41fc6f680b
objects' init functions instead of doing the setup via a constructor
in libc as the init functions may already depend on these handlers
to be in place. This gets us rid of:
- the undefined order in which libc constructors as __guard_setup()
and jemalloc_constructor() are executed WRT __sparc_utrap_setup(),
- the requirement to link libc last so __sparc_utrap_setup() gets
called prior to constructors in other libraries (see r122883).
For static binaries, crt1.o still sets up the user trap handlers.
o Move misplaced prototypes for MD functions in to the MD prototype
section of rtld.h.
o Sprinkle nitems().
412 lines
16 KiB
C
412 lines
16 KiB
C
/*-
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* SPDX-License-Identifier: BSD-2-Clause-FreeBSD
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*
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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 <stdarg.h>
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#include <setjmp.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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#define NEW(type) ((type *) xmalloc(sizeof(type)))
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#define CNEW(type) ((type *) xcalloc(1, 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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extern size_t tls_last_offset;
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extern size_t tls_last_size;
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extern size_t tls_static_space;
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extern int tls_dtv_generation;
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extern int tls_max_index;
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extern int npagesizes;
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extern size_t *pagesizes;
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extern int main_argc;
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extern char **main_argv;
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extern char **environ;
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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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typedef void (*InitArrFunc)(int, char **, char **);
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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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typedef struct Struct_Name_Entry {
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STAILQ_ENTRY(Struct_Name_Entry) link;
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char name[1];
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} Name_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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typedef struct Struct_Ver_Entry {
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Elf_Word hash;
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unsigned int flags;
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const char *name;
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const char *file;
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} Ver_Entry;
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typedef struct Struct_Sym_Match_Result {
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const Elf_Sym *sym_out;
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const Elf_Sym *vsymp;
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int vcount;
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} Sym_Match_Result;
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#define VER_INFO_HIDDEN 0x01
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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_Size magic; /* Magic number (sanity check) */
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Elf_Size version; /* Version number of struct format */
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TAILQ_ENTRY(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; /* DAG references */
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int holdcount; /* Count of transient references */
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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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Elf_Word stack_flags;
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/* TLS information */
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int tlsindex; /* Index in DTV for this module */
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void *tlsinit; /* Base address of TLS init block */
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size_t tlsinitsize; /* Size of TLS init block for this module */
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size_t tlssize; /* Size of TLS block for this module */
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size_t tlsoffset; /* Offset of static TLS block for this module */
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size_t tlsalign; /* Alignment of static TLS block */
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caddr_t relro_page;
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size_t relro_size;
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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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#ifdef __mips__
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Elf_Word local_gotno; /* Number of local GOT entries */
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Elf_Word symtabno; /* Number of dynamic symbols */
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Elf_Word gotsym; /* First dynamic symbol in GOT */
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Elf_Addr *mips_pltgot; /* Second PLT GOT */
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#endif
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#ifdef __powerpc64__
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Elf_Addr glink; /* GLINK PLT call stub section */
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#endif
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const Elf_Verneed *verneed; /* Required versions. */
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Elf_Word verneednum; /* Number of entries in verneed table */
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const Elf_Verdef *verdef; /* Provided versions. */
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Elf_Word verdefnum; /* Number of entries in verdef table */
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const Elf_Versym *versyms; /* Symbol versions 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 entries in chain array */
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Elf32_Word nbuckets_gnu; /* Number of GNU hash buckets*/
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Elf32_Word symndx_gnu; /* 1st accessible symbol on dynsym table */
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Elf32_Word maskwords_bm_gnu; /* Bloom filter words - 1 (bitmask) */
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Elf32_Word shift2_gnu; /* Bloom filter shift count */
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Elf32_Word dynsymcount; /* Total entries in dynsym table */
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Elf_Addr *bloom_gnu; /* Bloom filter used by GNU hash func */
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const Elf_Hashelt *buckets_gnu; /* GNU hash table bucket array */
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const Elf_Hashelt *chain_zero_gnu; /* GNU hash table value array (Zeroed) */
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char *rpath; /* Search path specified in object */
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char *runpath; /* Search path with different priority */
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Needed_Entry *needed; /* Shared objects needed by this one (%) */
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Needed_Entry *needed_filtees;
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Needed_Entry *needed_aux_filtees;
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STAILQ_HEAD(, Struct_Name_Entry) names; /* List of names for this object we
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know about. */
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Ver_Entry *vertab; /* Versions required /defined by this object */
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int vernum; /* Number of entries in vertab */
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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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Elf_Addr preinit_array; /* Pre-initialization array of functions */
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Elf_Addr init_array; /* Initialization array of functions */
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Elf_Addr fini_array; /* Termination array of functions */
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int preinit_array_num; /* Number of entries in preinit_array */
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int init_array_num; /* Number of entries in init_array */
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int fini_array_num; /* Number of entries in fini_array */
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int32_t osrel; /* OSREL note value */
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bool mainprog : 1; /* True if this is the main program */
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bool rtld : 1; /* True if this is the dynamic linker */
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bool relocated : 1; /* True if processed by relocate_objects() */
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bool ver_checked : 1; /* True if processed by rtld_verify_object_versions */
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bool textrel : 1; /* True if there are relocations to text seg */
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bool symbolic : 1; /* True if generated with "-Bsymbolic" */
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bool bind_now : 1; /* True if all relocations should be made first */
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bool traced : 1; /* Already printed in ldd trace output */
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bool jmpslots_done : 1; /* Already have relocated the jump slots */
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bool init_done : 1; /* Already have added object to init list */
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bool tls_done : 1; /* Already allocated offset for static TLS */
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bool phdr_alloc : 1; /* Phdr is allocated and needs to be freed. */
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bool z_origin : 1; /* Process rpath and soname tokens */
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bool z_nodelete : 1; /* Do not unload the object and dependencies */
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bool z_noopen : 1; /* Do not load on dlopen */
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bool z_loadfltr : 1; /* Immediately load filtees */
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bool z_interpose : 1; /* Interpose all objects but main */
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bool z_nodeflib : 1; /* Don't search default library path */
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bool z_global : 1; /* Make the object global */
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bool ref_nodel : 1; /* Refcount increased to prevent dlclose */
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bool init_scanned: 1; /* Object is already on init list. */
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bool on_fini_list: 1; /* Object is already on fini list. */
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bool dag_inited : 1; /* Object has its DAG initialized. */
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bool filtees_loaded : 1; /* Filtees loaded */
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bool irelative : 1; /* Object has R_MACHDEP_IRELATIVE relocs */
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bool gnu_ifunc : 1; /* Object has references to STT_GNU_IFUNC */
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bool non_plt_gnu_ifunc : 1; /* Object has non-plt IFUNC references */
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bool crt_no_init : 1; /* Object' crt does not call _init/_fini */
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bool valid_hash_sysv : 1; /* A valid System V hash hash tag is available */
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bool valid_hash_gnu : 1; /* A valid GNU hash tag is available */
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bool dlopened : 1; /* dlopen()-ed (vs. load statically) */
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bool marker : 1; /* marker on the global obj list */
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bool unholdfree : 1; /* unmap upon last unhold */
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bool doomed : 1; /* Object cannot be referenced */
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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-dependent */
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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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TAILQ_HEAD(obj_entry_q, Struct_Obj_Entry);
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#define RTLD_STATIC_TLS_EXTRA 128
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/* Flags to be passed into symlook_ family of functions. */
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#define SYMLOOK_IN_PLT 0x01 /* Lookup for PLT symbol */
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#define SYMLOOK_DLSYM 0x02 /* Return newest versioned symbol. Used by
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dlsym. */
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#define SYMLOOK_EARLY 0x04 /* Symlook is done during initialization. */
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#define SYMLOOK_IFUNC 0x08 /* Allow IFUNC processing in
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reloc_non_plt(). */
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/* Flags for load_object(). */
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#define RTLD_LO_NOLOAD 0x01 /* dlopen() specified RTLD_NOLOAD. */
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#define RTLD_LO_DLOPEN 0x02 /* Load_object() called from dlopen(). */
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#define RTLD_LO_TRACE 0x04 /* Only tracing. */
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#define RTLD_LO_NODELETE 0x08 /* Loaded object cannot be closed. */
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#define RTLD_LO_FILTEES 0x10 /* Loading filtee. */
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#define RTLD_LO_EARLY 0x20 /* Do not call ctors, postpone it to the
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initialization during the image start. */
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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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/*
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* This structure provides a reentrant way to keep a list of objects and
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* check which ones have already been processed in some way.
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*/
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typedef struct Struct_DoneList {
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const Obj_Entry **objs; /* Array of object pointers */
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unsigned int num_alloc; /* Allocated size of the array */
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unsigned int num_used; /* Number of array slots used */
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} DoneList;
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struct Struct_RtldLockState {
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int lockstate;
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sigjmp_buf env;
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};
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struct fill_search_info_args {
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int request;
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unsigned int flags;
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struct dl_serinfo *serinfo;
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struct dl_serpath *serpath;
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char *strspace;
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};
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/*
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* The pack of arguments and results for the symbol lookup functions.
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*/
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typedef struct Struct_SymLook {
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const char *name;
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unsigned long hash;
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uint32_t hash_gnu;
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const Ver_Entry *ventry;
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int flags;
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const Obj_Entry *defobj_out;
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const Elf_Sym *sym_out;
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struct Struct_RtldLockState *lockstate;
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} SymLook;
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void _rtld_error(const char *, ...) __printflike(1, 2) __exported;
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void rtld_die(void) __dead2;
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const char *rtld_strerror(int);
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Obj_Entry *map_object(int, const char *, const struct stat *);
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void *xcalloc(size_t, size_t);
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void *xmalloc(size_t);
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char *xstrdup(const char *);
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void *malloc_aligned(size_t size, size_t align);
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void free_aligned(void *ptr);
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extern Elf_Addr _GLOBAL_OFFSET_TABLE_[];
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extern Elf_Sym sym_zero; /* For resolving undefined weak refs. */
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extern bool ld_bind_not;
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void dump_relocations(Obj_Entry *);
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void dump_obj_relocations(Obj_Entry *);
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void dump_Elf_Rel(Obj_Entry *, const Elf_Rel *, u_long);
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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 **, int, SymCache *, struct Struct_RtldLockState *);
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void lockdflt_init(void);
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void digest_notes(Obj_Entry *, Elf_Addr, Elf_Addr);
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Obj_Entry *globallist_curr(const Obj_Entry *obj);
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Obj_Entry *globallist_next(const Obj_Entry *obj);
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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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void *rtld_resolve_ifunc(const Obj_Entry *obj, const Elf_Sym *def);
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void symlook_init(SymLook *, const char *);
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int symlook_obj(SymLook *, const Obj_Entry *);
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void *tls_get_addr_common(Elf_Addr** dtvp, int index, size_t offset);
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void *allocate_tls(Obj_Entry *, void *, size_t, size_t);
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void free_tls(void *, size_t, size_t);
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void *allocate_module_tls(int index);
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bool allocate_tls_offset(Obj_Entry *obj);
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void free_tls_offset(Obj_Entry *obj);
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const Ver_Entry *fetch_ventry(const Obj_Entry *obj, unsigned long);
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int convert_prot(int elfflags);
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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 *, int flags,
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struct Struct_RtldLockState *);
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int reloc_plt(Obj_Entry *);
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int reloc_jmpslots(Obj_Entry *, int flags, struct Struct_RtldLockState *);
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int reloc_iresolve(Obj_Entry *, struct Struct_RtldLockState *);
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int reloc_gnu_ifunc(Obj_Entry *, int flags, struct Struct_RtldLockState *);
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void ifunc_init(Elf_Auxinfo[__min_size(AT_COUNT)]);
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void pre_init(void);
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void init_pltgot(Obj_Entry *);
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void allocate_initial_tls(Obj_Entry *);
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#endif /* } */
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