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         __pthread_init(&libpthread_funcs, envp, apple, vars);
 148         _libc_initializer(&libc_funcs, envp, apple, vars);
 149
 150         // TODO: Move __malloc_init before __libc_init after breaking malloc's upward link to Libc
 151         __malloc_init(apple);
 152
 153 #if !TARGET_OS_SIMULATOR
 154         /* <rdar://problem/9664631> */
 155         __keymgr_initializer();
 156 #endif
 157
 158         _dyld_initializer();
 159
 160
 161         libdispatch_init();
 162         _libxpc_initializer();
 163
 164 #if !(TARGET_OS_EMBEDDED || TARGET_OS_SIMULATOR)
 165         _libsecinit_initializer();
 166 #endif
 167
 168         __stack_logging_early_finished();
 169
 170 #if TARGET_OS_EMBEDDED && !TARGET_OS_WATCH && !__LP64__
 171         _vminterpose_init();
 172 #endif
 173
 174         _libtrace_init(); // must be initialized after dispatch
 175
 176 #if !TARGET_OS_IPHONE
 177     /* <rdar://problem/22139800> - Preserve the old behavior of apple[] for
 178      * programs that haven't linked against newer SDK.
 179          */
 180 #define APPLE0_PREFIX "executable_path="
 181         if (dyld_get_program_sdk_version() < DYLD_MACOSX_VERSION_10_11){
 182                 if (strncmp(apple[0], APPLE0_PREFIX, strlen(APPLE0_PREFIX)) == 0){
 183                         apple[0] = apple[0] + strlen(APPLE0_PREFIX);
 184                 }
 185         }
 186 #endif
 187
 188         /* <rdar://problem/11588042>
 189          * C99 standard has the following in section 7.5(3):
 190          * "The value of errno is zero at program startup, but is never set
 191          * to zero by any library function."
 192          */
 193         errno = 0;
 194 }
 195
 196 /*
 197  * libSystem_atfork_{prepare,parent,child}() are called by libc during fork(2).
 198  * They call the corresponding atfork handlers for other libsystem components.
 199  */
 200 void
 201 libSystem_atfork_prepare(void)
 202 {
 203         _libSC_info_fork_prepare();
 204         xpc_atfork_prepare();
 205         dispatch_atfork_prepare();
 206         _pthread_fork_prepare();
 207         _malloc_fork_prepare();
 208 }
 209
 210 void
 211 libSystem_atfork_parent(void)
 212 {
 213         _malloc_fork_parent();
 214         _pthread_fork_parent();
 215         dispatch_atfork_parent();
 216         xpc_atfork_parent();
 217         _libSC_info_fork_parent();
 218 }
 219
 220 void
 221 libSystem_atfork_child(void)
 222 {
 223         _dyld_fork_child();
 224         _pthread_fork_child();
 225         _malloc_fork_child();
 226         dispatch_atfork_child();
 227
 228         _mach_fork_child();
 229         _libc_fork_child();
 230
 231 #if defined(HAVE_SYSTEM_CORESERVICES)
 232         _libcoreservices_fork_child();
 233 #endif
 234
 235         _asl_fork_child();
 236         _notify_fork_child();
 237         xpc_atfork_child();
 238         _libSC_info_fork_child();
 239
 240         _pthread_fork_child_postinit();
 241         _libtrace_fork_child(); // no prep work required for the fork
 242 }
 243
 244 /*
 245  *  Old crt1.o glue used to call through mach_init_routine which was used to initialize libSystem.
 246  *  LibSystem now auto-initializes but mach_init_routine is left for binary compatibility.
 247  */
 248 static void mach_init_old(void) {}
 249 void (*mach_init_routine)(void) = &mach_init_old;
 250
 251 /*
 252  *      This __crashreporter_info__ symbol is for all non-dylib parts of libSystem.
 253  */
 254 const char *__crashreporter_info__;
 255 asm (".desc __crashreporter_info__, 0x10");