dlls/winecrt0/dll_soinit.c

   1 /*
   2  * Initialization code for .so modules
   3  *
   4  * Copyright (C) 2020 Alexandre Julliard
   5  *
   6  * This library is free software; you can redistribute it and/or
   7  * modify it under the terms of the GNU Lesser General Public
   8  * License as published by the Free Software Foundation; either
   9  * version 2.1 of the License, or (at your option) any later version.
  10  *
  11  * This library is distributed in the hope that it will be useful,
  12  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  14  * Lesser General Public License for more details.
  15  *
  16  * You should have received a copy of the GNU Lesser General Public
  17  * License along with this library; if not, write to the Free Software
  18  * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301, USA
  19  */
  20
  21 #if 0
  22 #pragma makedep unix
  23 #endif
  24
  25 #include "config.h"
  26
  27 #include <stdarg.h>
  28 #include <stdio.h>
  29 #include <string.h>
  30 #include <stdlib.h>
  31 #include <sys/types.h>
  32 #include <sys/stat.h>
  33 #include <unistd.h>
  34 #include <dlfcn.h>
  35 #ifdef HAVE_ELF_H
  36 # include <elf.h>
  37 #endif
  38 #ifdef HAVE_LINK_H
  39 # include <link.h>
  40 #endif
  41 #include "windef.h"
  42
  43
  44 #ifdef __FreeBSD__
  45 /* The PT_LOAD segments are sorted in increasing order, and the first
  46  * starts at the beginning of the ELF file. By parsing the file, we can
  47  * find that first PT_LOAD segment, from which we can find the base
  48  * address it wanted, and knowing mapbase where the binary was actually
  49  * loaded, use them to work out the relocbase offset. */
  50 static BOOL get_relocbase(caddr_t mapbase, caddr_t *relocbase)
  51 {
  52     Elf_Half i;
  53 #ifdef _WIN64
  54     const Elf64_Ehdr *elf_header = (Elf64_Ehdr*) mapbase;
  55 #else
  56     const Elf32_Ehdr *elf_header = (Elf32_Ehdr*) mapbase;
  57 #endif
  58     const Elf_Phdr *prog_header = (const Elf_Phdr *)(mapbase + elf_header->e_phoff);
  59
  60     for (i = 0; i < elf_header->e_phnum; i++)
  61     {
  62          if (prog_header->p_type == PT_LOAD)
  63          {
  64              caddr_t desired_base = (caddr_t)((prog_header->p_vaddr / prog_header->p_align) * prog_header->p_align);
  65              *relocbase = (caddr_t) (mapbase - desired_base);
  66              return TRUE;
  67          }
  68          prog_header++;
  69     }
  70     return FALSE;
  71 }
  72 #endif
  73
  74
  75 /*************************************************************************
  76  *              __wine_init_so_dll
  77  */
  78 void __wine_init_so_dll(void)
  79 {
  80 #if defined(HAVE_DLADDR1) || (defined(HAVE_DLINFO) && defined(RTLD_SELF))
  81     struct link_map *map;
  82     void (*init_func)(int, char **, char **) = NULL;
  83     void (**init_array)(int, char **, char **) = NULL;
  84     long i, init_arraysz = 0;
  85 #ifdef _WIN64
  86     const Elf64_Dyn *dyn;
  87 #else
  88     const Elf32_Dyn *dyn;
  89 #endif
  90
  91 #ifdef HAVE_DLADDR1
  92     Dl_info info;
  93     if (!dladdr1( __wine_init_so_dll, &info, (void **)&map, RTLD_DL_LINKMAP )) return;
  94 #else
  95     if (dlinfo( RTLD_SELF, RTLD_DI_LINKMAP, &map )) return;
  96 #endif
  97
  98     for (dyn = map->l_ld; dyn->d_tag; dyn++)
  99     {
 100         caddr_t relocbase = (caddr_t)map->l_addr;
 101
 102 #ifdef __FreeBSD__
 103         /* On older FreeBSD versions, l_addr was the absolute load address, now it's the relocation offset. */
 104         if (offsetof(struct link_map, l_addr) == 0)
 105             if (!get_relocbase(map->l_addr, &relocbase))
 106                 return;
 107 #endif
 108         switch (dyn->d_tag)
 109         {
 110         case 0x60009994: init_array = (void *)(relocbase + dyn->d_un.d_val); break;
 111         case 0x60009995: init_arraysz = dyn->d_un.d_val; break;
 112         case 0x60009996: init_func = (void *)(relocbase + dyn->d_un.d_val); break;
 113         }
 114     }
 115
 116     if (init_func) init_func( 0, NULL, NULL );
 117
 118     if (init_array)
 119         for (i = 0; i < init_arraysz / sizeof(*init_array); i++)
 120             init_array[i]( 0, NULL, NULL );
 121 #endif
 122 }