dl-defs.h 8.3 KB

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