and_sig_as_C_string());
385 }
386
387
388 address NativeLookup::lookup(methodHandle method, bool& in_base_library, TRAPS) {
389 if (!method->has_native_function()) {
390 address entry = lookup_base(method, in_base_library, CHECK_NULL);
391 method->set_native_function(entry,
392 Method::native_bind_event_is_interesting);
393 // -verbose:jni printing
394 if (PrintJNIResolving) {
395 ResourceMark rm(THREAD);
396 tty->print_cr("[Dynamic-linking native method %s.%s ... JNI]",
397 method->method_holder()->external_name(),
398 method->name()->as_C_string());
399 }
400 }
401 return method->native_function();
402 }
403
404 address NativeLookup::base_library_lookup(const char* class_name, const char* method_name, const char* signature) {
405 EXCEPTION_MARK;
406 bool in_base_library = true; // SharedRuntime inits some math methods.
407 TempNewSymbol c_name = SymbolTable::new_symbol(class_name, CATCH);
408 TempNewSymbol m_name = SymbolTable::new_symbol(method_name, CATCH);
409 TempNewSymbol s_name = SymbolTable::new_symbol(signature, CATCH);
410
411 // Find the class
412 Klass* k = SystemDictionary::resolve_or_fail(c_name, true, CATCH);
413 instanceKlassHandle klass (THREAD, k);
414
415 // Find method and invoke standard lookup
416 methodHandle method (THREAD,
417 klass->uncached_lookup_method(m_name, s_name, Klass::find_overpass));
418 address result = lookup(method, in_base_library, CATCH);
419 assert(in_base_library, "must be in basic library");
420 guarantee(result != NULL, "must be non NULL");
421 return result;
422 }