ca4dc26350
Setting the LD_DUMP_REL_PRE or LD_DUMP_REL_POST environment variables cause rtld-elf to output a table of all relocations. This is useful for debugging.
217 lines
7.9 KiB
C
217 lines
7.9 KiB
C
/*-
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* Copyright 1996, 1997, 1998, 1999, 2000 John D. Polstra.
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* All rights reserved.
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*
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* Redistribution and use in source and binary forms, with or without
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* modification, are permitted provided that the following conditions
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* are met:
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* 1. Redistributions of source code must retain the above copyright
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* notice, this list of conditions and the following disclaimer.
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* 2. Redistributions in binary form must reproduce the above copyright
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* notice, this list of conditions and the following disclaimer in the
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* documentation and/or other materials provided with the distribution.
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*
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* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
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* IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
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* OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
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* IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
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* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
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* NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
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* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
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* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
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* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
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* THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
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*
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* $FreeBSD$
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*/
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#ifndef RTLD_H /* { */
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#define RTLD_H 1
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#include <machine/elf.h>
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#include <sys/types.h>
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#include <sys/queue.h>
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#include <elf-hints.h>
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#include <link.h>
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#include <stddef.h>
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#include "rtld_lock.h"
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#include "rtld_machdep.h"
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#ifndef STANDARD_LIBRARY_PATH
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#define STANDARD_LIBRARY_PATH "/usr/lib"
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#endif
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#define NEW(type) ((type *) xmalloc(sizeof(type)))
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#define CNEW(type) ((type *) xcalloc(sizeof(type)))
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/* We might as well do booleans like C++. */
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typedef unsigned char bool;
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#define false 0
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#define true 1
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struct stat;
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struct Struct_Obj_Entry;
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/* Lists of shared objects */
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typedef struct Struct_Objlist_Entry {
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STAILQ_ENTRY(Struct_Objlist_Entry) link;
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struct Struct_Obj_Entry *obj;
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} Objlist_Entry;
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typedef STAILQ_HEAD(Struct_Objlist, Struct_Objlist_Entry) Objlist;
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/* Types of init and fini functions */
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typedef void (*InitFunc)(void);
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/* Lists of shared object dependencies */
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typedef struct Struct_Needed_Entry {
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struct Struct_Needed_Entry *next;
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struct Struct_Obj_Entry *obj;
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unsigned long name; /* Offset of name in string table */
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} Needed_Entry;
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/* Lock object */
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typedef struct Struct_LockInfo {
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void *context; /* Client context for creating locks */
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void *thelock; /* The one big lock */
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/* Debugging aids. */
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volatile int rcount; /* Number of readers holding lock */
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volatile int wcount; /* Number of writers holding lock */
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/* Methods */
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void *(*lock_create)(void *context);
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void (*rlock_acquire)(void *lock);
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void (*wlock_acquire)(void *lock);
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void (*rlock_release)(void *lock);
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void (*wlock_release)(void *lock);
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void (*lock_destroy)(void *lock);
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void (*context_destroy)(void *context);
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} LockInfo;
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/*
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* Shared object descriptor.
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*
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* Items marked with "(%)" are dynamically allocated, and must be freed
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* when the structure is destroyed.
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*
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* CAUTION: It appears that the JDK port peeks into these structures.
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* It looks at "next" and "mapbase" at least. Don't add new members
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* near the front, until this can be straightened out.
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*/
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typedef struct Struct_Obj_Entry {
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/*
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* These two items have to be set right for compatibility with the
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* original ElfKit crt1.o.
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*/
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Elf_Word magic; /* Magic number (sanity check) */
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Elf_Word version; /* Version number of struct format */
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struct Struct_Obj_Entry *next;
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char *path; /* Pathname of underlying file (%) */
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char *origin_path; /* Directory path of origin file */
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int refcount;
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int dl_refcount; /* Number of times loaded by dlopen */
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/* These items are computed by map_object() or by digest_phdr(). */
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caddr_t mapbase; /* Base address of mapped region */
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size_t mapsize; /* Size of mapped region in bytes */
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size_t textsize; /* Size of text segment in bytes */
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Elf_Addr vaddrbase; /* Base address in shared object file */
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caddr_t relocbase; /* Relocation constant = mapbase - vaddrbase */
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const Elf_Dyn *dynamic; /* Dynamic section */
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caddr_t entry; /* Entry point */
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const Elf_Phdr *phdr; /* Program header if it is mapped, else NULL */
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size_t phsize; /* Size of program header in bytes */
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const char *interp; /* Pathname of the interpreter, if any */
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/* Items from the dynamic section. */
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Elf_Addr *pltgot; /* PLT or GOT, depending on architecture */
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const Elf_Rel *rel; /* Relocation entries */
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unsigned long relsize; /* Size in bytes of relocation info */
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const Elf_Rela *rela; /* Relocation entries with addend */
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unsigned long relasize; /* Size in bytes of addend relocation info */
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const Elf_Rel *pltrel; /* PLT relocation entries */
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unsigned long pltrelsize; /* Size in bytes of PLT relocation info */
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const Elf_Rela *pltrela; /* PLT relocation entries with addend */
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unsigned long pltrelasize; /* Size in bytes of PLT addend reloc info */
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const Elf_Sym *symtab; /* Symbol table */
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const char *strtab; /* String table */
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unsigned long strsize; /* Size in bytes of string table */
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const Elf_Hashelt *buckets; /* Hash table buckets array */
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unsigned long nbuckets; /* Number of buckets */
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const Elf_Hashelt *chains; /* Hash table chain array */
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unsigned long nchains; /* Number of chains */
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const char *rpath; /* Search path specified in object */
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Needed_Entry *needed; /* Shared objects needed by this one (%) */
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Elf_Addr init; /* Initialization function to call */
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Elf_Addr fini; /* Termination function to call */
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bool mainprog; /* True if this is the main program */
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bool rtld; /* True if this is the dynamic linker */
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bool textrel; /* True if there are relocations to text seg */
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bool symbolic; /* True if generated with "-Bsymbolic" */
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bool bind_now; /* True if all relocations should be made first */
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bool traced; /* Already printed in ldd trace output */
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bool jmpslots_done; /* Already have relocated the jump slots */
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bool init_done; /* Already have added object to init list */
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struct link_map linkmap; /* for GDB and dlinfo() */
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Objlist dldags; /* Object belongs to these dlopened DAGs (%) */
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Objlist dagmembers; /* DAG has these members (%) */
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dev_t dev; /* Object's filesystem's device */
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ino_t ino; /* Object's inode number */
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void *priv; /* Platform-dependant */
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} Obj_Entry;
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#define RTLD_MAGIC 0xd550b87a
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#define RTLD_VERSION 1
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/*
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* Symbol cache entry used during relocation to avoid multiple lookups
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* of the same symbol.
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*/
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typedef struct Struct_SymCache {
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const Elf_Sym *sym; /* Symbol table entry */
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const Obj_Entry *obj; /* Shared object which defines it */
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} SymCache;
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extern void _rtld_error(const char *, ...) __printflike(1, 2);
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extern Obj_Entry *map_object(int, const char *, const struct stat *);
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extern void *xcalloc(size_t);
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extern void *xmalloc(size_t);
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extern char *xstrdup(const char *);
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extern Elf_Addr _GLOBAL_OFFSET_TABLE_[];
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extern void dump_relocations (Obj_Entry *);
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extern void dump_obj_relocations (Obj_Entry *);
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extern void dump_Elf_Rel (Obj_Entry *, const Elf_Rel *, u_long);
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extern void dump_Elf_Rela (Obj_Entry *, const Elf_Rela *, u_long);
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/*
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* Function declarations.
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*/
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unsigned long elf_hash(const char *);
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const Elf_Sym *find_symdef(unsigned long, const Obj_Entry *,
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const Obj_Entry **, bool, SymCache *);
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void init_pltgot(Obj_Entry *);
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void lockdflt_init(void);
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void obj_free(Obj_Entry *);
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Obj_Entry *obj_new(void);
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void _rtld_bind_start(void);
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const Elf_Sym *symlook_obj(const char *, unsigned long,
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const Obj_Entry *, bool);
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/*
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* MD function declarations.
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*/
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int do_copy_relocations(Obj_Entry *);
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int reloc_non_plt(Obj_Entry *, Obj_Entry *);
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int reloc_plt(Obj_Entry *);
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int reloc_jmpslots(Obj_Entry *);
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#endif /* } */
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