1 /* This Source Code Form is subject to the terms of the Mozilla Public
2  * License, v. 2.0. If a copy of the MPL was not distributed with this
3  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
4 
5 /*
6  * This custom library loading code is only meant to be called
7  * during initialization. As a result, it takes no special
8  * precautions to be threadsafe. Any of the library loading functions
9  * like mozload should not be available to other code.
10  */
11 
12 #include <jni.h>
13 #include <android/log.h>
14 #include <sys/types.h>
15 #include <sys/stat.h>
16 #include <sys/mman.h>
17 #include <sys/limits.h>
18 #include <errno.h>
19 #include <string.h>
20 #include <stdio.h>
21 #include <stdlib.h>
22 #include <fcntl.h>
23 #include <unistd.h>
24 #include <zlib.h>
25 #include "dlfcn.h"
26 #include "APKOpen.h"
27 #include <sys/time.h>
28 #include <sys/syscall.h>
29 #include <sys/resource.h>
30 #include <sys/prctl.h>
31 #include "sqlite3.h"
32 #include "Linker.h"
33 #include "BaseProfiler.h"
34 #include "application.ini.h"
35 
36 #include "mozilla/arm.h"
37 #include "mozilla/Bootstrap.h"
38 #include "mozilla/Printf.h"
39 #include "mozilla/Sprintf.h"
40 #include "mozilla/TimeStamp.h"
41 #include "mozilla/UniquePtr.h"
42 #include "XREChildData.h"
43 
44 /* Android headers don't define RUSAGE_THREAD */
45 #ifndef RUSAGE_THREAD
46 #  define RUSAGE_THREAD 1
47 #endif
48 
49 #ifndef RELEASE_OR_BETA
50 /* Official builds have the debuggable flag set to false, which disables
51  * the backtrace dumper from bionic. However, as it is useful for native
52  * crashes happening before the crash reporter is registered, re-enable
53  * it on non release builds (i.e. nightly and aurora).
54  * Using a constructor so that it is re-enabled as soon as libmozglue.so
55  * is loaded.
56  */
make_dumpable()57 __attribute__((constructor)) void make_dumpable() { prctl(PR_SET_DUMPABLE, 1); }
58 #endif
59 
60 typedef int mozglueresult;
61 
62 using LoadGeckoLibsResult =
63     mozilla::Result<mozilla::Ok, mozilla::BootstrapError>;
64 
65 enum StartupEvent {
66 #define mozilla_StartupTimeline_Event(ev, z) ev,
67 #include "StartupTimeline.h"
68 #undef mozilla_StartupTimeline_Event
69   MAX_STARTUP_EVENT_ID
70 };
71 
72 using namespace mozilla;
73 
JNI_Throw(JNIEnv * jenv,const char * classname,const char * msg)74 void JNI_Throw(JNIEnv* jenv, const char* classname, const char* msg) {
75   __android_log_print(ANDROID_LOG_ERROR, "GeckoLibLoad", "Throw\n");
76   jclass cls = jenv->FindClass(classname);
77   if (cls == nullptr) {
78     __android_log_print(
79         ANDROID_LOG_ERROR, "GeckoLibLoad",
80         "Couldn't find exception class (or exception pending) %s\n", classname);
81     exit(FAILURE);
82   }
83   int rc = jenv->ThrowNew(cls, msg);
84   if (rc < 0) {
85     __android_log_print(ANDROID_LOG_ERROR, "GeckoLibLoad",
86                         "Error throwing exception %s\n", msg);
87     exit(FAILURE);
88   }
89   jenv->DeleteLocalRef(cls);
90 }
91 
92 namespace {
93 JavaVM* sJavaVM;
94 }
95 
abortThroughJava(const char * msg)96 void abortThroughJava(const char* msg) {
97   struct sigaction sigact = {};
98   if (__wrap_sigaction(SIGSEGV, nullptr, &sigact)) {
99     return;  // sigaction call failed.
100   }
101 
102   Dl_info info = {};
103   if ((sigact.sa_flags & SA_SIGINFO) &&
104       __wrap_dladdr(reinterpret_cast<void*>(sigact.sa_sigaction), &info) &&
105       info.dli_fname && strstr(info.dli_fname, "libxul.so")) {
106     return;  // Existing signal handler is in libxul (i.e. we have crash
107              // reporter).
108   }
109 
110   JNIEnv* env = nullptr;
111   if (!sJavaVM ||
112       sJavaVM->AttachCurrentThreadAsDaemon(&env, nullptr) != JNI_OK) {
113     return;
114   }
115 
116   if (!env || env->PushLocalFrame(2) != JNI_OK) {
117     return;
118   }
119 
120   jclass loader = env->FindClass("org/mozilla/gecko/mozglue/GeckoLoader");
121   if (!loader) {
122     return;
123   }
124 
125   jmethodID method =
126       env->GetStaticMethodID(loader, "abort", "(Ljava/lang/String;)V");
127   jstring str = env->NewStringUTF(msg);
128 
129   if (method && str) {
130     env->CallStaticVoidMethod(loader, method, str);
131   }
132 
133   env->PopLocalFrame(nullptr);
134 }
135 
136 Bootstrap::UniquePtr gBootstrap;
137 #ifndef MOZ_FOLD_LIBS
138 static void* sqlite_handle = nullptr;
139 static void* nspr_handle = nullptr;
140 static void* plc_handle = nullptr;
141 #else
142 #  define sqlite_handle nss_handle
143 #  define nspr_handle nss_handle
144 #  define plc_handle nss_handle
145 #endif
146 static void* nss_handle = nullptr;
147 
getUnpackedLibraryName(const char * libraryName)148 static UniquePtr<char[]> getUnpackedLibraryName(const char* libraryName) {
149   static const char* libdir = getenv("MOZ_ANDROID_LIBDIR");
150 
151   size_t len = strlen(libdir) + 1 /* path separator */ + strlen(libraryName) +
152                1; /* null terminator */
153   auto file = MakeUnique<char[]>(len);
154   snprintf(file.get(), len, "%s/%s", libdir, libraryName);
155   return file;
156 }
157 
dlopenLibrary(const char * libraryName)158 static void* dlopenLibrary(const char* libraryName) {
159   return __wrap_dlopen(getUnpackedLibraryName(libraryName).get(),
160                        RTLD_GLOBAL | RTLD_LAZY);
161 }
162 
EnsureBaseProfilerInitialized()163 static void EnsureBaseProfilerInitialized() {
164   // There is no single entry-point into C++ code on Android.
165   // Instead, GeckoThread and GeckoLibLoader call various functions to load
166   // libraries one-by-one.
167   // We want to capture all that library loading in the profiler, so we need to
168   // kick off the base profiler at the beginning of whichever function is called
169   // first.
170   // We currently assume that all these functions are called on the same thread.
171   static bool sInitialized = false;
172   if (sInitialized) {
173     return;
174   }
175 
176   // The stack depth we observe here will be determined by the stack of
177   // whichever caller enters this code first. In practice this means that we may
178   // miss some root-most frames, which hopefully shouldn't ruin profiling.
179   int stackBase = 5;
180   mozilla::baseprofiler::profiler_init(&stackBase);
181   sInitialized = true;
182 }
183 
loadGeckoLibs()184 static LoadGeckoLibsResult loadGeckoLibs() {
185   TimeStamp t0 = TimeStamp::Now();
186   struct rusage usage1_thread, usage1;
187   getrusage(RUSAGE_THREAD, &usage1_thread);
188   getrusage(RUSAGE_SELF, &usage1);
189 
190   static const char* libxul = getenv("MOZ_ANDROID_LIBDIR_OVERRIDE");
191   MOZ_TRY_VAR(
192       gBootstrap,
193       GetBootstrap(libxul ? libxul : getUnpackedLibraryName("libxul.so").get(),
194                    LibLoadingStrategy::ReadAhead));
195 
196   TimeStamp t1 = TimeStamp::Now();
197   struct rusage usage2_thread, usage2;
198   getrusage(RUSAGE_THREAD, &usage2_thread);
199   getrusage(RUSAGE_SELF, &usage2);
200 
201 #define RUSAGE_TIMEDIFF(u1, u2, field)                    \
202   ((u2.ru_##field.tv_sec - u1.ru_##field.tv_sec) * 1000 + \
203    (u2.ru_##field.tv_usec - u1.ru_##field.tv_usec) / 1000)
204 
205   __android_log_print(ANDROID_LOG_ERROR, "GeckoLibLoad",
206                       "Loaded libs in %fms total, %ldms(%ldms) user, "
207                       "%ldms(%ldms) system, %ld(%ld) faults",
208                       (t1 - t0).ToMilliseconds(),
209                       RUSAGE_TIMEDIFF(usage1_thread, usage2_thread, utime),
210                       RUSAGE_TIMEDIFF(usage1, usage2, utime),
211                       RUSAGE_TIMEDIFF(usage1_thread, usage2_thread, stime),
212                       RUSAGE_TIMEDIFF(usage1, usage2, stime),
213                       usage2_thread.ru_majflt - usage1_thread.ru_majflt,
214                       usage2.ru_majflt - usage1.ru_majflt);
215 
216   gBootstrap->XRE_StartupTimelineRecord(LINKER_INITIALIZED, t0);
217   gBootstrap->XRE_StartupTimelineRecord(LIBRARIES_LOADED, t1);
218   return Ok();
219 }
220 
221 static mozglueresult loadNSSLibs();
222 
loadSQLiteLibs()223 static mozglueresult loadSQLiteLibs() {
224   if (sqlite_handle) return SUCCESS;
225 
226 #ifdef MOZ_FOLD_LIBS
227   if (loadNSSLibs() != SUCCESS) return FAILURE;
228 #else
229 
230   sqlite_handle = dlopenLibrary("libmozsqlite3.so");
231   if (!sqlite_handle) {
232     __android_log_print(ANDROID_LOG_ERROR, "GeckoLibLoad",
233                         "Couldn't get a handle to libmozsqlite3!");
234     return FAILURE;
235   }
236 #endif
237 
238   return SUCCESS;
239 }
240 
loadNSSLibs()241 static mozglueresult loadNSSLibs() {
242   if (nss_handle && nspr_handle && plc_handle) return SUCCESS;
243 
244   nss_handle = dlopenLibrary("libnss3.so");
245 
246 #ifndef MOZ_FOLD_LIBS
247   nspr_handle = dlopenLibrary("libnspr4.so");
248 
249   plc_handle = dlopenLibrary("libplc4.so");
250 #endif
251 
252   if (!nss_handle) {
253     __android_log_print(ANDROID_LOG_ERROR, "GeckoLibLoad",
254                         "Couldn't get a handle to libnss3!");
255     return FAILURE;
256   }
257 
258 #ifndef MOZ_FOLD_LIBS
259   if (!nspr_handle) {
260     __android_log_print(ANDROID_LOG_ERROR, "GeckoLibLoad",
261                         "Couldn't get a handle to libnspr4!");
262     return FAILURE;
263   }
264 
265   if (!plc_handle) {
266     __android_log_print(ANDROID_LOG_ERROR, "GeckoLibLoad",
267                         "Couldn't get a handle to libplc4!");
268     return FAILURE;
269   }
270 #endif
271 
272   return SUCCESS;
273 }
274 
275 extern "C" APKOPEN_EXPORT void MOZ_JNICALL
Java_org_mozilla_gecko_mozglue_GeckoLoader_loadGeckoLibsNative(JNIEnv * jenv,jclass jGeckoAppShellClass)276 Java_org_mozilla_gecko_mozglue_GeckoLoader_loadGeckoLibsNative(
277     JNIEnv* jenv, jclass jGeckoAppShellClass) {
278   EnsureBaseProfilerInitialized();
279 
280   jenv->GetJavaVM(&sJavaVM);
281 
282   LoadGeckoLibsResult res = loadGeckoLibs();
283   if (res.isOk()) {
284     return;
285   }
286 
287   const BootstrapError& errorInfo = res.inspectErr();
288 
289   auto msg = errorInfo.match(
290       [](const nsresult& aRv) {
291         return Smprintf("Error loading Gecko libraries: nsresult 0x%08X", aRv);
292       },
293       [](const DLErrorType& aErr) {
294         return Smprintf("Error loading Gecko libraries: %s", aErr.get());
295       });
296 
297   JNI_Throw(jenv, "java/lang/Exception", msg.get());
298 }
299 
300 extern "C" APKOPEN_EXPORT void MOZ_JNICALL
Java_org_mozilla_gecko_mozglue_GeckoLoader_loadSQLiteLibsNative(JNIEnv * jenv,jclass jGeckoAppShellClass)301 Java_org_mozilla_gecko_mozglue_GeckoLoader_loadSQLiteLibsNative(
302     JNIEnv* jenv, jclass jGeckoAppShellClass) {
303   EnsureBaseProfilerInitialized();
304 
305   __android_log_print(ANDROID_LOG_ERROR, "GeckoLibLoad", "Load sqlite start\n");
306   mozglueresult rv = loadSQLiteLibs();
307   if (rv != SUCCESS) {
308     JNI_Throw(jenv, "java/lang/Exception", "Error loading sqlite libraries");
309   }
310   __android_log_print(ANDROID_LOG_ERROR, "GeckoLibLoad", "Load sqlite done\n");
311 }
312 
313 extern "C" APKOPEN_EXPORT void MOZ_JNICALL
Java_org_mozilla_gecko_mozglue_GeckoLoader_loadNSSLibsNative(JNIEnv * jenv,jclass jGeckoAppShellClass)314 Java_org_mozilla_gecko_mozglue_GeckoLoader_loadNSSLibsNative(
315     JNIEnv* jenv, jclass jGeckoAppShellClass) {
316   EnsureBaseProfilerInitialized();
317 
318   __android_log_print(ANDROID_LOG_ERROR, "GeckoLibLoad", "Load nss start\n");
319   mozglueresult rv = loadNSSLibs();
320   if (rv != SUCCESS) {
321     JNI_Throw(jenv, "java/lang/Exception", "Error loading nss libraries");
322   }
323   __android_log_print(ANDROID_LOG_ERROR, "GeckoLibLoad", "Load nss done\n");
324 }
325 
CreateArgvFromObjectArray(JNIEnv * jenv,jobjectArray jargs,int * length)326 static char** CreateArgvFromObjectArray(JNIEnv* jenv, jobjectArray jargs,
327                                         int* length) {
328   size_t stringCount = jenv->GetArrayLength(jargs);
329 
330   if (length) {
331     *length = stringCount;
332   }
333 
334   if (!stringCount) {
335     return nullptr;
336   }
337 
338   char** argv = new char*[stringCount + 1];
339 
340   argv[stringCount] = nullptr;
341 
342   for (size_t ix = 0; ix < stringCount; ix++) {
343     jstring string = (jstring)(jenv->GetObjectArrayElement(jargs, ix));
344     const char* rawString = jenv->GetStringUTFChars(string, nullptr);
345     const int strLength = jenv->GetStringUTFLength(string);
346     argv[ix] = strndup(rawString, strLength);
347     jenv->ReleaseStringUTFChars(string, rawString);
348     jenv->DeleteLocalRef(string);
349   }
350 
351   return argv;
352 }
353 
FreeArgv(char ** argv,int argc)354 static void FreeArgv(char** argv, int argc) {
355   for (int ix = 0; ix < argc; ix++) {
356     // String was allocated with strndup, so need to use free to deallocate.
357     free(argv[ix]);
358   }
359   delete[](argv);
360 }
361 
362 extern "C" APKOPEN_EXPORT void MOZ_JNICALL
Java_org_mozilla_gecko_mozglue_GeckoLoader_nativeRun(JNIEnv * jenv,jclass jc,jobjectArray jargs,int prefsFd,int prefMapFd,int ipcFd,int crashFd,int crashAnnotationFd,bool xpcshell,jstring outFilePath)363 Java_org_mozilla_gecko_mozglue_GeckoLoader_nativeRun(
364     JNIEnv* jenv, jclass jc, jobjectArray jargs, int prefsFd, int prefMapFd,
365     int ipcFd, int crashFd, int crashAnnotationFd, bool xpcshell,
366     jstring outFilePath) {
367   EnsureBaseProfilerInitialized();
368 
369   int argc = 0;
370   char** argv = CreateArgvFromObjectArray(jenv, jargs, &argc);
371 
372   if (ipcFd < 0) {
373     if (gBootstrap == nullptr) {
374       FreeArgv(argv, argc);
375       return;
376     }
377 
378 #ifdef MOZ_LINKER
379     ElfLoader::Singleton.ExpectShutdown(false);
380 #endif
381     const char* outFilePathRaw = nullptr;
382     if (xpcshell) {
383       MOZ_ASSERT(outFilePath);
384       outFilePathRaw = jenv->GetStringUTFChars(outFilePath, nullptr);
385     }
386     gBootstrap->GeckoStart(jenv, argv, argc, sAppData, xpcshell,
387                            outFilePathRaw);
388     if (outFilePathRaw) {
389       jenv->ReleaseStringUTFChars(outFilePath, outFilePathRaw);
390     }
391 #ifdef MOZ_LINKER
392     ElfLoader::Singleton.ExpectShutdown(true);
393 #endif
394   } else {
395     gBootstrap->XRE_SetAndroidChildFds(
396         jenv, {prefsFd, prefMapFd, ipcFd, crashFd, crashAnnotationFd});
397     gBootstrap->XRE_SetProcessType(argv[argc - 1]);
398 
399     XREChildData childData;
400     gBootstrap->XRE_InitChildProcess(argc - 1, argv, &childData);
401   }
402 
403 #ifdef MOZ_WIDGET_ANDROID
404 #  ifdef MOZ_PROFILE_GENERATE
405   gBootstrap->XRE_WriteLLVMProfData();
406 #  endif
407 #endif
408   gBootstrap.reset();
409   FreeArgv(argv, argc);
410 }
411 
ChildProcessInit(int argc,char * argv[])412 extern "C" APKOPEN_EXPORT mozglueresult ChildProcessInit(int argc,
413                                                          char* argv[]) {
414   EnsureBaseProfilerInitialized();
415 
416   if (loadNSSLibs() != SUCCESS) {
417     return FAILURE;
418   }
419   if (loadSQLiteLibs() != SUCCESS) {
420     return FAILURE;
421   }
422   if (loadGeckoLibs().isErr()) {
423     return FAILURE;
424   }
425 
426   gBootstrap->XRE_SetProcessType(argv[--argc]);
427 
428   XREChildData childData;
429   return NS_FAILED(gBootstrap->XRE_InitChildProcess(argc, argv, &childData));
430 }
431 
432 // Does current process name end with ':media'?
IsMediaProcess()433 static bool IsMediaProcess() {
434   pid_t pid = getpid();
435   char str[256];
436   SprintfLiteral(str, "/proc/%d/cmdline", pid);
437   FILE* f = fopen(str, "r");
438   if (f) {
439     fgets(str, sizeof(str), f);
440     fclose(f);
441     const size_t strLen = strlen(str);
442     const char suffix[] = ":media";
443     const size_t suffixLen = sizeof(suffix) - 1;
444     if (strLen >= suffixLen &&
445         !strncmp(str + strLen - suffixLen, suffix, suffixLen)) {
446       return true;
447     }
448   }
449   return false;
450 }
451 
452 #ifndef SYS_rt_tgsigqueueinfo
453 #  define SYS_rt_tgsigqueueinfo __NR_rt_tgsigqueueinfo
454 #endif
455 /* Copy of http://androidxref.com/7.1.1_r6/xref/bionic/linker/debugger.cpp#262,
456  * with debuggerd related code stripped.
457  *
458  * Copyright (C) 2008 The Android Open Source Project
459  * All rights reserved.
460  *
461  * Redistribution and use in source and binary forms, with or without
462  * modification, are permitted provided that the following conditions
463  * are met:
464  *  * Redistributions of source code must retain the above copyright
465  *    notice, this list of conditions and the following disclaimer.
466  *  * Redistributions in binary form must reproduce the above copyright
467  *    notice, this list of conditions and the following disclaimer in
468  *    the documentation and/or other materials provided with the
469  *    distribution.
470  *
471  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
472  * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
473  * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
474  * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
475  * COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
476  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
477  * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
478  * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
479  * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
480  * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
481  * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
482  * SUCH DAMAGE.
483  */
CatchFatalSignals(int num,siginfo_t * info,void * context)484 static void CatchFatalSignals(int num, siginfo_t* info, void* context) {
485   // It's possible somebody cleared the SA_SIGINFO flag, which would mean
486   // our "info" arg holds an undefined value.
487   struct sigaction action = {};
488   if ((sigaction(num, nullptr, &action) < 0) ||
489       !(action.sa_flags & SA_SIGINFO)) {
490     info = nullptr;
491   }
492 
493   // We need to return from the signal handler so that debuggerd can dump the
494   // thread that crashed, but returning here does not guarantee that the signal
495   // will be thrown again, even for SIGSEGV and friends, since the signal could
496   // have been sent manually. Resend the signal with rt_tgsigqueueinfo(2) to
497   // preserve the SA_SIGINFO contents.
498   signal(num, SIG_DFL);
499 
500   struct siginfo si;
501   if (!info) {
502     memset(&si, 0, sizeof(si));
503     si.si_code = SI_USER;
504     si.si_pid = getpid();
505     si.si_uid = getuid();
506     info = &si;
507   } else if (info->si_code >= 0 || info->si_code == SI_TKILL) {
508     // rt_tgsigqueueinfo(2)'s documentation appears to be incorrect on kernels
509     // that contain commit 66dd34a (3.9+). The manpage claims to only allow
510     // negative si_code values that are not SI_TKILL, but 66dd34a changed the
511     // check to allow all si_code values in calls coming from inside the house.
512   }
513 
514   int rc = syscall(SYS_rt_tgsigqueueinfo, getpid(), gettid(), num, info);
515   if (rc != 0) {
516     __android_log_print(ANDROID_LOG_FATAL, "mozglue",
517                         "failed to resend signal during crash: %s",
518                         strerror(errno));
519     _exit(0);
520   }
521 }
522 
523 extern "C" APKOPEN_EXPORT void MOZ_JNICALL
Java_org_mozilla_gecko_mozglue_GeckoLoader_suppressCrashDialog(JNIEnv * jenv,jclass jc)524 Java_org_mozilla_gecko_mozglue_GeckoLoader_suppressCrashDialog(JNIEnv* jenv,
525                                                                jclass jc) {
526   MOZ_RELEASE_ASSERT(IsMediaProcess(),
527                      "Suppress crash dialog only for media process");
528   // Restoring to SIG_DFL will crash on x86/Android M devices (see bug 1374556)
529   // so copy Android code
530   // (http://androidxref.com/7.1.1_r6/xref/bionic/linker/debugger.cpp#302). See
531   // comments above CatchFatalSignals() for copyright notice.
532   struct sigaction action;
533   memset(&action, 0, sizeof(action));
534   sigemptyset(&action.sa_mask);
535   action.sa_sigaction = &CatchFatalSignals;
536   action.sa_flags = SA_RESTART | SA_SIGINFO;
537 
538   // Use the alternate signal stack if available so we can catch stack
539   // overflows.
540   action.sa_flags |= SA_ONSTACK;
541 
542   sigaction(SIGABRT, &action, nullptr);
543   sigaction(SIGBUS, &action, nullptr);
544   sigaction(SIGFPE, &action, nullptr);
545   sigaction(SIGILL, &action, nullptr);
546   sigaction(SIGSEGV, &action, nullptr);
547 #if defined(SIGSTKFLT)
548   sigaction(SIGSTKFLT, &action, nullptr);
549 #endif
550   sigaction(SIGTRAP, &action, nullptr);
551 }
552