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
  54
  55 // signal malloc stack logging that initialisation has finished
  56 extern void __stack_logging_early_finished(void); // form libsystem_c.dylib
  57
  58 // clear qos tsd (from pthread)
  59 extern void _pthread_clear_qos_tsd(mach_port_t) __attribute__((weak_import));
  60
  61 // system library atfork handlers
  62 extern void _pthread_fork_prepare(void);
  63 extern void _pthread_fork_parent(void);
  64 extern void _pthread_fork_child(void);
  65 extern void _pthread_fork_child_postinit(void);
  66 extern void _pthread_exit_if_canceled(int);
  67
  68 extern void dispatch_atfork_prepare(void);
  69 extern void dispatch_atfork_parent(void);
  70 extern void dispatch_atfork_child(void);
  71
  72 extern void _libtrace_fork_child(void);
  73
  74 extern void _malloc_fork_prepare(void);
  75 extern void _malloc_fork_parent(void);
  76 extern void _malloc_fork_child(void);
  77
  78 extern void _mach_fork_child(void);
  79 extern void _notify_fork_child(void);
  80 extern void _dyld_fork_child(void);
  81 extern void xpc_atfork_prepare(void);
  82 extern void xpc_atfork_parent(void);
  83 extern void xpc_atfork_child(void);
  84 extern void _libSC_info_fork_prepare(void);
  85 extern void _libSC_info_fork_parent(void);
  86 extern void _libSC_info_fork_child(void);
  87 extern void _asl_fork_child(void);
  88
  89 #if defined(HAVE_SYSTEM_CORESERVICES)
  90 // libsystem_coreservices.dylib
  91 extern void _libcoreservices_fork_child(void);
  92 extern char *_dirhelper(int, char *, size_t);
  93 #endif
  94
  95 #if TARGET_OS_EMBEDDED && !TARGET_OS_WATCH && !__LP64__
  96 extern void _vminterpose_init(void);
  97 #endif
  98
  99 // advance decls for below;
 100 void libSystem_atfork_prepare(void);
 101 void libSystem_atfork_parent(void);
 102 void libSystem_atfork_child(void);
 103
 104 // libsyscall_initializer() initializes all of libSystem.dylib
 105 // <rdar://problem/4892197>
 106 __attribute__((constructor))
 107 static void
 108 libSystem_initializer(int argc,
 109                       const char* argv[],
 110                       const char* envp[],
 111                       const char* apple[],
 112                       const struct ProgramVars* vars)
 113 {
 114         static const struct _libkernel_functions libkernel_funcs = {
 115                 .version = 3,
 116                 // V1 functions
 117                 .dlsym = dlsym,
 118                 .malloc = malloc,
 119                 .free = free,
 120                 .realloc = realloc,
 121                 ._pthread_exit_if_canceled = _pthread_exit_if_canceled,
 122                 // V2 functions (removed)
 123                 // V3 functions
 124                 .pthread_clear_qos_tsd = _pthread_clear_qos_tsd,
 125         };
 126
 127         static const struct _libpthread_functions libpthread_funcs = {
 128                 .version = 2,
 129                 .exit = exit,
 130                 .malloc = malloc,
 131                 .free = free,
 132         };
 133
 134         static const struct _libc_functions libc_funcs = {
 135                 .version = 1,
 136                 .atfork_prepare = libSystem_atfork_prepare,
 137                 .atfork_parent = libSystem_atfork_parent,
 138                 .atfork_child = libSystem_atfork_child,
 139 #if defined(HAVE_SYSTEM_CORESERVICES)
 140                 .dirhelper = _dirhelper,
 141 #endif
 142         };
 143
 144         __libkernel_init(&libkernel_funcs, envp, apple, vars);
 145
 146         __libplatform_init(NULL, envp, apple, vars);
 147
 148         __pthread_init(&libpthread_funcs, envp, apple, vars);
 149
 150         _libc_initializer(&libc_funcs, envp, apple, vars);
 151
 152         // TODO: Move __malloc_init before __libc_init after breaking malloc's upward link to Libc
 153         __malloc_init(apple);
 154
 155 #if !TARGET_OS_SIMULATOR && !TARGET_OS_TV && !TARGET_OS_WATCH
 156         /* <rdar://problem/9664631> */
 157         __keymgr_initializer();
 158 #endif
 159
 160         _dyld_initializer();
 161
 162         libdispatch_init();
 163         _libxpc_initializer();
 164
 165 #if !(TARGET_OS_EMBEDDED || TARGET_OS_SIMULATOR)
 166         _libsecinit_initializer();
 167 #endif
 168
 169         __stack_logging_early_finished();
 170
 171 #if TARGET_OS_EMBEDDED && !TARGET_OS_WATCH && !__LP64__
 172         _vminterpose_init();
 173 #endif
 174
 175         _libtrace_init(); // must be initialized after dispatch
 176
 177 #if !TARGET_OS_IPHONE
 178     /* <rdar://problem/22139800> - Preserve the old behavior of apple[] for
 179      * programs that haven't linked against newer SDK.
 180          */
 181 #define APPLE0_PREFIX "executable_path="
 182         if (dyld_get_program_sdk_version() < DYLD_MACOSX_VERSION_10_11){
 183                 if (strncmp(apple[0], APPLE0_PREFIX, strlen(APPLE0_PREFIX)) == 0){
 184                         apple[0] = apple[0] + strlen(APPLE0_PREFIX);
 185                 }
 186         }
 187 #endif
 188
 189         /* <rdar://problem/11588042>
 190          * C99 standard has the following in section 7.5(3):
 191          * "The value of errno is zero at program startup, but is never set
 192          * to zero by any library function."
 193          */
 194         errno = 0;
 195 }
 196
 197 /*
 198  * libSystem_atfork_{prepare,parent,child}() are called by libc during fork(2).
 199  * They call the corresponding atfork handlers for other libsystem components.
 200  */
 201 void
 202 libSystem_atfork_prepare(void)
 203 {
 204         _libSC_info_fork_prepare();
 205         xpc_atfork_prepare();
 206         dispatch_atfork_prepare();
 207         _pthread_fork_prepare();
 208         _malloc_fork_prepare();
 209 }
 210
 211 void
 212 libSystem_atfork_parent(void)
 213 {
 214         _malloc_fork_parent();
 215         _pthread_fork_parent();
 216         dispatch_atfork_parent();
 217         xpc_atfork_parent();
 218         _libSC_info_fork_parent();
 219 }
 220
 221 void
 222 libSystem_atfork_child(void)
 223 {
 224         _dyld_fork_child();
 225         _pthread_fork_child();
 226         _malloc_fork_child();
 227         dispatch_atfork_child();
 228
 229         _mach_fork_child();
 230         _libc_fork_child();
 231
 232 #if defined(HAVE_SYSTEM_CORESERVICES)
 233         _libcoreservices_fork_child();
 234 #endif
 235
 236         _asl_fork_child();
 237         _notify_fork_child();
 238         xpc_atfork_child();
 239         _libSC_info_fork_child();
 240
 241         _pthread_fork_child_postinit();
 242         _libtrace_fork_child(); // no prep work required for the fork
 243 }
 244
 245 /*
 246  *  Old crt1.o glue used to call through mach_init_routine which was used to initialize libSystem.
 247  *  LibSystem now auto-initializes but mach_init_routine is left for binary compatibility.
 248  */
 249 static void mach_init_old(void) {}
 250 void (*mach_init_routine)(void) = &mach_init_old;
 251
 252 /*
 253  *      This __crashreporter_info__ symbol is for all non-dylib parts of libSystem.
 254  */
 255 const char *__crashreporter_info__;
 256 asm (".desc __crashreporter_info__, 0x10");