loader-OSX_Preloader: Allocate pagezero for main wine binary.

This change should fix compatibility with old versions of macOS.
Thanks to Gijs Vermeulen for help with debugging and testing this patch.

Old versions of libsystem_c.dylib crash while running initializers when
the application does not contain a PAGEZERO section. This is probably
caused by an incorrect comparison against NULL instead of (void *)-1.

Unfortunately, when we just add a PAGEZERO section, we trigger the next
bug - no matter if we actually use the page at address (void *)0 or not,
it will not be used because the relocation code tries to find a memory
hole of size (highAddr - lowAddr) ~ 2GB.

We might be able to workaround this issue by manually reordering the
sections in the main executable, but for now lets just drop the fixed
image base. Please note that this introduces a risk of conflicts with
builtin DLLs, which will be resolved in the next patch.

patches/loader-OSX_Preloader/0002-loader-Implement-preloader-for-Mac-OS.patch

@@ -1,17 +1,17 @@
-From c216ca6977f3b2b32aadc0155f30f5bcf27364b3 Mon Sep 17 00:00:00 2001
+From 121236d997013c4f7c52ad9384bdf727396d1c55 Mon Sep 17 00:00:00 2001
 From: Sebastian Lackner <sebastian@fds-team.de>
 Date: Mon, 12 Jun 2017 00:16:08 +0200
 Subject: loader: Implement preloader for Mac OS.
 
 ---
  Makefile.in          |   1 +
- configure.ac         |  32 ++++-
+ configure.ac         |  30 +++-
  dlls/ntdll/virtual.c |   2 -
  libs/wine/config.c   |   2 +-
  loader/Makefile.in   |   4 +-
  loader/main.c        |  44 ++----
- loader/preloader.c   | 399 +++++++++++++++++++++++++++++++++++++++++++++++++--
- 7 files changed, 433 insertions(+), 51 deletions(-)
+ loader/preloader.c   | 402 +++++++++++++++++++++++++++++++++++++++++++++++++--
+ 7 files changed, 433 insertions(+), 52 deletions(-)
 
 diff --git a/Makefile.in b/Makefile.in
 index 22b2ae72305..29b6cbdd535 100644
@@ -26,10 +26,10 @@ index 22b2ae72305..29b6cbdd535 100644
  LIBWINE_IMPORTLIB   = @LIBWINE_IMPORTLIB@
  LIBWINE_INSTALL_LIB = @LIBWINE_INSTALL_LIB@
 diff --git a/configure.ac b/configure.ac
-index 5aaa20c22b6..433e7fa959c 100644
+index 0f2221963dc..86c3276d28e 100644
 --- a/configure.ac
 +++ b/configure.ac
-@@ -709,6 +709,7 @@ AC_SUBST(LDRPATH_INSTALL,"")
+@@ -683,6 +683,7 @@ AC_SUBST(LDRPATH_INSTALL,"")
  AC_SUBST(LDRPATH_LOCAL,"")
  AC_SUBST(LDEXECFLAGS,"")
  AC_SUBST(WINELOADER_LDFLAGS,"")
@@ -37,13 +37,13 @@ index 5aaa20c22b6..433e7fa959c 100644
  LIBEXT="so"
  DLLEXT=".so"
  IMPLIBEXT="def"
-@@ -767,9 +768,26 @@ case $host_os in
+@@ -741,9 +742,24 @@ case $host_os in
      AC_SUBST(APPLICATIONSERVICES_LIBS,"-framework ApplicationServices")
      AC_SUBST(CORESERVICES_LIBS,"-framework CoreServices")
      AC_SUBST(APPKIT_LIBS,"-framework AppKit")
 -    WINELOADER_LDFLAGS="-image_base 0x7bf00000 -Wl,-pagezero_size,0x1000,-segaddr,WINE_DOS,0x00001000,-segaddr,WINE_SHAREDHEAP,0x7f000000,-sectcreate,__TEXT,__info_plist,wine_info.plist"
 +
-+    WINELOADER_LDFLAGS="-Wl,-image_base,0x7bf00000,-pie,-sectcreate,__TEXT,__info_plist,wine_info.plist"
++    WINELOADER_LDFLAGS="-Wl,-pie,-pagezero_size,0x1000,-sectcreate,__TEXT,__info_plist,wine_info.plist"
 +    WINE_TRY_CFLAGS([-fPIC -Wl,--export-dynamic],
 +                    [WINELOADER_LDFLAGS="-Wl,--export-dynamic $WINELOADER_LDFLAGS"])
 +
@@ -56,17 +56,15 @@ index 5aaa20c22b6..433e7fa959c 100644
 +
 +    case $host_cpu in
 +      *i[[3456789]]86*)
-+        WINELOADER_LDFLAGS="-Wl,-pagezero_size,0x0 $WINELOADER_LDFLAGS"
 +        WINEPRELOADER_LDFLAGS="-Wl,-pagezero_size,0x0 $WINEPRELOADER_LDFLAGS" ;;
 +      *x86_64*)
-+        WINELOADER_LDFLAGS="-Wl,-pagezero_size,0x1000 $WINELOADER_LDFLAGS"
 +        WINEPRELOADER_LDFLAGS="-Wl,-pagezero_size,0x1000 $WINEPRELOADER_LDFLAGS" ;;
 +    esac
 +
      if test "$ac_cv_header_DiskArbitration_DiskArbitration_h" = "yes"
      then
          dnl DiskArbitration API is not public on Darwin < 8.0, use it only if header found
-@@ -882,6 +900,7 @@ case $host_os in
+@@ -856,6 +872,7 @@ case $host_os in
      enable_wineandroid_drv=${enable_wineandroid_drv:-yes}
      WINE_TRY_CFLAGS([-fPIC -Wl,--export-dynamic],
                      [WINELOADER_LDFLAGS="-Wl,--export-dynamic"])
@@ -74,7 +72,7 @@ index 5aaa20c22b6..433e7fa959c 100644
      WINE_TRY_CFLAGS([-fPIC -Wl,--rpath,\$ORIGIN/../lib],
                      [LDRPATH_INSTALL="-Wl,--rpath,\\\$\$ORIGIN/\`\$(MAKEDEP) -R \${bindir} \${libdir}\`"
                       LDRPATH_LOCAL="-Wl,--rpath,\\\$\$ORIGIN/\$(top_builddir)/libs/wine"],
-@@ -926,6 +945,7 @@ case $host_os in
+@@ -900,6 +917,7 @@ case $host_os in
  
        WINE_TRY_CFLAGS([-fPIC -Wl,--export-dynamic],
                        [WINELOADER_LDFLAGS="-Wl,--export-dynamic"])
@@ -82,7 +80,7 @@ index 5aaa20c22b6..433e7fa959c 100644
  
        WINE_TRY_CFLAGS([-fPIC -Wl,--rpath,\$ORIGIN/../lib],
                        [LDRPATH_INSTALL="-Wl,--rpath,\\\$\$ORIGIN/\`\$(MAKEDEP) -R \${bindir} \${libdir}\`:\$(DESTDIR)\${libdir}"
-@@ -2085,6 +2105,14 @@ case $host_os in
+@@ -2009,6 +2027,14 @@ case $host_os in
          ;;
      esac
      ;;
@@ -224,7 +222,7 @@ index 13740c7b3c5..5212e3f0798 100644
  
      wine_init( argc, argv, error, sizeof(error) );
 diff --git a/loader/preloader.c b/loader/preloader.c
-index 5e6add7830f..a18313d495c 100644
+index 5e6add7830f..2149d55f0d7 100644
 --- a/loader/preloader.c
 +++ b/loader/preloader.c
 @@ -4,6 +4,8 @@
@@ -257,12 +255,22 @@ index 5e6add7830f..a18313d495c 100644
  #ifndef MAP_COPY
  #define MAP_COPY MAP_PRIVATE
  #endif
-@@ -117,12 +118,38 @@ static struct wine_preload_info preload_info[] =
+@@ -109,7 +110,8 @@
+ static struct wine_preload_info preload_info[] =
+ {
+ #ifdef __i386__
+-    { (void *)0x00000000, 0x00010000 },  /* low 64k */
++    { (void *)0x00000000, 0x00001000 },  /* first page */
++    { (void *)0x00001000, 0x0000f000 },  /* low 64k */
+     { (void *)0x00010000, 0x00100000 },  /* DOS area */
+     { (void *)0x00110000, 0x67ef0000 },  /* low memory area */
+     { (void *)0x7f000000, 0x03000000 },  /* top-down allocations + shared heap + virtual heap */
+@@ -117,12 +119,38 @@ static struct wine_preload_info preload_info[] =
      { (void *)0x000000010000, 0x00100000 },  /* DOS area */
      { (void *)0x000000110000, 0x67ef0000 },  /* low memory area */
      { (void *)0x00007ff00000, 0x000f0000 },  /* shared user data */
 +#ifdef __APPLE__
-+    /* address below exceeds maximum allowed user space address in mac os */
++    /* address below exceeds maximum allowed user space address in macOS */
 +    { (void *)0x7fff40000000, 0x01ff0000 },  /* top-down allocations + virtual heap */
 +#else
      { (void *)0x7ffffe000000, 0x01ff0000 },  /* top-down allocations + virtual heap */
@@ -296,7 +304,7 @@ index 5e6add7830f..a18313d495c 100644
  /* debugging */
  #undef DUMP_SEGMENTS
  #undef DUMP_AUX_INFO
-@@ -168,6 +195,8 @@ struct wld_auxv
+@@ -168,6 +196,8 @@ struct wld_auxv
      } a_un;
  };
  
@@ -305,7 +313,7 @@ index 5e6add7830f..a18313d495c 100644
  /*
   * The __bb_init_func is an empty function only called when file is
   * compiled with gcc flags "-fprofile-arcs -ftest-coverage".  This
-@@ -182,6 +211,196 @@ void *__stack_chk_guard = 0;
+@@ -182,6 +212,196 @@ void *__stack_chk_guard = 0;
  void __stack_chk_fail_local(void) { return; }
  void __stack_chk_fail(void) { return; }
  
@@ -502,7 +510,7 @@ index 5e6add7830f..a18313d495c 100644
  #ifdef __i386__
  
  /* data for setting up the glibc-style thread-local storage in %gs */
-@@ -458,16 +677,17 @@ SYSCALL_NOERR( wld_getegid, 108 /* SYS_getegid */ );
+@@ -458,16 +678,17 @@ SYSCALL_NOERR( wld_getegid, 108 /* SYS_getegid */ );
  #else
  #error preloader not implemented for this CPU
  #endif
@@ -522,7 +530,7 @@ index 5e6add7830f..a18313d495c 100644
  {
      if (len <= 0) return 0;
      while ((--len > 0) && *str1 && (*str1 == *str2)) { str1++; str2++; }
-@@ -560,6 +780,8 @@ static __attribute__((noreturn,format(printf,1,2))) void fatal_error(const char
+@@ -560,6 +781,8 @@ static __attribute__((noreturn,format(printf,1,2))) void fatal_error(const char
      wld_exit(1);
  }
  
@@ -531,7 +539,7 @@ index 5e6add7830f..a18313d495c 100644
  #ifdef DUMP_AUX_INFO
  /*
   *  Dump interesting bits of the ELF auxv_t structure that is passed
-@@ -1039,6 +1261,8 @@ found:
+@@ -1039,6 +1262,8 @@ found:
      return (void *)(symtab[idx].st_value + map->l_addr);
  }
  
@@ -540,7 +548,7 @@ index 5e6add7830f..a18313d495c 100644
  /*
   *  preload_reserve
   *
-@@ -1070,6 +1294,7 @@ static void preload_reserve( const char *str )
+@@ -1070,6 +1295,7 @@ static void preload_reserve( const char *str )
  
      /* sanity checks */
      if (end <= start) start = end = NULL;
@@ -548,7 +556,7 @@ index 5e6add7830f..a18313d495c 100644
      else if ((char *)end > preloader_start &&
               (char *)start <= preloader_end)
      {
-@@ -1077,6 +1302,7 @@ static void preload_reserve( const char *str )
+@@ -1077,6 +1303,7 @@ static void preload_reserve( const char *str )
                       start, end, preloader_start, preloader_end );
          start = end = NULL;
      }
@@ -556,7 +564,7 @@ index 5e6add7830f..a18313d495c 100644
  
      /* check for overlap with low memory areas */
      for (i = 0; preload_info[i].size; i++)
-@@ -1101,7 +1327,7 @@ error:
+@@ -1101,7 +1328,7 @@ error:
  }
  
  /* check if address is in one of the reserved ranges */
@@ -565,7 +573,7 @@ index 5e6add7830f..a18313d495c 100644
  {
      int i;
  
-@@ -1125,6 +1351,159 @@ static void remove_preload_range( int i )
+@@ -1125,6 +1352,159 @@ static void remove_preload_range( int i )
      }
  }
  
@@ -725,7 +733,7 @@ index 5e6add7830f..a18313d495c 100644
  /*
   *  is_in_preload_range
   *
-@@ -1293,3 +1672,5 @@ void* wld_start( void **stack )
+@@ -1293,3 +1673,5 @@ void* wld_start( void **stack )
  
      return (void *)ld_so_map.l_entry;
  }