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_EMBEDDED
  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 // system library initialisers
  41 extern void mach_init(void);                    // from libsystem_kernel.dylib
  42 extern void __libplatform_init(void *future_use, const char *envp[], const char *apple[], const struct ProgramVars *vars);
  43 extern void __pthread_init(const struct _libpthread_functions *libpthread_funcs, const char *envp[], const char *apple[], const struct ProgramVars *vars);      // from libsystem_pthread.dylib
  44 extern void __malloc_init(const char *apple[]); // from libsystem_malloc.dylib
  45 extern void __keymgr_initializer(void);         // from libkeymgr.dylib
  46 extern void _dyld_initializer(void);            // from libdyld.dylib
  47 extern void libdispatch_init(void);             // from libdispatch.dylib
  48 extern void _libxpc_initializer(void);          // from libxpc.dylib
  49 extern void _libsecinit_initializer(void);        // from libsecinit.dylib
  50
  51
  52 // signal malloc stack logging that initialisation has finished
  53 extern void __stack_logging_early_finished(void); // form libsystem_c.dylib
  54
  55 // clear qos tsd (from pthread)
  56 extern void _pthread_clear_qos_tsd(mach_port_t) __attribute__((weak_import));
  57
  58 // system library atfork handlers
  59 extern void _pthread_fork_prepare(void);
  60 extern void _pthread_fork_parent(void);
  61 extern void _pthread_fork_child(void);
  62 extern void _pthread_fork_child_postinit(void);
  63 extern void _pthread_exit_if_canceled(int);
  64
  65 extern void dispatch_atfork_prepare(void);
  66 extern void dispatch_atfork_parent(void);
  67 extern void dispatch_atfork_child(void);
  68
  69 extern void _malloc_fork_prepare(void);
  70 extern void _malloc_fork_parent(void);
  71 extern void _malloc_fork_child(void);
  72
  73 extern void _mach_fork_child(void);
  74 extern void _notify_fork_child(void);
  75 extern void _dyld_fork_child(void);
  76 extern void xpc_atfork_prepare(void);
  77 extern void xpc_atfork_parent(void);
  78 extern void xpc_atfork_child(void);
  79 extern void _libSC_info_fork_prepare(void);
  80 extern void _libSC_info_fork_parent(void);
  81 extern void _libSC_info_fork_child(void);
  82 extern void _asl_fork_child(void);
  83
  84 #if defined(HAVE_SYSTEM_CORESERVICES)
  85 // libsystem_coreservices.dylib
  86 extern void _libcoreservices_fork_child(void);
  87 extern char *_dirhelper(int, char *, size_t);
  88 #endif
  89
  90 #if TARGET_IPHONE_SIMULATOR
  91 // no-op _pthread_clear_qos_tsd in the simulator, as its an upcall from libsyscall
  92 #define _pthread_clear_qos_tsd NULL
  93 #endif
  94
  95 // advance decls for below;
  96 void libSystem_atfork_prepare(void);
  97 void libSystem_atfork_parent(void);
  98 void libSystem_atfork_child(void);
  99
 100 // libsyscall_initializer() initializes all of libSystem.dylib
 101 // <rdar://problem/4892197>
 102 __attribute__((constructor))
 103 static void
 104 libSystem_initializer(int argc,
 105                       const char* argv[],
 106                       const char* envp[],
 107                       const char* apple[],
 108                       const struct ProgramVars* vars)
 109 {
 110         static const struct _libkernel_functions libkernel_funcs = {
 111                 .version = 3,
 112                 // V1 functions
 113                 .dlsym = dlsym,
 114                 .malloc = malloc,
 115                 .free = free,
 116                 .realloc = realloc,
 117                 ._pthread_exit_if_canceled = _pthread_exit_if_canceled,
 118                 // V2 functions (removed)
 119                 // V3 functions
 120                 .pthread_clear_qos_tsd = _pthread_clear_qos_tsd,
 121         };
 122
 123         static const struct _libpthread_functions libpthread_funcs = {
 124                 .version = 2,
 125                 .exit = exit,
 126                 .malloc = malloc,
 127                 .free = free,
 128         };
 129
 130         static const struct _libc_functions libc_funcs = {
 131                 .version = 1,
 132                 .atfork_prepare = libSystem_atfork_prepare,
 133                 .atfork_parent = libSystem_atfork_parent,
 134                 .atfork_child = libSystem_atfork_child,
 135 #if defined(HAVE_SYSTEM_CORESERVICES)
 136                 .dirhelper = _dirhelper,
 137 #endif
 138         };
 139
 140         __libkernel_init(&libkernel_funcs, envp, apple, vars);
 141
 142         __libplatform_init(NULL, envp, apple, vars);
 143         __pthread_init(&libpthread_funcs, envp, apple, vars);
 144         _libc_initializer(&libc_funcs, envp, apple, vars);
 145
 146         // TODO: Move __malloc_init before __libc_init after breaking malloc's upward link to Libc
 147         __malloc_init(apple);
 148
 149 #if !TARGET_IPHONE_SIMULATOR
 150         /* <rdar://problem/9664631> */
 151         __keymgr_initializer();
 152 #endif
 153
 154         _dyld_initializer();
 155         libdispatch_init();
 156         _libxpc_initializer();
 157
 158 #if !(TARGET_OS_EMBEDDED || TARGET_OS_IPHONE || TARGET_IPHONE_SIMULATOR)
 159         _libsecinit_initializer();
 160 #endif
 161
 162         __stack_logging_early_finished();
 163
 164
 165         /* <rdar://problem/11588042>
 166          * C99 standard has the following in section 7.5(3):
 167          * "The value of errno is zero at program startup, but is never set
 168          * to zero by any library function."
 169          */
 170         errno = 0;
 171 }
 172
 173 /*
 174  * libSystem_atfork_{prepare,parent,child}() are called by libc during fork(2).
 175  * They call the corresponding atfork handlers for other libsystem components.
 176  */
 177 void
 178 libSystem_atfork_prepare(void)
 179 {
 180         _libSC_info_fork_prepare();
 181         xpc_atfork_prepare();
 182         dispatch_atfork_prepare();
 183         _pthread_fork_prepare();
 184         _malloc_fork_prepare();
 185 }
 186
 187 void
 188 libSystem_atfork_parent(void)
 189 {
 190         _malloc_fork_parent();
 191         _pthread_fork_parent();
 192         dispatch_atfork_parent();
 193         xpc_atfork_parent();
 194         _libSC_info_fork_parent();
 195 }
 196
 197 void
 198 libSystem_atfork_child(void)
 199 {
 200         _dyld_fork_child();
 201         _pthread_fork_child();
 202         _malloc_fork_child();
 203         dispatch_atfork_child();
 204
 205         _mach_fork_child();
 206         _libc_fork_child();
 207
 208 #if defined(HAVE_SYSTEM_CORESERVICES)
 209         _libcoreservices_fork_child();
 210 #endif
 211
 212         _asl_fork_child();
 213         _notify_fork_child();
 214         xpc_atfork_child();
 215         _libSC_info_fork_child();
 216
 217         _pthread_fork_child_postinit();
 218 }
 219
 220 /*
 221  *  Old crt1.o glue used to call through mach_init_routine which was used to initialize libSystem.
 222  *  LibSystem now auto-initializes but mach_init_routine is left for binary compatibility.
 223  */
 224 static void mach_init_old(void) {}
 225 void (*mach_init_routine)(void) = &mach_init_old;
 226
 227 /*
 228  *      This __crashreporter_info__ symbol is for all non-dylib parts of libSystem.
 229  */
 230 const char *__crashreporter_info__;
 231 asm (".desc __crashreporter_info__, 0x10");