4884 lines
129 KiB
C
4884 lines
129 KiB
C
/*-
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* Copyright 1996, 1997, 1998, 1999, 2000 John D. Polstra.
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* Copyright 2003 Alexander Kabaev <kan@FreeBSD.ORG>.
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* Copyright 2009-2012 Konstantin Belousov <kib@FreeBSD.ORG>.
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* Copyright 2012 John Marino <draco@marino.st>.
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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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/*
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* Dynamic linker for ELF.
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*
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* John Polstra <jdp@polstra.com>.
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*/
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#ifndef __GNUC__
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#error "GCC is needed to compile this file"
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#endif
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#include <sys/param.h>
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#include <sys/mount.h>
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#include <sys/mman.h>
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#include <sys/stat.h>
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#include <sys/sysctl.h>
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#include <sys/uio.h>
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#include <sys/utsname.h>
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#include <sys/ktrace.h>
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#include <dlfcn.h>
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#include <err.h>
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#include <errno.h>
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#include <fcntl.h>
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#include <stdarg.h>
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#include <stdio.h>
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#include <stdlib.h>
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#include <string.h>
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#include <unistd.h>
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#include "debug.h"
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#include "rtld.h"
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#include "libmap.h"
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#include "rtld_tls.h"
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#include "rtld_printf.h"
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#include "notes.h"
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#ifndef COMPAT_32BIT
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#define PATH_RTLD "/libexec/ld-elf.so.1"
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#else
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#define PATH_RTLD "/libexec/ld-elf32.so.1"
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#endif
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/* Types. */
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typedef void (*func_ptr_type)();
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typedef void * (*path_enum_proc) (const char *path, size_t len, void *arg);
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/*
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* Function declarations.
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*/
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static const char *basename(const char *);
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static void die(void) __dead2;
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static void digest_dynamic1(Obj_Entry *, int, const Elf_Dyn **,
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const Elf_Dyn **, const Elf_Dyn **);
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static void digest_dynamic2(Obj_Entry *, const Elf_Dyn *, const Elf_Dyn *,
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const Elf_Dyn *);
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static void digest_dynamic(Obj_Entry *, int);
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static Obj_Entry *digest_phdr(const Elf_Phdr *, int, caddr_t, const char *);
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static Obj_Entry *dlcheck(void *);
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static Obj_Entry *dlopen_object(const char *name, int fd, Obj_Entry *refobj,
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int lo_flags, int mode, RtldLockState *lockstate);
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static Obj_Entry *do_load_object(int, const char *, char *, struct stat *, int);
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static int do_search_info(const Obj_Entry *obj, int, struct dl_serinfo *);
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static bool donelist_check(DoneList *, const Obj_Entry *);
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static void errmsg_restore(char *);
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static char *errmsg_save(void);
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static void *fill_search_info(const char *, size_t, void *);
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static char *find_library(const char *, const Obj_Entry *);
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static const char *gethints(bool);
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static void init_dag(Obj_Entry *);
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static void init_rtld(caddr_t, Elf_Auxinfo **);
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static void initlist_add_neededs(Needed_Entry *, Objlist *);
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static void initlist_add_objects(Obj_Entry *, Obj_Entry **, Objlist *);
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static void linkmap_add(Obj_Entry *);
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static void linkmap_delete(Obj_Entry *);
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static void load_filtees(Obj_Entry *, int flags, RtldLockState *);
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static void unload_filtees(Obj_Entry *);
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static int load_needed_objects(Obj_Entry *, int);
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static int load_preload_objects(void);
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static Obj_Entry *load_object(const char *, int fd, const Obj_Entry *, int);
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static void map_stacks_exec(RtldLockState *);
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static Obj_Entry *obj_from_addr(const void *);
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static void objlist_call_fini(Objlist *, Obj_Entry *, RtldLockState *);
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static void objlist_call_init(Objlist *, RtldLockState *);
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static void objlist_clear(Objlist *);
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static Objlist_Entry *objlist_find(Objlist *, const Obj_Entry *);
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static void objlist_init(Objlist *);
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static void objlist_push_head(Objlist *, Obj_Entry *);
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static void objlist_push_tail(Objlist *, Obj_Entry *);
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static void objlist_put_after(Objlist *, Obj_Entry *, Obj_Entry *);
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static void objlist_remove(Objlist *, Obj_Entry *);
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static void *path_enumerate(const char *, path_enum_proc, void *);
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static int relocate_object_dag(Obj_Entry *root, bool bind_now,
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Obj_Entry *rtldobj, int flags, RtldLockState *lockstate);
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static int relocate_object(Obj_Entry *obj, bool bind_now, Obj_Entry *rtldobj,
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int flags, RtldLockState *lockstate);
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static int relocate_objects(Obj_Entry *, bool, Obj_Entry *, int,
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RtldLockState *);
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static int resolve_objects_ifunc(Obj_Entry *first, bool bind_now,
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int flags, RtldLockState *lockstate);
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static int rtld_dirname(const char *, char *);
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static int rtld_dirname_abs(const char *, char *);
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static void *rtld_dlopen(const char *name, int fd, int mode);
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static void rtld_exit(void);
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static char *search_library_path(const char *, const char *);
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static const void **get_program_var_addr(const char *, RtldLockState *);
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static void set_program_var(const char *, const void *);
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static int symlook_default(SymLook *, const Obj_Entry *refobj);
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static int symlook_global(SymLook *, DoneList *);
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static void symlook_init_from_req(SymLook *, const SymLook *);
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static int symlook_list(SymLook *, const Objlist *, DoneList *);
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static int symlook_needed(SymLook *, const Needed_Entry *, DoneList *);
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static int symlook_obj1_sysv(SymLook *, const Obj_Entry *);
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static int symlook_obj1_gnu(SymLook *, const Obj_Entry *);
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static void trace_loaded_objects(Obj_Entry *);
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static void unlink_object(Obj_Entry *);
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static void unload_object(Obj_Entry *);
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static void unref_dag(Obj_Entry *);
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static void ref_dag(Obj_Entry *);
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static char *origin_subst_one(char *, const char *, const char *, bool);
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static char *origin_subst(char *, const char *);
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static void preinit_main(void);
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static int rtld_verify_versions(const Objlist *);
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static int rtld_verify_object_versions(Obj_Entry *);
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static void object_add_name(Obj_Entry *, const char *);
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static int object_match_name(const Obj_Entry *, const char *);
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static void ld_utrace_log(int, void *, void *, size_t, int, const char *);
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static void rtld_fill_dl_phdr_info(const Obj_Entry *obj,
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struct dl_phdr_info *phdr_info);
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static uint32_t gnu_hash(const char *);
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static bool matched_symbol(SymLook *, const Obj_Entry *, Sym_Match_Result *,
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const unsigned long);
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void r_debug_state(struct r_debug *, struct link_map *) __noinline;
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void _r_debug_postinit(struct link_map *) __noinline;
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/*
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* Data declarations.
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*/
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static char *error_message; /* Message for dlerror(), or NULL */
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struct r_debug r_debug; /* for GDB; */
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static bool libmap_disable; /* Disable libmap */
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static bool ld_loadfltr; /* Immediate filters processing */
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static char *libmap_override; /* Maps to use in addition to libmap.conf */
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static bool trust; /* False for setuid and setgid programs */
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static bool dangerous_ld_env; /* True if environment variables have been
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used to affect the libraries loaded */
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static char *ld_bind_now; /* Environment variable for immediate binding */
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static char *ld_debug; /* Environment variable for debugging */
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static char *ld_library_path; /* Environment variable for search path */
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static char *ld_preload; /* Environment variable for libraries to
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load first */
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static char *ld_elf_hints_path; /* Environment variable for alternative hints path */
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static char *ld_tracing; /* Called from ldd to print libs */
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static char *ld_utrace; /* Use utrace() to log events. */
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static Obj_Entry *obj_list; /* Head of linked list of shared objects */
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static Obj_Entry **obj_tail; /* Link field of last object in list */
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static Obj_Entry *obj_main; /* The main program shared object */
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static Obj_Entry obj_rtld; /* The dynamic linker shared object */
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static unsigned int obj_count; /* Number of objects in obj_list */
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static unsigned int obj_loads; /* Number of objects in obj_list */
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static Objlist list_global = /* Objects dlopened with RTLD_GLOBAL */
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STAILQ_HEAD_INITIALIZER(list_global);
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static Objlist list_main = /* Objects loaded at program startup */
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STAILQ_HEAD_INITIALIZER(list_main);
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static Objlist list_fini = /* Objects needing fini() calls */
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STAILQ_HEAD_INITIALIZER(list_fini);
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Elf_Sym sym_zero; /* For resolving undefined weak refs. */
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#define GDB_STATE(s,m) r_debug.r_state = s; r_debug_state(&r_debug,m);
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extern Elf_Dyn _DYNAMIC;
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#pragma weak _DYNAMIC
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#ifndef RTLD_IS_DYNAMIC
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#define RTLD_IS_DYNAMIC() (&_DYNAMIC != NULL)
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#endif
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int osreldate, pagesize;
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long __stack_chk_guard[8] = {0, 0, 0, 0, 0, 0, 0, 0};
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static int stack_prot = PROT_READ | PROT_WRITE | RTLD_DEFAULT_STACK_EXEC;
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static int max_stack_flags;
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/*
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* Global declarations normally provided by crt1. The dynamic linker is
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* not built with crt1, so we have to provide them ourselves.
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*/
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char *__progname;
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char **environ;
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/*
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* Used to pass argc, argv to init functions.
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*/
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int main_argc;
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char **main_argv;
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/*
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* Globals to control TLS allocation.
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*/
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size_t tls_last_offset; /* Static TLS offset of last module */
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size_t tls_last_size; /* Static TLS size of last module */
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size_t tls_static_space; /* Static TLS space allocated */
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size_t tls_static_max_align;
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int tls_dtv_generation = 1; /* Used to detect when dtv size changes */
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int tls_max_index = 1; /* Largest module index allocated */
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bool ld_library_path_rpath = false;
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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 as 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 donelist_init(dlp) \
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((dlp)->objs = alloca(obj_count * sizeof (dlp)->objs[0]), \
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assert((dlp)->objs != NULL), \
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(dlp)->num_alloc = obj_count, \
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(dlp)->num_used = 0)
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#define UTRACE_DLOPEN_START 1
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#define UTRACE_DLOPEN_STOP 2
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#define UTRACE_DLCLOSE_START 3
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#define UTRACE_DLCLOSE_STOP 4
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#define UTRACE_LOAD_OBJECT 5
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#define UTRACE_UNLOAD_OBJECT 6
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#define UTRACE_ADD_RUNDEP 7
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#define UTRACE_PRELOAD_FINISHED 8
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#define UTRACE_INIT_CALL 9
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#define UTRACE_FINI_CALL 10
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struct utrace_rtld {
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char sig[4]; /* 'RTLD' */
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int event;
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void *handle;
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void *mapbase; /* Used for 'parent' and 'init/fini' */
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size_t mapsize;
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int refcnt; /* Used for 'mode' */
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char name[MAXPATHLEN];
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};
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#define LD_UTRACE(e, h, mb, ms, r, n) do { \
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if (ld_utrace != NULL) \
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ld_utrace_log(e, h, mb, ms, r, n); \
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} while (0)
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static void
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ld_utrace_log(int event, void *handle, void *mapbase, size_t mapsize,
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int refcnt, const char *name)
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{
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struct utrace_rtld ut;
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ut.sig[0] = 'R';
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ut.sig[1] = 'T';
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ut.sig[2] = 'L';
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ut.sig[3] = 'D';
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ut.event = event;
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ut.handle = handle;
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ut.mapbase = mapbase;
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ut.mapsize = mapsize;
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ut.refcnt = refcnt;
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bzero(ut.name, sizeof(ut.name));
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if (name)
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strlcpy(ut.name, name, sizeof(ut.name));
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utrace(&ut, sizeof(ut));
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}
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/*
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* Main entry point for dynamic linking. The first argument is the
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* stack pointer. The stack is expected to be laid out as described
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* in the SVR4 ABI specification, Intel 386 Processor Supplement.
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* Specifically, the stack pointer points to a word containing
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* ARGC. Following that in the stack is a null-terminated sequence
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* of pointers to argument strings. Then comes a null-terminated
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* sequence of pointers to environment strings. Finally, there is a
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* sequence of "auxiliary vector" entries.
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*
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* The second argument points to a place to store the dynamic linker's
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* exit procedure pointer and the third to a place to store the main
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* program's object.
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*
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* The return value is the main program's entry point.
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*/
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func_ptr_type
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_rtld(Elf_Addr *sp, func_ptr_type *exit_proc, Obj_Entry **objp)
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{
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Elf_Auxinfo *aux_info[AT_COUNT];
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int i;
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int argc;
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char **argv;
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char **env;
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Elf_Auxinfo *aux;
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Elf_Auxinfo *auxp;
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const char *argv0;
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Objlist_Entry *entry;
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Obj_Entry *obj;
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Obj_Entry **preload_tail;
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Obj_Entry *last_interposer;
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Objlist initlist;
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RtldLockState lockstate;
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char *library_path_rpath;
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int mib[2];
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size_t len;
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/*
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* On entry, the dynamic linker itself has not been relocated yet.
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* Be very careful not to reference any global data until after
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* init_rtld has returned. It is OK to reference file-scope statics
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* and string constants, and to call static and global functions.
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*/
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/* Find the auxiliary vector on the stack. */
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argc = *sp++;
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argv = (char **) sp;
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sp += argc + 1; /* Skip over arguments and NULL terminator */
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env = (char **) sp;
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while (*sp++ != 0) /* Skip over environment, and NULL terminator */
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;
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aux = (Elf_Auxinfo *) sp;
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/* Digest the auxiliary vector. */
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for (i = 0; i < AT_COUNT; i++)
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aux_info[i] = NULL;
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for (auxp = aux; auxp->a_type != AT_NULL; auxp++) {
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if (auxp->a_type < AT_COUNT)
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aux_info[auxp->a_type] = auxp;
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}
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/* Initialize and relocate ourselves. */
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assert(aux_info[AT_BASE] != NULL);
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init_rtld((caddr_t) aux_info[AT_BASE]->a_un.a_ptr, aux_info);
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__progname = obj_rtld.path;
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argv0 = argv[0] != NULL ? argv[0] : "(null)";
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environ = env;
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main_argc = argc;
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main_argv = argv;
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if (aux_info[AT_CANARY] != NULL &&
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aux_info[AT_CANARY]->a_un.a_ptr != NULL) {
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i = aux_info[AT_CANARYLEN]->a_un.a_val;
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if (i > sizeof(__stack_chk_guard))
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i = sizeof(__stack_chk_guard);
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memcpy(__stack_chk_guard, aux_info[AT_CANARY]->a_un.a_ptr, i);
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} else {
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mib[0] = CTL_KERN;
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mib[1] = KERN_ARND;
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len = sizeof(__stack_chk_guard);
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if (sysctl(mib, 2, __stack_chk_guard, &len, NULL, 0) == -1 ||
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len != sizeof(__stack_chk_guard)) {
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/* If sysctl was unsuccessful, use the "terminator canary". */
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((unsigned char *)(void *)__stack_chk_guard)[0] = 0;
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((unsigned char *)(void *)__stack_chk_guard)[1] = 0;
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((unsigned char *)(void *)__stack_chk_guard)[2] = '\n';
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((unsigned char *)(void *)__stack_chk_guard)[3] = 255;
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}
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}
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trust = !issetugid();
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ld_bind_now = getenv(LD_ "BIND_NOW");
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/*
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* If the process is tainted, then we un-set the dangerous environment
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* variables. The process will be marked as tainted until setuid(2)
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* is called. If any child process calls setuid(2) we do not want any
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* future processes to honor the potentially un-safe variables.
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*/
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if (!trust) {
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if (unsetenv(LD_ "PRELOAD") || unsetenv(LD_ "LIBMAP") ||
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unsetenv(LD_ "LIBRARY_PATH") || unsetenv(LD_ "LIBMAP_DISABLE") ||
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unsetenv(LD_ "DEBUG") || unsetenv(LD_ "ELF_HINTS_PATH") ||
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unsetenv(LD_ "LOADFLTR") || unsetenv(LD_ "LIBRARY_PATH_RPATH")) {
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_rtld_error("environment corrupt; aborting");
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die();
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}
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}
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ld_debug = getenv(LD_ "DEBUG");
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libmap_disable = getenv(LD_ "LIBMAP_DISABLE") != NULL;
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libmap_override = getenv(LD_ "LIBMAP");
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ld_library_path = getenv(LD_ "LIBRARY_PATH");
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ld_preload = getenv(LD_ "PRELOAD");
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ld_elf_hints_path = getenv(LD_ "ELF_HINTS_PATH");
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ld_loadfltr = getenv(LD_ "LOADFLTR") != NULL;
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library_path_rpath = getenv(LD_ "LIBRARY_PATH_RPATH");
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if (library_path_rpath != NULL) {
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if (library_path_rpath[0] == 'y' ||
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library_path_rpath[0] == 'Y' ||
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library_path_rpath[0] == '1')
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ld_library_path_rpath = true;
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else
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ld_library_path_rpath = false;
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}
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dangerous_ld_env = libmap_disable || (libmap_override != NULL) ||
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(ld_library_path != NULL) || (ld_preload != NULL) ||
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(ld_elf_hints_path != NULL) || ld_loadfltr;
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ld_tracing = getenv(LD_ "TRACE_LOADED_OBJECTS");
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ld_utrace = getenv(LD_ "UTRACE");
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|
|
if ((ld_elf_hints_path == NULL) || strlen(ld_elf_hints_path) == 0)
|
|
ld_elf_hints_path = _PATH_ELF_HINTS;
|
|
|
|
if (ld_debug != NULL && *ld_debug != '\0')
|
|
debug = 1;
|
|
dbg("%s is initialized, base address = %p", __progname,
|
|
(caddr_t) aux_info[AT_BASE]->a_un.a_ptr);
|
|
dbg("RTLD dynamic = %p", obj_rtld.dynamic);
|
|
dbg("RTLD pltgot = %p", obj_rtld.pltgot);
|
|
|
|
dbg("initializing thread locks");
|
|
lockdflt_init();
|
|
|
|
/*
|
|
* Load the main program, or process its program header if it is
|
|
* already loaded.
|
|
*/
|
|
if (aux_info[AT_EXECFD] != NULL) { /* Load the main program. */
|
|
int fd = aux_info[AT_EXECFD]->a_un.a_val;
|
|
dbg("loading main program");
|
|
obj_main = map_object(fd, argv0, NULL);
|
|
close(fd);
|
|
if (obj_main == NULL)
|
|
die();
|
|
max_stack_flags = obj->stack_flags;
|
|
} else { /* Main program already loaded. */
|
|
const Elf_Phdr *phdr;
|
|
int phnum;
|
|
caddr_t entry;
|
|
|
|
dbg("processing main program's program header");
|
|
assert(aux_info[AT_PHDR] != NULL);
|
|
phdr = (const Elf_Phdr *) aux_info[AT_PHDR]->a_un.a_ptr;
|
|
assert(aux_info[AT_PHNUM] != NULL);
|
|
phnum = aux_info[AT_PHNUM]->a_un.a_val;
|
|
assert(aux_info[AT_PHENT] != NULL);
|
|
assert(aux_info[AT_PHENT]->a_un.a_val == sizeof(Elf_Phdr));
|
|
assert(aux_info[AT_ENTRY] != NULL);
|
|
entry = (caddr_t) aux_info[AT_ENTRY]->a_un.a_ptr;
|
|
if ((obj_main = digest_phdr(phdr, phnum, entry, argv0)) == NULL)
|
|
die();
|
|
}
|
|
|
|
if (aux_info[AT_EXECPATH] != 0) {
|
|
char *kexecpath;
|
|
char buf[MAXPATHLEN];
|
|
|
|
kexecpath = aux_info[AT_EXECPATH]->a_un.a_ptr;
|
|
dbg("AT_EXECPATH %p %s", kexecpath, kexecpath);
|
|
if (kexecpath[0] == '/')
|
|
obj_main->path = kexecpath;
|
|
else if (getcwd(buf, sizeof(buf)) == NULL ||
|
|
strlcat(buf, "/", sizeof(buf)) >= sizeof(buf) ||
|
|
strlcat(buf, kexecpath, sizeof(buf)) >= sizeof(buf))
|
|
obj_main->path = xstrdup(argv0);
|
|
else
|
|
obj_main->path = xstrdup(buf);
|
|
} else {
|
|
dbg("No AT_EXECPATH");
|
|
obj_main->path = xstrdup(argv0);
|
|
}
|
|
dbg("obj_main path %s", obj_main->path);
|
|
obj_main->mainprog = true;
|
|
|
|
if (aux_info[AT_STACKPROT] != NULL &&
|
|
aux_info[AT_STACKPROT]->a_un.a_val != 0)
|
|
stack_prot = aux_info[AT_STACKPROT]->a_un.a_val;
|
|
|
|
/*
|
|
* Get the actual dynamic linker pathname from the executable if
|
|
* possible. (It should always be possible.) That ensures that
|
|
* gdb will find the right dynamic linker even if a non-standard
|
|
* one is being used.
|
|
*/
|
|
if (obj_main->interp != NULL &&
|
|
strcmp(obj_main->interp, obj_rtld.path) != 0) {
|
|
free(obj_rtld.path);
|
|
obj_rtld.path = xstrdup(obj_main->interp);
|
|
__progname = obj_rtld.path;
|
|
}
|
|
|
|
digest_dynamic(obj_main, 0);
|
|
dbg("%s valid_hash_sysv %d valid_hash_gnu %d dynsymcount %d",
|
|
obj_main->path, obj_main->valid_hash_sysv, obj_main->valid_hash_gnu,
|
|
obj_main->dynsymcount);
|
|
|
|
linkmap_add(obj_main);
|
|
linkmap_add(&obj_rtld);
|
|
|
|
/* Link the main program into the list of objects. */
|
|
*obj_tail = obj_main;
|
|
obj_tail = &obj_main->next;
|
|
obj_count++;
|
|
obj_loads++;
|
|
|
|
/* Initialize a fake symbol for resolving undefined weak references. */
|
|
sym_zero.st_info = ELF_ST_INFO(STB_GLOBAL, STT_NOTYPE);
|
|
sym_zero.st_shndx = SHN_UNDEF;
|
|
sym_zero.st_value = -(uintptr_t)obj_main->relocbase;
|
|
|
|
if (!libmap_disable)
|
|
libmap_disable = (bool)lm_init(libmap_override);
|
|
|
|
dbg("loading LD_PRELOAD libraries");
|
|
if (load_preload_objects() == -1)
|
|
die();
|
|
preload_tail = obj_tail;
|
|
|
|
dbg("loading needed objects");
|
|
if (load_needed_objects(obj_main, 0) == -1)
|
|
die();
|
|
|
|
/* Make a list of all objects loaded at startup. */
|
|
last_interposer = obj_main;
|
|
for (obj = obj_list; obj != NULL; obj = obj->next) {
|
|
if (obj->z_interpose && obj != obj_main) {
|
|
objlist_put_after(&list_main, last_interposer, obj);
|
|
last_interposer = obj;
|
|
} else {
|
|
objlist_push_tail(&list_main, obj);
|
|
}
|
|
obj->refcount++;
|
|
}
|
|
|
|
dbg("checking for required versions");
|
|
if (rtld_verify_versions(&list_main) == -1 && !ld_tracing)
|
|
die();
|
|
|
|
if (ld_tracing) { /* We're done */
|
|
trace_loaded_objects(obj_main);
|
|
exit(0);
|
|
}
|
|
|
|
if (getenv(LD_ "DUMP_REL_PRE") != NULL) {
|
|
dump_relocations(obj_main);
|
|
exit (0);
|
|
}
|
|
|
|
/*
|
|
* Processing tls relocations requires having the tls offsets
|
|
* initialized. Prepare offsets before starting initial
|
|
* relocation processing.
|
|
*/
|
|
dbg("initializing initial thread local storage offsets");
|
|
STAILQ_FOREACH(entry, &list_main, link) {
|
|
/*
|
|
* Allocate all the initial objects out of the static TLS
|
|
* block even if they didn't ask for it.
|
|
*/
|
|
allocate_tls_offset(entry->obj);
|
|
}
|
|
|
|
if (relocate_objects(obj_main,
|
|
ld_bind_now != NULL && *ld_bind_now != '\0',
|
|
&obj_rtld, SYMLOOK_EARLY, NULL) == -1)
|
|
die();
|
|
|
|
dbg("doing copy relocations");
|
|
if (do_copy_relocations(obj_main) == -1)
|
|
die();
|
|
|
|
if (getenv(LD_ "DUMP_REL_POST") != NULL) {
|
|
dump_relocations(obj_main);
|
|
exit (0);
|
|
}
|
|
|
|
/*
|
|
* Setup TLS for main thread. This must be done after the
|
|
* relocations are processed, since tls initialization section
|
|
* might be the subject for relocations.
|
|
*/
|
|
dbg("initializing initial thread local storage");
|
|
allocate_initial_tls(obj_list);
|
|
|
|
dbg("initializing key program variables");
|
|
set_program_var("__progname", argv[0] != NULL ? basename(argv[0]) : "");
|
|
set_program_var("environ", env);
|
|
set_program_var("__elf_aux_vector", aux);
|
|
|
|
/* Make a list of init functions to call. */
|
|
objlist_init(&initlist);
|
|
initlist_add_objects(obj_list, preload_tail, &initlist);
|
|
|
|
r_debug_state(NULL, &obj_main->linkmap); /* say hello to gdb! */
|
|
|
|
map_stacks_exec(NULL);
|
|
|
|
dbg("resolving ifuncs");
|
|
if (resolve_objects_ifunc(obj_main,
|
|
ld_bind_now != NULL && *ld_bind_now != '\0', SYMLOOK_EARLY,
|
|
NULL) == -1)
|
|
die();
|
|
|
|
if (!obj_main->crt_no_init) {
|
|
/*
|
|
* Make sure we don't call the main program's init and fini
|
|
* functions for binaries linked with old crt1 which calls
|
|
* _init itself.
|
|
*/
|
|
obj_main->init = obj_main->fini = (Elf_Addr)NULL;
|
|
obj_main->preinit_array = obj_main->init_array =
|
|
obj_main->fini_array = (Elf_Addr)NULL;
|
|
}
|
|
|
|
wlock_acquire(rtld_bind_lock, &lockstate);
|
|
if (obj_main->crt_no_init)
|
|
preinit_main();
|
|
objlist_call_init(&initlist, &lockstate);
|
|
_r_debug_postinit(&obj_main->linkmap);
|
|
objlist_clear(&initlist);
|
|
dbg("loading filtees");
|
|
for (obj = obj_list->next; obj != NULL; obj = obj->next) {
|
|
if (ld_loadfltr || obj->z_loadfltr)
|
|
load_filtees(obj, 0, &lockstate);
|
|
}
|
|
lock_release(rtld_bind_lock, &lockstate);
|
|
|
|
dbg("transferring control to program entry point = %p", obj_main->entry);
|
|
|
|
/* Return the exit procedure and the program entry point. */
|
|
*exit_proc = rtld_exit;
|
|
*objp = obj_main;
|
|
return (func_ptr_type) obj_main->entry;
|
|
}
|
|
|
|
void *
|
|
rtld_resolve_ifunc(const Obj_Entry *obj, const Elf_Sym *def)
|
|
{
|
|
void *ptr;
|
|
Elf_Addr target;
|
|
|
|
ptr = (void *)make_function_pointer(def, obj);
|
|
target = ((Elf_Addr (*)(void))ptr)();
|
|
return ((void *)target);
|
|
}
|
|
|
|
Elf_Addr
|
|
_rtld_bind(Obj_Entry *obj, Elf_Size reloff)
|
|
{
|
|
const Elf_Rel *rel;
|
|
const Elf_Sym *def;
|
|
const Obj_Entry *defobj;
|
|
Elf_Addr *where;
|
|
Elf_Addr target;
|
|
RtldLockState lockstate;
|
|
|
|
rlock_acquire(rtld_bind_lock, &lockstate);
|
|
if (sigsetjmp(lockstate.env, 0) != 0)
|
|
lock_upgrade(rtld_bind_lock, &lockstate);
|
|
if (obj->pltrel)
|
|
rel = (const Elf_Rel *) ((caddr_t) obj->pltrel + reloff);
|
|
else
|
|
rel = (const Elf_Rel *) ((caddr_t) obj->pltrela + reloff);
|
|
|
|
where = (Elf_Addr *) (obj->relocbase + rel->r_offset);
|
|
def = find_symdef(ELF_R_SYM(rel->r_info), obj, &defobj, true, NULL,
|
|
&lockstate);
|
|
if (def == NULL)
|
|
die();
|
|
if (ELF_ST_TYPE(def->st_info) == STT_GNU_IFUNC)
|
|
target = (Elf_Addr)rtld_resolve_ifunc(defobj, def);
|
|
else
|
|
target = (Elf_Addr)(defobj->relocbase + def->st_value);
|
|
|
|
dbg("\"%s\" in \"%s\" ==> %p in \"%s\"",
|
|
defobj->strtab + def->st_name, basename(obj->path),
|
|
(void *)target, basename(defobj->path));
|
|
|
|
/*
|
|
* Write the new contents for the jmpslot. Note that depending on
|
|
* architecture, the value which we need to return back to the
|
|
* lazy binding trampoline may or may not be the target
|
|
* address. The value returned from reloc_jmpslot() is the value
|
|
* that the trampoline needs.
|
|
*/
|
|
target = reloc_jmpslot(where, target, defobj, obj, rel);
|
|
lock_release(rtld_bind_lock, &lockstate);
|
|
return target;
|
|
}
|
|
|
|
/*
|
|
* Error reporting function. Use it like printf. If formats the message
|
|
* into a buffer, and sets things up so that the next call to dlerror()
|
|
* will return the message.
|
|
*/
|
|
void
|
|
_rtld_error(const char *fmt, ...)
|
|
{
|
|
static char buf[512];
|
|
va_list ap;
|
|
|
|
va_start(ap, fmt);
|
|
rtld_vsnprintf(buf, sizeof buf, fmt, ap);
|
|
error_message = buf;
|
|
va_end(ap);
|
|
}
|
|
|
|
/*
|
|
* Return a dynamically-allocated copy of the current error message, if any.
|
|
*/
|
|
static char *
|
|
errmsg_save(void)
|
|
{
|
|
return error_message == NULL ? NULL : xstrdup(error_message);
|
|
}
|
|
|
|
/*
|
|
* Restore the current error message from a copy which was previously saved
|
|
* by errmsg_save(). The copy is freed.
|
|
*/
|
|
static void
|
|
errmsg_restore(char *saved_msg)
|
|
{
|
|
if (saved_msg == NULL)
|
|
error_message = NULL;
|
|
else {
|
|
_rtld_error("%s", saved_msg);
|
|
free(saved_msg);
|
|
}
|
|
}
|
|
|
|
static const char *
|
|
basename(const char *name)
|
|
{
|
|
const char *p = strrchr(name, '/');
|
|
return p != NULL ? p + 1 : name;
|
|
}
|
|
|
|
static struct utsname uts;
|
|
|
|
static char *
|
|
origin_subst_one(char *real, const char *kw, const char *subst,
|
|
bool may_free)
|
|
{
|
|
char *p, *p1, *res, *resp;
|
|
int subst_len, kw_len, subst_count, old_len, new_len;
|
|
|
|
kw_len = strlen(kw);
|
|
|
|
/*
|
|
* First, count the number of the keyword occurences, to
|
|
* preallocate the final string.
|
|
*/
|
|
for (p = real, subst_count = 0;; p = p1 + kw_len, subst_count++) {
|
|
p1 = strstr(p, kw);
|
|
if (p1 == NULL)
|
|
break;
|
|
}
|
|
|
|
/*
|
|
* If the keyword is not found, just return.
|
|
*/
|
|
if (subst_count == 0)
|
|
return (may_free ? real : xstrdup(real));
|
|
|
|
/*
|
|
* There is indeed something to substitute. Calculate the
|
|
* length of the resulting string, and allocate it.
|
|
*/
|
|
subst_len = strlen(subst);
|
|
old_len = strlen(real);
|
|
new_len = old_len + (subst_len - kw_len) * subst_count;
|
|
res = xmalloc(new_len + 1);
|
|
|
|
/*
|
|
* Now, execute the substitution loop.
|
|
*/
|
|
for (p = real, resp = res, *resp = '\0';;) {
|
|
p1 = strstr(p, kw);
|
|
if (p1 != NULL) {
|
|
/* Copy the prefix before keyword. */
|
|
memcpy(resp, p, p1 - p);
|
|
resp += p1 - p;
|
|
/* Keyword replacement. */
|
|
memcpy(resp, subst, subst_len);
|
|
resp += subst_len;
|
|
*resp = '\0';
|
|
p = p1 + kw_len;
|
|
} else
|
|
break;
|
|
}
|
|
|
|
/* Copy to the end of string and finish. */
|
|
strcat(resp, p);
|
|
if (may_free)
|
|
free(real);
|
|
return (res);
|
|
}
|
|
|
|
static char *
|
|
origin_subst(char *real, const char *origin_path)
|
|
{
|
|
char *res1, *res2, *res3, *res4;
|
|
|
|
if (uts.sysname[0] == '\0') {
|
|
if (uname(&uts) != 0) {
|
|
_rtld_error("utsname failed: %d", errno);
|
|
return (NULL);
|
|
}
|
|
}
|
|
res1 = origin_subst_one(real, "$ORIGIN", origin_path, false);
|
|
res2 = origin_subst_one(res1, "$OSNAME", uts.sysname, true);
|
|
res3 = origin_subst_one(res2, "$OSREL", uts.release, true);
|
|
res4 = origin_subst_one(res3, "$PLATFORM", uts.machine, true);
|
|
return (res4);
|
|
}
|
|
|
|
static void
|
|
die(void)
|
|
{
|
|
const char *msg = dlerror();
|
|
|
|
if (msg == NULL)
|
|
msg = "Fatal error";
|
|
rtld_fdputstr(STDERR_FILENO, msg);
|
|
rtld_fdputchar(STDERR_FILENO, '\n');
|
|
_exit(1);
|
|
}
|
|
|
|
/*
|
|
* Process a shared object's DYNAMIC section, and save the important
|
|
* information in its Obj_Entry structure.
|
|
*/
|
|
static void
|
|
digest_dynamic1(Obj_Entry *obj, int early, const Elf_Dyn **dyn_rpath,
|
|
const Elf_Dyn **dyn_soname, const Elf_Dyn **dyn_runpath)
|
|
{
|
|
const Elf_Dyn *dynp;
|
|
Needed_Entry **needed_tail = &obj->needed;
|
|
Needed_Entry **needed_filtees_tail = &obj->needed_filtees;
|
|
Needed_Entry **needed_aux_filtees_tail = &obj->needed_aux_filtees;
|
|
const Elf_Hashelt *hashtab;
|
|
const Elf32_Word *hashval;
|
|
Elf32_Word bkt, nmaskwords;
|
|
int bloom_size32;
|
|
bool nmw_power2;
|
|
int plttype = DT_REL;
|
|
|
|
*dyn_rpath = NULL;
|
|
*dyn_soname = NULL;
|
|
*dyn_runpath = NULL;
|
|
|
|
obj->bind_now = false;
|
|
for (dynp = obj->dynamic; dynp->d_tag != DT_NULL; dynp++) {
|
|
switch (dynp->d_tag) {
|
|
|
|
case DT_REL:
|
|
obj->rel = (const Elf_Rel *) (obj->relocbase + dynp->d_un.d_ptr);
|
|
break;
|
|
|
|
case DT_RELSZ:
|
|
obj->relsize = dynp->d_un.d_val;
|
|
break;
|
|
|
|
case DT_RELENT:
|
|
assert(dynp->d_un.d_val == sizeof(Elf_Rel));
|
|
break;
|
|
|
|
case DT_JMPREL:
|
|
obj->pltrel = (const Elf_Rel *)
|
|
(obj->relocbase + dynp->d_un.d_ptr);
|
|
break;
|
|
|
|
case DT_PLTRELSZ:
|
|
obj->pltrelsize = dynp->d_un.d_val;
|
|
break;
|
|
|
|
case DT_RELA:
|
|
obj->rela = (const Elf_Rela *) (obj->relocbase + dynp->d_un.d_ptr);
|
|
break;
|
|
|
|
case DT_RELASZ:
|
|
obj->relasize = dynp->d_un.d_val;
|
|
break;
|
|
|
|
case DT_RELAENT:
|
|
assert(dynp->d_un.d_val == sizeof(Elf_Rela));
|
|
break;
|
|
|
|
case DT_PLTREL:
|
|
plttype = dynp->d_un.d_val;
|
|
assert(dynp->d_un.d_val == DT_REL || plttype == DT_RELA);
|
|
break;
|
|
|
|
case DT_SYMTAB:
|
|
obj->symtab = (const Elf_Sym *)
|
|
(obj->relocbase + dynp->d_un.d_ptr);
|
|
break;
|
|
|
|
case DT_SYMENT:
|
|
assert(dynp->d_un.d_val == sizeof(Elf_Sym));
|
|
break;
|
|
|
|
case DT_STRTAB:
|
|
obj->strtab = (const char *) (obj->relocbase + dynp->d_un.d_ptr);
|
|
break;
|
|
|
|
case DT_STRSZ:
|
|
obj->strsize = dynp->d_un.d_val;
|
|
break;
|
|
|
|
case DT_VERNEED:
|
|
obj->verneed = (const Elf_Verneed *) (obj->relocbase +
|
|
dynp->d_un.d_val);
|
|
break;
|
|
|
|
case DT_VERNEEDNUM:
|
|
obj->verneednum = dynp->d_un.d_val;
|
|
break;
|
|
|
|
case DT_VERDEF:
|
|
obj->verdef = (const Elf_Verdef *) (obj->relocbase +
|
|
dynp->d_un.d_val);
|
|
break;
|
|
|
|
case DT_VERDEFNUM:
|
|
obj->verdefnum = dynp->d_un.d_val;
|
|
break;
|
|
|
|
case DT_VERSYM:
|
|
obj->versyms = (const Elf_Versym *)(obj->relocbase +
|
|
dynp->d_un.d_val);
|
|
break;
|
|
|
|
case DT_HASH:
|
|
{
|
|
hashtab = (const Elf_Hashelt *)(obj->relocbase +
|
|
dynp->d_un.d_ptr);
|
|
obj->nbuckets = hashtab[0];
|
|
obj->nchains = hashtab[1];
|
|
obj->buckets = hashtab + 2;
|
|
obj->chains = obj->buckets + obj->nbuckets;
|
|
obj->valid_hash_sysv = obj->nbuckets > 0 && obj->nchains > 0 &&
|
|
obj->buckets != NULL;
|
|
}
|
|
break;
|
|
|
|
case DT_GNU_HASH:
|
|
{
|
|
hashtab = (const Elf_Hashelt *)(obj->relocbase +
|
|
dynp->d_un.d_ptr);
|
|
obj->nbuckets_gnu = hashtab[0];
|
|
obj->symndx_gnu = hashtab[1];
|
|
nmaskwords = hashtab[2];
|
|
bloom_size32 = (__ELF_WORD_SIZE / 32) * nmaskwords;
|
|
/* Number of bitmask words is required to be power of 2 */
|
|
nmw_power2 = ((nmaskwords & (nmaskwords - 1)) == 0);
|
|
obj->maskwords_bm_gnu = nmaskwords - 1;
|
|
obj->shift2_gnu = hashtab[3];
|
|
obj->bloom_gnu = (Elf_Addr *) (hashtab + 4);
|
|
obj->buckets_gnu = hashtab + 4 + bloom_size32;
|
|
obj->chain_zero_gnu = obj->buckets_gnu + obj->nbuckets_gnu -
|
|
obj->symndx_gnu;
|
|
obj->valid_hash_gnu = nmw_power2 && obj->nbuckets_gnu > 0 &&
|
|
obj->buckets_gnu != NULL;
|
|
}
|
|
break;
|
|
|
|
case DT_NEEDED:
|
|
if (!obj->rtld) {
|
|
Needed_Entry *nep = NEW(Needed_Entry);
|
|
nep->name = dynp->d_un.d_val;
|
|
nep->obj = NULL;
|
|
nep->next = NULL;
|
|
|
|
*needed_tail = nep;
|
|
needed_tail = &nep->next;
|
|
}
|
|
break;
|
|
|
|
case DT_FILTER:
|
|
if (!obj->rtld) {
|
|
Needed_Entry *nep = NEW(Needed_Entry);
|
|
nep->name = dynp->d_un.d_val;
|
|
nep->obj = NULL;
|
|
nep->next = NULL;
|
|
|
|
*needed_filtees_tail = nep;
|
|
needed_filtees_tail = &nep->next;
|
|
}
|
|
break;
|
|
|
|
case DT_AUXILIARY:
|
|
if (!obj->rtld) {
|
|
Needed_Entry *nep = NEW(Needed_Entry);
|
|
nep->name = dynp->d_un.d_val;
|
|
nep->obj = NULL;
|
|
nep->next = NULL;
|
|
|
|
*needed_aux_filtees_tail = nep;
|
|
needed_aux_filtees_tail = &nep->next;
|
|
}
|
|
break;
|
|
|
|
case DT_PLTGOT:
|
|
obj->pltgot = (Elf_Addr *) (obj->relocbase + dynp->d_un.d_ptr);
|
|
break;
|
|
|
|
case DT_TEXTREL:
|
|
obj->textrel = true;
|
|
break;
|
|
|
|
case DT_SYMBOLIC:
|
|
obj->symbolic = true;
|
|
break;
|
|
|
|
case DT_RPATH:
|
|
/*
|
|
* We have to wait until later to process this, because we
|
|
* might not have gotten the address of the string table yet.
|
|
*/
|
|
*dyn_rpath = dynp;
|
|
break;
|
|
|
|
case DT_SONAME:
|
|
*dyn_soname = dynp;
|
|
break;
|
|
|
|
case DT_RUNPATH:
|
|
*dyn_runpath = dynp;
|
|
break;
|
|
|
|
case DT_INIT:
|
|
obj->init = (Elf_Addr) (obj->relocbase + dynp->d_un.d_ptr);
|
|
break;
|
|
|
|
case DT_PREINIT_ARRAY:
|
|
obj->preinit_array = (Elf_Addr)(obj->relocbase + dynp->d_un.d_ptr);
|
|
break;
|
|
|
|
case DT_PREINIT_ARRAYSZ:
|
|
obj->preinit_array_num = dynp->d_un.d_val / sizeof(Elf_Addr);
|
|
break;
|
|
|
|
case DT_INIT_ARRAY:
|
|
obj->init_array = (Elf_Addr)(obj->relocbase + dynp->d_un.d_ptr);
|
|
break;
|
|
|
|
case DT_INIT_ARRAYSZ:
|
|
obj->init_array_num = dynp->d_un.d_val / sizeof(Elf_Addr);
|
|
break;
|
|
|
|
case DT_FINI:
|
|
obj->fini = (Elf_Addr) (obj->relocbase + dynp->d_un.d_ptr);
|
|
break;
|
|
|
|
case DT_FINI_ARRAY:
|
|
obj->fini_array = (Elf_Addr)(obj->relocbase + dynp->d_un.d_ptr);
|
|
break;
|
|
|
|
case DT_FINI_ARRAYSZ:
|
|
obj->fini_array_num = dynp->d_un.d_val / sizeof(Elf_Addr);
|
|
break;
|
|
|
|
/*
|
|
* Don't process DT_DEBUG on MIPS as the dynamic section
|
|
* is mapped read-only. DT_MIPS_RLD_MAP is used instead.
|
|
*/
|
|
|
|
#ifndef __mips__
|
|
case DT_DEBUG:
|
|
/* XXX - not implemented yet */
|
|
if (!early)
|
|
dbg("Filling in DT_DEBUG entry");
|
|
((Elf_Dyn*)dynp)->d_un.d_ptr = (Elf_Addr) &r_debug;
|
|
break;
|
|
#endif
|
|
|
|
case DT_FLAGS:
|
|
if ((dynp->d_un.d_val & DF_ORIGIN) && trust)
|
|
obj->z_origin = true;
|
|
if (dynp->d_un.d_val & DF_SYMBOLIC)
|
|
obj->symbolic = true;
|
|
if (dynp->d_un.d_val & DF_TEXTREL)
|
|
obj->textrel = true;
|
|
if (dynp->d_un.d_val & DF_BIND_NOW)
|
|
obj->bind_now = true;
|
|
/*if (dynp->d_un.d_val & DF_STATIC_TLS)
|
|
;*/
|
|
break;
|
|
#ifdef __mips__
|
|
case DT_MIPS_LOCAL_GOTNO:
|
|
obj->local_gotno = dynp->d_un.d_val;
|
|
break;
|
|
|
|
case DT_MIPS_SYMTABNO:
|
|
obj->symtabno = dynp->d_un.d_val;
|
|
break;
|
|
|
|
case DT_MIPS_GOTSYM:
|
|
obj->gotsym = dynp->d_un.d_val;
|
|
break;
|
|
|
|
case DT_MIPS_RLD_MAP:
|
|
*((Elf_Addr *)(dynp->d_un.d_ptr)) = (Elf_Addr) &r_debug;
|
|
break;
|
|
#endif
|
|
|
|
case DT_FLAGS_1:
|
|
if (dynp->d_un.d_val & DF_1_NOOPEN)
|
|
obj->z_noopen = true;
|
|
if ((dynp->d_un.d_val & DF_1_ORIGIN) && trust)
|
|
obj->z_origin = true;
|
|
/*if (dynp->d_un.d_val & DF_1_GLOBAL)
|
|
XXX ;*/
|
|
if (dynp->d_un.d_val & DF_1_BIND_NOW)
|
|
obj->bind_now = true;
|
|
if (dynp->d_un.d_val & DF_1_NODELETE)
|
|
obj->z_nodelete = true;
|
|
if (dynp->d_un.d_val & DF_1_LOADFLTR)
|
|
obj->z_loadfltr = true;
|
|
if (dynp->d_un.d_val & DF_1_INTERPOSE)
|
|
obj->z_interpose = true;
|
|
if (dynp->d_un.d_val & DF_1_NODEFLIB)
|
|
obj->z_nodeflib = true;
|
|
break;
|
|
|
|
default:
|
|
if (!early) {
|
|
dbg("Ignoring d_tag %ld = %#lx", (long)dynp->d_tag,
|
|
(long)dynp->d_tag);
|
|
}
|
|
break;
|
|
}
|
|
}
|
|
|
|
obj->traced = false;
|
|
|
|
if (plttype == DT_RELA) {
|
|
obj->pltrela = (const Elf_Rela *) obj->pltrel;
|
|
obj->pltrel = NULL;
|
|
obj->pltrelasize = obj->pltrelsize;
|
|
obj->pltrelsize = 0;
|
|
}
|
|
|
|
/* Determine size of dynsym table (equal to nchains of sysv hash) */
|
|
if (obj->valid_hash_sysv)
|
|
obj->dynsymcount = obj->nchains;
|
|
else if (obj->valid_hash_gnu) {
|
|
obj->dynsymcount = 0;
|
|
for (bkt = 0; bkt < obj->nbuckets_gnu; bkt++) {
|
|
if (obj->buckets_gnu[bkt] == 0)
|
|
continue;
|
|
hashval = &obj->chain_zero_gnu[obj->buckets_gnu[bkt]];
|
|
do
|
|
obj->dynsymcount++;
|
|
while ((*hashval++ & 1u) == 0);
|
|
}
|
|
obj->dynsymcount += obj->symndx_gnu;
|
|
}
|
|
}
|
|
|
|
static void
|
|
digest_dynamic2(Obj_Entry *obj, const Elf_Dyn *dyn_rpath,
|
|
const Elf_Dyn *dyn_soname, const Elf_Dyn *dyn_runpath)
|
|
{
|
|
|
|
if (obj->z_origin && obj->origin_path == NULL) {
|
|
obj->origin_path = xmalloc(PATH_MAX);
|
|
if (rtld_dirname_abs(obj->path, obj->origin_path) == -1)
|
|
die();
|
|
}
|
|
|
|
if (dyn_runpath != NULL) {
|
|
obj->runpath = (char *)obj->strtab + dyn_runpath->d_un.d_val;
|
|
if (obj->z_origin)
|
|
obj->runpath = origin_subst(obj->runpath, obj->origin_path);
|
|
}
|
|
else if (dyn_rpath != NULL) {
|
|
obj->rpath = (char *)obj->strtab + dyn_rpath->d_un.d_val;
|
|
if (obj->z_origin)
|
|
obj->rpath = origin_subst(obj->rpath, obj->origin_path);
|
|
}
|
|
|
|
if (dyn_soname != NULL)
|
|
object_add_name(obj, obj->strtab + dyn_soname->d_un.d_val);
|
|
}
|
|
|
|
static void
|
|
digest_dynamic(Obj_Entry *obj, int early)
|
|
{
|
|
const Elf_Dyn *dyn_rpath;
|
|
const Elf_Dyn *dyn_soname;
|
|
const Elf_Dyn *dyn_runpath;
|
|
|
|
digest_dynamic1(obj, early, &dyn_rpath, &dyn_soname, &dyn_runpath);
|
|
digest_dynamic2(obj, dyn_rpath, dyn_soname, dyn_runpath);
|
|
}
|
|
|
|
/*
|
|
* Process a shared object's program header. This is used only for the
|
|
* main program, when the kernel has already loaded the main program
|
|
* into memory before calling the dynamic linker. It creates and
|
|
* returns an Obj_Entry structure.
|
|
*/
|
|
static Obj_Entry *
|
|
digest_phdr(const Elf_Phdr *phdr, int phnum, caddr_t entry, const char *path)
|
|
{
|
|
Obj_Entry *obj;
|
|
const Elf_Phdr *phlimit = phdr + phnum;
|
|
const Elf_Phdr *ph;
|
|
Elf_Addr note_start, note_end;
|
|
int nsegs = 0;
|
|
|
|
obj = obj_new();
|
|
for (ph = phdr; ph < phlimit; ph++) {
|
|
if (ph->p_type != PT_PHDR)
|
|
continue;
|
|
|
|
obj->phdr = phdr;
|
|
obj->phsize = ph->p_memsz;
|
|
obj->relocbase = (caddr_t)phdr - ph->p_vaddr;
|
|
break;
|
|
}
|
|
|
|
obj->stack_flags = PF_X | PF_R | PF_W;
|
|
|
|
for (ph = phdr; ph < phlimit; ph++) {
|
|
switch (ph->p_type) {
|
|
|
|
case PT_INTERP:
|
|
obj->interp = (const char *)(ph->p_vaddr + obj->relocbase);
|
|
break;
|
|
|
|
case PT_LOAD:
|
|
if (nsegs == 0) { /* First load segment */
|
|
obj->vaddrbase = trunc_page(ph->p_vaddr);
|
|
obj->mapbase = obj->vaddrbase + obj->relocbase;
|
|
obj->textsize = round_page(ph->p_vaddr + ph->p_memsz) -
|
|
obj->vaddrbase;
|
|
} else { /* Last load segment */
|
|
obj->mapsize = round_page(ph->p_vaddr + ph->p_memsz) -
|
|
obj->vaddrbase;
|
|
}
|
|
nsegs++;
|
|
break;
|
|
|
|
case PT_DYNAMIC:
|
|
obj->dynamic = (const Elf_Dyn *)(ph->p_vaddr + obj->relocbase);
|
|
break;
|
|
|
|
case PT_TLS:
|
|
obj->tlsindex = 1;
|
|
obj->tlssize = ph->p_memsz;
|
|
obj->tlsalign = ph->p_align;
|
|
obj->tlsinitsize = ph->p_filesz;
|
|
obj->tlsinit = (void*)(ph->p_vaddr + obj->relocbase);
|
|
break;
|
|
|
|
case PT_GNU_STACK:
|
|
obj->stack_flags = ph->p_flags;
|
|
break;
|
|
|
|
case PT_GNU_RELRO:
|
|
obj->relro_page = obj->relocbase + trunc_page(ph->p_vaddr);
|
|
obj->relro_size = round_page(ph->p_memsz);
|
|
break;
|
|
|
|
case PT_NOTE:
|
|
note_start = (Elf_Addr)obj->relocbase + ph->p_vaddr;
|
|
note_end = note_start + ph->p_filesz;
|
|
digest_notes(obj, note_start, note_end);
|
|
break;
|
|
}
|
|
}
|
|
if (nsegs < 1) {
|
|
_rtld_error("%s: too few PT_LOAD segments", path);
|
|
return NULL;
|
|
}
|
|
|
|
obj->entry = entry;
|
|
return obj;
|
|
}
|
|
|
|
void
|
|
digest_notes(Obj_Entry *obj, Elf_Addr note_start, Elf_Addr note_end)
|
|
{
|
|
const Elf_Note *note;
|
|
const char *note_name;
|
|
uintptr_t p;
|
|
|
|
for (note = (const Elf_Note *)note_start; (Elf_Addr)note < note_end;
|
|
note = (const Elf_Note *)((const char *)(note + 1) +
|
|
roundup2(note->n_namesz, sizeof(Elf32_Addr)) +
|
|
roundup2(note->n_descsz, sizeof(Elf32_Addr)))) {
|
|
if (note->n_namesz != sizeof(NOTE_FREEBSD_VENDOR) ||
|
|
note->n_descsz != sizeof(int32_t))
|
|
continue;
|
|
if (note->n_type != ABI_NOTETYPE &&
|
|
note->n_type != CRT_NOINIT_NOTETYPE)
|
|
continue;
|
|
note_name = (const char *)(note + 1);
|
|
if (strncmp(NOTE_FREEBSD_VENDOR, note_name,
|
|
sizeof(NOTE_FREEBSD_VENDOR)) != 0)
|
|
continue;
|
|
switch (note->n_type) {
|
|
case ABI_NOTETYPE:
|
|
/* FreeBSD osrel note */
|
|
p = (uintptr_t)(note + 1);
|
|
p += roundup2(note->n_namesz, sizeof(Elf32_Addr));
|
|
obj->osrel = *(const int32_t *)(p);
|
|
dbg("note osrel %d", obj->osrel);
|
|
break;
|
|
case CRT_NOINIT_NOTETYPE:
|
|
/* FreeBSD 'crt does not call init' note */
|
|
obj->crt_no_init = true;
|
|
dbg("note crt_no_init");
|
|
break;
|
|
}
|
|
}
|
|
}
|
|
|
|
static Obj_Entry *
|
|
dlcheck(void *handle)
|
|
{
|
|
Obj_Entry *obj;
|
|
|
|
for (obj = obj_list; obj != NULL; obj = obj->next)
|
|
if (obj == (Obj_Entry *) handle)
|
|
break;
|
|
|
|
if (obj == NULL || obj->refcount == 0 || obj->dl_refcount == 0) {
|
|
_rtld_error("Invalid shared object handle %p", handle);
|
|
return NULL;
|
|
}
|
|
return obj;
|
|
}
|
|
|
|
/*
|
|
* If the given object is already in the donelist, return true. Otherwise
|
|
* add the object to the list and return false.
|
|
*/
|
|
static bool
|
|
donelist_check(DoneList *dlp, const Obj_Entry *obj)
|
|
{
|
|
unsigned int i;
|
|
|
|
for (i = 0; i < dlp->num_used; i++)
|
|
if (dlp->objs[i] == obj)
|
|
return true;
|
|
/*
|
|
* Our donelist allocation should always be sufficient. But if
|
|
* our threads locking isn't working properly, more shared objects
|
|
* could have been loaded since we allocated the list. That should
|
|
* never happen, but we'll handle it properly just in case it does.
|
|
*/
|
|
if (dlp->num_used < dlp->num_alloc)
|
|
dlp->objs[dlp->num_used++] = obj;
|
|
return false;
|
|
}
|
|
|
|
/*
|
|
* Hash function for symbol table lookup. Don't even think about changing
|
|
* this. It is specified by the System V ABI.
|
|
*/
|
|
unsigned long
|
|
elf_hash(const char *name)
|
|
{
|
|
const unsigned char *p = (const unsigned char *) name;
|
|
unsigned long h = 0;
|
|
unsigned long g;
|
|
|
|
while (*p != '\0') {
|
|
h = (h << 4) + *p++;
|
|
if ((g = h & 0xf0000000) != 0)
|
|
h ^= g >> 24;
|
|
h &= ~g;
|
|
}
|
|
return h;
|
|
}
|
|
|
|
/*
|
|
* The GNU hash function is the Daniel J. Bernstein hash clipped to 32 bits
|
|
* unsigned in case it's implemented with a wider type.
|
|
*/
|
|
static uint32_t
|
|
gnu_hash(const char *s)
|
|
{
|
|
uint32_t h;
|
|
unsigned char c;
|
|
|
|
h = 5381;
|
|
for (c = *s; c != '\0'; c = *++s)
|
|
h = h * 33 + c;
|
|
return (h & 0xffffffff);
|
|
}
|
|
|
|
/*
|
|
* Find the library with the given name, and return its full pathname.
|
|
* The returned string is dynamically allocated. Generates an error
|
|
* message and returns NULL if the library cannot be found.
|
|
*
|
|
* If the second argument is non-NULL, then it refers to an already-
|
|
* loaded shared object, whose library search path will be searched.
|
|
*
|
|
* The search order is:
|
|
* DT_RPATH in the referencing file _unless_ DT_RUNPATH is present (1)
|
|
* DT_RPATH of the main object if DSO without defined DT_RUNPATH (1)
|
|
* LD_LIBRARY_PATH
|
|
* DT_RUNPATH in the referencing file
|
|
* ldconfig hints (if -z nodefaultlib, filter out default library directories
|
|
* from list)
|
|
* /lib:/usr/lib _unless_ the referencing file is linked with -z nodefaultlib
|
|
*
|
|
* (1) Handled in digest_dynamic2 - rpath left NULL if runpath defined.
|
|
*/
|
|
static char *
|
|
find_library(const char *xname, const Obj_Entry *refobj)
|
|
{
|
|
char *pathname;
|
|
char *name;
|
|
bool nodeflib, objgiven;
|
|
|
|
objgiven = refobj != NULL;
|
|
if (strchr(xname, '/') != NULL) { /* Hard coded pathname */
|
|
if (xname[0] != '/' && !trust) {
|
|
_rtld_error("Absolute pathname required for shared object \"%s\"",
|
|
xname);
|
|
return NULL;
|
|
}
|
|
if (objgiven && refobj->z_origin) {
|
|
return (origin_subst(__DECONST(char *, xname),
|
|
refobj->origin_path));
|
|
} else {
|
|
return (xstrdup(xname));
|
|
}
|
|
}
|
|
|
|
if (libmap_disable || !objgiven ||
|
|
(name = lm_find(refobj->path, xname)) == NULL)
|
|
name = (char *)xname;
|
|
|
|
dbg(" Searching for \"%s\"", name);
|
|
|
|
/*
|
|
* If refobj->rpath != NULL, then refobj->runpath is NULL. Fall
|
|
* back to pre-conforming behaviour if user requested so with
|
|
* LD_LIBRARY_PATH_RPATH environment variable and ignore -z
|
|
* nodeflib.
|
|
*/
|
|
if (objgiven && refobj->rpath != NULL && ld_library_path_rpath) {
|
|
if ((pathname = search_library_path(name, ld_library_path)) != NULL ||
|
|
(refobj != NULL &&
|
|
(pathname = search_library_path(name, refobj->rpath)) != NULL) ||
|
|
(pathname = search_library_path(name, gethints(false))) != NULL ||
|
|
(pathname = search_library_path(name, STANDARD_LIBRARY_PATH)) != NULL)
|
|
return (pathname);
|
|
} else {
|
|
nodeflib = objgiven ? refobj->z_nodeflib : false;
|
|
if ((objgiven &&
|
|
(pathname = search_library_path(name, refobj->rpath)) != NULL) ||
|
|
(objgiven && refobj->runpath == NULL && refobj != obj_main &&
|
|
(pathname = search_library_path(name, obj_main->rpath)) != NULL) ||
|
|
(pathname = search_library_path(name, ld_library_path)) != NULL ||
|
|
(objgiven &&
|
|
(pathname = search_library_path(name, refobj->runpath)) != NULL) ||
|
|
(pathname = search_library_path(name, gethints(nodeflib))) != NULL ||
|
|
(objgiven && !nodeflib &&
|
|
(pathname = search_library_path(name, STANDARD_LIBRARY_PATH)) != NULL))
|
|
return (pathname);
|
|
}
|
|
|
|
if (objgiven && refobj->path != NULL) {
|
|
_rtld_error("Shared object \"%s\" not found, required by \"%s\"",
|
|
name, basename(refobj->path));
|
|
} else {
|
|
_rtld_error("Shared object \"%s\" not found", name);
|
|
}
|
|
return NULL;
|
|
}
|
|
|
|
/*
|
|
* Given a symbol number in a referencing object, find the corresponding
|
|
* definition of the symbol. Returns a pointer to the symbol, or NULL if
|
|
* no definition was found. Returns a pointer to the Obj_Entry of the
|
|
* defining object via the reference parameter DEFOBJ_OUT.
|
|
*/
|
|
const Elf_Sym *
|
|
find_symdef(unsigned long symnum, const Obj_Entry *refobj,
|
|
const Obj_Entry **defobj_out, int flags, SymCache *cache,
|
|
RtldLockState *lockstate)
|
|
{
|
|
const Elf_Sym *ref;
|
|
const Elf_Sym *def;
|
|
const Obj_Entry *defobj;
|
|
SymLook req;
|
|
const char *name;
|
|
int res;
|
|
|
|
/*
|
|
* If we have already found this symbol, get the information from
|
|
* the cache.
|
|
*/
|
|
if (symnum >= refobj->dynsymcount)
|
|
return NULL; /* Bad object */
|
|
if (cache != NULL && cache[symnum].sym != NULL) {
|
|
*defobj_out = cache[symnum].obj;
|
|
return cache[symnum].sym;
|
|
}
|
|
|
|
ref = refobj->symtab + symnum;
|
|
name = refobj->strtab + ref->st_name;
|
|
def = NULL;
|
|
defobj = NULL;
|
|
|
|
/*
|
|
* We don't have to do a full scale lookup if the symbol is local.
|
|
* We know it will bind to the instance in this load module; to
|
|
* which we already have a pointer (ie ref). By not doing a lookup,
|
|
* we not only improve performance, but it also avoids unresolvable
|
|
* symbols when local symbols are not in the hash table. This has
|
|
* been seen with the ia64 toolchain.
|
|
*/
|
|
if (ELF_ST_BIND(ref->st_info) != STB_LOCAL) {
|
|
if (ELF_ST_TYPE(ref->st_info) == STT_SECTION) {
|
|
_rtld_error("%s: Bogus symbol table entry %lu", refobj->path,
|
|
symnum);
|
|
}
|
|
symlook_init(&req, name);
|
|
req.flags = flags;
|
|
req.ventry = fetch_ventry(refobj, symnum);
|
|
req.lockstate = lockstate;
|
|
res = symlook_default(&req, refobj);
|
|
if (res == 0) {
|
|
def = req.sym_out;
|
|
defobj = req.defobj_out;
|
|
}
|
|
} else {
|
|
def = ref;
|
|
defobj = refobj;
|
|
}
|
|
|
|
/*
|
|
* If we found no definition and the reference is weak, treat the
|
|
* symbol as having the value zero.
|
|
*/
|
|
if (def == NULL && ELF_ST_BIND(ref->st_info) == STB_WEAK) {
|
|
def = &sym_zero;
|
|
defobj = obj_main;
|
|
}
|
|
|
|
if (def != NULL) {
|
|
*defobj_out = defobj;
|
|
/* Record the information in the cache to avoid subsequent lookups. */
|
|
if (cache != NULL) {
|
|
cache[symnum].sym = def;
|
|
cache[symnum].obj = defobj;
|
|
}
|
|
} else {
|
|
if (refobj != &obj_rtld)
|
|
_rtld_error("%s: Undefined symbol \"%s\"", refobj->path, name);
|
|
}
|
|
return def;
|
|
}
|
|
|
|
/*
|
|
* Return the search path from the ldconfig hints file, reading it if
|
|
* necessary. If nostdlib is true, then the default search paths are
|
|
* not added to result.
|
|
*
|
|
* Returns NULL if there are problems with the hints file,
|
|
* or if the search path there is empty.
|
|
*/
|
|
static const char *
|
|
gethints(bool nostdlib)
|
|
{
|
|
static char *hints, *filtered_path;
|
|
struct elfhints_hdr hdr;
|
|
struct fill_search_info_args sargs, hargs;
|
|
struct dl_serinfo smeta, hmeta, *SLPinfo, *hintinfo;
|
|
struct dl_serpath *SLPpath, *hintpath;
|
|
char *p;
|
|
unsigned int SLPndx, hintndx, fndx, fcount;
|
|
int fd;
|
|
size_t flen;
|
|
bool skip;
|
|
|
|
/* First call, read the hints file */
|
|
if (hints == NULL) {
|
|
/* Keep from trying again in case the hints file is bad. */
|
|
hints = "";
|
|
|
|
if ((fd = open(ld_elf_hints_path, O_RDONLY | O_CLOEXEC)) == -1)
|
|
return (NULL);
|
|
if (read(fd, &hdr, sizeof hdr) != sizeof hdr ||
|
|
hdr.magic != ELFHINTS_MAGIC ||
|
|
hdr.version != 1) {
|
|
close(fd);
|
|
return (NULL);
|
|
}
|
|
p = xmalloc(hdr.dirlistlen + 1);
|
|
if (lseek(fd, hdr.strtab + hdr.dirlist, SEEK_SET) == -1 ||
|
|
read(fd, p, hdr.dirlistlen + 1) !=
|
|
(ssize_t)hdr.dirlistlen + 1) {
|
|
free(p);
|
|
close(fd);
|
|
return (NULL);
|
|
}
|
|
hints = p;
|
|
close(fd);
|
|
}
|
|
|
|
/*
|
|
* If caller agreed to receive list which includes the default
|
|
* paths, we are done. Otherwise, if we still did not
|
|
* calculated filtered result, do it now.
|
|
*/
|
|
if (!nostdlib)
|
|
return (hints[0] != '\0' ? hints : NULL);
|
|
if (filtered_path != NULL)
|
|
goto filt_ret;
|
|
|
|
/*
|
|
* Obtain the list of all configured search paths, and the
|
|
* list of the default paths.
|
|
*
|
|
* First estimate the size of the results.
|
|
*/
|
|
smeta.dls_size = __offsetof(struct dl_serinfo, dls_serpath);
|
|
smeta.dls_cnt = 0;
|
|
hmeta.dls_size = __offsetof(struct dl_serinfo, dls_serpath);
|
|
hmeta.dls_cnt = 0;
|
|
|
|
sargs.request = RTLD_DI_SERINFOSIZE;
|
|
sargs.serinfo = &smeta;
|
|
hargs.request = RTLD_DI_SERINFOSIZE;
|
|
hargs.serinfo = &hmeta;
|
|
|
|
path_enumerate(STANDARD_LIBRARY_PATH, fill_search_info, &sargs);
|
|
path_enumerate(p, fill_search_info, &hargs);
|
|
|
|
SLPinfo = xmalloc(smeta.dls_size);
|
|
hintinfo = xmalloc(hmeta.dls_size);
|
|
|
|
/*
|
|
* Next fetch both sets of paths.
|
|
*/
|
|
sargs.request = RTLD_DI_SERINFO;
|
|
sargs.serinfo = SLPinfo;
|
|
sargs.serpath = &SLPinfo->dls_serpath[0];
|
|
sargs.strspace = (char *)&SLPinfo->dls_serpath[smeta.dls_cnt];
|
|
|
|
hargs.request = RTLD_DI_SERINFO;
|
|
hargs.serinfo = hintinfo;
|
|
hargs.serpath = &hintinfo->dls_serpath[0];
|
|
hargs.strspace = (char *)&hintinfo->dls_serpath[hmeta.dls_cnt];
|
|
|
|
path_enumerate(STANDARD_LIBRARY_PATH, fill_search_info, &sargs);
|
|
path_enumerate(p, fill_search_info, &hargs);
|
|
|
|
/*
|
|
* Now calculate the difference between two sets, by excluding
|
|
* standard paths from the full set.
|
|
*/
|
|
fndx = 0;
|
|
fcount = 0;
|
|
filtered_path = xmalloc(hdr.dirlistlen + 1);
|
|
hintpath = &hintinfo->dls_serpath[0];
|
|
for (hintndx = 0; hintndx < hmeta.dls_cnt; hintndx++, hintpath++) {
|
|
skip = false;
|
|
SLPpath = &SLPinfo->dls_serpath[0];
|
|
/*
|
|
* Check each standard path against current.
|
|
*/
|
|
for (SLPndx = 0; SLPndx < smeta.dls_cnt; SLPndx++, SLPpath++) {
|
|
/* matched, skip the path */
|
|
if (!strcmp(hintpath->dls_name, SLPpath->dls_name)) {
|
|
skip = true;
|
|
break;
|
|
}
|
|
}
|
|
if (skip)
|
|
continue;
|
|
/*
|
|
* Not matched against any standard path, add the path
|
|
* to result. Separate consequtive paths with ':'.
|
|
*/
|
|
if (fcount > 0) {
|
|
filtered_path[fndx] = ':';
|
|
fndx++;
|
|
}
|
|
fcount++;
|
|
flen = strlen(hintpath->dls_name);
|
|
strncpy((filtered_path + fndx), hintpath->dls_name, flen);
|
|
fndx += flen;
|
|
}
|
|
filtered_path[fndx] = '\0';
|
|
|
|
free(SLPinfo);
|
|
free(hintinfo);
|
|
|
|
filt_ret:
|
|
return (filtered_path[0] != '\0' ? filtered_path : NULL);
|
|
}
|
|
|
|
static void
|
|
init_dag(Obj_Entry *root)
|
|
{
|
|
const Needed_Entry *needed;
|
|
const Objlist_Entry *elm;
|
|
DoneList donelist;
|
|
|
|
if (root->dag_inited)
|
|
return;
|
|
donelist_init(&donelist);
|
|
|
|
/* Root object belongs to own DAG. */
|
|
objlist_push_tail(&root->dldags, root);
|
|
objlist_push_tail(&root->dagmembers, root);
|
|
donelist_check(&donelist, root);
|
|
|
|
/*
|
|
* Add dependencies of root object to DAG in breadth order
|
|
* by exploiting the fact that each new object get added
|
|
* to the tail of the dagmembers list.
|
|
*/
|
|
STAILQ_FOREACH(elm, &root->dagmembers, link) {
|
|
for (needed = elm->obj->needed; needed != NULL; needed = needed->next) {
|
|
if (needed->obj == NULL || donelist_check(&donelist, needed->obj))
|
|
continue;
|
|
objlist_push_tail(&needed->obj->dldags, root);
|
|
objlist_push_tail(&root->dagmembers, needed->obj);
|
|
}
|
|
}
|
|
root->dag_inited = true;
|
|
}
|
|
|
|
static void
|
|
process_nodelete(Obj_Entry *root)
|
|
{
|
|
const Objlist_Entry *elm;
|
|
|
|
/*
|
|
* Walk over object DAG and process every dependent object that
|
|
* is marked as DF_1_NODELETE. They need to grow their own DAG,
|
|
* which then should have its reference upped separately.
|
|
*/
|
|
STAILQ_FOREACH(elm, &root->dagmembers, link) {
|
|
if (elm->obj != NULL && elm->obj->z_nodelete &&
|
|
!elm->obj->ref_nodel) {
|
|
dbg("obj %s nodelete", elm->obj->path);
|
|
init_dag(elm->obj);
|
|
ref_dag(elm->obj);
|
|
elm->obj->ref_nodel = true;
|
|
}
|
|
}
|
|
}
|
|
/*
|
|
* Initialize the dynamic linker. The argument is the address at which
|
|
* the dynamic linker has been mapped into memory. The primary task of
|
|
* this function is to relocate the dynamic linker.
|
|
*/
|
|
static void
|
|
init_rtld(caddr_t mapbase, Elf_Auxinfo **aux_info)
|
|
{
|
|
Obj_Entry objtmp; /* Temporary rtld object */
|
|
const Elf_Dyn *dyn_rpath;
|
|
const Elf_Dyn *dyn_soname;
|
|
const Elf_Dyn *dyn_runpath;
|
|
|
|
/*
|
|
* Conjure up an Obj_Entry structure for the dynamic linker.
|
|
*
|
|
* The "path" member can't be initialized yet because string constants
|
|
* cannot yet be accessed. Below we will set it correctly.
|
|
*/
|
|
memset(&objtmp, 0, sizeof(objtmp));
|
|
objtmp.path = NULL;
|
|
objtmp.rtld = true;
|
|
objtmp.mapbase = mapbase;
|
|
#ifdef PIC
|
|
objtmp.relocbase = mapbase;
|
|
#endif
|
|
if (RTLD_IS_DYNAMIC()) {
|
|
objtmp.dynamic = rtld_dynamic(&objtmp);
|
|
digest_dynamic1(&objtmp, 1, &dyn_rpath, &dyn_soname, &dyn_runpath);
|
|
assert(objtmp.needed == NULL);
|
|
#if !defined(__mips__)
|
|
/* MIPS has a bogus DT_TEXTREL. */
|
|
assert(!objtmp.textrel);
|
|
#endif
|
|
|
|
/*
|
|
* Temporarily put the dynamic linker entry into the object list, so
|
|
* that symbols can be found.
|
|
*/
|
|
|
|
relocate_objects(&objtmp, true, &objtmp, 0, NULL);
|
|
}
|
|
|
|
/* Initialize the object list. */
|
|
obj_tail = &obj_list;
|
|
|
|
/* Now that non-local variables can be accesses, copy out obj_rtld. */
|
|
memcpy(&obj_rtld, &objtmp, sizeof(obj_rtld));
|
|
|
|
if (aux_info[AT_PAGESZ] != NULL)
|
|
pagesize = aux_info[AT_PAGESZ]->a_un.a_val;
|
|
if (aux_info[AT_OSRELDATE] != NULL)
|
|
osreldate = aux_info[AT_OSRELDATE]->a_un.a_val;
|
|
|
|
digest_dynamic2(&obj_rtld, dyn_rpath, dyn_soname, dyn_runpath);
|
|
|
|
/* Replace the path with a dynamically allocated copy. */
|
|
obj_rtld.path = xstrdup(PATH_RTLD);
|
|
|
|
r_debug.r_brk = r_debug_state;
|
|
r_debug.r_state = RT_CONSISTENT;
|
|
}
|
|
|
|
/*
|
|
* Add the init functions from a needed object list (and its recursive
|
|
* needed objects) to "list". This is not used directly; it is a helper
|
|
* function for initlist_add_objects(). The write lock must be held
|
|
* when this function is called.
|
|
*/
|
|
static void
|
|
initlist_add_neededs(Needed_Entry *needed, Objlist *list)
|
|
{
|
|
/* Recursively process the successor needed objects. */
|
|
if (needed->next != NULL)
|
|
initlist_add_neededs(needed->next, list);
|
|
|
|
/* Process the current needed object. */
|
|
if (needed->obj != NULL)
|
|
initlist_add_objects(needed->obj, &needed->obj->next, list);
|
|
}
|
|
|
|
/*
|
|
* Scan all of the DAGs rooted in the range of objects from "obj" to
|
|
* "tail" and add their init functions to "list". This recurses over
|
|
* the DAGs and ensure the proper init ordering such that each object's
|
|
* needed libraries are initialized before the object itself. At the
|
|
* same time, this function adds the objects to the global finalization
|
|
* list "list_fini" in the opposite order. The write lock must be
|
|
* held when this function is called.
|
|
*/
|
|
static void
|
|
initlist_add_objects(Obj_Entry *obj, Obj_Entry **tail, Objlist *list)
|
|
{
|
|
|
|
if (obj->init_scanned || obj->init_done)
|
|
return;
|
|
obj->init_scanned = true;
|
|
|
|
/* Recursively process the successor objects. */
|
|
if (&obj->next != tail)
|
|
initlist_add_objects(obj->next, tail, list);
|
|
|
|
/* Recursively process the needed objects. */
|
|
if (obj->needed != NULL)
|
|
initlist_add_neededs(obj->needed, list);
|
|
if (obj->needed_filtees != NULL)
|
|
initlist_add_neededs(obj->needed_filtees, list);
|
|
if (obj->needed_aux_filtees != NULL)
|
|
initlist_add_neededs(obj->needed_aux_filtees, list);
|
|
|
|
/* Add the object to the init list. */
|
|
if (obj->preinit_array != (Elf_Addr)NULL || obj->init != (Elf_Addr)NULL ||
|
|
obj->init_array != (Elf_Addr)NULL)
|
|
objlist_push_tail(list, obj);
|
|
|
|
/* Add the object to the global fini list in the reverse order. */
|
|
if ((obj->fini != (Elf_Addr)NULL || obj->fini_array != (Elf_Addr)NULL)
|
|
&& !obj->on_fini_list) {
|
|
objlist_push_head(&list_fini, obj);
|
|
obj->on_fini_list = true;
|
|
}
|
|
}
|
|
|
|
#ifndef FPTR_TARGET
|
|
#define FPTR_TARGET(f) ((Elf_Addr) (f))
|
|
#endif
|
|
|
|
static void
|
|
free_needed_filtees(Needed_Entry *n)
|
|
{
|
|
Needed_Entry *needed, *needed1;
|
|
|
|
for (needed = n; needed != NULL; needed = needed->next) {
|
|
if (needed->obj != NULL) {
|
|
dlclose(needed->obj);
|
|
needed->obj = NULL;
|
|
}
|
|
}
|
|
for (needed = n; needed != NULL; needed = needed1) {
|
|
needed1 = needed->next;
|
|
free(needed);
|
|
}
|
|
}
|
|
|
|
static void
|
|
unload_filtees(Obj_Entry *obj)
|
|
{
|
|
|
|
free_needed_filtees(obj->needed_filtees);
|
|
obj->needed_filtees = NULL;
|
|
free_needed_filtees(obj->needed_aux_filtees);
|
|
obj->needed_aux_filtees = NULL;
|
|
obj->filtees_loaded = false;
|
|
}
|
|
|
|
static void
|
|
load_filtee1(Obj_Entry *obj, Needed_Entry *needed, int flags,
|
|
RtldLockState *lockstate)
|
|
{
|
|
|
|
for (; needed != NULL; needed = needed->next) {
|
|
needed->obj = dlopen_object(obj->strtab + needed->name, -1, obj,
|
|
flags, ((ld_loadfltr || obj->z_loadfltr) ? RTLD_NOW : RTLD_LAZY) |
|
|
RTLD_LOCAL, lockstate);
|
|
}
|
|
}
|
|
|
|
static void
|
|
load_filtees(Obj_Entry *obj, int flags, RtldLockState *lockstate)
|
|
{
|
|
|
|
lock_restart_for_upgrade(lockstate);
|
|
if (!obj->filtees_loaded) {
|
|
load_filtee1(obj, obj->needed_filtees, flags, lockstate);
|
|
load_filtee1(obj, obj->needed_aux_filtees, flags, lockstate);
|
|
obj->filtees_loaded = true;
|
|
}
|
|
}
|
|
|
|
static int
|
|
process_needed(Obj_Entry *obj, Needed_Entry *needed, int flags)
|
|
{
|
|
Obj_Entry *obj1;
|
|
|
|
for (; needed != NULL; needed = needed->next) {
|
|
obj1 = needed->obj = load_object(obj->strtab + needed->name, -1, obj,
|
|
flags & ~RTLD_LO_NOLOAD);
|
|
if (obj1 == NULL && !ld_tracing && (flags & RTLD_LO_FILTEES) == 0)
|
|
return (-1);
|
|
}
|
|
return (0);
|
|
}
|
|
|
|
/*
|
|
* Given a shared object, traverse its list of needed objects, and load
|
|
* each of them. Returns 0 on success. Generates an error message and
|
|
* returns -1 on failure.
|
|
*/
|
|
static int
|
|
load_needed_objects(Obj_Entry *first, int flags)
|
|
{
|
|
Obj_Entry *obj;
|
|
|
|
for (obj = first; obj != NULL; obj = obj->next) {
|
|
if (process_needed(obj, obj->needed, flags) == -1)
|
|
return (-1);
|
|
}
|
|
return (0);
|
|
}
|
|
|
|
static int
|
|
load_preload_objects(void)
|
|
{
|
|
char *p = ld_preload;
|
|
Obj_Entry *obj;
|
|
static const char delim[] = " \t:;";
|
|
|
|
if (p == NULL)
|
|
return 0;
|
|
|
|
p += strspn(p, delim);
|
|
while (*p != '\0') {
|
|
size_t len = strcspn(p, delim);
|
|
char savech;
|
|
|
|
savech = p[len];
|
|
p[len] = '\0';
|
|
obj = load_object(p, -1, NULL, 0);
|
|
if (obj == NULL)
|
|
return -1; /* XXX - cleanup */
|
|
obj->z_interpose = true;
|
|
p[len] = savech;
|
|
p += len;
|
|
p += strspn(p, delim);
|
|
}
|
|
LD_UTRACE(UTRACE_PRELOAD_FINISHED, NULL, NULL, 0, 0, NULL);
|
|
return 0;
|
|
}
|
|
|
|
static const char *
|
|
printable_path(const char *path)
|
|
{
|
|
|
|
return (path == NULL ? "<unknown>" : path);
|
|
}
|
|
|
|
/*
|
|
* Load a shared object into memory, if it is not already loaded. The
|
|
* object may be specified by name or by user-supplied file descriptor
|
|
* fd_u. In the later case, the fd_u descriptor is not closed, but its
|
|
* duplicate is.
|
|
*
|
|
* Returns a pointer to the Obj_Entry for the object. Returns NULL
|
|
* on failure.
|
|
*/
|
|
static Obj_Entry *
|
|
load_object(const char *name, int fd_u, const Obj_Entry *refobj, int flags)
|
|
{
|
|
Obj_Entry *obj;
|
|
int fd;
|
|
struct stat sb;
|
|
char *path;
|
|
|
|
if (name != NULL) {
|
|
for (obj = obj_list->next; obj != NULL; obj = obj->next) {
|
|
if (object_match_name(obj, name))
|
|
return (obj);
|
|
}
|
|
|
|
path = find_library(name, refobj);
|
|
if (path == NULL)
|
|
return (NULL);
|
|
} else
|
|
path = NULL;
|
|
|
|
/*
|
|
* If we didn't find a match by pathname, or the name is not
|
|
* supplied, open the file and check again by device and inode.
|
|
* This avoids false mismatches caused by multiple links or ".."
|
|
* in pathnames.
|
|
*
|
|
* To avoid a race, we open the file and use fstat() rather than
|
|
* using stat().
|
|
*/
|
|
fd = -1;
|
|
if (fd_u == -1) {
|
|
if ((fd = open(path, O_RDONLY | O_CLOEXEC)) == -1) {
|
|
_rtld_error("Cannot open \"%s\"", path);
|
|
free(path);
|
|
return (NULL);
|
|
}
|
|
} else {
|
|
fd = fcntl(fd_u, F_DUPFD_CLOEXEC, 0);
|
|
if (fd == -1) {
|
|
_rtld_error("Cannot dup fd");
|
|
free(path);
|
|
return (NULL);
|
|
}
|
|
}
|
|
if (fstat(fd, &sb) == -1) {
|
|
_rtld_error("Cannot fstat \"%s\"", printable_path(path));
|
|
close(fd);
|
|
free(path);
|
|
return NULL;
|
|
}
|
|
for (obj = obj_list->next; obj != NULL; obj = obj->next)
|
|
if (obj->ino == sb.st_ino && obj->dev == sb.st_dev)
|
|
break;
|
|
if (obj != NULL && name != NULL) {
|
|
object_add_name(obj, name);
|
|
free(path);
|
|
close(fd);
|
|
return obj;
|
|
}
|
|
if (flags & RTLD_LO_NOLOAD) {
|
|
free(path);
|
|
close(fd);
|
|
return (NULL);
|
|
}
|
|
|
|
/* First use of this object, so we must map it in */
|
|
obj = do_load_object(fd, name, path, &sb, flags);
|
|
if (obj == NULL)
|
|
free(path);
|
|
close(fd);
|
|
|
|
return obj;
|
|
}
|
|
|
|
static Obj_Entry *
|
|
do_load_object(int fd, const char *name, char *path, struct stat *sbp,
|
|
int flags)
|
|
{
|
|
Obj_Entry *obj;
|
|
struct statfs fs;
|
|
|
|
/*
|
|
* but first, make sure that environment variables haven't been
|
|
* used to circumvent the noexec flag on a filesystem.
|
|
*/
|
|
if (dangerous_ld_env) {
|
|
if (fstatfs(fd, &fs) != 0) {
|
|
_rtld_error("Cannot fstatfs \"%s\"", printable_path(path));
|
|
return NULL;
|
|
}
|
|
if (fs.f_flags & MNT_NOEXEC) {
|
|
_rtld_error("Cannot execute objects on %s\n", fs.f_mntonname);
|
|
return NULL;
|
|
}
|
|
}
|
|
dbg("loading \"%s\"", printable_path(path));
|
|
obj = map_object(fd, printable_path(path), sbp);
|
|
if (obj == NULL)
|
|
return NULL;
|
|
|
|
/*
|
|
* If DT_SONAME is present in the object, digest_dynamic2 already
|
|
* added it to the object names.
|
|
*/
|
|
if (name != NULL)
|
|
object_add_name(obj, name);
|
|
obj->path = path;
|
|
digest_dynamic(obj, 0);
|
|
dbg("%s valid_hash_sysv %d valid_hash_gnu %d dynsymcount %d", obj->path,
|
|
obj->valid_hash_sysv, obj->valid_hash_gnu, obj->dynsymcount);
|
|
if (obj->z_noopen && (flags & (RTLD_LO_DLOPEN | RTLD_LO_TRACE)) ==
|
|
RTLD_LO_DLOPEN) {
|
|
dbg("refusing to load non-loadable \"%s\"", obj->path);
|
|
_rtld_error("Cannot dlopen non-loadable %s", obj->path);
|
|
munmap(obj->mapbase, obj->mapsize);
|
|
obj_free(obj);
|
|
return (NULL);
|
|
}
|
|
|
|
obj->dlopened = (flags & RTLD_LO_DLOPEN) != 0;
|
|
*obj_tail = obj;
|
|
obj_tail = &obj->next;
|
|
obj_count++;
|
|
obj_loads++;
|
|
linkmap_add(obj); /* for GDB & dlinfo() */
|
|
max_stack_flags |= obj->stack_flags;
|
|
|
|
dbg(" %p .. %p: %s", obj->mapbase,
|
|
obj->mapbase + obj->mapsize - 1, obj->path);
|
|
if (obj->textrel)
|
|
dbg(" WARNING: %s has impure text", obj->path);
|
|
LD_UTRACE(UTRACE_LOAD_OBJECT, obj, obj->mapbase, obj->mapsize, 0,
|
|
obj->path);
|
|
|
|
return obj;
|
|
}
|
|
|
|
static Obj_Entry *
|
|
obj_from_addr(const void *addr)
|
|
{
|
|
Obj_Entry *obj;
|
|
|
|
for (obj = obj_list; obj != NULL; obj = obj->next) {
|
|
if (addr < (void *) obj->mapbase)
|
|
continue;
|
|
if (addr < (void *) (obj->mapbase + obj->mapsize))
|
|
return obj;
|
|
}
|
|
return NULL;
|
|
}
|
|
|
|
static void
|
|
preinit_main(void)
|
|
{
|
|
Elf_Addr *preinit_addr;
|
|
int index;
|
|
|
|
preinit_addr = (Elf_Addr *)obj_main->preinit_array;
|
|
if (preinit_addr == NULL)
|
|
return;
|
|
|
|
for (index = 0; index < obj_main->preinit_array_num; index++) {
|
|
if (preinit_addr[index] != 0 && preinit_addr[index] != 1) {
|
|
dbg("calling preinit function for %s at %p", obj_main->path,
|
|
(void *)preinit_addr[index]);
|
|
LD_UTRACE(UTRACE_INIT_CALL, obj_main, (void *)preinit_addr[index],
|
|
0, 0, obj_main->path);
|
|
call_init_pointer(obj_main, preinit_addr[index]);
|
|
}
|
|
}
|
|
}
|
|
|
|
/*
|
|
* Call the finalization functions for each of the objects in "list"
|
|
* belonging to the DAG of "root" and referenced once. If NULL "root"
|
|
* is specified, every finalization function will be called regardless
|
|
* of the reference count and the list elements won't be freed. All of
|
|
* the objects are expected to have non-NULL fini functions.
|
|
*/
|
|
static void
|
|
objlist_call_fini(Objlist *list, Obj_Entry *root, RtldLockState *lockstate)
|
|
{
|
|
Objlist_Entry *elm;
|
|
char *saved_msg;
|
|
Elf_Addr *fini_addr;
|
|
int index;
|
|
|
|
assert(root == NULL || root->refcount == 1);
|
|
|
|
/*
|
|
* Preserve the current error message since a fini function might
|
|
* call into the dynamic linker and overwrite it.
|
|
*/
|
|
saved_msg = errmsg_save();
|
|
do {
|
|
STAILQ_FOREACH(elm, list, link) {
|
|
if (root != NULL && (elm->obj->refcount != 1 ||
|
|
objlist_find(&root->dagmembers, elm->obj) == NULL))
|
|
continue;
|
|
/* Remove object from fini list to prevent recursive invocation. */
|
|
STAILQ_REMOVE(list, elm, Struct_Objlist_Entry, link);
|
|
/*
|
|
* XXX: If a dlopen() call references an object while the
|
|
* fini function is in progress, we might end up trying to
|
|
* unload the referenced object in dlclose() or the object
|
|
* won't be unloaded although its fini function has been
|
|
* called.
|
|
*/
|
|
lock_release(rtld_bind_lock, lockstate);
|
|
|
|
/*
|
|
* It is legal to have both DT_FINI and DT_FINI_ARRAY defined.
|
|
* When this happens, DT_FINI_ARRAY is processed first.
|
|
*/
|
|
fini_addr = (Elf_Addr *)elm->obj->fini_array;
|
|
if (fini_addr != NULL && elm->obj->fini_array_num > 0) {
|
|
for (index = elm->obj->fini_array_num - 1; index >= 0;
|
|
index--) {
|
|
if (fini_addr[index] != 0 && fini_addr[index] != 1) {
|
|
dbg("calling fini function for %s at %p",
|
|
elm->obj->path, (void *)fini_addr[index]);
|
|
LD_UTRACE(UTRACE_FINI_CALL, elm->obj,
|
|
(void *)fini_addr[index], 0, 0, elm->obj->path);
|
|
call_initfini_pointer(elm->obj, fini_addr[index]);
|
|
}
|
|
}
|
|
}
|
|
if (elm->obj->fini != (Elf_Addr)NULL) {
|
|
dbg("calling fini function for %s at %p", elm->obj->path,
|
|
(void *)elm->obj->fini);
|
|
LD_UTRACE(UTRACE_FINI_CALL, elm->obj, (void *)elm->obj->fini,
|
|
0, 0, elm->obj->path);
|
|
call_initfini_pointer(elm->obj, elm->obj->fini);
|
|
}
|
|
wlock_acquire(rtld_bind_lock, lockstate);
|
|
/* No need to free anything if process is going down. */
|
|
if (root != NULL)
|
|
free(elm);
|
|
/*
|
|
* We must restart the list traversal after every fini call
|
|
* because a dlclose() call from the fini function or from
|
|
* another thread might have modified the reference counts.
|
|
*/
|
|
break;
|
|
}
|
|
} while (elm != NULL);
|
|
errmsg_restore(saved_msg);
|
|
}
|
|
|
|
/*
|
|
* Call the initialization functions for each of the objects in
|
|
* "list". All of the objects are expected to have non-NULL init
|
|
* functions.
|
|
*/
|
|
static void
|
|
objlist_call_init(Objlist *list, RtldLockState *lockstate)
|
|
{
|
|
Objlist_Entry *elm;
|
|
Obj_Entry *obj;
|
|
char *saved_msg;
|
|
Elf_Addr *init_addr;
|
|
int index;
|
|
|
|
/*
|
|
* Clean init_scanned flag so that objects can be rechecked and
|
|
* possibly initialized earlier if any of vectors called below
|
|
* cause the change by using dlopen.
|
|
*/
|
|
for (obj = obj_list; obj != NULL; obj = obj->next)
|
|
obj->init_scanned = false;
|
|
|
|
/*
|
|
* Preserve the current error message since an init function might
|
|
* call into the dynamic linker and overwrite it.
|
|
*/
|
|
saved_msg = errmsg_save();
|
|
STAILQ_FOREACH(elm, list, link) {
|
|
if (elm->obj->init_done) /* Initialized early. */
|
|
continue;
|
|
/*
|
|
* Race: other thread might try to use this object before current
|
|
* one completes the initilization. Not much can be done here
|
|
* without better locking.
|
|
*/
|
|
elm->obj->init_done = true;
|
|
lock_release(rtld_bind_lock, lockstate);
|
|
|
|
/*
|
|
* It is legal to have both DT_INIT and DT_INIT_ARRAY defined.
|
|
* When this happens, DT_INIT is processed first.
|
|
*/
|
|
if (elm->obj->init != (Elf_Addr)NULL) {
|
|
dbg("calling init function for %s at %p", elm->obj->path,
|
|
(void *)elm->obj->init);
|
|
LD_UTRACE(UTRACE_INIT_CALL, elm->obj, (void *)elm->obj->init,
|
|
0, 0, elm->obj->path);
|
|
call_initfini_pointer(elm->obj, elm->obj->init);
|
|
}
|
|
init_addr = (Elf_Addr *)elm->obj->init_array;
|
|
if (init_addr != NULL) {
|
|
for (index = 0; index < elm->obj->init_array_num; index++) {
|
|
if (init_addr[index] != 0 && init_addr[index] != 1) {
|
|
dbg("calling init function for %s at %p", elm->obj->path,
|
|
(void *)init_addr[index]);
|
|
LD_UTRACE(UTRACE_INIT_CALL, elm->obj,
|
|
(void *)init_addr[index], 0, 0, elm->obj->path);
|
|
call_init_pointer(elm->obj, init_addr[index]);
|
|
}
|
|
}
|
|
}
|
|
wlock_acquire(rtld_bind_lock, lockstate);
|
|
}
|
|
errmsg_restore(saved_msg);
|
|
}
|
|
|
|
static void
|
|
objlist_clear(Objlist *list)
|
|
{
|
|
Objlist_Entry *elm;
|
|
|
|
while (!STAILQ_EMPTY(list)) {
|
|
elm = STAILQ_FIRST(list);
|
|
STAILQ_REMOVE_HEAD(list, link);
|
|
free(elm);
|
|
}
|
|
}
|
|
|
|
static Objlist_Entry *
|
|
objlist_find(Objlist *list, const Obj_Entry *obj)
|
|
{
|
|
Objlist_Entry *elm;
|
|
|
|
STAILQ_FOREACH(elm, list, link)
|
|
if (elm->obj == obj)
|
|
return elm;
|
|
return NULL;
|
|
}
|
|
|
|
static void
|
|
objlist_init(Objlist *list)
|
|
{
|
|
STAILQ_INIT(list);
|
|
}
|
|
|
|
static void
|
|
objlist_push_head(Objlist *list, Obj_Entry *obj)
|
|
{
|
|
Objlist_Entry *elm;
|
|
|
|
elm = NEW(Objlist_Entry);
|
|
elm->obj = obj;
|
|
STAILQ_INSERT_HEAD(list, elm, link);
|
|
}
|
|
|
|
static void
|
|
objlist_push_tail(Objlist *list, Obj_Entry *obj)
|
|
{
|
|
Objlist_Entry *elm;
|
|
|
|
elm = NEW(Objlist_Entry);
|
|
elm->obj = obj;
|
|
STAILQ_INSERT_TAIL(list, elm, link);
|
|
}
|
|
|
|
static void
|
|
objlist_put_after(Objlist *list, Obj_Entry *listobj, Obj_Entry *obj)
|
|
{
|
|
Objlist_Entry *elm, *listelm;
|
|
|
|
STAILQ_FOREACH(listelm, list, link) {
|
|
if (listelm->obj == listobj)
|
|
break;
|
|
}
|
|
elm = NEW(Objlist_Entry);
|
|
elm->obj = obj;
|
|
if (listelm != NULL)
|
|
STAILQ_INSERT_AFTER(list, listelm, elm, link);
|
|
else
|
|
STAILQ_INSERT_TAIL(list, elm, link);
|
|
}
|
|
|
|
static void
|
|
objlist_remove(Objlist *list, Obj_Entry *obj)
|
|
{
|
|
Objlist_Entry *elm;
|
|
|
|
if ((elm = objlist_find(list, obj)) != NULL) {
|
|
STAILQ_REMOVE(list, elm, Struct_Objlist_Entry, link);
|
|
free(elm);
|
|
}
|
|
}
|
|
|
|
/*
|
|
* Relocate dag rooted in the specified object.
|
|
* Returns 0 on success, or -1 on failure.
|
|
*/
|
|
|
|
static int
|
|
relocate_object_dag(Obj_Entry *root, bool bind_now, Obj_Entry *rtldobj,
|
|
int flags, RtldLockState *lockstate)
|
|
{
|
|
Objlist_Entry *elm;
|
|
int error;
|
|
|
|
error = 0;
|
|
STAILQ_FOREACH(elm, &root->dagmembers, link) {
|
|
error = relocate_object(elm->obj, bind_now, rtldobj, flags,
|
|
lockstate);
|
|
if (error == -1)
|
|
break;
|
|
}
|
|
return (error);
|
|
}
|
|
|
|
/*
|
|
* Relocate single object.
|
|
* Returns 0 on success, or -1 on failure.
|
|
*/
|
|
static int
|
|
relocate_object(Obj_Entry *obj, bool bind_now, Obj_Entry *rtldobj,
|
|
int flags, RtldLockState *lockstate)
|
|
{
|
|
|
|
if (obj->relocated)
|
|
return (0);
|
|
obj->relocated = true;
|
|
if (obj != rtldobj)
|
|
dbg("relocating \"%s\"", obj->path);
|
|
|
|
if (obj->symtab == NULL || obj->strtab == NULL ||
|
|
!(obj->valid_hash_sysv || obj->valid_hash_gnu)) {
|
|
_rtld_error("%s: Shared object has no run-time symbol table",
|
|
obj->path);
|
|
return (-1);
|
|
}
|
|
|
|
if (obj->textrel) {
|
|
/* There are relocations to the write-protected text segment. */
|
|
if (mprotect(obj->mapbase, obj->textsize,
|
|
PROT_READ|PROT_WRITE|PROT_EXEC) == -1) {
|
|
_rtld_error("%s: Cannot write-enable text segment: %s",
|
|
obj->path, rtld_strerror(errno));
|
|
return (-1);
|
|
}
|
|
}
|
|
|
|
/* Process the non-PLT non-IFUNC relocations. */
|
|
if (reloc_non_plt(obj, rtldobj, flags, lockstate))
|
|
return (-1);
|
|
|
|
if (obj->textrel) { /* Re-protected the text segment. */
|
|
if (mprotect(obj->mapbase, obj->textsize,
|
|
PROT_READ|PROT_EXEC) == -1) {
|
|
_rtld_error("%s: Cannot write-protect text segment: %s",
|
|
obj->path, rtld_strerror(errno));
|
|
return (-1);
|
|
}
|
|
}
|
|
|
|
/* Set the special PLT or GOT entries. */
|
|
init_pltgot(obj);
|
|
|
|
/* Process the PLT relocations. */
|
|
if (reloc_plt(obj) == -1)
|
|
return (-1);
|
|
/* Relocate the jump slots if we are doing immediate binding. */
|
|
if (obj->bind_now || bind_now)
|
|
if (reloc_jmpslots(obj, flags, lockstate) == -1)
|
|
return (-1);
|
|
|
|
/*
|
|
* Process the non-PLT IFUNC relocations. The relocations are
|
|
* processed in two phases, because IFUNC resolvers may
|
|
* reference other symbols, which must be readily processed
|
|
* before resolvers are called.
|
|
*/
|
|
if (obj->non_plt_gnu_ifunc &&
|
|
reloc_non_plt(obj, rtldobj, flags | SYMLOOK_IFUNC, lockstate))
|
|
return (-1);
|
|
|
|
if (obj->relro_size > 0) {
|
|
if (mprotect(obj->relro_page, obj->relro_size,
|
|
PROT_READ) == -1) {
|
|
_rtld_error("%s: Cannot enforce relro protection: %s",
|
|
obj->path, rtld_strerror(errno));
|
|
return (-1);
|
|
}
|
|
}
|
|
|
|
/*
|
|
* Set up the magic number and version in the Obj_Entry. These
|
|
* were checked in the crt1.o from the original ElfKit, so we
|
|
* set them for backward compatibility.
|
|
*/
|
|
obj->magic = RTLD_MAGIC;
|
|
obj->version = RTLD_VERSION;
|
|
|
|
return (0);
|
|
}
|
|
|
|
/*
|
|
* Relocate newly-loaded shared objects. The argument is a pointer to
|
|
* the Obj_Entry for the first such object. All objects from the first
|
|
* to the end of the list of objects are relocated. Returns 0 on success,
|
|
* or -1 on failure.
|
|
*/
|
|
static int
|
|
relocate_objects(Obj_Entry *first, bool bind_now, Obj_Entry *rtldobj,
|
|
int flags, RtldLockState *lockstate)
|
|
{
|
|
Obj_Entry *obj;
|
|
int error;
|
|
|
|
for (error = 0, obj = first; obj != NULL; obj = obj->next) {
|
|
error = relocate_object(obj, bind_now, rtldobj, flags,
|
|
lockstate);
|
|
if (error == -1)
|
|
break;
|
|
}
|
|
return (error);
|
|
}
|
|
|
|
/*
|
|
* The handling of R_MACHINE_IRELATIVE relocations and jumpslots
|
|
* referencing STT_GNU_IFUNC symbols is postponed till the other
|
|
* relocations are done. The indirect functions specified as
|
|
* ifunc are allowed to call other symbols, so we need to have
|
|
* objects relocated before asking for resolution from indirects.
|
|
*
|
|
* The R_MACHINE_IRELATIVE slots are resolved in greedy fashion,
|
|
* instead of the usual lazy handling of PLT slots. It is
|
|
* consistent with how GNU does it.
|
|
*/
|
|
static int
|
|
resolve_object_ifunc(Obj_Entry *obj, bool bind_now, int flags,
|
|
RtldLockState *lockstate)
|
|
{
|
|
if (obj->irelative && reloc_iresolve(obj, lockstate) == -1)
|
|
return (-1);
|
|
if ((obj->bind_now || bind_now) && obj->gnu_ifunc &&
|
|
reloc_gnu_ifunc(obj, flags, lockstate) == -1)
|
|
return (-1);
|
|
return (0);
|
|
}
|
|
|
|
static int
|
|
resolve_objects_ifunc(Obj_Entry *first, bool bind_now, int flags,
|
|
RtldLockState *lockstate)
|
|
{
|
|
Obj_Entry *obj;
|
|
|
|
for (obj = first; obj != NULL; obj = obj->next) {
|
|
if (resolve_object_ifunc(obj, bind_now, flags, lockstate) == -1)
|
|
return (-1);
|
|
}
|
|
return (0);
|
|
}
|
|
|
|
static int
|
|
initlist_objects_ifunc(Objlist *list, bool bind_now, int flags,
|
|
RtldLockState *lockstate)
|
|
{
|
|
Objlist_Entry *elm;
|
|
|
|
STAILQ_FOREACH(elm, list, link) {
|
|
if (resolve_object_ifunc(elm->obj, bind_now, flags,
|
|
lockstate) == -1)
|
|
return (-1);
|
|
}
|
|
return (0);
|
|
}
|
|
|
|
/*
|
|
* Cleanup procedure. It will be called (by the atexit mechanism) just
|
|
* before the process exits.
|
|
*/
|
|
static void
|
|
rtld_exit(void)
|
|
{
|
|
RtldLockState lockstate;
|
|
|
|
wlock_acquire(rtld_bind_lock, &lockstate);
|
|
dbg("rtld_exit()");
|
|
objlist_call_fini(&list_fini, NULL, &lockstate);
|
|
/* No need to remove the items from the list, since we are exiting. */
|
|
if (!libmap_disable)
|
|
lm_fini();
|
|
lock_release(rtld_bind_lock, &lockstate);
|
|
}
|
|
|
|
/*
|
|
* Iterate over a search path, translate each element, and invoke the
|
|
* callback on the result.
|
|
*/
|
|
static void *
|
|
path_enumerate(const char *path, path_enum_proc callback, void *arg)
|
|
{
|
|
const char *trans;
|
|
if (path == NULL)
|
|
return (NULL);
|
|
|
|
path += strspn(path, ":;");
|
|
while (*path != '\0') {
|
|
size_t len;
|
|
char *res;
|
|
|
|
len = strcspn(path, ":;");
|
|
trans = lm_findn(NULL, path, len);
|
|
if (trans)
|
|
res = callback(trans, strlen(trans), arg);
|
|
else
|
|
res = callback(path, len, arg);
|
|
|
|
if (res != NULL)
|
|
return (res);
|
|
|
|
path += len;
|
|
path += strspn(path, ":;");
|
|
}
|
|
|
|
return (NULL);
|
|
}
|
|
|
|
struct try_library_args {
|
|
const char *name;
|
|
size_t namelen;
|
|
char *buffer;
|
|
size_t buflen;
|
|
};
|
|
|
|
static void *
|
|
try_library_path(const char *dir, size_t dirlen, void *param)
|
|
{
|
|
struct try_library_args *arg;
|
|
|
|
arg = param;
|
|
if (*dir == '/' || trust) {
|
|
char *pathname;
|
|
|
|
if (dirlen + 1 + arg->namelen + 1 > arg->buflen)
|
|
return (NULL);
|
|
|
|
pathname = arg->buffer;
|
|
strncpy(pathname, dir, dirlen);
|
|
pathname[dirlen] = '/';
|
|
strcpy(pathname + dirlen + 1, arg->name);
|
|
|
|
dbg(" Trying \"%s\"", pathname);
|
|
if (access(pathname, F_OK) == 0) { /* We found it */
|
|
pathname = xmalloc(dirlen + 1 + arg->namelen + 1);
|
|
strcpy(pathname, arg->buffer);
|
|
return (pathname);
|
|
}
|
|
}
|
|
return (NULL);
|
|
}
|
|
|
|
static char *
|
|
search_library_path(const char *name, const char *path)
|
|
{
|
|
char *p;
|
|
struct try_library_args arg;
|
|
|
|
if (path == NULL)
|
|
return NULL;
|
|
|
|
arg.name = name;
|
|
arg.namelen = strlen(name);
|
|
arg.buffer = xmalloc(PATH_MAX);
|
|
arg.buflen = PATH_MAX;
|
|
|
|
p = path_enumerate(path, try_library_path, &arg);
|
|
|
|
free(arg.buffer);
|
|
|
|
return (p);
|
|
}
|
|
|
|
int
|
|
dlclose(void *handle)
|
|
{
|
|
Obj_Entry *root;
|
|
RtldLockState lockstate;
|
|
|
|
wlock_acquire(rtld_bind_lock, &lockstate);
|
|
root = dlcheck(handle);
|
|
if (root == NULL) {
|
|
lock_release(rtld_bind_lock, &lockstate);
|
|
return -1;
|
|
}
|
|
LD_UTRACE(UTRACE_DLCLOSE_START, handle, NULL, 0, root->dl_refcount,
|
|
root->path);
|
|
|
|
/* Unreference the object and its dependencies. */
|
|
root->dl_refcount--;
|
|
|
|
if (root->refcount == 1) {
|
|
/*
|
|
* The object will be no longer referenced, so we must unload it.
|
|
* First, call the fini functions.
|
|
*/
|
|
objlist_call_fini(&list_fini, root, &lockstate);
|
|
|
|
unref_dag(root);
|
|
|
|
/* Finish cleaning up the newly-unreferenced objects. */
|
|
GDB_STATE(RT_DELETE,&root->linkmap);
|
|
unload_object(root);
|
|
GDB_STATE(RT_CONSISTENT,NULL);
|
|
} else
|
|
unref_dag(root);
|
|
|
|
LD_UTRACE(UTRACE_DLCLOSE_STOP, handle, NULL, 0, 0, NULL);
|
|
lock_release(rtld_bind_lock, &lockstate);
|
|
return 0;
|
|
}
|
|
|
|
char *
|
|
dlerror(void)
|
|
{
|
|
char *msg = error_message;
|
|
error_message = NULL;
|
|
return msg;
|
|
}
|
|
|
|
/*
|
|
* This function is deprecated and has no effect.
|
|
*/
|
|
void
|
|
dllockinit(void *context,
|
|
void *(*lock_create)(void *context),
|
|
void (*rlock_acquire)(void *lock),
|
|
void (*wlock_acquire)(void *lock),
|
|
void (*lock_release)(void *lock),
|
|
void (*lock_destroy)(void *lock),
|
|
void (*context_destroy)(void *context))
|
|
{
|
|
static void *cur_context;
|
|
static void (*cur_context_destroy)(void *);
|
|
|
|
/* Just destroy the context from the previous call, if necessary. */
|
|
if (cur_context_destroy != NULL)
|
|
cur_context_destroy(cur_context);
|
|
cur_context = context;
|
|
cur_context_destroy = context_destroy;
|
|
}
|
|
|
|
void *
|
|
dlopen(const char *name, int mode)
|
|
{
|
|
|
|
return (rtld_dlopen(name, -1, mode));
|
|
}
|
|
|
|
void *
|
|
fdlopen(int fd, int mode)
|
|
{
|
|
|
|
return (rtld_dlopen(NULL, fd, mode));
|
|
}
|
|
|
|
static void *
|
|
rtld_dlopen(const char *name, int fd, int mode)
|
|
{
|
|
RtldLockState lockstate;
|
|
int lo_flags;
|
|
|
|
LD_UTRACE(UTRACE_DLOPEN_START, NULL, NULL, 0, mode, name);
|
|
ld_tracing = (mode & RTLD_TRACE) == 0 ? NULL : "1";
|
|
if (ld_tracing != NULL) {
|
|
rlock_acquire(rtld_bind_lock, &lockstate);
|
|
if (sigsetjmp(lockstate.env, 0) != 0)
|
|
lock_upgrade(rtld_bind_lock, &lockstate);
|
|
environ = (char **)*get_program_var_addr("environ", &lockstate);
|
|
lock_release(rtld_bind_lock, &lockstate);
|
|
}
|
|
lo_flags = RTLD_LO_DLOPEN;
|
|
if (mode & RTLD_NODELETE)
|
|
lo_flags |= RTLD_LO_NODELETE;
|
|
if (mode & RTLD_NOLOAD)
|
|
lo_flags |= RTLD_LO_NOLOAD;
|
|
if (ld_tracing != NULL)
|
|
lo_flags |= RTLD_LO_TRACE;
|
|
|
|
return (dlopen_object(name, fd, obj_main, lo_flags,
|
|
mode & (RTLD_MODEMASK | RTLD_GLOBAL), NULL));
|
|
}
|
|
|
|
static void
|
|
dlopen_cleanup(Obj_Entry *obj)
|
|
{
|
|
|
|
obj->dl_refcount--;
|
|
unref_dag(obj);
|
|
if (obj->refcount == 0)
|
|
unload_object(obj);
|
|
}
|
|
|
|
static Obj_Entry *
|
|
dlopen_object(const char *name, int fd, Obj_Entry *refobj, int lo_flags,
|
|
int mode, RtldLockState *lockstate)
|
|
{
|
|
Obj_Entry **old_obj_tail;
|
|
Obj_Entry *obj;
|
|
Objlist initlist;
|
|
RtldLockState mlockstate;
|
|
int result;
|
|
|
|
objlist_init(&initlist);
|
|
|
|
if (lockstate == NULL && !(lo_flags & RTLD_LO_EARLY)) {
|
|
wlock_acquire(rtld_bind_lock, &mlockstate);
|
|
lockstate = &mlockstate;
|
|
}
|
|
GDB_STATE(RT_ADD,NULL);
|
|
|
|
old_obj_tail = obj_tail;
|
|
obj = NULL;
|
|
if (name == NULL && fd == -1) {
|
|
obj = obj_main;
|
|
obj->refcount++;
|
|
} else {
|
|
obj = load_object(name, fd, refobj, lo_flags);
|
|
}
|
|
|
|
if (obj) {
|
|
obj->dl_refcount++;
|
|
if (mode & RTLD_GLOBAL && objlist_find(&list_global, obj) == NULL)
|
|
objlist_push_tail(&list_global, obj);
|
|
if (*old_obj_tail != NULL) { /* We loaded something new. */
|
|
assert(*old_obj_tail == obj);
|
|
result = load_needed_objects(obj,
|
|
lo_flags & (RTLD_LO_DLOPEN | RTLD_LO_EARLY));
|
|
init_dag(obj);
|
|
ref_dag(obj);
|
|
if (result != -1)
|
|
result = rtld_verify_versions(&obj->dagmembers);
|
|
if (result != -1 && ld_tracing)
|
|
goto trace;
|
|
if (result == -1 || relocate_object_dag(obj,
|
|
(mode & RTLD_MODEMASK) == RTLD_NOW, &obj_rtld,
|
|
(lo_flags & RTLD_LO_EARLY) ? SYMLOOK_EARLY : 0,
|
|
lockstate) == -1) {
|
|
dlopen_cleanup(obj);
|
|
obj = NULL;
|
|
} else if (lo_flags & RTLD_LO_EARLY) {
|
|
/*
|
|
* Do not call the init functions for early loaded
|
|
* filtees. The image is still not initialized enough
|
|
* for them to work.
|
|
*
|
|
* Our object is found by the global object list and
|
|
* will be ordered among all init calls done right
|
|
* before transferring control to main.
|
|
*/
|
|
} else {
|
|
/* Make list of init functions to call. */
|
|
initlist_add_objects(obj, &obj->next, &initlist);
|
|
}
|
|
/*
|
|
* Process all no_delete objects here, given them own
|
|
* DAGs to prevent their dependencies from being unloaded.
|
|
* This has to be done after we have loaded all of the
|
|
* dependencies, so that we do not miss any.
|
|
*/
|
|
if (obj != NULL)
|
|
process_nodelete(obj);
|
|
} else {
|
|
/*
|
|
* Bump the reference counts for objects on this DAG. If
|
|
* this is the first dlopen() call for the object that was
|
|
* already loaded as a dependency, initialize the dag
|
|
* starting at it.
|
|
*/
|
|
init_dag(obj);
|
|
ref_dag(obj);
|
|
|
|
if ((lo_flags & RTLD_LO_TRACE) != 0)
|
|
goto trace;
|
|
}
|
|
if (obj != NULL && ((lo_flags & RTLD_LO_NODELETE) != 0 ||
|
|
obj->z_nodelete) && !obj->ref_nodel) {
|
|
dbg("obj %s nodelete", obj->path);
|
|
ref_dag(obj);
|
|
obj->z_nodelete = obj->ref_nodel = true;
|
|
}
|
|
}
|
|
|
|
LD_UTRACE(UTRACE_DLOPEN_STOP, obj, NULL, 0, obj ? obj->dl_refcount : 0,
|
|
name);
|
|
GDB_STATE(RT_CONSISTENT,obj ? &obj->linkmap : NULL);
|
|
|
|
if (!(lo_flags & RTLD_LO_EARLY)) {
|
|
map_stacks_exec(lockstate);
|
|
}
|
|
|
|
if (initlist_objects_ifunc(&initlist, (mode & RTLD_MODEMASK) == RTLD_NOW,
|
|
(lo_flags & RTLD_LO_EARLY) ? SYMLOOK_EARLY : 0,
|
|
lockstate) == -1) {
|
|
objlist_clear(&initlist);
|
|
dlopen_cleanup(obj);
|
|
if (lockstate == &mlockstate)
|
|
lock_release(rtld_bind_lock, lockstate);
|
|
return (NULL);
|
|
}
|
|
|
|
if (!(lo_flags & RTLD_LO_EARLY)) {
|
|
/* Call the init functions. */
|
|
objlist_call_init(&initlist, lockstate);
|
|
}
|
|
objlist_clear(&initlist);
|
|
if (lockstate == &mlockstate)
|
|
lock_release(rtld_bind_lock, lockstate);
|
|
return obj;
|
|
trace:
|
|
trace_loaded_objects(obj);
|
|
if (lockstate == &mlockstate)
|
|
lock_release(rtld_bind_lock, lockstate);
|
|
exit(0);
|
|
}
|
|
|
|
static void *
|
|
do_dlsym(void *handle, const char *name, void *retaddr, const Ver_Entry *ve,
|
|
int flags)
|
|
{
|
|
DoneList donelist;
|
|
const Obj_Entry *obj, *defobj;
|
|
const Elf_Sym *def;
|
|
SymLook req;
|
|
RtldLockState lockstate;
|
|
#ifndef __ia64__
|
|
tls_index ti;
|
|
#endif
|
|
int res;
|
|
|
|
def = NULL;
|
|
defobj = NULL;
|
|
symlook_init(&req, name);
|
|
req.ventry = ve;
|
|
req.flags = flags | SYMLOOK_IN_PLT;
|
|
req.lockstate = &lockstate;
|
|
|
|
rlock_acquire(rtld_bind_lock, &lockstate);
|
|
if (sigsetjmp(lockstate.env, 0) != 0)
|
|
lock_upgrade(rtld_bind_lock, &lockstate);
|
|
if (handle == NULL || handle == RTLD_NEXT ||
|
|
handle == RTLD_DEFAULT || handle == RTLD_SELF) {
|
|
|
|
if ((obj = obj_from_addr(retaddr)) == NULL) {
|
|
_rtld_error("Cannot determine caller's shared object");
|
|
lock_release(rtld_bind_lock, &lockstate);
|
|
return NULL;
|
|
}
|
|
if (handle == NULL) { /* Just the caller's shared object. */
|
|
res = symlook_obj(&req, obj);
|
|
if (res == 0) {
|
|
def = req.sym_out;
|
|
defobj = req.defobj_out;
|
|
}
|
|
} else if (handle == RTLD_NEXT || /* Objects after caller's */
|
|
handle == RTLD_SELF) { /* ... caller included */
|
|
if (handle == RTLD_NEXT)
|
|
obj = obj->next;
|
|
for (; obj != NULL; obj = obj->next) {
|
|
res = symlook_obj(&req, obj);
|
|
if (res == 0) {
|
|
if (def == NULL ||
|
|
ELF_ST_BIND(req.sym_out->st_info) != STB_WEAK) {
|
|
def = req.sym_out;
|
|
defobj = req.defobj_out;
|
|
if (ELF_ST_BIND(def->st_info) != STB_WEAK)
|
|
break;
|
|
}
|
|
}
|
|
}
|
|
/*
|
|
* Search the dynamic linker itself, and possibly resolve the
|
|
* symbol from there. This is how the application links to
|
|
* dynamic linker services such as dlopen.
|
|
*/
|
|
if (def == NULL || ELF_ST_BIND(def->st_info) == STB_WEAK) {
|
|
res = symlook_obj(&req, &obj_rtld);
|
|
if (res == 0) {
|
|
def = req.sym_out;
|
|
defobj = req.defobj_out;
|
|
}
|
|
}
|
|
} else {
|
|
assert(handle == RTLD_DEFAULT);
|
|
res = symlook_default(&req, obj);
|
|
if (res == 0) {
|
|
defobj = req.defobj_out;
|
|
def = req.sym_out;
|
|
}
|
|
}
|
|
} else {
|
|
if ((obj = dlcheck(handle)) == NULL) {
|
|
lock_release(rtld_bind_lock, &lockstate);
|
|
return NULL;
|
|
}
|
|
|
|
donelist_init(&donelist);
|
|
if (obj->mainprog) {
|
|
/* Handle obtained by dlopen(NULL, ...) implies global scope. */
|
|
res = symlook_global(&req, &donelist);
|
|
if (res == 0) {
|
|
def = req.sym_out;
|
|
defobj = req.defobj_out;
|
|
}
|
|
/*
|
|
* Search the dynamic linker itself, and possibly resolve the
|
|
* symbol from there. This is how the application links to
|
|
* dynamic linker services such as dlopen.
|
|
*/
|
|
if (def == NULL || ELF_ST_BIND(def->st_info) == STB_WEAK) {
|
|
res = symlook_obj(&req, &obj_rtld);
|
|
if (res == 0) {
|
|
def = req.sym_out;
|
|
defobj = req.defobj_out;
|
|
}
|
|
}
|
|
}
|
|
else {
|
|
/* Search the whole DAG rooted at the given object. */
|
|
res = symlook_list(&req, &obj->dagmembers, &donelist);
|
|
if (res == 0) {
|
|
def = req.sym_out;
|
|
defobj = req.defobj_out;
|
|
}
|
|
}
|
|
}
|
|
|
|
if (def != NULL) {
|
|
lock_release(rtld_bind_lock, &lockstate);
|
|
|
|
/*
|
|
* The value required by the caller is derived from the value
|
|
* of the symbol. For the ia64 architecture, we need to
|
|
* construct a function descriptor which the caller can use to
|
|
* call the function with the right 'gp' value. For other
|
|
* architectures and for non-functions, the value is simply
|
|
* the relocated value of the symbol.
|
|
*/
|
|
if (ELF_ST_TYPE(def->st_info) == STT_FUNC)
|
|
return (make_function_pointer(def, defobj));
|
|
else if (ELF_ST_TYPE(def->st_info) == STT_GNU_IFUNC)
|
|
return (rtld_resolve_ifunc(defobj, def));
|
|
else if (ELF_ST_TYPE(def->st_info) == STT_TLS) {
|
|
#ifdef __ia64__
|
|
return (__tls_get_addr(defobj->tlsindex, def->st_value));
|
|
#else
|
|
ti.ti_module = defobj->tlsindex;
|
|
ti.ti_offset = def->st_value;
|
|
return (__tls_get_addr(&ti));
|
|
#endif
|
|
} else
|
|
return (defobj->relocbase + def->st_value);
|
|
}
|
|
|
|
_rtld_error("Undefined symbol \"%s\"", name);
|
|
lock_release(rtld_bind_lock, &lockstate);
|
|
return NULL;
|
|
}
|
|
|
|
void *
|
|
dlsym(void *handle, const char *name)
|
|
{
|
|
return do_dlsym(handle, name, __builtin_return_address(0), NULL,
|
|
SYMLOOK_DLSYM);
|
|
}
|
|
|
|
dlfunc_t
|
|
dlfunc(void *handle, const char *name)
|
|
{
|
|
union {
|
|
void *d;
|
|
dlfunc_t f;
|
|
} rv;
|
|
|
|
rv.d = do_dlsym(handle, name, __builtin_return_address(0), NULL,
|
|
SYMLOOK_DLSYM);
|
|
return (rv.f);
|
|
}
|
|
|
|
void *
|
|
dlvsym(void *handle, const char *name, const char *version)
|
|
{
|
|
Ver_Entry ventry;
|
|
|
|
ventry.name = version;
|
|
ventry.file = NULL;
|
|
ventry.hash = elf_hash(version);
|
|
ventry.flags= 0;
|
|
return do_dlsym(handle, name, __builtin_return_address(0), &ventry,
|
|
SYMLOOK_DLSYM);
|
|
}
|
|
|
|
int
|
|
_rtld_addr_phdr(const void *addr, struct dl_phdr_info *phdr_info)
|
|
{
|
|
const Obj_Entry *obj;
|
|
RtldLockState lockstate;
|
|
|
|
rlock_acquire(rtld_bind_lock, &lockstate);
|
|
obj = obj_from_addr(addr);
|
|
if (obj == NULL) {
|
|
_rtld_error("No shared object contains address");
|
|
lock_release(rtld_bind_lock, &lockstate);
|
|
return (0);
|
|
}
|
|
rtld_fill_dl_phdr_info(obj, phdr_info);
|
|
lock_release(rtld_bind_lock, &lockstate);
|
|
return (1);
|
|
}
|
|
|
|
int
|
|
dladdr(const void *addr, Dl_info *info)
|
|
{
|
|
const Obj_Entry *obj;
|
|
const Elf_Sym *def;
|
|
void *symbol_addr;
|
|
unsigned long symoffset;
|
|
RtldLockState lockstate;
|
|
|
|
rlock_acquire(rtld_bind_lock, &lockstate);
|
|
obj = obj_from_addr(addr);
|
|
if (obj == NULL) {
|
|
_rtld_error("No shared object contains address");
|
|
lock_release(rtld_bind_lock, &lockstate);
|
|
return 0;
|
|
}
|
|
info->dli_fname = obj->path;
|
|
info->dli_fbase = obj->mapbase;
|
|
info->dli_saddr = (void *)0;
|
|
info->dli_sname = NULL;
|
|
|
|
/*
|
|
* Walk the symbol list looking for the symbol whose address is
|
|
* closest to the address sent in.
|
|
*/
|
|
for (symoffset = 0; symoffset < obj->dynsymcount; symoffset++) {
|
|
def = obj->symtab + symoffset;
|
|
|
|
/*
|
|
* For skip the symbol if st_shndx is either SHN_UNDEF or
|
|
* SHN_COMMON.
|
|
*/
|
|
if (def->st_shndx == SHN_UNDEF || def->st_shndx == SHN_COMMON)
|
|
continue;
|
|
|
|
/*
|
|
* If the symbol is greater than the specified address, or if it
|
|
* is further away from addr than the current nearest symbol,
|
|
* then reject it.
|
|
*/
|
|
symbol_addr = obj->relocbase + def->st_value;
|
|
if (symbol_addr > addr || symbol_addr < info->dli_saddr)
|
|
continue;
|
|
|
|
/* Update our idea of the nearest symbol. */
|
|
info->dli_sname = obj->strtab + def->st_name;
|
|
info->dli_saddr = symbol_addr;
|
|
|
|
/* Exact match? */
|
|
if (info->dli_saddr == addr)
|
|
break;
|
|
}
|
|
lock_release(rtld_bind_lock, &lockstate);
|
|
return 1;
|
|
}
|
|
|
|
int
|
|
dlinfo(void *handle, int request, void *p)
|
|
{
|
|
const Obj_Entry *obj;
|
|
RtldLockState lockstate;
|
|
int error;
|
|
|
|
rlock_acquire(rtld_bind_lock, &lockstate);
|
|
|
|
if (handle == NULL || handle == RTLD_SELF) {
|
|
void *retaddr;
|
|
|
|
retaddr = __builtin_return_address(0); /* __GNUC__ only */
|
|
if ((obj = obj_from_addr(retaddr)) == NULL)
|
|
_rtld_error("Cannot determine caller's shared object");
|
|
} else
|
|
obj = dlcheck(handle);
|
|
|
|
if (obj == NULL) {
|
|
lock_release(rtld_bind_lock, &lockstate);
|
|
return (-1);
|
|
}
|
|
|
|
error = 0;
|
|
switch (request) {
|
|
case RTLD_DI_LINKMAP:
|
|
*((struct link_map const **)p) = &obj->linkmap;
|
|
break;
|
|
case RTLD_DI_ORIGIN:
|
|
error = rtld_dirname(obj->path, p);
|
|
break;
|
|
|
|
case RTLD_DI_SERINFOSIZE:
|
|
case RTLD_DI_SERINFO:
|
|
error = do_search_info(obj, request, (struct dl_serinfo *)p);
|
|
break;
|
|
|
|
default:
|
|
_rtld_error("Invalid request %d passed to dlinfo()", request);
|
|
error = -1;
|
|
}
|
|
|
|
lock_release(rtld_bind_lock, &lockstate);
|
|
|
|
return (error);
|
|
}
|
|
|
|
static void
|
|
rtld_fill_dl_phdr_info(const Obj_Entry *obj, struct dl_phdr_info *phdr_info)
|
|
{
|
|
|
|
phdr_info->dlpi_addr = (Elf_Addr)obj->relocbase;
|
|
phdr_info->dlpi_name = obj->path;
|
|
phdr_info->dlpi_phdr = obj->phdr;
|
|
phdr_info->dlpi_phnum = obj->phsize / sizeof(obj->phdr[0]);
|
|
phdr_info->dlpi_tls_modid = obj->tlsindex;
|
|
phdr_info->dlpi_tls_data = obj->tlsinit;
|
|
phdr_info->dlpi_adds = obj_loads;
|
|
phdr_info->dlpi_subs = obj_loads - obj_count;
|
|
}
|
|
|
|
int
|
|
dl_iterate_phdr(__dl_iterate_hdr_callback callback, void *param)
|
|
{
|
|
struct dl_phdr_info phdr_info;
|
|
const Obj_Entry *obj;
|
|
RtldLockState bind_lockstate, phdr_lockstate;
|
|
int error;
|
|
|
|
wlock_acquire(rtld_phdr_lock, &phdr_lockstate);
|
|
rlock_acquire(rtld_bind_lock, &bind_lockstate);
|
|
|
|
error = 0;
|
|
|
|
for (obj = obj_list; obj != NULL; obj = obj->next) {
|
|
rtld_fill_dl_phdr_info(obj, &phdr_info);
|
|
if ((error = callback(&phdr_info, sizeof phdr_info, param)) != 0)
|
|
break;
|
|
|
|
}
|
|
lock_release(rtld_bind_lock, &bind_lockstate);
|
|
lock_release(rtld_phdr_lock, &phdr_lockstate);
|
|
|
|
return (error);
|
|
}
|
|
|
|
static void *
|
|
fill_search_info(const char *dir, size_t dirlen, void *param)
|
|
{
|
|
struct fill_search_info_args *arg;
|
|
|
|
arg = param;
|
|
|
|
if (arg->request == RTLD_DI_SERINFOSIZE) {
|
|
arg->serinfo->dls_cnt ++;
|
|
arg->serinfo->dls_size += sizeof(struct dl_serpath) + dirlen + 1;
|
|
} else {
|
|
struct dl_serpath *s_entry;
|
|
|
|
s_entry = arg->serpath;
|
|
s_entry->dls_name = arg->strspace;
|
|
s_entry->dls_flags = arg->flags;
|
|
|
|
strncpy(arg->strspace, dir, dirlen);
|
|
arg->strspace[dirlen] = '\0';
|
|
|
|
arg->strspace += dirlen + 1;
|
|
arg->serpath++;
|
|
}
|
|
|
|
return (NULL);
|
|
}
|
|
|
|
static int
|
|
do_search_info(const Obj_Entry *obj, int request, struct dl_serinfo *info)
|
|
{
|
|
struct dl_serinfo _info;
|
|
struct fill_search_info_args args;
|
|
|
|
args.request = RTLD_DI_SERINFOSIZE;
|
|
args.serinfo = &_info;
|
|
|
|
_info.dls_size = __offsetof(struct dl_serinfo, dls_serpath);
|
|
_info.dls_cnt = 0;
|
|
|
|
path_enumerate(obj->rpath, fill_search_info, &args);
|
|
path_enumerate(ld_library_path, fill_search_info, &args);
|
|
path_enumerate(obj->runpath, fill_search_info, &args);
|
|
path_enumerate(gethints(obj->z_nodeflib), fill_search_info, &args);
|
|
if (!obj->z_nodeflib)
|
|
path_enumerate(STANDARD_LIBRARY_PATH, fill_search_info, &args);
|
|
|
|
|
|
if (request == RTLD_DI_SERINFOSIZE) {
|
|
info->dls_size = _info.dls_size;
|
|
info->dls_cnt = _info.dls_cnt;
|
|
return (0);
|
|
}
|
|
|
|
if (info->dls_cnt != _info.dls_cnt || info->dls_size != _info.dls_size) {
|
|
_rtld_error("Uninitialized Dl_serinfo struct passed to dlinfo()");
|
|
return (-1);
|
|
}
|
|
|
|
args.request = RTLD_DI_SERINFO;
|
|
args.serinfo = info;
|
|
args.serpath = &info->dls_serpath[0];
|
|
args.strspace = (char *)&info->dls_serpath[_info.dls_cnt];
|
|
|
|
args.flags = LA_SER_RUNPATH;
|
|
if (path_enumerate(obj->rpath, fill_search_info, &args) != NULL)
|
|
return (-1);
|
|
|
|
args.flags = LA_SER_LIBPATH;
|
|
if (path_enumerate(ld_library_path, fill_search_info, &args) != NULL)
|
|
return (-1);
|
|
|
|
args.flags = LA_SER_RUNPATH;
|
|
if (path_enumerate(obj->runpath, fill_search_info, &args) != NULL)
|
|
return (-1);
|
|
|
|
args.flags = LA_SER_CONFIG;
|
|
if (path_enumerate(gethints(obj->z_nodeflib), fill_search_info, &args)
|
|
!= NULL)
|
|
return (-1);
|
|
|
|
args.flags = LA_SER_DEFAULT;
|
|
if (!obj->z_nodeflib &&
|
|
path_enumerate(STANDARD_LIBRARY_PATH, fill_search_info, &args) != NULL)
|
|
return (-1);
|
|
return (0);
|
|
}
|
|
|
|
static int
|
|
rtld_dirname(const char *path, char *bname)
|
|
{
|
|
const char *endp;
|
|
|
|
/* Empty or NULL string gets treated as "." */
|
|
if (path == NULL || *path == '\0') {
|
|
bname[0] = '.';
|
|
bname[1] = '\0';
|
|
return (0);
|
|
}
|
|
|
|
/* Strip trailing slashes */
|
|
endp = path + strlen(path) - 1;
|
|
while (endp > path && *endp == '/')
|
|
endp--;
|
|
|
|
/* Find the start of the dir */
|
|
while (endp > path && *endp != '/')
|
|
endp--;
|
|
|
|
/* Either the dir is "/" or there are no slashes */
|
|
if (endp == path) {
|
|
bname[0] = *endp == '/' ? '/' : '.';
|
|
bname[1] = '\0';
|
|
return (0);
|
|
} else {
|
|
do {
|
|
endp--;
|
|
} while (endp > path && *endp == '/');
|
|
}
|
|
|
|
if (endp - path + 2 > PATH_MAX)
|
|
{
|
|
_rtld_error("Filename is too long: %s", path);
|
|
return(-1);
|
|
}
|
|
|
|
strncpy(bname, path, endp - path + 1);
|
|
bname[endp - path + 1] = '\0';
|
|
return (0);
|
|
}
|
|
|
|
static int
|
|
rtld_dirname_abs(const char *path, char *base)
|
|
{
|
|
char base_rel[PATH_MAX];
|
|
|
|
if (rtld_dirname(path, base) == -1)
|
|
return (-1);
|
|
if (base[0] == '/')
|
|
return (0);
|
|
if (getcwd(base_rel, sizeof(base_rel)) == NULL ||
|
|
strlcat(base_rel, "/", sizeof(base_rel)) >= sizeof(base_rel) ||
|
|
strlcat(base_rel, base, sizeof(base_rel)) >= sizeof(base_rel))
|
|
return (-1);
|
|
strcpy(base, base_rel);
|
|
return (0);
|
|
}
|
|
|
|
static void
|
|
linkmap_add(Obj_Entry *obj)
|
|
{
|
|
struct link_map *l = &obj->linkmap;
|
|
struct link_map *prev;
|
|
|
|
obj->linkmap.l_name = obj->path;
|
|
obj->linkmap.l_addr = obj->mapbase;
|
|
obj->linkmap.l_ld = obj->dynamic;
|
|
#ifdef __mips__
|
|
/* GDB needs load offset on MIPS to use the symbols */
|
|
obj->linkmap.l_offs = obj->relocbase;
|
|
#endif
|
|
|
|
if (r_debug.r_map == NULL) {
|
|
r_debug.r_map = l;
|
|
return;
|
|
}
|
|
|
|
/*
|
|
* Scan to the end of the list, but not past the entry for the
|
|
* dynamic linker, which we want to keep at the very end.
|
|
*/
|
|
for (prev = r_debug.r_map;
|
|
prev->l_next != NULL && prev->l_next != &obj_rtld.linkmap;
|
|
prev = prev->l_next)
|
|
;
|
|
|
|
/* Link in the new entry. */
|
|
l->l_prev = prev;
|
|
l->l_next = prev->l_next;
|
|
if (l->l_next != NULL)
|
|
l->l_next->l_prev = l;
|
|
prev->l_next = l;
|
|
}
|
|
|
|
static void
|
|
linkmap_delete(Obj_Entry *obj)
|
|
{
|
|
struct link_map *l = &obj->linkmap;
|
|
|
|
if (l->l_prev == NULL) {
|
|
if ((r_debug.r_map = l->l_next) != NULL)
|
|
l->l_next->l_prev = NULL;
|
|
return;
|
|
}
|
|
|
|
if ((l->l_prev->l_next = l->l_next) != NULL)
|
|
l->l_next->l_prev = l->l_prev;
|
|
}
|
|
|
|
/*
|
|
* Function for the debugger to set a breakpoint on to gain control.
|
|
*
|
|
* The two parameters allow the debugger to easily find and determine
|
|
* what the runtime loader is doing and to whom it is doing it.
|
|
*
|
|
* When the loadhook trap is hit (r_debug_state, set at program
|
|
* initialization), the arguments can be found on the stack:
|
|
*
|
|
* +8 struct link_map *m
|
|
* +4 struct r_debug *rd
|
|
* +0 RetAddr
|
|
*/
|
|
void
|
|
r_debug_state(struct r_debug* rd, struct link_map *m)
|
|
{
|
|
/*
|
|
* The following is a hack to force the compiler to emit calls to
|
|
* this function, even when optimizing. If the function is empty,
|
|
* the compiler is not obliged to emit any code for calls to it,
|
|
* even when marked __noinline. However, gdb depends on those
|
|
* calls being made.
|
|
*/
|
|
__compiler_membar();
|
|
}
|
|
|
|
/*
|
|
* A function called after init routines have completed. This can be used to
|
|
* break before a program's entry routine is called, and can be used when
|
|
* main is not available in the symbol table.
|
|
*/
|
|
void
|
|
_r_debug_postinit(struct link_map *m)
|
|
{
|
|
|
|
/* See r_debug_state(). */
|
|
__compiler_membar();
|
|
}
|
|
|
|
/*
|
|
* Get address of the pointer variable in the main program.
|
|
* Prefer non-weak symbol over the weak one.
|
|
*/
|
|
static const void **
|
|
get_program_var_addr(const char *name, RtldLockState *lockstate)
|
|
{
|
|
SymLook req;
|
|
DoneList donelist;
|
|
|
|
symlook_init(&req, name);
|
|
req.lockstate = lockstate;
|
|
donelist_init(&donelist);
|
|
if (symlook_global(&req, &donelist) != 0)
|
|
return (NULL);
|
|
if (ELF_ST_TYPE(req.sym_out->st_info) == STT_FUNC)
|
|
return ((const void **)make_function_pointer(req.sym_out,
|
|
req.defobj_out));
|
|
else if (ELF_ST_TYPE(req.sym_out->st_info) == STT_GNU_IFUNC)
|
|
return ((const void **)rtld_resolve_ifunc(req.defobj_out, req.sym_out));
|
|
else
|
|
return ((const void **)(req.defobj_out->relocbase +
|
|
req.sym_out->st_value));
|
|
}
|
|
|
|
/*
|
|
* Set a pointer variable in the main program to the given value. This
|
|
* is used to set key variables such as "environ" before any of the
|
|
* init functions are called.
|
|
*/
|
|
static void
|
|
set_program_var(const char *name, const void *value)
|
|
{
|
|
const void **addr;
|
|
|
|
if ((addr = get_program_var_addr(name, NULL)) != NULL) {
|
|
dbg("\"%s\": *%p <-- %p", name, addr, value);
|
|
*addr = value;
|
|
}
|
|
}
|
|
|
|
/*
|
|
* Search the global objects, including dependencies and main object,
|
|
* for the given symbol.
|
|
*/
|
|
static int
|
|
symlook_global(SymLook *req, DoneList *donelist)
|
|
{
|
|
SymLook req1;
|
|
const Objlist_Entry *elm;
|
|
int res;
|
|
|
|
symlook_init_from_req(&req1, req);
|
|
|
|
/* Search all objects loaded at program start up. */
|
|
if (req->defobj_out == NULL ||
|
|
ELF_ST_BIND(req->sym_out->st_info) == STB_WEAK) {
|
|
res = symlook_list(&req1, &list_main, donelist);
|
|
if (res == 0 && (req->defobj_out == NULL ||
|
|
ELF_ST_BIND(req1.sym_out->st_info) != STB_WEAK)) {
|
|
req->sym_out = req1.sym_out;
|
|
req->defobj_out = req1.defobj_out;
|
|
assert(req->defobj_out != NULL);
|
|
}
|
|
}
|
|
|
|
/* Search all DAGs whose roots are RTLD_GLOBAL objects. */
|
|
STAILQ_FOREACH(elm, &list_global, link) {
|
|
if (req->defobj_out != NULL &&
|
|
ELF_ST_BIND(req->sym_out->st_info) != STB_WEAK)
|
|
break;
|
|
res = symlook_list(&req1, &elm->obj->dagmembers, donelist);
|
|
if (res == 0 && (req->defobj_out == NULL ||
|
|
ELF_ST_BIND(req1.sym_out->st_info) != STB_WEAK)) {
|
|
req->sym_out = req1.sym_out;
|
|
req->defobj_out = req1.defobj_out;
|
|
assert(req->defobj_out != NULL);
|
|
}
|
|
}
|
|
|
|
return (req->sym_out != NULL ? 0 : ESRCH);
|
|
}
|
|
|
|
/*
|
|
* Given a symbol name in a referencing object, find the corresponding
|
|
* definition of the symbol. Returns a pointer to the symbol, or NULL if
|
|
* no definition was found. Returns a pointer to the Obj_Entry of the
|
|
* defining object via the reference parameter DEFOBJ_OUT.
|
|
*/
|
|
static int
|
|
symlook_default(SymLook *req, const Obj_Entry *refobj)
|
|
{
|
|
DoneList donelist;
|
|
const Objlist_Entry *elm;
|
|
SymLook req1;
|
|
int res;
|
|
|
|
donelist_init(&donelist);
|
|
symlook_init_from_req(&req1, req);
|
|
|
|
/* Look first in the referencing object if linked symbolically. */
|
|
if (refobj->symbolic && !donelist_check(&donelist, refobj)) {
|
|
res = symlook_obj(&req1, refobj);
|
|
if (res == 0) {
|
|
req->sym_out = req1.sym_out;
|
|
req->defobj_out = req1.defobj_out;
|
|
assert(req->defobj_out != NULL);
|
|
}
|
|
}
|
|
|
|
symlook_global(req, &donelist);
|
|
|
|
/* Search all dlopened DAGs containing the referencing object. */
|
|
STAILQ_FOREACH(elm, &refobj->dldags, link) {
|
|
if (req->sym_out != NULL &&
|
|
ELF_ST_BIND(req->sym_out->st_info) != STB_WEAK)
|
|
break;
|
|
res = symlook_list(&req1, &elm->obj->dagmembers, &donelist);
|
|
if (res == 0 && (req->sym_out == NULL ||
|
|
ELF_ST_BIND(req1.sym_out->st_info) != STB_WEAK)) {
|
|
req->sym_out = req1.sym_out;
|
|
req->defobj_out = req1.defobj_out;
|
|
assert(req->defobj_out != NULL);
|
|
}
|
|
}
|
|
|
|
/*
|
|
* Search the dynamic linker itself, and possibly resolve the
|
|
* symbol from there. This is how the application links to
|
|
* dynamic linker services such as dlopen.
|
|
*/
|
|
if (req->sym_out == NULL ||
|
|
ELF_ST_BIND(req->sym_out->st_info) == STB_WEAK) {
|
|
res = symlook_obj(&req1, &obj_rtld);
|
|
if (res == 0) {
|
|
req->sym_out = req1.sym_out;
|
|
req->defobj_out = req1.defobj_out;
|
|
assert(req->defobj_out != NULL);
|
|
}
|
|
}
|
|
|
|
return (req->sym_out != NULL ? 0 : ESRCH);
|
|
}
|
|
|
|
static int
|
|
symlook_list(SymLook *req, const Objlist *objlist, DoneList *dlp)
|
|
{
|
|
const Elf_Sym *def;
|
|
const Obj_Entry *defobj;
|
|
const Objlist_Entry *elm;
|
|
SymLook req1;
|
|
int res;
|
|
|
|
def = NULL;
|
|
defobj = NULL;
|
|
STAILQ_FOREACH(elm, objlist, link) {
|
|
if (donelist_check(dlp, elm->obj))
|
|
continue;
|
|
symlook_init_from_req(&req1, req);
|
|
if ((res = symlook_obj(&req1, elm->obj)) == 0) {
|
|
if (def == NULL || ELF_ST_BIND(req1.sym_out->st_info) != STB_WEAK) {
|
|
def = req1.sym_out;
|
|
defobj = req1.defobj_out;
|
|
if (ELF_ST_BIND(def->st_info) != STB_WEAK)
|
|
break;
|
|
}
|
|
}
|
|
}
|
|
if (def != NULL) {
|
|
req->sym_out = def;
|
|
req->defobj_out = defobj;
|
|
return (0);
|
|
}
|
|
return (ESRCH);
|
|
}
|
|
|
|
/*
|
|
* Search the chain of DAGS cointed to by the given Needed_Entry
|
|
* for a symbol of the given name. Each DAG is scanned completely
|
|
* before advancing to the next one. Returns a pointer to the symbol,
|
|
* or NULL if no definition was found.
|
|
*/
|
|
static int
|
|
symlook_needed(SymLook *req, const Needed_Entry *needed, DoneList *dlp)
|
|
{
|
|
const Elf_Sym *def;
|
|
const Needed_Entry *n;
|
|
const Obj_Entry *defobj;
|
|
SymLook req1;
|
|
int res;
|
|
|
|
def = NULL;
|
|
defobj = NULL;
|
|
symlook_init_from_req(&req1, req);
|
|
for (n = needed; n != NULL; n = n->next) {
|
|
if (n->obj == NULL ||
|
|
(res = symlook_list(&req1, &n->obj->dagmembers, dlp)) != 0)
|
|
continue;
|
|
if (def == NULL || ELF_ST_BIND(req1.sym_out->st_info) != STB_WEAK) {
|
|
def = req1.sym_out;
|
|
defobj = req1.defobj_out;
|
|
if (ELF_ST_BIND(def->st_info) != STB_WEAK)
|
|
break;
|
|
}
|
|
}
|
|
if (def != NULL) {
|
|
req->sym_out = def;
|
|
req->defobj_out = defobj;
|
|
return (0);
|
|
}
|
|
return (ESRCH);
|
|
}
|
|
|
|
/*
|
|
* Search the symbol table of a single shared object for a symbol of
|
|
* the given name and version, if requested. Returns a pointer to the
|
|
* symbol, or NULL if no definition was found. If the object is
|
|
* filter, return filtered symbol from filtee.
|
|
*
|
|
* The symbol's hash value is passed in for efficiency reasons; that
|
|
* eliminates many recomputations of the hash value.
|
|
*/
|
|
int
|
|
symlook_obj(SymLook *req, const Obj_Entry *obj)
|
|
{
|
|
DoneList donelist;
|
|
SymLook req1;
|
|
int flags, res, mres;
|
|
|
|
/*
|
|
* If there is at least one valid hash at this point, we prefer to
|
|
* use the faster GNU version if available.
|
|
*/
|
|
if (obj->valid_hash_gnu)
|
|
mres = symlook_obj1_gnu(req, obj);
|
|
else if (obj->valid_hash_sysv)
|
|
mres = symlook_obj1_sysv(req, obj);
|
|
else
|
|
return (EINVAL);
|
|
|
|
if (mres == 0) {
|
|
if (obj->needed_filtees != NULL) {
|
|
flags = (req->flags & SYMLOOK_EARLY) ? RTLD_LO_EARLY : 0;
|
|
load_filtees(__DECONST(Obj_Entry *, obj), flags, req->lockstate);
|
|
donelist_init(&donelist);
|
|
symlook_init_from_req(&req1, req);
|
|
res = symlook_needed(&req1, obj->needed_filtees, &donelist);
|
|
if (res == 0) {
|
|
req->sym_out = req1.sym_out;
|
|
req->defobj_out = req1.defobj_out;
|
|
}
|
|
return (res);
|
|
}
|
|
if (obj->needed_aux_filtees != NULL) {
|
|
flags = (req->flags & SYMLOOK_EARLY) ? RTLD_LO_EARLY : 0;
|
|
load_filtees(__DECONST(Obj_Entry *, obj), flags, req->lockstate);
|
|
donelist_init(&donelist);
|
|
symlook_init_from_req(&req1, req);
|
|
res = symlook_needed(&req1, obj->needed_aux_filtees, &donelist);
|
|
if (res == 0) {
|
|
req->sym_out = req1.sym_out;
|
|
req->defobj_out = req1.defobj_out;
|
|
return (res);
|
|
}
|
|
}
|
|
}
|
|
return (mres);
|
|
}
|
|
|
|
/* Symbol match routine common to both hash functions */
|
|
static bool
|
|
matched_symbol(SymLook *req, const Obj_Entry *obj, Sym_Match_Result *result,
|
|
const unsigned long symnum)
|
|
{
|
|
Elf_Versym verndx;
|
|
const Elf_Sym *symp;
|
|
const char *strp;
|
|
|
|
symp = obj->symtab + symnum;
|
|
strp = obj->strtab + symp->st_name;
|
|
|
|
switch (ELF_ST_TYPE(symp->st_info)) {
|
|
case STT_FUNC:
|
|
case STT_NOTYPE:
|
|
case STT_OBJECT:
|
|
case STT_COMMON:
|
|
case STT_GNU_IFUNC:
|
|
if (symp->st_value == 0)
|
|
return (false);
|
|
/* fallthrough */
|
|
case STT_TLS:
|
|
if (symp->st_shndx != SHN_UNDEF)
|
|
break;
|
|
#ifndef __mips__
|
|
else if (((req->flags & SYMLOOK_IN_PLT) == 0) &&
|
|
(ELF_ST_TYPE(symp->st_info) == STT_FUNC))
|
|
break;
|
|
/* fallthrough */
|
|
#endif
|
|
default:
|
|
return (false);
|
|
}
|
|
if (req->name[0] != strp[0] || strcmp(req->name, strp) != 0)
|
|
return (false);
|
|
|
|
if (req->ventry == NULL) {
|
|
if (obj->versyms != NULL) {
|
|
verndx = VER_NDX(obj->versyms[symnum]);
|
|
if (verndx > obj->vernum) {
|
|
_rtld_error(
|
|
"%s: symbol %s references wrong version %d",
|
|
obj->path, obj->strtab + symnum, verndx);
|
|
return (false);
|
|
}
|
|
/*
|
|
* If we are not called from dlsym (i.e. this
|
|
* is a normal relocation from unversioned
|
|
* binary), accept the symbol immediately if
|
|
* it happens to have first version after this
|
|
* shared object became versioned. Otherwise,
|
|
* if symbol is versioned and not hidden,
|
|
* remember it. If it is the only symbol with
|
|
* this name exported by the shared object, it
|
|
* will be returned as a match by the calling
|
|
* function. If symbol is global (verndx < 2)
|
|
* accept it unconditionally.
|
|
*/
|
|
if ((req->flags & SYMLOOK_DLSYM) == 0 &&
|
|
verndx == VER_NDX_GIVEN) {
|
|
result->sym_out = symp;
|
|
return (true);
|
|
}
|
|
else if (verndx >= VER_NDX_GIVEN) {
|
|
if ((obj->versyms[symnum] & VER_NDX_HIDDEN)
|
|
== 0) {
|
|
if (result->vsymp == NULL)
|
|
result->vsymp = symp;
|
|
result->vcount++;
|
|
}
|
|
return (false);
|
|
}
|
|
}
|
|
result->sym_out = symp;
|
|
return (true);
|
|
}
|
|
if (obj->versyms == NULL) {
|
|
if (object_match_name(obj, req->ventry->name)) {
|
|
_rtld_error("%s: object %s should provide version %s "
|
|
"for symbol %s", obj_rtld.path, obj->path,
|
|
req->ventry->name, obj->strtab + symnum);
|
|
return (false);
|
|
}
|
|
} else {
|
|
verndx = VER_NDX(obj->versyms[symnum]);
|
|
if (verndx > obj->vernum) {
|
|
_rtld_error("%s: symbol %s references wrong version %d",
|
|
obj->path, obj->strtab + symnum, verndx);
|
|
return (false);
|
|
}
|
|
if (obj->vertab[verndx].hash != req->ventry->hash ||
|
|
strcmp(obj->vertab[verndx].name, req->ventry->name)) {
|
|
/*
|
|
* Version does not match. Look if this is a
|
|
* global symbol and if it is not hidden. If
|
|
* global symbol (verndx < 2) is available,
|
|
* use it. Do not return symbol if we are
|
|
* called by dlvsym, because dlvsym looks for
|
|
* a specific version and default one is not
|
|
* what dlvsym wants.
|
|
*/
|
|
if ((req->flags & SYMLOOK_DLSYM) ||
|
|
(verndx >= VER_NDX_GIVEN) ||
|
|
(obj->versyms[symnum] & VER_NDX_HIDDEN))
|
|
return (false);
|
|
}
|
|
}
|
|
result->sym_out = symp;
|
|
return (true);
|
|
}
|
|
|
|
/*
|
|
* Search for symbol using SysV hash function.
|
|
* obj->buckets is known not to be NULL at this point; the test for this was
|
|
* performed with the obj->valid_hash_sysv assignment.
|
|
*/
|
|
static int
|
|
symlook_obj1_sysv(SymLook *req, const Obj_Entry *obj)
|
|
{
|
|
unsigned long symnum;
|
|
Sym_Match_Result matchres;
|
|
|
|
matchres.sym_out = NULL;
|
|
matchres.vsymp = NULL;
|
|
matchres.vcount = 0;
|
|
|
|
for (symnum = obj->buckets[req->hash % obj->nbuckets];
|
|
symnum != STN_UNDEF; symnum = obj->chains[symnum]) {
|
|
if (symnum >= obj->nchains)
|
|
return (ESRCH); /* Bad object */
|
|
|
|
if (matched_symbol(req, obj, &matchres, symnum)) {
|
|
req->sym_out = matchres.sym_out;
|
|
req->defobj_out = obj;
|
|
return (0);
|
|
}
|
|
}
|
|
if (matchres.vcount == 1) {
|
|
req->sym_out = matchres.vsymp;
|
|
req->defobj_out = obj;
|
|
return (0);
|
|
}
|
|
return (ESRCH);
|
|
}
|
|
|
|
/* Search for symbol using GNU hash function */
|
|
static int
|
|
symlook_obj1_gnu(SymLook *req, const Obj_Entry *obj)
|
|
{
|
|
Elf_Addr bloom_word;
|
|
const Elf32_Word *hashval;
|
|
Elf32_Word bucket;
|
|
Sym_Match_Result matchres;
|
|
unsigned int h1, h2;
|
|
unsigned long symnum;
|
|
|
|
matchres.sym_out = NULL;
|
|
matchres.vsymp = NULL;
|
|
matchres.vcount = 0;
|
|
|
|
/* Pick right bitmask word from Bloom filter array */
|
|
bloom_word = obj->bloom_gnu[(req->hash_gnu / __ELF_WORD_SIZE) &
|
|
obj->maskwords_bm_gnu];
|
|
|
|
/* Calculate modulus word size of gnu hash and its derivative */
|
|
h1 = req->hash_gnu & (__ELF_WORD_SIZE - 1);
|
|
h2 = ((req->hash_gnu >> obj->shift2_gnu) & (__ELF_WORD_SIZE - 1));
|
|
|
|
/* Filter out the "definitely not in set" queries */
|
|
if (((bloom_word >> h1) & (bloom_word >> h2) & 1) == 0)
|
|
return (ESRCH);
|
|
|
|
/* Locate hash chain and corresponding value element*/
|
|
bucket = obj->buckets_gnu[req->hash_gnu % obj->nbuckets_gnu];
|
|
if (bucket == 0)
|
|
return (ESRCH);
|
|
hashval = &obj->chain_zero_gnu[bucket];
|
|
do {
|
|
if (((*hashval ^ req->hash_gnu) >> 1) == 0) {
|
|
symnum = hashval - obj->chain_zero_gnu;
|
|
if (matched_symbol(req, obj, &matchres, symnum)) {
|
|
req->sym_out = matchres.sym_out;
|
|
req->defobj_out = obj;
|
|
return (0);
|
|
}
|
|
}
|
|
} while ((*hashval++ & 1) == 0);
|
|
if (matchres.vcount == 1) {
|
|
req->sym_out = matchres.vsymp;
|
|
req->defobj_out = obj;
|
|
return (0);
|
|
}
|
|
return (ESRCH);
|
|
}
|
|
|
|
static void
|
|
trace_loaded_objects(Obj_Entry *obj)
|
|
{
|
|
char *fmt1, *fmt2, *fmt, *main_local, *list_containers;
|
|
int c;
|
|
|
|
if ((main_local = getenv(LD_ "TRACE_LOADED_OBJECTS_PROGNAME")) == NULL)
|
|
main_local = "";
|
|
|
|
if ((fmt1 = getenv(LD_ "TRACE_LOADED_OBJECTS_FMT1")) == NULL)
|
|
fmt1 = "\t%o => %p (%x)\n";
|
|
|
|
if ((fmt2 = getenv(LD_ "TRACE_LOADED_OBJECTS_FMT2")) == NULL)
|
|
fmt2 = "\t%o (%x)\n";
|
|
|
|
list_containers = getenv(LD_ "TRACE_LOADED_OBJECTS_ALL");
|
|
|
|
for (; obj; obj = obj->next) {
|
|
Needed_Entry *needed;
|
|
char *name, *path;
|
|
bool is_lib;
|
|
|
|
if (list_containers && obj->needed != NULL)
|
|
rtld_printf("%s:\n", obj->path);
|
|
for (needed = obj->needed; needed; needed = needed->next) {
|
|
if (needed->obj != NULL) {
|
|
if (needed->obj->traced && !list_containers)
|
|
continue;
|
|
needed->obj->traced = true;
|
|
path = needed->obj->path;
|
|
} else
|
|
path = "not found";
|
|
|
|
name = (char *)obj->strtab + needed->name;
|
|
is_lib = strncmp(name, "lib", 3) == 0; /* XXX - bogus */
|
|
|
|
fmt = is_lib ? fmt1 : fmt2;
|
|
while ((c = *fmt++) != '\0') {
|
|
switch (c) {
|
|
default:
|
|
rtld_putchar(c);
|
|
continue;
|
|
case '\\':
|
|
switch (c = *fmt) {
|
|
case '\0':
|
|
continue;
|
|
case 'n':
|
|
rtld_putchar('\n');
|
|
break;
|
|
case 't':
|
|
rtld_putchar('\t');
|
|
break;
|
|
}
|
|
break;
|
|
case '%':
|
|
switch (c = *fmt) {
|
|
case '\0':
|
|
continue;
|
|
case '%':
|
|
default:
|
|
rtld_putchar(c);
|
|
break;
|
|
case 'A':
|
|
rtld_putstr(main_local);
|
|
break;
|
|
case 'a':
|
|
rtld_putstr(obj_main->path);
|
|
break;
|
|
case 'o':
|
|
rtld_putstr(name);
|
|
break;
|
|
#if 0
|
|
case 'm':
|
|
rtld_printf("%d", sodp->sod_major);
|
|
break;
|
|
case 'n':
|
|
rtld_printf("%d", sodp->sod_minor);
|
|
break;
|
|
#endif
|
|
case 'p':
|
|
rtld_putstr(path);
|
|
break;
|
|
case 'x':
|
|
rtld_printf("%p", needed->obj ? needed->obj->mapbase :
|
|
0);
|
|
break;
|
|
}
|
|
break;
|
|
}
|
|
++fmt;
|
|
}
|
|
}
|
|
}
|
|
}
|
|
|
|
/*
|
|
* Unload a dlopened object and its dependencies from memory and from
|
|
* our data structures. It is assumed that the DAG rooted in the
|
|
* object has already been unreferenced, and that the object has a
|
|
* reference count of 0.
|
|
*/
|
|
static void
|
|
unload_object(Obj_Entry *root)
|
|
{
|
|
Obj_Entry *obj;
|
|
Obj_Entry **linkp;
|
|
|
|
assert(root->refcount == 0);
|
|
|
|
/*
|
|
* Pass over the DAG removing unreferenced objects from
|
|
* appropriate lists.
|
|
*/
|
|
unlink_object(root);
|
|
|
|
/* Unmap all objects that are no longer referenced. */
|
|
linkp = &obj_list->next;
|
|
while ((obj = *linkp) != NULL) {
|
|
if (obj->refcount == 0) {
|
|
LD_UTRACE(UTRACE_UNLOAD_OBJECT, obj, obj->mapbase, obj->mapsize, 0,
|
|
obj->path);
|
|
dbg("unloading \"%s\"", obj->path);
|
|
unload_filtees(root);
|
|
munmap(obj->mapbase, obj->mapsize);
|
|
linkmap_delete(obj);
|
|
*linkp = obj->next;
|
|
obj_count--;
|
|
obj_free(obj);
|
|
} else
|
|
linkp = &obj->next;
|
|
}
|
|
obj_tail = linkp;
|
|
}
|
|
|
|
static void
|
|
unlink_object(Obj_Entry *root)
|
|
{
|
|
Objlist_Entry *elm;
|
|
|
|
if (root->refcount == 0) {
|
|
/* Remove the object from the RTLD_GLOBAL list. */
|
|
objlist_remove(&list_global, root);
|
|
|
|
/* Remove the object from all objects' DAG lists. */
|
|
STAILQ_FOREACH(elm, &root->dagmembers, link) {
|
|
objlist_remove(&elm->obj->dldags, root);
|
|
if (elm->obj != root)
|
|
unlink_object(elm->obj);
|
|
}
|
|
}
|
|
}
|
|
|
|
static void
|
|
ref_dag(Obj_Entry *root)
|
|
{
|
|
Objlist_Entry *elm;
|
|
|
|
assert(root->dag_inited);
|
|
STAILQ_FOREACH(elm, &root->dagmembers, link)
|
|
elm->obj->refcount++;
|
|
}
|
|
|
|
static void
|
|
unref_dag(Obj_Entry *root)
|
|
{
|
|
Objlist_Entry *elm;
|
|
|
|
assert(root->dag_inited);
|
|
STAILQ_FOREACH(elm, &root->dagmembers, link)
|
|
elm->obj->refcount--;
|
|
}
|
|
|
|
/*
|
|
* Common code for MD __tls_get_addr().
|
|
*/
|
|
static void *tls_get_addr_slow(Elf_Addr **, int, size_t) __noinline;
|
|
static void *
|
|
tls_get_addr_slow(Elf_Addr **dtvp, int index, size_t offset)
|
|
{
|
|
Elf_Addr *newdtv, *dtv;
|
|
RtldLockState lockstate;
|
|
int to_copy;
|
|
|
|
dtv = *dtvp;
|
|
/* Check dtv generation in case new modules have arrived */
|
|
if (dtv[0] != tls_dtv_generation) {
|
|
wlock_acquire(rtld_bind_lock, &lockstate);
|
|
newdtv = xcalloc(tls_max_index + 2, sizeof(Elf_Addr));
|
|
to_copy = dtv[1];
|
|
if (to_copy > tls_max_index)
|
|
to_copy = tls_max_index;
|
|
memcpy(&newdtv[2], &dtv[2], to_copy * sizeof(Elf_Addr));
|
|
newdtv[0] = tls_dtv_generation;
|
|
newdtv[1] = tls_max_index;
|
|
free(dtv);
|
|
lock_release(rtld_bind_lock, &lockstate);
|
|
dtv = *dtvp = newdtv;
|
|
}
|
|
|
|
/* Dynamically allocate module TLS if necessary */
|
|
if (dtv[index + 1] == 0) {
|
|
/* Signal safe, wlock will block out signals. */
|
|
wlock_acquire(rtld_bind_lock, &lockstate);
|
|
if (!dtv[index + 1])
|
|
dtv[index + 1] = (Elf_Addr)allocate_module_tls(index);
|
|
lock_release(rtld_bind_lock, &lockstate);
|
|
}
|
|
return ((void *)(dtv[index + 1] + offset));
|
|
}
|
|
|
|
void *
|
|
tls_get_addr_common(Elf_Addr **dtvp, int index, size_t offset)
|
|
{
|
|
Elf_Addr *dtv;
|
|
|
|
dtv = *dtvp;
|
|
/* Check dtv generation in case new modules have arrived */
|
|
if (__predict_true(dtv[0] == tls_dtv_generation &&
|
|
dtv[index + 1] != 0))
|
|
return ((void *)(dtv[index + 1] + offset));
|
|
return (tls_get_addr_slow(dtvp, index, offset));
|
|
}
|
|
|
|
#if defined(__arm__) || defined(__ia64__) || defined(__mips__) || defined(__powerpc__)
|
|
|
|
/*
|
|
* Allocate Static TLS using the Variant I method.
|
|
*/
|
|
void *
|
|
allocate_tls(Obj_Entry *objs, void *oldtcb, size_t tcbsize, size_t tcbalign)
|
|
{
|
|
Obj_Entry *obj;
|
|
char *tcb;
|
|
Elf_Addr **tls;
|
|
Elf_Addr *dtv;
|
|
Elf_Addr addr;
|
|
int i;
|
|
|
|
if (oldtcb != NULL && tcbsize == TLS_TCB_SIZE)
|
|
return (oldtcb);
|
|
|
|
assert(tcbsize >= TLS_TCB_SIZE);
|
|
tcb = xcalloc(1, tls_static_space - TLS_TCB_SIZE + tcbsize);
|
|
tls = (Elf_Addr **)(tcb + tcbsize - TLS_TCB_SIZE);
|
|
|
|
if (oldtcb != NULL) {
|
|
memcpy(tls, oldtcb, tls_static_space);
|
|
free(oldtcb);
|
|
|
|
/* Adjust the DTV. */
|
|
dtv = tls[0];
|
|
for (i = 0; i < dtv[1]; i++) {
|
|
if (dtv[i+2] >= (Elf_Addr)oldtcb &&
|
|
dtv[i+2] < (Elf_Addr)oldtcb + tls_static_space) {
|
|
dtv[i+2] = dtv[i+2] - (Elf_Addr)oldtcb + (Elf_Addr)tls;
|
|
}
|
|
}
|
|
} else {
|
|
dtv = xcalloc(tls_max_index + 2, sizeof(Elf_Addr));
|
|
tls[0] = dtv;
|
|
dtv[0] = tls_dtv_generation;
|
|
dtv[1] = tls_max_index;
|
|
|
|
for (obj = objs; obj; obj = obj->next) {
|
|
if (obj->tlsoffset > 0) {
|
|
addr = (Elf_Addr)tls + obj->tlsoffset;
|
|
if (obj->tlsinitsize > 0)
|
|
memcpy((void*) addr, obj->tlsinit, obj->tlsinitsize);
|
|
if (obj->tlssize > obj->tlsinitsize)
|
|
memset((void*) (addr + obj->tlsinitsize), 0,
|
|
obj->tlssize - obj->tlsinitsize);
|
|
dtv[obj->tlsindex + 1] = addr;
|
|
}
|
|
}
|
|
}
|
|
|
|
return (tcb);
|
|
}
|
|
|
|
void
|
|
free_tls(void *tcb, size_t tcbsize, size_t tcbalign)
|
|
{
|
|
Elf_Addr *dtv;
|
|
Elf_Addr tlsstart, tlsend;
|
|
int dtvsize, i;
|
|
|
|
assert(tcbsize >= TLS_TCB_SIZE);
|
|
|
|
tlsstart = (Elf_Addr)tcb + tcbsize - TLS_TCB_SIZE;
|
|
tlsend = tlsstart + tls_static_space;
|
|
|
|
dtv = *(Elf_Addr **)tlsstart;
|
|
dtvsize = dtv[1];
|
|
for (i = 0; i < dtvsize; i++) {
|
|
if (dtv[i+2] && (dtv[i+2] < tlsstart || dtv[i+2] >= tlsend)) {
|
|
free((void*)dtv[i+2]);
|
|
}
|
|
}
|
|
free(dtv);
|
|
free(tcb);
|
|
}
|
|
|
|
#endif
|
|
|
|
#if defined(__i386__) || defined(__amd64__) || defined(__sparc64__)
|
|
|
|
/*
|
|
* Allocate Static TLS using the Variant II method.
|
|
*/
|
|
void *
|
|
allocate_tls(Obj_Entry *objs, void *oldtls, size_t tcbsize, size_t tcbalign)
|
|
{
|
|
Obj_Entry *obj;
|
|
size_t size, ralign;
|
|
char *tls;
|
|
Elf_Addr *dtv, *olddtv;
|
|
Elf_Addr segbase, oldsegbase, addr;
|
|
int i;
|
|
|
|
ralign = tcbalign;
|
|
if (tls_static_max_align > ralign)
|
|
ralign = tls_static_max_align;
|
|
size = round(tls_static_space, ralign) + round(tcbsize, ralign);
|
|
|
|
assert(tcbsize >= 2*sizeof(Elf_Addr));
|
|
tls = malloc_aligned(size, ralign);
|
|
dtv = xcalloc(tls_max_index + 2, sizeof(Elf_Addr));
|
|
|
|
segbase = (Elf_Addr)(tls + round(tls_static_space, ralign));
|
|
((Elf_Addr*)segbase)[0] = segbase;
|
|
((Elf_Addr*)segbase)[1] = (Elf_Addr) dtv;
|
|
|
|
dtv[0] = tls_dtv_generation;
|
|
dtv[1] = tls_max_index;
|
|
|
|
if (oldtls) {
|
|
/*
|
|
* Copy the static TLS block over whole.
|
|
*/
|
|
oldsegbase = (Elf_Addr) oldtls;
|
|
memcpy((void *)(segbase - tls_static_space),
|
|
(const void *)(oldsegbase - tls_static_space),
|
|
tls_static_space);
|
|
|
|
/*
|
|
* If any dynamic TLS blocks have been created tls_get_addr(),
|
|
* move them over.
|
|
*/
|
|
olddtv = ((Elf_Addr**)oldsegbase)[1];
|
|
for (i = 0; i < olddtv[1]; i++) {
|
|
if (olddtv[i+2] < oldsegbase - size || olddtv[i+2] > oldsegbase) {
|
|
dtv[i+2] = olddtv[i+2];
|
|
olddtv[i+2] = 0;
|
|
}
|
|
}
|
|
|
|
/*
|
|
* We assume that this block was the one we created with
|
|
* allocate_initial_tls().
|
|
*/
|
|
free_tls(oldtls, 2*sizeof(Elf_Addr), sizeof(Elf_Addr));
|
|
} else {
|
|
for (obj = objs; obj; obj = obj->next) {
|
|
if (obj->tlsoffset) {
|
|
addr = segbase - obj->tlsoffset;
|
|
memset((void*) (addr + obj->tlsinitsize),
|
|
0, obj->tlssize - obj->tlsinitsize);
|
|
if (obj->tlsinit)
|
|
memcpy((void*) addr, obj->tlsinit, obj->tlsinitsize);
|
|
dtv[obj->tlsindex + 1] = addr;
|
|
}
|
|
}
|
|
}
|
|
|
|
return (void*) segbase;
|
|
}
|
|
|
|
void
|
|
free_tls(void *tls, size_t tcbsize, size_t tcbalign)
|
|
{
|
|
Elf_Addr* dtv;
|
|
size_t size, ralign;
|
|
int dtvsize, i;
|
|
Elf_Addr tlsstart, tlsend;
|
|
|
|
/*
|
|
* Figure out the size of the initial TLS block so that we can
|
|
* find stuff which ___tls_get_addr() allocated dynamically.
|
|
*/
|
|
ralign = tcbalign;
|
|
if (tls_static_max_align > ralign)
|
|
ralign = tls_static_max_align;
|
|
size = round(tls_static_space, ralign);
|
|
|
|
dtv = ((Elf_Addr**)tls)[1];
|
|
dtvsize = dtv[1];
|
|
tlsend = (Elf_Addr) tls;
|
|
tlsstart = tlsend - size;
|
|
for (i = 0; i < dtvsize; i++) {
|
|
if (dtv[i + 2] != 0 && (dtv[i + 2] < tlsstart || dtv[i + 2] > tlsend)) {
|
|
free_aligned((void *)dtv[i + 2]);
|
|
}
|
|
}
|
|
|
|
free_aligned((void *)tlsstart);
|
|
free((void*) dtv);
|
|
}
|
|
|
|
#endif
|
|
|
|
/*
|
|
* Allocate TLS block for module with given index.
|
|
*/
|
|
void *
|
|
allocate_module_tls(int index)
|
|
{
|
|
Obj_Entry* obj;
|
|
char* p;
|
|
|
|
for (obj = obj_list; obj; obj = obj->next) {
|
|
if (obj->tlsindex == index)
|
|
break;
|
|
}
|
|
if (!obj) {
|
|
_rtld_error("Can't find module with TLS index %d", index);
|
|
die();
|
|
}
|
|
|
|
p = malloc_aligned(obj->tlssize, obj->tlsalign);
|
|
memcpy(p, obj->tlsinit, obj->tlsinitsize);
|
|
memset(p + obj->tlsinitsize, 0, obj->tlssize - obj->tlsinitsize);
|
|
|
|
return p;
|
|
}
|
|
|
|
bool
|
|
allocate_tls_offset(Obj_Entry *obj)
|
|
{
|
|
size_t off;
|
|
|
|
if (obj->tls_done)
|
|
return true;
|
|
|
|
if (obj->tlssize == 0) {
|
|
obj->tls_done = true;
|
|
return true;
|
|
}
|
|
|
|
if (obj->tlsindex == 1)
|
|
off = calculate_first_tls_offset(obj->tlssize, obj->tlsalign);
|
|
else
|
|
off = calculate_tls_offset(tls_last_offset, tls_last_size,
|
|
obj->tlssize, obj->tlsalign);
|
|
|
|
/*
|
|
* If we have already fixed the size of the static TLS block, we
|
|
* must stay within that size. When allocating the static TLS, we
|
|
* leave a small amount of space spare to be used for dynamically
|
|
* loading modules which use static TLS.
|
|
*/
|
|
if (tls_static_space != 0) {
|
|
if (calculate_tls_end(off, obj->tlssize) > tls_static_space)
|
|
return false;
|
|
} else if (obj->tlsalign > tls_static_max_align) {
|
|
tls_static_max_align = obj->tlsalign;
|
|
}
|
|
|
|
tls_last_offset = obj->tlsoffset = off;
|
|
tls_last_size = obj->tlssize;
|
|
obj->tls_done = true;
|
|
|
|
return true;
|
|
}
|
|
|
|
void
|
|
free_tls_offset(Obj_Entry *obj)
|
|
{
|
|
|
|
/*
|
|
* If we were the last thing to allocate out of the static TLS
|
|
* block, we give our space back to the 'allocator'. This is a
|
|
* simplistic workaround to allow libGL.so.1 to be loaded and
|
|
* unloaded multiple times.
|
|
*/
|
|
if (calculate_tls_end(obj->tlsoffset, obj->tlssize)
|
|
== calculate_tls_end(tls_last_offset, tls_last_size)) {
|
|
tls_last_offset -= obj->tlssize;
|
|
tls_last_size = 0;
|
|
}
|
|
}
|
|
|
|
void *
|
|
_rtld_allocate_tls(void *oldtls, size_t tcbsize, size_t tcbalign)
|
|
{
|
|
void *ret;
|
|
RtldLockState lockstate;
|
|
|
|
wlock_acquire(rtld_bind_lock, &lockstate);
|
|
ret = allocate_tls(obj_list, oldtls, tcbsize, tcbalign);
|
|
lock_release(rtld_bind_lock, &lockstate);
|
|
return (ret);
|
|
}
|
|
|
|
void
|
|
_rtld_free_tls(void *tcb, size_t tcbsize, size_t tcbalign)
|
|
{
|
|
RtldLockState lockstate;
|
|
|
|
wlock_acquire(rtld_bind_lock, &lockstate);
|
|
free_tls(tcb, tcbsize, tcbalign);
|
|
lock_release(rtld_bind_lock, &lockstate);
|
|
}
|
|
|
|
static void
|
|
object_add_name(Obj_Entry *obj, const char *name)
|
|
{
|
|
Name_Entry *entry;
|
|
size_t len;
|
|
|
|
len = strlen(name);
|
|
entry = malloc(sizeof(Name_Entry) + len);
|
|
|
|
if (entry != NULL) {
|
|
strcpy(entry->name, name);
|
|
STAILQ_INSERT_TAIL(&obj->names, entry, link);
|
|
}
|
|
}
|
|
|
|
static int
|
|
object_match_name(const Obj_Entry *obj, const char *name)
|
|
{
|
|
Name_Entry *entry;
|
|
|
|
STAILQ_FOREACH(entry, &obj->names, link) {
|
|
if (strcmp(name, entry->name) == 0)
|
|
return (1);
|
|
}
|
|
return (0);
|
|
}
|
|
|
|
static Obj_Entry *
|
|
locate_dependency(const Obj_Entry *obj, const char *name)
|
|
{
|
|
const Objlist_Entry *entry;
|
|
const Needed_Entry *needed;
|
|
|
|
STAILQ_FOREACH(entry, &list_main, link) {
|
|
if (object_match_name(entry->obj, name))
|
|
return entry->obj;
|
|
}
|
|
|
|
for (needed = obj->needed; needed != NULL; needed = needed->next) {
|
|
if (strcmp(obj->strtab + needed->name, name) == 0 ||
|
|
(needed->obj != NULL && object_match_name(needed->obj, name))) {
|
|
/*
|
|
* If there is DT_NEEDED for the name we are looking for,
|
|
* we are all set. Note that object might not be found if
|
|
* dependency was not loaded yet, so the function can
|
|
* return NULL here. This is expected and handled
|
|
* properly by the caller.
|
|
*/
|
|
return (needed->obj);
|
|
}
|
|
}
|
|
_rtld_error("%s: Unexpected inconsistency: dependency %s not found",
|
|
obj->path, name);
|
|
die();
|
|
}
|
|
|
|
static int
|
|
check_object_provided_version(Obj_Entry *refobj, const Obj_Entry *depobj,
|
|
const Elf_Vernaux *vna)
|
|
{
|
|
const Elf_Verdef *vd;
|
|
const char *vername;
|
|
|
|
vername = refobj->strtab + vna->vna_name;
|
|
vd = depobj->verdef;
|
|
if (vd == NULL) {
|
|
_rtld_error("%s: version %s required by %s not defined",
|
|
depobj->path, vername, refobj->path);
|
|
return (-1);
|
|
}
|
|
for (;;) {
|
|
if (vd->vd_version != VER_DEF_CURRENT) {
|
|
_rtld_error("%s: Unsupported version %d of Elf_Verdef entry",
|
|
depobj->path, vd->vd_version);
|
|
return (-1);
|
|
}
|
|
if (vna->vna_hash == vd->vd_hash) {
|
|
const Elf_Verdaux *aux = (const Elf_Verdaux *)
|
|
((char *)vd + vd->vd_aux);
|
|
if (strcmp(vername, depobj->strtab + aux->vda_name) == 0)
|
|
return (0);
|
|
}
|
|
if (vd->vd_next == 0)
|
|
break;
|
|
vd = (const Elf_Verdef *) ((char *)vd + vd->vd_next);
|
|
}
|
|
if (vna->vna_flags & VER_FLG_WEAK)
|
|
return (0);
|
|
_rtld_error("%s: version %s required by %s not found",
|
|
depobj->path, vername, refobj->path);
|
|
return (-1);
|
|
}
|
|
|
|
static int
|
|
rtld_verify_object_versions(Obj_Entry *obj)
|
|
{
|
|
const Elf_Verneed *vn;
|
|
const Elf_Verdef *vd;
|
|
const Elf_Verdaux *vda;
|
|
const Elf_Vernaux *vna;
|
|
const Obj_Entry *depobj;
|
|
int maxvernum, vernum;
|
|
|
|
if (obj->ver_checked)
|
|
return (0);
|
|
obj->ver_checked = true;
|
|
|
|
maxvernum = 0;
|
|
/*
|
|
* Walk over defined and required version records and figure out
|
|
* max index used by any of them. Do very basic sanity checking
|
|
* while there.
|
|
*/
|
|
vn = obj->verneed;
|
|
while (vn != NULL) {
|
|
if (vn->vn_version != VER_NEED_CURRENT) {
|
|
_rtld_error("%s: Unsupported version %d of Elf_Verneed entry",
|
|
obj->path, vn->vn_version);
|
|
return (-1);
|
|
}
|
|
vna = (const Elf_Vernaux *) ((char *)vn + vn->vn_aux);
|
|
for (;;) {
|
|
vernum = VER_NEED_IDX(vna->vna_other);
|
|
if (vernum > maxvernum)
|
|
maxvernum = vernum;
|
|
if (vna->vna_next == 0)
|
|
break;
|
|
vna = (const Elf_Vernaux *) ((char *)vna + vna->vna_next);
|
|
}
|
|
if (vn->vn_next == 0)
|
|
break;
|
|
vn = (const Elf_Verneed *) ((char *)vn + vn->vn_next);
|
|
}
|
|
|
|
vd = obj->verdef;
|
|
while (vd != NULL) {
|
|
if (vd->vd_version != VER_DEF_CURRENT) {
|
|
_rtld_error("%s: Unsupported version %d of Elf_Verdef entry",
|
|
obj->path, vd->vd_version);
|
|
return (-1);
|
|
}
|
|
vernum = VER_DEF_IDX(vd->vd_ndx);
|
|
if (vernum > maxvernum)
|
|
maxvernum = vernum;
|
|
if (vd->vd_next == 0)
|
|
break;
|
|
vd = (const Elf_Verdef *) ((char *)vd + vd->vd_next);
|
|
}
|
|
|
|
if (maxvernum == 0)
|
|
return (0);
|
|
|
|
/*
|
|
* Store version information in array indexable by version index.
|
|
* Verify that object version requirements are satisfied along the
|
|
* way.
|
|
*/
|
|
obj->vernum = maxvernum + 1;
|
|
obj->vertab = xcalloc(obj->vernum, sizeof(Ver_Entry));
|
|
|
|
vd = obj->verdef;
|
|
while (vd != NULL) {
|
|
if ((vd->vd_flags & VER_FLG_BASE) == 0) {
|
|
vernum = VER_DEF_IDX(vd->vd_ndx);
|
|
assert(vernum <= maxvernum);
|
|
vda = (const Elf_Verdaux *)((char *)vd + vd->vd_aux);
|
|
obj->vertab[vernum].hash = vd->vd_hash;
|
|
obj->vertab[vernum].name = obj->strtab + vda->vda_name;
|
|
obj->vertab[vernum].file = NULL;
|
|
obj->vertab[vernum].flags = 0;
|
|
}
|
|
if (vd->vd_next == 0)
|
|
break;
|
|
vd = (const Elf_Verdef *) ((char *)vd + vd->vd_next);
|
|
}
|
|
|
|
vn = obj->verneed;
|
|
while (vn != NULL) {
|
|
depobj = locate_dependency(obj, obj->strtab + vn->vn_file);
|
|
if (depobj == NULL)
|
|
return (-1);
|
|
vna = (const Elf_Vernaux *) ((char *)vn + vn->vn_aux);
|
|
for (;;) {
|
|
if (check_object_provided_version(obj, depobj, vna))
|
|
return (-1);
|
|
vernum = VER_NEED_IDX(vna->vna_other);
|
|
assert(vernum <= maxvernum);
|
|
obj->vertab[vernum].hash = vna->vna_hash;
|
|
obj->vertab[vernum].name = obj->strtab + vna->vna_name;
|
|
obj->vertab[vernum].file = obj->strtab + vn->vn_file;
|
|
obj->vertab[vernum].flags = (vna->vna_other & VER_NEED_HIDDEN) ?
|
|
VER_INFO_HIDDEN : 0;
|
|
if (vna->vna_next == 0)
|
|
break;
|
|
vna = (const Elf_Vernaux *) ((char *)vna + vna->vna_next);
|
|
}
|
|
if (vn->vn_next == 0)
|
|
break;
|
|
vn = (const Elf_Verneed *) ((char *)vn + vn->vn_next);
|
|
}
|
|
return 0;
|
|
}
|
|
|
|
static int
|
|
rtld_verify_versions(const Objlist *objlist)
|
|
{
|
|
Objlist_Entry *entry;
|
|
int rc;
|
|
|
|
rc = 0;
|
|
STAILQ_FOREACH(entry, objlist, link) {
|
|
/*
|
|
* Skip dummy objects or objects that have their version requirements
|
|
* already checked.
|
|
*/
|
|
if (entry->obj->strtab == NULL || entry->obj->vertab != NULL)
|
|
continue;
|
|
if (rtld_verify_object_versions(entry->obj) == -1) {
|
|
rc = -1;
|
|
if (ld_tracing == NULL)
|
|
break;
|
|
}
|
|
}
|
|
if (rc == 0 || ld_tracing != NULL)
|
|
rc = rtld_verify_object_versions(&obj_rtld);
|
|
return rc;
|
|
}
|
|
|
|
const Ver_Entry *
|
|
fetch_ventry(const Obj_Entry *obj, unsigned long symnum)
|
|
{
|
|
Elf_Versym vernum;
|
|
|
|
if (obj->vertab) {
|
|
vernum = VER_NDX(obj->versyms[symnum]);
|
|
if (vernum >= obj->vernum) {
|
|
_rtld_error("%s: symbol %s has wrong verneed value %d",
|
|
obj->path, obj->strtab + symnum, vernum);
|
|
} else if (obj->vertab[vernum].hash != 0) {
|
|
return &obj->vertab[vernum];
|
|
}
|
|
}
|
|
return NULL;
|
|
}
|
|
|
|
int
|
|
_rtld_get_stack_prot(void)
|
|
{
|
|
|
|
return (stack_prot);
|
|
}
|
|
|
|
int
|
|
_rtld_is_dlopened(void *arg)
|
|
{
|
|
Obj_Entry *obj;
|
|
RtldLockState lockstate;
|
|
int res;
|
|
|
|
rlock_acquire(rtld_bind_lock, &lockstate);
|
|
obj = dlcheck(arg);
|
|
if (obj == NULL)
|
|
obj = obj_from_addr(arg);
|
|
if (obj == NULL) {
|
|
_rtld_error("No shared object contains address");
|
|
lock_release(rtld_bind_lock, &lockstate);
|
|
return (-1);
|
|
}
|
|
res = obj->dlopened ? 1 : 0;
|
|
lock_release(rtld_bind_lock, &lockstate);
|
|
return (res);
|
|
}
|
|
|
|
static void
|
|
map_stacks_exec(RtldLockState *lockstate)
|
|
{
|
|
void (*thr_map_stacks_exec)(void);
|
|
|
|
if ((max_stack_flags & PF_X) == 0 || (stack_prot & PROT_EXEC) != 0)
|
|
return;
|
|
thr_map_stacks_exec = (void (*)(void))(uintptr_t)
|
|
get_program_var_addr("__pthread_map_stacks_exec", lockstate);
|
|
if (thr_map_stacks_exec != NULL) {
|
|
stack_prot |= PROT_EXEC;
|
|
thr_map_stacks_exec();
|
|
}
|
|
}
|
|
|
|
void
|
|
symlook_init(SymLook *dst, const char *name)
|
|
{
|
|
|
|
bzero(dst, sizeof(*dst));
|
|
dst->name = name;
|
|
dst->hash = elf_hash(name);
|
|
dst->hash_gnu = gnu_hash(name);
|
|
}
|
|
|
|
static void
|
|
symlook_init_from_req(SymLook *dst, const SymLook *src)
|
|
{
|
|
|
|
dst->name = src->name;
|
|
dst->hash = src->hash;
|
|
dst->hash_gnu = src->hash_gnu;
|
|
dst->ventry = src->ventry;
|
|
dst->flags = src->flags;
|
|
dst->defobj_out = NULL;
|
|
dst->sym_out = NULL;
|
|
dst->lockstate = src->lockstate;
|
|
}
|
|
|
|
/*
|
|
* Overrides for libc_pic-provided functions.
|
|
*/
|
|
|
|
int
|
|
__getosreldate(void)
|
|
{
|
|
size_t len;
|
|
int oid[2];
|
|
int error, osrel;
|
|
|
|
if (osreldate != 0)
|
|
return (osreldate);
|
|
|
|
oid[0] = CTL_KERN;
|
|
oid[1] = KERN_OSRELDATE;
|
|
osrel = 0;
|
|
len = sizeof(osrel);
|
|
error = sysctl(oid, 2, &osrel, &len, NULL, 0);
|
|
if (error == 0 && osrel > 0 && len == sizeof(osrel))
|
|
osreldate = osrel;
|
|
return (osreldate);
|
|
}
|
|
|
|
void
|
|
exit(int status)
|
|
{
|
|
|
|
_exit(status);
|
|
}
|
|
|
|
void (*__cleanup)(void);
|
|
int __isthreaded = 0;
|
|
int _thread_autoinit_dummy_decl = 1;
|
|
|
|
/*
|
|
* No unresolved symbols for rtld.
|
|
*/
|
|
void
|
|
__pthread_cxa_finalize(struct dl_phdr_info *a)
|
|
{
|
|
}
|
|
|
|
void
|
|
__stack_chk_fail(void)
|
|
{
|
|
|
|
_rtld_error("stack overflow detected; terminated");
|
|
die();
|
|
}
|
|
__weak_reference(__stack_chk_fail, __stack_chk_fail_local);
|
|
|
|
void
|
|
__chk_fail(void)
|
|
{
|
|
|
|
_rtld_error("buffer overflow detected; terminated");
|
|
die();
|
|
}
|
|
|
|
const char *
|
|
rtld_strerror(int errnum)
|
|
{
|
|
|
|
if (errnum < 0 || errnum >= sys_nerr)
|
|
return ("Unknown error");
|
|
return (sys_errlist[errnum]);
|
|
}
|