init.c

   1 /*
   2  * Copyright (c) 2007, 2008, 2011, 2012 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 <pthread.h>
  32 #include <pthread/private.h>
  33 #include <_libkernel_init.h>
  34 #include <stdlib.h>
  35 #include <dlfcn.h>
  36 #include <errno.h>
  37 #include <TargetConditionals.h>
  38
  39 struct ProgramVars; /* forward reference */
  40
  41 // system library initialisers
  42 extern void bootstrap_init(void);               // from liblaunch.dylib
  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 __libc_init(const struct ProgramVars *vars, void (*atfork_prepare)(void), void (*atfork_parent)(void), void (*atfork_child)(void), const char *apple[]);    // from libsystem_c.dylib
  47 extern void __malloc_init(const char *apple[]); // from libsystem_malloc.dylib
  48 extern void __keymgr_initializer(void);         // from libkeymgr.dylib
  49 extern void _dyld_initializer(void);            // from libdyld.dylib
  50 extern void libdispatch_init(void);             // from libdispatch.dylib
  51 extern void _libxpc_initializer(void);          // from libxpc.dylib
  52
  53 // signal malloc stack logging that initialisation has finished
  54 extern void __stack_logging_early_finished(void); // form libsystem_c.dylib
  55
  56 // system library atfork handlers
  57 extern void _pthread_fork_prepare(void);
  58 extern void _pthread_fork_parent(void);
  59 extern void _pthread_fork_child(void);
  60 extern void _pthread_fork_child_postinit(void);
  61
  62 extern void dispatch_atfork_prepare(void);
  63 extern void dispatch_atfork_parent(void);
  64 extern void dispatch_atfork_child(void);
  65
  66 extern void _malloc_fork_prepare(void);
  67 extern void _malloc_fork_parent(void);
  68 extern void _malloc_fork_child(void);
  69
  70 extern void _mach_fork_child(void);
  71 extern void _libc_fork_child(void);
  72 extern void _notify_fork_child(void);
  73 extern void _dyld_fork_child(void);
  74 extern void xpc_atfork_prepare(void);
  75 extern void xpc_atfork_parent(void);
  76 extern void xpc_atfork_child(void);
  77 extern void _libSC_info_fork_prepare(void);
  78 extern void _libSC_info_fork_parent(void);
  79 extern void _libSC_info_fork_child(void);
  80 extern void _asl_fork_child(void);
  81
  82 // advance decls for below;
  83 void libSystem_atfork_prepare(void);
  84 void libSystem_atfork_parent(void);
  85 void libSystem_atfork_child(void);
  86
  87 void _pthread_exit_if_canceled(int);
  88
  89 /*
  90  * libsyscall_initializer() initializes all of libSystem.dylib <rdar://problem/4892197>
  91  */
  92 static __attribute__((constructor))
  93 void libSystem_initializer(int argc, const char* argv[], const char* envp[], const char* apple[], const struct ProgramVars* vars)
  94 {
  95         static const struct _libkernel_functions libkernel_funcs = {
  96                 .version = 1,
  97                 .dlsym = dlsym,
  98                 .malloc = malloc,
  99                 .free = free,
 100                 .realloc = realloc,
 101                 ._pthread_exit_if_canceled = _pthread_exit_if_canceled,
 102         };
 103
 104         static const struct _libpthread_functions libpthread_funcs = {
 105                 .version = 1,
 106                 .exit = exit,
 107         };
 108
 109         __libkernel_init(&libkernel_funcs, envp, apple, vars);
 110
 111         bootstrap_init();
 112         __libplatform_init(NULL, envp, apple, vars);
 113
 114         __pthread_init(&libpthread_funcs, envp, apple, vars);
 115         __libc_init(vars, libSystem_atfork_prepare, libSystem_atfork_parent, libSystem_atfork_child, apple);
 116
 117         // TODO: Move __malloc_init before __libc_init after breaking malloc's upward link to Libc
 118         __malloc_init(apple);
 119
 120         _dyld_initializer();
 121         libdispatch_init();
 122         _libxpc_initializer();
 123
 124         __stack_logging_early_finished();
 125
 126         /* <rdar://problem/11588042>
 127          * C99 standard has the following in section 7.5(3):
 128          * "The value of errno is zero at program startup, but is never set
 129          * to zero by any library function."
 130          */
 131         errno = 0;
 132 }
 133
 134 /*
 135  * libSystem_atfork_{prepare,parent,child}() are called by libc when we fork, then we deal with running fork handlers
 136  * for everyone else.
 137  */
 138 void libSystem_atfork_prepare(void)
 139 {
 140         _libSC_info_fork_prepare();
 141         xpc_atfork_prepare();
 142         dispatch_atfork_prepare();
 143         _pthread_fork_prepare();
 144         _malloc_fork_prepare();
 145 }
 146
 147 void libSystem_atfork_parent(void)
 148 {
 149         _malloc_fork_parent();
 150         _pthread_fork_parent();
 151         dispatch_atfork_parent();
 152         xpc_atfork_parent();
 153         _libSC_info_fork_parent();
 154 }
 155
 156 void libSystem_atfork_child(void)
 157 {
 158         _dyld_fork_child();
 159         _pthread_fork_child();
 160         _malloc_fork_child();
 161         dispatch_atfork_child();
 162
 163         bootstrap_init();
 164         _mach_fork_child();
 165         _libc_fork_child();
 166         _asl_fork_child();
 167         _notify_fork_child();
 168         xpc_atfork_child();
 169         _libSC_info_fork_child();
 170
 171         _pthread_fork_child_postinit();
 172 }
 173
 174 /*
 175  *  Old crt1.o glue used to call through mach_init_routine which was used to initialize libSystem.
 176  *  LibSystem now auto-initializes but mach_init_routine is left for binary compatibility.
 177  */
 178 static void mach_init_old(void) {}
 179 void (*mach_init_routine)(void) = &mach_init_old;
 180
 181 /*
 182  *      This __crashreporter_info__ symbol is for all non-dylib parts of libSystem.
 183  */
 184 const char *__crashreporter_info__;
 185 asm (".desc __crashreporter_info__, 0x10");