ldso/include/dl-defs.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 _DL_DEFS_H
   9 #define _DL_DEFS_H
  10
  11 #define FLAG_ANY             -1
  12 #define FLAG_TYPE_MASK       0x00ff
  13 #define FLAG_LIBC4           0x0000
  14 #define FLAG_ELF             0x0001
  15 #define FLAG_ELF_LIBC5       0x0002
  16 #define FLAG_ELF_LIBC6       0x0003
  17 #define FLAG_ELF_UCLIBC      0x0004
  18 #define FLAG_REQUIRED_MASK   0xff00
  19 #define FLAG_SPARC_LIB64     0x0100
  20 #define FLAG_IA64_LIB64      0x0200
  21 #define FLAG_X8664_LIB64     0x0300
  22 #define FLAG_S390_LIB64      0x0400
  23 #define FLAG_POWERPC_LIB64   0x0500
  24 #define FLAG_MIPS64_LIBN32   0x0600
  25 #define FLAG_MIPS64_LIBN64   0x0700
  26
  27 #define LIB_ANY      -1
  28 #define LIB_DLL       0
  29 #define LIB_ELF       1
  30 #define LIB_ELF64     0x80
  31 #define LIB_ELF_LIBC5 2
  32 #define LIB_ELF_LIBC6 3
  33 #define LIB_ELF_LIBC0 4
  34
  35 #if defined(__LDSO_PRELOAD_FILE_SUPPORT__) || defined(__LDSO_CACHE_SUPPORT__)
  36 #ifndef __LDSO_BASE_FILENAME__
  37 #define __LDSO_BASE_FILENAME__ "ld.so"
  38 #endif
  39 #define LDSO_BASE_PATH UCLIBC_RUNTIME_PREFIX "etc/" __LDSO_BASE_FILENAME__
  40
  41 #ifdef __LDSO_PRELOAD_FILE_SUPPORT__
  42 #define LDSO_PRELOAD LDSO_BASE_PATH ".preload"
  43 #endif
  44
  45 #ifdef __LDSO_CACHE_SUPPORT__
  46 #define LDSO_CONF    LDSO_BASE_PATH ".conf"
  47 #define LDSO_CACHE   LDSO_BASE_PATH ".cache"
  48
  49 #define LDSO_CACHE_MAGIC "ld.so-"
  50 #define LDSO_CACHE_MAGIC_LEN (sizeof LDSO_CACHE_MAGIC -1)
  51 #define LDSO_CACHE_VER "1.7.0"
  52 #define LDSO_CACHE_VER_LEN (sizeof LDSO_CACHE_VER -1)
  53
  54 typedef struct {
  55         char magic   [LDSO_CACHE_MAGIC_LEN];
  56         char version [LDSO_CACHE_VER_LEN];
  57         int nlibs;
  58 } header_t;
  59
  60 typedef struct {
  61         int flags;
  62         int sooffset;
  63         int liboffset;
  64 } libentry_t;
  65
  66 #ifdef __ARCH_USE_MMU__
  67 #define LDSO_CACHE_MMAP_FLAGS (MAP_SHARED)
  68 #else
  69 #define LDSO_CACHE_MMAP_FLAGS (MAP_PRIVATE)
  70 #endif
  71 #endif  /* __LDSO_CACHE_SUPPORT__ */
  72
  73 #endif
  74
  75 #ifdef _LIBC
  76 #ifndef __ARCH_HAS_NO_SHARED__
  77 /* arch specific defines */
  78 #include <dl-sysdep.h>
  79 #endif
  80 #endif
  81
  82 /* Provide a means for a port to pass additional arguments to the _dl_start
  83    function.  */
  84 #ifndef DL_START
  85 # define DL_START(X) static void * __attribute_used__ _dl_start(X)
  86 #endif
  87
  88 /* Machines in which different sections may be relocated by different
  89  * amounts should define this and LD_RELOC_ADDR.  If you change this,
  90  * make sure you change struct link_map in include/link.h accordingly
  91  * such that it matches a prefix of struct elf_resolve.
  92  */
  93 #ifndef DL_LOADADDR_TYPE
  94 # define DL_LOADADDR_TYPE ElfW(Addr)
  95 #endif
  96
  97 /* When DL_LOADADDR_TYPE is not a scalar value, or some different
  98  * computation is needed to relocate an address, define this.
  99  */
 100 #ifndef DL_RELOC_ADDR
 101 # define DL_RELOC_ADDR(LOADADDR, ADDR) \
 102         ((LOADADDR) + (ADDR))
 103 #endif
 104
 105 /* Initialize the location of the dynamic addr.  This is only called
 106  * from DL_START, so additional arguments passed to it may be referenced.  */
 107 #ifndef DL_BOOT_COMPUTE_DYN
 108 #define DL_BOOT_COMPUTE_DYN(DPNT, GOT, LOAD_ADDR) \
 109     ((DPNT) = ((ElfW(Dyn) *) DL_RELOC_ADDR(LOAD_ADDR, GOT)))
 110 #endif
 111
 112 /* Initialize the location of the global offset table.  This is only called
 113  * from DL_START, so additional arguments passed to it may be referenced.  */
 114 #ifndef DL_BOOT_COMPUTE_GOT
 115 #define DL_BOOT_COMPUTE_GOT(GOT) \
 116     ((GOT) = elf_machine_dynamic())
 117 #endif
 118
 119 /* Initialize a LOADADDR representing the loader itself.  It's only
 120  * called from DL_START, so additional arguments passed to it may be
 121  * referenced.
 122  */
 123 #ifndef DL_INIT_LOADADDR_BOOT
 124 # define DL_INIT_LOADADDR_BOOT(LOADADDR, BASEADDR) \
 125         ((LOADADDR) = (BASEADDR))
 126 #endif
 127
 128 /* Define if any declarations/definitions of local variables are
 129  * needed in a function that calls DT_INIT_LOADADDR or
 130  * DL_INIT_LOADADDR_HDR.  Declarations must be properly terminated
 131  * with a semicolon, and non-declaration statements are forbidden.
 132  */
 133 #ifndef DL_INIT_LOADADDR_EXTRA_DECLS
 134 # define DL_INIT_LOADADDR_EXTRA_DECLS /* int i; */
 135 #endif
 136
 137 /* Prepare a DL_LOADADDR_TYPE data structure for incremental
 138  * initialization with DL_INIT_LOADADDR_HDR, given pointers to a base
 139  * load address and to program headers.
 140  */
 141 #ifndef DL_INIT_LOADADDR
 142 # define DL_INIT_LOADADDR(LOADADDR, BASEADDR, PHDR, PHDRCNT) \
 143         ((LOADADDR) = (BASEADDR))
 144 #endif
 145
 146 /* Initialize a LOADADDR representing the program.  It's called from
 147  * DL_BOOT only.
 148  */
 149 #ifndef DL_INIT_LOADADDR_PROG
 150 # define DL_INIT_LOADADDR_PROG(LOADADDR, BASEADDR) \
 151         ((LOADADDR) = (DL_LOADADDR_TYPE)(BASEADDR))
 152 #endif
 153
 154 /* Update LOADADDR with information about PHDR, just mapped to the
 155    given ADDR.  */
 156 #ifndef DL_INIT_LOADADDR_HDR
 157 # define DL_INIT_LOADADDR_HDR(LOADADDR, ADDR, PHDR) /* Do nothing.  */
 158 #endif
 159
 160 /* Convert a DL_LOADADDR_TYPE to an identifying pointer.  Used mostly
 161  * for debugging.
 162  */
 163 #ifndef DL_LOADADDR_BASE
 164 # define DL_LOADADDR_BASE(LOADADDR) (LOADADDR)
 165 #endif
 166
 167 /* Test whether a given ADDR is more likely to be within the memory
 168  * region mapped to TPNT (a struct elf_resolve *) than to TFROM.
 169  * Everywhere that this is used, TFROM is initially NULL, and whenever
 170  * a potential match is found, it's updated.  One might want to walk
 171  * the chain of elf_resolve to locate the best match and return false
 172  * whenever TFROM is non-NULL, or use an exact-matching algorithm
 173  * using additional information encoded in DL_LOADADDR_TYPE to test
 174  * for exact containment.
 175  */
 176 #ifndef DL_ADDR_IN_LOADADDR
 177 # define DL_ADDR_IN_LOADADDR(ADDR, TPNT, TFROM) \
 178         ((void*)(TPNT)->mapaddr < (void*)(ADDR) \
 179          && (!(TFROM) || (TFROM)->mapaddr < (TPNT)->mapaddr))
 180 #endif
 181
 182 /* This is called from dladdr() to give targets that use function descriptors
 183  * a chance to map a function descriptor's address to the function's entry
 184  * point before trying to find in which library it's defined.  */
 185 #ifndef DL_LOOKUP_ADDRESS
 186 #define DL_LOOKUP_ADDRESS(ADDRESS) (ADDRESS)
 187 #endif
 188
 189 /* On some architectures dladdr can't use st_size of all symbols this way.  */
 190 #define DL_ADDR_SYM_MATCH(SYM_ADDR, SYM, MATCHSYM, ADDR)                                \
 191   ((ADDR) >= (SYM_ADDR)                                                                                                 \
 192    && ((((SYM)->st_shndx == SHN_UNDEF || (SYM)->st_size == 0)                   \
 193         && (ADDR) == (SYM_ADDR))                                                                                \
 194        || (ADDR) < (SYM_ADDR) + (SYM)->st_size)                                                 \
 195    && (!(MATCHSYM) || MATCHSYM < (SYM_ADDR)))
 196
 197 /* Use this macro to convert a pointer to a function's entry point to
 198  * a pointer to function.  The pointer is assumed to have already been
 199  * relocated.  LOADADDR is passed because it may contain additional
 200  * information needed to compute the pointer to function.
 201  */
 202 #ifndef DL_ADDR_TO_FUNC_PTR
 203 # define DL_ADDR_TO_FUNC_PTR(ADDR, LOADADDR) ((void(*)(void))(ADDR))
 204 #endif
 205
 206 /* On some platforms, computing a pointer to function is more
 207    expensive than calling a function at a given address, so this
 208    alternative is provided.  The function signature must be given
 209    within parentheses, as in a type cast.  */
 210 #ifndef DL_CALL_FUNC_AT_ADDR
 211 # define DL_CALL_FUNC_AT_ADDR(ADDR, LOADADDR, SIGNATURE, ...) \
 212   ((*SIGNATURE DL_ADDR_TO_FUNC_PTR ((ADDR), (LOADADDR)))(__VA_ARGS__))
 213 #endif
 214
 215 /* An alignment value for a memory block returned by _dl_malloc. */
 216 #ifndef DL_MALLOC_ALIGN
 217 # define DL_MALLOC_ALIGN (__WORDSIZE / 8)
 218 #endif
 219
 220 #ifdef __UCLIBC_UNDERSCORES__
 221 # define __C_SYMBOL_PREFIX__ "_"
 222 #else
 223 # define __C_SYMBOL_PREFIX__ ""
 224 #endif
 225
 226 /* Define this if you want to modify the VALUE returned by
 227    _dl_find_hash for this reloc TYPE.  TPNT is the module in which the
 228    matching SYM was found.  */
 229 #ifndef DL_FIND_HASH_VALUE
 230 # define DL_FIND_HASH_VALUE(TPNT, TYPE, SYM) (DL_RELOC_ADDR ((TPNT)->loadaddr, (SYM)->st_value))
 231 #endif
 232
 233 /* Unmap all previously-mapped segments accumulated in LOADADDR.
 234    Generally used when an error occurs during loading.  */
 235 #ifndef DL_LOADADDR_UNMAP
 236 # define DL_LOADADDR_UNMAP(LOADADDR, LEN) \
 237   _dl_munmap((char *) (LOADADDR), (LEN))
 238 #endif
 239
 240 /* Similar to DL_LOADADDR_UNMAP, but used for libraries that have been
 241    dlopen()ed successfully, when they're dlclose()d.  */
 242 #ifndef DL_LIB_UNMAP
 243 # define DL_LIB_UNMAP(LIB, LEN) (DL_LOADADDR_UNMAP ((LIB)->mapaddr, (LEN)))
 244 #endif
 245
 246 /* Define this to verify that a library named LIBNAME, whose ELF
 247    headers are pointed to by EPNT, is suitable for dynamic linking.
 248    If it is not, print an error message (optional) and return NULL.
 249    If the library can have its segments relocated independently,
 250    arrange for PICLIB to be set to 2.  If all segments have to be
 251    relocated by the same amount, set it to 1.  If it has to be loaded
 252    at physical addresses as specified in the program headers, set it
 253    to 0.  A reasonable (?) guess for PICLIB will already be in place,
 254    so it is safe to do nothing here.  */
 255 #ifndef DL_CHECK_LIB_TYPE
 256 # define DL_CHECK_LIB_TYPE(EPNT, PICLIB, PROGNAME, LIBNAME) (void)0
 257 #endif
 258
 259 /* Define this if you have special segment.  */
 260 #ifndef DL_IS_SPECIAL_SEGMENT
 261 # define DL_IS_SPECIAL_SEGMENT(EPNT, PPNT) 0
 262 #endif
 263
 264 /* Define this if you want to use special method to map the segment.  */
 265 #ifndef DL_MAP_SEGMENT
 266 # define DL_MAP_SEGMENT(EPNT, PPNT, INFILE, FLAGS) 0
 267 #endif
 268
 269 /* Define this to declare the library offset. */
 270 #ifndef DL_DEF_LIB_OFFSET
 271 # define DL_DEF_LIB_OFFSET static unsigned long _dl_library_offset
 272 #endif
 273
 274 /* Define this to get the library offset. */
 275 #ifndef DL_GET_LIB_OFFSET
 276 # define DL_GET_LIB_OFFSET() _dl_library_offset
 277 #endif
 278
 279 /* Define this to set the library offset  as difference beetwen the mapped
 280    library address and the smallest virtual address of the first PT_LOAD
 281    segment. */
 282 #ifndef DL_SET_LIB_OFFSET
 283 # define DL_SET_LIB_OFFSET(offset) (_dl_library_offset = (offset))
 284 #endif
 285
 286 /* Define this to get the real object's runtime address. */
 287 #ifndef DL_GET_RUN_ADDR
 288 # define DL_GET_RUN_ADDR(loadaddr, mapaddr) (mapaddr)
 289 #endif
 290
 291 #endif  /* _DL_DEFS_H */