init.c

   1 /*
   2  * Copyright (c) 2007, 2008, 2011-2013 Apple Inc. All rights reserved.
   3  *
   4  * @APPLE_OSREFERENCE_LICENSE_HEADER_START@
   5  *
   6  * This file contains Original Code and/or Modifications of Original Code
   7  * as defined in and that are subject to the Apple Public Source License
   8  * Version 2.0 (the 'License'). You may not use this file except in
   9  * compliance with the License. The rights granted to you under the License
  10  * may not be used to create, or enable the creation or redistribution of,
  11  * unlawful or unlicensed copies of an Apple operating system, or to
  12  * circumvent, violate, or enable the circumvention or violation of, any
  13  * terms of an Apple operating system software license agreement.
  14  *
  15  * Please obtain a copy of the License at
  16  * http://www.opensource.apple.com/apsl/ and read it before using this file.
  17  *
  18  * The Original Code and all software distributed under the License are
  19  * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
  20  * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
  21  * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
  22  * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
  23  * Please see the License for the specific language governing rights and
  24  * limitations under the License.
  25  *
  26  * @APPLE_OSREFERENCE_LICENSE_HEADER_END@
  27  */
  28
  29 #include <TargetConditionals.h> // for TARGET_OS_*
  30
  31 #include <stddef.h>
  32 #include <stdlib.h>
  33 #include <libc_private.h>
  34 #include <pthread.h>
  35 #include <pthread/private.h>
  36 #include <dlfcn.h>
  37 #include <fcntl.h>
  38 #include <errno.h>
  39 #include <_libkernel_init.h> // Must be after voucher_private.h
  40
  41 #include <mach-o/dyld_priv.h>
  42
  43 // system library initialisers
  44 extern void mach_init(void);                    // from libsystem_kernel.dylib
  45 extern void __libplatform_init(void *future_use, const char *envp[], const char *apple[], const struct ProgramVars *vars);
  46 extern void __pthread_init(const struct _libpthread_functions *libpthread_funcs, const char *envp[], const char *apple[], const struct ProgramVars *vars);      // from libsystem_pthread.dylib
  47 extern void __malloc_init(const char *apple[]); // from libsystem_malloc.dylib
  48 extern void __keymgr_initializer(void);         // from libkeymgr.dylib
  49 extern void _dyld_initializer(void);            // from libdyld.dylib
  50 extern void libdispatch_init(void);             // from libdispatch.dylib
  51 extern void _libxpc_initializer(void);          // from libxpc.dylib
  52 extern void _libsecinit_initializer(void);        // from libsecinit.dylib
  53 extern void _libtrace_init(void);               // from libsystem_trace.dylib
  54 extern void _container_init(const char *apple[]); // from libsystem_containermanager.dylib
  55 extern void __libdarwin_init(void);             // from libsystem_darwin.dylib
  56
  57
  58 // signal malloc stack logging that initialisation has finished
  59 extern void __stack_logging_early_finished(void); // form libsystem_c.dylib
  60
  61 // clear qos tsd (from pthread)
  62 extern void _pthread_clear_qos_tsd(mach_port_t) __attribute__((weak_import));
  63
  64 // system library atfork handlers
  65 extern void _pthread_atfork_prepare(void);
  66 extern void _pthread_atfork_parent(void);
  67 extern void _pthread_atfork_child(void);
  68 extern void _pthread_atfork_prepare_handlers();
  69 extern void _pthread_atfork_parent_handlers(void);
  70 extern void _pthread_atfork_child_handlers(void);
  71 extern void _pthread_exit_if_canceled(int);
  72
  73 extern void dispatch_atfork_prepare(void);
  74 extern void dispatch_atfork_parent(void);
  75 extern void dispatch_atfork_child(void);
  76
  77 extern void _libtrace_fork_child(void);
  78
  79 extern void _malloc_fork_prepare(void);
  80 extern void _malloc_fork_parent(void);
  81 extern void _malloc_fork_child(void);
  82
  83 extern void _mach_fork_child(void);
  84 extern void _notify_fork_child(void);
  85 extern void _dyld_fork_child(void);
  86 extern void xpc_atfork_prepare(void);
  87 extern void xpc_atfork_parent(void);
  88 extern void xpc_atfork_child(void);
  89 extern void _libSC_info_fork_prepare(void);
  90 extern void _libSC_info_fork_parent(void);
  91 extern void _libSC_info_fork_child(void);
  92 extern void _asl_fork_child(void);
  93
  94 #if defined(HAVE_SYSTEM_CORESERVICES)
  95 // libsystem_coreservices.dylib
  96 extern void _libcoreservices_fork_child(void);
  97 extern char *_dirhelper(int, char *, size_t);
  98 #endif
  99
 100 #if TARGET_OS_EMBEDDED && !TARGET_OS_WATCH && !__LP64__
 101 extern void _vminterpose_init(void);
 102 #endif
 103
 104 // advance decls for below;
 105 void libSystem_atfork_prepare(void);
 106 void libSystem_atfork_parent(void);
 107 void libSystem_atfork_child(void);
 108
 109 #if CURRENT_VARIANT_asan
 110 const char *__asan_default_options(void);
 111 #endif
 112
 113 // libsyscall_initializer() initializes all of libSystem.dylib
 114 // <rdar://problem/4892197>
 115 __attribute__((constructor))
 116 static void
 117 libSystem_initializer(int argc,
 118                       const char* argv[],
 119                       const char* envp[],
 120                       const char* apple[],
 121                       const struct ProgramVars* vars)
 122 {
 123         static const struct _libkernel_functions libkernel_funcs = {
 124                 .version = 3,
 125                 // V1 functions
 126                 .dlsym = dlsym,
 127                 .malloc = malloc,
 128                 .free = free,
 129                 .realloc = realloc,
 130                 ._pthread_exit_if_canceled = _pthread_exit_if_canceled,
 131                 // V2 functions (removed)
 132                 // V3 functions
 133                 .pthread_clear_qos_tsd = _pthread_clear_qos_tsd,
 134         };
 135
 136         static const struct _libpthread_functions libpthread_funcs = {
 137                 .version = 2,
 138                 .exit = exit,
 139                 .malloc = malloc,
 140                 .free = free,
 141         };
 142
 143         static const struct _libc_functions libc_funcs = {
 144                 .version = 1,
 145                 .atfork_prepare = libSystem_atfork_prepare,
 146                 .atfork_parent = libSystem_atfork_parent,
 147                 .atfork_child = libSystem_atfork_child,
 148 #if defined(HAVE_SYSTEM_CORESERVICES)
 149                 .dirhelper = _dirhelper,
 150 #endif
 151         };
 152
 153         __libkernel_init(&libkernel_funcs, envp, apple, vars);
 154
 155         __libplatform_init(NULL, envp, apple, vars);
 156
 157         __pthread_init(&libpthread_funcs, envp, apple, vars);
 158
 159         _libc_initializer(&libc_funcs, envp, apple, vars);
 160
 161         // TODO: Move __malloc_init before __libc_init after breaking malloc's upward link to Libc
 162         __malloc_init(apple);
 163
 164 #if TARGET_OS_OSX
 165         /* <rdar://problem/9664631> */
 166         __keymgr_initializer();
 167 #endif
 168
 169         // No ASan interceptors are invoked before this point. ASan is normally initialized via the malloc interceptor:
 170         // _dyld_initializer() -> tlv_load_notification -> wrap_malloc -> ASanInitInternal
 171
 172         _dyld_initializer();
 173
 174         libdispatch_init();
 175         _libxpc_initializer();
 176
 177 #if CURRENT_VARIANT_asan
 178         setenv("DT_BYPASS_LEAKS_CHECK", "1", 1);
 179 #endif
 180
 181         // must be initialized after dispatch
 182         _libtrace_init();
 183
 184 #if !(TARGET_OS_EMBEDDED || TARGET_OS_SIMULATOR)
 185         _libsecinit_initializer();
 186 #endif
 187
 188 #if TARGET_OS_EMBEDDED
 189         _container_init(apple);
 190 #endif
 191
 192         __libdarwin_init();
 193
 194         __stack_logging_early_finished();
 195
 196 #if TARGET_OS_EMBEDDED && TARGET_OS_IOS && !__LP64__
 197         _vminterpose_init();
 198 #endif
 199
 200 #if !TARGET_OS_IPHONE
 201     /* <rdar://problem/22139800> - Preserve the old behavior of apple[] for
 202      * programs that haven't linked against newer SDK.
 203          */
 204 #define APPLE0_PREFIX "executable_path="
 205         if (dyld_get_program_sdk_version() < DYLD_MACOSX_VERSION_10_11){
 206                 if (strncmp(apple[0], APPLE0_PREFIX, strlen(APPLE0_PREFIX)) == 0){
 207                         apple[0] = apple[0] + strlen(APPLE0_PREFIX);
 208                 }
 209         }
 210 #endif
 211
 212         /* <rdar://problem/11588042>
 213          * C99 standard has the following in section 7.5(3):
 214          * "The value of errno is zero at program startup, but is never set
 215          * to zero by any library function."
 216          */
 217         errno = 0;
 218 }
 219
 220 /*
 221  * libSystem_atfork_{prepare,parent,child}() are called by libc during fork(2).
 222  */
 223 void
 224 libSystem_atfork_prepare(void)
 225 {
 226         // first call client prepare handlers registered with pthread_atfork()
 227         _pthread_atfork_prepare_handlers();
 228
 229         // second call hardwired fork prepare handlers for Libsystem components
 230         // in the _reverse_ order of library initalization above
 231         _libSC_info_fork_prepare();
 232         xpc_atfork_prepare();
 233         dispatch_atfork_prepare();
 234         _malloc_fork_prepare();
 235         _pthread_atfork_prepare();
 236 }
 237
 238 void
 239 libSystem_atfork_parent(void)
 240 {
 241         // first call hardwired fork parent handlers for Libsystem components
 242         // in the order of library initalization above
 243         _pthread_atfork_parent();
 244         _malloc_fork_parent();
 245         dispatch_atfork_parent();
 246         xpc_atfork_parent();
 247         _libSC_info_fork_parent();
 248
 249         // second call client parent handlers registered with pthread_atfork()
 250         _pthread_atfork_parent_handlers();
 251 }
 252
 253 void
 254 libSystem_atfork_child(void)
 255 {
 256         // first call hardwired fork child handlers for Libsystem components
 257         // in the order of library initalization above
 258         _dyld_fork_child();
 259         _pthread_atfork_child();
 260         _mach_fork_child();
 261         _malloc_fork_child();
 262         _libc_fork_child(); // _arc4_fork_child calls malloc
 263         dispatch_atfork_child();
 264 #if defined(HAVE_SYSTEM_CORESERVICES)
 265         _libcoreservices_fork_child();
 266 #endif
 267         _asl_fork_child();
 268         _notify_fork_child();
 269         xpc_atfork_child();
 270         _libtrace_fork_child();
 271         _libSC_info_fork_child();
 272
 273         // second call client parent handlers registered with pthread_atfork()
 274         _pthread_atfork_child_handlers();
 275 }
 276
 277 #if CURRENT_VARIANT_asan
 278 char dynamic_asan_opts[1024] = {0};
 279 const char *__asan_default_options(void) {
 280         int fd = open("/System/Library/Preferences/com.apple.asan.options", O_RDONLY);
 281         if (fd != -1) {
 282                 ssize_t remaining_size = sizeof(dynamic_asan_opts) - 1;
 283                 char *p = dynamic_asan_opts;
 284                 ssize_t read_bytes = 0;
 285                 do {
 286                         read_bytes = read(fd, p, remaining_size);
 287                         remaining_size -= read_bytes;
 288                 } while (read_bytes > 0);
 289                 close(fd);
 290
 291                 if (dynamic_asan_opts[0]) {
 292                         return dynamic_asan_opts;
 293                 }
 294         }
 295
 296         return "color=never:handle_segv=0:handle_sigbus=0:handle_sigill=0:handle_sigfpe=0";
 297 }
 298 #endif
 299
 300 /*
 301  *  Old crt1.o glue used to call through mach_init_routine which was used to initialize libSystem.
 302  *  LibSystem now auto-initializes but mach_init_routine is left for binary compatibility.
 303  */
 304 static void mach_init_old(void) {}
 305 void (*mach_init_routine)(void) = &mach_init_old;
 306
 307 /*
 308  *      This __crashreporter_info__ symbol is for all non-dylib parts of libSystem.
 309  */
 310 const char *__crashreporter_info__;
 311 asm (".desc __crashreporter_info__, 0x10");