The Tor Browser: mozglue/build/BionicGlue.cpp@97036ab72558 (annotated)

mozglue/build/BionicGlue.cpp@97036ab72558 (annotated)

mozglue/build/BionicGlue.cpp

Tue, 06 Jan 2015 21:39:09 +0100

author: Michael Schloh von Bennewitz <michael@schloh.com>
date: Tue, 06 Jan 2015 21:39:09 +0100
branch: TOR_BUG_9701
changeset 8: 97036ab72558
permissions: -rw-r--r--

Conditionally force memory storage according to privacy.thirdparty.isolate;
This solves Tor bug #9701, complying with disk avoidance documented in
https://www.torproject.org/projects/torbrowser/design/#disk-avoidance.

 /* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
 /* This Source Code Form is subject to the terms of the Mozilla Public
  * License, v. 2.0. If a copy of the MPL was not distributed with this file,
  * You can obtain one at http://mozilla.org/MPL/2.0/. */
 #include <pthread.h>
 #include <string.h>
 #include <stdlib.h>
 #include <time.h>
 #include <unistd.h>
 #include <android/log.h>
 #include <sys/syscall.h>
 #include "mozilla/Alignment.h"
 #include <vector>
 #define NS_EXPORT __attribute__ ((visibility("default")))
 #if ANDROID_VERSION < 17 || defined(MOZ_WIDGET_ANDROID)
 /* Android doesn't have pthread_atfork(), so we need to use our own. */
 struct AtForkFuncs {
   void (*prepare)(void);
   void (*parent)(void);
   void (*child)(void);
 };
 /* jemalloc's initialization calls pthread_atfork. When pthread_atfork (see
  * further below) stores the corresponding data, it's going to allocate memory,
  * which will loop back to jemalloc's initialization, leading to a dead-lock.
  * So, for that specific vector, we use a special allocator that returns a
  * static buffer for small sizes, and force the initial vector capacity to
  * a size enough to store one atfork function table. */
 template <typename T>
 struct SpecialAllocator: public std::allocator<T>
 {
   SpecialAllocator(): bufUsed(false) {}
   inline typename std::allocator<T>::pointer allocate(typename std::allocator<T>::size_type n, const void * = 0) {
     if (!bufUsed && n == 1) {
       bufUsed = true;
       return buf.addr();
     }
     return reinterpret_cast<T *>(::operator new(sizeof(T) * n));
   }
   inline void deallocate(typename std::allocator<T>::pointer p, typename std::allocator<T>::size_type n) {
     if (p == buf.addr())
       bufUsed = false;
     else
       ::operator delete(p);
   }
   template<typename U>
   struct rebind {
     typedef SpecialAllocator<U> other;
   };
 private:
   mozilla::AlignedStorage2<T> buf;
   bool bufUsed;
 };
 static std::vector<AtForkFuncs, SpecialAllocator<AtForkFuncs> > atfork;
 #endif
 #ifdef MOZ_WIDGET_GONK
 #include "cpuacct.h"
 #define WRAP(x) x
 #if ANDROID_VERSION < 17 || defined(MOZ_WIDGET_ANDROID)
 extern "C" NS_EXPORT int
 timer_create(clockid_t, struct sigevent*, timer_t*)
 {
   __android_log_print(ANDROID_LOG_ERROR, "BionicGlue", "timer_create not supported!");
   abort();
   return -1;
 }
 #endif
 #else
 #define cpuacct_add(x)
 #define WRAP(x) __wrap_##x
 #endif
 #if ANDROID_VERSION < 17 || defined(MOZ_WIDGET_ANDROID)
 extern "C" NS_EXPORT int
 WRAP(pthread_atfork)(void (*prepare)(void), void (*parent)(void), void (*child)(void))
 {
   AtForkFuncs funcs;
   funcs.prepare = prepare;
   funcs.parent = parent;
   funcs.child = child;
   if (!atfork.capacity())
     atfork.reserve(1);
   atfork.push_back(funcs);
   return 0;
 }
 extern "C" NS_EXPORT pid_t
 WRAP(fork)(void)
 {
   pid_t pid;
   for (auto it = atfork.rbegin();
        it < atfork.rend(); ++it)
     if (it->prepare)
       it->prepare();
   switch ((pid = syscall(__NR_clone, SIGCHLD, NULL, NULL, NULL, NULL))) {
   case 0:
     cpuacct_add(getuid());
     for (auto it = atfork.begin();
          it < atfork.end(); ++it)
       if (it->child)
         it->child();
     break;
   default:
     for (auto it = atfork.begin();
          it < atfork.end(); ++it)
       if (it->parent)
         it->parent();
   }
   return pid;
 }
 #endif
 extern "C" NS_EXPORT int
 WRAP(raise)(int sig)
 {
   // Bug 741272: Bionic incorrectly uses kill(), which signals the
   // process, and thus could signal another thread (and let this one
   // return "successfully" from raising a fatal signal).
   //
   // Bug 943170: POSIX specifies pthread_kill(pthread_self(), sig) as
   // equivalent to raise(sig), but Bionic also has a bug with these
   // functions, where a forked child will kill its parent instead.
   extern pid_t gettid(void);
   return syscall(__NR_tgkill, getpid(), gettid(), sig);
 }
 /*
  * The following wrappers for PR_Xxx are needed until we can get
  * PR_DuplicateEnvironment landed in NSPR.
  * See see bug 772734 and bug 773414.
  *
  * We can't #include the pr headers here, and we can't call any of the
  * PR/PL functions either, so we just reimplemnt using native code.
  */
 static pthread_mutex_t  _pr_envLock = PTHREAD_MUTEX_INITIALIZER;
 extern "C" NS_EXPORT char*
 __wrap_PR_GetEnv(const char *var)
 {
     char *ev;
     pthread_mutex_lock(&_pr_envLock);
     ev = getenv(var);
     pthread_mutex_unlock(&_pr_envLock);
     return ev;
 }
 extern "C" NS_EXPORT int
 __wrap_PR_SetEnv(const char *string)
 {
     int result;
     if ( !strchr(string, '=')) return(-1);
     pthread_mutex_lock(&_pr_envLock);
     result = putenv(string);
     pthread_mutex_unlock(&_pr_envLock);
     return (result)? -1 : 0;
 }
 extern "C" NS_EXPORT pthread_mutex_t *
 PR_GetEnvLock(void)
 {
   return &_pr_envLock;
 }
 /* Amazon Kindle Fire HD's libc provides most of the
  * functions in string.h as weak symbols, which dlsym
  * cannot resolve. Thus, we must wrap these functions.
  * See bug 791419.
  */
 #ifndef MOZ_WIDGET_GONK
 #include <string.h>
 extern "C" NS_EXPORT void* __real_memccpy(void * a0, const void * a1, int a2, size_t a3);
 extern "C" NS_EXPORT void* __real_memchr(const void * a0, int a1, size_t a2);
 extern "C" NS_EXPORT void* __real_memrchr(const void * a0, int a1, size_t a2);
 extern "C" NS_EXPORT int __real_memcmp(const void * a0, const void * a1, size_t a2);
 extern "C" NS_EXPORT void* __real_memcpy(void * a0, const void * a1, size_t a2);
 extern "C" NS_EXPORT void* __real_memmove(void * a0, const void * a1, size_t a2);
 extern "C" NS_EXPORT void* __real_memset(void * a0, int a1, size_t a2);
 extern "C" NS_EXPORT void* __real_memmem(const void * a0, size_t a1, const void * a2, size_t a3);
 extern "C" NS_EXPORT void __real_memswap(void * a0, void * a1, size_t a2);
 extern "C" NS_EXPORT char* __real_index(const char * a0, int a1);
 extern "C" NS_EXPORT char* __real_strchr(const char * a0, int a1);
 extern "C" NS_EXPORT char* __real_strrchr(const char * a0, int a1);
 extern "C" NS_EXPORT size_t __real_strlen(const char * a0);
 extern "C" NS_EXPORT int __real_strcmp(const char * a0, const char * a1);
 extern "C" NS_EXPORT char* __real_strcpy(char * a0, const char * a1);
 extern "C" NS_EXPORT char* __real_strcat(char * a0, const char * a1);
 extern "C" NS_EXPORT int __real_strcasecmp(const char * a0, const char * a1);
 extern "C" NS_EXPORT int __real_strncasecmp(const char * a0, const char * a1, size_t a2);
 extern "C" NS_EXPORT char* __real_strstr(const char * a0, const char * a1);
 extern "C" NS_EXPORT char* __real_strcasestr(const char * a0, const char * a1);
 extern "C" NS_EXPORT char* __real_strtok(char * a0, const char * a1);
 extern "C" NS_EXPORT char* __real_strtok_r(char * a0, const char * a1, char** a2);
 extern "C" NS_EXPORT char* __real_strerror(int a0);
 extern "C" NS_EXPORT int __real_strerror_r(int a0, char * a1, size_t a2);
 extern "C" NS_EXPORT size_t __real_strnlen(const char * a0, size_t a1);
 extern "C" NS_EXPORT char* __real_strncat(char * a0, const char * a1, size_t a2);
 extern "C" NS_EXPORT int __real_strncmp(const char * a0, const char * a1, size_t a2);
 extern "C" NS_EXPORT char* __real_strncpy(char * a0, const char * a1, size_t a2);
 extern "C" NS_EXPORT size_t __real_strlcat(char * a0, const char * a1, size_t a2);
 extern "C" NS_EXPORT size_t __real_strlcpy(char * a0, const char * a1, size_t a2);
 extern "C" NS_EXPORT size_t __real_strcspn(const char * a0, const char * a1);
 extern "C" NS_EXPORT char* __real_strpbrk(const char * a0, const char * a1);
 extern "C" NS_EXPORT char* __real_strsep(char ** a0, const char * a1);
 extern "C" NS_EXPORT size_t __real_strspn(const char * a0, const char * a1);
 extern "C" NS_EXPORT int __real_strcoll(const char * a0, const char * a1);
 extern "C" NS_EXPORT size_t __real_strxfrm(char * a0, const char * a1, size_t a2);
 extern "C" NS_EXPORT void* __wrap_memccpy(void * a0, const void * a1, int a2, size_t a3) { return __real_memccpy(a0, a1, a2, a3); }
 extern "C" NS_EXPORT void* __wrap_memchr(const void * a0, int a1, size_t a2) { return __real_memchr(a0, a1, a2); }
 extern "C" NS_EXPORT void* __wrap_memrchr(const void * a0, int a1, size_t a2) { return __real_memrchr(a0, a1, a2); }
 extern "C" NS_EXPORT int __wrap_memcmp(const void * a0, const void * a1, size_t a2) { return __real_memcmp(a0, a1, a2); }
 extern "C" NS_EXPORT void* __wrap_memcpy(void * a0, const void * a1, size_t a2) { return __real_memcpy(a0, a1, a2); }
 extern "C" NS_EXPORT void* __wrap_memmove(void * a0, const void * a1, size_t a2) { return __real_memmove(a0, a1, a2); }
 extern "C" NS_EXPORT void* __wrap_memset(void * a0, int a1, size_t a2) { return __real_memset(a0, a1, a2); }
 extern "C" NS_EXPORT void* __wrap_memmem(const void * a0, size_t a1, const void * a2, size_t a3) { return __real_memmem(a0, a1, a2, a3); }
 extern "C" NS_EXPORT void __wrap_memswap(void * a0, void * a1, size_t a2) { __real_memswap(a0, a1, a2); }
 extern "C" NS_EXPORT char* __wrap_index(const char * a0, int a1) { return __real_index(a0, a1); }
 extern "C" NS_EXPORT char* __wrap_strchr(const char * a0, int a1) { return __real_strchr(a0, a1); }
 extern "C" NS_EXPORT char* __wrap_strrchr(const char * a0, int a1) { return __real_strrchr(a0, a1); }
 extern "C" NS_EXPORT size_t __wrap_strlen(const char * a0) { return __real_strlen(a0); }
 extern "C" NS_EXPORT int __wrap_strcmp(const char * a0, const char * a1) { return __real_strcmp(a0, a1); }
 extern "C" NS_EXPORT char* __wrap_strcpy(char * a0, const char * a1) { return __real_strcpy(a0, a1); }
 extern "C" NS_EXPORT char* __wrap_strcat(char * a0, const char * a1) { return __real_strcat(a0, a1); }
 extern "C" NS_EXPORT int __wrap_strcasecmp(const char * a0, const char * a1) { return __real_strcasecmp(a0, a1); }
 extern "C" NS_EXPORT int __wrap_strncasecmp(const char * a0, const char * a1, size_t a2) { return __real_strncasecmp(a0, a1, a2); }
 extern "C" NS_EXPORT char* __wrap_strstr(const char * a0, const char * a1) { return __real_strstr(a0, a1); }
 extern "C" NS_EXPORT char* __wrap_strcasestr(const char * a0, const char * a1) { return __real_strcasestr(a0, a1); }
 extern "C" NS_EXPORT char* __wrap_strtok(char * a0, const char * a1) { return __real_strtok(a0, a1); }
 extern "C" NS_EXPORT char* __wrap_strtok_r(char * a0, const char * a1, char** a2) { return __real_strtok_r(a0, a1, a2); }
 extern "C" NS_EXPORT char* __wrap_strerror(int a0) { return __real_strerror(a0); }
 extern "C" NS_EXPORT int __wrap_strerror_r(int a0, char * a1, size_t a2) { return __real_strerror_r(a0, a1, a2); }
 extern "C" NS_EXPORT size_t __wrap_strnlen(const char * a0, size_t a1) { return __real_strnlen(a0, a1); }
 extern "C" NS_EXPORT char* __wrap_strncat(char * a0, const char * a1, size_t a2) { return __real_strncat(a0, a1, a2); }
 extern "C" NS_EXPORT int __wrap_strncmp(const char * a0, const char * a1, size_t a2) { return __real_strncmp(a0, a1, a2); }
 extern "C" NS_EXPORT char* __wrap_strncpy(char * a0, const char * a1, size_t a2) { return __real_strncpy(a0, a1, a2); }
 extern "C" NS_EXPORT size_t __wrap_strlcat(char * a0, const char * a1, size_t a2) { return __real_strlcat(a0, a1, a2); }
 extern "C" NS_EXPORT size_t __wrap_strlcpy(char * a0, const char * a1, size_t a2) { return __real_strlcpy(a0, a1, a2); }
 extern "C" NS_EXPORT size_t __wrap_strcspn(const char * a0, const char * a1) { return __real_strcspn(a0, a1); }
 extern "C" NS_EXPORT char* __wrap_strpbrk(const char * a0, const char * a1) { return __real_strpbrk(a0, a1); }
 extern "C" NS_EXPORT char* __wrap_strsep(char ** a0, const char * a1) { return __real_strsep(a0, a1); }
 extern "C" NS_EXPORT size_t __wrap_strspn(const char * a0, const char * a1) { return __real_strspn(a0, a1); }
 extern "C" NS_EXPORT int __wrap_strcoll(const char * a0, const char * a1) { return __real_strcoll(a0, a1); }
 extern "C" NS_EXPORT size_t __wrap_strxfrm(char * a0, const char * a1, size_t a2) { return __real_strxfrm(a0, a1, a2); }
 #endif

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mozglue/build/BionicGlue.cpp@97036ab72558 (annotated)

mozglue/build/BionicGlue.cpp