rtld.c revision 212497
11590Srgrimes/*- 21590Srgrimes * Copyright 1996, 1997, 1998, 1999, 2000 John D. Polstra. 31590Srgrimes * Copyright 2003 Alexander Kabaev <kan@FreeBSD.ORG>. 489615Sdes * All rights reserved. 589615Sdes * 61590Srgrimes * Redistribution and use in source and binary forms, with or without 789615Sdes * modification, are permitted provided that the following conditions 889615Sdes * are met: 989615Sdes * 1. Redistributions of source code must retain the above copyright 1089615Sdes * notice, this list of conditions and the following disclaimer. 1189615Sdes * 2. Redistributions in binary form must reproduce the above copyright 121590Srgrimes * notice, this list of conditions and the following disclaimer in the 131590Srgrimes * documentation and/or other materials provided with the distribution. 141590Srgrimes * 151590Srgrimes * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR 161590Srgrimes * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES 171590Srgrimes * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. 181590Srgrimes * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, 191590Srgrimes * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT 201590Srgrimes * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 211590Srgrimes * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 221590Srgrimes * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 231590Srgrimes * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF 241590Srgrimes * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 251590Srgrimes * 261590Srgrimes * $FreeBSD: head/libexec/rtld-elf/rtld.c 212497 2010-09-12 17:04:51Z nwhitehorn $ 271590Srgrimes */ 281590Srgrimes 291590Srgrimes/* 301590Srgrimes * Dynamic linker for ELF. 311590Srgrimes * 321590Srgrimes * John Polstra <jdp@polstra.com>. 331590Srgrimes */ 341590Srgrimes 351590Srgrimes#ifndef __GNUC__ 361590Srgrimes#error "GCC is needed to compile this file" 371590Srgrimes#endif 381590Srgrimes 391590Srgrimes#include <sys/param.h> 401590Srgrimes#include <sys/mount.h> 4187628Sdwmalone#include <sys/mman.h> 4287628Sdwmalone#include <sys/stat.h> 4387628Sdwmalone#include <sys/sysctl.h> 4487628Sdwmalone#include <sys/uio.h> 4587628Sdwmalone#include <sys/utsname.h> 4687628Sdwmalone#include <sys/ktrace.h> 4787233Smarkm 4887233Smarkm#include <dlfcn.h> 4987233Smarkm#include <err.h> 501590Srgrimes#include <errno.h> 511590Srgrimes#include <fcntl.h> 521590Srgrimes#include <stdarg.h> 531590Srgrimes#include <stdio.h> 541590Srgrimes#include <stdlib.h> 551590Srgrimes#include <string.h> 5687233Smarkm#include <unistd.h> 5787180Smarkm 5887180Smarkm#include "debug.h" 591590Srgrimes#include "rtld.h" 601590Srgrimes#include "libmap.h" 611590Srgrimes#include "rtld_tls.h" 6287180Smarkm 631590Srgrimes#ifndef COMPAT_32BIT 641590Srgrimes#define PATH_RTLD "/libexec/ld-elf.so.1" 651590Srgrimes#else 661590Srgrimes#define PATH_RTLD "/libexec/ld-elf32.so.1" 6740102Smarkm#endif 6841079Sjdp 691590Srgrimes/* Types. */ 701590Srgrimestypedef void (*func_ptr_type)(); 711590Srgrimestypedef void * (*path_enum_proc) (const char *path, size_t len, void *arg); 721590Srgrimes 731590Srgrimes/* 741590Srgrimes * This structure provides a reentrant way to keep a list of objects and 751590Srgrimes * check which ones have already been processed in some way. 761590Srgrimes */ 771590Srgrimestypedef struct Struct_DoneList { 781590Srgrimes const Obj_Entry **objs; /* Array of object pointers */ 7941279Sjdp unsigned int num_alloc; /* Allocated size of the array */ 8091714Sdes unsigned int num_used; /* Number of array slots used */ 813702Spst} DoneList; 8287173Smarkm 831590Srgrimes/* 841590Srgrimes * Function declarations. 8589994Sdes */ 8689994Sdesstatic const char *basename(const char *); 8789994Sdesstatic void die(void) __dead2; 8889994Sdesstatic void digest_dynamic1(Obj_Entry *, int, const Elf_Dyn **, 8989994Sdes const Elf_Dyn **); 9089994Sdesstatic void digest_dynamic2(Obj_Entry *, const Elf_Dyn *, const Elf_Dyn *); 9189994Sdesstatic void digest_dynamic(Obj_Entry *, int); 9289994Sdesstatic Obj_Entry *digest_phdr(const Elf_Phdr *, int, caddr_t, const char *); 9389994Sdesstatic Obj_Entry *dlcheck(void *); 9489994Sdesstatic Obj_Entry *do_load_object(int, const char *, char *, struct stat *, int); 9589994Sdesstatic int do_search_info(const Obj_Entry *obj, int, struct dl_serinfo *); 9689994Sdesstatic bool donelist_check(DoneList *, const Obj_Entry *); 9789994Sdesstatic void errmsg_restore(char *); 9889994Sdesstatic char *errmsg_save(void); 991590Srgrimesstatic void *fill_search_info(const char *, size_t, void *); 10087173Smarkmstatic char *find_library(const char *, const Obj_Entry *); 10187173Smarkmstatic const char *gethints(void); 10287173Smarkmstatic void init_dag(Obj_Entry *); 10376786Sobrienstatic void init_dag1(Obj_Entry *, Obj_Entry *, DoneList *); 10476786Sobrienstatic void init_rtld(caddr_t, Elf_Auxinfo **); 10589994Sdesstatic void initlist_add_neededs(Needed_Entry *, Objlist *); 10687173Smarkmstatic void initlist_add_objects(Obj_Entry *, Obj_Entry **, Objlist *); 10789994Sdesstatic void linkmap_add(Obj_Entry *); 10889994Sdesstatic void linkmap_delete(Obj_Entry *); 1091590Srgrimesstatic int load_needed_objects(Obj_Entry *, int); 1101590Srgrimesstatic int load_preload_objects(void); 1111590Srgrimesstatic Obj_Entry *load_object(const char *, const Obj_Entry *, int); 1121590Srgrimesstatic Obj_Entry *obj_from_addr(const void *); 1131590Srgrimesstatic void objlist_call_fini(Objlist *, bool, int *); 11489994Sdesstatic void objlist_call_init(Objlist *, int *); 1151590Srgrimesstatic void objlist_clear(Objlist *); 11642272Seivindstatic Objlist_Entry *objlist_find(Objlist *, const Obj_Entry *); 11789994Sdesstatic void objlist_init(Objlist *); 11842272Seivindstatic void objlist_push_head(Objlist *, Obj_Entry *); 11989994Sdesstatic void objlist_push_tail(Objlist *, Obj_Entry *); 12089994Sdesstatic void objlist_remove(Objlist *, Obj_Entry *); 1211590Srgrimesstatic void *path_enumerate(const char *, path_enum_proc, void *); 12289994Sdesstatic int relocate_objects(Obj_Entry *, bool, Obj_Entry *); 12389994Sdesstatic int rtld_dirname(const char *, char *); 12489994Sdesstatic int rtld_dirname_abs(const char *, char *); 12589994Sdesstatic void rtld_exit(void); 12689994Sdesstatic char *search_library_path(const char *, const char *); 12789994Sdesstatic const void **get_program_var_addr(const char *); 12889994Sdesstatic void set_program_var(const char *, const void *); 12989994Sdesstatic const Elf_Sym *symlook_default(const char *, unsigned long, 13089994Sdes const Obj_Entry *, const Obj_Entry **, const Ver_Entry *, int); 13189994Sdesstatic const Elf_Sym *symlook_list(const char *, unsigned long, const Objlist *, 13289994Sdes const Obj_Entry **, const Ver_Entry *, int, DoneList *); 13389994Sdesstatic const Elf_Sym *symlook_needed(const char *, unsigned long, 13489994Sdes const Needed_Entry *, const Obj_Entry **, const Ver_Entry *, 13589994Sdes int, DoneList *); 13689994Sdesstatic void trace_loaded_objects(Obj_Entry *); 13789994Sdesstatic void unlink_object(Obj_Entry *); 13889994Sdesstatic void unload_object(Obj_Entry *); 13989994Sdesstatic void unref_dag(Obj_Entry *); 14089994Sdesstatic void ref_dag(Obj_Entry *); 14189994Sdesstatic int origin_subst_one(char **, const char *, const char *, 14294203Sru const char *, char *); 14389994Sdesstatic char *origin_subst(const char *, const char *); 14494203Srustatic int rtld_verify_versions(const Objlist *); 14589994Sdesstatic int rtld_verify_object_versions(Obj_Entry *); 14689994Sdesstatic void object_add_name(Obj_Entry *, const char *); 14789994Sdesstatic int object_match_name(const Obj_Entry *, const char *); 14889994Sdesstatic void ld_utrace_log(int, void *, void *, size_t, int, const char *); 14989994Sdesstatic void rtld_fill_dl_phdr_info(const Obj_Entry *obj, 15089994Sdes struct dl_phdr_info *phdr_info); 15189994Sdes 15291714Sdesvoid r_debug_state(struct r_debug *, struct link_map *); 15389994Sdes 15489994Sdes/* 15589994Sdes * Data declarations. 15689994Sdes */ 15789994Sdesstatic char *error_message; /* Message for dlerror(), or NULL */ 1581590Srgrimesstruct r_debug r_debug; /* for GDB; */ 15989994Sdesstatic bool libmap_disable; /* Disable libmap */ 1601590Srgrimesstatic char *libmap_override; /* Maps to use in addition to libmap.conf */ 1611590Srgrimesstatic bool trust; /* False for setuid and setgid programs */ 1621590Srgrimesstatic bool dangerous_ld_env; /* True if environment variables have been 16389994Sdes used to affect the libraries loaded */ 16489994Sdesstatic char *ld_bind_now; /* Environment variable for immediate binding */ 16535559Speterstatic char *ld_debug; /* Environment variable for debugging */ 16646007Sachestatic char *ld_library_path; /* Environment variable for search path */ 16789994Sdesstatic char *ld_preload; /* Environment variable for libraries to 16845431Sbrian load first */ 16942272Seivindstatic char *ld_elf_hints_path; /* Environment variable for alternative hints path */ 17094203Srustatic char *ld_tracing; /* Called from ldd to print libs */ 17194203Srustatic char *ld_utrace; /* Use utrace() to log events. */ 17221528Sdavidnstatic Obj_Entry *obj_list; /* Head of linked list of shared objects */ 17374874Smarkmstatic Obj_Entry **obj_tail; /* Link field of last object in list */ 1741590Srgrimesstatic Obj_Entry *obj_main; /* The main program shared object */ 17542272Seivindstatic Obj_Entry obj_rtld; /* The dynamic linker shared object */ 17642272Seivindstatic unsigned int obj_count; /* Number of objects in obj_list */ 17776942Sguidostatic unsigned int obj_loads; /* Number of objects in obj_list */ 17842272Seivind 17942272Seivindstatic Objlist list_global = /* Objects dlopened with RTLD_GLOBAL */ 18089994Sdes STAILQ_HEAD_INITIALIZER(list_global); 18176788Sobrienstatic Objlist list_main = /* Objects loaded at program startup */ 18276788Sobrien STAILQ_HEAD_INITIALIZER(list_main); 18389994Sdesstatic Objlist list_fini = /* Objects needing fini() calls */ 18442272Seivind STAILQ_HEAD_INITIALIZER(list_fini); 1851590Srgrimes 1861590SrgrimesElf_Sym sym_zero; /* For resolving undefined weak refs. */ 1871590Srgrimes 1881590Srgrimes#define GDB_STATE(s,m) r_debug.r_state = s; r_debug_state(&r_debug,m); 1891590Srgrimes 1901590Srgrimesextern Elf_Dyn _DYNAMIC; 1911590Srgrimes#pragma weak _DYNAMIC 19235557Speter#ifndef RTLD_IS_DYNAMIC 19346007Sache#define RTLD_IS_DYNAMIC() (&_DYNAMIC != NULL) 19489994Sdes#endif 19524360Simp 1961590Srgrimesint osreldate, pagesize; 1971590Srgrimes 1981590Srgrimes/* 1991590Srgrimes * Global declarations normally provided by crt1. The dynamic linker is 2001590Srgrimes * not built with crt1, so we have to provide them ourselves. 20189994Sdes */ 2021590Srgrimeschar *__progname; 20389994Sdeschar **environ; 20481555Smike 20581555Smike/* 20689994Sdes * Globals to control TLS allocation. 2071590Srgrimes */ 2081590Srgrimessize_t tls_last_offset; /* Static TLS offset of last module */ 2091590Srgrimessize_t tls_last_size; /* Static TLS size of last module */ 2101590Srgrimessize_t tls_static_space; /* Static TLS space allocated */ 2111590Srgrimesint tls_dtv_generation = 1; /* Used to detect when dtv size changes */ 2121590Srgrimesint tls_max_index = 1; /* Largest module index allocated */ 2131590Srgrimes 21489994Sdes/* 2151590Srgrimes * Fill in a DoneList with an allocation large enough to hold all of 21627605Scharnier * the currently-loaded objects. Keep this as a macro since it calls 2171590Srgrimes * alloca and we want that to occur within the scope of the caller. 2181590Srgrimes */ 2191590Srgrimes#define donelist_init(dlp) \ 2201590Srgrimes ((dlp)->objs = alloca(obj_count * sizeof (dlp)->objs[0]), \ 22189994Sdes assert((dlp)->objs != NULL), \ 22289994Sdes (dlp)->num_alloc = obj_count, \ 22389994Sdes (dlp)->num_used = 0) 22489994Sdes 2251590Srgrimes#define UTRACE_DLOPEN_START 1 22689994Sdes#define UTRACE_DLOPEN_STOP 2 2271590Srgrimes#define UTRACE_DLCLOSE_START 3 22889994Sdes#define UTRACE_DLCLOSE_STOP 4 2291590Srgrimes#define UTRACE_LOAD_OBJECT 5 2301590Srgrimes#define UTRACE_UNLOAD_OBJECT 6 2311590Srgrimes#define UTRACE_ADD_RUNDEP 7 2321590Srgrimes#define UTRACE_PRELOAD_FINISHED 8 23389994Sdes#define UTRACE_INIT_CALL 9 23489994Sdes#define UTRACE_FINI_CALL 10 23589994Sdes 2361590Srgrimesstruct utrace_rtld { 2371590Srgrimes char sig[4]; /* 'RTLD' */ 2381590Srgrimes int event; 2391590Srgrimes void *handle; 2401590Srgrimes void *mapbase; /* Used for 'parent' and 'init/fini' */ 24123985Sdavidn size_t mapsize; 2421590Srgrimes int refcnt; /* Used for 'mode' */ 2431590Srgrimes char name[MAXPATHLEN]; 2441590Srgrimes}; 2451590Srgrimes 24623985Sdavidn#define LD_UTRACE(e, h, mb, ms, r, n) do { \ 24723985Sdavidn if (ld_utrace != NULL) \ 24823985Sdavidn ld_utrace_log(e, h, mb, ms, r, n); \ 24923985Sdavidn} while (0) 25089994Sdes 25189994Sdesstatic void 25276786Sobrienld_utrace_log(int event, void *handle, void *mapbase, size_t mapsize, 25387173Smarkm int refcnt, const char *name) 25489994Sdes{ 25589994Sdes struct utrace_rtld ut; 25689994Sdes 25789994Sdes ut.sig[0] = 'R'; 25823985Sdavidn ut.sig[1] = 'T'; 25923985Sdavidn ut.sig[2] = 'L'; 26021528Sdavidn ut.sig[3] = 'D'; 26189994Sdes ut.event = event; 26289994Sdes ut.handle = handle; 26389994Sdes ut.mapbase = mapbase; 2641590Srgrimes ut.mapsize = mapsize; 2651590Srgrimes ut.refcnt = refcnt; 2661590Srgrimes bzero(ut.name, sizeof(ut.name)); 26789994Sdes if (name) 26889994Sdes strlcpy(ut.name, name, sizeof(ut.name)); 26989994Sdes utrace(&ut, sizeof(ut)); 27089994Sdes} 2711590Srgrimes 2721590Srgrimes/* 27321528Sdavidn * Main entry point for dynamic linking. The first argument is the 2741590Srgrimes * stack pointer. The stack is expected to be laid out as described 2751590Srgrimes * in the SVR4 ABI specification, Intel 386 Processor Supplement. 2761590Srgrimes * Specifically, the stack pointer points to a word containing 2771590Srgrimes * ARGC. Following that in the stack is a null-terminated sequence 2781590Srgrimes * of pointers to argument strings. Then comes a null-terminated 27989994Sdes * sequence of pointers to environment strings. Finally, there is a 2801590Srgrimes * sequence of "auxiliary vector" entries. 28189994Sdes * 2821590Srgrimes * The second argument points to a place to store the dynamic linker's 2831590Srgrimes * exit procedure pointer and the third to a place to store the main 28423985Sdavidn * program's object. 28589994Sdes * 2861590Srgrimes * The return value is the main program's entry point. 28789994Sdes */ 28889994Sdesfunc_ptr_type 28989994Sdes_rtld(Elf_Addr *sp, func_ptr_type *exit_proc, Obj_Entry **objp) 29089994Sdes{ 2913205Spst Elf_Auxinfo *aux_info[AT_COUNT]; 29289994Sdes int i; 29389994Sdes int argc; 29489994Sdes char **argv; 29589994Sdes char **env; 29689994Sdes Elf_Auxinfo *aux; 29789994Sdes Elf_Auxinfo *auxp; 29889994Sdes const char *argv0; 29989994Sdes Objlist_Entry *entry; 30089994Sdes Obj_Entry *obj; 30189994Sdes Obj_Entry **preload_tail; 30297376Sdes Objlist initlist; 30389994Sdes int lockstate; 30441279Sjdp 30541279Sjdp /* 3061590Srgrimes * On entry, the dynamic linker itself has not been relocated yet. 3071590Srgrimes * Be very careful not to reference any global data until after 30889994Sdes * init_rtld has returned. It is OK to reference file-scope statics 30989994Sdes * and string constants, and to call static and global functions. 31089994Sdes */ 3111590Srgrimes 31289994Sdes /* Find the auxiliary vector on the stack. */ 31389994Sdes argc = *sp++; 31489994Sdes argv = (char **) sp; 31589994Sdes sp += argc + 1; /* Skip over arguments and NULL terminator */ 31689994Sdes env = (char **) sp; 31789994Sdes while (*sp++ != 0) /* Skip over environment, and NULL terminator */ 31889994Sdes ; 31989994Sdes aux = (Elf_Auxinfo *) sp; 32089994Sdes 3211590Srgrimes /* Digest the auxiliary vector. */ 3221590Srgrimes for (i = 0; i < AT_COUNT; i++) 32389994Sdes aux_info[i] = NULL; 32489994Sdes for (auxp = aux; auxp->a_type != AT_NULL; auxp++) { 32589994Sdes if (auxp->a_type < AT_COUNT) 32689994Sdes aux_info[auxp->a_type] = auxp; 32797376Sdes } 3281590Srgrimes 3291590Srgrimes /* Initialize and relocate ourselves. */ 33023985Sdavidn assert(aux_info[AT_BASE] != NULL); 33123985Sdavidn init_rtld((caddr_t) aux_info[AT_BASE]->a_un.a_ptr, aux_info); 33289994Sdes 33389994Sdes __progname = obj_rtld.path; 33423985Sdavidn argv0 = argv[0] != NULL ? argv[0] : "(null)"; 33523985Sdavidn environ = env; 33623985Sdavidn 3371590Srgrimes trust = !issetugid(); 33889994Sdes 3391590Srgrimes ld_bind_now = getenv(LD_ "BIND_NOW"); 34038374Sjkoshy /* 3411590Srgrimes * If the process is tainted, then we un-set the dangerous environment 3421590Srgrimes * variables. The process will be marked as tainted until setuid(2) 3431590Srgrimes * is called. If any child process calls setuid(2) we do not want any 3441590Srgrimes * future processes to honor the potentially un-safe variables. 3451590Srgrimes */ 34676942Sguido if (!trust) { 3471590Srgrimes if (unsetenv(LD_ "PRELOAD") || unsetenv(LD_ "LIBMAP") || 3481590Srgrimes unsetenv(LD_ "LIBRARY_PATH") || unsetenv(LD_ "LIBMAP_DISABLE") || 3491590Srgrimes unsetenv(LD_ "DEBUG") || unsetenv(LD_ "ELF_HINTS_PATH")) { 35041279Sjdp _rtld_error("environment corrupt; aborting"); 35141279Sjdp die(); 35241279Sjdp } 35341279Sjdp } 35441279Sjdp ld_debug = getenv(LD_ "DEBUG"); 35521528Sdavidn libmap_disable = getenv(LD_ "LIBMAP_DISABLE") != NULL; 35695243Sdes libmap_override = getenv(LD_ "LIBMAP"); 35795243Sdes ld_library_path = getenv(LD_ "LIBRARY_PATH"); 35897376Sdes ld_preload = getenv(LD_ "PRELOAD"); 35983519Srwatson ld_elf_hints_path = getenv(LD_ "ELF_HINTS_PATH"); 36083519Srwatson dangerous_ld_env = libmap_disable || (libmap_override != NULL) || 36183519Srwatson (ld_library_path != NULL) || (ld_preload != NULL) || 36283519Srwatson (ld_elf_hints_path != NULL); 36383519Srwatson ld_tracing = getenv(LD_ "TRACE_LOADED_OBJECTS"); 36483519Srwatson ld_utrace = getenv(LD_ "UTRACE"); 36583519Srwatson 36646007Sache if ((ld_elf_hints_path == NULL) || strlen(ld_elf_hints_path) == 0) 36735557Speter ld_elf_hints_path = _PATH_ELF_HINTS; 36821528Sdavidn 36926021Spst if (ld_debug != NULL && *ld_debug != '\0') 37023985Sdavidn debug = 1; 37197376Sdes dbg("%s is initialized, base address = %p", __progname, 37223985Sdavidn (caddr_t) aux_info[AT_BASE]->a_un.a_ptr); 37323985Sdavidn dbg("RTLD dynamic = %p", obj_rtld.dynamic); 37423985Sdavidn dbg("RTLD pltgot = %p", obj_rtld.pltgot); 37587173Smarkm 37687173Smarkm /* 37787173Smarkm * Load the main program, or process its program header if it is 37889994Sdes * already loaded. 37987173Smarkm */ 3801590Srgrimes if (aux_info[AT_EXECFD] != NULL) { /* Load the main program. */ 38135557Speter int fd = aux_info[AT_EXECFD]->a_un.a_val; 38246007Sache dbg("loading main program"); 38321528Sdavidn obj_main = map_object(fd, argv0, NULL); 38421528Sdavidn close(fd); 38597376Sdes if (obj_main == NULL) 38697376Sdes die(); 38723985Sdavidn } else { /* Main program already loaded. */ 38887173Smarkm const Elf_Phdr *phdr; 38987173Smarkm int phnum; 39087173Smarkm caddr_t entry; 39189994Sdes 39287173Smarkm dbg("processing main program's program header"); 39323985Sdavidn assert(aux_info[AT_PHDR] != NULL); 39423985Sdavidn phdr = (const Elf_Phdr *) aux_info[AT_PHDR]->a_un.a_ptr; 39523985Sdavidn assert(aux_info[AT_PHNUM] != NULL); 39681555Smike phnum = aux_info[AT_PHNUM]->a_un.a_val; 39789994Sdes assert(aux_info[AT_PHENT] != NULL); 39823985Sdavidn assert(aux_info[AT_PHENT]->a_un.a_val == sizeof(Elf_Phdr)); 39921528Sdavidn assert(aux_info[AT_ENTRY] != NULL); 4002224Sguido entry = (caddr_t) aux_info[AT_ENTRY]->a_un.a_ptr; 4012224Sguido if ((obj_main = digest_phdr(phdr, phnum, entry, argv0)) == NULL) 4022224Sguido die(); 4032224Sguido } 4042224Sguido 4052224Sguido if (aux_info[AT_EXECPATH] != 0) { 4062224Sguido char *kexecpath; 40750124Simp char buf[MAXPATHLEN]; 40850124Simp 40950124Simp kexecpath = aux_info[AT_EXECPATH]->a_un.a_ptr; 41050124Simp dbg("AT_EXECPATH %p %s", kexecpath, kexecpath); 41150124Simp if (kexecpath[0] == '/') 41250124Simp obj_main->path = kexecpath; 41389994Sdes else if (getcwd(buf, sizeof(buf)) == NULL || 41489994Sdes strlcat(buf, "/", sizeof(buf)) >= sizeof(buf) || 41589994Sdes strlcat(buf, kexecpath, sizeof(buf)) >= sizeof(buf)) 41650124Simp obj_main->path = xstrdup(argv0); 41750124Simp else 4181590Srgrimes obj_main->path = xstrdup(buf); 41923985Sdavidn } else { 42023985Sdavidn dbg("No AT_EXECPATH"); 42123985Sdavidn obj_main->path = xstrdup(argv0); 42223985Sdavidn } 42323985Sdavidn dbg("obj_main path %s", obj_main->path); 42489994Sdes obj_main->mainprog = true; 4251590Srgrimes 4261590Srgrimes /* 4273205Spst * Get the actual dynamic linker pathname from the executable if 4283205Spst * possible. (It should always be possible.) That ensures that 42989994Sdes * gdb will find the right dynamic linker even if a non-standard 43089994Sdes * one is being used. 4313205Spst */ 43289994Sdes if (obj_main->interp != NULL && 43323985Sdavidn strcmp(obj_main->interp, obj_rtld.path) != 0) { 43489994Sdes free(obj_rtld.path); 43523985Sdavidn obj_rtld.path = xstrdup(obj_main->interp); 43623985Sdavidn __progname = obj_rtld.path; 43723985Sdavidn } 43821528Sdavidn 43921528Sdavidn digest_dynamic(obj_main, 0); 44023985Sdavidn 44189994Sdes linkmap_add(obj_main); 44289994Sdes linkmap_add(&obj_rtld); 44323985Sdavidn 44489994Sdes /* Link the main program into the list of objects. */ 44589994Sdes *obj_tail = obj_main; 44623985Sdavidn obj_tail = &obj_main->next; 44789994Sdes obj_count++; 44823985Sdavidn obj_loads++; 44923985Sdavidn /* Make sure we don't call the main program's init and fini functions. */ 45076788Sobrien obj_main->init = obj_main->fini = (Elf_Addr)NULL; 45123985Sdavidn 45223985Sdavidn /* Initialize a fake symbol for resolving undefined weak references. */ 45323985Sdavidn sym_zero.st_info = ELF_ST_INFO(STB_GLOBAL, STT_NOTYPE); 45489994Sdes sym_zero.st_shndx = SHN_UNDEF; 45589994Sdes sym_zero.st_value = -(uintptr_t)obj_main->relocbase; 45623985Sdavidn 45789994Sdes if (!libmap_disable) 45821528Sdavidn libmap_disable = (bool)lm_init(libmap_override); 45921528Sdavidn 46089994Sdes dbg("loading LD_PRELOAD libraries"); 46189994Sdes if (load_preload_objects() == -1) 46221528Sdavidn die(); 46323985Sdavidn preload_tail = obj_tail; 46474874Smarkm 46574874Smarkm dbg("loading needed objects"); 46674874Smarkm if (load_needed_objects(obj_main, 0) == -1) 46797376Sdes die(); 46889994Sdes 46974874Smarkm /* Make a list of all objects loaded at startup. */ 47074874Smarkm for (obj = obj_list; obj != NULL; obj = obj->next) { 47189994Sdes objlist_push_tail(&list_main, obj); 47289994Sdes obj->refcount++; 47389994Sdes } 47489994Sdes 47589994Sdes dbg("checking for required versions"); 47689994Sdes if (rtld_verify_versions(&list_main) == -1 && !ld_tracing) 47797376Sdes die(); 47889994Sdes 47989994Sdes if (ld_tracing) { /* We're done */ 48089994Sdes trace_loaded_objects(obj_main); 48189994Sdes exit(0); 48289994Sdes } 48389994Sdes 48474874Smarkm if (getenv(LD_ "DUMP_REL_PRE") != NULL) { 48589994Sdes dump_relocations(obj_main); 48689994Sdes exit (0); 48789994Sdes } 48889994Sdes 48989994Sdes /* setup TLS for main thread */ 49089994Sdes dbg("initializing initial thread local storage"); 49189994Sdes STAILQ_FOREACH(entry, &list_main, link) { 49289994Sdes /* 49374874Smarkm * Allocate all the initial objects out of the static TLS 49489994Sdes * block even if they didn't ask for it. 49589994Sdes */ 49674874Smarkm allocate_tls_offset(entry->obj); 49789994Sdes } 49889994Sdes allocate_initial_tls(obj_list); 49974874Smarkm 50074874Smarkm if (relocate_objects(obj_main, 50174874Smarkm ld_bind_now != NULL && *ld_bind_now != '\0', &obj_rtld) == -1) 50289994Sdes die(); 50321528Sdavidn 50497376Sdes dbg("doing copy relocations"); 50589994Sdes if (do_copy_relocations(obj_main) == -1) 50689994Sdes die(); 50789994Sdes 50889994Sdes if (getenv(LD_ "DUMP_REL_POST") != NULL) { 50989994Sdes dump_relocations(obj_main); 51089994Sdes exit (0); 51189994Sdes } 51289994Sdes 51391714Sdes dbg("initializing key program variables"); 51489994Sdes set_program_var("__progname", argv[0] != NULL ? basename(argv[0]) : ""); 51589994Sdes set_program_var("environ", env); 51689994Sdes set_program_var("__elf_aux_vector", aux); 51789994Sdes 51889994Sdes dbg("initializing thread locks"); 51989994Sdes lockdflt_init(); 52041279Sjdp 52197376Sdes /* Make a list of init functions to call. */ 52289994Sdes objlist_init(&initlist); 52341279Sjdp initlist_add_objects(obj_list, preload_tail, &initlist); 52441279Sjdp 52574874Smarkm r_debug_state(NULL, &obj_main->linkmap); /* say hello to gdb! */ 52697376Sdes 52721528Sdavidn lockstate = wlock_acquire(rtld_bind_lock); 5283205Spst objlist_call_init(&initlist, &lockstate); 52921528Sdavidn objlist_clear(&initlist); 53023148Sache wlock_release(rtld_bind_lock, lockstate); 53121528Sdavidn 53289994Sdes dbg("transferring control to program entry point = %p", obj_main->entry); 53341279Sjdp 53441279Sjdp /* Return the exit procedure and the program entry point. */ 53521528Sdavidn *exit_proc = rtld_exit; 53621528Sdavidn *objp = obj_main; 5371590Srgrimes return (func_ptr_type) obj_main->entry; 53894203Sru} 53923985Sdavidn 54023985SdavidnElf_Addr 54189994Sdes_rtld_bind(Obj_Entry *obj, Elf_Size reloff) 54289994Sdes{ 54323985Sdavidn const Elf_Rel *rel; 54423985Sdavidn const Elf_Sym *def; 54523985Sdavidn const Obj_Entry *defobj; 54621528Sdavidn Elf_Addr *where; 54789994Sdes Elf_Addr target; 54889994Sdes int lockstate; 54989994Sdes 55089994Sdes lockstate = rlock_acquire(rtld_bind_lock); 55123985Sdavidn if (obj->pltrel) 55286450Srwatson rel = (const Elf_Rel *) ((caddr_t) obj->pltrel + reloff); 55386450Srwatson else 55486450Srwatson rel = (const Elf_Rel *) ((caddr_t) obj->pltrela + reloff); 55589994Sdes 55694203Sru where = (Elf_Addr *) (obj->relocbase + rel->r_offset); 55786450Srwatson def = find_symdef(ELF_R_SYM(rel->r_info), obj, &defobj, true, NULL); 55889994Sdes if (def == NULL) 55989994Sdes die(); 56086450Srwatson 56186450Srwatson target = (Elf_Addr)(defobj->relocbase + def->st_value); 56289994Sdes 56394203Sru dbg("\"%s\" in \"%s\" ==> %p in \"%s\"", 56486450Srwatson defobj->strtab + def->st_name, basename(obj->path), 5651590Srgrimes (void *)target, basename(defobj->path)); 5661590Srgrimes 56721528Sdavidn /* 5683205Spst * Write the new contents for the jmpslot. Note that depending on 5691590Srgrimes * architecture, the value which we need to return back to the 5701590Srgrimes * lazy binding trampoline may or may not be the target 5711590Srgrimes * address. The value returned from reloc_jmpslot() is the value 5721590Srgrimes * that the trampoline needs. 5731590Srgrimes */ 57423985Sdavidn target = reloc_jmpslot(where, target, defobj, obj, rel); 57523985Sdavidn rlock_release(rtld_bind_lock, lockstate); 57623985Sdavidn return target; 57789994Sdes} 57889994Sdes 57981555Smike/* 58081555Smike * Error reporting function. Use it like printf. If formats the message 58181555Smike * into a buffer, and sets things up so that the next call to dlerror() 58289994Sdes * will return the message. 58389994Sdes */ 58481555Smikevoid 58523985Sdavidn_rtld_error(const char *fmt, ...) 58689994Sdes{ 58721528Sdavidn static char buf[512]; 58897376Sdes va_list ap; 58989994Sdes 59089994Sdes va_start(ap, fmt); 59189994Sdes vsnprintf(buf, sizeof buf, fmt, ap); 5921590Srgrimes error_message = buf; 5931590Srgrimes va_end(ap); 59441279Sjdp} 59541279Sjdp 59641279Sjdp/* 59741279Sjdp * Return a dynamically-allocated copy of the current error message, if any. 59841279Sjdp */ 59941279Sjdpstatic char * 60041279Sjdperrmsg_save(void) 60141279Sjdp{ 60289994Sdes return error_message == NULL ? NULL : xstrdup(error_message); 60341279Sjdp} 60441279Sjdp 60541279Sjdp/* 60641279Sjdp * Restore the current error message from a copy which was previously saved 60741279Sjdp * by errmsg_save(). The copy is freed. 60889994Sdes */ 60989994Sdesstatic void 61041279Sjdperrmsg_restore(char *saved_msg) 61141279Sjdp{ 61241279Sjdp if (saved_msg == NULL) 61341279Sjdp error_message = NULL; 61441279Sjdp else { 61541279Sjdp _rtld_error("%s", saved_msg); 61641279Sjdp free(saved_msg); 61741279Sjdp } 61841279Sjdp} 61941279Sjdp 62041279Sjdpstatic const char * 62141279Sjdpbasename(const char *name) 62241279Sjdp{ 62341279Sjdp const char *p = strrchr(name, '/'); 62441279Sjdp return p != NULL ? p + 1 : name; 62541279Sjdp} 62641279Sjdp 62741279Sjdpstatic struct utsname uts; 62841279Sjdp 62989994Sdesstatic int 63089994Sdesorigin_subst_one(char **res, const char *real, const char *kw, const char *subst, 63189994Sdes char *may_free) 63241279Sjdp{ 63341279Sjdp const char *p, *p1; 63489994Sdes char *res1; 63589994Sdes int subst_len; 63689994Sdes int kw_len; 63741279Sjdp 63841279Sjdp res1 = *res = NULL; 63941279Sjdp p = real; 64041279Sjdp subst_len = kw_len = 0; 64141279Sjdp for (;;) { 64241279Sjdp p1 = strstr(p, kw); 64341279Sjdp if (p1 != NULL) { 64441279Sjdp if (subst_len == 0) { 64541279Sjdp subst_len = strlen(subst); 64641279Sjdp kw_len = strlen(kw); 64789994Sdes } 64841279Sjdp if (*res == NULL) { 64941279Sjdp *res = xmalloc(PATH_MAX); 65041279Sjdp res1 = *res; 65174874Smarkm } 65274874Smarkm if ((res1 - *res) + subst_len + (p1 - p) >= PATH_MAX) { 65389994Sdes _rtld_error("Substitution of %s in %s cannot be performed", 65489994Sdes kw, real); 65589994Sdes if (may_free != NULL) 65689994Sdes free(may_free); 65789994Sdes free(res); 65889994Sdes return (false); 65989994Sdes } 66089994Sdes memcpy(res1, p, p1 - p); 66189994Sdes res1 += p1 - p; 66274874Smarkm memcpy(res1, subst, subst_len); 66374874Smarkm res1 += subst_len; 66489994Sdes p = p1 + kw_len; 66589994Sdes } else { 66689994Sdes if (*res == NULL) { 66774874Smarkm if (may_free != NULL) 66889994Sdes *res = may_free; 66974874Smarkm else 67041279Sjdp *res = xstrdup(real); 67174874Smarkm return (true); 67274874Smarkm } 67389994Sdes *res1 = '\0'; 67474874Smarkm if (may_free != NULL) 67574874Smarkm free(may_free); 67689994Sdes if (strlcat(res1, p, PATH_MAX - (res1 - *res)) >= PATH_MAX) { 67741279Sjdp free(res); 67872215Snectar return (false); 67989994Sdes } 68089994Sdes return (true); 68189994Sdes } 68289994Sdes } 68387177Smarkm} 68472215Snectar 68589994Sdesstatic char * 68689994Sdesorigin_subst(const char *real, const char *origin_path) 68772215Snectar{ 68889994Sdes char *res1, *res2, *res3, *res4; 68989994Sdes 69089994Sdes if (uts.sysname[0] == '\0') { 69189994Sdes if (uname(&uts) != 0) { 69289994Sdes _rtld_error("utsname failed: %d", errno); 69389994Sdes return (NULL); 69472215Snectar } 69572215Snectar } 69672215Snectar if (!origin_subst_one(&res1, real, "$ORIGIN", origin_path, NULL) || 69772215Snectar !origin_subst_one(&res2, res1, "$OSNAME", uts.sysname, res1) || 69889994Sdes !origin_subst_one(&res3, res2, "$OSREL", uts.release, res2) || 69972215Snectar !origin_subst_one(&res4, res3, "$PLATFORM", uts.machine, res3)) 70072215Snectar return (NULL); 70172215Snectar return (res4); 70272215Snectar} 70389994Sdes 70472215Snectarstatic void 70572215Snectardie(void) 70689994Sdes{ 70772215Snectar const char *msg = dlerror(); 70872215Snectar 70972215Snectar if (msg == NULL) 71072215Snectar msg = "Fatal error"; 71172215Snectar errx(1, "%s", msg); 71272215Snectar} 71372215Snectar 71472215Snectar/* 71572215Snectar * Process a shared object's DYNAMIC section, and save the important 71689994Sdes * information in its Obj_Entry structure. 71772215Snectar */ 71889994Sdesstatic void 71972215Snectardigest_dynamic1(Obj_Entry *obj, int early, const Elf_Dyn **dyn_rpath, 72072215Snectar const Elf_Dyn **dyn_soname) 72172215Snectar{ 72289994Sdes const Elf_Dyn *dynp; 72372215Snectar Needed_Entry **needed_tail = &obj->needed; 72489994Sdes int plttype = DT_REL; 72589994Sdes 72672215Snectar *dyn_rpath = NULL; 72741279Sjdp *dyn_soname = NULL; 72827605Scharnier 72987177Smarkm obj->bind_now = false; 73027605Scharnier for (dynp = obj->dynamic; dynp->d_tag != DT_NULL; dynp++) { 73176791Sobrien switch (dynp->d_tag) { 73227605Scharnier 73327605Scharnier case DT_REL: 73427605Scharnier obj->rel = (const Elf_Rel *) (obj->relocbase + dynp->d_un.d_ptr); 7351590Srgrimes break; 73623985Sdavidn 73789994Sdes case DT_RELSZ: 73874874Smarkm obj->relsize = dynp->d_un.d_val; 73989994Sdes break; 74087177Smarkm 7411590Srgrimes case DT_RELENT: 74289994Sdes assert(dynp->d_un.d_val == sizeof(Elf_Rel)); 7431590Srgrimes break; 7441590Srgrimes 74589994Sdes case DT_JMPREL: 74689994Sdes obj->pltrel = (const Elf_Rel *) 74789994Sdes (obj->relocbase + dynp->d_un.d_ptr); 74889994Sdes break; 74981555Smike 7501590Srgrimes case DT_PLTRELSZ: 7511590Srgrimes obj->pltrelsize = dynp->d_un.d_val; 7521590Srgrimes break; 75389994Sdes 7541590Srgrimes case DT_RELA: 75589994Sdes obj->rela = (const Elf_Rela *) (obj->relocbase + dynp->d_un.d_ptr); 7561590Srgrimes break; 7571590Srgrimes 75889994Sdes case DT_RELASZ: 75997376Sdes obj->relasize = dynp->d_un.d_val; 76089994Sdes break; 76189994Sdes 76289994Sdes case DT_RELAENT: 76389994Sdes assert(dynp->d_un.d_val == sizeof(Elf_Rela)); 76489994Sdes break; 76589994Sdes 7661590Srgrimes case DT_PLTREL: 76789994Sdes plttype = dynp->d_un.d_val; 7681590Srgrimes assert(dynp->d_un.d_val == DT_REL || plttype == DT_RELA); 7691590Srgrimes break; 77089994Sdes 77189994Sdes case DT_SYMTAB: 77289994Sdes obj->symtab = (const Elf_Sym *) 77389994Sdes (obj->relocbase + dynp->d_un.d_ptr); 77489994Sdes break; 77589994Sdes 7761590Srgrimes case DT_SYMENT: 77721528Sdavidn assert(dynp->d_un.d_val == sizeof(Elf_Sym)); 77821528Sdavidn break; 77921528Sdavidn 78089994Sdes case DT_STRTAB: 78189994Sdes obj->strtab = (const char *) (obj->relocbase + dynp->d_un.d_ptr); 78289994Sdes break; 78389994Sdes 78489994Sdes case DT_STRSZ: 78521528Sdavidn obj->strsize = dynp->d_un.d_val; 7861590Srgrimes break; 78789994Sdes 78889994Sdes case DT_VERNEED: 7891590Srgrimes obj->verneed = (const Elf_Verneed *) (obj->relocbase + 79089994Sdes dynp->d_un.d_val); 79189994Sdes break; 79221528Sdavidn 7931590Srgrimes case DT_VERNEEDNUM: 79489994Sdes obj->verneednum = dynp->d_un.d_val; 79589994Sdes break; 79689994Sdes 79789994Sdes case DT_VERDEF: 79889994Sdes obj->verdef = (const Elf_Verdef *) (obj->relocbase + 79989994Sdes dynp->d_un.d_val); 80089994Sdes break; 80189994Sdes 80289994Sdes case DT_VERDEFNUM: 8031590Srgrimes obj->verdefnum = dynp->d_un.d_val; 8041590Srgrimes break; 80589994Sdes 80689994Sdes case DT_VERSYM: 80789994Sdes obj->versyms = (const Elf_Versym *)(obj->relocbase + 80889994Sdes dynp->d_un.d_val); 80989994Sdes break; 81089994Sdes 81189994Sdes case DT_HASH: 81289994Sdes { 81389994Sdes const Elf_Hashelt *hashtab = (const Elf_Hashelt *) 81489994Sdes (obj->relocbase + dynp->d_un.d_ptr); 8151590Srgrimes obj->nbuckets = hashtab[0]; 81676788Sobrien obj->nchains = hashtab[1]; 81742272Seivind obj->buckets = hashtab + 2; 8181590Srgrimes obj->chains = obj->buckets + obj->nbuckets; 8191590Srgrimes } 8201590Srgrimes break; 82189994Sdes 8221590Srgrimes case DT_NEEDED: 8231590Srgrimes if (!obj->rtld) { 8241590Srgrimes Needed_Entry *nep = NEW(Needed_Entry); 8251590Srgrimes nep->name = dynp->d_un.d_val; 82689994Sdes nep->obj = NULL; 8271590Srgrimes nep->next = NULL; 82889994Sdes 8291590Srgrimes *needed_tail = nep; 8301590Srgrimes needed_tail = &nep->next; 83189994Sdes } 8321590Srgrimes break; 8331590Srgrimes 8341590Srgrimes case DT_PLTGOT: 8351590Srgrimes obj->pltgot = (Elf_Addr *) (obj->relocbase + dynp->d_un.d_ptr); 8361590Srgrimes break; 8371590Srgrimes 8381590Srgrimes case DT_TEXTREL: 83942272Seivind obj->textrel = true; 8401590Srgrimes break; 8411590Srgrimes 84287173Smarkm case DT_SYMBOLIC: 84389994Sdes obj->symbolic = true; 8441590Srgrimes break; 8451590Srgrimes 84623985Sdavidn case DT_RPATH: 84781555Smike case DT_RUNPATH: /* XXX: process separately */ 84881555Smike /* 84981555Smike * We have to wait until later to process this, because we 85081555Smike * might not have gotten the address of the string table yet. 85181555Smike */ 85289994Sdes *dyn_rpath = dynp; 8531590Srgrimes break; 8541590Srgrimes 8551590Srgrimes case DT_SONAME: 85689994Sdes *dyn_soname = dynp; 85723985Sdavidn break; 85823985Sdavidn 85923985Sdavidn case DT_INIT: 86023985Sdavidn obj->init = (Elf_Addr) (obj->relocbase + dynp->d_un.d_ptr); 86189994Sdes break; 86223985Sdavidn 86389994Sdes case DT_FINI: 86423985Sdavidn obj->fini = (Elf_Addr) (obj->relocbase + dynp->d_un.d_ptr); 86523985Sdavidn break; 86676788Sobrien 86723985Sdavidn /* 86889994Sdes * Don't process DT_DEBUG on MIPS as the dynamic section 86923985Sdavidn * is mapped read-only. DT_MIPS_RLD_MAP is used instead. 87023985Sdavidn */ 87189994Sdes 87289994Sdes#ifndef __mips__ 87389994Sdes case DT_DEBUG: 87423985Sdavidn /* XXX - not implemented yet */ 87589994Sdes if (!early) 8761590Srgrimes dbg("Filling in DT_DEBUG entry"); 87789994Sdes ((Elf_Dyn*)dynp)->d_un.d_ptr = (Elf_Addr) &r_debug; 87889994Sdes break; 87923985Sdavidn#endif 88089994Sdes 88189994Sdes case DT_FLAGS: 88289994Sdes if ((dynp->d_un.d_val & DF_ORIGIN) && trust) 88389994Sdes obj->z_origin = true; 88489994Sdes if (dynp->d_un.d_val & DF_SYMBOLIC) 88589994Sdes obj->symbolic = true; 88689994Sdes if (dynp->d_un.d_val & DF_TEXTREL) 88789994Sdes obj->textrel = true; 88889994Sdes if (dynp->d_un.d_val & DF_BIND_NOW) 88989994Sdes obj->bind_now = true; 89089994Sdes if (dynp->d_un.d_val & DF_STATIC_TLS) 89189994Sdes ; 89289994Sdes break; 89389994Sdes#ifdef __mips__ 89489994Sdes case DT_MIPS_LOCAL_GOTNO: 89589994Sdes obj->local_gotno = dynp->d_un.d_val; 89689994Sdes break; 89789994Sdes 89889994Sdes case DT_MIPS_SYMTABNO: 89989994Sdes obj->symtabno = dynp->d_un.d_val; 90089994Sdes break; 90189994Sdes 90289994Sdes case DT_MIPS_GOTSYM: 90389994Sdes obj->gotsym = dynp->d_un.d_val; 90489994Sdes break; 90589994Sdes 90689994Sdes case DT_MIPS_RLD_MAP: 90789994Sdes#ifdef notyet 90889994Sdes if (!early) 90989994Sdes dbg("Filling in DT_DEBUG entry"); 91089994Sdes ((Elf_Dyn*)dynp)->d_un.d_ptr = (Elf_Addr) &r_debug; 91189994Sdes#endif 91289994Sdes break; 91389994Sdes#endif 9141590Srgrimes 9151590Srgrimes case DT_FLAGS_1: 916 if (dynp->d_un.d_val & DF_1_NOOPEN) 917 obj->z_noopen = true; 918 if ((dynp->d_un.d_val & DF_1_ORIGIN) && trust) 919 obj->z_origin = true; 920 if (dynp->d_un.d_val & DF_1_GLOBAL) 921 /* XXX */; 922 if (dynp->d_un.d_val & DF_1_BIND_NOW) 923 obj->bind_now = true; 924 if (dynp->d_un.d_val & DF_1_NODELETE) 925 obj->z_nodelete = true; 926 break; 927 928 default: 929 if (!early) { 930 dbg("Ignoring d_tag %ld = %#lx", (long)dynp->d_tag, 931 (long)dynp->d_tag); 932 } 933 break; 934 } 935 } 936 937 obj->traced = false; 938 939 if (plttype == DT_RELA) { 940 obj->pltrela = (const Elf_Rela *) obj->pltrel; 941 obj->pltrel = NULL; 942 obj->pltrelasize = obj->pltrelsize; 943 obj->pltrelsize = 0; 944 } 945} 946 947static void 948digest_dynamic2(Obj_Entry *obj, const Elf_Dyn *dyn_rpath, 949 const Elf_Dyn *dyn_soname) 950{ 951 952 if (obj->z_origin && obj->origin_path == NULL) { 953 obj->origin_path = xmalloc(PATH_MAX); 954 if (rtld_dirname_abs(obj->path, obj->origin_path) == -1) 955 die(); 956 } 957 958 if (dyn_rpath != NULL) { 959 obj->rpath = (char *)obj->strtab + dyn_rpath->d_un.d_val; 960 if (obj->z_origin) 961 obj->rpath = origin_subst(obj->rpath, obj->origin_path); 962 } 963 964 if (dyn_soname != NULL) 965 object_add_name(obj, obj->strtab + dyn_soname->d_un.d_val); 966} 967 968static void 969digest_dynamic(Obj_Entry *obj, int early) 970{ 971 const Elf_Dyn *dyn_rpath; 972 const Elf_Dyn *dyn_soname; 973 974 digest_dynamic1(obj, early, &dyn_rpath, &dyn_soname); 975 digest_dynamic2(obj, dyn_rpath, dyn_soname); 976} 977 978/* 979 * Process a shared object's program header. This is used only for the 980 * main program, when the kernel has already loaded the main program 981 * into memory before calling the dynamic linker. It creates and 982 * returns an Obj_Entry structure. 983 */ 984static Obj_Entry * 985digest_phdr(const Elf_Phdr *phdr, int phnum, caddr_t entry, const char *path) 986{ 987 Obj_Entry *obj; 988 const Elf_Phdr *phlimit = phdr + phnum; 989 const Elf_Phdr *ph; 990 int nsegs = 0; 991 992 obj = obj_new(); 993 for (ph = phdr; ph < phlimit; ph++) { 994 if (ph->p_type != PT_PHDR) 995 continue; 996 997 obj->phdr = phdr; 998 obj->phsize = ph->p_memsz; 999 obj->relocbase = (caddr_t)phdr - ph->p_vaddr; 1000 break; 1001 } 1002 1003 for (ph = phdr; ph < phlimit; ph++) { 1004 switch (ph->p_type) { 1005 1006 case PT_INTERP: 1007 obj->interp = (const char *)(ph->p_vaddr + obj->relocbase); 1008 break; 1009 1010 case PT_LOAD: 1011 if (nsegs == 0) { /* First load segment */ 1012 obj->vaddrbase = trunc_page(ph->p_vaddr); 1013 obj->mapbase = obj->vaddrbase + obj->relocbase; 1014 obj->textsize = round_page(ph->p_vaddr + ph->p_memsz) - 1015 obj->vaddrbase; 1016 } else { /* Last load segment */ 1017 obj->mapsize = round_page(ph->p_vaddr + ph->p_memsz) - 1018 obj->vaddrbase; 1019 } 1020 nsegs++; 1021 break; 1022 1023 case PT_DYNAMIC: 1024 obj->dynamic = (const Elf_Dyn *)(ph->p_vaddr + obj->relocbase); 1025 break; 1026 1027 case PT_TLS: 1028 obj->tlsindex = 1; 1029 obj->tlssize = ph->p_memsz; 1030 obj->tlsalign = ph->p_align; 1031 obj->tlsinitsize = ph->p_filesz; 1032 obj->tlsinit = (void*)(ph->p_vaddr + obj->relocbase); 1033 break; 1034 } 1035 } 1036 if (nsegs < 1) { 1037 _rtld_error("%s: too few PT_LOAD segments", path); 1038 return NULL; 1039 } 1040 1041 obj->entry = entry; 1042 return obj; 1043} 1044 1045static Obj_Entry * 1046dlcheck(void *handle) 1047{ 1048 Obj_Entry *obj; 1049 1050 for (obj = obj_list; obj != NULL; obj = obj->next) 1051 if (obj == (Obj_Entry *) handle) 1052 break; 1053 1054 if (obj == NULL || obj->refcount == 0 || obj->dl_refcount == 0) { 1055 _rtld_error("Invalid shared object handle %p", handle); 1056 return NULL; 1057 } 1058 return obj; 1059} 1060 1061/* 1062 * If the given object is already in the donelist, return true. Otherwise 1063 * add the object to the list and return false. 1064 */ 1065static bool 1066donelist_check(DoneList *dlp, const Obj_Entry *obj) 1067{ 1068 unsigned int i; 1069 1070 for (i = 0; i < dlp->num_used; i++) 1071 if (dlp->objs[i] == obj) 1072 return true; 1073 /* 1074 * Our donelist allocation should always be sufficient. But if 1075 * our threads locking isn't working properly, more shared objects 1076 * could have been loaded since we allocated the list. That should 1077 * never happen, but we'll handle it properly just in case it does. 1078 */ 1079 if (dlp->num_used < dlp->num_alloc) 1080 dlp->objs[dlp->num_used++] = obj; 1081 return false; 1082} 1083 1084/* 1085 * Hash function for symbol table lookup. Don't even think about changing 1086 * this. It is specified by the System V ABI. 1087 */ 1088unsigned long 1089elf_hash(const char *name) 1090{ 1091 const unsigned char *p = (const unsigned char *) name; 1092 unsigned long h = 0; 1093 unsigned long g; 1094 1095 while (*p != '\0') { 1096 h = (h << 4) + *p++; 1097 if ((g = h & 0xf0000000) != 0) 1098 h ^= g >> 24; 1099 h &= ~g; 1100 } 1101 return h; 1102} 1103 1104/* 1105 * Find the library with the given name, and return its full pathname. 1106 * The returned string is dynamically allocated. Generates an error 1107 * message and returns NULL if the library cannot be found. 1108 * 1109 * If the second argument is non-NULL, then it refers to an already- 1110 * loaded shared object, whose library search path will be searched. 1111 * 1112 * The search order is: 1113 * LD_LIBRARY_PATH 1114 * rpath in the referencing file 1115 * ldconfig hints 1116 * /lib:/usr/lib 1117 */ 1118static char * 1119find_library(const char *xname, const Obj_Entry *refobj) 1120{ 1121 char *pathname; 1122 char *name; 1123 1124 if (strchr(xname, '/') != NULL) { /* Hard coded pathname */ 1125 if (xname[0] != '/' && !trust) { 1126 _rtld_error("Absolute pathname required for shared object \"%s\"", 1127 xname); 1128 return NULL; 1129 } 1130 if (refobj != NULL && refobj->z_origin) 1131 return origin_subst(xname, refobj->origin_path); 1132 else 1133 return xstrdup(xname); 1134 } 1135 1136 if (libmap_disable || (refobj == NULL) || 1137 (name = lm_find(refobj->path, xname)) == NULL) 1138 name = (char *)xname; 1139 1140 dbg(" Searching for \"%s\"", name); 1141 1142 if ((pathname = search_library_path(name, ld_library_path)) != NULL || 1143 (refobj != NULL && 1144 (pathname = search_library_path(name, refobj->rpath)) != NULL) || 1145 (pathname = search_library_path(name, gethints())) != NULL || 1146 (pathname = search_library_path(name, STANDARD_LIBRARY_PATH)) != NULL) 1147 return pathname; 1148 1149 if(refobj != NULL && refobj->path != NULL) { 1150 _rtld_error("Shared object \"%s\" not found, required by \"%s\"", 1151 name, basename(refobj->path)); 1152 } else { 1153 _rtld_error("Shared object \"%s\" not found", name); 1154 } 1155 return NULL; 1156} 1157 1158/* 1159 * Given a symbol number in a referencing object, find the corresponding 1160 * definition of the symbol. Returns a pointer to the symbol, or NULL if 1161 * no definition was found. Returns a pointer to the Obj_Entry of the 1162 * defining object via the reference parameter DEFOBJ_OUT. 1163 */ 1164const Elf_Sym * 1165find_symdef(unsigned long symnum, const Obj_Entry *refobj, 1166 const Obj_Entry **defobj_out, int flags, SymCache *cache) 1167{ 1168 const Elf_Sym *ref; 1169 const Elf_Sym *def; 1170 const Obj_Entry *defobj; 1171 const Ver_Entry *ventry; 1172 const char *name; 1173 unsigned long hash; 1174 1175 /* 1176 * If we have already found this symbol, get the information from 1177 * the cache. 1178 */ 1179 if (symnum >= refobj->nchains) 1180 return NULL; /* Bad object */ 1181 if (cache != NULL && cache[symnum].sym != NULL) { 1182 *defobj_out = cache[symnum].obj; 1183 return cache[symnum].sym; 1184 } 1185 1186 ref = refobj->symtab + symnum; 1187 name = refobj->strtab + ref->st_name; 1188 defobj = NULL; 1189 1190 /* 1191 * We don't have to do a full scale lookup if the symbol is local. 1192 * We know it will bind to the instance in this load module; to 1193 * which we already have a pointer (ie ref). By not doing a lookup, 1194 * we not only improve performance, but it also avoids unresolvable 1195 * symbols when local symbols are not in the hash table. This has 1196 * been seen with the ia64 toolchain. 1197 */ 1198 if (ELF_ST_BIND(ref->st_info) != STB_LOCAL) { 1199 if (ELF_ST_TYPE(ref->st_info) == STT_SECTION) { 1200 _rtld_error("%s: Bogus symbol table entry %lu", refobj->path, 1201 symnum); 1202 } 1203 ventry = fetch_ventry(refobj, symnum); 1204 hash = elf_hash(name); 1205 def = symlook_default(name, hash, refobj, &defobj, ventry, flags); 1206 } else { 1207 def = ref; 1208 defobj = refobj; 1209 } 1210 1211 /* 1212 * If we found no definition and the reference is weak, treat the 1213 * symbol as having the value zero. 1214 */ 1215 if (def == NULL && ELF_ST_BIND(ref->st_info) == STB_WEAK) { 1216 def = &sym_zero; 1217 defobj = obj_main; 1218 } 1219 1220 if (def != NULL) { 1221 *defobj_out = defobj; 1222 /* Record the information in the cache to avoid subsequent lookups. */ 1223 if (cache != NULL) { 1224 cache[symnum].sym = def; 1225 cache[symnum].obj = defobj; 1226 } 1227 } else { 1228 if (refobj != &obj_rtld) 1229 _rtld_error("%s: Undefined symbol \"%s\"", refobj->path, name); 1230 } 1231 return def; 1232} 1233 1234/* 1235 * Return the search path from the ldconfig hints file, reading it if 1236 * necessary. Returns NULL if there are problems with the hints file, 1237 * or if the search path there is empty. 1238 */ 1239static const char * 1240gethints(void) 1241{ 1242 static char *hints; 1243 1244 if (hints == NULL) { 1245 int fd; 1246 struct elfhints_hdr hdr; 1247 char *p; 1248 1249 /* Keep from trying again in case the hints file is bad. */ 1250 hints = ""; 1251 1252 if ((fd = open(ld_elf_hints_path, O_RDONLY)) == -1) 1253 return NULL; 1254 if (read(fd, &hdr, sizeof hdr) != sizeof hdr || 1255 hdr.magic != ELFHINTS_MAGIC || 1256 hdr.version != 1) { 1257 close(fd); 1258 return NULL; 1259 } 1260 p = xmalloc(hdr.dirlistlen + 1); 1261 if (lseek(fd, hdr.strtab + hdr.dirlist, SEEK_SET) == -1 || 1262 read(fd, p, hdr.dirlistlen + 1) != (ssize_t)hdr.dirlistlen + 1) { 1263 free(p); 1264 close(fd); 1265 return NULL; 1266 } 1267 hints = p; 1268 close(fd); 1269 } 1270 return hints[0] != '\0' ? hints : NULL; 1271} 1272 1273static void 1274init_dag(Obj_Entry *root) 1275{ 1276 DoneList donelist; 1277 1278 donelist_init(&donelist); 1279 init_dag1(root, root, &donelist); 1280} 1281 1282static void 1283init_dag1(Obj_Entry *root, Obj_Entry *obj, DoneList *dlp) 1284{ 1285 const Needed_Entry *needed; 1286 1287 if (donelist_check(dlp, obj)) 1288 return; 1289 1290 obj->refcount++; 1291 objlist_push_tail(&obj->dldags, root); 1292 objlist_push_tail(&root->dagmembers, obj); 1293 for (needed = obj->needed; needed != NULL; needed = needed->next) 1294 if (needed->obj != NULL) 1295 init_dag1(root, needed->obj, dlp); 1296} 1297 1298/* 1299 * Initialize the dynamic linker. The argument is the address at which 1300 * the dynamic linker has been mapped into memory. The primary task of 1301 * this function is to relocate the dynamic linker. 1302 */ 1303static void 1304init_rtld(caddr_t mapbase, Elf_Auxinfo **aux_info) 1305{ 1306 Obj_Entry objtmp; /* Temporary rtld object */ 1307 const Elf_Dyn *dyn_rpath; 1308 const Elf_Dyn *dyn_soname; 1309 1310 /* 1311 * Conjure up an Obj_Entry structure for the dynamic linker. 1312 * 1313 * The "path" member can't be initialized yet because string constants 1314 * cannot yet be accessed. Below we will set it correctly. 1315 */ 1316 memset(&objtmp, 0, sizeof(objtmp)); 1317 objtmp.path = NULL; 1318 objtmp.rtld = true; 1319 objtmp.mapbase = mapbase; 1320#ifdef PIC 1321 objtmp.relocbase = mapbase; 1322#endif 1323 if (RTLD_IS_DYNAMIC()) { 1324 objtmp.dynamic = rtld_dynamic(&objtmp); 1325 digest_dynamic1(&objtmp, 1, &dyn_rpath, &dyn_soname); 1326 assert(objtmp.needed == NULL); 1327#if !defined(__mips__) 1328 /* MIPS and SH{3,5} have a bogus DT_TEXTREL. */ 1329 assert(!objtmp.textrel); 1330#endif 1331 1332 /* 1333 * Temporarily put the dynamic linker entry into the object list, so 1334 * that symbols can be found. 1335 */ 1336 1337 relocate_objects(&objtmp, true, &objtmp); 1338 } 1339 1340 /* Initialize the object list. */ 1341 obj_tail = &obj_list; 1342 1343 /* Now that non-local variables can be accesses, copy out obj_rtld. */ 1344 memcpy(&obj_rtld, &objtmp, sizeof(obj_rtld)); 1345 1346 if (aux_info[AT_PAGESZ] != NULL) 1347 pagesize = aux_info[AT_PAGESZ]->a_un.a_val; 1348 if (aux_info[AT_OSRELDATE] != NULL) 1349 osreldate = aux_info[AT_OSRELDATE]->a_un.a_val; 1350 1351 digest_dynamic2(&obj_rtld, dyn_rpath, dyn_soname); 1352 1353 /* Replace the path with a dynamically allocated copy. */ 1354 obj_rtld.path = xstrdup(PATH_RTLD); 1355 1356 r_debug.r_brk = r_debug_state; 1357 r_debug.r_state = RT_CONSISTENT; 1358} 1359 1360/* 1361 * Add the init functions from a needed object list (and its recursive 1362 * needed objects) to "list". This is not used directly; it is a helper 1363 * function for initlist_add_objects(). The write lock must be held 1364 * when this function is called. 1365 */ 1366static void 1367initlist_add_neededs(Needed_Entry *needed, Objlist *list) 1368{ 1369 /* Recursively process the successor needed objects. */ 1370 if (needed->next != NULL) 1371 initlist_add_neededs(needed->next, list); 1372 1373 /* Process the current needed object. */ 1374 if (needed->obj != NULL) 1375 initlist_add_objects(needed->obj, &needed->obj->next, list); 1376} 1377 1378/* 1379 * Scan all of the DAGs rooted in the range of objects from "obj" to 1380 * "tail" and add their init functions to "list". This recurses over 1381 * the DAGs and ensure the proper init ordering such that each object's 1382 * needed libraries are initialized before the object itself. At the 1383 * same time, this function adds the objects to the global finalization 1384 * list "list_fini" in the opposite order. The write lock must be 1385 * held when this function is called. 1386 */ 1387static void 1388initlist_add_objects(Obj_Entry *obj, Obj_Entry **tail, Objlist *list) 1389{ 1390 if (obj->init_scanned || obj->init_done) 1391 return; 1392 obj->init_scanned = true; 1393 1394 /* Recursively process the successor objects. */ 1395 if (&obj->next != tail) 1396 initlist_add_objects(obj->next, tail, list); 1397 1398 /* Recursively process the needed objects. */ 1399 if (obj->needed != NULL) 1400 initlist_add_neededs(obj->needed, list); 1401 1402 /* Add the object to the init list. */ 1403 if (obj->init != (Elf_Addr)NULL) 1404 objlist_push_tail(list, obj); 1405 1406 /* Add the object to the global fini list in the reverse order. */ 1407 if (obj->fini != (Elf_Addr)NULL && !obj->on_fini_list) { 1408 objlist_push_head(&list_fini, obj); 1409 obj->on_fini_list = true; 1410 } 1411} 1412 1413#ifndef FPTR_TARGET 1414#define FPTR_TARGET(f) ((Elf_Addr) (f)) 1415#endif 1416 1417/* 1418 * Given a shared object, traverse its list of needed objects, and load 1419 * each of them. Returns 0 on success. Generates an error message and 1420 * returns -1 on failure. 1421 */ 1422static int 1423load_needed_objects(Obj_Entry *first, int flags) 1424{ 1425 Obj_Entry *obj, *obj1; 1426 1427 for (obj = first; obj != NULL; obj = obj->next) { 1428 Needed_Entry *needed; 1429 1430 for (needed = obj->needed; needed != NULL; needed = needed->next) { 1431 obj1 = needed->obj = load_object(obj->strtab + needed->name, obj, 1432 flags & ~RTLD_LO_NOLOAD); 1433 if (obj1 == NULL && !ld_tracing) 1434 return -1; 1435 if (obj1 != NULL && obj1->z_nodelete && !obj1->ref_nodel) { 1436 dbg("obj %s nodelete", obj1->path); 1437 init_dag(obj1); 1438 ref_dag(obj1); 1439 obj1->ref_nodel = true; 1440 } 1441 } 1442 } 1443 1444 return 0; 1445} 1446 1447static int 1448load_preload_objects(void) 1449{ 1450 char *p = ld_preload; 1451 static const char delim[] = " \t:;"; 1452 1453 if (p == NULL) 1454 return 0; 1455 1456 p += strspn(p, delim); 1457 while (*p != '\0') { 1458 size_t len = strcspn(p, delim); 1459 char savech; 1460 1461 savech = p[len]; 1462 p[len] = '\0'; 1463 if (load_object(p, NULL, 0) == NULL) 1464 return -1; /* XXX - cleanup */ 1465 p[len] = savech; 1466 p += len; 1467 p += strspn(p, delim); 1468 } 1469 LD_UTRACE(UTRACE_PRELOAD_FINISHED, NULL, NULL, 0, 0, NULL); 1470 return 0; 1471} 1472 1473/* 1474 * Load a shared object into memory, if it is not already loaded. 1475 * 1476 * Returns a pointer to the Obj_Entry for the object. Returns NULL 1477 * on failure. 1478 */ 1479static Obj_Entry * 1480load_object(const char *name, const Obj_Entry *refobj, int flags) 1481{ 1482 Obj_Entry *obj; 1483 int fd = -1; 1484 struct stat sb; 1485 char *path; 1486 1487 for (obj = obj_list->next; obj != NULL; obj = obj->next) 1488 if (object_match_name(obj, name)) 1489 return obj; 1490 1491 path = find_library(name, refobj); 1492 if (path == NULL) 1493 return NULL; 1494 1495 /* 1496 * If we didn't find a match by pathname, open the file and check 1497 * again by device and inode. This avoids false mismatches caused 1498 * by multiple links or ".." in pathnames. 1499 * 1500 * To avoid a race, we open the file and use fstat() rather than 1501 * using stat(). 1502 */ 1503 if ((fd = open(path, O_RDONLY)) == -1) { 1504 _rtld_error("Cannot open \"%s\"", path); 1505 free(path); 1506 return NULL; 1507 } 1508 if (fstat(fd, &sb) == -1) { 1509 _rtld_error("Cannot fstat \"%s\"", path); 1510 close(fd); 1511 free(path); 1512 return NULL; 1513 } 1514 for (obj = obj_list->next; obj != NULL; obj = obj->next) { 1515 if (obj->ino == sb.st_ino && obj->dev == sb.st_dev) { 1516 close(fd); 1517 break; 1518 } 1519 } 1520 if (obj != NULL) { 1521 object_add_name(obj, name); 1522 free(path); 1523 close(fd); 1524 return obj; 1525 } 1526 if (flags & RTLD_LO_NOLOAD) { 1527 free(path); 1528 return (NULL); 1529 } 1530 1531 /* First use of this object, so we must map it in */ 1532 obj = do_load_object(fd, name, path, &sb, flags); 1533 if (obj == NULL) 1534 free(path); 1535 close(fd); 1536 1537 return obj; 1538} 1539 1540static Obj_Entry * 1541do_load_object(int fd, const char *name, char *path, struct stat *sbp, 1542 int flags) 1543{ 1544 Obj_Entry *obj; 1545 struct statfs fs; 1546 1547 /* 1548 * but first, make sure that environment variables haven't been 1549 * used to circumvent the noexec flag on a filesystem. 1550 */ 1551 if (dangerous_ld_env) { 1552 if (fstatfs(fd, &fs) != 0) { 1553 _rtld_error("Cannot fstatfs \"%s\"", path); 1554 return NULL; 1555 } 1556 if (fs.f_flags & MNT_NOEXEC) { 1557 _rtld_error("Cannot execute objects on %s\n", fs.f_mntonname); 1558 return NULL; 1559 } 1560 } 1561 dbg("loading \"%s\"", path); 1562 obj = map_object(fd, path, sbp); 1563 if (obj == NULL) 1564 return NULL; 1565 1566 object_add_name(obj, name); 1567 obj->path = path; 1568 digest_dynamic(obj, 0); 1569 if (obj->z_noopen && (flags & (RTLD_LO_DLOPEN | RTLD_LO_TRACE)) == 1570 RTLD_LO_DLOPEN) { 1571 dbg("refusing to load non-loadable \"%s\"", obj->path); 1572 _rtld_error("Cannot dlopen non-loadable %s", obj->path); 1573 munmap(obj->mapbase, obj->mapsize); 1574 obj_free(obj); 1575 return (NULL); 1576 } 1577 1578 *obj_tail = obj; 1579 obj_tail = &obj->next; 1580 obj_count++; 1581 obj_loads++; 1582 linkmap_add(obj); /* for GDB & dlinfo() */ 1583 1584 dbg(" %p .. %p: %s", obj->mapbase, 1585 obj->mapbase + obj->mapsize - 1, obj->path); 1586 if (obj->textrel) 1587 dbg(" WARNING: %s has impure text", obj->path); 1588 LD_UTRACE(UTRACE_LOAD_OBJECT, obj, obj->mapbase, obj->mapsize, 0, 1589 obj->path); 1590 1591 return obj; 1592} 1593 1594static Obj_Entry * 1595obj_from_addr(const void *addr) 1596{ 1597 Obj_Entry *obj; 1598 1599 for (obj = obj_list; obj != NULL; obj = obj->next) { 1600 if (addr < (void *) obj->mapbase) 1601 continue; 1602 if (addr < (void *) (obj->mapbase + obj->mapsize)) 1603 return obj; 1604 } 1605 return NULL; 1606} 1607 1608/* 1609 * Call the finalization functions for each of the objects in "list" 1610 * which are unreferenced. All of the objects are expected to have 1611 * non-NULL fini functions. 1612 */ 1613static void 1614objlist_call_fini(Objlist *list, bool force, int *lockstate) 1615{ 1616 Objlist_Entry *elm, *elm_tmp; 1617 char *saved_msg; 1618 1619 /* 1620 * Preserve the current error message since a fini function might 1621 * call into the dynamic linker and overwrite it. 1622 */ 1623 saved_msg = errmsg_save(); 1624 STAILQ_FOREACH_SAFE(elm, list, link, elm_tmp) { 1625 if (elm->obj->refcount == 0 || force) { 1626 dbg("calling fini function for %s at %p", elm->obj->path, 1627 (void *)elm->obj->fini); 1628 LD_UTRACE(UTRACE_FINI_CALL, elm->obj, (void *)elm->obj->fini, 0, 0, 1629 elm->obj->path); 1630 /* Remove object from fini list to prevent recursive invocation. */ 1631 STAILQ_REMOVE(list, elm, Struct_Objlist_Entry, link); 1632 wlock_release(rtld_bind_lock, *lockstate); 1633 call_initfini_pointer(elm->obj, elm->obj->fini); 1634 *lockstate = wlock_acquire(rtld_bind_lock); 1635 /* No need to free anything if process is going down. */ 1636 if (!force) 1637 free(elm); 1638 } 1639 } 1640 errmsg_restore(saved_msg); 1641} 1642 1643/* 1644 * Call the initialization functions for each of the objects in 1645 * "list". All of the objects are expected to have non-NULL init 1646 * functions. 1647 */ 1648static void 1649objlist_call_init(Objlist *list, int *lockstate) 1650{ 1651 Objlist_Entry *elm; 1652 Obj_Entry *obj; 1653 char *saved_msg; 1654 1655 /* 1656 * Clean init_scanned flag so that objects can be rechecked and 1657 * possibly initialized earlier if any of vectors called below 1658 * cause the change by using dlopen. 1659 */ 1660 for (obj = obj_list; obj != NULL; obj = obj->next) 1661 obj->init_scanned = false; 1662 1663 /* 1664 * Preserve the current error message since an init function might 1665 * call into the dynamic linker and overwrite it. 1666 */ 1667 saved_msg = errmsg_save(); 1668 STAILQ_FOREACH(elm, list, link) { 1669 if (elm->obj->init_done) /* Initialized early. */ 1670 continue; 1671 dbg("calling init function for %s at %p", elm->obj->path, 1672 (void *)elm->obj->init); 1673 LD_UTRACE(UTRACE_INIT_CALL, elm->obj, (void *)elm->obj->init, 0, 0, 1674 elm->obj->path); 1675 /* 1676 * Race: other thread might try to use this object before current 1677 * one completes the initilization. Not much can be done here 1678 * without better locking. 1679 */ 1680 elm->obj->init_done = true; 1681 wlock_release(rtld_bind_lock, *lockstate); 1682 call_initfini_pointer(elm->obj, elm->obj->init); 1683 *lockstate = wlock_acquire(rtld_bind_lock); 1684 } 1685 errmsg_restore(saved_msg); 1686} 1687 1688static void 1689objlist_clear(Objlist *list) 1690{ 1691 Objlist_Entry *elm; 1692 1693 while (!STAILQ_EMPTY(list)) { 1694 elm = STAILQ_FIRST(list); 1695 STAILQ_REMOVE_HEAD(list, link); 1696 free(elm); 1697 } 1698} 1699 1700static Objlist_Entry * 1701objlist_find(Objlist *list, const Obj_Entry *obj) 1702{ 1703 Objlist_Entry *elm; 1704 1705 STAILQ_FOREACH(elm, list, link) 1706 if (elm->obj == obj) 1707 return elm; 1708 return NULL; 1709} 1710 1711static void 1712objlist_init(Objlist *list) 1713{ 1714 STAILQ_INIT(list); 1715} 1716 1717static void 1718objlist_push_head(Objlist *list, Obj_Entry *obj) 1719{ 1720 Objlist_Entry *elm; 1721 1722 elm = NEW(Objlist_Entry); 1723 elm->obj = obj; 1724 STAILQ_INSERT_HEAD(list, elm, link); 1725} 1726 1727static void 1728objlist_push_tail(Objlist *list, Obj_Entry *obj) 1729{ 1730 Objlist_Entry *elm; 1731 1732 elm = NEW(Objlist_Entry); 1733 elm->obj = obj; 1734 STAILQ_INSERT_TAIL(list, elm, link); 1735} 1736 1737static void 1738objlist_remove(Objlist *list, Obj_Entry *obj) 1739{ 1740 Objlist_Entry *elm; 1741 1742 if ((elm = objlist_find(list, obj)) != NULL) { 1743 STAILQ_REMOVE(list, elm, Struct_Objlist_Entry, link); 1744 free(elm); 1745 } 1746} 1747 1748/* 1749 * Relocate newly-loaded shared objects. The argument is a pointer to 1750 * the Obj_Entry for the first such object. All objects from the first 1751 * to the end of the list of objects are relocated. Returns 0 on success, 1752 * or -1 on failure. 1753 */ 1754static int 1755relocate_objects(Obj_Entry *first, bool bind_now, Obj_Entry *rtldobj) 1756{ 1757 Obj_Entry *obj; 1758 1759 for (obj = first; obj != NULL; obj = obj->next) { 1760 if (obj != rtldobj) 1761 dbg("relocating \"%s\"", obj->path); 1762 if (obj->nbuckets == 0 || obj->nchains == 0 || obj->buckets == NULL || 1763 obj->symtab == NULL || obj->strtab == NULL) { 1764 _rtld_error("%s: Shared object has no run-time symbol table", 1765 obj->path); 1766 return -1; 1767 } 1768 1769 if (obj->textrel) { 1770 /* There are relocations to the write-protected text segment. */ 1771 if (mprotect(obj->mapbase, obj->textsize, 1772 PROT_READ|PROT_WRITE|PROT_EXEC) == -1) { 1773 _rtld_error("%s: Cannot write-enable text segment: %s", 1774 obj->path, strerror(errno)); 1775 return -1; 1776 } 1777 } 1778 1779 /* Process the non-PLT relocations. */ 1780 if (reloc_non_plt(obj, rtldobj)) 1781 return -1; 1782 1783 if (obj->textrel) { /* Re-protected the text segment. */ 1784 if (mprotect(obj->mapbase, obj->textsize, 1785 PROT_READ|PROT_EXEC) == -1) { 1786 _rtld_error("%s: Cannot write-protect text segment: %s", 1787 obj->path, strerror(errno)); 1788 return -1; 1789 } 1790 } 1791 1792 /* Process the PLT relocations. */ 1793 if (reloc_plt(obj) == -1) 1794 return -1; 1795 /* Relocate the jump slots if we are doing immediate binding. */ 1796 if (obj->bind_now || bind_now) 1797 if (reloc_jmpslots(obj) == -1) 1798 return -1; 1799 1800 1801 /* 1802 * Set up the magic number and version in the Obj_Entry. These 1803 * were checked in the crt1.o from the original ElfKit, so we 1804 * set them for backward compatibility. 1805 */ 1806 obj->magic = RTLD_MAGIC; 1807 obj->version = RTLD_VERSION; 1808 1809 /* Set the special PLT or GOT entries. */ 1810 init_pltgot(obj); 1811 } 1812 1813 return 0; 1814} 1815 1816/* 1817 * Cleanup procedure. It will be called (by the atexit mechanism) just 1818 * before the process exits. 1819 */ 1820static void 1821rtld_exit(void) 1822{ 1823 int lockstate; 1824 1825 lockstate = wlock_acquire(rtld_bind_lock); 1826 dbg("rtld_exit()"); 1827 objlist_call_fini(&list_fini, true, &lockstate); 1828 /* No need to remove the items from the list, since we are exiting. */ 1829 if (!libmap_disable) 1830 lm_fini(); 1831 wlock_release(rtld_bind_lock, lockstate); 1832} 1833 1834static void * 1835path_enumerate(const char *path, path_enum_proc callback, void *arg) 1836{ 1837#ifdef COMPAT_32BIT 1838 const char *trans; 1839#endif 1840 if (path == NULL) 1841 return (NULL); 1842 1843 path += strspn(path, ":;"); 1844 while (*path != '\0') { 1845 size_t len; 1846 char *res; 1847 1848 len = strcspn(path, ":;"); 1849#ifdef COMPAT_32BIT 1850 trans = lm_findn(NULL, path, len); 1851 if (trans) 1852 res = callback(trans, strlen(trans), arg); 1853 else 1854#endif 1855 res = callback(path, len, arg); 1856 1857 if (res != NULL) 1858 return (res); 1859 1860 path += len; 1861 path += strspn(path, ":;"); 1862 } 1863 1864 return (NULL); 1865} 1866 1867struct try_library_args { 1868 const char *name; 1869 size_t namelen; 1870 char *buffer; 1871 size_t buflen; 1872}; 1873 1874static void * 1875try_library_path(const char *dir, size_t dirlen, void *param) 1876{ 1877 struct try_library_args *arg; 1878 1879 arg = param; 1880 if (*dir == '/' || trust) { 1881 char *pathname; 1882 1883 if (dirlen + 1 + arg->namelen + 1 > arg->buflen) 1884 return (NULL); 1885 1886 pathname = arg->buffer; 1887 strncpy(pathname, dir, dirlen); 1888 pathname[dirlen] = '/'; 1889 strcpy(pathname + dirlen + 1, arg->name); 1890 1891 dbg(" Trying \"%s\"", pathname); 1892 if (access(pathname, F_OK) == 0) { /* We found it */ 1893 pathname = xmalloc(dirlen + 1 + arg->namelen + 1); 1894 strcpy(pathname, arg->buffer); 1895 return (pathname); 1896 } 1897 } 1898 return (NULL); 1899} 1900 1901static char * 1902search_library_path(const char *name, const char *path) 1903{ 1904 char *p; 1905 struct try_library_args arg; 1906 1907 if (path == NULL) 1908 return NULL; 1909 1910 arg.name = name; 1911 arg.namelen = strlen(name); 1912 arg.buffer = xmalloc(PATH_MAX); 1913 arg.buflen = PATH_MAX; 1914 1915 p = path_enumerate(path, try_library_path, &arg); 1916 1917 free(arg.buffer); 1918 1919 return (p); 1920} 1921 1922int 1923dlclose(void *handle) 1924{ 1925 Obj_Entry *root; 1926 int lockstate; 1927 1928 lockstate = wlock_acquire(rtld_bind_lock); 1929 root = dlcheck(handle); 1930 if (root == NULL) { 1931 wlock_release(rtld_bind_lock, lockstate); 1932 return -1; 1933 } 1934 LD_UTRACE(UTRACE_DLCLOSE_START, handle, NULL, 0, root->dl_refcount, 1935 root->path); 1936 1937 /* Unreference the object and its dependencies. */ 1938 root->dl_refcount--; 1939 1940 unref_dag(root); 1941 1942 if (root->refcount == 0) { 1943 /* 1944 * The object is no longer referenced, so we must unload it. 1945 * First, call the fini functions. 1946 */ 1947 objlist_call_fini(&list_fini, false, &lockstate); 1948 1949 /* Finish cleaning up the newly-unreferenced objects. */ 1950 GDB_STATE(RT_DELETE,&root->linkmap); 1951 unload_object(root); 1952 GDB_STATE(RT_CONSISTENT,NULL); 1953 } 1954 LD_UTRACE(UTRACE_DLCLOSE_STOP, handle, NULL, 0, 0, NULL); 1955 wlock_release(rtld_bind_lock, lockstate); 1956 return 0; 1957} 1958 1959char * 1960dlerror(void) 1961{ 1962 char *msg = error_message; 1963 error_message = NULL; 1964 return msg; 1965} 1966 1967/* 1968 * This function is deprecated and has no effect. 1969 */ 1970void 1971dllockinit(void *context, 1972 void *(*lock_create)(void *context), 1973 void (*rlock_acquire)(void *lock), 1974 void (*wlock_acquire)(void *lock), 1975 void (*lock_release)(void *lock), 1976 void (*lock_destroy)(void *lock), 1977 void (*context_destroy)(void *context)) 1978{ 1979 static void *cur_context; 1980 static void (*cur_context_destroy)(void *); 1981 1982 /* Just destroy the context from the previous call, if necessary. */ 1983 if (cur_context_destroy != NULL) 1984 cur_context_destroy(cur_context); 1985 cur_context = context; 1986 cur_context_destroy = context_destroy; 1987} 1988 1989void * 1990dlopen(const char *name, int mode) 1991{ 1992 Obj_Entry **old_obj_tail; 1993 Obj_Entry *obj; 1994 Objlist initlist; 1995 int result, lockstate, nodelete, lo_flags; 1996 1997 LD_UTRACE(UTRACE_DLOPEN_START, NULL, NULL, 0, mode, name); 1998 ld_tracing = (mode & RTLD_TRACE) == 0 ? NULL : "1"; 1999 if (ld_tracing != NULL) 2000 environ = (char **)*get_program_var_addr("environ"); 2001 nodelete = mode & RTLD_NODELETE; 2002 lo_flags = RTLD_LO_DLOPEN; 2003 if (mode & RTLD_NOLOAD) 2004 lo_flags |= RTLD_LO_NOLOAD; 2005 if (ld_tracing != NULL) 2006 lo_flags |= RTLD_LO_TRACE; 2007 2008 objlist_init(&initlist); 2009 2010 lockstate = wlock_acquire(rtld_bind_lock); 2011 GDB_STATE(RT_ADD,NULL); 2012 2013 old_obj_tail = obj_tail; 2014 obj = NULL; 2015 if (name == NULL) { 2016 obj = obj_main; 2017 obj->refcount++; 2018 } else { 2019 obj = load_object(name, obj_main, lo_flags); 2020 } 2021 2022 if (obj) { 2023 obj->dl_refcount++; 2024 if (mode & RTLD_GLOBAL && objlist_find(&list_global, obj) == NULL) 2025 objlist_push_tail(&list_global, obj); 2026 mode &= RTLD_MODEMASK; 2027 if (*old_obj_tail != NULL) { /* We loaded something new. */ 2028 assert(*old_obj_tail == obj); 2029 result = load_needed_objects(obj, RTLD_LO_DLOPEN); 2030 init_dag(obj); 2031 if (result != -1) 2032 result = rtld_verify_versions(&obj->dagmembers); 2033 if (result != -1 && ld_tracing) 2034 goto trace; 2035 if (result == -1 || 2036 (relocate_objects(obj, mode == RTLD_NOW, &obj_rtld)) == -1) { 2037 obj->dl_refcount--; 2038 unref_dag(obj); 2039 if (obj->refcount == 0) 2040 unload_object(obj); 2041 obj = NULL; 2042 } else { 2043 /* Make list of init functions to call. */ 2044 initlist_add_objects(obj, &obj->next, &initlist); 2045 } 2046 } else { 2047 2048 /* Bump the reference counts for objects on this DAG. */ 2049 ref_dag(obj); 2050 2051 if (ld_tracing) 2052 goto trace; 2053 } 2054 if (obj != NULL && (nodelete || obj->z_nodelete) && !obj->ref_nodel) { 2055 dbg("obj %s nodelete", obj->path); 2056 ref_dag(obj); 2057 obj->z_nodelete = obj->ref_nodel = true; 2058 } 2059 } 2060 2061 LD_UTRACE(UTRACE_DLOPEN_STOP, obj, NULL, 0, obj ? obj->dl_refcount : 0, 2062 name); 2063 GDB_STATE(RT_CONSISTENT,obj ? &obj->linkmap : NULL); 2064 2065 /* Call the init functions. */ 2066 objlist_call_init(&initlist, &lockstate); 2067 objlist_clear(&initlist); 2068 wlock_release(rtld_bind_lock, lockstate); 2069 return obj; 2070trace: 2071 trace_loaded_objects(obj); 2072 wlock_release(rtld_bind_lock, lockstate); 2073 exit(0); 2074} 2075 2076static void * 2077do_dlsym(void *handle, const char *name, void *retaddr, const Ver_Entry *ve, 2078 int flags) 2079{ 2080 DoneList donelist; 2081 const Obj_Entry *obj, *defobj; 2082 const Elf_Sym *def, *symp; 2083 unsigned long hash; 2084 int lockstate; 2085 2086 hash = elf_hash(name); 2087 def = NULL; 2088 defobj = NULL; 2089 flags |= SYMLOOK_IN_PLT; 2090 2091 lockstate = rlock_acquire(rtld_bind_lock); 2092 if (handle == NULL || handle == RTLD_NEXT || 2093 handle == RTLD_DEFAULT || handle == RTLD_SELF) { 2094 2095 if ((obj = obj_from_addr(retaddr)) == NULL) { 2096 _rtld_error("Cannot determine caller's shared object"); 2097 rlock_release(rtld_bind_lock, lockstate); 2098 return NULL; 2099 } 2100 if (handle == NULL) { /* Just the caller's shared object. */ 2101 def = symlook_obj(name, hash, obj, ve, flags); 2102 defobj = obj; 2103 } else if (handle == RTLD_NEXT || /* Objects after caller's */ 2104 handle == RTLD_SELF) { /* ... caller included */ 2105 if (handle == RTLD_NEXT) 2106 obj = obj->next; 2107 for (; obj != NULL; obj = obj->next) { 2108 if ((symp = symlook_obj(name, hash, obj, ve, flags)) != NULL) { 2109 if (def == NULL || ELF_ST_BIND(symp->st_info) != STB_WEAK) { 2110 def = symp; 2111 defobj = obj; 2112 if (ELF_ST_BIND(def->st_info) != STB_WEAK) 2113 break; 2114 } 2115 } 2116 } 2117 /* 2118 * Search the dynamic linker itself, and possibly resolve the 2119 * symbol from there. This is how the application links to 2120 * dynamic linker services such as dlopen. 2121 */ 2122 if (def == NULL || ELF_ST_BIND(def->st_info) == STB_WEAK) { 2123 symp = symlook_obj(name, hash, &obj_rtld, ve, flags); 2124 if (symp != NULL) { 2125 def = symp; 2126 defobj = &obj_rtld; 2127 } 2128 } 2129 } else { 2130 assert(handle == RTLD_DEFAULT); 2131 def = symlook_default(name, hash, obj, &defobj, ve, flags); 2132 } 2133 } else { 2134 if ((obj = dlcheck(handle)) == NULL) { 2135 rlock_release(rtld_bind_lock, lockstate); 2136 return NULL; 2137 } 2138 2139 donelist_init(&donelist); 2140 if (obj->mainprog) { 2141 /* Search main program and all libraries loaded by it. */ 2142 def = symlook_list(name, hash, &list_main, &defobj, ve, flags, 2143 &donelist); 2144 2145 /* 2146 * We do not distinguish between 'main' object and global scope. 2147 * If symbol is not defined by objects loaded at startup, continue 2148 * search among dynamically loaded objects with RTLD_GLOBAL 2149 * scope. 2150 */ 2151 if (def == NULL) 2152 def = symlook_list(name, hash, &list_global, &defobj, ve, 2153 flags, &donelist); 2154 } else { 2155 Needed_Entry fake; 2156 2157 /* Search the whole DAG rooted at the given object. */ 2158 fake.next = NULL; 2159 fake.obj = (Obj_Entry *)obj; 2160 fake.name = 0; 2161 def = symlook_needed(name, hash, &fake, &defobj, ve, flags, 2162 &donelist); 2163 } 2164 } 2165 2166 if (def != NULL) { 2167 rlock_release(rtld_bind_lock, lockstate); 2168 2169 /* 2170 * The value required by the caller is derived from the value 2171 * of the symbol. For the ia64 architecture, we need to 2172 * construct a function descriptor which the caller can use to 2173 * call the function with the right 'gp' value. For other 2174 * architectures and for non-functions, the value is simply 2175 * the relocated value of the symbol. 2176 */ 2177 if (ELF_ST_TYPE(def->st_info) == STT_FUNC) 2178 return make_function_pointer(def, defobj); 2179 else 2180 return defobj->relocbase + def->st_value; 2181 } 2182 2183 _rtld_error("Undefined symbol \"%s\"", name); 2184 rlock_release(rtld_bind_lock, lockstate); 2185 return NULL; 2186} 2187 2188void * 2189dlsym(void *handle, const char *name) 2190{ 2191 return do_dlsym(handle, name, __builtin_return_address(0), NULL, 2192 SYMLOOK_DLSYM); 2193} 2194 2195dlfunc_t 2196dlfunc(void *handle, const char *name) 2197{ 2198 union { 2199 void *d; 2200 dlfunc_t f; 2201 } rv; 2202 2203 rv.d = do_dlsym(handle, name, __builtin_return_address(0), NULL, 2204 SYMLOOK_DLSYM); 2205 return (rv.f); 2206} 2207 2208void * 2209dlvsym(void *handle, const char *name, const char *version) 2210{ 2211 Ver_Entry ventry; 2212 2213 ventry.name = version; 2214 ventry.file = NULL; 2215 ventry.hash = elf_hash(version); 2216 ventry.flags= 0; 2217 return do_dlsym(handle, name, __builtin_return_address(0), &ventry, 2218 SYMLOOK_DLSYM); 2219} 2220 2221int 2222_rtld_addr_phdr(const void *addr, struct dl_phdr_info *phdr_info) 2223{ 2224 const Obj_Entry *obj; 2225 int lockstate; 2226 2227 lockstate = rlock_acquire(rtld_bind_lock); 2228 obj = obj_from_addr(addr); 2229 if (obj == NULL) { 2230 _rtld_error("No shared object contains address"); 2231 rlock_release(rtld_bind_lock, lockstate); 2232 return (0); 2233 } 2234 rtld_fill_dl_phdr_info(obj, phdr_info); 2235 rlock_release(rtld_bind_lock, lockstate); 2236 return (1); 2237} 2238 2239int 2240dladdr(const void *addr, Dl_info *info) 2241{ 2242 const Obj_Entry *obj; 2243 const Elf_Sym *def; 2244 void *symbol_addr; 2245 unsigned long symoffset; 2246 int lockstate; 2247 2248 lockstate = rlock_acquire(rtld_bind_lock); 2249 obj = obj_from_addr(addr); 2250 if (obj == NULL) { 2251 _rtld_error("No shared object contains address"); 2252 rlock_release(rtld_bind_lock, lockstate); 2253 return 0; 2254 } 2255 info->dli_fname = obj->path; 2256 info->dli_fbase = obj->mapbase; 2257 info->dli_saddr = (void *)0; 2258 info->dli_sname = NULL; 2259 2260 /* 2261 * Walk the symbol list looking for the symbol whose address is 2262 * closest to the address sent in. 2263 */ 2264 for (symoffset = 0; symoffset < obj->nchains; symoffset++) { 2265 def = obj->symtab + symoffset; 2266 2267 /* 2268 * For skip the symbol if st_shndx is either SHN_UNDEF or 2269 * SHN_COMMON. 2270 */ 2271 if (def->st_shndx == SHN_UNDEF || def->st_shndx == SHN_COMMON) 2272 continue; 2273 2274 /* 2275 * If the symbol is greater than the specified address, or if it 2276 * is further away from addr than the current nearest symbol, 2277 * then reject it. 2278 */ 2279 symbol_addr = obj->relocbase + def->st_value; 2280 if (symbol_addr > addr || symbol_addr < info->dli_saddr) 2281 continue; 2282 2283 /* Update our idea of the nearest symbol. */ 2284 info->dli_sname = obj->strtab + def->st_name; 2285 info->dli_saddr = symbol_addr; 2286 2287 /* Exact match? */ 2288 if (info->dli_saddr == addr) 2289 break; 2290 } 2291 rlock_release(rtld_bind_lock, lockstate); 2292 return 1; 2293} 2294 2295int 2296dlinfo(void *handle, int request, void *p) 2297{ 2298 const Obj_Entry *obj; 2299 int error, lockstate; 2300 2301 lockstate = rlock_acquire(rtld_bind_lock); 2302 2303 if (handle == NULL || handle == RTLD_SELF) { 2304 void *retaddr; 2305 2306 retaddr = __builtin_return_address(0); /* __GNUC__ only */ 2307 if ((obj = obj_from_addr(retaddr)) == NULL) 2308 _rtld_error("Cannot determine caller's shared object"); 2309 } else 2310 obj = dlcheck(handle); 2311 2312 if (obj == NULL) { 2313 rlock_release(rtld_bind_lock, lockstate); 2314 return (-1); 2315 } 2316 2317 error = 0; 2318 switch (request) { 2319 case RTLD_DI_LINKMAP: 2320 *((struct link_map const **)p) = &obj->linkmap; 2321 break; 2322 case RTLD_DI_ORIGIN: 2323 error = rtld_dirname(obj->path, p); 2324 break; 2325 2326 case RTLD_DI_SERINFOSIZE: 2327 case RTLD_DI_SERINFO: 2328 error = do_search_info(obj, request, (struct dl_serinfo *)p); 2329 break; 2330 2331 default: 2332 _rtld_error("Invalid request %d passed to dlinfo()", request); 2333 error = -1; 2334 } 2335 2336 rlock_release(rtld_bind_lock, lockstate); 2337 2338 return (error); 2339} 2340 2341static void 2342rtld_fill_dl_phdr_info(const Obj_Entry *obj, struct dl_phdr_info *phdr_info) 2343{ 2344 2345 phdr_info->dlpi_addr = (Elf_Addr)obj->relocbase; 2346 phdr_info->dlpi_name = STAILQ_FIRST(&obj->names) ? 2347 STAILQ_FIRST(&obj->names)->name : obj->path; 2348 phdr_info->dlpi_phdr = obj->phdr; 2349 phdr_info->dlpi_phnum = obj->phsize / sizeof(obj->phdr[0]); 2350 phdr_info->dlpi_tls_modid = obj->tlsindex; 2351 phdr_info->dlpi_tls_data = obj->tlsinit; 2352 phdr_info->dlpi_adds = obj_loads; 2353 phdr_info->dlpi_subs = obj_loads - obj_count; 2354} 2355 2356int 2357dl_iterate_phdr(__dl_iterate_hdr_callback callback, void *param) 2358{ 2359 struct dl_phdr_info phdr_info; 2360 const Obj_Entry *obj; 2361 int error, bind_lockstate, phdr_lockstate; 2362 2363 phdr_lockstate = wlock_acquire(rtld_phdr_lock); 2364 bind_lockstate = rlock_acquire(rtld_bind_lock); 2365 2366 error = 0; 2367 2368 for (obj = obj_list; obj != NULL; obj = obj->next) { 2369 rtld_fill_dl_phdr_info(obj, &phdr_info); 2370 if ((error = callback(&phdr_info, sizeof phdr_info, param)) != 0) 2371 break; 2372 2373 } 2374 rlock_release(rtld_bind_lock, bind_lockstate); 2375 wlock_release(rtld_phdr_lock, phdr_lockstate); 2376 2377 return (error); 2378} 2379 2380struct fill_search_info_args { 2381 int request; 2382 unsigned int flags; 2383 Dl_serinfo *serinfo; 2384 Dl_serpath *serpath; 2385 char *strspace; 2386}; 2387 2388static void * 2389fill_search_info(const char *dir, size_t dirlen, void *param) 2390{ 2391 struct fill_search_info_args *arg; 2392 2393 arg = param; 2394 2395 if (arg->request == RTLD_DI_SERINFOSIZE) { 2396 arg->serinfo->dls_cnt ++; 2397 arg->serinfo->dls_size += sizeof(Dl_serpath) + dirlen + 1; 2398 } else { 2399 struct dl_serpath *s_entry; 2400 2401 s_entry = arg->serpath; 2402 s_entry->dls_name = arg->strspace; 2403 s_entry->dls_flags = arg->flags; 2404 2405 strncpy(arg->strspace, dir, dirlen); 2406 arg->strspace[dirlen] = '\0'; 2407 2408 arg->strspace += dirlen + 1; 2409 arg->serpath++; 2410 } 2411 2412 return (NULL); 2413} 2414 2415static int 2416do_search_info(const Obj_Entry *obj, int request, struct dl_serinfo *info) 2417{ 2418 struct dl_serinfo _info; 2419 struct fill_search_info_args args; 2420 2421 args.request = RTLD_DI_SERINFOSIZE; 2422 args.serinfo = &_info; 2423 2424 _info.dls_size = __offsetof(struct dl_serinfo, dls_serpath); 2425 _info.dls_cnt = 0; 2426 2427 path_enumerate(ld_library_path, fill_search_info, &args); 2428 path_enumerate(obj->rpath, fill_search_info, &args); 2429 path_enumerate(gethints(), fill_search_info, &args); 2430 path_enumerate(STANDARD_LIBRARY_PATH, fill_search_info, &args); 2431 2432 2433 if (request == RTLD_DI_SERINFOSIZE) { 2434 info->dls_size = _info.dls_size; 2435 info->dls_cnt = _info.dls_cnt; 2436 return (0); 2437 } 2438 2439 if (info->dls_cnt != _info.dls_cnt || info->dls_size != _info.dls_size) { 2440 _rtld_error("Uninitialized Dl_serinfo struct passed to dlinfo()"); 2441 return (-1); 2442 } 2443 2444 args.request = RTLD_DI_SERINFO; 2445 args.serinfo = info; 2446 args.serpath = &info->dls_serpath[0]; 2447 args.strspace = (char *)&info->dls_serpath[_info.dls_cnt]; 2448 2449 args.flags = LA_SER_LIBPATH; 2450 if (path_enumerate(ld_library_path, fill_search_info, &args) != NULL) 2451 return (-1); 2452 2453 args.flags = LA_SER_RUNPATH; 2454 if (path_enumerate(obj->rpath, fill_search_info, &args) != NULL) 2455 return (-1); 2456 2457 args.flags = LA_SER_CONFIG; 2458 if (path_enumerate(gethints(), fill_search_info, &args) != NULL) 2459 return (-1); 2460 2461 args.flags = LA_SER_DEFAULT; 2462 if (path_enumerate(STANDARD_LIBRARY_PATH, fill_search_info, &args) != NULL) 2463 return (-1); 2464 return (0); 2465} 2466 2467static int 2468rtld_dirname(const char *path, char *bname) 2469{ 2470 const char *endp; 2471 2472 /* Empty or NULL string gets treated as "." */ 2473 if (path == NULL || *path == '\0') { 2474 bname[0] = '.'; 2475 bname[1] = '\0'; 2476 return (0); 2477 } 2478 2479 /* Strip trailing slashes */ 2480 endp = path + strlen(path) - 1; 2481 while (endp > path && *endp == '/') 2482 endp--; 2483 2484 /* Find the start of the dir */ 2485 while (endp > path && *endp != '/') 2486 endp--; 2487 2488 /* Either the dir is "/" or there are no slashes */ 2489 if (endp == path) { 2490 bname[0] = *endp == '/' ? '/' : '.'; 2491 bname[1] = '\0'; 2492 return (0); 2493 } else { 2494 do { 2495 endp--; 2496 } while (endp > path && *endp == '/'); 2497 } 2498 2499 if (endp - path + 2 > PATH_MAX) 2500 { 2501 _rtld_error("Filename is too long: %s", path); 2502 return(-1); 2503 } 2504 2505 strncpy(bname, path, endp - path + 1); 2506 bname[endp - path + 1] = '\0'; 2507 return (0); 2508} 2509 2510static int 2511rtld_dirname_abs(const char *path, char *base) 2512{ 2513 char base_rel[PATH_MAX]; 2514 2515 if (rtld_dirname(path, base) == -1) 2516 return (-1); 2517 if (base[0] == '/') 2518 return (0); 2519 if (getcwd(base_rel, sizeof(base_rel)) == NULL || 2520 strlcat(base_rel, "/", sizeof(base_rel)) >= sizeof(base_rel) || 2521 strlcat(base_rel, base, sizeof(base_rel)) >= sizeof(base_rel)) 2522 return (-1); 2523 strcpy(base, base_rel); 2524 return (0); 2525} 2526 2527static void 2528linkmap_add(Obj_Entry *obj) 2529{ 2530 struct link_map *l = &obj->linkmap; 2531 struct link_map *prev; 2532 2533 obj->linkmap.l_name = obj->path; 2534 obj->linkmap.l_addr = obj->mapbase; 2535 obj->linkmap.l_ld = obj->dynamic; 2536#ifdef __mips__ 2537 /* GDB needs load offset on MIPS to use the symbols */ 2538 obj->linkmap.l_offs = obj->relocbase; 2539#endif 2540 2541 if (r_debug.r_map == NULL) { 2542 r_debug.r_map = l; 2543 return; 2544 } 2545 2546 /* 2547 * Scan to the end of the list, but not past the entry for the 2548 * dynamic linker, which we want to keep at the very end. 2549 */ 2550 for (prev = r_debug.r_map; 2551 prev->l_next != NULL && prev->l_next != &obj_rtld.linkmap; 2552 prev = prev->l_next) 2553 ; 2554 2555 /* Link in the new entry. */ 2556 l->l_prev = prev; 2557 l->l_next = prev->l_next; 2558 if (l->l_next != NULL) 2559 l->l_next->l_prev = l; 2560 prev->l_next = l; 2561} 2562 2563static void 2564linkmap_delete(Obj_Entry *obj) 2565{ 2566 struct link_map *l = &obj->linkmap; 2567 2568 if (l->l_prev == NULL) { 2569 if ((r_debug.r_map = l->l_next) != NULL) 2570 l->l_next->l_prev = NULL; 2571 return; 2572 } 2573 2574 if ((l->l_prev->l_next = l->l_next) != NULL) 2575 l->l_next->l_prev = l->l_prev; 2576} 2577 2578/* 2579 * Function for the debugger to set a breakpoint on to gain control. 2580 * 2581 * The two parameters allow the debugger to easily find and determine 2582 * what the runtime loader is doing and to whom it is doing it. 2583 * 2584 * When the loadhook trap is hit (r_debug_state, set at program 2585 * initialization), the arguments can be found on the stack: 2586 * 2587 * +8 struct link_map *m 2588 * +4 struct r_debug *rd 2589 * +0 RetAddr 2590 */ 2591void 2592r_debug_state(struct r_debug* rd, struct link_map *m) 2593{ 2594} 2595 2596/* 2597 * Get address of the pointer variable in the main program. 2598 */ 2599static const void ** 2600get_program_var_addr(const char *name) 2601{ 2602 const Obj_Entry *obj; 2603 unsigned long hash; 2604 2605 hash = elf_hash(name); 2606 for (obj = obj_main; obj != NULL; obj = obj->next) { 2607 const Elf_Sym *def; 2608 2609 if ((def = symlook_obj(name, hash, obj, NULL, 0)) != NULL) { 2610 const void **addr; 2611 2612 addr = (const void **)(obj->relocbase + def->st_value); 2613 return addr; 2614 } 2615 } 2616 return NULL; 2617} 2618 2619/* 2620 * Set a pointer variable in the main program to the given value. This 2621 * is used to set key variables such as "environ" before any of the 2622 * init functions are called. 2623 */ 2624static void 2625set_program_var(const char *name, const void *value) 2626{ 2627 const void **addr; 2628 2629 if ((addr = get_program_var_addr(name)) != NULL) { 2630 dbg("\"%s\": *%p <-- %p", name, addr, value); 2631 *addr = value; 2632 } 2633} 2634 2635/* 2636 * Given a symbol name in a referencing object, find the corresponding 2637 * definition of the symbol. Returns a pointer to the symbol, or NULL if 2638 * no definition was found. Returns a pointer to the Obj_Entry of the 2639 * defining object via the reference parameter DEFOBJ_OUT. 2640 */ 2641static const Elf_Sym * 2642symlook_default(const char *name, unsigned long hash, const Obj_Entry *refobj, 2643 const Obj_Entry **defobj_out, const Ver_Entry *ventry, int flags) 2644{ 2645 DoneList donelist; 2646 const Elf_Sym *def; 2647 const Elf_Sym *symp; 2648 const Obj_Entry *obj; 2649 const Obj_Entry *defobj; 2650 const Objlist_Entry *elm; 2651 def = NULL; 2652 defobj = NULL; 2653 donelist_init(&donelist); 2654 2655 /* Look first in the referencing object if linked symbolically. */ 2656 if (refobj->symbolic && !donelist_check(&donelist, refobj)) { 2657 symp = symlook_obj(name, hash, refobj, ventry, flags); 2658 if (symp != NULL) { 2659 def = symp; 2660 defobj = refobj; 2661 } 2662 } 2663 2664 /* Search all objects loaded at program start up. */ 2665 if (def == NULL || ELF_ST_BIND(def->st_info) == STB_WEAK) { 2666 symp = symlook_list(name, hash, &list_main, &obj, ventry, flags, 2667 &donelist); 2668 if (symp != NULL && 2669 (def == NULL || ELF_ST_BIND(symp->st_info) != STB_WEAK)) { 2670 def = symp; 2671 defobj = obj; 2672 } 2673 } 2674 2675 /* Search all DAGs whose roots are RTLD_GLOBAL objects. */ 2676 STAILQ_FOREACH(elm, &list_global, link) { 2677 if (def != NULL && ELF_ST_BIND(def->st_info) != STB_WEAK) 2678 break; 2679 symp = symlook_list(name, hash, &elm->obj->dagmembers, &obj, ventry, 2680 flags, &donelist); 2681 if (symp != NULL && 2682 (def == NULL || ELF_ST_BIND(symp->st_info) != STB_WEAK)) { 2683 def = symp; 2684 defobj = obj; 2685 } 2686 } 2687 2688 /* Search all dlopened DAGs containing the referencing object. */ 2689 STAILQ_FOREACH(elm, &refobj->dldags, link) { 2690 if (def != NULL && ELF_ST_BIND(def->st_info) != STB_WEAK) 2691 break; 2692 symp = symlook_list(name, hash, &elm->obj->dagmembers, &obj, ventry, 2693 flags, &donelist); 2694 if (symp != NULL && 2695 (def == NULL || ELF_ST_BIND(symp->st_info) != STB_WEAK)) { 2696 def = symp; 2697 defobj = obj; 2698 } 2699 } 2700 2701 /* 2702 * Search the dynamic linker itself, and possibly resolve the 2703 * symbol from there. This is how the application links to 2704 * dynamic linker services such as dlopen. 2705 */ 2706 if (def == NULL || ELF_ST_BIND(def->st_info) == STB_WEAK) { 2707 symp = symlook_obj(name, hash, &obj_rtld, ventry, flags); 2708 if (symp != NULL) { 2709 def = symp; 2710 defobj = &obj_rtld; 2711 } 2712 } 2713 2714 if (def != NULL) 2715 *defobj_out = defobj; 2716 return def; 2717} 2718 2719static const Elf_Sym * 2720symlook_list(const char *name, unsigned long hash, const Objlist *objlist, 2721 const Obj_Entry **defobj_out, const Ver_Entry *ventry, int flags, 2722 DoneList *dlp) 2723{ 2724 const Elf_Sym *symp; 2725 const Elf_Sym *def; 2726 const Obj_Entry *defobj; 2727 const Objlist_Entry *elm; 2728 2729 def = NULL; 2730 defobj = NULL; 2731 STAILQ_FOREACH(elm, objlist, link) { 2732 if (donelist_check(dlp, elm->obj)) 2733 continue; 2734 if ((symp = symlook_obj(name, hash, elm->obj, ventry, flags)) != NULL) { 2735 if (def == NULL || ELF_ST_BIND(symp->st_info) != STB_WEAK) { 2736 def = symp; 2737 defobj = elm->obj; 2738 if (ELF_ST_BIND(def->st_info) != STB_WEAK) 2739 break; 2740 } 2741 } 2742 } 2743 if (def != NULL) 2744 *defobj_out = defobj; 2745 return def; 2746} 2747 2748/* 2749 * Search the symbol table of a shared object and all objects needed 2750 * by it for a symbol of the given name. Search order is 2751 * breadth-first. Returns a pointer to the symbol, or NULL if no 2752 * definition was found. 2753 */ 2754static const Elf_Sym * 2755symlook_needed(const char *name, unsigned long hash, const Needed_Entry *needed, 2756 const Obj_Entry **defobj_out, const Ver_Entry *ventry, int flags, 2757 DoneList *dlp) 2758{ 2759 const Elf_Sym *def, *def_w; 2760 const Needed_Entry *n; 2761 const Obj_Entry *obj, *defobj, *defobj1; 2762 2763 def = def_w = NULL; 2764 defobj = NULL; 2765 for (n = needed; n != NULL; n = n->next) { 2766 if ((obj = n->obj) == NULL || 2767 donelist_check(dlp, obj) || 2768 (def = symlook_obj(name, hash, obj, ventry, flags)) == NULL) 2769 continue; 2770 defobj = obj; 2771 if (ELF_ST_BIND(def->st_info) != STB_WEAK) { 2772 *defobj_out = defobj; 2773 return (def); 2774 } 2775 } 2776 /* 2777 * There we come when either symbol definition is not found in 2778 * directly needed objects, or found symbol is weak. 2779 */ 2780 for (n = needed; n != NULL; n = n->next) { 2781 if ((obj = n->obj) == NULL) 2782 continue; 2783 def_w = symlook_needed(name, hash, obj->needed, &defobj1, 2784 ventry, flags, dlp); 2785 if (def_w == NULL) 2786 continue; 2787 if (def == NULL || ELF_ST_BIND(def_w->st_info) != STB_WEAK) { 2788 def = def_w; 2789 defobj = defobj1; 2790 } 2791 if (ELF_ST_BIND(def_w->st_info) != STB_WEAK) 2792 break; 2793 } 2794 if (def != NULL) 2795 *defobj_out = defobj; 2796 return (def); 2797} 2798 2799/* 2800 * Search the symbol table of a single shared object for a symbol of 2801 * the given name and version, if requested. Returns a pointer to the 2802 * symbol, or NULL if no definition was found. 2803 * 2804 * The symbol's hash value is passed in for efficiency reasons; that 2805 * eliminates many recomputations of the hash value. 2806 */ 2807const Elf_Sym * 2808symlook_obj(const char *name, unsigned long hash, const Obj_Entry *obj, 2809 const Ver_Entry *ventry, int flags) 2810{ 2811 unsigned long symnum; 2812 const Elf_Sym *vsymp; 2813 Elf_Versym verndx; 2814 int vcount; 2815 2816 if (obj->buckets == NULL) 2817 return NULL; 2818 2819 vsymp = NULL; 2820 vcount = 0; 2821 symnum = obj->buckets[hash % obj->nbuckets]; 2822 2823 for (; symnum != STN_UNDEF; symnum = obj->chains[symnum]) { 2824 const Elf_Sym *symp; 2825 const char *strp; 2826 2827 if (symnum >= obj->nchains) 2828 return NULL; /* Bad object */ 2829 2830 symp = obj->symtab + symnum; 2831 strp = obj->strtab + symp->st_name; 2832 2833 switch (ELF_ST_TYPE(symp->st_info)) { 2834 case STT_FUNC: 2835 case STT_NOTYPE: 2836 case STT_OBJECT: 2837 if (symp->st_value == 0) 2838 continue; 2839 /* fallthrough */ 2840 case STT_TLS: 2841 if (symp->st_shndx != SHN_UNDEF) 2842 break; 2843#ifndef __mips__ 2844 else if (((flags & SYMLOOK_IN_PLT) == 0) && 2845 (ELF_ST_TYPE(symp->st_info) == STT_FUNC)) 2846 break; 2847 /* fallthrough */ 2848#endif 2849 default: 2850 continue; 2851 } 2852 if (name[0] != strp[0] || strcmp(name, strp) != 0) 2853 continue; 2854 2855 if (ventry == NULL) { 2856 if (obj->versyms != NULL) { 2857 verndx = VER_NDX(obj->versyms[symnum]); 2858 if (verndx > obj->vernum) { 2859 _rtld_error("%s: symbol %s references wrong version %d", 2860 obj->path, obj->strtab + symnum, verndx); 2861 continue; 2862 } 2863 /* 2864 * If we are not called from dlsym (i.e. this is a normal 2865 * relocation from unversioned binary, accept the symbol 2866 * immediately if it happens to have first version after 2867 * this shared object became versioned. Otherwise, if 2868 * symbol is versioned and not hidden, remember it. If it 2869 * is the only symbol with this name exported by the 2870 * shared object, it will be returned as a match at the 2871 * end of the function. If symbol is global (verndx < 2) 2872 * accept it unconditionally. 2873 */ 2874 if ((flags & SYMLOOK_DLSYM) == 0 && verndx == VER_NDX_GIVEN) 2875 return symp; 2876 else if (verndx >= VER_NDX_GIVEN) { 2877 if ((obj->versyms[symnum] & VER_NDX_HIDDEN) == 0) { 2878 if (vsymp == NULL) 2879 vsymp = symp; 2880 vcount ++; 2881 } 2882 continue; 2883 } 2884 } 2885 return symp; 2886 } else { 2887 if (obj->versyms == NULL) { 2888 if (object_match_name(obj, ventry->name)) { 2889 _rtld_error("%s: object %s should provide version %s for " 2890 "symbol %s", obj_rtld.path, obj->path, ventry->name, 2891 obj->strtab + symnum); 2892 continue; 2893 } 2894 } else { 2895 verndx = VER_NDX(obj->versyms[symnum]); 2896 if (verndx > obj->vernum) { 2897 _rtld_error("%s: symbol %s references wrong version %d", 2898 obj->path, obj->strtab + symnum, verndx); 2899 continue; 2900 } 2901 if (obj->vertab[verndx].hash != ventry->hash || 2902 strcmp(obj->vertab[verndx].name, ventry->name)) { 2903 /* 2904 * Version does not match. Look if this is a global symbol 2905 * and if it is not hidden. If global symbol (verndx < 2) 2906 * is available, use it. Do not return symbol if we are 2907 * called by dlvsym, because dlvsym looks for a specific 2908 * version and default one is not what dlvsym wants. 2909 */ 2910 if ((flags & SYMLOOK_DLSYM) || 2911 (obj->versyms[symnum] & VER_NDX_HIDDEN) || 2912 (verndx >= VER_NDX_GIVEN)) 2913 continue; 2914 } 2915 } 2916 return symp; 2917 } 2918 } 2919 return (vcount == 1) ? vsymp : NULL; 2920} 2921 2922static void 2923trace_loaded_objects(Obj_Entry *obj) 2924{ 2925 char *fmt1, *fmt2, *fmt, *main_local, *list_containers; 2926 int c; 2927 2928 if ((main_local = getenv(LD_ "TRACE_LOADED_OBJECTS_PROGNAME")) == NULL) 2929 main_local = ""; 2930 2931 if ((fmt1 = getenv(LD_ "TRACE_LOADED_OBJECTS_FMT1")) == NULL) 2932 fmt1 = "\t%o => %p (%x)\n"; 2933 2934 if ((fmt2 = getenv(LD_ "TRACE_LOADED_OBJECTS_FMT2")) == NULL) 2935 fmt2 = "\t%o (%x)\n"; 2936 2937 list_containers = getenv(LD_ "TRACE_LOADED_OBJECTS_ALL"); 2938 2939 for (; obj; obj = obj->next) { 2940 Needed_Entry *needed; 2941 char *name, *path; 2942 bool is_lib; 2943 2944 if (list_containers && obj->needed != NULL) 2945 printf("%s:\n", obj->path); 2946 for (needed = obj->needed; needed; needed = needed->next) { 2947 if (needed->obj != NULL) { 2948 if (needed->obj->traced && !list_containers) 2949 continue; 2950 needed->obj->traced = true; 2951 path = needed->obj->path; 2952 } else 2953 path = "not found"; 2954 2955 name = (char *)obj->strtab + needed->name; 2956 is_lib = strncmp(name, "lib", 3) == 0; /* XXX - bogus */ 2957 2958 fmt = is_lib ? fmt1 : fmt2; 2959 while ((c = *fmt++) != '\0') { 2960 switch (c) { 2961 default: 2962 putchar(c); 2963 continue; 2964 case '\\': 2965 switch (c = *fmt) { 2966 case '\0': 2967 continue; 2968 case 'n': 2969 putchar('\n'); 2970 break; 2971 case 't': 2972 putchar('\t'); 2973 break; 2974 } 2975 break; 2976 case '%': 2977 switch (c = *fmt) { 2978 case '\0': 2979 continue; 2980 case '%': 2981 default: 2982 putchar(c); 2983 break; 2984 case 'A': 2985 printf("%s", main_local); 2986 break; 2987 case 'a': 2988 printf("%s", obj_main->path); 2989 break; 2990 case 'o': 2991 printf("%s", name); 2992 break; 2993#if 0 2994 case 'm': 2995 printf("%d", sodp->sod_major); 2996 break; 2997 case 'n': 2998 printf("%d", sodp->sod_minor); 2999 break; 3000#endif 3001 case 'p': 3002 printf("%s", path); 3003 break; 3004 case 'x': 3005 printf("%p", needed->obj ? needed->obj->mapbase : 0); 3006 break; 3007 } 3008 break; 3009 } 3010 ++fmt; 3011 } 3012 } 3013 } 3014} 3015 3016/* 3017 * Unload a dlopened object and its dependencies from memory and from 3018 * our data structures. It is assumed that the DAG rooted in the 3019 * object has already been unreferenced, and that the object has a 3020 * reference count of 0. 3021 */ 3022static void 3023unload_object(Obj_Entry *root) 3024{ 3025 Obj_Entry *obj; 3026 Obj_Entry **linkp; 3027 3028 assert(root->refcount == 0); 3029 3030 /* 3031 * Pass over the DAG removing unreferenced objects from 3032 * appropriate lists. 3033 */ 3034 unlink_object(root); 3035 3036 /* Unmap all objects that are no longer referenced. */ 3037 linkp = &obj_list->next; 3038 while ((obj = *linkp) != NULL) { 3039 if (obj->refcount == 0) { 3040 LD_UTRACE(UTRACE_UNLOAD_OBJECT, obj, obj->mapbase, obj->mapsize, 0, 3041 obj->path); 3042 dbg("unloading \"%s\"", obj->path); 3043 munmap(obj->mapbase, obj->mapsize); 3044 linkmap_delete(obj); 3045 *linkp = obj->next; 3046 obj_count--; 3047 obj_free(obj); 3048 } else 3049 linkp = &obj->next; 3050 } 3051 obj_tail = linkp; 3052} 3053 3054static void 3055unlink_object(Obj_Entry *root) 3056{ 3057 Objlist_Entry *elm; 3058 3059 if (root->refcount == 0) { 3060 /* Remove the object from the RTLD_GLOBAL list. */ 3061 objlist_remove(&list_global, root); 3062 3063 /* Remove the object from all objects' DAG lists. */ 3064 STAILQ_FOREACH(elm, &root->dagmembers, link) { 3065 objlist_remove(&elm->obj->dldags, root); 3066 if (elm->obj != root) 3067 unlink_object(elm->obj); 3068 } 3069 } 3070} 3071 3072static void 3073ref_dag(Obj_Entry *root) 3074{ 3075 Objlist_Entry *elm; 3076 3077 STAILQ_FOREACH(elm, &root->dagmembers, link) 3078 elm->obj->refcount++; 3079} 3080 3081static void 3082unref_dag(Obj_Entry *root) 3083{ 3084 Objlist_Entry *elm; 3085 3086 STAILQ_FOREACH(elm, &root->dagmembers, link) 3087 elm->obj->refcount--; 3088} 3089 3090/* 3091 * Common code for MD __tls_get_addr(). 3092 */ 3093void * 3094tls_get_addr_common(Elf_Addr** dtvp, int index, size_t offset) 3095{ 3096 Elf_Addr* dtv = *dtvp; 3097 int lockstate; 3098 3099 /* Check dtv generation in case new modules have arrived */ 3100 if (dtv[0] != tls_dtv_generation) { 3101 Elf_Addr* newdtv; 3102 int to_copy; 3103 3104 lockstate = wlock_acquire(rtld_bind_lock); 3105 newdtv = calloc(1, (tls_max_index + 2) * sizeof(Elf_Addr)); 3106 to_copy = dtv[1]; 3107 if (to_copy > tls_max_index) 3108 to_copy = tls_max_index; 3109 memcpy(&newdtv[2], &dtv[2], to_copy * sizeof(Elf_Addr)); 3110 newdtv[0] = tls_dtv_generation; 3111 newdtv[1] = tls_max_index; 3112 free(dtv); 3113 wlock_release(rtld_bind_lock, lockstate); 3114 *dtvp = newdtv; 3115 } 3116 3117 /* Dynamically allocate module TLS if necessary */ 3118 if (!dtv[index + 1]) { 3119 /* Signal safe, wlock will block out signals. */ 3120 lockstate = wlock_acquire(rtld_bind_lock); 3121 if (!dtv[index + 1]) 3122 dtv[index + 1] = (Elf_Addr)allocate_module_tls(index); 3123 wlock_release(rtld_bind_lock, lockstate); 3124 } 3125 return (void*) (dtv[index + 1] + offset); 3126} 3127 3128/* XXX not sure what variants to use for arm. */ 3129 3130#if defined(__ia64__) || defined(__powerpc__) 3131 3132/* 3133 * Allocate Static TLS using the Variant I method. 3134 */ 3135void * 3136allocate_tls(Obj_Entry *objs, void *oldtcb, size_t tcbsize, size_t tcbalign) 3137{ 3138 Obj_Entry *obj; 3139 char *tcb; 3140 Elf_Addr **tls; 3141 Elf_Addr *dtv; 3142 Elf_Addr addr; 3143 int i; 3144 3145 if (oldtcb != NULL && tcbsize == TLS_TCB_SIZE) 3146 return (oldtcb); 3147 3148 assert(tcbsize >= TLS_TCB_SIZE); 3149 tcb = calloc(1, tls_static_space - TLS_TCB_SIZE + tcbsize); 3150 tls = (Elf_Addr **)(tcb + tcbsize - TLS_TCB_SIZE); 3151 3152 if (oldtcb != NULL) { 3153 memcpy(tls, oldtcb, tls_static_space); 3154 free(oldtcb); 3155 3156 /* Adjust the DTV. */ 3157 dtv = tls[0]; 3158 for (i = 0; i < dtv[1]; i++) { 3159 if (dtv[i+2] >= (Elf_Addr)oldtcb && 3160 dtv[i+2] < (Elf_Addr)oldtcb + tls_static_space) { 3161 dtv[i+2] = dtv[i+2] - (Elf_Addr)oldtcb + (Elf_Addr)tls; 3162 } 3163 } 3164 } else { 3165 dtv = calloc(tls_max_index + 2, sizeof(Elf_Addr)); 3166 tls[0] = dtv; 3167 dtv[0] = tls_dtv_generation; 3168 dtv[1] = tls_max_index; 3169 3170 for (obj = objs; obj; obj = obj->next) { 3171 if (obj->tlsoffset > 0) { 3172 addr = (Elf_Addr)tls + obj->tlsoffset; 3173 if (obj->tlsinitsize > 0) 3174 memcpy((void*) addr, obj->tlsinit, obj->tlsinitsize); 3175 if (obj->tlssize > obj->tlsinitsize) 3176 memset((void*) (addr + obj->tlsinitsize), 0, 3177 obj->tlssize - obj->tlsinitsize); 3178 dtv[obj->tlsindex + 1] = addr; 3179 } 3180 } 3181 } 3182 3183 return (tcb); 3184} 3185 3186void 3187free_tls(void *tcb, size_t tcbsize, size_t tcbalign) 3188{ 3189 Elf_Addr *dtv; 3190 Elf_Addr tlsstart, tlsend; 3191 int dtvsize, i; 3192 3193 assert(tcbsize >= TLS_TCB_SIZE); 3194 3195 tlsstart = (Elf_Addr)tcb + tcbsize - TLS_TCB_SIZE; 3196 tlsend = tlsstart + tls_static_space; 3197 3198 dtv = *(Elf_Addr **)tlsstart; 3199 dtvsize = dtv[1]; 3200 for (i = 0; i < dtvsize; i++) { 3201 if (dtv[i+2] && (dtv[i+2] < tlsstart || dtv[i+2] >= tlsend)) { 3202 free((void*)dtv[i+2]); 3203 } 3204 } 3205 free(dtv); 3206 free(tcb); 3207} 3208 3209#endif 3210 3211#if defined(__i386__) || defined(__amd64__) || defined(__sparc64__) || \ 3212 defined(__arm__) || defined(__mips__) 3213 3214/* 3215 * Allocate Static TLS using the Variant II method. 3216 */ 3217void * 3218allocate_tls(Obj_Entry *objs, void *oldtls, size_t tcbsize, size_t tcbalign) 3219{ 3220 Obj_Entry *obj; 3221 size_t size; 3222 char *tls; 3223 Elf_Addr *dtv, *olddtv; 3224 Elf_Addr segbase, oldsegbase, addr; 3225 int i; 3226 3227 size = round(tls_static_space, tcbalign); 3228 3229 assert(tcbsize >= 2*sizeof(Elf_Addr)); 3230 tls = calloc(1, size + tcbsize); 3231 dtv = calloc(1, (tls_max_index + 2) * sizeof(Elf_Addr)); 3232 3233 segbase = (Elf_Addr)(tls + size); 3234 ((Elf_Addr*)segbase)[0] = segbase; 3235 ((Elf_Addr*)segbase)[1] = (Elf_Addr) dtv; 3236 3237 dtv[0] = tls_dtv_generation; 3238 dtv[1] = tls_max_index; 3239 3240 if (oldtls) { 3241 /* 3242 * Copy the static TLS block over whole. 3243 */ 3244 oldsegbase = (Elf_Addr) oldtls; 3245 memcpy((void *)(segbase - tls_static_space), 3246 (const void *)(oldsegbase - tls_static_space), 3247 tls_static_space); 3248 3249 /* 3250 * If any dynamic TLS blocks have been created tls_get_addr(), 3251 * move them over. 3252 */ 3253 olddtv = ((Elf_Addr**)oldsegbase)[1]; 3254 for (i = 0; i < olddtv[1]; i++) { 3255 if (olddtv[i+2] < oldsegbase - size || olddtv[i+2] > oldsegbase) { 3256 dtv[i+2] = olddtv[i+2]; 3257 olddtv[i+2] = 0; 3258 } 3259 } 3260 3261 /* 3262 * We assume that this block was the one we created with 3263 * allocate_initial_tls(). 3264 */ 3265 free_tls(oldtls, 2*sizeof(Elf_Addr), sizeof(Elf_Addr)); 3266 } else { 3267 for (obj = objs; obj; obj = obj->next) { 3268 if (obj->tlsoffset) { 3269 addr = segbase - obj->tlsoffset; 3270 memset((void*) (addr + obj->tlsinitsize), 3271 0, obj->tlssize - obj->tlsinitsize); 3272 if (obj->tlsinit) 3273 memcpy((void*) addr, obj->tlsinit, obj->tlsinitsize); 3274 dtv[obj->tlsindex + 1] = addr; 3275 } 3276 } 3277 } 3278 3279 return (void*) segbase; 3280} 3281 3282void 3283free_tls(void *tls, size_t tcbsize, size_t tcbalign) 3284{ 3285 size_t size; 3286 Elf_Addr* dtv; 3287 int dtvsize, i; 3288 Elf_Addr tlsstart, tlsend; 3289 3290 /* 3291 * Figure out the size of the initial TLS block so that we can 3292 * find stuff which ___tls_get_addr() allocated dynamically. 3293 */ 3294 size = round(tls_static_space, tcbalign); 3295 3296 dtv = ((Elf_Addr**)tls)[1]; 3297 dtvsize = dtv[1]; 3298 tlsend = (Elf_Addr) tls; 3299 tlsstart = tlsend - size; 3300 for (i = 0; i < dtvsize; i++) { 3301 if (dtv[i+2] && (dtv[i+2] < tlsstart || dtv[i+2] > tlsend)) { 3302 free((void*) dtv[i+2]); 3303 } 3304 } 3305 3306 free((void*) tlsstart); 3307 free((void*) dtv); 3308} 3309 3310#endif 3311 3312/* 3313 * Allocate TLS block for module with given index. 3314 */ 3315void * 3316allocate_module_tls(int index) 3317{ 3318 Obj_Entry* obj; 3319 char* p; 3320 3321 for (obj = obj_list; obj; obj = obj->next) { 3322 if (obj->tlsindex == index) 3323 break; 3324 } 3325 if (!obj) { 3326 _rtld_error("Can't find module with TLS index %d", index); 3327 die(); 3328 } 3329 3330 p = malloc(obj->tlssize); 3331 if (p == NULL) { 3332 _rtld_error("Cannot allocate TLS block for index %d", index); 3333 die(); 3334 } 3335 memcpy(p, obj->tlsinit, obj->tlsinitsize); 3336 memset(p + obj->tlsinitsize, 0, obj->tlssize - obj->tlsinitsize); 3337 3338 return p; 3339} 3340 3341bool 3342allocate_tls_offset(Obj_Entry *obj) 3343{ 3344 size_t off; 3345 3346 if (obj->tls_done) 3347 return true; 3348 3349 if (obj->tlssize == 0) { 3350 obj->tls_done = true; 3351 return true; 3352 } 3353 3354 if (obj->tlsindex == 1) 3355 off = calculate_first_tls_offset(obj->tlssize, obj->tlsalign); 3356 else 3357 off = calculate_tls_offset(tls_last_offset, tls_last_size, 3358 obj->tlssize, obj->tlsalign); 3359 3360 /* 3361 * If we have already fixed the size of the static TLS block, we 3362 * must stay within that size. When allocating the static TLS, we 3363 * leave a small amount of space spare to be used for dynamically 3364 * loading modules which use static TLS. 3365 */ 3366 if (tls_static_space) { 3367 if (calculate_tls_end(off, obj->tlssize) > tls_static_space) 3368 return false; 3369 } 3370 3371 tls_last_offset = obj->tlsoffset = off; 3372 tls_last_size = obj->tlssize; 3373 obj->tls_done = true; 3374 3375 return true; 3376} 3377 3378void 3379free_tls_offset(Obj_Entry *obj) 3380{ 3381 3382 /* 3383 * If we were the last thing to allocate out of the static TLS 3384 * block, we give our space back to the 'allocator'. This is a 3385 * simplistic workaround to allow libGL.so.1 to be loaded and 3386 * unloaded multiple times. 3387 */ 3388 if (calculate_tls_end(obj->tlsoffset, obj->tlssize) 3389 == calculate_tls_end(tls_last_offset, tls_last_size)) { 3390 tls_last_offset -= obj->tlssize; 3391 tls_last_size = 0; 3392 } 3393} 3394 3395void * 3396_rtld_allocate_tls(void *oldtls, size_t tcbsize, size_t tcbalign) 3397{ 3398 void *ret; 3399 int lockstate; 3400 3401 lockstate = wlock_acquire(rtld_bind_lock); 3402 ret = allocate_tls(obj_list, oldtls, tcbsize, tcbalign); 3403 wlock_release(rtld_bind_lock, lockstate); 3404 return (ret); 3405} 3406 3407void 3408_rtld_free_tls(void *tcb, size_t tcbsize, size_t tcbalign) 3409{ 3410 int lockstate; 3411 3412 lockstate = wlock_acquire(rtld_bind_lock); 3413 free_tls(tcb, tcbsize, tcbalign); 3414 wlock_release(rtld_bind_lock, lockstate); 3415} 3416 3417static void 3418object_add_name(Obj_Entry *obj, const char *name) 3419{ 3420 Name_Entry *entry; 3421 size_t len; 3422 3423 len = strlen(name); 3424 entry = malloc(sizeof(Name_Entry) + len); 3425 3426 if (entry != NULL) { 3427 strcpy(entry->name, name); 3428 STAILQ_INSERT_TAIL(&obj->names, entry, link); 3429 } 3430} 3431 3432static int 3433object_match_name(const Obj_Entry *obj, const char *name) 3434{ 3435 Name_Entry *entry; 3436 3437 STAILQ_FOREACH(entry, &obj->names, link) { 3438 if (strcmp(name, entry->name) == 0) 3439 return (1); 3440 } 3441 return (0); 3442} 3443 3444static Obj_Entry * 3445locate_dependency(const Obj_Entry *obj, const char *name) 3446{ 3447 const Objlist_Entry *entry; 3448 const Needed_Entry *needed; 3449 3450 STAILQ_FOREACH(entry, &list_main, link) { 3451 if (object_match_name(entry->obj, name)) 3452 return entry->obj; 3453 } 3454 3455 for (needed = obj->needed; needed != NULL; needed = needed->next) { 3456 if (needed->obj == NULL) 3457 continue; 3458 if (object_match_name(needed->obj, name)) 3459 return needed->obj; 3460 } 3461 _rtld_error("%s: Unexpected inconsistency: dependency %s not found", 3462 obj->path, name); 3463 die(); 3464} 3465 3466static int 3467check_object_provided_version(Obj_Entry *refobj, const Obj_Entry *depobj, 3468 const Elf_Vernaux *vna) 3469{ 3470 const Elf_Verdef *vd; 3471 const char *vername; 3472 3473 vername = refobj->strtab + vna->vna_name; 3474 vd = depobj->verdef; 3475 if (vd == NULL) { 3476 _rtld_error("%s: version %s required by %s not defined", 3477 depobj->path, vername, refobj->path); 3478 return (-1); 3479 } 3480 for (;;) { 3481 if (vd->vd_version != VER_DEF_CURRENT) { 3482 _rtld_error("%s: Unsupported version %d of Elf_Verdef entry", 3483 depobj->path, vd->vd_version); 3484 return (-1); 3485 } 3486 if (vna->vna_hash == vd->vd_hash) { 3487 const Elf_Verdaux *aux = (const Elf_Verdaux *) 3488 ((char *)vd + vd->vd_aux); 3489 if (strcmp(vername, depobj->strtab + aux->vda_name) == 0) 3490 return (0); 3491 } 3492 if (vd->vd_next == 0) 3493 break; 3494 vd = (const Elf_Verdef *) ((char *)vd + vd->vd_next); 3495 } 3496 if (vna->vna_flags & VER_FLG_WEAK) 3497 return (0); 3498 _rtld_error("%s: version %s required by %s not found", 3499 depobj->path, vername, refobj->path); 3500 return (-1); 3501} 3502 3503static int 3504rtld_verify_object_versions(Obj_Entry *obj) 3505{ 3506 const Elf_Verneed *vn; 3507 const Elf_Verdef *vd; 3508 const Elf_Verdaux *vda; 3509 const Elf_Vernaux *vna; 3510 const Obj_Entry *depobj; 3511 int maxvernum, vernum; 3512 3513 maxvernum = 0; 3514 /* 3515 * Walk over defined and required version records and figure out 3516 * max index used by any of them. Do very basic sanity checking 3517 * while there. 3518 */ 3519 vn = obj->verneed; 3520 while (vn != NULL) { 3521 if (vn->vn_version != VER_NEED_CURRENT) { 3522 _rtld_error("%s: Unsupported version %d of Elf_Verneed entry", 3523 obj->path, vn->vn_version); 3524 return (-1); 3525 } 3526 vna = (const Elf_Vernaux *) ((char *)vn + vn->vn_aux); 3527 for (;;) { 3528 vernum = VER_NEED_IDX(vna->vna_other); 3529 if (vernum > maxvernum) 3530 maxvernum = vernum; 3531 if (vna->vna_next == 0) 3532 break; 3533 vna = (const Elf_Vernaux *) ((char *)vna + vna->vna_next); 3534 } 3535 if (vn->vn_next == 0) 3536 break; 3537 vn = (const Elf_Verneed *) ((char *)vn + vn->vn_next); 3538 } 3539 3540 vd = obj->verdef; 3541 while (vd != NULL) { 3542 if (vd->vd_version != VER_DEF_CURRENT) { 3543 _rtld_error("%s: Unsupported version %d of Elf_Verdef entry", 3544 obj->path, vd->vd_version); 3545 return (-1); 3546 } 3547 vernum = VER_DEF_IDX(vd->vd_ndx); 3548 if (vernum > maxvernum) 3549 maxvernum = vernum; 3550 if (vd->vd_next == 0) 3551 break; 3552 vd = (const Elf_Verdef *) ((char *)vd + vd->vd_next); 3553 } 3554 3555 if (maxvernum == 0) 3556 return (0); 3557 3558 /* 3559 * Store version information in array indexable by version index. 3560 * Verify that object version requirements are satisfied along the 3561 * way. 3562 */ 3563 obj->vernum = maxvernum + 1; 3564 obj->vertab = calloc(obj->vernum, sizeof(Ver_Entry)); 3565 3566 vd = obj->verdef; 3567 while (vd != NULL) { 3568 if ((vd->vd_flags & VER_FLG_BASE) == 0) { 3569 vernum = VER_DEF_IDX(vd->vd_ndx); 3570 assert(vernum <= maxvernum); 3571 vda = (const Elf_Verdaux *)((char *)vd + vd->vd_aux); 3572 obj->vertab[vernum].hash = vd->vd_hash; 3573 obj->vertab[vernum].name = obj->strtab + vda->vda_name; 3574 obj->vertab[vernum].file = NULL; 3575 obj->vertab[vernum].flags = 0; 3576 } 3577 if (vd->vd_next == 0) 3578 break; 3579 vd = (const Elf_Verdef *) ((char *)vd + vd->vd_next); 3580 } 3581 3582 vn = obj->verneed; 3583 while (vn != NULL) { 3584 depobj = locate_dependency(obj, obj->strtab + vn->vn_file); 3585 vna = (const Elf_Vernaux *) ((char *)vn + vn->vn_aux); 3586 for (;;) { 3587 if (check_object_provided_version(obj, depobj, vna)) 3588 return (-1); 3589 vernum = VER_NEED_IDX(vna->vna_other); 3590 assert(vernum <= maxvernum); 3591 obj->vertab[vernum].hash = vna->vna_hash; 3592 obj->vertab[vernum].name = obj->strtab + vna->vna_name; 3593 obj->vertab[vernum].file = obj->strtab + vn->vn_file; 3594 obj->vertab[vernum].flags = (vna->vna_other & VER_NEED_HIDDEN) ? 3595 VER_INFO_HIDDEN : 0; 3596 if (vna->vna_next == 0) 3597 break; 3598 vna = (const Elf_Vernaux *) ((char *)vna + vna->vna_next); 3599 } 3600 if (vn->vn_next == 0) 3601 break; 3602 vn = (const Elf_Verneed *) ((char *)vn + vn->vn_next); 3603 } 3604 return 0; 3605} 3606 3607static int 3608rtld_verify_versions(const Objlist *objlist) 3609{ 3610 Objlist_Entry *entry; 3611 int rc; 3612 3613 rc = 0; 3614 STAILQ_FOREACH(entry, objlist, link) { 3615 /* 3616 * Skip dummy objects or objects that have their version requirements 3617 * already checked. 3618 */ 3619 if (entry->obj->strtab == NULL || entry->obj->vertab != NULL) 3620 continue; 3621 if (rtld_verify_object_versions(entry->obj) == -1) { 3622 rc = -1; 3623 if (ld_tracing == NULL) 3624 break; 3625 } 3626 } 3627 if (rc == 0 || ld_tracing != NULL) 3628 rc = rtld_verify_object_versions(&obj_rtld); 3629 return rc; 3630} 3631 3632const Ver_Entry * 3633fetch_ventry(const Obj_Entry *obj, unsigned long symnum) 3634{ 3635 Elf_Versym vernum; 3636 3637 if (obj->vertab) { 3638 vernum = VER_NDX(obj->versyms[symnum]); 3639 if (vernum >= obj->vernum) { 3640 _rtld_error("%s: symbol %s has wrong verneed value %d", 3641 obj->path, obj->strtab + symnum, vernum); 3642 } else if (obj->vertab[vernum].hash != 0) { 3643 return &obj->vertab[vernum]; 3644 } 3645 } 3646 return NULL; 3647} 3648 3649/* 3650 * Overrides for libc_pic-provided functions. 3651 */ 3652 3653int 3654__getosreldate(void) 3655{ 3656 size_t len; 3657 int oid[2]; 3658 int error, osrel; 3659 3660 if (osreldate != 0) 3661 return (osreldate); 3662 3663 oid[0] = CTL_KERN; 3664 oid[1] = KERN_OSRELDATE; 3665 osrel = 0; 3666 len = sizeof(osrel); 3667 error = sysctl(oid, 2, &osrel, &len, NULL, 0); 3668 if (error == 0 && osrel > 0 && len == sizeof(osrel)) 3669 osreldate = osrel; 3670 return (osreldate); 3671} 3672 3673/* 3674 * No unresolved symbols for rtld. 3675 */ 3676void 3677__pthread_cxa_finalize(struct dl_phdr_info *a) 3678{ 3679} 3680