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