/* * CDDL HEADER START * * The contents of this file are subject to the terms of the * Common Development and Distribution License (the "License"). * You may not use this file except in compliance with the License. * * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE * or http://www.opensolaris.org/os/licensing. * See the License for the specific language governing permissions * and limitations under the License. * * When distributing Covered Code, include this CDDL HEADER in each * file and include the License file at usr/src/OPENSOLARIS.LICENSE. * If applicable, add the following below this CDDL HEADER, with the * fields enclosed by brackets "[]" replaced with your own identifying * information: Portions Copyright [yyyy] [name of copyright owner] * * CDDL HEADER END */ /* * Copyright (c) 1988 AT&T * All Rights Reserved * * * Copyright 2008 Sun Microsystems, Inc. All rights reserved. * Use is subject to license terms. */ #pragma ident "%Z%%M% %I% %E% SMI" /* * Symbol table management routines */ #include #include #include #include "msg.h" #include "_libld.h" /* * AVL tree comparator function: * * The primary key is the 'sa_hashval' with a secondary * key of the symbol name itself. */ int ld_sym_avl_comp(const void *elem1, const void *elem2) { int res; Sym_avlnode *sav1 = (Sym_avlnode *)elem1; Sym_avlnode *sav2 = (Sym_avlnode *)elem2; res = sav1->sav_hash - sav2->sav_hash; if (res < 0) return (-1); if (res > 0) return (1); /* * Hash is equal - now compare name */ res = strcmp(sav1->sav_name, sav2->sav_name); if (res == 0) return (0); if (res > 0) return (1); return (-1); } /* * Focal point for verifying symbol names. */ inline static const char * string(Ofl_desc *ofl, Ifl_desc *ifl, Sym *sym, const char *strs, size_t strsize, int symndx, Word shndx, const char *symsecname, const char *strsecname, Word *flags) { const char *regname; Word name = sym->st_name; if (name) { if ((ifl->ifl_flags & FLG_IF_HSTRTAB) == 0) { eprintf(ofl->ofl_lml, ERR_FATAL, MSG_INTL(MSG_FIL_NOSTRTABLE), ifl->ifl_name, symsecname, symndx, EC_XWORD(name)); return (0); } if (name >= (Word)strsize) { eprintf(ofl->ofl_lml, ERR_FATAL, MSG_INTL(MSG_FIL_EXCSTRTABLE), ifl->ifl_name, symsecname, symndx, EC_XWORD(name), strsecname, EC_XWORD(strsize)); return (0); } } /* * Determine if we're dealing with a register and if so validate it. * If it's a scratch register, a fabricated name will be returned. */ if ((regname = ld_is_regsym(ofl, ifl, sym, strs, symndx, shndx, symsecname, flags)) == (const char *)S_ERROR) { return (0); } if (regname) return (regname); /* * If this isn't a register, but we have a global symbol with a null * name, we're not going to be able to hash this, search for it, or * do anything interesting. However, we've been accepting a symbol of * this kind for ages now, so give the user a warning (rather than a * fatal error), just in case this instance exists somewhere in the * world and hasn't, as yet, been a problem. */ if ((name == 0) && (ELF_ST_BIND(sym->st_info) != STB_LOCAL)) { eprintf(ofl->ofl_lml, ERR_WARNING, MSG_INTL(MSG_FIL_NONAMESYM), ifl->ifl_name, symsecname, symndx, EC_XWORD(name)); } return (strs + name); } /* * Shared objects can be built that define specific symbols that can not be * directly bound to. These objects have a syminfo section (and an associated * DF_1_NODIRECT dynamic flags entry). Scan this table looking for symbols * that can't be bound to directly, and if this files symbol is presently * referenced, mark it so that we don't directly bind to it. */ uintptr_t ld_sym_nodirect(Is_desc *isp, Ifl_desc *ifl, Ofl_desc *ofl) { Shdr *sifshdr, *symshdr; Syminfo *sifdata; Sym *symdata; char *strdata; ulong_t cnt, _cnt; /* * Get the syminfo data, and determine the number of entries. */ sifshdr = isp->is_shdr; sifdata = (Syminfo *)isp->is_indata->d_buf; cnt = sifshdr->sh_size / sifshdr->sh_entsize; /* * Get the associated symbol table. */ symshdr = ifl->ifl_isdesc[sifshdr->sh_link]->is_shdr; symdata = ifl->ifl_isdesc[sifshdr->sh_link]->is_indata->d_buf; /* * Get the string table associated with the symbol table. */ strdata = ifl->ifl_isdesc[symshdr->sh_link]->is_indata->d_buf; /* * Traverse the syminfo data for symbols that can't be directly * bound to. */ for (_cnt = 1, sifdata++; _cnt < cnt; _cnt++, sifdata++) { Sym *sym; char *str; Sym_desc *sdp; if ((sifdata->si_flags & SYMINFO_FLG_NOEXTDIRECT) == 0) continue; sym = (Sym *)(symdata + _cnt); str = (char *)(strdata + sym->st_name); if (sdp = ld_sym_find(str, SYM_NOHASH, 0, ofl)) { if (ifl != sdp->sd_file) continue; sdp->sd_flags1 &= ~FLG_SY1_DIR; sdp->sd_flags1 |= FLG_SY1_NDIR; } } return (0); } /* * If, during symbol processing, it is necessary to update a local symbols * contents before we have generated the symbol tables in the output image, * create a new symbol structure and copy the original symbol contents. While * we are processing the input files, their local symbols are part of the * read-only mapped image. Commonly, these symbols are copied to the new output * file image and then updated to reflect their new address and any change in * attributes. However, sometimes during relocation counting, it is necessary * to adjust the symbols information. This routine provides for the generation * of a new symbol image so that this update can be performed. * All global symbols are copied to an internal symbol table to improve locality * of reference and hence performance, and thus this copying is not necessary. */ uintptr_t ld_sym_copy(Sym_desc *sdp) { Sym *nsym; if (sdp->sd_flags & FLG_SY_CLEAN) { if ((nsym = libld_malloc(sizeof (Sym))) == 0) return (S_ERROR); *nsym = *(sdp->sd_sym); sdp->sd_sym = nsym; sdp->sd_flags &= ~FLG_SY_CLEAN; } return (1); } /* * Finds a given name in the link editors internal symbol table. If no * hash value is specified it is calculated. A pointer to the located * Sym_desc entry is returned, or NULL if the symbol is not found. */ Sym_desc * ld_sym_find(const char *name, Word hash, avl_index_t *where, Ofl_desc *ofl) { Sym_avlnode qsav; Sym_avlnode *sav; if (hash == SYM_NOHASH) /* LINTED */ hash = (Word)elf_hash((const char *)name); qsav.sav_hash = hash; qsav.sav_name = name; /* * Perform search for symbol in AVL tree. Note that the 'where' field * is passed in from the caller. If a 'where' is present, it can be * used in subsequent 'ld_sym_enter()' calls if required. */ sav = avl_find(&ofl->ofl_symavl, &qsav, where); /* * If symbol was not found in the avl tree, return null to show that. */ if (sav == 0) return (0); /* * Return symbol found. */ return (sav->sav_symdesc); } /* * Enter a new symbol into the link editors internal symbol table. * If the symbol is from an input file, information regarding the input file * and input section is also recorded. Otherwise (file == NULL) the symbol * has been internally generated (ie. _etext, _edata, etc.). */ Sym_desc * ld_sym_enter(const char *name, Sym *osym, Word hash, Ifl_desc *ifl, Ofl_desc *ofl, Word ndx, Word shndx, Word sdflags, Half sdflags1, avl_index_t *where) { Sym_desc *sdp; Sym_aux *sap; Sym_avlnode *savl; char *_name; Sym *nsym; Half etype; uchar_t vis; avl_index_t _where; /* * Establish the file type. */ if (ifl) etype = ifl->ifl_ehdr->e_type; else etype = ET_NONE; ofl->ofl_entercnt++; /* * Allocate a Sym Descriptor, Auxiliary Descriptor, and a Sym AVLNode - * contiguously. */ if ((savl = libld_calloc(sizeof (Sym_avlnode) + sizeof (Sym_desc) + sizeof (Sym_aux), 1)) == 0) return ((Sym_desc *)S_ERROR); sdp = (Sym_desc *)((uintptr_t)savl + sizeof (Sym_avlnode)); sap = (Sym_aux *)((uintptr_t)sdp + sizeof (Sym_desc)); savl->sav_symdesc = sdp; sdp->sd_file = ifl; sdp->sd_aux = sap; savl->sav_hash = sap->sa_hash = hash; /* * Copy the symbol table entry from the input file into the internal * entry and have the symbol descriptor use it. */ sdp->sd_sym = nsym = &sap->sa_sym; *nsym = *osym; sdp->sd_shndx = shndx; sdp->sd_flags |= sdflags; sdp->sd_flags1 |= sdflags1; if ((_name = libld_malloc(strlen(name) + 1)) == 0) return ((Sym_desc *)S_ERROR); savl->sav_name = sdp->sd_name = (const char *)strcpy(_name, name); /* * Enter Symbol in AVL tree. */ if (where == 0) { /* LINTED */ Sym_avlnode *_savl; /* * If a previous ld_sym_find() hasn't initialized 'where' do it * now. */ where = &_where; _savl = avl_find(&ofl->ofl_symavl, savl, where); assert(_savl == 0); } avl_insert(&ofl->ofl_symavl, savl, *where); /* * Record the section index. This is possible because the * `ifl_isdesc' table is filled before we start symbol processing. */ if ((sdflags & FLG_SY_SPECSEC) || (nsym->st_shndx == SHN_UNDEF)) sdp->sd_isc = NULL; else { sdp->sd_isc = ifl->ifl_isdesc[shndx]; /* * If this symbol is from a relocatable object, make sure that * it is still associated with a section. For example, an * unknown section type (SHT_NULL) would have been rejected on * input with a warning. Here, we make the use of the symbol * fatal. A symbol descriptor is still returned, so that the * caller can continue processing all symbols, and hence flush * out as many error conditions as possible. */ if ((etype == ET_REL) && (sdp->sd_isc == 0)) { eprintf(ofl->ofl_lml, ERR_FATAL, MSG_INTL(MSG_SYM_INVSEC), name, ifl->ifl_name, EC_XWORD(shndx)); ofl->ofl_flags |= FLG_OF_FATAL; return (sdp); } } /* * Mark any COMMON symbols as 'tentative'. */ if (sdflags & FLG_SY_SPECSEC) { if (nsym->st_shndx == SHN_COMMON) sdp->sd_flags |= FLG_SY_TENTSYM; #if defined(__x86) && defined(_ELF64) else if (nsym->st_shndx == SHN_X86_64_LCOMMON) sdp->sd_flags |= FLG_SY_TENTSYM; #endif } /* * Establish the symbols visibility and reference. */ vis = ELF_ST_VISIBILITY(nsym->st_other); if ((etype == ET_NONE) || (etype == ET_REL)) { switch (vis) { case STV_DEFAULT: sdp->sd_flags1 |= FLG_SY1_DEFAULT; break; case STV_INTERNAL: case STV_HIDDEN: sdp->sd_flags1 |= FLG_SY1_HIDDEN; break; case STV_PROTECTED: sdp->sd_flags1 |= FLG_SY1_PROTECT; break; case STV_EXPORTED: sdp->sd_flags1 |= FLG_SY1_EXPORT; break; case STV_SINGLETON: sdp->sd_flags1 |= (FLG_SY1_SINGLE | FLG_SY1_NDIR); ofl->ofl_flags1 |= FLG_OF1_NDIRECT; break; case STV_ELIMINATE: sdp->sd_flags1 |= (FLG_SY1_HIDDEN | FLG_SY1_ELIM); break; default: assert(vis <= STV_ELIMINATE); } sdp->sd_ref = REF_REL_NEED; /* * Under -Bnodirect, all exported interfaces that have not * explicitly been defined protected or directly bound to, are * tagged to prevent direct binding. */ if ((ofl->ofl_flags1 & FLG_OF1_ALNODIR) && ((sdp->sd_flags1 & (FLG_SY1_PROTECT | FLG_SY1_DIR)) == 0) && (nsym->st_shndx != SHN_UNDEF)) { sdp->sd_flags1 |= FLG_SY1_NDIR; } } else { sdp->sd_ref = REF_DYN_SEEN; /* * Record the binding file for this symbol in the sa_bindto * field. If this symbol is ever overridden by a REF_REL_NEED * definition, sa_bindto is used when building a 'translator'. */ if (nsym->st_shndx != SHN_UNDEF) sdp->sd_aux->sa_bindto = ifl; /* * If this is a protected symbol, remember this. Note, this * state is different from the FLG_SY1_PROTECT used to establish * a symbol definitions visibility. This state is used to warn * against possible copy relocations against this referenced * symbol. */ if (vis == STV_PROTECTED) sdp->sd_flags |= FLG_SY_PROT; /* * If this is a SINGLETON definition, then indicate the symbol * can not be directly bound to, and retain the visibility. * This visibility will be inherited by any references made to * this symbol. */ if ((vis == STV_SINGLETON) && (nsym->st_shndx != SHN_UNDEF)) sdp->sd_flags1 |= (FLG_SY1_SINGLE | FLG_SY1_NDIR); /* * If the new symbol is from a shared library and is associated * with a SHT_NOBITS section then this symbol originated from a * tentative symbol. */ if (sdp->sd_isc && (sdp->sd_isc->is_shdr->sh_type == SHT_NOBITS)) sdp->sd_flags |= FLG_SY_TENTSYM; } /* * Reclassify any SHN_SUNW_IGNORE symbols to SHN_UNDEF so as to * simplify future processing. */ if (nsym->st_shndx == SHN_SUNW_IGNORE) { sdp->sd_shndx = shndx = SHN_UNDEF; sdp->sd_flags |= FLG_SY_REDUCED; sdp->sd_flags1 |= (FLG_SY1_HIDDEN | FLG_SY1_IGNORE | FLG_SY1_ELIM); } /* * If this is an undefined, or common symbol from a relocatable object * determine whether it is a global or weak reference (see build_osym(), * where REF_DYN_NEED definitions are returned back to undefines). */ if ((etype == ET_REL) && (ELF_ST_BIND(nsym->st_info) == STB_GLOBAL) && ((nsym->st_shndx == SHN_UNDEF) || ((sdflags & FLG_SY_SPECSEC) && #if defined(__x86) && defined(_ELF64) ((nsym->st_shndx == SHN_COMMON) || (nsym->st_shndx == SHN_X86_64_LCOMMON))))) #else /* BEGIN CSTYLED */ (nsym->st_shndx == SHN_COMMON)))) /* END CSTYLED */ #endif sdp->sd_flags |= FLG_SY_GLOBREF; /* * Record the input filename on the referenced or defined files list * for possible later diagnostics. The `sa_rfile' pointer contains the * name of the file that first referenced this symbol and is used to * generate undefined symbol diagnostics (refer to sym_undef_entry()). * Note that this entry can be overridden if a reference from a * relocatable object is found after a reference from a shared object * (refer to sym_override()). * The `sa_dfiles' list is used to maintain the list of files that * define the same symbol. This list can be used for two reasons: * * o To save the first definition of a symbol that is not available * for this link-edit. * * o To save all definitions of a symbol when the -m option is in * effect. This is optional as it is used to list multiple * (interposed) definitions of a symbol (refer to ldmap_out()), * and can be quite expensive. */ if (nsym->st_shndx == SHN_UNDEF) { sap->sa_rfile = ifl->ifl_name; } else { if (sdp->sd_ref == REF_DYN_SEEN) { /* * A symbol is determined to be unavailable if it * belongs to a version of a shared object that this * user does not wish to use, or if it belongs to an * implicit shared object. */ if (ifl->ifl_vercnt) { Ver_index *vip; Half vndx = ifl->ifl_versym[ndx]; sap->sa_dverndx = vndx; vip = &ifl->ifl_verndx[vndx]; if (!(vip->vi_flags & FLG_VER_AVAIL)) { sdp->sd_flags |= FLG_SY_NOTAVAIL; sap->sa_vfile = ifl->ifl_name; } } if (!(ifl->ifl_flags & FLG_IF_NEEDED)) sdp->sd_flags |= FLG_SY_NOTAVAIL; } else if (etype == ET_REL) { /* * If this symbol has been obtained from a versioned * input relocatable object then the new symbol must be * promoted to the versioning of the output file. */ if (ifl->ifl_versym) ld_vers_promote(sdp, ndx, ifl, ofl); } if ((ofl->ofl_flags & FLG_OF_GENMAP) && ((sdflags & FLG_SY_SPECSEC) == 0)) if (list_appendc(&sap->sa_dfiles, ifl->ifl_name) == 0) return ((Sym_desc *)S_ERROR); } /* * Provided we're not processing a mapfile, diagnose the entered symbol. * Mapfile processing requires the symbol to be updated with additional * information, therefore the diagnosing of the symbol is deferred until * later (see Dbg_map_symbol()). */ if ((ifl == 0) || ((ifl->ifl_flags & FLG_IF_MAPFILE) == 0)) DBG_CALL(Dbg_syms_entered(ofl, nsym, sdp)); return (sdp); } /* * Add a special symbol to the symbol table. Takes special symbol name with * and without underscores. This routine is called, after all other symbol * resolution has completed, to generate a reserved absolute symbol (the * underscore version). Special symbols are updated with the appropriate * values in update_osym(). If the user has already defined this symbol * issue a warning and leave the symbol as is. If the non-underscore symbol * is referenced then turn it into a weak alias of the underscored symbol. * * The bits in flags_u are OR'd into the flags field of the symbol * for the underscored symbol. * * If this is a global symbol, and it hasn't explicitly been defined as being * directly bound to, indicate that it can't be directly bound to. * Historically, most special symbols only have meaning to the object in which * they exist, however, they've always been global. To ensure compatibility * with any unexpected use presently in effect, ensure these symbols don't get * directly bound to. Note, that establishing this state here isn't sufficient * to create a syminfo table, only if a syminfo table is being created by some * other symbol directives will the nodirect binding be recorded. This ensures * we don't create syminfo sections for all objects we create, as this might add * unnecessary bloat to users who haven't explicitly requested extra symbol * information. */ static uintptr_t sym_add_spec(const char *name, const char *uname, Word sdaux_id, Word flags_u, Half flags1, Ofl_desc *ofl) { Sym_desc *sdp; Sym_desc *usdp; Sym *sym; Word hash; avl_index_t where; /* LINTED */ hash = (Word)elf_hash(uname); if (usdp = ld_sym_find(uname, hash, &where, ofl)) { /* * If the underscore symbol exists and is undefined, or was * defined in a shared library, convert it to a local symbol. * Otherwise leave it as is and warn the user. */ if ((usdp->sd_shndx == SHN_UNDEF) || (usdp->sd_ref != REF_REL_NEED)) { usdp->sd_ref = REF_REL_NEED; usdp->sd_shndx = usdp->sd_sym->st_shndx = SHN_ABS; usdp->sd_flags |= FLG_SY_SPECSEC | flags_u; usdp->sd_sym->st_info = ELF_ST_INFO(STB_GLOBAL, STT_OBJECT); usdp->sd_isc = NULL; usdp->sd_sym->st_size = 0; usdp->sd_sym->st_value = 0; /* LINTED */ usdp->sd_aux->sa_symspec = (Half)sdaux_id; /* * If a user hasn't specifically indicated that the * scope of this symbol be made local, then leave it * as global (ie. prevent automatic scoping). The GOT * should be defined protected, whereas all other * special symbols are tagged as no-direct. */ if (((usdp->sd_flags1 & FLG_SY1_HIDDEN) == 0) && (flags1 & FLG_SY1_DEFAULT)) { usdp->sd_aux->sa_overndx = VER_NDX_GLOBAL; if (sdaux_id == SDAUX_ID_GOT) { usdp->sd_flags1 &= ~FLG_SY1_NDIR; usdp->sd_flags1 |= FLG_SY1_PROTECT; usdp->sd_sym->st_other = STV_PROTECTED; } else if ( ((usdp->sd_flags1 & FLG_SY1_DIR) == 0) && ((ofl->ofl_flags & FLG_OF_SYMBOLIC) == 0)) { usdp->sd_flags1 |= FLG_SY1_NDIR; } } usdp->sd_flags1 |= flags1; /* * If the reference originated from a mapfile ensure * we mark the symbol as used. */ if (usdp->sd_flags & FLG_SY_MAPREF) usdp->sd_flags |= FLG_SY_MAPUSED; DBG_CALL(Dbg_syms_updated(ofl, usdp, uname)); } else eprintf(ofl->ofl_lml, ERR_WARNING, MSG_INTL(MSG_SYM_RESERVE), uname, usdp->sd_file->ifl_name); } else { /* * If the symbol does not exist create it. */ if ((sym = libld_calloc(sizeof (Sym), 1)) == 0) return (S_ERROR); sym->st_shndx = SHN_ABS; sym->st_info = ELF_ST_INFO(STB_GLOBAL, STT_OBJECT); sym->st_size = 0; sym->st_value = 0; DBG_CALL(Dbg_syms_created(ofl->ofl_lml, uname)); if ((usdp = ld_sym_enter(uname, sym, hash, (Ifl_desc *)NULL, ofl, 0, SHN_ABS, FLG_SY_SPECSEC | flags_u, 0, &where)) == (Sym_desc *)S_ERROR) return (S_ERROR); usdp->sd_ref = REF_REL_NEED; /* LINTED */ usdp->sd_aux->sa_symspec = (Half)sdaux_id; usdp->sd_aux->sa_overndx = VER_NDX_GLOBAL; if (sdaux_id == SDAUX_ID_GOT) { usdp->sd_flags1 |= FLG_SY1_PROTECT; usdp->sd_sym->st_other = STV_PROTECTED; } else if ((flags1 & FLG_SY1_DEFAULT) && ((ofl->ofl_flags & FLG_OF_SYMBOLIC) == 0)) { usdp->sd_flags1 |= FLG_SY1_NDIR; } usdp->sd_flags1 |= flags1; } if (name && (sdp = ld_sym_find(name, SYM_NOHASH, 0, ofl)) && (sdp->sd_sym->st_shndx == SHN_UNDEF)) { uchar_t bind; /* * If the non-underscore symbol exists and is undefined * convert it to be a local. If the underscore has * sa_symspec set (ie. it was created above) then simulate this * as a weak alias. */ sdp->sd_ref = REF_REL_NEED; sdp->sd_shndx = sdp->sd_sym->st_shndx = SHN_ABS; sdp->sd_flags |= FLG_SY_SPECSEC; sdp->sd_isc = NULL; sdp->sd_sym->st_size = 0; sdp->sd_sym->st_value = 0; /* LINTED */ sdp->sd_aux->sa_symspec = (Half)sdaux_id; if (usdp->sd_aux->sa_symspec) { usdp->sd_aux->sa_linkndx = 0; sdp->sd_aux->sa_linkndx = 0; bind = STB_WEAK; } else bind = STB_GLOBAL; sdp->sd_sym->st_info = ELF_ST_INFO(bind, STT_OBJECT); /* * If a user hasn't specifically indicated the scope of this * symbol be made local then leave it as global (ie. prevent * automatic scoping). The GOT should be defined protected, * whereas all other special symbols are tagged as no-direct. */ if (((sdp->sd_flags1 & FLG_SY1_HIDDEN) == 0) && (flags1 & FLG_SY1_DEFAULT)) { sdp->sd_aux->sa_overndx = VER_NDX_GLOBAL; if (sdaux_id == SDAUX_ID_GOT) { sdp->sd_flags1 &= ~FLG_SY1_NDIR; sdp->sd_flags1 |= FLG_SY1_PROTECT; sdp->sd_sym->st_other = STV_PROTECTED; } else if (((sdp->sd_flags1 & FLG_SY1_DIR) == 0) && ((ofl->ofl_flags & FLG_OF_SYMBOLIC) == 0)) { sdp->sd_flags1 |= FLG_SY1_NDIR; } } sdp->sd_flags1 |= flags1; /* * If the reference originated from a mapfile ensure * we mark the symbol as used. */ if (sdp->sd_flags & FLG_SY_MAPREF) sdp->sd_flags |= FLG_SY_MAPUSED; DBG_CALL(Dbg_syms_updated(ofl, sdp, name)); } return (1); } /* * Print undefined symbols. */ static Boolean undef_title = TRUE; static void sym_undef_title(Ofl_desc *ofl) { eprintf(ofl->ofl_lml, ERR_NONE, MSG_INTL(MSG_SYM_FMT_UNDEF), MSG_INTL(MSG_SYM_UNDEF_ITM_11), MSG_INTL(MSG_SYM_UNDEF_ITM_21), MSG_INTL(MSG_SYM_UNDEF_ITM_12), MSG_INTL(MSG_SYM_UNDEF_ITM_22)); undef_title = FALSE; } /* * Undefined symbols can fall into one of four types: * * o the symbol is really undefined (SHN_UNDEF). * * o versioning has been enabled, however this symbol has not been assigned * to one of the defined versions. * * o the symbol has been defined by an implicitly supplied library, ie. one * which was encounted because it was NEEDED by another library, rather * than from a command line supplied library which would become the only * dependency of the output file being produced. * * o the symbol has been defined by a version of a shared object that is * not permitted for this link-edit. * * In all cases the file who made the first reference to this symbol will have * been recorded via the `sa_rfile' pointer. */ typedef enum { UNDEF, NOVERSION, IMPLICIT, NOTAVAIL, BNDLOCAL } Type; static const Msg format[] = { MSG_SYM_UND_UNDEF, /* MSG_INTL(MSG_SYM_UND_UNDEF) */ MSG_SYM_UND_NOVER, /* MSG_INTL(MSG_SYM_UND_NOVER) */ MSG_SYM_UND_IMPL, /* MSG_INTL(MSG_SYM_UND_IMPL) */ MSG_SYM_UND_NOTA, /* MSG_INTL(MSG_SYM_UND_NOTA) */ MSG_SYM_UND_BNDLOCAL /* MSG_INTL(MSG_SYM_UND_BNDLOCAL) */ }; static void sym_undef_entry(Ofl_desc *ofl, Sym_desc *sdp, Type type) { const char *name1, *name2, *name3; Ifl_desc *ifl = sdp->sd_file; Sym_aux *sap = sdp->sd_aux; if (undef_title) sym_undef_title(ofl); switch (type) { case UNDEF: case BNDLOCAL: name1 = sap->sa_rfile; break; case NOVERSION: name1 = ifl->ifl_name; break; case IMPLICIT: name1 = sap->sa_rfile; name2 = ifl->ifl_name; break; case NOTAVAIL: name1 = sap->sa_rfile; name2 = sap->sa_vfile; name3 = ifl->ifl_verndx[sap->sa_dverndx].vi_name; break; default: return; } eprintf(ofl->ofl_lml, ERR_NONE, MSG_INTL(format[type]), demangle(sdp->sd_name), name1, name2, name3); } /* * At this point all symbol input processing has been completed, therefore * complete the symbol table entries by generating any necessary internal * symbols. */ uintptr_t ld_sym_spec(Ofl_desc *ofl) { Sym_desc *sdp; if (ofl->ofl_flags & FLG_OF_RELOBJ) return (1); DBG_CALL(Dbg_syms_spec_title(ofl->ofl_lml)); if (sym_add_spec(MSG_ORIG(MSG_SYM_ETEXT), MSG_ORIG(MSG_SYM_ETEXT_U), SDAUX_ID_ETEXT, 0, (FLG_SY1_DEFAULT | FLG_SY1_EXPDEF), ofl) == S_ERROR) return (S_ERROR); if (sym_add_spec(MSG_ORIG(MSG_SYM_EDATA), MSG_ORIG(MSG_SYM_EDATA_U), SDAUX_ID_EDATA, 0, (FLG_SY1_DEFAULT | FLG_SY1_EXPDEF), ofl) == S_ERROR) return (S_ERROR); if (sym_add_spec(MSG_ORIG(MSG_SYM_END), MSG_ORIG(MSG_SYM_END_U), SDAUX_ID_END, FLG_SY_DYNSORT, (FLG_SY1_DEFAULT | FLG_SY1_EXPDEF), ofl) == S_ERROR) return (S_ERROR); if (sym_add_spec(MSG_ORIG(MSG_SYM_L_END), MSG_ORIG(MSG_SYM_L_END_U), SDAUX_ID_END, 0, FLG_SY1_HIDDEN, ofl) == S_ERROR) return (S_ERROR); if (sym_add_spec(MSG_ORIG(MSG_SYM_L_START), MSG_ORIG(MSG_SYM_L_START_U), SDAUX_ID_START, 0, FLG_SY1_HIDDEN, ofl) == S_ERROR) return (S_ERROR); /* * Historically we've always produced a _DYNAMIC symbol, even for * static executables (in which case its value will be 0). */ if (sym_add_spec(MSG_ORIG(MSG_SYM_DYNAMIC), MSG_ORIG(MSG_SYM_DYNAMIC_U), SDAUX_ID_DYN, FLG_SY_DYNSORT, (FLG_SY1_DEFAULT | FLG_SY1_EXPDEF), ofl) == S_ERROR) return (S_ERROR); if (OFL_ALLOW_DYNSYM(ofl)) if (sym_add_spec(MSG_ORIG(MSG_SYM_PLKTBL), MSG_ORIG(MSG_SYM_PLKTBL_U), SDAUX_ID_PLT, FLG_SY_DYNSORT, (FLG_SY1_DEFAULT | FLG_SY1_EXPDEF), ofl) == S_ERROR) return (S_ERROR); /* * A GOT reference will be accompanied by the associated GOT symbol. * Make sure it gets assigned the appropriate special attributes. */ if (((sdp = ld_sym_find(MSG_ORIG(MSG_SYM_GOFTBL_U), SYM_NOHASH, 0, ofl)) != 0) && (sdp->sd_ref != REF_DYN_SEEN)) { if (sym_add_spec(MSG_ORIG(MSG_SYM_GOFTBL), MSG_ORIG(MSG_SYM_GOFTBL_U), SDAUX_ID_GOT, FLG_SY_DYNSORT, (FLG_SY1_DEFAULT | FLG_SY1_EXPDEF), ofl) == S_ERROR) return (S_ERROR); } return (1); } /* * This routine checks to see if a symbols visibility needs to be reduced to * either SYMBOLIC or LOCAL. This routine can be called from either * reloc_init() or sym_validate(). */ void ld_sym_adjust_vis(Sym_desc *sdp, Ofl_desc *ofl) { Word oflags = ofl->ofl_flags, oflags1 = ofl->ofl_flags1; Sym *sym = sdp->sd_sym; if ((sdp->sd_ref == REF_REL_NEED) && (sdp->sd_sym->st_shndx != SHN_UNDEF)) { /* * If auto-reduction/elimination is enabled, reduce any * non-versioned global symbols. This routine is called either * from any initial relocation processing that references this * symbol, or from the symbol validation processing. * * A symbol is a candidate for auto-reduction/elimination if: * * . the symbol wasn't explicitly defined within a mapfile * (in which case all the necessary state has been applied * to the symbol), or * . the symbol isn't one of the family of reserved * special symbols (ie. _end, _etext, etc.), or * . the symbol isn't a SINGLETON, or * . the symbol wasn't explicitly defined within a version * definition associated with an input relocatable object. * * Indicate that the symbol has been reduced as it may be * necessary to print these symbols later. */ if (((oflags & FLG_OF_AUTOLCL) || (oflags1 & FLG_OF1_AUTOELM)) && ((sdp->sd_flags1 & MSK_SY1_NOAUTO) == 0)) { if ((sdp->sd_flags1 & FLG_SY1_HIDDEN) == 0) { sdp->sd_flags |= FLG_SY_REDUCED; sdp->sd_flags1 |= FLG_SY1_HIDDEN; } if (ofl->ofl_flags1 & (FLG_OF1_REDLSYM | FLG_OF1_AUTOELM)) { sdp->sd_flags1 |= FLG_SY1_ELIM; sym->st_other = STV_ELIMINATE | (sym->st_other & ~MSK_SYM_VISIBILITY); } else if (ELF_ST_VISIBILITY(sym->st_other) != STV_INTERNAL) sym->st_other = STV_HIDDEN | (sym->st_other & ~MSK_SYM_VISIBILITY); } /* * If -Bsymbolic is in effect, and the symbol hasn't explicitly * been defined nodirect (via a mapfile), then bind the global * symbol symbolically and assign the STV_PROTECTED visibility * attribute. */ if ((oflags & FLG_OF_SYMBOLIC) && ((sdp->sd_flags1 & (FLG_SY1_HIDDEN | FLG_SY1_NDIR)) == 0)) { sdp->sd_flags1 |= FLG_SY1_PROTECT; if (ELF_ST_VISIBILITY(sym->st_other) == STV_DEFAULT) sym->st_other = STV_PROTECTED | (sym->st_other & ~MSK_SYM_VISIBILITY); } } /* * Indicate that this symbol has had it's visibility checked so that * we don't need to do this investigation again. */ sdp->sd_flags |= FLG_SY_VISIBLE; } /* * Make sure a symbol definition is local to the object being built. */ static int ensure_sym_local(Ofl_desc *ofl, Sym_desc *sdp, const char *str) { if (sdp->sd_sym->st_shndx == SHN_UNDEF) { if (str) { eprintf(ofl->ofl_lml, ERR_FATAL, MSG_INTL(MSG_SYM_UNDEF), str, demangle((char *)sdp->sd_name)); } return (1); } if (sdp->sd_ref != REF_REL_NEED) { if (str) { eprintf(ofl->ofl_lml, ERR_FATAL, MSG_INTL(MSG_SYM_EXTERN), str, demangle((char *)sdp->sd_name), sdp->sd_file->ifl_name); } return (1); } sdp->sd_flags |= FLG_SY_UPREQD; if (sdp->sd_isc) { sdp->sd_isc->is_flags |= FLG_IS_SECTREF; sdp->sd_isc->is_file->ifl_flags |= FLG_IF_FILEREF; } return (0); } /* * Make sure all the symbol definitions required for initarray, finiarray, or * preinitarray's are local to the object being built. */ static int ensure_array_local(Ofl_desc *ofl, List *list, const char *str) { Listnode *lnp; Sym_desc *sdp; int ret = 0; for (LIST_TRAVERSE(list, lnp, sdp)) ret += ensure_sym_local(ofl, sdp, str); return (ret); } /* * After all symbol table input processing has been finished, and all relocation * counting has been carried out (ie. no more symbols will be read, generated, * or modified), validate and count the relevant entries: * * o check and print any undefined symbols remaining. Note that * if a symbol has been defined by virtue of the inclusion of * an implicit shared library, it is still classed as undefined. * * o count the number of global needed symbols together with the * size of their associated name strings (if scoping has been * indicated these symbols may be reduced to locals). * * o establish the size and alignment requirements for the global * .bss section (the alignment of this section is based on the * first symbol that it will contain). */ uintptr_t ld_sym_validate(Ofl_desc *ofl) { Sym_avlnode *sav; Sym_desc *sdp; Sym *sym; Word oflags = ofl->ofl_flags; Word undef = 0, needed = 0, verdesc = 0; Xword bssalign = 0, tlsalign = 0; Xword bsssize = 0, tlssize = 0; #if defined(__x86) && defined(_ELF64) Xword lbssalign = 0, lbsssize = 0; #endif int ret; int allow_ldynsym; uchar_t type; /* * If a symbol is undefined and this link-edit calls for no undefined * symbols to remain (this is the default case when generating an * executable but can be enforced for any object using -z defs), the * symbol is classified as undefined and a fatal error condition will * be indicated. * * If the symbol is undefined and we're creating a shared object with * the -Bsymbolic flag, then the symbol is also classified as undefined * and a warning condition will be indicated. */ if ((oflags & (FLG_OF_SHAROBJ | FLG_OF_SYMBOLIC)) == (FLG_OF_SHAROBJ | FLG_OF_SYMBOLIC)) undef = FLG_OF_WARN; if (oflags & FLG_OF_NOUNDEF) undef = FLG_OF_FATAL; /* * If the symbol is referenced from an implicitly included shared object * (ie. it's not on the NEEDED list) then the symbol is also classified * as undefined and a fatal error condition will be indicated. */ if ((oflags & FLG_OF_NOUNDEF) || !(oflags & FLG_OF_SHAROBJ)) needed = FLG_OF_FATAL; /* * If the output image is being versioned all symbol definitions must be * associated with a version. Any symbol that isn't is classified as * undefined and a fatal error condition will be indicated. */ if ((oflags & FLG_OF_VERDEF) && (ofl->ofl_vercnt > VER_NDX_GLOBAL)) verdesc = FLG_OF_FATAL; allow_ldynsym = OFL_ALLOW_LDYNSYM(ofl); if (allow_ldynsym) { /* * Normally, we disallow symbols with 0 size from appearing * in a dyn[sym|tls]sort section. However, there are some * symbols that serve special purposes that we want to exempt * from this rule. Look them up, and set their * FLG_SY_DYNSORT flag. */ static const char *special[] = { MSG_ORIG(MSG_SYM_INIT_U), /* _init */ MSG_ORIG(MSG_SYM_FINI_U), /* _fini */ MSG_ORIG(MSG_SYM_START), /* _start */ NULL }; int i; for (i = 0; special[i] != NULL; i++) { if (((sdp = ld_sym_find(special[i], SYM_NOHASH, 0, ofl)) != NULL) && (sdp->sd_sym->st_size == 0)) { if (ld_sym_copy(sdp) == S_ERROR) return (S_ERROR); sdp->sd_flags |= FLG_SY_DYNSORT; } } } /* * Collect and validate the globals from the internal symbol table. */ for (sav = avl_first(&ofl->ofl_symavl); sav; sav = AVL_NEXT(&ofl->ofl_symavl, sav)) { Is_desc *isp; int undeferr = 0; uchar_t vis; sdp = sav->sav_symdesc; /* * If undefined symbols are allowed ignore any symbols that are * not needed. */ if (!(oflags & FLG_OF_NOUNDEF) && (sdp->sd_ref == REF_DYN_SEEN)) continue; /* * If the symbol originates from an external or parent mapfile * reference and hasn't been matched to a reference from a * relocatable object, ignore it. */ if ((sdp->sd_flags & (FLG_SY_EXTERN | FLG_SY_PARENT)) && ((sdp->sd_flags & FLG_SY_MAPUSED) == 0)) { sdp->sd_flags |= FLG_SY_INVALID; continue; } sym = sdp->sd_sym; type = ELF_ST_TYPE(sym->st_info); /* * Sanity check TLS. */ if ((type == STT_TLS) && (sym->st_size != 0) && (sym->st_shndx != SHN_UNDEF) && (sym->st_shndx != SHN_COMMON)) { Is_desc *isp = sdp->sd_isc; Ifl_desc *ifl = sdp->sd_file; if ((isp == 0) || (isp->is_shdr == 0) || ((isp->is_shdr->sh_flags & SHF_TLS) == 0)) { eprintf(ofl->ofl_lml, ERR_FATAL, MSG_INTL(MSG_SYM_TLS), demangle(sdp->sd_name), ifl->ifl_name); ofl->ofl_flags |= FLG_OF_FATAL; continue; } } if ((sdp->sd_flags & FLG_SY_VISIBLE) == 0) ld_sym_adjust_vis(sdp, ofl); if ((sdp->sd_flags & FLG_SY_REDUCED) && (oflags & FLG_OF_PROCRED)) { DBG_CALL(Dbg_syms_reduce(ofl, DBG_SYM_REDUCE_GLOBAL, sdp, 0, 0)); } /* * Record any STV_SINGLETON existence. */ if ((vis = ELF_ST_VISIBILITY(sym->st_other)) == STV_SINGLETON) ofl->ofl_dtflags_1 |= DF_1_SINGLETON; /* * If building a shared object or executable, and this is a * non-weak UNDEF symbol with reduced visibility (STV_*), then * give a fatal error. */ if (((oflags & FLG_OF_RELOBJ) == 0) && (sym->st_shndx == SHN_UNDEF) && (ELF_ST_BIND(sym->st_info) != STB_WEAK)) { if (vis && (vis != STV_SINGLETON)) { sym_undef_entry(ofl, sdp, BNDLOCAL); ofl->ofl_flags |= FLG_OF_FATAL; continue; } } /* * If this symbol is defined in a non-allocatable section, * reduce it to local symbol. */ if (((isp = sdp->sd_isc) != 0) && isp->is_shdr && ((isp->is_shdr->sh_flags & SHF_ALLOC) == 0)) { sdp->sd_flags |= FLG_SY_REDUCED; sdp->sd_flags1 |= FLG_SY1_HIDDEN; } /* * If this symbol originated as a SHN_SUNW_IGNORE, it will have * been processed as an SHN_UNDEF. Return the symbol to its * original index for validation, and propagation to the output * file. */ if (sdp->sd_flags1 & FLG_SY1_IGNORE) sdp->sd_shndx = SHN_SUNW_IGNORE; if (undef) { /* * If a non-weak reference remains undefined, or if a * mapfile reference is not bound to the relocatable * objects that make up the object being built, we have * a fatal error. * * The exceptions are symbols which are defined to be * found in the parent (FLG_SY_PARENT), which is really * only meaningful for direct binding, or are defined * external (FLG_SY_EXTERN) so as to suppress -zdefs * errors. * * Register symbols are always allowed to be UNDEF. * * Note that we don't include references created via -u * in the same shared object binding test. This is for * backward compatibility, in that a number of archive * makefile rules used -u to cause archive extraction. * These same rules have been cut and pasted to apply * to shared objects, and thus although the -u reference * is redundant, flagging it as fatal could cause some * build to fail. Also we have documented the use of * -u as a mechanism to cause binding to weak version * definitions, thus giving users an error condition * would be incorrect. */ if (!(sdp->sd_flags & FLG_SY_REGSYM) && ((sym->st_shndx == SHN_UNDEF) && ((ELF_ST_BIND(sym->st_info) != STB_WEAK) && ((sdp->sd_flags & (FLG_SY_PARENT | FLG_SY_EXTERN)) == 0)) || (((sdp->sd_flags & (FLG_SY_MAPREF | FLG_SY_MAPUSED)) == FLG_SY_MAPREF) && ((sdp->sd_flags1 & (FLG_SY1_HIDDEN | FLG_SY1_PROTECT)) == 0)))) { sym_undef_entry(ofl, sdp, UNDEF); ofl->ofl_flags |= undef; undeferr = 1; } } else { /* * For building things like shared objects (or anything * -znodefs), undefined symbols are allowed. * * If a mapfile reference remains undefined the user * would probably like a warning at least (they've * usually mis-spelt the reference). Refer to the above * comments for discussion on -u references, which * are not tested for in the same manner. */ if ((sdp->sd_flags & (FLG_SY_MAPREF | FLG_SY_MAPUSED)) == FLG_SY_MAPREF) { sym_undef_entry(ofl, sdp, UNDEF); ofl->ofl_flags |= FLG_OF_WARN; undeferr = 1; } } /* * If this symbol comes from a dependency mark the dependency * as required (-z ignore can result in unused dependencies * being dropped). If we need to record dependency versioning * information indicate what version of the needed shared object * this symbol is part of. Flag the symbol as undefined if it * has not been made available to us. */ if ((sdp->sd_ref == REF_DYN_NEED) && (!(sdp->sd_flags & FLG_SY_REFRSD))) { sdp->sd_file->ifl_flags |= FLG_IF_DEPREQD; /* * Capture that we've bound to a symbol that doesn't * allow being directly bound to. */ if (sdp->sd_flags1 & FLG_SY1_NDIR) ofl->ofl_flags1 |= FLG_OF1_NDIRECT; if (sdp->sd_file->ifl_vercnt) { int vndx; Ver_index *vip; vndx = sdp->sd_aux->sa_dverndx; vip = &sdp->sd_file->ifl_verndx[vndx]; if (vip->vi_flags & FLG_VER_AVAIL) { vip->vi_flags |= FLG_VER_REFER; } else { sym_undef_entry(ofl, sdp, NOTAVAIL); ofl->ofl_flags |= FLG_OF_FATAL; continue; } } } /* * Test that we do not bind to symbol supplied from an implicit * shared object. If a binding is from a weak reference it can * be ignored. */ if (needed && !undeferr && (sdp->sd_flags & FLG_SY_GLOBREF) && (sdp->sd_ref == REF_DYN_NEED) && (sdp->sd_flags & FLG_SY_NOTAVAIL)) { sym_undef_entry(ofl, sdp, IMPLICIT); ofl->ofl_flags |= needed; continue; } /* * Test that a symbol isn't going to be reduced to local scope * which actually wants to bind to a shared object - if so it's * a fatal error. */ if ((sdp->sd_ref == REF_DYN_NEED) && (sdp->sd_flags1 & (FLG_SY1_HIDDEN | FLG_SY1_PROTECT))) { sym_undef_entry(ofl, sdp, BNDLOCAL); ofl->ofl_flags |= FLG_OF_FATAL; continue; } /* * If the output image is to be versioned then all symbol * definitions must be associated with a version. */ if (verdesc && (sdp->sd_ref == REF_REL_NEED) && (sym->st_shndx != SHN_UNDEF) && (!(sdp->sd_flags1 & FLG_SY1_HIDDEN)) && (sdp->sd_aux->sa_overndx == 0)) { sym_undef_entry(ofl, sdp, NOVERSION); ofl->ofl_flags |= verdesc; continue; } /* * If we don't need the symbol there's no need to process it * any further. */ if (sdp->sd_ref == REF_DYN_SEEN) continue; /* * Calculate the size and alignment requirements for the global * .bss and .tls sections. If we're building a relocatable * object only account for scoped COMMON symbols (these will * be converted to .bss references). * * For partially initialized symbol, * if it is expanded, it goes to sunwdata1. * if it is local, it goes to .bss. * if the output is shared object, it goes to .sunwbss. * * Also refer to make_mvsections() in sunwmove.c */ if ((sym->st_shndx == SHN_COMMON) && (((oflags & FLG_OF_RELOBJ) == 0) || ((sdp->sd_flags1 & FLG_SY1_HIDDEN) && (oflags & FLG_OF_PROCRED)))) { int countbss = 0; if (sdp->sd_psyminfo == 0) { countbss = 1; } else if ((sdp->sd_flags & FLG_SY_PAREXPN) != 0) { countbss = 0; } else if (ELF_ST_BIND(sym->st_info) == STB_LOCAL) { countbss = 1; } else if ((ofl->ofl_flags & FLG_OF_SHAROBJ) != 0) { countbss = 0; } else countbss = 1; if (countbss) { Xword * size, * align; if (type != STT_TLS) { size = &bsssize; align = &bssalign; } else { size = &tlssize; align = &tlsalign; } *size = (Xword)S_ROUND(*size, sym->st_value) + sym->st_size; if (sym->st_value > *align) *align = sym->st_value; } } #if defined(__x86) && defined(_ELF64) /* * Calculate the size and alignment requirement for the global * .lbss. TLS or partially initialized symbols do not need to be * considered yet. */ if (sym->st_shndx == SHN_X86_64_LCOMMON) { lbsssize = (Xword)S_ROUND(lbsssize, sym->st_value) + sym->st_size; if (sym->st_value > lbssalign) lbssalign = sym->st_value; } #endif /* * If a symbol was referenced via the command line * (ld -u <>, ...), then this counts as a reference against the * symbol. Mark any section that symbol is defined in. */ if (((isp = sdp->sd_isc) != 0) && (sdp->sd_flags & FLG_SY_CMDREF)) { isp->is_flags |= FLG_IS_SECTREF; isp->is_file->ifl_flags |= FLG_IF_FILEREF; } /* * Update the symbol count and the associated name string size. */ if ((sdp->sd_flags1 & FLG_SY1_HIDDEN) && (oflags & FLG_OF_PROCRED)) { /* * If any reductions are being processed, keep a count * of eliminated symbols, and if the symbol is being * reduced to local, count it's size for the .symtab. */ if (sdp->sd_flags1 & FLG_SY1_ELIM) { ofl->ofl_elimcnt++; } else { ofl->ofl_scopecnt++; if ((((sdp->sd_flags & FLG_SY_REGSYM) == 0) || sym->st_name) && (st_insert(ofl->ofl_strtab, sdp->sd_name) == -1)) return (S_ERROR); if (allow_ldynsym && sym->st_name && ldynsym_symtype[type]) { ofl->ofl_dynscopecnt++; if (st_insert(ofl->ofl_dynstrtab, sdp->sd_name) == -1) return (S_ERROR); /* Include it in sort section? */ DYNSORT_COUNT(sdp, sym, type, ++); } } } else { ofl->ofl_globcnt++; /* * Check to see if this global variable should * go into a sort section. Sort sections require * a .SUNW_ldynsym section, so, don't check * unless a .SUNW_ldynsym is allowed. */ if (allow_ldynsym) { DYNSORT_COUNT(sdp, sym, type, ++); } /* * If global direct bindings are in effect, or this * symbol has bound to a dependency which was specified * as requiring direct bindings, and it hasn't * explicitly been defined as a non-direct binding * symbol, mark it. */ if (((ofl->ofl_dtflags_1 & DF_1_DIRECT) || (isp && (isp->is_file->ifl_flags & FLG_IF_DIRECT))) && ((sdp->sd_flags1 & FLG_SY1_NDIR) == 0)) sdp->sd_flags1 |= FLG_SY1_DIR; /* * Insert the symbol name. */ if (((sdp->sd_flags & FLG_SY_REGSYM) == 0) || sym->st_name) { if (st_insert(ofl->ofl_strtab, sdp->sd_name) == -1) return (S_ERROR); if (!(ofl->ofl_flags & FLG_OF_RELOBJ) && (st_insert(ofl->ofl_dynstrtab, sdp->sd_name) == -1)) return (S_ERROR); } /* * If this section offers a global symbol - record that * fact. */ if (isp) { isp->is_flags |= FLG_IS_SECTREF; isp->is_file->ifl_flags |= FLG_IF_FILEREF; } } } /* * If we've encountered a fatal error during symbol validation then * return now. */ if (ofl->ofl_flags & FLG_OF_FATAL) return (1); /* * Now that symbol resolution is completed, scan any register symbols. * From now on, we're only interested in those that contribute to the * output file. */ if (ofl->ofl_regsyms) { int ndx; for (ndx = 0; ndx < ofl->ofl_regsymsno; ndx++) { if ((sdp = ofl->ofl_regsyms[ndx]) == 0) continue; if (sdp->sd_ref != REF_REL_NEED) { ofl->ofl_regsyms[ndx] = 0; continue; } ofl->ofl_regsymcnt++; if (sdp->sd_sym->st_name == 0) sdp->sd_name = MSG_ORIG(MSG_STR_EMPTY); if ((sdp->sd_flags1 & FLG_SY1_HIDDEN) || (ELF_ST_BIND(sdp->sd_sym->st_info) == STB_LOCAL)) ofl->ofl_lregsymcnt++; } } /* * Generate the .bss section now that we know its size and alignment. */ if (bsssize || !(oflags & FLG_OF_RELOBJ)) { if (ld_make_bss(ofl, bsssize, bssalign, MAKE_BSS) == S_ERROR) return (S_ERROR); } if (tlssize) { if (ld_make_bss(ofl, tlssize, tlsalign, MAKE_TLS) == S_ERROR) return (S_ERROR); } #if defined(__x86) && defined(_ELF64) if (lbsssize && !(oflags & FLG_OF_RELOBJ)) { if (ld_make_bss(ofl, lbsssize, lbssalign, MAKE_LBSS) == S_ERROR) return (S_ERROR); } #endif /* * Determine what entry point symbol we need, and if found save its * symbol descriptor so that we can update the ELF header entry with the * symbols value later (see update_oehdr). Make sure the symbol is * tagged to ensure its update in case -s is in effect. Use any -e * option first, or the default entry points `_start' and `main'. */ ret = 0; if (ofl->ofl_entry) { if ((sdp = ld_sym_find(ofl->ofl_entry, SYM_NOHASH, 0, ofl)) == NULL) { eprintf(ofl->ofl_lml, ERR_FATAL, MSG_INTL(MSG_ARG_NOENTRY), ofl->ofl_entry); ret++; } else if (ensure_sym_local(ofl, sdp, MSG_INTL(MSG_SYM_ENTRY)) != 0) { ret++; } else { ofl->ofl_entry = (void *)sdp; } } else if (((sdp = ld_sym_find(MSG_ORIG(MSG_SYM_START), SYM_NOHASH, 0, ofl)) != NULL) && (ensure_sym_local(ofl, sdp, 0) == 0)) { ofl->ofl_entry = (void *)sdp; } else if (((sdp = ld_sym_find(MSG_ORIG(MSG_SYM_MAIN), SYM_NOHASH, 0, ofl)) != NULL) && (ensure_sym_local(ofl, sdp, 0) == 0)) { ofl->ofl_entry = (void *)sdp; } /* * If ld -zdtrace= was given, then validate that the symbol is * defined within the current object being built. */ if ((sdp = ofl->ofl_dtracesym) != 0) ret += ensure_sym_local(ofl, sdp, MSG_ORIG(MSG_STR_DTRACE)); /* * If any initarray, finiarray or preinitarray functions have been * requested, make sure they are defined within the current object * being built. */ if (ofl->ofl_initarray.head) { ret += ensure_array_local(ofl, &ofl->ofl_initarray, MSG_ORIG(MSG_SYM_INITARRAY)); } if (ofl->ofl_finiarray.head) { ret += ensure_array_local(ofl, &ofl->ofl_finiarray, MSG_ORIG(MSG_SYM_FINIARRAY)); } if (ofl->ofl_preiarray.head) { ret += ensure_array_local(ofl, &ofl->ofl_preiarray, MSG_ORIG(MSG_SYM_PREINITARRAY)); } if (ret) return (S_ERROR); /* * If we're required to record any needed dependencies versioning * information calculate it now that all symbols have been validated. */ if ((oflags & (FLG_OF_VERNEED | FLG_OF_NOVERSEC)) == FLG_OF_VERNEED) return (ld_vers_check_need(ofl)); else return (1); } /* * qsort(3c) comparison function. As an optimization for associating weak * symbols to their strong counterparts sort global symbols according to their * address and binding. */ static int compare(const void * sdpp1, const void * sdpp2) { Sym_desc * sdp1 = *((Sym_desc **)sdpp1); Sym_desc * sdp2 = *((Sym_desc **)sdpp2); Sym * sym1, * sym2; uchar_t bind1, bind2; /* * Symbol descriptors may be zero, move these to the front of the * sorted array. */ if (sdp1 == 0) return (-1); if (sdp2 == 0) return (1); sym1 = sdp1->sd_sym; sym2 = sdp2->sd_sym; /* * Compare the symbols value (address). */ if (sym1->st_value > sym2->st_value) return (1); if (sym1->st_value < sym2->st_value) return (-1); bind1 = ELF_ST_BIND(sym1->st_info); bind2 = ELF_ST_BIND(sym2->st_info); /* * If two symbols have the same address place the weak symbol before * any strong counterpart. */ if (bind1 > bind2) return (-1); if (bind1 < bind2) return (1); return (0); } /* * Issue a MSG_SYM_BADADDR error from ld_sym_process(). This error * is issued when a symbol address/size is not contained by the * target section. * * Such objects are at least partially corrupt, and the user would * be well advised to be skeptical of them, and to ask their compiler * supplier to fix the problem. However, a distinction needs to be * made between symbols that reference readonly text, and those that * access writable data. Other than throwing off profiling results, * the readonly section case is less serious. We have encountered * such objects in the field. In order to allow existing objects * to continue working, we issue a warning rather than a fatal error * if the symbol is against readonly text. Other cases are fatal. */ static void issue_badaddr_msg(Ifl_desc *ifl, Ofl_desc *ofl, Sym_desc *sdp, Sym *sym, Word shndx) { Lword flag; Error err; const char *msg; if ((sdp->sd_isc->is_shdr->sh_flags & (SHF_WRITE | SHF_ALLOC)) == SHF_ALLOC) { msg = MSG_INTL(MSG_SYM_BADADDR_ROTXT); flag = FLG_OF_WARN; err = ERR_WARNING; } else { msg = MSG_INTL(MSG_SYM_BADADDR); flag = FLG_OF_FATAL; err = ERR_FATAL; } eprintf(ofl->ofl_lml, err, msg, demangle(sdp->sd_name), ifl->ifl_name, shndx, sdp->sd_isc->is_name, EC_XWORD(sdp->sd_isc->is_shdr->sh_size), EC_XWORD(sym->st_value), EC_XWORD(sym->st_size)); ofl->ofl_flags |= flag; } /* * Process the symbol table for the specified input file. At this point all * input sections from this input file have been assigned an input section * descriptor which is saved in the `ifl_isdesc' array. * * o local symbols are saved (as is) if the input file is a * relocatable object * * o global symbols are added to the linkers internal symbol * table if they are not already present, otherwise a symbol * resolution function is called upon to resolve the conflict. */ uintptr_t ld_sym_process(Is_desc *isc, Ifl_desc *ifl, Ofl_desc *ofl) { /* * This macro tests the given symbol to see if it is out of * range relative to the section it references. * * entry: * - ifl is a relative object (ET_REL) * _sdp - Symbol descriptor * _sym - Symbol * _type - Symbol type * * The following are tested: * - Symbol length is non-zero * - Symbol type is a type that references code or data * - Referenced section is not 0 (indicates an UNDEF symbol) * and is not in the range of special values above SHN_LORESERVE * (excluding SHN_XINDEX, which is OK). * - We have a valid section header for the target section * * If the above are all true, and the symbol position is not * contained by the target section, this macro evaluates to * True (1). Otherwise, False(0). */ #define SYM_LOC_BADADDR(_sdp, _sym, _type) \ (_sym->st_size && dynsymsort_symtype[_type] && \ (_sym->st_shndx != SHN_UNDEF) && \ ((_sym->st_shndx < SHN_LORESERVE) || \ (_sym->st_shndx == SHN_XINDEX)) && \ _sdp->sd_isc && _sdp->sd_isc->is_shdr && \ ((_sym->st_value + _sym->st_size) > _sdp->sd_isc->is_shdr->sh_size)) Conv_inv_buf_t inv_buf; Sym *sym = (Sym *)isc->is_indata->d_buf; Word *symshndx = 0; Shdr *shdr = isc->is_shdr; Sym_desc *sdp; size_t strsize; char *strs; uchar_t type, bind; Word ndx, hash, local, total; Half etype = ifl->ifl_ehdr->e_type; int etype_rel; const char *symsecname, *strsecname; avl_index_t where; int test_gnu_hidden_bit; /* * Its possible that a file may contain more that one symbol table, * ie. .dynsym and .symtab in a shared library. Only process the first * table (here, we assume .dynsym comes before .symtab). */ if (ifl->ifl_symscnt) return (1); if (isc->is_symshndx) symshndx = isc->is_symshndx->is_indata->d_buf; DBG_CALL(Dbg_syms_process(ofl->ofl_lml, ifl)); if (isc->is_name) symsecname = isc->is_name; else symsecname = MSG_ORIG(MSG_STR_EMPTY); /* * From the symbol tables section header information determine which * strtab table is needed to locate the actual symbol names. */ if (ifl->ifl_flags & FLG_IF_HSTRTAB) { ndx = shdr->sh_link; if ((ndx == 0) || (ndx >= ifl->ifl_shnum)) { eprintf(ofl->ofl_lml, ERR_FATAL, MSG_INTL(MSG_FIL_INVSHLINK), ifl->ifl_name, symsecname, EC_XWORD(ndx)); return (S_ERROR); } strsize = ifl->ifl_isdesc[ndx]->is_shdr->sh_size; strs = ifl->ifl_isdesc[ndx]->is_indata->d_buf; if (ifl->ifl_isdesc[ndx]->is_name) strsecname = ifl->ifl_isdesc[ndx]->is_name; else strsecname = MSG_ORIG(MSG_STR_EMPTY); } else { /* * There is no string table section in this input file * although there are symbols in this symbol table section. * This means that these symbols do not have names. * Currently, only scratch register symbols are allowed * not to have names. */ strsize = 0; strs = (char *)MSG_ORIG(MSG_STR_EMPTY); strsecname = MSG_ORIG(MSG_STR_EMPTY); } /* * Determine the number of local symbols together with the total * number we have to process. */ total = (Word)(shdr->sh_size / shdr->sh_entsize); local = shdr->sh_info; /* * Allocate a symbol table index array and a local symbol array * (global symbols are processed and added to the ofl->ofl_symbkt[] * array). If we are dealing with a relocatable object, allocate the * local symbol descriptors. If this isn't a relocatable object we * still have to process any shared object locals to determine if any * register symbols exist. Although these aren't added to the output * image, they are used as part of symbol resolution. */ if ((ifl->ifl_oldndx = libld_malloc((size_t)(total * sizeof (Sym_desc *)))) == 0) return (S_ERROR); etype_rel = (etype == ET_REL); if (etype_rel && local) { if ((ifl->ifl_locs = libld_calloc(sizeof (Sym_desc), local)) == 0) return (S_ERROR); /* LINTED */ ifl->ifl_locscnt = (Word)local; } ifl->ifl_symscnt = total; /* * If there are local symbols to save add them to the symbol table * index array. */ if (local) { int allow_ldynsym = OFL_ALLOW_LDYNSYM(ofl); for (sym++, ndx = 1; ndx < local; sym++, ndx++) { Word shndx, sdflags = FLG_SY_CLEAN; const char *name; Sym_desc *rsdp; /* * Determine the associated section index. */ if (symshndx && (sym->st_shndx == SHN_XINDEX)) shndx = symshndx[ndx]; else if ((shndx = sym->st_shndx) >= SHN_LORESERVE) sdflags |= FLG_SY_SPECSEC; /* * Check if st_name has a valid value or not. */ if ((name = string(ofl, ifl, sym, strs, strsize, ndx, shndx, symsecname, strsecname, &sdflags)) == 0) { ofl->ofl_flags |= FLG_OF_FATAL; continue; } /* * If this local symbol table originates from a shared * object, then we're only interested in recording * register symbols. As local symbol descriptors aren't * allocated for shared objects, one will be allocated * to associated with the register symbol. This symbol * won't become part of the output image, but we must * process it to test for register conflicts. */ rsdp = sdp = 0; if (sdflags & FLG_SY_REGSYM) { if ((rsdp = ld_reg_find(sym, ofl)) != 0) { /* * The fact that another register def- * inition has been found is fatal. * Call the verification routine to get * the error message and move on. */ (void) ld_reg_check(rsdp, sym, name, ifl, ofl); continue; } if (etype == ET_DYN) { if ((sdp = libld_calloc( sizeof (Sym_desc), 1)) == 0) return (S_ERROR); sdp->sd_ref = REF_DYN_SEEN; } } else if (etype == ET_DYN) continue; /* * Fill in the remaining symbol descriptor information. */ if (sdp == 0) { sdp = &(ifl->ifl_locs[ndx]); sdp->sd_ref = REF_REL_NEED; } if (rsdp == 0) { sdp->sd_name = name; sdp->sd_sym = sym; sdp->sd_shndx = shndx; sdp->sd_flags = sdflags; sdp->sd_file = ifl; ifl->ifl_oldndx[ndx] = sdp; } DBG_CALL(Dbg_syms_entry(ofl->ofl_lml, ndx, sdp)); /* * Reclassify any SHN_SUNW_IGNORE symbols to SHN_UNDEF * so as to simplify future processing. */ if (sym->st_shndx == SHN_SUNW_IGNORE) { sdp->sd_shndx = shndx = SHN_UNDEF; sdp->sd_flags1 |= (FLG_SY1_IGNORE | FLG_SY1_ELIM); } /* * Process any register symbols. */ if (sdp->sd_flags & FLG_SY_REGSYM) { /* * Add a diagnostic to indicate we've caught a * register symbol, as this can be useful if a * register conflict is later discovered. */ DBG_CALL(Dbg_syms_entered(ofl, sym, sdp)); /* * If this register symbol hasn't already been * recorded, enter it now. */ if ((rsdp == 0) && (ld_reg_enter(sdp, ofl) == 0)) return (S_ERROR); } /* * Assign an input section. */ if ((sym->st_shndx != SHN_UNDEF) && ((sdp->sd_flags & FLG_SY_SPECSEC) == 0)) sdp->sd_isc = ifl->ifl_isdesc[shndx]; /* * If this symbol falls within the range of a section * being discarded, then discard the symbol itself. * There is no reason to keep this local symbol. */ if (sdp->sd_isc && (sdp->sd_isc->is_flags & FLG_IS_DISCARD)) { sdp->sd_flags |= FLG_SY_ISDISC; DBG_CALL(Dbg_syms_discarded(ofl->ofl_lml, sdp)); continue; } /* * Skip any section symbols as new versions of these * will be created. */ if ((type = ELF_ST_TYPE(sym->st_info)) == STT_SECTION) { if (sym->st_shndx == SHN_UNDEF) { eprintf(ofl->ofl_lml, ERR_WARNING, MSG_INTL(MSG_SYM_INVSHNDX), demangle(sdp->sd_name), ifl->ifl_name, conv_sym_shndx(sym->st_shndx, &inv_buf)); } continue; } /* * For a relocatable object, if this symbol is defined * and has non-zero length and references an address * within an associated section, then check its extents * to make sure the section boundaries encompass it. * If they don't, the ELF file is corrupt. */ if (etype_rel && SYM_LOC_BADADDR(sdp, sym, type)) { issue_badaddr_msg(ifl, ofl, sdp, sym, shndx); continue; } /* * Sanity check for TLS */ if ((sym->st_size != 0) && ((type == STT_TLS) && (sym->st_shndx != SHN_COMMON))) { Is_desc *isp = sdp->sd_isc; if ((isp == 0) || (isp->is_shdr == 0) || ((isp->is_shdr->sh_flags & SHF_TLS) == 0)) { eprintf(ofl->ofl_lml, ERR_FATAL, MSG_INTL(MSG_SYM_TLS), demangle(sdp->sd_name), ifl->ifl_name); ofl->ofl_flags |= FLG_OF_FATAL; continue; } } /* * Carry our some basic sanity checks (these are just * some of the erroneous symbol entries we've come * across, there's probably a lot more). The symbol * will not be carried forward to the output file, which * won't be a problem unless a relocation is required * against it. */ if (((sdp->sd_flags & FLG_SY_SPECSEC) && ((sym->st_shndx == SHN_COMMON)) || ((type == STT_FILE) && (sym->st_shndx != SHN_ABS))) || (sdp->sd_isc && (sdp->sd_isc->is_osdesc == 0))) { eprintf(ofl->ofl_lml, ERR_WARNING, MSG_INTL(MSG_SYM_INVSHNDX), demangle(sdp->sd_name), ifl->ifl_name, conv_sym_shndx(sym->st_shndx, &inv_buf)); sdp->sd_isc = NULL; sdp->sd_flags |= FLG_SY_INVALID; continue; } /* * As these local symbols will become part of the output * image, record their number and name string size. * Globals are counted after all input file processing * (and hence symbol resolution) is complete during * sym_validate(). */ if (!(ofl->ofl_flags1 & FLG_OF1_REDLSYM)) { ofl->ofl_locscnt++; if ((((sdp->sd_flags & FLG_SY_REGSYM) == 0) || sym->st_name) && (st_insert(ofl->ofl_strtab, sdp->sd_name) == -1)) return (S_ERROR); if (allow_ldynsym && sym->st_name && ldynsym_symtype[type]) { ofl->ofl_dynlocscnt++; if (st_insert(ofl->ofl_dynstrtab, sdp->sd_name) == -1) return (S_ERROR); /* Include it in sort section? */ DYNSORT_COUNT(sdp, sym, type, ++); } } } } /* * The GNU ld interprets the top bit of the 16-bit Versym value * (0x8000) as the "hidden" bit. If this bit is set, the linker * is supposed to act as if that symbol does not exist. The Solaris * linker does not support this mechanism, or the model of interface * evolution that it allows, but we honor it in GNU ld produced * objects in order to interoperate with them. * * Determine if we should honor the GNU hidden bit for this file. */ test_gnu_hidden_bit = ((ifl->ifl_flags & FLG_IF_GNUVER) != 0) && (ifl->ifl_versym != NULL); /* * Now scan the global symbols entering them in the internal symbol * table or resolving them as necessary. */ sym = (Sym *)isc->is_indata->d_buf; sym += local; /* LINTED */ for (ndx = (int)local; ndx < total; sym++, ndx++) { const char *name; Word shndx, sdflags = 0; /* * Determine the associated section index. */ if (symshndx && (sym->st_shndx == SHN_XINDEX)) { shndx = symshndx[ndx]; } else { shndx = sym->st_shndx; if (sym->st_shndx >= SHN_LORESERVE) sdflags |= FLG_SY_SPECSEC; } /* * Check if st_name has a valid value or not. */ if ((name = string(ofl, ifl, sym, strs, strsize, ndx, shndx, symsecname, strsecname, &sdflags)) == 0) { ofl->ofl_flags |= FLG_OF_FATAL; continue; } /* * Test for the GNU hidden bit, and ignore symbols that * have it set. */ if (test_gnu_hidden_bit && ((ifl->ifl_versym[ndx] & 0x8000) != 0)) continue; /* * The linker itself will generate symbols for _end, _etext, * _edata, _DYNAMIC and _PROCEDURE_LINKAGE_TABLE_, so don't * bother entering these symbols from shared objects. This * results in some wasted resolution processing, which is hard * to feel, but if nothing else, pollutes diagnostic relocation * output. */ if (name[0] && (etype == ET_DYN) && (sym->st_size == 0) && (ELF_ST_TYPE(sym->st_info) == STT_OBJECT) && (name[0] == '_') && ((name[1] == 'e') || (name[1] == 'D') || (name[1] == 'P')) && ((strcmp(name, MSG_ORIG(MSG_SYM_ETEXT_U)) == 0) || (strcmp(name, MSG_ORIG(MSG_SYM_EDATA_U)) == 0) || (strcmp(name, MSG_ORIG(MSG_SYM_END_U)) == 0) || (strcmp(name, MSG_ORIG(MSG_SYM_DYNAMIC_U)) == 0) || (strcmp(name, MSG_ORIG(MSG_SYM_PLKTBL_U)) == 0))) { ifl->ifl_oldndx[ndx] = 0; continue; } /* * Determine and validate the symbols binding. */ bind = ELF_ST_BIND(sym->st_info); if ((bind != STB_GLOBAL) && (bind != STB_WEAK)) { eprintf(ofl->ofl_lml, ERR_WARNING, MSG_INTL(MSG_SYM_NONGLOB), demangle(name), ifl->ifl_name, conv_sym_info_bind(bind, 0, &inv_buf)); continue; } /* * If this symbol falls within the range of a section being * discarded, then discard the symbol itself. */ if (((sdflags & FLG_SY_SPECSEC) == 0) && (sym->st_shndx != SHN_UNDEF)) { Is_desc *isp; if (shndx >= ifl->ifl_shnum) { /* * Carry our some basic sanity checks * The symbol will not be carried forward to * the output file, which won't be a problem * unless a relocation is required against it. */ eprintf(ofl->ofl_lml, ERR_WARNING, MSG_INTL(MSG_SYM_INVSHNDX), demangle(name), ifl->ifl_name, conv_sym_shndx(sym->st_shndx, &inv_buf)); continue; } isp = ifl->ifl_isdesc[shndx]; if (isp && (isp->is_flags & FLG_IS_DISCARD)) { if ((sdp = libld_calloc(sizeof (Sym_desc), 1)) == 0) return (S_ERROR); /* * Create a dummy symbol entry so that if we * find any references to this discarded symbol * we can compensate. */ sdp->sd_name = name; sdp->sd_sym = sym; sdp->sd_file = ifl; sdp->sd_isc = isp; sdp->sd_flags = FLG_SY_ISDISC; ifl->ifl_oldndx[ndx] = sdp; DBG_CALL(Dbg_syms_discarded(ofl->ofl_lml, sdp)); continue; } } /* * If the symbol does not already exist in the internal symbol * table add it, otherwise resolve the conflict. If the symbol * from this file is kept, retain its symbol table index for * possible use in associating a global alias. */ /* LINTED */ hash = (Word)elf_hash((const char *)name); if ((sdp = ld_sym_find(name, hash, &where, ofl)) == NULL) { DBG_CALL(Dbg_syms_global(ofl->ofl_lml, ndx, name)); if ((sdp = ld_sym_enter(name, sym, hash, ifl, ofl, ndx, shndx, sdflags, 0, &where)) == (Sym_desc *)S_ERROR) return (S_ERROR); } else if (ld_sym_resolve(sdp, sym, ifl, ofl, ndx, shndx, sdflags) == S_ERROR) return (S_ERROR); /* * After we've compared a defined symbol in one shared * object, flag the symbol so we don't compare it again. */ if ((etype == ET_DYN) && (sym->st_shndx != SHN_UNDEF) && ((sdp->sd_flags & FLG_SY_SOFOUND) == 0)) sdp->sd_flags |= FLG_SY_SOFOUND; /* * If the symbol is accepted from this file retain the symbol * index for possible use in aliasing. */ if (sdp->sd_file == ifl) sdp->sd_symndx = ndx; ifl->ifl_oldndx[ndx] = sdp; /* * If we've accepted a register symbol, continue to validate * it. */ if (sdp->sd_flags & FLG_SY_REGSYM) { Sym_desc *rsdp; if ((rsdp = ld_reg_find(sdp->sd_sym, ofl)) == 0) { if (ld_reg_enter(sdp, ofl) == 0) return (S_ERROR); } else if (rsdp != sdp) { (void) ld_reg_check(rsdp, sdp->sd_sym, sdp->sd_name, ifl, ofl); } } /* * For a relocatable object, if this symbol is defined * and has non-zero length and references an address * within an associated section, then check its extents * to make sure the section boundaries encompass it. * If they don't, the ELF file is corrupt. Note that this * global symbol may have come from another file to satisfy * an UNDEF symbol of the same name from this one. In that * case, we don't check it, because it was already checked * as part of its own file. */ if (etype_rel && (sdp->sd_file == ifl)) { Sym *tsym = sdp->sd_sym; if (SYM_LOC_BADADDR(sdp, tsym, ELF_ST_TYPE(tsym->st_info))) { issue_badaddr_msg(ifl, ofl, sdp, tsym, tsym->st_shndx); continue; } } } /* * If this is a shared object scan the globals one more time and * associate any weak/global associations. This association is needed * should the weak definition satisfy a reference in the dynamic * executable: * * o if the symbol is a data item it will be copied to the * executables address space, thus we must also reassociate the * alias symbol with its new location in the executable. * * o if the symbol is a function then we may need to promote the * symbols binding from undefined weak to undefined, otherwise the * run-time linker will not generate the correct relocation error * should the symbol not be found. * * The true association between a weak/strong symbol pair is that both * symbol entries are identical, thus first we created a sorted symbol * list keyed off of the symbols value (if the value is the same chances * are the rest of the symbols data is). This list is then scanned for * weak symbols, and if one is found then any strong association will * exist in the following entries. Thus we just have to scan one * (typical single alias) or more (in the uncommon instance of multiple * weak to strong associations) entries to determine if a match exists. */ if ((OFL_ALLOW_LDYNSYM(ofl) || (etype == ET_DYN)) && (total > local)) { Sym_desc ** sort; size_t size = (total - local) * sizeof (Sym_desc *); if ((sort = libld_malloc(size)) == 0) return (S_ERROR); (void) memcpy((void *)sort, &ifl->ifl_oldndx[local], size); qsort(sort, (total - local), sizeof (Sym_desc *), compare); for (ndx = 0; ndx < (total - local); ndx++) { Sym_desc * wsdp = sort[ndx]; Sym * wsym; int sndx; if (wsdp == 0) continue; wsym = wsdp->sd_sym; if ((ELF_ST_BIND(wsym->st_info) != STB_WEAK) || (wsdp->sd_sym->st_shndx == SHN_UNDEF) || (wsdp->sd_flags & FLG_SY_SPECSEC)) continue; /* * We have a weak symbol, if it has a strong alias it * will have been sorted to one of the following sort * table entries. Note that we could have multiple weak * symbols aliased to one strong (if this occurs then * the strong symbol only maintains one alias back to * the last weak). */ for (sndx = ndx + 1; sndx < (total - local); sndx++) { Sym_desc * ssdp = sort[sndx]; Sym * ssym; if (ssdp == 0) break; ssym = ssdp->sd_sym; if (wsym->st_value != ssym->st_value) break; if ((ssdp->sd_file == ifl) && (wsdp->sd_file == ifl) && (wsym->st_size == ssym->st_size) && (ssdp->sd_sym->st_shndx != SHN_UNDEF) && (ELF_ST_BIND(ssym->st_info) != STB_WEAK) && ((ssdp->sd_flags & FLG_SY_SPECSEC) == 0)) { int w_dynbits, s_dynbits; /* * If a sharable object, set link * fields so they reference each other */ if (etype == ET_DYN) { ssdp->sd_aux->sa_linkndx = (Word)wsdp->sd_symndx; wsdp->sd_aux->sa_linkndx = (Word)ssdp->sd_symndx; } /* * Determine which of these two symbols * go into the sort section. If the * mapfile has made explicit settings * of the FLG_SY_*DYNSORT flags for both * symbols, then we do what they say. * If one has the DYNSORT flags set, * we set the NODYNSORT bit in the * other. And if neither has an * explicit setting, then we favor the * weak symbol because they usually * lack the leading underscore. */ w_dynbits = wsdp->sd_flags & (FLG_SY_DYNSORT | FLG_SY_NODYNSORT); s_dynbits = ssdp->sd_flags & (FLG_SY_DYNSORT | FLG_SY_NODYNSORT); if (!(w_dynbits && s_dynbits)) { if (s_dynbits) { if (s_dynbits == FLG_SY_DYNSORT) wsdp->sd_flags |= FLG_SY_NODYNSORT; } else if (w_dynbits != FLG_SY_NODYNSORT) { ssdp->sd_flags |= FLG_SY_NODYNSORT; } } break; } } } } return (1); #undef SYM_LOC_BADADDR } /* * Add an undefined symbol to the symbol table. The reference originates from * the location identifed by the message id (mid). These references can * originate from command line options such as -e, -u, -initarray, etc. * (identified with MSG_INTL(MSG_STR_COMMAND)), or from internally generated * TLS relocation references (identified with MSG_INTL(MSG_STR_TLSREL)). */ Sym_desc * ld_sym_add_u(const char *name, Ofl_desc *ofl, Msg mid) { Sym *sym; Ifl_desc *ifl = 0, *_ifl; Sym_desc *sdp; Word hash; Listnode *lnp; avl_index_t where; const char *reference = MSG_INTL(mid); /* * As an optimization, determine whether we've already generated this * reference. If the symbol doesn't already exist we'll create it. * Or if the symbol does exist from a different source, we'll resolve * the conflict. */ /* LINTED */ hash = (Word)elf_hash(name); if ((sdp = ld_sym_find(name, hash, &where, ofl)) != NULL) { if ((sdp->sd_sym->st_shndx == SHN_UNDEF) && (sdp->sd_file->ifl_name == reference)) return (sdp); } /* * Determine whether a pseudo input file descriptor exists to represent * the command line, as any global symbol needs an input file descriptor * during any symbol resolution (refer to map_ifl() which provides a * similar method for adding symbols from mapfiles). */ for (LIST_TRAVERSE(&ofl->ofl_objs, lnp, _ifl)) if (strcmp(_ifl->ifl_name, reference) == 0) { ifl = _ifl; break; } /* * If no descriptor exists create one. */ if (ifl == 0) { if ((ifl = libld_calloc(sizeof (Ifl_desc), 1)) == (Ifl_desc *)0) return ((Sym_desc *)S_ERROR); ifl->ifl_name = reference; ifl->ifl_flags = FLG_IF_NEEDED | FLG_IF_FILEREF; if ((ifl->ifl_ehdr = libld_calloc(sizeof (Ehdr), 1)) == 0) return ((Sym_desc *)S_ERROR); ifl->ifl_ehdr->e_type = ET_REL; if (list_appendc(&ofl->ofl_objs, ifl) == 0) return ((Sym_desc *)S_ERROR); } /* * Allocate a symbol structure and add it to the global symbol table. */ if ((sym = libld_calloc(sizeof (Sym), 1)) == 0) return ((Sym_desc *)S_ERROR); sym->st_info = ELF_ST_INFO(STB_GLOBAL, STT_NOTYPE); sym->st_shndx = SHN_UNDEF; DBG_CALL(Dbg_syms_process(ofl->ofl_lml, ifl)); if (sdp == NULL) { DBG_CALL(Dbg_syms_global(ofl->ofl_lml, 0, name)); if ((sdp = ld_sym_enter(name, sym, hash, ifl, ofl, 0, SHN_UNDEF, 0, 0, &where)) == (Sym_desc *)S_ERROR) return ((Sym_desc *)S_ERROR); } else if (ld_sym_resolve(sdp, sym, ifl, ofl, 0, SHN_UNDEF, 0) == S_ERROR) return ((Sym_desc *)S_ERROR); sdp->sd_flags &= ~FLG_SY_CLEAN; sdp->sd_flags |= FLG_SY_CMDREF; return (sdp); }