uclibc-ng/ldso/include/dl-defs.h

/* vi: set sw=4 ts=4: */
/*
 * Copyright (C) 2000-2006 by Erik Andersen <andersen@codepoet.org>
 *
 * GNU Lesser General Public License version 2.1 or later.
 */

#ifndef _LD_DEFS_H
#define _LD_DEFS_H

#define FLAG_ANY             -1
#define FLAG_TYPE_MASK       0x00ff
#define FLAG_LIBC4           0x0000
#define FLAG_ELF             0x0001
#define FLAG_ELF_LIBC5       0x0002
#define FLAG_ELF_LIBC6       0x0003
#define FLAG_ELF_UCLIBC      0x0004
#define FLAG_REQUIRED_MASK   0xff00
#define FLAG_SPARC_LIB64     0x0100
#define FLAG_IA64_LIB64      0x0200
#define FLAG_X8664_LIB64     0x0300
#define FLAG_S390_LIB64      0x0400
#define FLAG_POWERPC_LIB64   0x0500
#define FLAG_MIPS64_LIBN32   0x0600
#define FLAG_MIPS64_LIBN64   0x0700

#define LIB_ANY	     -1
#define LIB_DLL       0
#define LIB_ELF       1
#define LIB_ELF64     0x80
#define LIB_ELF_LIBC5 2
#define LIB_ELF_LIBC6 3
#define LIB_ELF_LIBC0 4

#if defined(__LDSO_PRELOAD_FILE_SUPPORT__) || defined(__LDSO_CACHE_SUPPORT__)
#ifndef __LDSO_BASE_FILENAME__
#define __LDSO_BASE_FILENAME__ "ld.so"
#endif
#define LDSO_BASE_PATH UCLIBC_RUNTIME_PREFIX "etc/" __LDSO_BASE_FILENAME__

#ifdef __LDSO_PRELOAD_FILE_SUPPORT__
#define LDSO_PRELOAD LDSO_BASE_PATH ".preload"
#endif

#ifdef __LDSO_CACHE_SUPPORT__
#define LDSO_CONF    LDSO_BASE_PATH ".conf"
#define LDSO_CACHE   LDSO_BASE_PATH ".cache"

#define LDSO_CACHE_MAGIC "ld.so-"
#define LDSO_CACHE_MAGIC_LEN (sizeof LDSO_CACHE_MAGIC -1)
#define LDSO_CACHE_VER "1.7.0"
#define LDSO_CACHE_VER_LEN (sizeof LDSO_CACHE_VER -1)

typedef struct {
	char magic   [LDSO_CACHE_MAGIC_LEN];
	char version [LDSO_CACHE_VER_LEN];
	int nlibs;
} header_t;

typedef struct {
	int flags;
	int sooffset;
	int liboffset;
} libentry_t;

#ifdef __ARCH_USE_MMU__
#define LDSO_CACHE_MMAP_FLAGS (MAP_SHARED)
#else
#define LDSO_CACHE_MMAP_FLAGS (MAP_PRIVATE)
#endif
#endif	/* __LDSO_CACHE_SUPPORT__ */

#endif

/* Provide a means for a port to pass additional arguments to the _dl_start
   function.  */
#ifndef DL_START
# define DL_START(X) static void * __attribute_used__ _dl_start(X)
#endif

/* Machines in which different sections may be relocated by different
 * amounts should define this and LD_RELOC_ADDR.  If you change this,
 * make sure you change struct link_map in include/link.h accordingly
 * such that it matches a prefix of struct elf_resolve.
 */
#ifndef DL_LOADADDR_TYPE
# define DL_LOADADDR_TYPE ElfW(Addr)
#endif

/* When DL_LOADADDR_TYPE is not a scalar value, or some different
 * computation is needed to relocate an address, define this.
 */
#ifndef DL_RELOC_ADDR
# define DL_RELOC_ADDR(LOADADDR, ADDR) \
	((LOADADDR) + (ADDR))
#endif

/* Initialize the location of the dynamic addr.  This is only called
 * from DL_START, so additional arguments passed to it may be referenced.  */
#ifndef DL_BOOT_COMPUTE_DYN
#define DL_BOOT_COMPUTE_DYN(DPNT, GOT, LOAD_ADDR) \
    ((DPNT) = ((ElfW(Dyn) *) DL_RELOC_ADDR(LOAD_ADDR, GOT)))
#endif

/* Initialize the location of the global offset table.  This is only called
 * from DL_START, so additional arguments passed to it may be referenced.  */
#ifndef DL_BOOT_COMPUTE_GOT
#define DL_BOOT_COMPUTE_GOT(GOT) \
    ((GOT) = elf_machine_dynamic())
#endif

/* Initialize a LOADADDR representing the loader itself.  It's only
 * called from DL_START, so additional arguments passed to it may be
 * referenced.
 */
#ifndef DL_INIT_LOADADDR_BOOT
# define DL_INIT_LOADADDR_BOOT(LOADADDR, BASEADDR) \
	((LOADADDR) = (BASEADDR))
#endif

/* Define if any declarations/definitions of local variables are
 * needed in a function that calls DT_INIT_LOADADDR or
 * DL_INIT_LOADADDR_HDR.  Declarations must be properly terminated
 * with a semicolon, and non-declaration statements are forbidden.
 */
#ifndef DL_INIT_LOADADDR_EXTRA_DECLS
# define DL_INIT_LOADADDR_EXTRA_DECLS /* int i; */
#endif

/* Prepare a DL_LOADADDR_TYPE data structure for incremental
 * initialization with DL_INIT_LOADADDR_HDR, given pointers to a base
 * load address and to program headers.
 */
#ifndef DL_INIT_LOADADDR
# define DL_INIT_LOADADDR(LOADADDR, BASEADDR, PHDR, PHDRCNT) \
	((LOADADDR) = (BASEADDR))
#endif

/* Initialize a LOADADDR representing the program.  It's called from
 * DL_BOOT only.
 */
#ifndef DL_INIT_LOADADDR_PROG
# define DL_INIT_LOADADDR_PROG(LOADADDR, BASEADDR) \
	((LOADADDR) = (DL_LOADADDR_TYPE)(BASEADDR))
#endif

/* Update LOADADDR with information about PHDR, just mapped to the
   given ADDR.  */
#ifndef DL_INIT_LOADADDR_HDR
# define DL_INIT_LOADADDR_HDR(LOADADDR, ADDR, PHDR) /* Do nothing.  */
#endif

/* Convert a DL_LOADADDR_TYPE to an identifying pointer.  Used mostly
 * for debugging.
 */
#ifndef DL_LOADADDR_BASE
# define DL_LOADADDR_BASE(LOADADDR) (LOADADDR)
#endif

/* Test whether a given ADDR is more likely to be within the memory
 * region mapped to TPNT (a struct elf_resolve *) than to TFROM.
 * Everywhere that this is used, TFROM is initially NULL, and whenever
 * a potential match is found, it's updated.  One might want to walk
 * the chain of elf_resolve to locate the best match and return false
 * whenever TFROM is non-NULL, or use an exact-matching algorithm
 * using additional information encoded in DL_LOADADDR_TYPE to test
 * for exact containment.
 */
#ifndef DL_ADDR_IN_LOADADDR
# define DL_ADDR_IN_LOADADDR(ADDR, TPNT, TFROM) \
	((void*)(TPNT)->mapaddr < (void*)(ADDR) \
	 && (!(TFROM) || (TFROM)->mapaddr < (TPNT)->mapaddr))
#endif

/* This is called from dladdr() to give targets that use function descriptors
 * a chance to map a function descriptor's address to the function's entry
 * point before trying to find in which library it's defined.  */
#ifndef DL_LOOKUP_ADDRESS
#define DL_LOOKUP_ADDRESS(ADDRESS) (ADDRESS)
#endif

/* Use this macro to convert a pointer to a function's entry point to
 * a pointer to function.  The pointer is assumed to have already been
 * relocated.  LOADADDR is passed because it may contain additional
 * information needed to compute the pointer to function.
 */
#ifndef DL_ADDR_TO_FUNC_PTR
# define DL_ADDR_TO_FUNC_PTR(ADDR, LOADADDR) ((void(*)(void))(ADDR))
#endif

/* On some platforms, computing a pointer to function is more
   expensive than calling a function at a given address, so this
   alternative is provided.  The function signature must be given
   within parentheses, as in a type cast.  */
#ifndef DL_CALL_FUNC_AT_ADDR
# define DL_CALL_FUNC_AT_ADDR(ADDR, LOADADDR, SIGNATURE, ...) \
  ((*SIGNATURE DL_ADDR_TO_FUNC_PTR ((ADDR), (LOADADDR)))(__VA_ARGS__))
#endif

/* An alignment value for a memory block returned by _dl_malloc. */
#ifndef DL_MALLOC_ALIGN
# define DL_MALLOC_ALIGN (__WORDSIZE / 8)
#endif

#ifdef __UCLIBC_UNDERSCORES__
# define __C_SYMBOL_PREFIX__ "_"
#else
# define __C_SYMBOL_PREFIX__ ""
#endif

/* Define this if you want to modify the VALUE returned by
   _dl_find_hash for this reloc TYPE.  TPNT is the module in which the
   matching SYM was found.  */
#ifndef DL_FIND_HASH_VALUE
# define DL_FIND_HASH_VALUE(TPNT, TYPE, SYM) (DL_RELOC_ADDR ((TPNT)->loadaddr, (SYM)->st_value))
#endif

/* Unmap all previously-mapped segments accumulated in LOADADDR.
   Generally used when an error occurs during loading.  */
#ifndef DL_LOADADDR_UNMAP
# define DL_LOADADDR_UNMAP(LOADADDR, LEN) \
  _dl_munmap((char *) (LOADADDR), (LEN))
#endif

/* Similar to DL_LOADADDR_UNMAP, but used for libraries that have been
   dlopen()ed successfully, when they're dlclose()d.  */
#ifndef DL_LIB_UNMAP
# define DL_LIB_UNMAP(LIB, LEN) (DL_LOADADDR_UNMAP ((LIB)->loadaddr, (LEN)))
#endif

/* Define this to verify that a library named LIBNAME, whose ELF
   headers are pointed to by EPNT, is suitable for dynamic linking.
   If it is not, print an error message (optional) and return NULL.
   If the library can have its segments relocated independently,
   arrange for PICLIB to be set to 2.  If all segments have to be
   relocated by the same amount, set it to 1.  If it has to be loaded
   at physical addresses as specified in the program headers, set it
   to 0.  A reasonable (?) guess for PICLIB will already be in place,
   so it is safe to do nothing here.  */
#ifndef DL_CHECK_LIB_TYPE
# define DL_CHECK_LIB_TYPE(EPNT, PICLIB, PROGNAME, LIBNAME) (void)0
#endif

/* Define this if you have special segment.  */
#ifndef DL_IS_SPECIAL_SEGMENT
# define DL_IS_SPECIAL_SEGMENT(EPNT, PPNT) 0
#endif

/* Define this if you want to use special method to map the segment.  */
#ifndef DL_MAP_SEGMENT
# define DL_MAP_SEGMENT(EPNT, PPNT, INFILE, FLAGS) 0
#endif

#endif	/* _LD_DEFS_H */