aad599979d
_rtld_tls_allocate and _rtld_tls_free. libpthread uses this functions to setup the thread private area of all new threads. ld.elf_so is responsible for setting up the private area for the initial thread. Similar functions are called from _libc_init for static binaries, using dl_iterate_phdr to access the ELF Program Header. Add test cases to exercise the different TLS storage models. Test cases are compiled and installed on all platforms, but are skipped on platforms not marked for TLS support. This material is based upon work partially supported by The NetBSD Foundation under a contract with Joerg Sonnenberger. It is inspired by the TLS support in FreeBSD by Doug Rabson and the clean ups of the DragonFly port of the original FreeBSD modifications.
396 lines
14 KiB
C
396 lines
14 KiB
C
/* $NetBSD: rtld.h,v 1.101 2011/03/09 23:10:07 joerg Exp $ */
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/*
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* Copyright 1996 John D. Polstra.
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* Copyright 1996 Matt Thomas <matt@3am-software.com>
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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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* 3. All advertising materials mentioning features or use of this software
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* must display the following acknowledgement:
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* This product includes software developed by John Polstra.
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* 4. The name of the author may not be used to endorse or promote products
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* derived from this software without specific prior written permission.
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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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#ifndef RTLD_H
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#define RTLD_H
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#include <dlfcn.h>
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#include <stdbool.h>
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#include <stddef.h>
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#include <sys/param.h>
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#include <sys/types.h>
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#include <sys/queue.h>
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#include <sys/exec_elf.h>
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#include <sys/tls.h>
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#include "rtldenv.h"
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#include "link.h"
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#if defined(_RTLD_SOURCE)
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#ifndef RTLD_DEFAULT_LIBRARY_PATH
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#define RTLD_DEFAULT_LIBRARY_PATH "/usr/lib"
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#endif
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#define _PATH_LD_HINTS "/etc/ld.so.conf"
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extern size_t _rtld_pagesz;
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#define round_down(x) ((x) & ~(_rtld_pagesz - 1))
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#define round_up(x) round_down((x) + _rtld_pagesz - 1)
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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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/*
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* Fill in a DoneList with an allocation large enough to hold all of
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* the currently-loaded objects. Keep this in a macro since it calls
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* alloca and we want that to occur within the scope of the caller.
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*/
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#define _rtld_donelist_init(dlp) \
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((dlp)->num_alloc = _rtld_objcount, \
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(dlp)->objs = alloca((dlp)->num_alloc * sizeof((dlp)->objs[0])), \
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assert((dlp)->objs != NULL), \
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(dlp)->num_used = 0)
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#endif /* _RTLD_SOURCE */
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/*
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* C++ has mandated the use of the following keywords for its new boolean
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* type. We might as well follow their lead.
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*/
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struct Struct_Obj_Entry;
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typedef struct Struct_Objlist_Entry {
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SIMPLEQ_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 SIMPLEQ_HEAD(Struct_Objlist, Struct_Objlist_Entry) Objlist;
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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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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 _rtld_search_path_t {
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struct _rtld_search_path_t *sp_next;
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const char *sp_path;
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size_t sp_pathlen;
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} Search_Path;
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#define RTLD_MAX_ENTRY 10
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#define RTLD_MAX_LIBRARY 4
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#define RTLD_MAX_CTL 2
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typedef struct _rtld_library_xform_t {
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struct _rtld_library_xform_t *next;
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char *name;
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const char *ctlname;
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struct {
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char *value;
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char *library[RTLD_MAX_LIBRARY];
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} entry[RTLD_MAX_ENTRY];
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} Library_Xform;
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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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* The layout of this structure needs to be preserved because pre-2.0 binaries
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* hard-coded the location of dlopen() and friends.
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*/
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#define RTLD_MAGIC 0xd550b87a
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#define RTLD_VERSION 1
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typedef struct Struct_Obj_Entry {
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Elf32_Word magic; /* Magic number (sanity check) */
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Elf32_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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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; /* Reloc const = mapbase - *vaddrbase */
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Elf_Dyn *dynamic; /* Dynamic section */
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caddr_t entry; /* Entry point */
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const Elf_Phdr *phdr; /* Program header (may be xmalloc'ed) */
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size_t phsize; /* Size of program header in bytes */
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/* Items from the dynamic section. */
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Elf_Addr *pltgot; /* PLTGOT table */
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const Elf_Rel *rel; /* Relocation entries */
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const Elf_Rel *rellim; /* Limit of Relocation entries */
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const Elf_Rela *rela; /* Relocation entries */
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const Elf_Rela *relalim; /* Limit of Relocation entries */
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const Elf_Rel *pltrel; /* PLT relocation entries */
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const Elf_Rel *pltrellim; /* Limit of PLT relocation entries */
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const Elf_Rela *pltrela; /* PLT relocation entries */
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const Elf_Rela *pltrelalim; /* Limit of PLT relocation entries */
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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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#endif
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const Elf_Symindx *buckets; /* Hash table buckets array */
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unsigned long unused1; /* Used to be nbuckets */
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const Elf_Symindx *chains; /* Hash table chain array */
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unsigned long nchains; /* Number of chains */
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Search_Path *rpaths; /* Search path specified in object */
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Needed_Entry *needed; /* Shared objects needed by this (%) */
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void (*init)(void); /* Initialization function to call */
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void (*fini)(void); /* Termination function to call */
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/* Entry points for dlopen() and friends. */
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void *(*dlopen)(const char *, int);
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void *(*dlsym)(void *, const char *);
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char *(*dlerror)(void);
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int (*dlclose)(void *);
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int (*dladdr)(const void *, Dl_info *);
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u_int32_t mainprog:1, /* True if this is the main program */
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rtld:1, /* True if this is the dynamic linker */
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textrel:1, /* True if there are relocations to
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* text seg */
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symbolic:1, /* True if generated with
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* "-Bsymbolic" */
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printed:1, /* True if ldd has printed it */
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isdynamic:1, /* True if this is a pure PIC object */
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mainref:1, /* True if on _rtld_list_main */
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globalref:1, /* True if on _rtld_list_global */
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init_done:1, /* True if .init has been added */
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init_called:1, /* True if .init function has been
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* called */
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fini_called:1, /* True if .fini function has been
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* called */
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z_now:1, /* True if object's symbols should be
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bound immediately */
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z_nodelete:1, /* True if object should never be
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unloaded */
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z_initfirst:1, /* True if object's .init/.fini take
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* priority over others */
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z_noopen:1, /* True if object should never be
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dlopen'ed */
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phdr_loaded:1, /* Phdr is loaded and doesn't need to
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* be freed. */
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#if defined(__HAVE_TLS_VARIANT_I) || defined(__HAVE_TLS_VARIANT_II)
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tls_done:1, /* True if static TLS offset
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* has been allocated */
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#endif
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ref_nodel:1; /* Refcount increased to prevent dlclose */
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struct link_map linkmap; /* for GDB */
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/* These items are computed by map_object() or by digest_phdr(). */
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const char *interp; /* Pathname of the interpreter, if any */
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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 *ehdr;
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uint32_t nbuckets; /* Number of buckets */
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uint32_t nbuckets_m; /* Precomputed for fast remainder */
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uint8_t nbuckets_s1;
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uint8_t nbuckets_s2;
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size_t pathlen; /* Pathname length */
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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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#ifdef __powerpc__
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Elf_Addr *gotptr; /* GOT table (secure-plt only) */
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#endif
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#if defined(__HAVE_TLS_VARIANT_I) || defined(__HAVE_TLS_VARIANT_II)
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/* Thread Local Storage support for this module */
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size_t tlsindex; /* Index in DTV */
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void *tlsinit; /* Base address of TLS init block */
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size_t tlsinitsize; /* Size of TLS init block */
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size_t tlssize; /* Size of TLS block */
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size_t tlsoffset; /* Offset in the static TLS block */
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size_t tlsalign; /* Needed alignment for static TLS */
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#endif
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} Obj_Entry;
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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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#if defined(_RTLD_SOURCE)
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extern struct r_debug _rtld_debug;
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extern Search_Path *_rtld_default_paths;
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extern Obj_Entry *_rtld_objlist;
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extern Obj_Entry **_rtld_objtail;
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extern u_int _rtld_objcount;
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extern u_int _rtld_objloads;
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extern Obj_Entry *_rtld_objmain;
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extern Obj_Entry _rtld_objself;
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extern Search_Path *_rtld_paths;
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extern Library_Xform *_rtld_xforms;
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extern bool _rtld_trust;
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extern Objlist _rtld_list_global;
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extern Objlist _rtld_list_main;
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extern Elf_Sym _rtld_sym_zero;
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#define RTLD_MODEMASK 0x3
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/* Flags for _rtld_load_object() and friends. */
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#define _RTLD_GLOBAL 0x01 /* Add object to global DAG. */
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#define _RTLD_MAIN 0x02
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#define _RTLD_NOLOAD 0x04 /* dlopen() specified RTLD_NOLOAD. */
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#define _RTLD_DLOPEN 0x08 /* Load_object() called from dlopen(). */
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/* Preallocation for static TLS model */
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#define RTLD_STATIC_TLS_RESERVATION 64
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/* rtld.c */
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/* We export these symbols using _rtld_symbol_lookup and is_exported. */
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__dso_public char *dlerror(void);
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__dso_public void *dlopen(const char *, int);
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__dso_public void *dlsym(void *, const char *);
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__dso_public int dlclose(void *);
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__dso_public int dladdr(const void *, Dl_info *);
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__dso_public int dlinfo(void *, int, void *);
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__dso_public int dl_iterate_phdr(int (*)(struct dl_phdr_info *, size_t, void *),
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void *);
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/* These aren't exported */
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void _rtld_error(const char *, ...)
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__attribute__((__format__(__printf__,1,2)));
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void _rtld_die(void) __attribute__((__noreturn__));
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void *_rtld_objmain_sym(const char *);
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__dso_public void _rtld_debug_state(void);
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void _rtld_linkmap_add(Obj_Entry *);
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void _rtld_linkmap_delete(Obj_Entry *);
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void _rtld_objlist_push_head(Objlist *, Obj_Entry *);
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void _rtld_objlist_push_tail(Objlist *, Obj_Entry *);
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Objlist_Entry *_rtld_objlist_find(Objlist *, const Obj_Entry *);
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void _rtld_ref_dag(Obj_Entry *);
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/* expand.c */
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size_t _rtld_expand_path(char *, size_t, const char *, const char *,\
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const char *);
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/* headers.c */
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void _rtld_digest_dynamic(const char *, Obj_Entry *);
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Obj_Entry *_rtld_digest_phdr(const Elf_Phdr *, int, caddr_t);
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/* load.c */
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Obj_Entry *_rtld_load_object(const char *, int);
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int _rtld_load_needed_objects(Obj_Entry *, int);
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int _rtld_preload(const char *);
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#define OBJ_ERR (Obj_Entry *)(-1)
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/* path.c */
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void _rtld_add_paths(const char *, Search_Path **, const char *);
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void _rtld_process_hints(const char *, Search_Path **, Library_Xform **,
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const char *);
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int _rtld_sysctl(const char *, void *, size_t *);
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/* reloc.c */
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int _rtld_do_copy_relocations(const Obj_Entry *);
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int _rtld_relocate_objects(Obj_Entry *, bool);
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int _rtld_relocate_nonplt_objects(Obj_Entry *);
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int _rtld_relocate_plt_lazy(const Obj_Entry *);
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int _rtld_relocate_plt_objects(const Obj_Entry *);
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void _rtld_setup_pltgot(const Obj_Entry *);
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/* search.c */
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Obj_Entry *_rtld_load_library(const char *, const Obj_Entry *, int);
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/* symbol.c */
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unsigned long _rtld_elf_hash(const char *);
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const Elf_Sym *_rtld_symlook_obj(const char *, unsigned long,
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const Obj_Entry *, bool);
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const Elf_Sym *_rtld_find_symdef(unsigned long, const Obj_Entry *,
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const Obj_Entry **, bool);
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const Elf_Sym *_rtld_find_plt_symdef(unsigned long, const Obj_Entry *,
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const Obj_Entry **, bool);
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const Elf_Sym *_rtld_symlook_list(const char *, unsigned long,
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const Objlist *, const Obj_Entry **, bool, DoneList *);
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const Elf_Sym *_rtld_symlook_default(const char *, unsigned long,
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const Obj_Entry *, const Obj_Entry **, bool);
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const Elf_Sym *_rtld_symlook_needed(const char *, unsigned long,
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const Needed_Entry *, const Obj_Entry **, bool,
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DoneList *, DoneList *);
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#ifdef COMBRELOC
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void _rtld_combreloc_reset(const Obj_Entry *);
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#endif
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#if defined(__HAVE_TLS_VARIANT_I) || defined(__HAVE_TLS_VARIANT_II)
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/* tls.c */
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void *_rtld_tls_get_addr(void *, size_t, size_t);
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void _rtld_tls_initial_allocation(void);
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void *_rtld_tls_module_allocate(size_t index);
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int _rtld_tls_offset_allocate(Obj_Entry *);
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void _rtld_tls_offset_free(Obj_Entry *);
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extern size_t _rtld_tls_dtv_generation;
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extern size_t _rtld_tls_max_index;
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__dso_public extern void __tls_get_addr(void *);
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#endif
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/* map_object.c */
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struct stat;
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Obj_Entry *_rtld_map_object(const char *, int, const struct stat *);
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void _rtld_obj_free(Obj_Entry *);
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Obj_Entry *_rtld_obj_new(void);
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/* function descriptors */
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#ifdef __HAVE_FUNCTION_DESCRIPTORS
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Elf_Addr _rtld_function_descriptor_alloc(const Obj_Entry *,
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const Elf_Sym *, Elf_Addr);
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const void *_rtld_function_descriptor_function(const void *);
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#endif /* __HAVE_FUNCTION_DESCRIPTORS */
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#endif /* _RTLD_SOURCE */
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#endif /* RTLD_H */
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