loader/preloader_mac.c

   1 /*
   2  * Preloader for macOS
   3  *
   4  * Copyright (C) 1995,96,97,98,99,2000,2001,2002 Free Software Foundation, Inc.
   5  * Copyright (C) 2004 Mike McCormack for CodeWeavers
   6  * Copyright (C) 2004 Alexandre Julliard
   7  * Copyright (C) 2017 Michael Müller
   8  * Copyright (C) 2017 Sebastian Lackner
   9  *
  10  * This library is free software; you can redistribute it and/or
  11  * modify it under the terms of the GNU Lesser General Public
  12  * License as published by the Free Software Foundation; either
  13  * version 2.1 of the License, or (at your option) any later version.
  14  *
  15  * This library is distributed in the hope that it will be useful,
  16  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  17  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  18  * Lesser General Public License for more details.
  19  *
  20  * You should have received a copy of the GNU Lesser General Public
  21  * License along with this library; if not, write to the Free Software
  22  * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301, USA
  23  */
  24
  25 #ifdef __APPLE__
  26
  27 #include "config.h"
  28
  29 #include <stdarg.h>
  30 #include <stdio.h>
  31 #include <stdlib.h>
  32 #include <string.h>
  33 #include <sys/types.h>
  34 #include <sys/stat.h>
  35 #include <fcntl.h>
  36 #include <sys/mman.h>
  37 #ifdef HAVE_SYS_SYSCALL_H
  38 # include <sys/syscall.h>
  39 #endif
  40 #include <unistd.h>
  41 #include <dlfcn.h>
  42 #ifdef HAVE_MACH_O_LOADER_H
  43 #include <mach/thread_status.h>
  44 #include <mach-o/loader.h>
  45 #include <mach-o/ldsyms.h>
  46 #endif
  47
  48 #include "wine/asm.h"
  49 #include "main.h"
  50
  51 #if defined(__x86_64__)
  52 /* Rosetta on Apple Silicon allocates memory starting at 0x100000000 (the 4GB line)
  53  * before the preloader runs, which prevents any nonrelocatable EXEs with that
  54  * base address from running.
  55  *
  56  * This empty linker section forces Rosetta's allocations (currently ~132 MB)
  57  * to start at 0x114000000, and they should end below 0x120000000.
  58  */
  59 __asm__(".zerofill WINE_4GB_RESERVE,WINE_4GB_RESERVE,___wine_4gb_reserve,0x14000000");
  60
  61 static const struct wine_preload_info zerofill_sections[] =
  62 {
  63     { (void *)0x000100000000, 0x14000000 },  /* WINE_4GB_RESERVE section */
  64     { 0, 0 }                                 /* end of list */
  65 };
  66 #else
  67 static const struct wine_preload_info zerofill_sections[] =
  68 {
  69     { 0, 0 }                                 /* end of list */
  70 };
  71 #endif
  72
  73 #ifndef LC_MAIN
  74 #define LC_MAIN 0x80000028
  75 struct entry_point_command
  76 {
  77     uint32_t cmd;
  78     uint32_t cmdsize;
  79     uint64_t entryoff;
  80     uint64_t stacksize;
  81 };
  82 #endif
  83
  84 static struct wine_preload_info preload_info[] =
  85 {
  86     /* On macOS, we allocate the low 64k area in two steps because PAGEZERO
  87      * might not always be available. */
  88 #ifdef __i386__
  89     { (void *)0x00000000, 0x00001000 },  /* first page */
  90     { (void *)0x00001000, 0x0000f000 },  /* low 64k */
  91     { (void *)0x00010000, 0x00100000 },  /* DOS area */
  92     { (void *)0x00110000, 0x67ef0000 },  /* low memory area */
  93     { (void *)0x7f000000, 0x03000000 },  /* top-down allocations + shared heap + virtual heap */
  94 #else  /* __i386__ */
  95     { (void *)0x000000010000, 0x00100000 },  /* DOS area */
  96     { (void *)0x000000110000, 0x67ef0000 },  /* low memory area */
  97     { (void *)0x00007ff00000, 0x000f0000 },  /* shared user data */
  98     { (void *)0x000100000000, 0x14000000 },  /* WINE_4GB_RESERVE section */
  99     { (void *)0x7ff000000000, 0x01ff0000 },  /* top-down allocations + virtual heap */
 100 #endif /* __i386__ */
 101     { 0, 0 },                            /* PE exe range set with WINEPRELOADRESERVE */
 102     { 0, 0 }                             /* end of list */
 103 };
 104
 105 /*
 106  * These functions are only called when file is compiled with -fstack-protector.
 107  * They are normally provided by libc's startup files, but since we
 108  * build the preloader with "-nostartfiles -nodefaultlibs", we have to
 109  * provide our own versions, otherwise the linker fails.
 110  */
 111 void *__stack_chk_guard = 0;
 112 void __stack_chk_fail_local(void) { return; }
 113 void __stack_chk_fail(void) { return; }
 114
 115 /*
 116  * When 'start' is called, stack frame looks like:
 117  *
 118  *             :
 119  *      | STRING AREA |
 120  *      +-------------+
 121  *      |      0      |
 122  *      +-------------+
 123  *      |  exec_path  | extra "apple" parameters start after NULL terminating env array
 124  *      +-------------+
 125  *      |      0      |
 126  *      +-------------+
 127  *      |    env[n]   |
 128  *      +-------------+
 129  *             :
 130  *             :
 131  *      +-------------+
 132  *      |    env[0]   |
 133  *      +-------------+
 134  *      |      0      |
 135  *      +-------------+
 136  *      | arg[argc-1] |
 137  *      +-------------+
 138  *             :
 139  *             :
 140  *      +-------------+
 141  *      |    arg[0]   |
 142  *      +-------------+
 143  *      |     argc    | argc is always 4 bytes long, even in 64-bit architectures
 144  *      +-------------+ <- sp
 145  *
 146  *      Where arg[i] and env[i] point into the STRING AREA
 147  *
 148  *  See also:
 149  *  macOS C runtime 'start':
 150  *  <https://github.com/apple-oss-distributions/Csu/blob/Csu-88/start.s>
 151  *
 152  *  macOS dyld '__dyld_start' (pre-dyld4):
 153  *  <https://github.com/apple-oss-distributions/dyld/blob/dyld-852.2/src/dyldStartup.s>
 154  */
 155
 156 #ifdef __i386__
 157
 158 static const size_t page_mask = 0xfff;
 159 #define target_mach_header      mach_header
 160 #define target_segment_command  segment_command
 161 #define TARGET_LC_SEGMENT       LC_SEGMENT
 162 #define target_thread_state_t   i386_thread_state_t
 163 #ifdef __DARWIN_UNIX03
 164 #define target_thread_ip(x)     (x)->__eip
 165 #else
 166 #define target_thread_ip(x)     (x)->eip
 167 #endif
 168
 169 #define SYSCALL_FUNC( name, nr ) \
 170     __ASM_GLOBAL_FUNC( name, \
 171                        "\tmovl $" #nr ",%eax\n" \
 172                        "\tint $0x80\n" \
 173                        "\tjnb 1f\n" \
 174                        "\tmovl $-1,%eax\n" \
 175                        "1:\tret\n" )
 176
 177 #define SYSCALL_NOERR( name, nr ) \
 178     __ASM_GLOBAL_FUNC( name, \
 179                        "\tmovl $" #nr ",%eax\n" \
 180                        "\tint $0x80\n" \
 181                        "\tret\n" )
 182
 183 __ASM_GLOBAL_FUNC( start,
 184                    __ASM_CFI("\t.cfi_undefined %eip\n")
 185                    /* The first 16 bytes are used as a function signature on i386 */
 186                    "\t.byte 0x6a,0x00\n"            /* pushl $0: push a zero for debugger end of frames marker */
 187                    "\t.byte 0x89,0xe5\n"            /* movl %esp,%ebp: pointer to base of kernel frame */
 188                    "\t.byte 0x83,0xe4,0xf0\n"       /* andl $-16,%esp: force SSE alignment */
 189                    "\t.byte 0x83,0xec,0x10\n"       /* subl $16,%esp: room for new argc, argv, & envp, SSE aligned */
 190                    "\t.byte 0x8b,0x5d,0x04\n"       /* movl 4(%ebp),%ebx: pickup argc in %ebx */
 191                    "\t.byte 0x89,0x5c,0x24,0x00\n"  /* movl %ebx,0(%esp): argc to reserved stack word */
 192
 193                    /* call wld_start(stack, &is_unix_thread) */
 194                    "\tleal 4(%ebp),%eax\n"
 195                    "\tmovl %eax,0(%esp)\n"          /* stack */
 196                    "\tleal 8(%esp),%eax\n"
 197                    "\tmovl %eax,4(%esp)\n"          /* &is_unix_thread */
 198                    "\tmovl $0,(%eax)\n"
 199                    "\tcall _wld_start\n"
 200
 201                    /* jmp based on is_unix_thread */
 202                    "\tcmpl $0,8(%esp)\n"
 203                    "\tjne 2f\n"
 204
 205                    "\tmovl 4(%ebp),%edi\n"          /* %edi = argc */
 206                    "\tleal 8(%ebp),%esi\n"          /* %esi = argv */
 207                    "\tleal 4(%esi,%edi,4),%edx\n"   /* %edx = env */
 208                    "\tmovl %edx,%ecx\n"
 209                    "1:\tmovl (%ecx),%ebx\n"
 210                    "\tadd $4,%ecx\n"
 211                    "\torl %ebx,%ebx\n"              /* look for the NULL ending the env[] array */
 212                    "\tjnz 1b\n"                     /* %ecx = apple data */
 213
 214                    /* LC_MAIN */
 215                    "\tmovl %edi,0(%esp)\n"          /* argc */
 216                    "\tmovl %esi,4(%esp)\n"          /* argv */
 217                    "\tmovl %edx,8(%esp)\n"          /* env */
 218                    "\tmovl %ecx,12(%esp)\n"         /* apple data */
 219                    "\tcall *%eax\n"                 /* call main(argc,argv,env,apple) */
 220                    "\tmovl %eax,(%esp)\n"           /* pass result from main() to exit() */
 221                    "\tcall _wld_exit\n"             /* need to use call to keep stack aligned */
 222                    "\thlt\n"
 223
 224                    /* LC_UNIXTHREAD */
 225                    "\t2:movl %ebp,%esp\n"           /* restore the unaligned stack pointer */
 226                    "\taddl $4,%esp\n"               /* remove the debugger end frame marker */
 227                    "\tmovl $0,%ebp\n"               /* restore ebp back to zero */
 228                    "\tjmpl *%eax\n" )               /* jump to the entry point */
 229
 230 #elif defined(__x86_64__)
 231
 232 static const size_t page_mask = 0xfff;
 233 #define target_mach_header      mach_header_64
 234 #define target_segment_command  segment_command_64
 235 #define TARGET_LC_SEGMENT       LC_SEGMENT_64
 236 #define target_thread_state_t   x86_thread_state64_t
 237 #ifdef __DARWIN_UNIX03
 238 #define target_thread_ip(x)     (x)->__rip
 239 #else
 240 #define target_thread_ip(x)     (x)->rip
 241 #endif
 242
 243 #define SYSCALL_FUNC( name, nr ) \
 244     __ASM_GLOBAL_FUNC( name, \
 245                        "\tmovq %rcx, %r10\n" \
 246                        "\tmovq $(" #nr "|0x2000000),%rax\n" \
 247                        "\tsyscall\n" \
 248                        "\tjnb 1f\n" \
 249                        "\tmovq $-1,%rax\n" \
 250                        "1:\tret\n" )
 251
 252 #define SYSCALL_NOERR( name, nr ) \
 253     __ASM_GLOBAL_FUNC( name, \
 254                        "\tmovq %rcx, %r10\n" \
 255                        "\tmovq $(" #nr "|0x2000000),%rax\n" \
 256                        "\tsyscall\n" \
 257                        "\tret\n" )
 258
 259 __ASM_GLOBAL_FUNC( start,
 260                    __ASM_CFI("\t.cfi_undefined %rip\n")
 261                    "\tpushq $0\n"                   /* push a zero for debugger end of frames marker */
 262                    "\tmovq %rsp,%rbp\n"             /* pointer to base of kernel frame */
 263                    "\tandq $-16,%rsp\n"             /* force SSE alignment */
 264                    "\tsubq $16,%rsp\n"              /* room for local variables */
 265
 266                    /* call wld_start(stack, &is_unix_thread) */
 267                    "\tleaq 8(%rbp),%rdi\n"          /* stack */
 268                    "\tmovq %rsp,%rsi\n"             /* &is_unix_thread */
 269                    "\tmovq $0,(%rsi)\n"
 270                    "\tcall _wld_start\n"
 271
 272                    /* jmp based on is_unix_thread */
 273                    "\tcmpl $0,0(%rsp)\n"
 274                    "\tjne 2f\n"
 275
 276                    /* LC_MAIN */
 277                    "\tmovq 8(%rbp),%rdi\n"          /* %rdi = argc */
 278                    "\tleaq 16(%rbp),%rsi\n"         /* %rsi = argv */
 279                    "\tleaq 8(%rsi,%rdi,8),%rdx\n"   /* %rdx = env */
 280                    "\tmovq %rdx,%rcx\n"
 281                    "1:\tmovq (%rcx),%r8\n"
 282                    "\taddq $8,%rcx\n"
 283                    "\torq %r8,%r8\n"                /* look for the NULL ending the env[] array */
 284                    "\tjnz 1b\n"                     /* %rcx = apple data */
 285
 286                    "\taddq $16,%rsp\n"              /* remove local variables */
 287                    "\tcall *%rax\n"                 /* call main(argc,argv,env,apple) */
 288                    "\tmovq %rax,%rdi\n"             /* pass result from main() to exit() */
 289                    "\tcall _wld_exit\n"             /* need to use call to keep stack aligned */
 290                    "\thlt\n"
 291
 292                    /* LC_UNIXTHREAD */
 293                    "\t2:movq %rbp,%rsp\n"           /* restore the unaligned stack pointer */
 294                    "\taddq $8,%rsp\n"               /* remove the debugger end frame marker */
 295                    "\tmovq $0,%rbp\n"               /* restore ebp back to zero */
 296                    "\tjmpq *%rax\n" )               /* jump to the entry point */
 297
 298 #else
 299 #error preloader not implemented for this CPU
 300 #endif
 301
 302 void wld_exit( int code ) __attribute__((noreturn));
 303 SYSCALL_NOERR( wld_exit, 1 /* SYS_exit */ );
 304
 305 ssize_t wld_write( int fd, const void *buffer, size_t len );
 306 SYSCALL_FUNC( wld_write, 4 /* SYS_write */ );
 307
 308 void *wld_mmap( void *start, size_t len, int prot, int flags, int fd, off_t offset );
 309 SYSCALL_FUNC( wld_mmap, 197 /* SYS_mmap */ );
 310
 311 void *wld_munmap( void *start, size_t len );
 312 SYSCALL_FUNC( wld_munmap, 73 /* SYS_munmap */ );
 313
 314 static intptr_t (*p_dyld_get_image_slide)( const struct target_mach_header* mh );
 315
 316 #define MAKE_FUNCPTR(f) static typeof(f) * p##f
 317 MAKE_FUNCPTR(dlopen);
 318 MAKE_FUNCPTR(dlsym);
 319 MAKE_FUNCPTR(dladdr);
 320 #undef MAKE_FUNCPTR
 321
 322 extern int _dyld_func_lookup( const char *dyld_func_name, void **address );
 323
 324 /* replacement for libc functions */
 325
 326 void * memmove( void *dst, const void *src, size_t len )
 327 {
 328     char *d = dst;
 329     const char *s = src;
 330     if (d < s)
 331         while (len--)
 332             *d++ = *s++;
 333     else
 334     {
 335         const char *lasts = s + (len-1);
 336         char *lastd = d + (len-1);
 337         while (len--)
 338             *lastd-- = *lasts--;
 339     }
 340     return dst;
 341 }
 342
 343 static int wld_strncmp( const char *str1, const char *str2, size_t len )
 344 {
 345     if (len <= 0) return 0;
 346     while ((--len > 0) && *str1 && (*str1 == *str2)) { str1++; str2++; }
 347     return *str1 - *str2;
 348 }
 349
 350 /*
 351  * wld_printf - just the basics
 352  *
 353  *  %x prints a hex number
 354  *  %s prints a string
 355  *  %p prints a pointer
 356  */
 357 static int wld_vsprintf(char *buffer, const char *fmt, va_list args )
 358 {
 359     static const char hex_chars[16] = "0123456789abcdef";
 360     const char *p = fmt;
 361     char *str = buffer;
 362     int i;
 363
 364     while( *p )
 365     {
 366         if( *p == '%' )
 367         {
 368             p++;
 369             if( *p == 'x' )
 370             {
 371                 unsigned int x = va_arg( args, unsigned int );
 372                 for (i = 2*sizeof(x) - 1; i >= 0; i--)
 373                     *str++ = hex_chars[(x>>(i*4))&0xf];
 374             }
 375             else if (p[0] == 'l' && p[1] == 'x')
 376             {
 377                 unsigned long x = va_arg( args, unsigned long );
 378                 for (i = 2*sizeof(x) - 1; i >= 0; i--)
 379                     *str++ = hex_chars[(x>>(i*4))&0xf];
 380                 p++;
 381             }
 382             else if( *p == 'p' )
 383             {
 384                 unsigned long x = (unsigned long)va_arg( args, void * );
 385                 for (i = 2*sizeof(x) - 1; i >= 0; i--)
 386                     *str++ = hex_chars[(x>>(i*4))&0xf];
 387             }
 388             else if( *p == 's' )
 389             {
 390                 char *s = va_arg( args, char * );
 391                 while(*s)
 392                     *str++ = *s++;
 393             }
 394             else if( *p == 0 )
 395                 break;
 396             p++;
 397         }
 398         *str++ = *p++;
 399     }
 400     *str = 0;
 401     return str - buffer;
 402 }
 403
 404 static __attribute__((format(printf,1,2))) void wld_printf(const char *fmt, ... )
 405 {
 406     va_list args;
 407     char buffer[256];
 408     int len;
 409
 410     va_start( args, fmt );
 411     len = wld_vsprintf(buffer, fmt, args );
 412     va_end( args );
 413     wld_write(2, buffer, len);
 414 }
 415
 416 static __attribute__((noreturn,format(printf,1,2))) void fatal_error(const char *fmt, ... )
 417 {
 418     va_list args;
 419     char buffer[256];
 420     int len;
 421
 422     va_start( args, fmt );
 423     len = wld_vsprintf(buffer, fmt, args );
 424     va_end( args );
 425     wld_write(2, buffer, len);
 426     wld_exit(1);
 427 }
 428
 429 static int preloader_overlaps_range( const void *start, const void *end )
 430 {
 431     intptr_t slide = p_dyld_get_image_slide(&_mh_execute_header);
 432     struct load_command *cmd = (struct load_command*)(&_mh_execute_header + 1);
 433     int i;
 434
 435     for (i = 0; i < _mh_execute_header.ncmds; ++i)
 436     {
 437         if (cmd->cmd == TARGET_LC_SEGMENT)
 438         {
 439             struct target_segment_command *seg = (struct target_segment_command*)cmd;
 440             const void *seg_start = (const void*)(seg->vmaddr + slide);
 441             const void *seg_end = (const char*)seg_start + seg->vmsize;
 442             static const char reserved_segname[] = "WINE_4GB_RESERVE";
 443
 444             if (!wld_strncmp( seg->segname, reserved_segname, sizeof(reserved_segname)-1 ))
 445                 continue;
 446
 447             if (end > seg_start && start <= seg_end)
 448             {
 449                 char segname[sizeof(seg->segname) + 1];
 450                 memcpy(segname, seg->segname, sizeof(seg->segname));
 451                 segname[sizeof(segname) - 1] = 0;
 452                 wld_printf( "WINEPRELOADRESERVE range %p-%p overlaps preloader %s segment %p-%p\n",
 453                              start, end, segname, seg_start, seg_end );
 454                 return 1;
 455             }
 456         }
 457         cmd = (struct load_command*)((char*)cmd + cmd->cmdsize);
 458     }
 459
 460     return 0;
 461 }
 462
 463 /*
 464  *  preload_reserve
 465  *
 466  * Reserve a range specified in string format
 467  */
 468 static void preload_reserve( const char *str )
 469 {
 470     const char *p;
 471     unsigned long result = 0;
 472     void *start = NULL, *end = NULL;
 473     int i, first = 1;
 474
 475     for (p = str; *p; p++)
 476     {
 477         if (*p >= '0' && *p <= '9') result = result * 16 + *p - '0';
 478         else if (*p >= 'a' && *p <= 'f') result = result * 16 + *p - 'a' + 10;
 479         else if (*p >= 'A' && *p <= 'F') result = result * 16 + *p - 'A' + 10;
 480         else if (*p == '-')
 481         {
 482             if (!first) goto error;
 483             start = (void *)(result & ~page_mask);
 484             result = 0;
 485             first = 0;
 486         }
 487         else goto error;
 488     }
 489     if (!first) end = (void *)((result + page_mask) & ~page_mask);
 490     else if (result) goto error;  /* single value '0' is allowed */
 491
 492     /* sanity checks */
 493     if (end <= start || preloader_overlaps_range(start, end))
 494         start = end = NULL;
 495
 496     /* check for overlap with low memory areas */
 497     for (i = 0; preload_info[i].size; i++)
 498     {
 499         if ((char *)preload_info[i].addr > (char *)0x00110000) break;
 500         if ((char *)end <= (char *)preload_info[i].addr + preload_info[i].size)
 501         {
 502             start = end = NULL;
 503             break;
 504         }
 505         if ((char *)start < (char *)preload_info[i].addr + preload_info[i].size)
 506             start = (char *)preload_info[i].addr + preload_info[i].size;
 507     }
 508
 509     while (preload_info[i].size) i++;
 510     preload_info[i].addr = start;
 511     preload_info[i].size = (char *)end - (char *)start;
 512     return;
 513
 514 error:
 515     fatal_error( "invalid WINEPRELOADRESERVE value '%s'\n", str );
 516 }
 517
 518 /* remove a range from the preload list */
 519 static void remove_preload_range( int i )
 520 {
 521     while (preload_info[i].size)
 522     {
 523         preload_info[i].addr = preload_info[i+1].addr;
 524         preload_info[i].size = preload_info[i+1].size;
 525         i++;
 526     }
 527 }
 528
 529 static void *get_entry_point( struct target_mach_header *mh, intptr_t slide, int *unix_thread )
 530 {
 531     struct entry_point_command *entry;
 532     target_thread_state_t *state;
 533     struct load_command *cmd;
 534     int i;
 535
 536     /* try LC_MAIN first */
 537     cmd = (struct load_command *)(mh + 1);
 538     for (i = 0; i < mh->ncmds; i++)
 539     {
 540         if (cmd->cmd == LC_MAIN)
 541         {
 542             *unix_thread = FALSE;
 543             entry = (struct entry_point_command *)cmd;
 544             return (char *)mh + entry->entryoff;
 545         }
 546         cmd = (struct load_command *)((char *)cmd + cmd->cmdsize);
 547     }
 548
 549     /* then try LC_UNIXTHREAD */
 550     cmd = (struct load_command *)(mh + 1);
 551     for (i = 0; i < mh->ncmds; i++)
 552     {
 553         if (cmd->cmd == LC_UNIXTHREAD)
 554         {
 555             *unix_thread = TRUE;
 556             state = (target_thread_state_t *)((char *)cmd + 16);
 557             return (void *)(target_thread_ip(state) + slide);
 558         }
 559         cmd = (struct load_command *)((char *)cmd + cmd->cmdsize);
 560     }
 561
 562     return NULL;
 563 };
 564
 565 static int is_zerofill( struct wine_preload_info *info )
 566 {
 567     int i;
 568
 569     for (i = 0; zerofill_sections[i].size; i++)
 570     {
 571         if ((zerofill_sections[i].addr == info->addr) &&
 572             (zerofill_sections[i].size == info->size))
 573             return 1;
 574     }
 575     return 0;
 576 }
 577
 578 static int map_region( struct wine_preload_info *info )
 579 {
 580     int flags = MAP_PRIVATE | MAP_ANON;
 581     void *ret;
 582
 583     if (!info->addr || is_zerofill( info )) flags |= MAP_FIXED;
 584
 585     ret = wld_mmap( info->addr, info->size, PROT_NONE, flags, -1, 0 );
 586     if (ret == info->addr) return 1;
 587     if (ret != (void *)-1) wld_munmap( ret, info->size );
 588
 589     /* don't warn for zero page */
 590     if (info->addr >= (void *)0x1000)
 591         wld_printf( "preloader: Warning: failed to reserve range %p-%p\n",
 592                     info->addr, (char *)info->addr + info->size );
 593     return 0;
 594 }
 595
 596 static inline void get_dyld_func( const char *name, void **func )
 597 {
 598     _dyld_func_lookup( name, func );
 599     if (!*func) fatal_error( "Failed to get function pointer for %s\n", name );
 600 }
 601
 602 #define LOAD_POSIX_DYLD_FUNC(f) get_dyld_func( "__dyld_" #f, (void **)&p##f )
 603 #define LOAD_MACHO_DYLD_FUNC(f) get_dyld_func( "_" #f, (void **)&p##f )
 604
 605 static void fixup_stack( void *stack )
 606 {
 607     int *pargc;
 608     char **argv, **env_new;
 609     static char dummyvar[] = "WINEPRELOADERDUMMYVAR=1";
 610
 611     pargc = stack;
 612     argv = (char **)pargc + 1;
 613
 614     /* decrement argc, and "remove" argv[0] */
 615     *pargc = *pargc - 1;
 616     memmove( &argv[0], &argv[1], (*pargc + 1) * sizeof(char *) );
 617
 618     env_new = &argv[*pargc-1] + 2;
 619     /* In the launched binary on some OSes, _NSGetEnviron() returns
 620      * the original 'environ' pointer, so env_new[0] would be ignored.
 621      * Put a dummy variable in env_new[0], so nothing is lost in this case.
 622      */
 623     env_new[0] = dummyvar;
 624 }
 625
 626 static void set_program_vars( void *stack, void *mod )
 627 {
 628     int *pargc;
 629     char **argv, **env;
 630     int *wine_NXArgc = pdlsym( mod, "NXArgc" );
 631     char ***wine_NXArgv = pdlsym( mod, "NXArgv" );
 632     char ***wine_environ = pdlsym( mod, "environ" );
 633
 634     pargc = stack;
 635     argv = (char **)pargc + 1;
 636     env = &argv[*pargc-1] + 2;
 637
 638     if (wine_NXArgc)
 639         *wine_NXArgc = *pargc;
 640     else
 641         wld_printf( "preloader: Warning: failed to set NXArgc\n" );
 642
 643     if (wine_NXArgv)
 644         *wine_NXArgv = argv;
 645     else
 646         wld_printf( "preloader: Warning: failed to set NXArgv\n" );
 647
 648     if (wine_environ)
 649         *wine_environ = env;
 650     else
 651         wld_printf( "preloader: Warning: failed to set environ\n" );
 652 }
 653
 654 void *wld_start( void *stack, int *is_unix_thread )
 655 {
 656     struct wine_preload_info builtin_dlls = { (void *)0x7a000000, 0x02000000 };
 657     struct wine_preload_info **wine_main_preload_info;
 658     char **argv, **p, *reserve = NULL;
 659     struct target_mach_header *mh;
 660     void *mod, *entry;
 661     int *pargc, i;
 662     Dl_info info;
 663
 664     pargc = stack;
 665     argv = (char **)pargc + 1;
 666     if (*pargc < 2) fatal_error( "Usage: %s wine_binary [args]\n", argv[0] );
 667
 668     /* skip over the parameters */
 669     p = argv + *pargc + 1;
 670
 671     /* skip over the environment */
 672     while (*p)
 673     {
 674         static const char res[] = "WINEPRELOADRESERVE=";
 675         if (!wld_strncmp( *p, res, sizeof(res)-1 )) reserve = *p + sizeof(res) - 1;
 676         p++;
 677     }
 678
 679     LOAD_POSIX_DYLD_FUNC( dlopen );
 680     LOAD_POSIX_DYLD_FUNC( dlsym );
 681     LOAD_POSIX_DYLD_FUNC( dladdr );
 682     LOAD_MACHO_DYLD_FUNC( _dyld_get_image_slide );
 683
 684     /* reserve memory that Wine needs */
 685     if (reserve) preload_reserve( reserve );
 686     for (i = 0; preload_info[i].size; i++)
 687     {
 688         if (!map_region( &preload_info[i] ))
 689         {
 690             remove_preload_range( i );
 691             i--;
 692         }
 693     }
 694
 695     if (!map_region( &builtin_dlls ))
 696         builtin_dlls.size = 0;
 697
 698     /* load the main binary */
 699     if (!(mod = pdlopen( argv[1], RTLD_NOW )))
 700         fatal_error( "%s: could not load binary\n", argv[1] );
 701
 702     if (builtin_dlls.size)
 703         wld_munmap( builtin_dlls.addr, builtin_dlls.size );
 704
 705     /* store pointer to the preload info into the appropriate main binary variable */
 706     wine_main_preload_info = pdlsym( mod, "wine_main_preload_info" );
 707     if (wine_main_preload_info) *wine_main_preload_info = preload_info;
 708     else wld_printf( "wine_main_preload_info not found\n" );
 709
 710     if (!pdladdr( wine_main_preload_info, &info ) || !(mh = info.dli_fbase))
 711         fatal_error( "%s: could not find mach header\n", argv[1] );
 712     if (!(entry = get_entry_point( mh, p_dyld_get_image_slide(mh), is_unix_thread )))
 713         fatal_error( "%s: could not find entry point\n", argv[1] );
 714
 715     /* decrement argc and "remove" argv[0] */
 716     fixup_stack(stack);
 717
 718     /* Set NXArgc, NXArgv, and environ in the new binary.
 719      * On different configurations these were either NULL/0 or still had their
 720      * values from this preloader's launch.
 721      *
 722      * In particular, environ was not being updated, resulting in environ[0] being lost.
 723      * And for LC_UNIXTHREAD binaries on Monterey and later, environ was just NULL.
 724      */
 725     set_program_vars( stack, mod );
 726
 727     return entry;
 728 }
 729
 730 #endif /* __APPLE__ */