ldso/include/dl-defs.h

   1 /*
   2  * Copyright (C) 2000-2006 by Erik Andersen <andersen@codepoet.org>
   3  *
   4  * GNU Lesser General Public License version 2.1 or later.
   5  */
   6
   7 #ifndef _DL_DEFS_H
   8 #define _DL_DEFS_H
   9
  10 #define FLAG_ANY             -1
  11 #define FLAG_TYPE_MASK       0x00ff
  12 #define FLAG_LIBC4           0x0000
  13 #define FLAG_ELF             0x0001
  14 #define FLAG_ELF_LIBC5       0x0002
  15 #define FLAG_ELF_LIBC6       0x0003
  16 #define FLAG_ELF_UCLIBC      0x0004
  17 #define FLAG_REQUIRED_MASK   0xff00
  18 #define FLAG_SPARC_LIB64     0x0100
  19 #define FLAG_IA64_LIB64      0x0200
  20 #define FLAG_X8664_LIB64     0x0300
  21 #define FLAG_S390_LIB64      0x0400
  22 #define FLAG_POWERPC_LIB64   0x0500
  23 #define FLAG_MIPS64_LIBN32   0x0600
  24 #define FLAG_MIPS64_LIBN64   0x0700
  25
  26 #define LIB_ANY      -1
  27 #define LIB_DLL       0
  28 #define LIB_ELF       1
  29 #define LIB_ELF64     0x80
  30 #define LIB_ELF_LIBC5 2
  31 #define LIB_ELF_LIBC6 3
  32 #define LIB_ELF_LIBC0 4
  33
  34 #if defined(__LDSO_PRELOAD_FILE_SUPPORT__) || defined(__LDSO_CACHE_SUPPORT__)
  35 #ifndef __LDSO_BASE_FILENAME__
  36 #define __LDSO_BASE_FILENAME__ "ld.so"
  37 #endif
  38 #define LDSO_BASE_PATH UCLIBC_RUNTIME_PREFIX "etc/" __LDSO_BASE_FILENAME__
  39
  40 #ifdef __LDSO_PRELOAD_FILE_SUPPORT__
  41 #define LDSO_PRELOAD LDSO_BASE_PATH ".preload"
  42 #endif
  43
  44 #ifdef __LDSO_CACHE_SUPPORT__
  45 #define LDSO_CONF    LDSO_BASE_PATH ".conf"
  46 #define LDSO_CACHE   LDSO_BASE_PATH ".cache"
  47
  48 #define LDSO_CACHE_MAGIC "ld.so-"
  49 #define LDSO_CACHE_MAGIC_LEN (sizeof LDSO_CACHE_MAGIC -1)
  50 #define LDSO_CACHE_VER "1.7.0"
  51 #define LDSO_CACHE_VER_LEN (sizeof LDSO_CACHE_VER -1)
  52
  53 typedef struct {
  54         char magic   [LDSO_CACHE_MAGIC_LEN];
  55         char version [LDSO_CACHE_VER_LEN];
  56         int nlibs;
  57 } header_t;
  58
  59 typedef struct {
  60         int flags;
  61         int sooffset;
  62         int liboffset;
  63 } libentry_t;
  64
  65 #ifdef __ARCH_USE_MMU__
  66 #define LDSO_CACHE_MMAP_FLAGS (MAP_SHARED)
  67 #else
  68 #define LDSO_CACHE_MMAP_FLAGS (MAP_PRIVATE)
  69 #endif
  70 #endif  /* __LDSO_CACHE_SUPPORT__ */
  71
  72 #endif
  73
  74 #ifdef _LIBC
  75 #ifndef __ARCH_HAS_NO_LDSO__
  76 /* arch specific defines */
  77 #include <dl-sysdep.h>
  78 #endif
  79 #ifdef __TARGET_c6x__
  80 #include <dl-sysdep.h>
  81 #endif
  82 #endif
  83
  84 /* Provide a means for a port to pass additional arguments to the _dl_start
  85    function.  */
  86 #ifndef DL_START
  87 # define DL_START(X) static void * __attribute_used__ _dl_start(X)
  88 #endif
  89
  90 /* Machines in which different sections may be relocated by different
  91  * amounts should define this and LD_RELOC_ADDR.  If you change this,
  92  * make sure you change struct link_map in include/link.h accordingly
  93  * such that it matches a prefix of struct elf_resolve.
  94  */
  95 #ifndef DL_LOADADDR_TYPE
  96 # define DL_LOADADDR_TYPE ElfW(Addr)
  97 #endif
  98
  99 /* When DL_LOADADDR_TYPE is not a scalar value, or some different
 100  * computation is needed to relocate an address, define this.
 101  */
 102 #ifndef DL_RELOC_ADDR
 103 # define DL_RELOC_ADDR(LOADADDR, ADDR) \
 104         ((LOADADDR) + (ADDR))
 105 #endif
 106
 107 /* Initialize the location of the dynamic addr.  This is only called
 108  * from DL_START, so additional arguments passed to it may be referenced.  */
 109 #ifndef DL_BOOT_COMPUTE_DYN
 110 #define DL_BOOT_COMPUTE_DYN(DPNT, GOT, LOAD_ADDR) \
 111     ((DPNT) = ((ElfW(Dyn) *) DL_RELOC_ADDR(LOAD_ADDR, GOT)))
 112 #endif
 113
 114 /* Initialize the location of the global offset table.  This is only called
 115  * from DL_START, so additional arguments passed to it may be referenced.  */
 116 #ifndef DL_BOOT_COMPUTE_GOT
 117 #define DL_BOOT_COMPUTE_GOT(GOT) \
 118     ((GOT) = elf_machine_dynamic())
 119 #endif
 120
 121 /* Initialize a LOADADDR representing the loader itself.  It's only
 122  * called from DL_START, so additional arguments passed to it may be
 123  * referenced.
 124  */
 125 #ifndef DL_INIT_LOADADDR_BOOT
 126 # define DL_INIT_LOADADDR_BOOT(LOADADDR, BASEADDR) \
 127         ((LOADADDR) = (BASEADDR))
 128 #endif
 129
 130 /* Define if any declarations/definitions of local variables are
 131  * needed in a function that calls DT_INIT_LOADADDR or
 132  * DL_INIT_LOADADDR_HDR.  Declarations must be properly terminated
 133  * with a semicolon, and non-declaration statements are forbidden.
 134  */
 135 #ifndef DL_INIT_LOADADDR_EXTRA_DECLS
 136 # define DL_INIT_LOADADDR_EXTRA_DECLS /* int i; */
 137 #endif
 138
 139 /* Prepare a DL_LOADADDR_TYPE data structure for incremental
 140  * initialization with DL_INIT_LOADADDR_HDR, given pointers to a base
 141  * load address and to program headers.
 142  */
 143 #ifndef DL_INIT_LOADADDR
 144 # define DL_INIT_LOADADDR(LOADADDR, BASEADDR, PHDR, PHDRCNT) \
 145         ((LOADADDR) = (BASEADDR))
 146 #endif
 147
 148 /* Initialize a LOADADDR representing the program.  It's called from
 149  * DL_BOOT only.
 150  */
 151 #ifndef DL_INIT_LOADADDR_PROG
 152 # define DL_INIT_LOADADDR_PROG(LOADADDR, BASEADDR) \
 153         ((LOADADDR) = (DL_LOADADDR_TYPE)(BASEADDR))
 154 #endif
 155
 156 /* Update LOADADDR with information about PHDR, just mapped to the
 157    given ADDR.  */
 158 #ifndef DL_INIT_LOADADDR_HDR
 159 # define DL_INIT_LOADADDR_HDR(LOADADDR, ADDR, PHDR) /* Do nothing.  */
 160 #endif
 161
 162 /* Convert a DL_LOADADDR_TYPE to an identifying pointer.  Used mostly
 163  * for debugging.
 164  */
 165 #ifndef DL_LOADADDR_BASE
 166 # define DL_LOADADDR_BASE(LOADADDR) (LOADADDR)
 167 #endif
 168
 169 /* Test whether a given ADDR is more likely to be within the memory
 170  * region mapped to TPNT (a struct elf_resolve *) than to TFROM.
 171  * Everywhere that this is used, TFROM is initially NULL, and whenever
 172  * a potential match is found, it's updated.  One might want to walk
 173  * the chain of elf_resolve to locate the best match and return false
 174  * whenever TFROM is non-NULL, or use an exact-matching algorithm
 175  * using additional information encoded in DL_LOADADDR_TYPE to test
 176  * for exact containment.
 177  */
 178 #ifndef DL_ADDR_IN_LOADADDR
 179 # define DL_ADDR_IN_LOADADDR(ADDR, TPNT, TFROM) \
 180         ((void*)(TPNT)->mapaddr < (void*)(ADDR) \
 181          && (!(TFROM) || (TFROM)->mapaddr < (TPNT)->mapaddr))
 182 #endif
 183
 184 /* This is called from dladdr() to give targets that use function descriptors
 185  * a chance to map a function descriptor's address to the function's entry
 186  * point before trying to find in which library it's defined.  */
 187 #ifndef DL_LOOKUP_ADDRESS
 188 #define DL_LOOKUP_ADDRESS(ADDRESS) (ADDRESS)
 189 #endif
 190
 191 /* On some architectures dladdr can't use st_size of all symbols this way.  */
 192 #define DL_ADDR_SYM_MATCH(SYM_ADDR, SYM, MATCHSYM, ADDR)                                \
 193   ((ADDR) >= (SYM_ADDR)                                                                                                 \
 194    && ((((SYM)->st_shndx == SHN_UNDEF || (SYM)->st_size == 0)                   \
 195         && (ADDR) == (SYM_ADDR))                                                                                \
 196        || (ADDR) < (SYM_ADDR) + (SYM)->st_size)                                                 \
 197    && (!(MATCHSYM) || MATCHSYM < (SYM_ADDR)))
 198
 199 /* Use this macro to convert a pointer to a function's entry point to
 200  * a pointer to function.  The pointer is assumed to have already been
 201  * relocated.  LOADADDR is passed because it may contain additional
 202  * information needed to compute the pointer to function.
 203  */
 204 #ifndef DL_ADDR_TO_FUNC_PTR
 205 # define DL_ADDR_TO_FUNC_PTR(ADDR, LOADADDR) ((void(*)(void))(ADDR))
 206 #endif
 207
 208 /* On some platforms, computing a pointer to function is more
 209    expensive than calling a function at a given address, so this
 210    alternative is provided.  The function signature must be given
 211    within parentheses, as in a type cast.  */
 212 #ifndef DL_CALL_FUNC_AT_ADDR
 213 # define DL_CALL_FUNC_AT_ADDR(ADDR, LOADADDR, SIGNATURE, ...) \
 214   ((*SIGNATURE DL_ADDR_TO_FUNC_PTR ((ADDR), (LOADADDR)))(__VA_ARGS__))
 215 #endif
 216
 217 /* An alignment value for a memory block returned by _dl_malloc. */
 218 #ifndef DL_MALLOC_ALIGN
 219 # define DL_MALLOC_ALIGN (__WORDSIZE / 8)
 220 #endif
 221
 222 #ifdef __UCLIBC_UNDERSCORES__
 223 # define __C_SYMBOL_PREFIX__ "_"
 224 #else
 225 # define __C_SYMBOL_PREFIX__ ""
 226 #endif
 227
 228 /* Define this if you want to modify the VALUE returned by
 229    _dl_find_hash for this reloc TYPE.  TPNT is the module in which the
 230    matching SYM was found.  */
 231 #ifndef DL_FIND_HASH_VALUE
 232 # define DL_FIND_HASH_VALUE(TPNT, TYPE, SYM) (DL_RELOC_ADDR ((TPNT)->loadaddr, (SYM)->st_value))
 233 #endif
 234
 235 /* Unmap all previously-mapped segments accumulated in LOADADDR.
 236    Generally used when an error occurs during loading.  */
 237 #ifndef DL_LOADADDR_UNMAP
 238 # define DL_LOADADDR_UNMAP(LOADADDR, LEN) \
 239   _dl_munmap((char *) (LOADADDR), (LEN))
 240 #endif
 241
 242 /* Similar to DL_LOADADDR_UNMAP, but used for libraries that have been
 243    dlopen()ed successfully, when they're dlclose()d.  */
 244 #ifndef DL_LIB_UNMAP
 245 # define DL_LIB_UNMAP(LIB, LEN) (DL_LOADADDR_UNMAP ((LIB)->mapaddr, (LEN)))
 246 #endif
 247
 248 /* Define this to verify that a library named LIBNAME, whose ELF
 249    headers are pointed to by EPNT, is suitable for dynamic linking.
 250    If it is not, print an error message (optional) and return NULL.
 251    If the library can have its segments relocated independently,
 252    arrange for PICLIB to be set to 2.  If all segments have to be
 253    relocated by the same amount, set it to 1.  If it has to be loaded
 254    at physical addresses as specified in the program headers, set it
 255    to 0.  A reasonable (?) guess for PICLIB will already be in place,
 256    so it is safe to do nothing here.  */
 257 #ifndef DL_CHECK_LIB_TYPE
 258 # define DL_CHECK_LIB_TYPE(EPNT, PICLIB, PROGNAME, LIBNAME) (void)0
 259 #endif
 260
 261 /* Define this if you have special segment.  */
 262 #ifndef DL_IS_SPECIAL_SEGMENT
 263 # define DL_IS_SPECIAL_SEGMENT(EPNT, PPNT) 0
 264 #endif
 265
 266 /* Define this if you want to use special method to map the segment.  */
 267 #ifndef DL_MAP_SEGMENT
 268 # define DL_MAP_SEGMENT(EPNT, PPNT, INFILE, FLAGS) 0
 269 #endif
 270
 271 /* Define this to declare the library offset. */
 272 #ifndef DL_DEF_LIB_OFFSET
 273 # define DL_DEF_LIB_OFFSET static unsigned long _dl_library_offset
 274 #endif
 275
 276 /* Define this to get the library offset. */
 277 #ifndef DL_GET_LIB_OFFSET
 278 # define DL_GET_LIB_OFFSET() _dl_library_offset
 279 #endif
 280
 281 /* Define this to set the library offset  as difference beetwen the mapped
 282    library address and the smallest virtual address of the first PT_LOAD
 283    segment. */
 284 #ifndef DL_SET_LIB_OFFSET
 285 # define DL_SET_LIB_OFFSET(offset) (_dl_library_offset = (offset))
 286 #endif
 287
 288 /* Define this to get the real object's runtime address. */
 289 #ifndef DL_GET_RUN_ADDR
 290 # define DL_GET_RUN_ADDR(loadaddr, mapaddr) (mapaddr)
 291 #endif
 292
 293 #endif  /* _DL_DEFS_H */