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 <unistd.h>
  34 #include <corecrypto/cc_priv.h>
  35 #include <libc_private.h>
  36 #include <pthread.h>
  37 #include <pthread/private.h>
  38 #if !TARGET_OS_DRIVERKIT
  39 #include <dlfcn.h>
  40 #endif
  41 #include <fcntl.h>
  42 #include <errno.h>
  43 #include <sys/kdebug.h>
  44 #include <_libkernel_init.h> // Must be after voucher_private.h
  45 #include <malloc_implementation.h>
  46
  47 #include <mach-o/dyld_priv.h>
  48
  49 // system library initialisers
  50 extern void mach_init(void);                    // from libsystem_kernel.dylib
  51 extern void __libplatform_init(void *future_use, const char *envp[], const char *apple[], const struct ProgramVars *vars);
  52 extern void __pthread_init(const struct _libpthread_functions *libpthread_funcs, const char *envp[], const char *apple[], const struct ProgramVars *vars);      // from libsystem_pthread.dylib
  53 extern void __malloc_init(const char *apple[]); // from libsystem_malloc.dylib
  54 extern void __keymgr_initializer(void);         // from libkeymgr.dylib
  55 extern void _dyld_initializer(void);            // from libdyld.dylib
  56 extern void libdispatch_init(void);             // from libdispatch.dylib
  57 extern void _libxpc_initializer(void);          // from libxpc.dylib
  58 extern void _libsecinit_initializer(void);        // from libsecinit.dylib
  59 extern void _libtrace_init(void);               // from libsystem_trace.dylib
  60 extern void _container_init(const char *apple[]); // from libsystem_containermanager.dylib
  61 extern void __libdarwin_init(void);             // from libsystem_darwin.dylib
  62
  63
  64 // clear qos tsd (from pthread)
  65 extern void _pthread_clear_qos_tsd(mach_port_t) __attribute__((weak_import));
  66
  67 // system library atfork handlers
  68 extern void _pthread_atfork_prepare(void);
  69 extern void _pthread_atfork_parent(void);
  70 extern void _pthread_atfork_child(void);
  71 extern void _pthread_atfork_prepare_handlers();
  72 extern void _pthread_atfork_parent_handlers(void);
  73 extern void _pthread_atfork_child_handlers(void);
  74 extern void _pthread_exit_if_canceled(int);
  75
  76 extern void dispatch_atfork_prepare(void);
  77 extern void dispatch_atfork_parent(void);
  78 extern void dispatch_atfork_child(void);
  79
  80 extern void _libtrace_fork_child(void);
  81
  82 extern void _malloc_fork_prepare(void);
  83 extern void _malloc_fork_parent(void);
  84 extern void _malloc_fork_child(void);
  85
  86 extern void _mach_fork_child(void);
  87 extern void _notify_fork_child(void);
  88 extern void _dyld_atfork_prepare(void);
  89 extern void _dyld_atfork_parent(void);
  90 extern void _dyld_fork_child(void);
  91 extern void xpc_atfork_prepare(void);
  92 extern void xpc_atfork_parent(void);
  93 extern void xpc_atfork_child(void);
  94 extern void _libSC_info_fork_prepare(void);
  95 extern void _libSC_info_fork_parent(void);
  96 extern void _libSC_info_fork_child(void);
  97 extern void _asl_fork_child(void);
  98
  99 #if defined(HAVE_SYSTEM_CORESERVICES)
 100 // libsystem_coreservices.dylib
 101 extern void _libcoreservices_fork_child(void);
 102 extern char *_dirhelper(int, char *, size_t);
 103 #endif
 104
 105 // advance decls for below;
 106 void libSystem_atfork_prepare(void);
 107 void libSystem_atfork_parent(void);
 108 void libSystem_atfork_child(void);
 109
 110 #if CURRENT_VARIANT_asan
 111 const char *__asan_default_options(void);
 112 #endif
 113
 114 static inline void
 115 _libSystem_ktrace4(uint32_t code, uint64_t a, uint64_t b, uint64_t c, uint64_t d)
 116 {
 117         if (__builtin_expect(*(volatile uint32_t *)_COMM_PAGE_KDEBUG_ENABLE == 0, 1)) return;
 118         kdebug_trace(code, a, b, c, d);
 119 }
 120 #define _libSystem_ktrace3(code, a, b, c) _libSystem_ktrace4(code, a, b, c, 0)
 121 #define _libSystem_ktrace2(code, a, b)    _libSystem_ktrace4(code, a, b, 0, 0)
 122 #define _libSystem_ktrace1(code, a)       _libSystem_ktrace4(code, a, 0, 0, 0)
 123 #define _libSystem_ktrace0(code)          _libSystem_ktrace4(code, 0, 0, 0, 0)
 124
 125 /*
 126  * these define stable Ariadne tracepoints. If initializers are removed, or
 127  * added, then old tracepoints MUST NOT be recycled.
 128  */
 129 enum {
 130         ARIADNE_LIFECYCLE_libsystem_init = ARIADNEDBG_CODE(220, 4),
 131 };
 132
 133 /*
 134  * These represent the initializer "name"
 135  *
 136  * They happen to match the order of the initializers at some point in time,
 137  * but there's no guarantee made that traecepoints will appear in numerical
 138  * order. As initializers come and go, new codes shall be allocated,
 139  * and no slots reused.
 140  */
 141 enum init_func {
 142         INIT_SYSTEM = 0,
 143         INIT_KERNEL = 1,
 144         INIT_PLATFORM = 2,
 145         INIT_PTHREAD = 3,
 146         INIT_LIBC = 4,
 147         INIT_MALLOC = 5,
 148         INIT_KEYMGR = 6,
 149         INIT_DYLD = 7,
 150         INIT_LIBDISPATCH = 8,
 151         INIT_LIBXPC = 9,
 152         INIT_LIBTRACE = 10,
 153         INIT_SECINIT = 11,
 154         INIT_CONTAINERMGR = 12,
 155         INIT_DARWIN = 13,
 156 };
 157
 158 #define _libSystem_ktrace_init_func(what) \
 159         _libSystem_ktrace1(ARIADNE_LIFECYCLE_libsystem_init | DBG_FUNC_NONE, INIT_##what)
 160
 161 // libsyscall_initializer() initializes all of libSystem.dylib
 162 // <rdar://problem/4892197>
 163 __attribute__((constructor))
 164 static void
 165 libSystem_initializer(int argc,
 166                       const char* argv[],
 167                       const char* envp[],
 168                       const char* apple[],
 169                       const struct ProgramVars* vars)
 170 {
 171         static const struct _libkernel_functions libkernel_funcs = {
 172                 .version = 4,
 173                 // V1 functions
 174 #if !TARGET_OS_DRIVERKIT
 175                 .dlsym = dlsym,
 176 #endif
 177                 .malloc = malloc,
 178                 .free = free,
 179                 .realloc = realloc,
 180                 ._pthread_exit_if_canceled = _pthread_exit_if_canceled,
 181                 // V2 functions (removed)
 182                 // V3 functions
 183                 .pthread_clear_qos_tsd = _pthread_clear_qos_tsd,
 184                 // V4 functions
 185                 .pthread_current_stack_contains_np = pthread_current_stack_contains_np,
 186         };
 187
 188         static const struct _libpthread_functions libpthread_funcs = {
 189                 .version = 2,
 190                 .exit = exit,
 191                 .malloc = malloc,
 192                 .free = free,
 193         };
 194
 195         static const struct _libc_functions libc_funcs = {
 196                 .version = 1,
 197                 .atfork_prepare = libSystem_atfork_prepare,
 198                 .atfork_parent = libSystem_atfork_parent,
 199                 .atfork_child = libSystem_atfork_child,
 200 #if defined(HAVE_SYSTEM_CORESERVICES)
 201                 .dirhelper = _dirhelper,
 202 #endif
 203         };
 204
 205         static const struct _malloc_functions malloc_funcs = {
 206                 .version = 1,
 207 #if !TARGET_OS_DRIVERKIT
 208                 .dlopen = dlopen,
 209                 .dlsym = dlsym,
 210 #endif
 211         };
 212
 213         _libSystem_ktrace0(ARIADNE_LIFECYCLE_libsystem_init | DBG_FUNC_START);
 214
 215         __libkernel_init(&libkernel_funcs, envp, apple, vars);
 216         _libSystem_ktrace_init_func(KERNEL);
 217
 218         __libplatform_init(NULL, envp, apple, vars);
 219         _libSystem_ktrace_init_func(PLATFORM);
 220
 221         __pthread_init(&libpthread_funcs, envp, apple, vars);
 222         _libSystem_ktrace_init_func(PTHREAD);
 223
 224         _libc_initializer(&libc_funcs, envp, apple, vars);
 225         _libSystem_ktrace_init_func(LIBC);
 226
 227         // TODO: Move __malloc_init before __libc_init after breaking malloc's upward link to Libc
 228         // Note that __malloc_init() will also initialize ASAN when it is present
 229         __malloc_init(apple);
 230         _libSystem_ktrace_init_func(MALLOC);
 231
 232 #if TARGET_OS_OSX
 233         /* <rdar://problem/9664631> */
 234         __keymgr_initializer();
 235         _libSystem_ktrace_init_func(KEYMGR);
 236 #endif
 237
 238         _dyld_initializer();
 239         _libSystem_ktrace_init_func(DYLD);
 240
 241         libdispatch_init();
 242         _libSystem_ktrace_init_func(LIBDISPATCH);
 243
 244 #if !TARGET_OS_DRIVERKIT
 245         _libxpc_initializer();
 246         _libSystem_ktrace_init_func(LIBXPC);
 247
 248 #if CURRENT_VARIANT_asan
 249         setenv("DT_BYPASS_LEAKS_CHECK", "1", 1);
 250 #endif
 251 #endif // !TARGET_OS_DRIVERKIT
 252
 253         // must be initialized after dispatch
 254         _libtrace_init();
 255         _libSystem_ktrace_init_func(LIBTRACE);
 256
 257 #if !TARGET_OS_DRIVERKIT
 258 #if defined(HAVE_SYSTEM_SECINIT)
 259         _libsecinit_initializer();
 260         _libSystem_ktrace_init_func(SECINIT);
 261 #endif
 262
 263 #if defined(HAVE_SYSTEM_CONTAINERMANAGER)
 264         _container_init(apple);
 265         _libSystem_ktrace_init_func(CONTAINERMGR);
 266 #endif
 267
 268         __libdarwin_init();
 269         _libSystem_ktrace_init_func(DARWIN);
 270 #endif // !TARGET_OS_DRIVERKIT
 271
 272         __stack_logging_early_finished(&malloc_funcs);
 273
 274 #if !TARGET_OS_IPHONE
 275         /* <rdar://problem/22139800> - Preserve the old behavior of apple[] for
 276          * programs that haven't linked against newer SDK.
 277          */
 278 #define APPLE0_PREFIX "executable_path="
 279         if (dyld_get_program_sdk_version() < DYLD_MACOSX_VERSION_10_11){
 280                 if (strncmp(apple[0], APPLE0_PREFIX, strlen(APPLE0_PREFIX)) == 0){
 281                         apple[0] = apple[0] + strlen(APPLE0_PREFIX);
 282                 }
 283         }
 284 #endif
 285
 286 #if TARGET_OS_OSX && !defined(__i386__)
 287         bool enable_system_version_compat = false;
 288         bool enable_ios_version_compat = false;
 289         char *system_version_compat_override = getenv("SYSTEM_VERSION_COMPAT");
 290         if (system_version_compat_override != NULL) {
 291                 long override = strtol(system_version_compat_override, NULL, 0);
 292                 if (override == 1) {
 293                         enable_system_version_compat = true;
 294                 } else if (override == 2) {
 295                         enable_ios_version_compat = true;
 296                 }
 297         } else if (dyld_get_active_platform() == PLATFORM_MACCATALYST) {
 298                 if (!dyld_program_sdk_at_least(dyld_platform_version_iOS_14_0)) {
 299                         enable_system_version_compat = true;
 300                 }
 301         } else if (dyld_get_active_platform() == PLATFORM_IOS) {
 302                 enable_ios_version_compat = true;
 303         } else if (!dyld_program_sdk_at_least(dyld_platform_version_macOS_10_16)) {
 304                 enable_system_version_compat = true;
 305         }
 306
 307         if (enable_system_version_compat || enable_ios_version_compat) {
 308                 struct _libkernel_late_init_config config = {
 309                         .version = 2,
 310                         .enable_system_version_compat = enable_system_version_compat,
 311                         .enable_ios_version_compat = enable_ios_version_compat,
 312                 };
 313                 __libkernel_init_late(&config);
 314         }
 315 #endif // TARGET_OS_OSX && !defined(__i386__)
 316
 317         _libSystem_ktrace0(ARIADNE_LIFECYCLE_libsystem_init | DBG_FUNC_END);
 318
 319         /* <rdar://problem/11588042>
 320          * C99 standard has the following in section 7.5(3):
 321          * "The value of errno is zero at program startup, but is never set
 322          * to zero by any library function."
 323          */
 324         errno = 0;
 325 }
 326
 327 /*
 328  * libSystem_atfork_{prepare,parent,child}() are called by libc during fork(2).
 329  */
 330 void
 331 libSystem_atfork_prepare(void)
 332 {
 333         // first call client prepare handlers registered with pthread_atfork()
 334         _pthread_atfork_prepare_handlers();
 335
 336         // second call hardwired fork prepare handlers for Libsystem components
 337         // in the _reverse_ order of library initalization above
 338 #if !TARGET_OS_DRIVERKIT
 339         _libSC_info_fork_prepare();
 340         xpc_atfork_prepare();
 341 #endif // !TARGET_OS_DRIVERKIT
 342         dispatch_atfork_prepare();
 343         _dyld_atfork_prepare();
 344         cc_atfork_prepare();
 345         _malloc_fork_prepare();
 346         _pthread_atfork_prepare();
 347 }
 348
 349 void
 350 libSystem_atfork_parent(void)
 351 {
 352         // first call hardwired fork parent handlers for Libsystem components
 353         // in the order of library initalization above
 354         _pthread_atfork_parent();
 355         _malloc_fork_parent();
 356         cc_atfork_parent();
 357         _dyld_atfork_parent();
 358         dispatch_atfork_parent();
 359 #if !TARGET_OS_DRIVERKIT
 360         xpc_atfork_parent();
 361         _libSC_info_fork_parent();
 362 #endif // !TARGET_OS_DRIVERKIT
 363
 364         // second call client parent handlers registered with pthread_atfork()
 365         _pthread_atfork_parent_handlers();
 366 }
 367
 368 void
 369 libSystem_atfork_child(void)
 370 {
 371         // first call hardwired fork child handlers for Libsystem components
 372         // in the order of library initalization above
 373         _mach_fork_child();
 374         _pthread_atfork_child();
 375         _malloc_fork_child();
 376         cc_atfork_child();
 377         _libc_fork_child(); // _arc4_fork_child calls malloc
 378         _dyld_fork_child();
 379         dispatch_atfork_child();
 380 #if !TARGET_OS_DRIVERKIT
 381 #if defined(HAVE_SYSTEM_CORESERVICES)
 382         _libcoreservices_fork_child();
 383 #endif
 384         _asl_fork_child();
 385         _notify_fork_child();
 386         xpc_atfork_child();
 387 #endif // !TARGET_OS_DRIVERKIT
 388         _libtrace_fork_child();
 389 #if !TARGET_OS_DRIVERKIT
 390         _libSC_info_fork_child();
 391 #endif // !TARGET_OS_DRIVERKIT
 392
 393         // second call client parent handlers registered with pthread_atfork()
 394         _pthread_atfork_child_handlers();
 395 }
 396
 397 #if CURRENT_VARIANT_asan
 398 #define DEFAULT_ASAN_OPTIONS "color=never" \
 399         ":handle_segv=0:handle_sigbus=0:handle_sigill=0:handle_sigfpe=0" \
 400         ":external_symbolizer_path=" \
 401         ":log_path=stderr:log_exe_name=0" \
 402         ":halt_on_error=0" \
 403         ":print_module_map=2" \
 404         ":start_deactivated=1" \
 405         ":detect_odr_violation=0"
 406 char dynamic_asan_opts[1024] = {0};
 407 const char *__asan_default_options(void) {
 408         char executable_path[4096] = {0};
 409         uint32_t size = sizeof(executable_path);
 410         const char *process_name = "";
 411         if (_NSGetExecutablePath(executable_path, &size) == 0) {
 412                 process_name = strrchr(executable_path, '/') + 1;
 413         }
 414
 415         int fd = open("/System/Library/Preferences/com.apple.asan.options", O_RDONLY);
 416         if (fd != -1) {
 417                 ssize_t remaining_size = sizeof(dynamic_asan_opts) - 1;
 418                 char *p = dynamic_asan_opts;
 419                 ssize_t read_bytes = 0;
 420                 do {
 421                         read_bytes = read(fd, p, remaining_size);
 422                         remaining_size -= read_bytes;
 423                 } while (read_bytes > 0);
 424                 close(fd);
 425
 426                 if (dynamic_asan_opts[0]) {
 427                         return dynamic_asan_opts;
 428                 }
 429         }
 430
 431         return DEFAULT_ASAN_OPTIONS;
 432 }
 433 #endif
 434
 435 /*
 436  *  Old crt1.o glue used to call through mach_init_routine which was used to initialize libSystem.
 437  *  LibSystem now auto-initializes but mach_init_routine is left for binary compatibility.
 438  */
 439 static void mach_init_old(void) {}
 440 void (*mach_init_routine)(void) = &mach_init_old;
 441
 442 /*
 443  *      This __crashreporter_info__ symbol is for all non-dylib parts of libSystem.
 444  */
 445 const char *__crashreporter_info__;
 446 asm (".desc __crashreporter_info__, 0x10");