ldso/include/dl-hash.h

   1 /* vi: set sw=4 ts=4: */
   2 /*
   3  * Copyright (C) 2000-2006 by Erik Andersen <andersen@codepoet.org>
   4  *
   5  * GNU Lesser General Public License version 2.1 or later.
   6  */
   7
   8 #ifndef _LD_HASH_H_
   9 #define _LD_HASH_H_
  10
  11 #ifndef RTLD_NEXT
  12 #define RTLD_NEXT       ((void*)-1)
  13 #endif
  14
  15 struct init_fini {
  16         struct elf_resolve **init_fini;
  17         unsigned long nlist; /* Number of entries in init_fini */
  18 };
  19
  20 struct dyn_elf {
  21   struct elf_resolve * dyn;
  22   struct dyn_elf * next_handle;  /* Used by dlopen et al. */
  23   struct init_fini init_fini;
  24   struct dyn_elf * next;
  25   struct dyn_elf * prev;
  26 };
  27
  28 struct symbol_ref {
  29   const ElfW(Sym) *sym;
  30   struct elf_resolve *tpnt;
  31 };
  32
  33 struct elf_resolve {
  34   /* These entries must be in this order to be compatible with the interface used
  35      by gdb to obtain the list of symbols. */
  36   DL_LOADADDR_TYPE loadaddr;    /* Base address shared object is loaded at.  */
  37   char *libname;                /* Absolute file name object was found in.  */
  38   ElfW(Dyn) *dynamic_addr;      /* Dynamic section of the shared object.  */
  39   struct elf_resolve * next;
  40   struct elf_resolve * prev;
  41   /* Nothing after this address is used by gdb. */
  42
  43 #if defined(USE_TLS) && USE_TLS
  44   /* Thread-local storage related info.  */
  45
  46   /* Start of the initialization image.  */
  47   void *l_tls_initimage;
  48   /* Size of the initialization image.  */
  49   size_t l_tls_initimage_size;
  50   /* Size of the TLS block.  */
  51   size_t l_tls_blocksize;
  52   /* Alignment requirement of the TLS block.  */
  53   size_t l_tls_align;
  54   /* Offset of first byte module alignment.  */
  55   size_t l_tls_firstbyte_offset;
  56 # ifndef NO_TLS_OFFSET
  57 #  define NO_TLS_OFFSET 0
  58 # endif
  59   /* For objects present at startup time: offset in the static TLS block.  */
  60   ptrdiff_t l_tls_offset;
  61   /* Index of the module in the dtv array.  */
  62   size_t l_tls_modid;
  63   /* Nonzero if _dl_init_static_tls should be called for this module */
  64   unsigned int l_need_tls_init:1;
  65 #endif
  66
  67   ElfW(Addr) mapaddr;
  68   enum {elf_lib, elf_executable,program_interpreter, loaded_file} libtype;
  69   struct dyn_elf * symbol_scope;
  70   unsigned short usage_count;
  71   unsigned short int init_flag;
  72   unsigned long rtld_flags; /* RTLD_GLOBAL, RTLD_NOW etc. */
  73   Elf_Symndx nbucket;
  74
  75 #ifdef __LDSO_GNU_HASH_SUPPORT__
  76   /* Data needed to support GNU hash style */
  77   Elf32_Word l_gnu_bitmask_idxbits;
  78   Elf32_Word l_gnu_shift;
  79   const ElfW(Addr) *l_gnu_bitmask;
  80
  81   union
  82   {
  83     const Elf32_Word *l_gnu_chain_zero;
  84     const Elf_Symndx *elf_buckets;
  85   };
  86 #else
  87   Elf_Symndx *elf_buckets;
  88 #endif
  89
  90   struct init_fini_list *init_fini;
  91   struct init_fini_list *rtld_local; /* keep tack of RTLD_LOCAL libs in same group */
  92   /*
  93    * These are only used with ELF style shared libraries
  94    */
  95   Elf_Symndx nchain;
  96
  97 #ifdef __LDSO_GNU_HASH_SUPPORT__
  98   union
  99   {
 100     const Elf32_Word *l_gnu_buckets;
 101     const Elf_Symndx *chains;
 102   };
 103 #else
 104   Elf_Symndx *chains;
 105 #endif
 106   unsigned long dynamic_info[DYNAMIC_SIZE];
 107
 108   unsigned long n_phent;
 109   ElfW(Phdr) * ppnt;
 110
 111   ElfW(Addr) relro_addr;
 112   size_t relro_size;
 113
 114   dev_t st_dev;      /* device */
 115   ino_t st_ino;      /* inode */
 116
 117 #ifdef __powerpc__
 118   /* this is used to store the address of relocation data words, so
 119    * we don't have to calculate it every time, which requires a divide */
 120   unsigned long data_words;
 121 #endif
 122
 123 #ifdef __FDPIC__
 124   /* Every loaded module holds a hashtable of function descriptors of
 125      functions defined in it, such that it's easy to release the
 126      memory when the module is dlclose()d.  */
 127   struct funcdesc_ht *funcdesc_ht;
 128 #endif
 129 };
 130
 131 #define RELOCS_DONE         0x000001
 132 #define JMP_RELOCS_DONE     0x000002
 133 #define INIT_FUNCS_CALLED   0x000004
 134 #define FINI_FUNCS_CALLED   0x000008
 135 #define DL_OPENED           0x000010
 136
 137 extern struct dyn_elf     * _dl_symbol_tables;
 138 extern struct elf_resolve * _dl_loaded_modules;
 139 extern struct dyn_elf     * _dl_handles;
 140
 141 extern struct elf_resolve * _dl_add_elf_hash_table(const char * libname,
 142         DL_LOADADDR_TYPE loadaddr, unsigned long * dynamic_info,
 143         unsigned long dynamic_addr, unsigned long dynamic_size);
 144
 145 extern char *_dl_lookup_hash(const char *name, struct dyn_elf *rpnt,
 146                 struct elf_resolve *mytpnt, int type_class,
 147                 struct symbol_ref *symbol);
 148 static __always_inline char *_dl_find_hash(const char *name, struct dyn_elf *rpnt,
 149                 struct elf_resolve *mytpnt, int type_class,
 150                 struct symbol_ref *symbol)
 151 {
 152         return _dl_lookup_hash(name, rpnt, mytpnt, type_class, symbol);
 153 }
 154
 155 extern int _dl_linux_dynamic_link(void);
 156
 157 extern char * _dl_library_path;
 158 extern char * _dl_not_lazy;
 159
 160 static __inline__ int _dl_symbol(char * name)
 161 {
 162   if (name[0] != '_' || name[1] != 'd' || name[2] != 'l' || name[3] != '_')
 163     return 0;
 164   return 1;
 165 }
 166
 167 #define LD_ERROR_NOFILE 1
 168 #define LD_ERROR_NOZERO 2
 169 #define LD_ERROR_NOTELF 3
 170 #define LD_ERROR_NOTMAGIC 4
 171 #define LD_ERROR_NOTDYN 5
 172 #define LD_ERROR_MMAP_FAILED 6
 173 #define LD_ERROR_NODYNAMIC 7
 174 #define LD_ERROR_TLS_FAILED 8
 175 #define LD_WRONG_RELOCS 9
 176 #define LD_BAD_HANDLE 10
 177 #define LD_NO_SYMBOL 11
 178
 179 #endif /* _LD_HASH_H_ */