1 /*
2 * Copyright (C) 2014 The Android Open Source Project
3 *
4 * Licensed under the Apache License, Version 2.0 (the "License");
5 * you may not use this file except in compliance with the License.
6 * You may obtain a copy of the License at
7 *
8 * http://www.apache.org/licenses/LICENSE-2.0
9 *
10 * Unless required by applicable law or agreed to in writing, software
11 * distributed under the License is distributed on an "AS IS" BASIS,
12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13 * See the License for the specific language governing permissions and
14 * limitations under the License.
15 */
16
17 // A simple implementation of the native-bridge interface.
18
19 #include <algorithm>
20 #include <dlfcn.h>
21 #include <jni.h>
22 #include <stdlib.h>
23 #include <signal.h>
24 #include <vector>
25
26 #include "stdio.h"
27 #include "unistd.h"
28 #include "sys/stat.h"
29
30 #include "base/macros.h"
31 #include "nativebridge/native_bridge.h"
32
33 struct NativeBridgeMethod {
34 const char* name;
35 const char* signature;
36 bool static_method;
37 void* fnPtr;
38 void* trampoline;
39 };
40
41 static NativeBridgeMethod* find_native_bridge_method(const char *name);
42 static const android::NativeBridgeRuntimeCallbacks* gNativeBridgeArtCallbacks;
43
trampoline_JNI_OnLoad(JavaVM * vm,void * reserved)44 static jint trampoline_JNI_OnLoad(JavaVM* vm, void* reserved) {
45 JNIEnv* env = nullptr;
46 typedef jint (*FnPtr_t)(JavaVM*, void*);
47 FnPtr_t fnPtr = reinterpret_cast<FnPtr_t>(find_native_bridge_method("JNI_OnLoad")->fnPtr);
48
49 vm->GetEnv(reinterpret_cast<void **>(&env), JNI_VERSION_1_6);
50 if (env == nullptr) {
51 return 0;
52 }
53
54 jclass klass = env->FindClass("Main");
55 if (klass != nullptr) {
56 int i, count1, count2;
57 count1 = gNativeBridgeArtCallbacks->getNativeMethodCount(env, klass);
58 std::unique_ptr<JNINativeMethod[]> methods(new JNINativeMethod[count1]);
59 if (methods == nullptr) {
60 return 0;
61 }
62 count2 = gNativeBridgeArtCallbacks->getNativeMethods(env, klass, methods.get(), count1);
63 if (count1 == count2) {
64 printf("Test ART callbacks: all JNI function number is %d.\n", count1);
65 }
66
67 for (i = 0; i < count1; i++) {
68 NativeBridgeMethod* nb_method = find_native_bridge_method(methods[i].name);
69 if (nb_method != nullptr) {
70 jmethodID mid = nullptr;
71 if (nb_method->static_method) {
72 mid = env->GetStaticMethodID(klass, methods[i].name, nb_method->signature);
73 } else {
74 mid = env->GetMethodID(klass, methods[i].name, nb_method->signature);
75 }
76 if (mid != nullptr) {
77 const char* shorty = gNativeBridgeArtCallbacks->getMethodShorty(env, mid);
78 if (strcmp(shorty, methods[i].signature) == 0) {
79 printf(" name:%s, signature:%s, shorty:%s.\n",
80 methods[i].name, nb_method->signature, shorty);
81 }
82 }
83 }
84 }
85 methods.release();
86 }
87
88 printf("%s called!\n", __FUNCTION__);
89 return fnPtr(vm, reserved);
90 }
91
trampoline_Java_Main_testFindClassOnAttachedNativeThread(JNIEnv * env,jclass klass)92 static void trampoline_Java_Main_testFindClassOnAttachedNativeThread(JNIEnv* env,
93 jclass klass) {
94 typedef void (*FnPtr_t)(JNIEnv*, jclass);
95 FnPtr_t fnPtr = reinterpret_cast<FnPtr_t>
96 (find_native_bridge_method("testFindClassOnAttachedNativeThread")->fnPtr);
97 printf("%s called!\n", __FUNCTION__);
98 return fnPtr(env, klass);
99 }
100
trampoline_Java_Main_testFindFieldOnAttachedNativeThreadNative(JNIEnv * env,jclass klass)101 static void trampoline_Java_Main_testFindFieldOnAttachedNativeThreadNative(JNIEnv* env,
102 jclass klass) {
103 typedef void (*FnPtr_t)(JNIEnv*, jclass);
104 FnPtr_t fnPtr = reinterpret_cast<FnPtr_t>
105 (find_native_bridge_method("testFindFieldOnAttachedNativeThreadNative")->fnPtr);
106 printf("%s called!\n", __FUNCTION__);
107 return fnPtr(env, klass);
108 }
109
trampoline_Java_Main_testCallStaticVoidMethodOnSubClassNative(JNIEnv * env,jclass klass)110 static void trampoline_Java_Main_testCallStaticVoidMethodOnSubClassNative(JNIEnv* env,
111 jclass klass) {
112 typedef void (*FnPtr_t)(JNIEnv*, jclass);
113 FnPtr_t fnPtr = reinterpret_cast<FnPtr_t>
114 (find_native_bridge_method("testCallStaticVoidMethodOnSubClassNative")->fnPtr);
115 printf("%s called!\n", __FUNCTION__);
116 return fnPtr(env, klass);
117 }
118
trampoline_Java_Main_testGetMirandaMethodNative(JNIEnv * env,jclass klass)119 static jobject trampoline_Java_Main_testGetMirandaMethodNative(JNIEnv* env, jclass klass) {
120 typedef jobject (*FnPtr_t)(JNIEnv*, jclass);
121 FnPtr_t fnPtr = reinterpret_cast<FnPtr_t>
122 (find_native_bridge_method("testGetMirandaMethodNative")->fnPtr);
123 printf("%s called!\n", __FUNCTION__);
124 return fnPtr(env, klass);
125 }
126
trampoline_Java_Main_testNewStringObject(JNIEnv * env,jclass klass)127 static void trampoline_Java_Main_testNewStringObject(JNIEnv* env, jclass klass) {
128 typedef void (*FnPtr_t)(JNIEnv*, jclass);
129 FnPtr_t fnPtr = reinterpret_cast<FnPtr_t>
130 (find_native_bridge_method("testNewStringObject")->fnPtr);
131 printf("%s called!\n", __FUNCTION__);
132 return fnPtr(env, klass);
133 }
134
trampoline_Java_Main_testZeroLengthByteBuffers(JNIEnv * env,jclass klass)135 static void trampoline_Java_Main_testZeroLengthByteBuffers(JNIEnv* env, jclass klass) {
136 typedef void (*FnPtr_t)(JNIEnv*, jclass);
137 FnPtr_t fnPtr = reinterpret_cast<FnPtr_t>
138 (find_native_bridge_method("testZeroLengthByteBuffers")->fnPtr);
139 printf("%s called!\n", __FUNCTION__);
140 return fnPtr(env, klass);
141 }
142
trampoline_Java_Main_byteMethod(JNIEnv * env,jclass klass,jbyte b1,jbyte b2,jbyte b3,jbyte b4,jbyte b5,jbyte b6,jbyte b7,jbyte b8,jbyte b9,jbyte b10)143 static jbyte trampoline_Java_Main_byteMethod(JNIEnv* env, jclass klass, jbyte b1, jbyte b2,
144 jbyte b3, jbyte b4, jbyte b5, jbyte b6,
145 jbyte b7, jbyte b8, jbyte b9, jbyte b10) {
146 typedef jbyte (*FnPtr_t)(JNIEnv*, jclass, jbyte, jbyte, jbyte, jbyte, jbyte,
147 jbyte, jbyte, jbyte, jbyte, jbyte);
148 FnPtr_t fnPtr = reinterpret_cast<FnPtr_t>(find_native_bridge_method("byteMethod")->fnPtr);
149 printf("%s called!\n", __FUNCTION__);
150 return fnPtr(env, klass, b1, b2, b3, b4, b5, b6, b7, b8, b9, b10);
151 }
152
trampoline_Java_Main_shortMethod(JNIEnv * env,jclass klass,jshort s1,jshort s2,jshort s3,jshort s4,jshort s5,jshort s6,jshort s7,jshort s8,jshort s9,jshort s10)153 static jshort trampoline_Java_Main_shortMethod(JNIEnv* env, jclass klass, jshort s1, jshort s2,
154 jshort s3, jshort s4, jshort s5, jshort s6,
155 jshort s7, jshort s8, jshort s9, jshort s10) {
156 typedef jshort (*FnPtr_t)(JNIEnv*, jclass, jshort, jshort, jshort, jshort, jshort,
157 jshort, jshort, jshort, jshort, jshort);
158 FnPtr_t fnPtr = reinterpret_cast<FnPtr_t>(find_native_bridge_method("shortMethod")->fnPtr);
159 printf("%s called!\n", __FUNCTION__);
160 return fnPtr(env, klass, s1, s2, s3, s4, s5, s6, s7, s8, s9, s10);
161 }
162
trampoline_Java_Main_booleanMethod(JNIEnv * env,jclass klass,jboolean b1,jboolean b2,jboolean b3,jboolean b4,jboolean b5,jboolean b6,jboolean b7,jboolean b8,jboolean b9,jboolean b10)163 static jboolean trampoline_Java_Main_booleanMethod(JNIEnv* env, jclass klass, jboolean b1,
164 jboolean b2, jboolean b3, jboolean b4,
165 jboolean b5, jboolean b6, jboolean b7,
166 jboolean b8, jboolean b9, jboolean b10) {
167 typedef jboolean (*FnPtr_t)(JNIEnv*, jclass, jboolean, jboolean, jboolean, jboolean, jboolean,
168 jboolean, jboolean, jboolean, jboolean, jboolean);
169 FnPtr_t fnPtr = reinterpret_cast<FnPtr_t>(find_native_bridge_method("booleanMethod")->fnPtr);
170 printf("%s called!\n", __FUNCTION__);
171 return fnPtr(env, klass, b1, b2, b3, b4, b5, b6, b7, b8, b9, b10);
172 }
173
trampoline_Java_Main_charMethod(JNIEnv * env,jclass klass,jchar c1,jchar c2,jchar c3,jchar c4,jchar c5,jchar c6,jchar c7,jchar c8,jchar c9,jchar c10)174 static jchar trampoline_Java_Main_charMethod(JNIEnv* env, jclass klass, jchar c1, jchar c2,
175 jchar c3, jchar c4, jchar c5, jchar c6,
176 jchar c7, jchar c8, jchar c9, jchar c10) {
177 typedef jchar (*FnPtr_t)(JNIEnv*, jclass, jchar, jchar, jchar, jchar, jchar,
178 jchar, jchar, jchar, jchar, jchar);
179 FnPtr_t fnPtr = reinterpret_cast<FnPtr_t>(find_native_bridge_method("charMethod")->fnPtr);
180 printf("%s called!\n", __FUNCTION__);
181 return fnPtr(env, klass, c1, c2, c3, c4, c5, c6, c7, c8, c9, c10);
182 }
183
184 // This code is adapted from 004-SignalTest and causes a segfault.
185 char *go_away_compiler = nullptr;
186
test_sigaction_handler(int sig ATTRIBUTE_UNUSED,siginfo_t * info ATTRIBUTE_UNUSED,void * context ATTRIBUTE_UNUSED)187 [[ noreturn ]] static void test_sigaction_handler(int sig ATTRIBUTE_UNUSED,
188 siginfo_t* info ATTRIBUTE_UNUSED,
189 void* context ATTRIBUTE_UNUSED) {
190 printf("Should not reach the test sigaction handler.");
191 abort();
192 }
193
trampoline_Java_Main_testSignal(JNIEnv *,jclass)194 static jint trampoline_Java_Main_testSignal(JNIEnv*, jclass) {
195 // Install the sigaction handler above, which should *not* be reached as the native-bridge
196 // handler should be called first. Note: we won't chain at all, if we ever get here, we'll die.
197 struct sigaction tmp;
198 sigemptyset(&tmp.sa_mask);
199 tmp.sa_sigaction = test_sigaction_handler;
200 #if !defined(__APPLE__) && !defined(__mips__)
201 tmp.sa_restorer = nullptr;
202 #endif
203 sigaction(SIGSEGV, &tmp, nullptr);
204
205 #if defined(__arm__) || defined(__i386__) || defined(__x86_64__) || defined(__aarch64__)
206 // On supported architectures we cause a real SEGV.
207 *go_away_compiler = 'a';
208 #else
209 // On other architectures we simulate SEGV.
210 kill(getpid(), SIGSEGV);
211 #endif
212 return 1234;
213 }
214
215 NativeBridgeMethod gNativeBridgeMethods[] = {
216 { "JNI_OnLoad", "", true, nullptr,
217 reinterpret_cast<void*>(trampoline_JNI_OnLoad) },
218 { "booleanMethod", "(ZZZZZZZZZZ)Z", true, nullptr,
219 reinterpret_cast<void*>(trampoline_Java_Main_booleanMethod) },
220 { "byteMethod", "(BBBBBBBBBB)B", true, nullptr,
221 reinterpret_cast<void*>(trampoline_Java_Main_byteMethod) },
222 { "charMethod", "(CCCCCCCCCC)C", true, nullptr,
223 reinterpret_cast<void*>(trampoline_Java_Main_charMethod) },
224 { "shortMethod", "(SSSSSSSSSS)S", true, nullptr,
225 reinterpret_cast<void*>(trampoline_Java_Main_shortMethod) },
226 { "testCallStaticVoidMethodOnSubClassNative", "()V", true, nullptr,
227 reinterpret_cast<void*>(trampoline_Java_Main_testCallStaticVoidMethodOnSubClassNative) },
228 { "testFindClassOnAttachedNativeThread", "()V", true, nullptr,
229 reinterpret_cast<void*>(trampoline_Java_Main_testFindClassOnAttachedNativeThread) },
230 { "testFindFieldOnAttachedNativeThreadNative", "()V", true, nullptr,
231 reinterpret_cast<void*>(trampoline_Java_Main_testFindFieldOnAttachedNativeThreadNative) },
232 { "testGetMirandaMethodNative", "()Ljava/lang/reflect/Method;", true, nullptr,
233 reinterpret_cast<void*>(trampoline_Java_Main_testGetMirandaMethodNative) },
234 { "testNewStringObject", "()V", true, nullptr,
235 reinterpret_cast<void*>(trampoline_Java_Main_testNewStringObject) },
236 { "testZeroLengthByteBuffers", "()V", true, nullptr,
237 reinterpret_cast<void*>(trampoline_Java_Main_testZeroLengthByteBuffers) },
238 { "testSignal", "()I", true, nullptr,
239 reinterpret_cast<void*>(trampoline_Java_Main_testSignal) },
240 };
241
find_native_bridge_method(const char * name)242 static NativeBridgeMethod* find_native_bridge_method(const char *name) {
243 const char* pname = name;
244 if (strncmp(name, "Java_Main_", 10) == 0) {
245 pname += 10;
246 }
247
248 for (size_t i = 0; i < sizeof(gNativeBridgeMethods) / sizeof(gNativeBridgeMethods[0]); i++) {
249 if (strcmp(pname, gNativeBridgeMethods[i].name) == 0) {
250 return &gNativeBridgeMethods[i];
251 }
252 }
253 return nullptr;
254 }
255
256 // NativeBridgeCallbacks implementations
native_bridge_initialize(const android::NativeBridgeRuntimeCallbacks * art_cbs,const char * app_code_cache_dir,const char * isa ATTRIBUTE_UNUSED)257 extern "C" bool native_bridge_initialize(const android::NativeBridgeRuntimeCallbacks* art_cbs,
258 const char* app_code_cache_dir,
259 const char* isa ATTRIBUTE_UNUSED) {
260 struct stat st;
261 if ((app_code_cache_dir != nullptr)
262 && (stat(app_code_cache_dir, &st) == 0)
263 && S_ISDIR(st.st_mode)) {
264 printf("Code cache exists: '%s'.\n", app_code_cache_dir);
265 }
266 if (art_cbs != nullptr) {
267 gNativeBridgeArtCallbacks = art_cbs;
268 printf("Native bridge initialized.\n");
269 }
270 return true;
271 }
272
native_bridge_loadLibrary(const char * libpath,int flag)273 extern "C" void* native_bridge_loadLibrary(const char* libpath, int flag) {
274 size_t len = strlen(libpath);
275 char* tmp = new char[len + 10];
276 strncpy(tmp, libpath, len);
277 tmp[len - 3] = '2';
278 tmp[len - 2] = '.';
279 tmp[len - 1] = 's';
280 tmp[len] = 'o';
281 tmp[len + 1] = 0;
282 void* handle = dlopen(tmp, flag);
283 delete[] tmp;
284
285 if (handle == nullptr) {
286 printf("Handle = nullptr!\n");
287 printf("Was looking for %s.\n", libpath);
288 printf("Error = %s.\n", dlerror());
289 char cwd[1024];
290 if (getcwd(cwd, sizeof(cwd)) != nullptr) {
291 printf("Current working dir: %s\n", cwd);
292 }
293 }
294 return handle;
295 }
296
native_bridge_getTrampoline(void * handle,const char * name,const char * shorty,uint32_t len ATTRIBUTE_UNUSED)297 extern "C" void* native_bridge_getTrampoline(void* handle, const char* name, const char* shorty,
298 uint32_t len ATTRIBUTE_UNUSED) {
299 printf("Getting trampoline for %s with shorty %s.\n", name, shorty);
300
301 // The name here is actually the JNI name, so we can directly do the lookup.
302 void* sym = dlsym(handle, name);
303 NativeBridgeMethod* method = find_native_bridge_method(name);
304 if (method == nullptr)
305 return nullptr;
306 method->fnPtr = sym;
307
308 return method->trampoline;
309 }
310
native_bridge_isSupported(const char * libpath)311 extern "C" bool native_bridge_isSupported(const char* libpath) {
312 printf("Checking for support.\n");
313
314 if (libpath == nullptr) {
315 return false;
316 }
317 // We don't want to hijack javacore. So we should get libarttest...
318 return strcmp(libpath, "libjavacore.so") != 0;
319 }
320
321 namespace android {
322
323 // Environment values required by the apps running with native bridge.
324 struct NativeBridgeRuntimeValues {
325 const char* os_arch;
326 const char* cpu_abi;
327 const char* cpu_abi2;
328 const char* *supported_abis;
329 int32_t abi_count;
330 };
331
332 } // namespace android
333
334 const char* supported_abis[] = {
335 "supported1", "supported2", "supported3"
336 };
337
338 const struct android::NativeBridgeRuntimeValues nb_env {
339 .os_arch = "os.arch",
340 .cpu_abi = "cpu_abi",
341 .cpu_abi2 = "cpu_abi2",
342 .supported_abis = supported_abis,
343 .abi_count = 3
344 };
345
native_bridge_getAppEnv(const char * abi)346 extern "C" const struct android::NativeBridgeRuntimeValues* native_bridge_getAppEnv(
347 const char* abi) {
348 printf("Checking for getEnvValues.\n");
349
350 if (abi == nullptr) {
351 return nullptr;
352 }
353
354 return &nb_env;
355 }
356
357 // v2 parts.
358
nb_is_compatible(uint32_t bridge_version ATTRIBUTE_UNUSED)359 extern "C" bool nb_is_compatible(uint32_t bridge_version ATTRIBUTE_UNUSED) {
360 return true;
361 }
362
363 #if defined(__i386__) || defined(__x86_64__)
364 #if defined(__APPLE__)
365 #define ucontext __darwin_ucontext
366
367 #if defined(__x86_64__)
368 // 64 bit mac build.
369 #define CTX_EIP uc_mcontext->__ss.__rip
370 #else
371 // 32 bit mac build.
372 #define CTX_EIP uc_mcontext->__ss.__eip
373 #endif
374
375 #elif defined(__x86_64__)
376 // 64 bit linux build.
377 #define CTX_EIP uc_mcontext.gregs[REG_RIP]
378 #else
379 // 32 bit linux build.
380 #define CTX_EIP uc_mcontext.gregs[REG_EIP]
381 #endif
382 #endif
383
384 // A dummy special handler, continueing after the faulting location. This code comes from
385 // 004-SignalTest.
nb_signalhandler(int sig,siginfo_t * info ATTRIBUTE_UNUSED,void * context)386 static bool nb_signalhandler(int sig, siginfo_t* info ATTRIBUTE_UNUSED, void* context) {
387 printf("NB signal handler with signal %d.\n", sig);
388 #if defined(__arm__)
389 struct ucontext *uc = reinterpret_cast<struct ucontext*>(context);
390 struct sigcontext *sc = reinterpret_cast<struct sigcontext*>(&uc->uc_mcontext);
391 sc->arm_pc += 2; // Skip instruction causing segv.
392 #elif defined(__aarch64__)
393 struct ucontext *uc = reinterpret_cast<struct ucontext*>(context);
394 struct sigcontext *sc = reinterpret_cast<struct sigcontext*>(&uc->uc_mcontext);
395 sc->pc += 4; // Skip instruction causing segv.
396 #elif defined(__i386__) || defined(__x86_64__)
397 struct ucontext *uc = reinterpret_cast<struct ucontext*>(context);
398 uc->CTX_EIP += 3;
399 #else
400 UNUSED(context);
401 #endif
402 // We handled this...
403 return true;
404 }
405
native_bridge_get_signal_handler(int signal)406 static ::android::NativeBridgeSignalHandlerFn native_bridge_get_signal_handler(int signal) {
407 // Only test segfault handler.
408 if (signal == SIGSEGV) {
409 return &nb_signalhandler;
410 }
411 return nullptr;
412 }
413
414
415 // "NativeBridgeItf" is effectively an API (it is the name of the symbol that will be loaded
416 // by the native bridge library).
417 android::NativeBridgeCallbacks NativeBridgeItf {
418 .version = 2,
419 .initialize = &native_bridge_initialize,
420 .loadLibrary = &native_bridge_loadLibrary,
421 .getTrampoline = &native_bridge_getTrampoline,
422 .isSupported = &native_bridge_isSupported,
423 .getAppEnv = &native_bridge_getAppEnv,
424 .isCompatibleWith = &nb_is_compatible,
425 .getSignalHandler = &native_bridge_get_signal_handler
426 };
427