/* $NetBSD: rtld.c,v 1.45 2001/05/10 20:19:25 christos Exp $ */ /* * Copyright 1996 John D. Polstra. * Copyright 1996 Matt Thomas * All rights reserved. * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions * are met: * 1. Redistributions of source code must retain the above copyright * notice, this list of conditions and the following disclaimer. * 2. Redistributions in binary form must reproduce the above copyright * notice, this list of conditions and the following disclaimer in the * documentation and/or other materials provided with the distribution. * 3. All advertising materials mentioning features or use of this software * must display the following acknowledgement: * This product includes software developed by John Polstra. * 4. The name of the author may not be used to endorse or promote products * derived from this software without specific prior written permission. * * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. */ /* * Dynamic linker for ELF. * * John Polstra . */ #include #include #include #include #include #include #include #include #include #include #include #include #include #include "debug.h" #include "rtld.h" #if !defined(lint) #include "sysident.h" #endif #define END_SYM "_end" /* * Debugging support. */ typedef void (*funcptr) __P((void)); /* * Function declarations. */ static void _rtld_init __P((caddr_t, int)); static void _rtld_exit __P((void)); Elf_Addr _rtld __P((Elf_Addr *)); /* * Data declarations. */ static char *error_message; /* Message for dlopen(), or NULL */ struct r_debug _rtld_debug; /* for GDB; */ bool _rtld_trust; /* False for setuid and setgid programs */ Obj_Entry *_rtld_objlist; /* Head of linked list of shared objects */ Obj_Entry **_rtld_objtail; /* Link field of last object in list */ Obj_Entry *_rtld_objmain; /* The main program shared object */ Obj_Entry _rtld_objself; /* The dynamic linker shared object */ char _rtld_path[] = _PATH_RTLD; unsigned long _rtld_curmark; /* Current mark value */ Elf_Sym _rtld_sym_zero; /* For resolving undefined weak refs. */ #ifdef VARPSZ int _rtld_pagesz; /* Page size, as provided by kernel */ #endif Objlist _rtld_list_main = /* Objects loaded at program startup */ SIMPLEQ_HEAD_INITIALIZER(_rtld_list_main); Search_Path *_rtld_default_paths; Search_Path *_rtld_paths; Library_Xform *_rtld_xforms; /* * Global declarations normally provided by crt0. */ char *__progname; char **environ; #ifdef OLD_GOT extern Elf_Addr _GLOBAL_OFFSET_TABLE_[]; #else extern Elf_Addr _GLOBAL_OFFSET_TABLE_[]; extern Elf_Dyn _DYNAMIC; #endif static void _rtld_call_fini_functions __P((Obj_Entry *)); static void _rtld_call_init_functions __P((Obj_Entry *)); static Obj_Entry *_rtld_dlcheck __P((void *)); static void _rtld_init_dag __P((Obj_Entry *)); static void _rtld_init_dag1 __P((Obj_Entry *, Obj_Entry *)); static void _rtld_objlist_remove __P((Objlist *, Obj_Entry *)); static void _rtld_unload_object __P((Obj_Entry *, bool)); static void _rtld_unref_dag __P((Obj_Entry *)); static Obj_Entry *_rtld_obj_from_addr __P((const void *)); static void _rtld_call_fini_functions(first) Obj_Entry *first; { Obj_Entry *obj; for (obj = first; obj != NULL; obj = obj->next) if (obj->fini != NULL) (*obj->fini)(); } static void _rtld_call_init_functions(first) Obj_Entry *first; { if (first != NULL) { _rtld_call_init_functions(first->next); if (first->init != NULL) (*first->init)(); } } /* * Initialize the dynamic linker. The argument is the address at which * the dynamic linker has been mapped into memory. The primary task of * this function is to relocate the dynamic linker. */ static void _rtld_init(mapbase, pagesz) caddr_t mapbase; int pagesz; { Obj_Entry objself;/* The dynamic linker shared object */ const Elf_Ehdr *hdr = (Elf_Ehdr *) mapbase; #ifdef RTLD_RELOCATE_SELF int dodebug = false; #else int dodebug = true; #endif int i; memset(&objself, 0, sizeof objself); /* Conjure up an Obj_Entry structure for the dynamic linker. */ objself.path = NULL; objself.rtld = true; objself.mapbase = mapbase; objself.phdr = (Elf_Phdr *) (mapbase + hdr->e_phoff); for (i = 0; i < hdr->e_phnum; i++) { if (objself.phdr[i].p_type == PT_LOAD) { #ifdef VARPSZ /* We can't touch _rtld_pagesz yet so we can't use round_*() */ #define _rnd_down(x) ((x) & ~((long)pagesz-1)) #define _rnd_up(x) _rnd_down((x) + pagesz - 1) objself.textsize = _rnd_up(objself.phdr[i].p_vaddr + objself.phdr[i].p_memsz) - _rnd_down(objself.phdr[i].p_vaddr); #undef _rnd_down(x) #undef _rnd_up(x) #else objself.textsize = round_up(objself.phdr[i].p_vaddr + objself.phdr[i].p_memsz) - round_down(objself.phdr[i].p_vaddr); #endif break; } } #if defined(__mips__) /* * mips and ld.so currently linked at load address, * so no relocation needed */ objself.relocbase = 0; #else objself.relocbase = mapbase; #endif objself.pltgot = NULL; #ifdef OLD_GOT objself.dynamic = (Elf_Dyn *) _GLOBAL_OFFSET_TABLE_[0]; #else objself.dynamic = (Elf_Dyn *) & _DYNAMIC; #endif #ifdef RTLD_RELOCATE_SELF /* We have not been relocated yet, so fix the dynamic address */ objself.dynamic = (Elf_Dyn *) ((u_long) mapbase + (char *) objself.dynamic); #endif /* RTLD_RELOCATE_SELF */ _rtld_digest_dynamic(&objself); #ifdef __alpha__ /* XXX XXX XXX */ objself.pltgot = NULL; #endif assert(objself.needed == NULL); #if !defined(__mips__) && !defined(__i386__) && !defined(__vax__) /* no relocation for mips/i386 */ assert(!objself.textrel); #endif _rtld_relocate_objects(&objself, true, dodebug); /* * Now that we relocated ourselves, we can use globals. */ _rtld_objself = objself; _rtld_objself.path = _rtld_path; _rtld_add_paths(&_rtld_default_paths, RTLD_DEFAULT_LIBRARY_PATH, true); /* * Set up the _rtld_objlist pointer, so that rtld symbols can be found. */ _rtld_objlist = &_rtld_objself; /* Make the object list empty again. */ _rtld_objlist = NULL; _rtld_objtail = &_rtld_objlist; _rtld_debug.r_brk = _rtld_debug_state; _rtld_debug.r_state = RT_CONSISTENT; } /* * Cleanup procedure. It will be called (by the atexit() mechanism) just * before the process exits. */ static void _rtld_exit() { dbg(("rtld_exit()")); _rtld_call_fini_functions(_rtld_objlist->next); } /* * Main entry point for dynamic linking. The argument is the stack * pointer. The stack is expected to be laid out as described in the * SVR4 ABI specification, Intel 386 Processor Supplement. Specifically, * the stack pointer points to a word containing ARGC. Following that * in the stack is a null-terminated sequence of pointers to argument * strings. Then comes a null-terminated sequence of pointers to * environment strings. Finally, there is a sequence of "auxiliary * vector" entries. * * This function returns the entry point for the main program, the dynamic * linker's exit procedure in sp[0], and a pointer to the main object in * sp[1]. */ Elf_Addr _rtld(sp) Elf_Addr *sp; { const AuxInfo *pAUX_base, *pAUX_entry, *pAUX_execfd, *pAUX_phdr, *pAUX_phent, *pAUX_phnum; #ifdef VARPSZ const AuxInfo *pAUX_pagesz; #endif char **env; const AuxInfo *aux; const AuxInfo *auxp; Elf_Addr *const osp = sp; bool bind_now = 0; const char *ld_bind_now; const char **argv; long argc; Obj_Entry *obj; const char **real___progname; const Obj_Entry **real___mainprog_obj; char ***real_environ; #if defined(RTLD_DEBUG) && !defined(RTLD_RELOCATE_SELF) int i = 0; #endif /* * On entry, the dynamic linker itself has not been relocated yet. * Be very careful not to reference any global data until after * _rtld_init has returned. It is OK to reference file-scope statics * and string constants, and to call static and global functions. */ /* Find the auxiliary vector on the stack. */ /* first Elf_Word reserved to address of exit routine */ #if defined(RTLD_DEBUG) && !defined(RTLD_RELOCATE_SELF) dbg(("sp = %p, argc = %ld, argv = %p <%s>\n", sp, (long)sp[2], &sp[3], (char *) sp[3])); dbg(("got is at %p, dynamic is at %p\n", _GLOBAL_OFFSET_TABLE_, &_DYNAMIC)); debug = 1; dbg(("_ctype_ is %p\n", _ctype_)); #endif sp += 2; /* skip over return argument space */ argv = (const char **) &sp[1]; argc = *(long *)sp; #ifdef __sparc_v9__ /* XXX Temporary hack for argc format conversion. */ argc = (argc >> 32) | (argc & 0xffffffff); #endif sp += 2 + argc; /* Skip over argc, arguments, and NULL * terminator */ env = (char **) sp; while (*sp++ != 0) { /* Skip over environment, and NULL terminator */ #if defined(RTLD_DEBUG) && !defined(RTLD_RELOCATE_SELF) dbg(("env[%d] = %p %s\n", i++, (void *)sp[-1], (char *)sp[-1])); #endif } aux = (const AuxInfo *) sp; pAUX_base = pAUX_entry = pAUX_execfd = NULL; pAUX_phdr = pAUX_phent = pAUX_phnum = NULL; #ifdef VARPSZ pAUX_pagesz = NULL; #endif /* * First pass through the the auxiliary vector, avoiding the use * of a `switch() {}' statement at this stage. A `switch()' may * be translated into code utilizing a jump table approach which * references the equivalent of a global variable. This must be * avoided until _rtld_init() has done its job. * * _rtld_init() only needs `pAUX_base' and possibly `pAUX_pagesz', * so we look for just those in this pass. */ for (auxp = aux; auxp->a_type != AT_NULL; ++auxp) { if (auxp->a_type == AT_BASE) pAUX_base = auxp; #ifdef VARPSZ if (auxp->a_type == AT_PAGESZ) pAUX_pagesz = auxp; #endif } /* Initialize and relocate ourselves. */ assert(pAUX_base != NULL); #ifdef VARPSZ assert(pAUX_pagesz != NULL); _rtld_init((caddr_t) pAUX_base->a_v, (int)pAUX_pagesz->a_v); #else _rtld_init((caddr_t) pAUX_base->a_v, 0); #endif /* Digest the auxiliary vector (full pass now that we can afford it). */ for (auxp = aux; auxp->a_type != AT_NULL; ++auxp) { switch (auxp->a_type) { case AT_BASE: pAUX_base = auxp; break; case AT_ENTRY: pAUX_entry = auxp; break; case AT_EXECFD: pAUX_execfd = auxp; break; case AT_PHDR: pAUX_phdr = auxp; break; case AT_PHENT: pAUX_phent = auxp; break; case AT_PHNUM: pAUX_phnum = auxp; break; #ifdef VARPSZ case AT_PAGESZ: pAUX_pagesz = auxp; break; #endif } } #ifdef VARPSZ _rtld_pagesz = (int)pAUX_pagesz->a_v; #endif #ifdef RTLD_DEBUG dbg(("_ctype_ is %p\n", _ctype_)); #endif __progname = _rtld_objself.path; environ = env; _rtld_trust = geteuid() == getuid() && getegid() == getgid(); ld_bind_now = getenv("LD_BIND_NOW"); if (ld_bind_now != NULL && *ld_bind_now != '\0') bind_now = true; if (_rtld_trust) { #ifdef DEBUG const char *ld_debug = getenv("LD_DEBUG"); if (ld_debug != NULL && *ld_debug != '\0') debug = 1; #endif _rtld_add_paths(&_rtld_paths, getenv("LD_LIBRARY_PATH"), true); } _rtld_process_hints(&_rtld_paths, &_rtld_xforms, _PATH_LD_HINTS, true); dbg(("%s is initialized, base address = %p", __progname, (void *) pAUX_base->a_v)); /* * Load the main program, or process its program header if it is * already loaded. */ if (pAUX_execfd != NULL) { /* Load the main program. */ int fd = pAUX_execfd->a_v; dbg(("loading main program")); _rtld_objmain = _rtld_map_object(argv[0], fd, NULL); close(fd); if (_rtld_objmain == NULL) _rtld_die(); } else { /* Main program already loaded. */ const Elf_Phdr *phdr; int phnum; caddr_t entry; dbg(("processing main program's program header")); assert(pAUX_phdr != NULL); phdr = (const Elf_Phdr *) pAUX_phdr->a_v; assert(pAUX_phnum != NULL); phnum = pAUX_phnum->a_v; assert(pAUX_phent != NULL); assert(pAUX_phent->a_v == sizeof(Elf_Phdr)); assert(pAUX_entry != NULL); entry = (caddr_t) pAUX_entry->a_v; _rtld_objmain = _rtld_digest_phdr(phdr, phnum, entry); } if (argv[0] != NULL) _rtld_objmain->path = xstrdup(argv[0]); else _rtld_objmain->path = xstrdup("main program"); _rtld_objmain->mainprog = true; /* * Get the actual dynamic linker pathname from the executable if * possible. (It should always be possible.) That ensures that * gdb will find the right dynamic linker even if a non-standard * one is being used. */ if (_rtld_objmain->interp != NULL && strcmp(_rtld_objmain->interp, _rtld_objself.path) != 0) { free(_rtld_objself.path); _rtld_objself.path = xstrdup(_rtld_objmain->interp); } _rtld_digest_dynamic(_rtld_objmain); _rtld_linkmap_add(_rtld_objmain); _rtld_linkmap_add(&_rtld_objself); /* Link the main program into the list of objects. */ *_rtld_objtail = _rtld_objmain; _rtld_objtail = &_rtld_objmain->next; ++_rtld_objmain->refcount; /* Initialize a fake symbol for resolving undefined weak references. */ _rtld_sym_zero.st_info = ELF_ST_INFO(STB_GLOBAL, STT_NOTYPE); _rtld_sym_zero.st_shndx = SHN_ABS; /* * Pre-load user-specified objects after the main program but before * any shared object dependencies. */ dbg(("preloading objects")); if (_rtld_trust && _rtld_preload(getenv("LD_PRELOAD"), true) == -1) _rtld_die(); dbg(("loading needed objects")); if (_rtld_load_needed_objects(_rtld_objmain, RTLD_GLOBAL, true) == -1) _rtld_die(); for (obj = _rtld_objlist; obj != NULL; obj = obj->next) _rtld_objlist_add(&_rtld_list_main, obj); dbg(("relocating objects")); if (_rtld_relocate_objects(_rtld_objmain, bind_now, true) == -1) _rtld_die(); dbg(("doing copy relocations")); if (_rtld_do_copy_relocations(_rtld_objmain, true) == -1) _rtld_die(); /* * Set the __progname, environ and, __mainprog_obj before * calling anything that might use them. */ real___progname = _rtld_objmain_sym("__progname"); if (real___progname) { if ((*real___progname = strrchr(argv[0], '/')) == NULL) (*real___progname) = argv[0]; else (*real___progname)++; } real_environ = _rtld_objmain_sym("environ"); if (real_environ) *real_environ = environ; real___mainprog_obj = _rtld_objmain_sym("__mainprog_obj"); if (real___mainprog_obj) *real___mainprog_obj = _rtld_objmain; dbg(("calling _init functions")); _rtld_call_init_functions(_rtld_objmain->next); dbg(("control at program entry point = %p, obj = %p, exit = %p", _rtld_objmain->entry, _rtld_objmain, _rtld_exit)); /* * Return with the entry point and the exit procedure in at the top * of stack. */ _rtld_debug_state(); /* say hello to gdb! */ ((void **) osp)[0] = _rtld_exit; ((void **) osp)[1] = _rtld_objmain; return (Elf_Addr) _rtld_objmain->entry; } void _rtld_die() { const char *msg = _rtld_dlerror(); if (msg == NULL) msg = "Fatal error"; xerrx(1, "%s\n", msg); } static Obj_Entry * _rtld_dlcheck(handle) void *handle; { Obj_Entry *obj; for (obj = _rtld_objlist; obj != NULL; obj = obj->next) if (obj == (Obj_Entry *) handle) break; if (obj == NULL || obj->dl_refcount == 0) { xwarnx("Invalid shared object handle %p", handle); return NULL; } return obj; } static void _rtld_init_dag(root) Obj_Entry *root; { _rtld_curmark++; _rtld_init_dag1(root, root); } static void _rtld_init_dag1(root, obj) Obj_Entry *root; Obj_Entry *obj; { const Needed_Entry *needed; if (obj->mark == _rtld_curmark) return; obj->mark = _rtld_curmark; _rtld_objlist_add(&obj->dldags, root); _rtld_objlist_add(&root->dagmembers, obj); for (needed = obj->needed; needed != NULL; needed = needed->next) if (needed->obj != NULL) _rtld_init_dag1(root, needed->obj); } /* * Note, this is called only for objects loaded by dlopen(). */ static void _rtld_unload_object(root, do_fini_funcs) Obj_Entry *root; bool do_fini_funcs; { _rtld_unref_dag(root); if (root->refcount == 0) { /* We are finished with some objects. */ Obj_Entry *obj; Obj_Entry **linkp; Objlist_Entry *elm; /* Finalize objects that are about to be unmapped. */ if (do_fini_funcs) for (obj = _rtld_objlist->next; obj != NULL; obj = obj->next) if (obj->refcount == 0 && obj->fini != NULL) (*obj->fini)(); /* Remove the DAG from all objects' DAG lists. */ for (elm = SIMPLEQ_FIRST(&root->dagmembers); elm; elm = SIMPLEQ_NEXT(elm, link)) _rtld_objlist_remove(&elm->obj->dldags, root); /* Remove the DAG from the RTLD_GLOBAL list. */ _rtld_objlist_remove(&_rtld_list_global, root); /* Unmap all objects that are no longer referenced. */ linkp = &_rtld_objlist->next; while ((obj = *linkp) != NULL) { if (obj->refcount == 0) { #ifdef RTLD_DEBUG dbg(("unloading \"%s\"", obj->path)); #endif munmap(obj->mapbase, obj->mapsize); _rtld_objlist_remove(&_rtld_list_global, obj); _rtld_linkmap_delete(obj); *linkp = obj->next; _rtld_obj_free(obj); } else linkp = &obj->next; } _rtld_objtail = linkp; } } static void _rtld_unref_dag(root) Obj_Entry *root; { assert(root); assert(root->refcount != 0); --root->refcount; if (root->refcount == 0) { const Needed_Entry *needed; for (needed = root->needed; needed != NULL; needed = needed->next) { if (needed->obj != NULL) _rtld_unref_dag(needed->obj); } } } int _rtld_dlclose(handle) void *handle; { Obj_Entry *root = _rtld_dlcheck(handle); if (root == NULL) return -1; _rtld_debug.r_state = RT_DELETE; _rtld_debug_state(); --root->dl_refcount; _rtld_unload_object(root, true); _rtld_debug.r_state = RT_CONSISTENT; _rtld_debug_state(); return 0; } char * _rtld_dlerror() { char *msg = error_message; error_message = NULL; return msg; } void * _rtld_dlopen(name, mode) const char *name; int mode; { Obj_Entry **old_obj_tail = _rtld_objtail; Obj_Entry *obj = NULL; _rtld_debug.r_state = RT_ADD; _rtld_debug_state(); if (name == NULL) { obj = _rtld_objmain; obj->refcount++; } else { char *path = _rtld_find_library(name, _rtld_objmain); if (path != NULL) obj = _rtld_load_object(path, mode, true); } if (obj != NULL) { ++obj->dl_refcount; if (*old_obj_tail != NULL) { /* We loaded something new. */ assert(*old_obj_tail == obj); if (_rtld_load_needed_objects(obj, mode, true) == -1 || (_rtld_init_dag(obj), _rtld_relocate_objects(obj, ((mode & 3) == RTLD_NOW), true)) == -1) { _rtld_unload_object(obj, false); obj->dl_refcount--; obj = NULL; } else _rtld_call_init_functions(obj); } } _rtld_debug.r_state = RT_CONSISTENT; _rtld_debug_state(); return obj; } /* * Find a symbol in the main program. */ void * _rtld_objmain_sym(name) const char *name; { unsigned long hash; const Elf_Sym *def; const Obj_Entry *obj; hash = _rtld_elf_hash(name); obj = _rtld_objmain; _rtld_curmark++; def = _rtld_symlook_list(name, hash, &_rtld_list_main, &obj, true); if (def != NULL) return obj->relocbase + def->st_value; return(NULL); } void * _rtld_dlsym(handle, name) void *handle; const char *name; { const Obj_Entry *obj; unsigned long hash; const Elf_Sym *def; const Obj_Entry *defobj; hash = _rtld_elf_hash(name); def = NULL; defobj = NULL; if (handle == NULL #if 0 || handle == RTLD_NEXT #endif ) { void *retaddr; retaddr = __builtin_return_address(0); /* __GNUC__ only */ if ((obj = _rtld_obj_from_addr(retaddr)) == NULL) { _rtld_error("Cannot determine caller's shared object"); return NULL; } if (handle == NULL) { /* Just the caller's shared object. */ def = _rtld_symlook_obj(name, hash, obj, true); defobj = obj; } else { /* All the shared objects after the caller's */ while ((obj = obj->next) != NULL) { if ((def = _rtld_symlook_obj(name, hash, obj, true)) != NULL) { defobj = obj; break; } } } } else { if ((obj = _rtld_dlcheck(handle)) == NULL) return NULL; if (obj->mainprog) { /* Search main program and all libraries loaded by it. */ _rtld_curmark++; def = _rtld_symlook_list(name, hash, &_rtld_list_main, &defobj, true); } else { /* * XXX - This isn't correct. The search should include the whole * DAG rooted at the given object. */ def = _rtld_symlook_obj(name, hash, obj, true); defobj = obj; } } if (def != NULL) return defobj->relocbase + def->st_value; _rtld_error("Undefined symbol \"%s\"", name); return NULL; } int _rtld_dladdr(addr, info) const void *addr; Dl_info *info; { const Obj_Entry *obj; const Elf_Sym *def; void *symbol_addr; unsigned long symoffset; obj = _rtld_obj_from_addr(addr); if (obj == NULL) { _rtld_error("No shared object contains address"); return 0; } info->dli_fname = obj->path; info->dli_fbase = obj->mapbase; info->dli_saddr = (void *)0; info->dli_sname = NULL; /* * Walk the symbol list looking for the symbol whose address is * closest to the address sent in. */ for (symoffset = 0; symoffset < obj->nchains; symoffset++) { def = obj->symtab + symoffset; /* * For skip the symbol if st_shndx is either SHN_UNDEF or * SHN_COMMON. */ if (def->st_shndx == SHN_UNDEF || def->st_shndx == SHN_COMMON) continue; /* * If the symbol is greater than the specified address, or if it * is further away from addr than the current nearest symbol, * then reject it. */ symbol_addr = obj->relocbase + def->st_value; if (symbol_addr > addr || symbol_addr < info->dli_saddr) continue; /* Update our idea of the nearest symbol. */ info->dli_sname = obj->strtab + def->st_name; info->dli_saddr = symbol_addr; /* Exact match? */ if (info->dli_saddr == addr) break; } return 1; } /* * Error reporting function. Use it like printf. If formats the message * into a buffer, and sets things up so that the next call to dlerror() * will return the message. */ void #ifdef __STDC__ _rtld_error(const char *fmt,...) #else _rtld_error(va_alist) va_dcl #endif { static char buf[512]; va_list ap; #ifdef __STDC__ va_start(ap, fmt); #else const char *fmt; va_start(ap); fmt = va_arg(ap, const char *); #endif xvsnprintf(buf, sizeof buf, fmt, ap); error_message = buf; va_end(ap); } void _rtld_debug_state() { /* do nothing */ } void _rtld_linkmap_add(obj) Obj_Entry *obj; { struct link_map *l = &obj->linkmap; struct link_map *prev; obj->linkmap.l_name = obj->path; obj->linkmap.l_addr = obj->mapbase; obj->linkmap.l_ld = obj->dynamic; #ifdef __mips__ /* GDB needs load offset on MIPS to use the symbols */ obj->linkmap.l_offs = obj->relocbase; #endif #ifdef __vax__ /* VAX shared libaries don't start at a vaddr of 0 */ obj->linkmap.l_addr -= obj->vaddrbase; #endif if (_rtld_debug.r_map == NULL) { _rtld_debug.r_map = l; return; } for (prev = _rtld_debug.r_map; prev->l_next != NULL; prev = prev->l_next); l->l_prev = prev; prev->l_next = l; l->l_next = NULL; } void _rtld_linkmap_delete(obj) Obj_Entry *obj; { struct link_map *l = &obj->linkmap; if (l->l_prev == NULL) { if ((_rtld_debug.r_map = l->l_next) != NULL) l->l_next->l_prev = NULL; return; } if ((l->l_prev->l_next = l->l_next) != NULL) l->l_next->l_prev = l->l_prev; } static Obj_Entry * _rtld_obj_from_addr(const void *addr) { unsigned long endhash; Obj_Entry *obj; endhash = _rtld_elf_hash(END_SYM); for (obj = _rtld_objlist; obj != NULL; obj = obj->next) { const Elf_Sym *endsym; if (addr < (void *) obj->mapbase) continue; if ((endsym = _rtld_symlook_obj(END_SYM, endhash, obj, true)) == NULL) continue; /* No "end" symbol?! */ if (addr < (void *) (obj->relocbase + endsym->st_value)) return obj; } return NULL; } static void _rtld_objlist_remove(list, obj) Objlist *list; Obj_Entry *obj; { Objlist_Entry *elm; if ((elm = _rtld_objlist_find(list, obj)) != NULL) { if ((list)->sqh_first == (elm)) { SIMPLEQ_REMOVE_HEAD(list, elm, link); } else { struct Struct_Objlist_Entry *curelm = (list)->sqh_first; while (curelm->link.sqe_next != (elm)) curelm = curelm->link.sqe_next; if((curelm->link.sqe_next = curelm->link.sqe_next->link.sqe_next) == NULL) (list)->sqh_last = &(curelm)->link.sqe_next; } free(elm); } }