release/src-rt-6.x.4708/toolchains/hndtools-arm-linux-2.6.36-uclibc-4.5.3/arm-brcm-linux-uclibcgnueabi/sysroot/usr/include/link.h

   1 /* Data structure for communication from the run-time dynamic linker for
   2    loaded ELF shared objects.
   3    Copyright (C) 1995-2001, 2004, 2005, 2006, 2010 Free Software Foundation, Inc.
   4    This file is part of the GNU C Library.
   5
   6    The GNU C 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    The GNU C 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 the GNU C Library; if not, write to the Free
  18    Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
  19    02111-1307 USA.  */
  20
  21 #ifndef _LINK_H
  22 #define _LINK_H 1
  23
  24 #include <features.h>
  25 #include <elf.h>
  26 #ifdef __HAVE_SHARED__
  27 #include <dlfcn.h>
  28 #endif
  29 #include <sys/types.h>
  30
  31 /* We use this macro to refer to ELF types independent of the native wordsize.
  32    `ElfW(TYPE)' is used in place of `Elf32_TYPE' or `Elf64_TYPE'.  */
  33 #define ElfW(type)      _ElfW (Elf, __ELF_NATIVE_CLASS, type)
  34 #define _ElfW(e,w,t)    _ElfW_1 (e, w, _##t)
  35 #define _ElfW_1(e,w,t)  e##w##t
  36
  37 #include <bits/elfclass.h>              /* Defines __ELF_NATIVE_CLASS.  */
  38
  39 /* Rendezvous structure used by the run-time dynamic linker to communicate
  40    details of shared object loading to the debugger.  If the executable's
  41    dynamic section has a DT_DEBUG element, the run-time linker sets that
  42    element's value to the address where this structure can be found.  */
  43
  44 struct r_debug
  45   {
  46     int r_version;              /* Version number for this protocol.  */
  47
  48     struct link_map *r_map;     /* Head of the chain of loaded objects.  */
  49
  50     /* This is the address of a function internal to the run-time linker,
  51        that will always be called when the linker begins to map in a
  52        library or unmap it, and again when the mapping change is complete.
  53        The debugger can set a breakpoint at this address if it wants to
  54        notice shared object mapping changes.  */
  55     ElfW(Addr) r_brk;
  56     enum
  57       {
  58         /* This state value describes the mapping change taking place when
  59            the `r_brk' address is called.  */
  60         RT_CONSISTENT,          /* Mapping change is complete.  */
  61         RT_ADD,                 /* Beginning to add a new object.  */
  62         RT_DELETE               /* Beginning to remove an object mapping.  */
  63       } r_state;
  64
  65     ElfW(Addr) r_ldbase;        /* Base address the linker is loaded at.  */
  66   };
  67
  68 /* This is the instance of that structure used by the dynamic linker.  */
  69 extern struct r_debug _r_debug;
  70
  71 /* This symbol refers to the "dynamic structure" in the `.dynamic' section
  72    of whatever module refers to `_DYNAMIC'.  So, to find its own
  73    `struct r_debug', a program could do:
  74      for (dyn = _DYNAMIC; dyn->d_tag != DT_NULL; ++dyn)
  75        if (dyn->d_tag == DT_DEBUG)
  76          r_debug = (struct r_debug *) dyn->d_un.d_ptr;
  77    */
  78 extern ElfW(Dyn) _DYNAMIC[];
  79
  80 #ifdef __FDPIC__
  81 # include <bits/elf-fdpic.h>
  82 #endif
  83 #ifdef __DSBT__
  84 # include <bits/elf-dsbt.h>
  85 #endif
  86
  87 /* Structure describing a loaded shared object.  The `l_next' and `l_prev'
  88    members form a chain of all the shared objects loaded at startup.
  89
  90    These data structures exist in space used by the run-time dynamic linker;
  91    modifying them may have disastrous results.  */
  92
  93 struct link_map
  94   {
  95     /* These first few members are part of the protocol with the debugger.
  96        This is the same format used in SVR4.  */
  97
  98 #ifdef __FDPIC__
  99     struct elf32_fdpic_loadaddr l_addr;
 100 #else
 101 #ifdef __DSBT__
 102     struct elf32_dsbt_loadaddr l_addr;
 103 #else
 104     ElfW(Addr) l_addr;          /* Base address shared object is loaded at.  */
 105 #endif
 106 #endif
 107     char *l_name;               /* Absolute file name object was found in.  */
 108     ElfW(Dyn) *l_ld;            /* Dynamic section of the shared object.  */
 109     struct link_map *l_next, *l_prev; /* Chain of loaded objects.  */
 110
 111 #if defined(USE_TLS) && USE_TLS
 112     /* Thread-local storage related info.  */
 113
 114     /* Start of the initialization image.  */
 115     void *l_tls_initimage;
 116     /* Size of the initialization image.  */
 117     size_t l_tls_initimage_size;
 118     /* Size of the TLS block.  */
 119     size_t l_tls_blocksize;
 120     /* Alignment requirement of the TLS block.  */
 121     size_t l_tls_align;
 122     /* Offset of first byte module alignment.  */
 123     size_t l_tls_firstbyte_offset;
 124 # ifndef NO_TLS_OFFSET
 125 #  define NO_TLS_OFFSET 0
 126 # endif
 127     /* For objects present at startup time: offset in the static TLS block.  */
 128     ptrdiff_t l_tls_offset;
 129     /* Index of the module in the dtv array.  */
 130     size_t l_tls_modid;
 131     /* Nonzero if _dl_init_static_tls should be called for this module */
 132     unsigned int l_need_tls_init:1;
 133 #endif
 134   };
 135
 136 #ifdef __USE_GNU
 137
 138 #if 0
 139 /* Version numbers for la_version handshake interface.  */
 140 #define LAV_CURRENT     1
 141
 142 /* Activity types signaled through la_activity.  */
 143 enum
 144   {
 145     LA_ACT_CONSISTENT,          /* Link map consistent again.  */
 146     LA_ACT_ADD,                 /* New object will be added.  */
 147     LA_ACT_DELETE               /* Objects will be removed.  */
 148   };
 149
 150 /* Values representing origin of name for dynamic loading.  */
 151 enum
 152   {
 153     LA_SER_ORIG = 0x01,         /* Original name.  */
 154     LA_SER_LIBPATH = 0x02,      /* Directory from LD_LIBRARY_PATH.  */
 155     LA_SER_RUNPATH = 0x04,      /* Directory from RPATH/RUNPATH.  */
 156     LA_SER_CONFIG = 0x08,       /* Found through ldconfig.  */
 157     LA_SER_DEFAULT = 0x40,      /* Default directory.  */
 158     LA_SER_SECURE = 0x80        /* Unused.  */
 159   };
 160
 161 /* Values for la_objopen return value.  */
 162 enum
 163   {
 164     LA_FLG_BINDTO = 0x01,       /* Audit symbols bound to this object.  */
 165     LA_FLG_BINDFROM = 0x02      /* Audit symbols bound from this object.  */
 166   };
 167
 168 /* Values for la_symbind flags parameter.  */
 169 enum
 170   {
 171     LA_SYMB_NOPLTENTER = 0x01,  /* la_pltenter will not be called.  */
 172     LA_SYMB_NOPLTEXIT = 0x02,   /* la_pltexit will not be called.  */
 173     LA_SYMB_STRUCTCALL = 0x04,  /* Return value is a structure.  */
 174     LA_SYMB_DLSYM = 0x08,       /* Binding due to dlsym call.  */
 175     LA_SYMB_ALTVALUE = 0x10     /* Value has been changed by a previous
 176                                    la_symbind call.  */
 177   };
 178 #endif
 179
 180 struct dl_phdr_info
 181   {
 182 #ifdef __FDPIC__
 183     struct elf32_fdpic_loadaddr dlpi_addr;
 184 #else
 185 #ifdef __DSBT__
 186     struct elf32_dsbt_loadaddr dlpi_addr;
 187 #else
 188     ElfW(Addr) dlpi_addr;
 189 #endif
 190 #endif
 191     const char *dlpi_name;
 192     const ElfW(Phdr) *dlpi_phdr;
 193     ElfW(Half) dlpi_phnum;
 194
 195 #if 0
 196     /* Note: Following members were introduced after the first
 197        version of this structure was available.  Check the SIZE
 198        argument passed to the dl_iterate_phdr callback to determine
 199        whether or not each later member is available.  */
 200
 201     /* Incremented when a new object may have been added.  */
 202     unsigned long long int dlpi_adds;
 203     /* Incremented when an object may have been removed.  */
 204     unsigned long long int dlpi_subs;
 205
 206     /* If there is a PT_TLS segment, its module ID as used in
 207        TLS relocations, else zero.  */
 208     size_t dlpi_tls_modid;
 209
 210     /* The address of the calling thread's instance of this module's
 211        PT_TLS segment, if it has one and it has been allocated
 212        in the calling thread, otherwise a null pointer.  */
 213     void *dlpi_tls_data;
 214 #endif
 215   };
 216
 217 __BEGIN_DECLS
 218
 219 extern int dl_iterate_phdr (int (*__callback) (struct dl_phdr_info *,
 220                                                size_t, void *),
 221                             void *__data);
 222
 223
 224 #if 0
 225 /* Prototypes for the ld.so auditing interfaces.  These are not
 226    defined anywhere in ld.so but instead have to be provided by the
 227    auditing DSO.  */
 228 extern unsigned int la_version (unsigned int __version);
 229 extern void la_activity (uintptr_t *__cookie, unsigned int __flag);
 230 extern char *la_objsearch (const char *__name, uintptr_t *__cookie,
 231                            unsigned int __flag);
 232 extern unsigned int la_objopen (struct link_map *__map, Lmid_t __lmid,
 233                                 uintptr_t *__cookie);
 234 extern void la_preinit (uintptr_t *__cookie);
 235 extern uintptr_t la_symbind32 (Elf32_Sym *__sym, unsigned int __ndx,
 236                                uintptr_t *__refcook, uintptr_t *__defcook,
 237                                unsigned int *__flags, const char *__symname);
 238 extern uintptr_t la_symbind64 (Elf64_Sym *__sym, unsigned int __ndx,
 239                                uintptr_t *__refcook, uintptr_t *__defcook,
 240                                unsigned int *__flags, const char *__symname);
 241 extern unsigned int la_objclose (uintptr_t *__cookie);
 242 #endif
 243
 244 __END_DECLS
 245
 246 #endif
 247
 248 #endif /* link.h */