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 <errno.h>
  38 #include <_libkernel_init.h> // Must be after voucher_private.h
  39
  40 #include <mach-o/dyld_priv.h>
  41
  42 // system library initialisers
  43 extern void mach_init(void);                    // from libsystem_kernel.dylib
  44 extern void __libplatform_init(void *future_use, const char *envp[], const char *apple[], const struct ProgramVars *vars);
  45 extern void __pthread_init(const struct _libpthread_functions *libpthread_funcs, const char *envp[], const char *apple[], const struct ProgramVars *vars);      // from libsystem_pthread.dylib
  46 extern void __malloc_init(const char *apple[]); // from libsystem_malloc.dylib
  47 extern void __keymgr_initializer(void);         // from libkeymgr.dylib
  48 extern void _dyld_initializer(void);            // from libdyld.dylib
  49 extern void libdispatch_init(void);             // from libdispatch.dylib
  50 extern void _libxpc_initializer(void);          // from libxpc.dylib
  51 extern void _libsecinit_initializer(void);        // from libsecinit.dylib
  52 extern void _libtrace_init(void);               // from libsystem_trace.dylib
  53 extern void _container_init(const char *apple[]); // from libsystem_containermanager.dylib
  54 extern void __libdarwin_init(void);             // from libsystem_darwin.dylib
  55
  56
  57 // signal malloc stack logging that initialisation has finished
  58 extern void __stack_logging_early_finished(void); // form libsystem_c.dylib
  59
  60 // clear qos tsd (from pthread)
  61 extern void _pthread_clear_qos_tsd(mach_port_t) __attribute__((weak_import));
  62
  63 // system library atfork handlers
  64 extern void _pthread_atfork_prepare(void);
  65 extern void _pthread_atfork_parent(void);
  66 extern void _pthread_atfork_child(void);
  67 extern void _pthread_atfork_prepare_handlers();
  68 extern void _pthread_atfork_parent_handlers(void);
  69 extern void _pthread_atfork_child_handlers(void);
  70 extern void _pthread_exit_if_canceled(int);
  71
  72 extern void dispatch_atfork_prepare(void);
  73 extern void dispatch_atfork_parent(void);
  74 extern void dispatch_atfork_child(void);
  75
  76 extern void _libtrace_fork_child(void);
  77
  78 extern void _malloc_fork_prepare(void);
  79 extern void _malloc_fork_parent(void);
  80 extern void _malloc_fork_child(void);
  81
  82 extern void _mach_fork_child(void);
  83 extern void _notify_fork_child(void);
  84 extern void _dyld_fork_child(void);
  85 extern void xpc_atfork_prepare(void);
  86 extern void xpc_atfork_parent(void);
  87 extern void xpc_atfork_child(void);
  88 extern void _libSC_info_fork_prepare(void);
  89 extern void _libSC_info_fork_parent(void);
  90 extern void _libSC_info_fork_child(void);
  91 extern void _asl_fork_child(void);
  92
  93 #if defined(HAVE_SYSTEM_CORESERVICES)
  94 // libsystem_coreservices.dylib
  95 extern void _libcoreservices_fork_child(void);
  96 extern char *_dirhelper(int, char *, size_t);
  97 #endif
  98
  99 #if TARGET_OS_EMBEDDED && !TARGET_OS_WATCH && !__LP64__
 100 extern void _vminterpose_init(void);
 101 #endif
 102
 103 // advance decls for below;
 104 void libSystem_atfork_prepare(void);
 105 void libSystem_atfork_parent(void);
 106 void libSystem_atfork_child(void);
 107
 108 // libsyscall_initializer() initializes all of libSystem.dylib
 109 // <rdar://problem/4892197>
 110 __attribute__((constructor))
 111 static void
 112 libSystem_initializer(int argc,
 113                       const char* argv[],
 114                       const char* envp[],
 115                       const char* apple[],
 116                       const struct ProgramVars* vars)
 117 {
 118         static const struct _libkernel_functions libkernel_funcs = {
 119                 .version = 3,
 120                 // V1 functions
 121                 .dlsym = dlsym,
 122                 .malloc = malloc,
 123                 .free = free,
 124                 .realloc = realloc,
 125                 ._pthread_exit_if_canceled = _pthread_exit_if_canceled,
 126                 // V2 functions (removed)
 127                 // V3 functions
 128                 .pthread_clear_qos_tsd = _pthread_clear_qos_tsd,
 129         };
 130
 131         static const struct _libpthread_functions libpthread_funcs = {
 132                 .version = 2,
 133                 .exit = exit,
 134                 .malloc = malloc,
 135                 .free = free,
 136         };
 137
 138         static const struct _libc_functions libc_funcs = {
 139                 .version = 1,
 140                 .atfork_prepare = libSystem_atfork_prepare,
 141                 .atfork_parent = libSystem_atfork_parent,
 142                 .atfork_child = libSystem_atfork_child,
 143 #if defined(HAVE_SYSTEM_CORESERVICES)
 144                 .dirhelper = _dirhelper,
 145 #endif
 146         };
 147
 148         __libkernel_init(&libkernel_funcs, envp, apple, vars);
 149
 150         __libplatform_init(NULL, envp, apple, vars);
 151
 152         __pthread_init(&libpthread_funcs, envp, apple, vars);
 153
 154         _libc_initializer(&libc_funcs, envp, apple, vars);
 155
 156         // TODO: Move __malloc_init before __libc_init after breaking malloc's upward link to Libc
 157         __malloc_init(apple);
 158
 159 #if TARGET_OS_OSX
 160         /* <rdar://problem/9664631> */
 161         __keymgr_initializer();
 162 #endif
 163
 164         _dyld_initializer();
 165
 166         libdispatch_init();
 167         _libxpc_initializer();
 168
 169         // must be initialized after dispatch
 170         _libtrace_init();
 171
 172 #if !(TARGET_OS_EMBEDDED || TARGET_OS_SIMULATOR)
 173         _libsecinit_initializer();
 174 #endif
 175
 176 #if TARGET_OS_EMBEDDED
 177         _container_init(apple);
 178 #endif
 179
 180         __libdarwin_init();
 181
 182         __stack_logging_early_finished();
 183
 184 #if TARGET_OS_EMBEDDED && TARGET_OS_IOS && !__LP64__
 185         _vminterpose_init();
 186 #endif
 187
 188 #if !TARGET_OS_IPHONE
 189     /* <rdar://problem/22139800> - Preserve the old behavior of apple[] for
 190      * programs that haven't linked against newer SDK.
 191          */
 192 #define APPLE0_PREFIX "executable_path="
 193         if (dyld_get_program_sdk_version() < DYLD_MACOSX_VERSION_10_11){
 194                 if (strncmp(apple[0], APPLE0_PREFIX, strlen(APPLE0_PREFIX)) == 0){
 195                         apple[0] = apple[0] + strlen(APPLE0_PREFIX);
 196                 }
 197         }
 198 #endif
 199
 200         /* <rdar://problem/11588042>
 201          * C99 standard has the following in section 7.5(3):
 202          * "The value of errno is zero at program startup, but is never set
 203          * to zero by any library function."
 204          */
 205         errno = 0;
 206 }
 207
 208 /*
 209  * libSystem_atfork_{prepare,parent,child}() are called by libc during fork(2).
 210  */
 211 void
 212 libSystem_atfork_prepare(void)
 213 {
 214         // first call client prepare handlers registered with pthread_atfork()
 215         _pthread_atfork_prepare_handlers();
 216
 217         // second call hardwired fork prepare handlers for Libsystem components
 218         // in the _reverse_ order of library initalization above
 219         _libSC_info_fork_prepare();
 220         xpc_atfork_prepare();
 221         dispatch_atfork_prepare();
 222         _malloc_fork_prepare();
 223         _pthread_atfork_prepare();
 224 }
 225
 226 void
 227 libSystem_atfork_parent(void)
 228 {
 229         // first call hardwired fork parent handlers for Libsystem components
 230         // in the order of library initalization above
 231         _pthread_atfork_parent();
 232         _malloc_fork_parent();
 233         dispatch_atfork_parent();
 234         xpc_atfork_parent();
 235         _libSC_info_fork_parent();
 236
 237         // second call client parent handlers registered with pthread_atfork()
 238         _pthread_atfork_parent_handlers();
 239 }
 240
 241 void
 242 libSystem_atfork_child(void)
 243 {
 244         // first call hardwired fork child handlers for Libsystem components
 245         // in the order of library initalization above
 246         _dyld_fork_child();
 247         _pthread_atfork_child();
 248         _mach_fork_child();
 249         _malloc_fork_child();
 250         _libc_fork_child(); // _arc4_fork_child calls malloc
 251         dispatch_atfork_child();
 252 #if defined(HAVE_SYSTEM_CORESERVICES)
 253         _libcoreservices_fork_child();
 254 #endif
 255         _asl_fork_child();
 256         _notify_fork_child();
 257         xpc_atfork_child();
 258         _libtrace_fork_child();
 259         _libSC_info_fork_child();
 260
 261         // second call client parent handlers registered with pthread_atfork()
 262         _pthread_atfork_child_handlers();
 263 }
 264
 265 /*
 266  *  Old crt1.o glue used to call through mach_init_routine which was used to initialize libSystem.
 267  *  LibSystem now auto-initializes but mach_init_routine is left for binary compatibility.
 268  */
 269 static void mach_init_old(void) {}
 270 void (*mach_init_routine)(void) = &mach_init_old;
 271
 272 /*
 273  *      This __crashreporter_info__ symbol is for all non-dylib parts of libSystem.
 274  */
 275 const char *__crashreporter_info__;
 276 asm (".desc __crashreporter_info__, 0x10");