/* * 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 (c) 1991, 2010, Oracle and/or its affiliates. All rights reserved. */ /* * Symbol table resolution */ #define ELF_TARGET_AMD64 #include #include #include "msg.h" #include "_libld.h" /* * Categorize the symbol types that are applicable to the resolution process. */ typedef enum { SYM_DEFINED, /* Defined symbol (SHN_ABS or shndx != 0) */ SYM_UNDEFINED, /* Undefined symbol (SHN_UNDEF) */ SYM_TENTATIVE, /* Tentative symbol (SHN_COMMON) */ SYM_NUM /* the number of symbol types */ } Symtype; /* * Do nothing. */ /* ARGSUSED0 */ static void sym_null(Sym_desc *sdp, Sym *nsym, Ifl_desc *ifl, Ofl_desc *ofl, int ndx, Word nshndx, sd_flag_t nsdflags) { } static void sym_visibility_diag(Error err, Sym_desc *sdp, Sym *osym, Sym *nsym, Ifl_desc *ifl, Ofl_desc *ofl) { Conv_inv_buf_t inv_obuf, inv_nbuf; /* Warnings are only issued when -z verbose is specified */ if (!(ofl->ofl_flags & FLG_OF_VERBOSE) && (err != ERR_FATAL)) return; ld_eprintf(ofl, err, MSG_INTL(MSG_SYM_CONFVIS), demangle(sdp->sd_name)); ld_eprintf(ofl, ERR_NONE, MSG_INTL(MSG_SYM_VISTYPES), sdp->sd_file->ifl_name, conv_sym_other(osym->st_other, &inv_obuf), ifl->ifl_name, conv_sym_other(nsym->st_other, &inv_nbuf)); if (err != ERR_FATAL) ld_eprintf(ofl, ERR_NONE, MSG_INTL(MSG_SYM_DEFTAKEN), ifl->ifl_name); } /* * STV_VISIBILITY rules for STV_DEFAULT/INTERNAL/HIDDEN/PROTECTED say that the * most restrictive visibility value should be taken. The precedence is: * * (most restrictive) INTERNAL -> HIDDEN -> PROTECTED -> DEFAULT (least) * * The STV_EXPORT and STV_SINGLETON visibilities are slightly different, in that * the visibility must remain global and can not be reduced in any way. * * Resolution of different visibilities between two relocatable objects can * take the following actions: * * i. if applicable, the most restrictive action is silently taken. * ii. if a mapfile visibility definition competes with a more restrictive * relocatable object definition, then a warning is generated, but the * the more restrictive visibility is taken. * iii. in the case of conflicts with an EXPORTED or SINGLETON symbol with * any type of visibility between relocatable objects, the combination * is deemed fatal. * * new visibility * D I H P X S * ------------------------------------------------------------ * D | D I(mw) H(mw) P X S * original I | I I I I X(mw/of) S(mw/of) * visibility H | H I(mw) H H X(mw/of) S(mw/of) * P | P I(mw) H(mw) P X(mw/of) S(mw/of) * X | X I(mw/of) H(mw/of) P(mw/of) X S * S | S I(mw/of) H(mw/of) P(mw/of) S S * where: * * mw - mapfile warning: if the original symbol originates from a mapfile * then warn the user that their scope definition is being overridden. * of - object definitions are fatal: any combination of relocatable object * visibilities that conflict with a SINGLETON and EXPORTED are fatal. * * Note, an eliminate symbol (STV_ELIMINATE) is treated as hidden (STV_HIDDEN) * for processing through this state table. */ static Half sym_visibility(Sym_desc *sdp, Sym *nsym, Ifl_desc *ifl, Ofl_desc *ofl) { Sym *osym = sdp->sd_sym; uchar_t wovis, ovis; uchar_t wnvis, nvis; wovis = ovis = ELF_ST_VISIBILITY(osym->st_other); wnvis = nvis = ELF_ST_VISIBILITY(nsym->st_other); /* * If the original visibilities are eliminate, assign them hidden for * the state table processing. The original visibility, rather than * the working visibility, will be returned to the caller. */ if (wovis == STV_ELIMINATE) wovis = STV_HIDDEN; if (wnvis == STV_ELIMINATE) wnvis = STV_HIDDEN; /* * The most complex visibility resolution is between two relocatable * objects. However, in the case of SINGLETONS we also want to catch * any singleton definitions within shared objects. Relocatable objects * that bind to these symbols inherit the singleton visibility as this * efficiently triggers ld.so.1 into carrying out the appropriate * runtime symbol search. Any other resolution between a relocatable * object and a shared object will retain the relocatable objects * visibility. */ if ((sdp->sd_ref == REF_REL_NEED) && (ifl->ifl_ehdr->e_type == ET_DYN)) { if ((sdp->sd_sym->st_shndx == SHN_UNDEF) && (nsym->st_shndx != SHN_UNDEF) && (wnvis == STV_SINGLETON)) return (STV_SINGLETON); else return (ovis); } if ((sdp->sd_ref != REF_REL_NEED) && (ifl->ifl_ehdr->e_type == ET_REL)) { if ((sdp->sd_sym->st_shndx != SHN_UNDEF) && (nsym->st_shndx == SHN_UNDEF) && (wovis == STV_SINGLETON)) return (STV_SINGLETON); else return (nvis); } /* * If the visibilities are the same, we're done. If the working * visibilities differ from the original, then one must have been * STV_HIDDEN and the other STV_ELIMINATE. */ if (wovis == wnvis) { if (ovis == nvis) return (nvis); else return (STV_ELIMINATE); } /* * An EXPORTED symbol or SINGLETON symbol can not be demoted, any * conflicting visibility from another object is fatal. A conflicting * visibility from a mapfile produces a warning, as the mapfile * definition can be overridden. */ if ((wnvis == STV_EXPORTED) || (wnvis == STV_SINGLETON)) { if ((wovis != STV_DEFAULT) && (wovis != STV_EXPORTED) && (wovis != STV_SINGLETON)) { if (sdp->sd_flags & FLG_SY_MAPFILE) { sym_visibility_diag(ERR_WARNING, sdp, osym, nsym, ifl, ofl); } else { sym_visibility_diag(ERR_FATAL, sdp, osym, nsym, ifl, ofl); } } return (nvis); } if (wovis == STV_SINGLETON) { if ((wnvis == STV_EXPORTED) || (wnvis == STV_DEFAULT)) return (STV_SINGLETON); if (sdp->sd_flags & FLG_SY_MAPFILE) { sym_visibility_diag(ERR_WARNING, sdp, osym, nsym, ifl, ofl); } else { sym_visibility_diag(ERR_FATAL, sdp, osym, nsym, ifl, ofl); } return (nvis); } if (wovis == STV_EXPORTED) { if (wnvis == STV_SINGLETON) return (STV_SINGLETON); if (wnvis == STV_DEFAULT) return (STV_EXPORTED); if (sdp->sd_flags & FLG_SY_MAPFILE) { sym_visibility_diag(ERR_WARNING, sdp, osym, nsym, ifl, ofl); } else { sym_visibility_diag(ERR_FATAL, sdp, osym, nsym, ifl, ofl); } return (nvis); } /* * Now that symbols with the same visibility, and all instances of * SINGLETON's have been dealt with, we're left with visibilities that * differ, but can be dealt with in the order of how restrictive the * visibilities are. When a differing visibility originates from a * mapfile definition, produces a warning, as the mapfile definition * can be overridden by the relocatable object. */ if ((wnvis == STV_INTERNAL) || (wovis == STV_INTERNAL)) { if ((wnvis == STV_INTERNAL) && (sdp->sd_flags & FLG_SY_MAPFILE)) { sym_visibility_diag(ERR_WARNING, sdp, osym, nsym, ifl, ofl); } return (STV_INTERNAL); } else if ((wnvis == STV_HIDDEN) || (wovis == STV_HIDDEN)) { if ((wnvis == STV_HIDDEN) && (sdp->sd_flags & FLG_SY_MAPFILE)) { sym_visibility_diag(ERR_WARNING, sdp, osym, nsym, ifl, ofl); } /* * In the case of STV_ELIMINATE and STV_HIDDEN, the working * visibility can differ from the original visibility, so make * sure to return the original visibility. */ if ((ovis == STV_ELIMINATE) || (nvis == STV_ELIMINATE)) return (STV_ELIMINATE); else return (STV_HIDDEN); } else if ((wnvis == STV_PROTECTED) || (wovis == STV_PROTECTED)) return (STV_PROTECTED); return (STV_DEFAULT); } /* * Check if two symbols types are compatible */ /*ARGSUSED4*/ static void sym_typecheck(Sym_desc *sdp, Sym *nsym, Ifl_desc *ifl, Ofl_desc *ofl, int ndx, Word nshndx, sd_flag_t nsdflags) { uchar_t otype = ELF_ST_TYPE(sdp->sd_sym->st_info); uchar_t ntype = ELF_ST_TYPE(nsym->st_info); Conv_inv_buf_t inv_buf1, inv_buf2; /* * Perform any machine specific type checking. */ if ((ld_targ.t_ms.ms_mach_sym_typecheck != NULL) && (*ld_targ.t_ms.ms_mach_sym_typecheck)(sdp, nsym, ifl, ofl)) return; /* * NOTYPE's can be combined with other types, only give an error if * combining two differing types without NOTYPE. */ if ((otype == ntype) || (otype == STT_NOTYPE) || (ntype == STT_NOTYPE)) return; ld_eprintf(ofl, ERR_WARNING, MSG_INTL(MSG_SYM_DIFFTYPE), demangle(sdp->sd_name)); ld_eprintf(ofl, ERR_NONE, MSG_INTL(MSG_SYM_FILETYPES), sdp->sd_file->ifl_name, conv_sym_info_type(ofl->ofl_dehdr->e_machine, otype, 0, &inv_buf1), ifl->ifl_name, conv_sym_info_type(ofl->ofl_dehdr->e_machine, ntype, 0, &inv_buf2)); } /*ARGSUSED4*/ static void sym_mach_check(Sym_desc *sdp, Sym *nsym, Ifl_desc *ifl, Ofl_desc *ofl, int ndx, Word nshndx, sd_flag_t nsdflags) { /* * Perform any machine specific type checking. */ if (ld_targ.t_ms.ms_mach_sym_typecheck != NULL) (void) (*ld_targ.t_ms.ms_mach_sym_typecheck)(sdp, nsym, ifl, ofl); } /* * Promote the symbols reference. */ static void /* ARGSUSED4 */ sym_promote(Sym_desc *sdp, Sym *nsym, Ifl_desc *ifl, Ofl_desc *ofl, int ndx, Word nshndx, sd_flag_t nsdflags) { Word shndx = nsym->st_shndx; sym_typecheck(sdp, nsym, ifl, ofl, ndx, nshndx, nsdflags); /* * If the old symbol is from a shared object and the new symbol is a * reference from a relocatable object, promote the old symbols * reference. */ if ((sdp->sd_ref == REF_DYN_SEEN) && (ifl->ifl_ehdr->e_type == ET_REL)) { sdp->sd_ref = REF_DYN_NEED; /* * If this is an undefined symbol it must be a relocatable * object overriding a shared object. In this case also * override the reference name so that any undefined symbol * diagnostics will refer to the relocatable object name. */ if (shndx == SHN_UNDEF) sdp->sd_aux->sa_rfile = ifl->ifl_name; /* * If this symbol is an undefined, or common, determine whether * it is a global or weak reference (see build_osym(), where * REF_DYN_NEED definitions are returned back to undefines). */ if (((shndx == SHN_UNDEF) || ((nsdflags & FLG_SY_SPECSEC) && (shndx == SHN_COMMON))) && (ELF_ST_BIND(nsym->st_info) == STB_GLOBAL)) sdp->sd_flags |= FLG_SY_GLOBREF; } } /* * Override a symbol. */ static void sym_override(Sym_desc *sdp, Sym *nsym, Ifl_desc *ifl, Ofl_desc *ofl, int ndx, Word nshndx, sd_flag_t nsdflags) { Sym *osym = sdp->sd_sym; Word link; /* * In the case of a WEAK UNDEF symbol don't let a symbol from an * unavailable object override the symbol definition. This is because * this symbol *may* not be present in a future object and by promoting * this symbol we are actually causing bindings (PLTS) to be formed * to this symbol. Instead let the 'generic' weak binding take place. */ if ((ELF_ST_BIND(osym->st_info) == STB_WEAK) && (sdp->sd_sym->st_shndx == SHN_UNDEF) && ((ifl->ifl_flags & FLG_IF_NEEDED) == 0)) return; sym_typecheck(sdp, nsym, ifl, ofl, ndx, nshndx, nsdflags); /* * This symbol has already been compared to an SO definition, * as per the runtime behavior, ignore extra definitions. */ if ((sdp->sd_flags & FLG_SY_SOFOUND) && (ifl->ifl_ehdr->e_type == ET_DYN)) return; /* * Mark the symbol as available and copy the new symbols contents. */ sdp->sd_flags &= ~FLG_SY_NOTAVAIL; *osym = *nsym; sdp->sd_shndx = nshndx; sdp->sd_flags &= ~FLG_SY_SPECSEC; sdp->sd_flags |= (nsdflags & (FLG_SY_SPECSEC | FLG_SY_TENTSYM)); /* * If the new symbol has PROTECTED visibility, mark it. If a PROTECTED * symbol is copy relocated, a warning message will be printed. See * reloc_exec(). */ if (ELF_ST_VISIBILITY(nsym->st_other) == STV_PROTECTED) sdp->sd_flags |= FLG_SY_PROT; else sdp->sd_flags &= ~FLG_SY_PROT; /* * Establish the symbols reference. If the new symbol originates from a * relocatable object then this reference becomes needed, otherwise * the new symbol must be from a shared object. In this case only * promote the symbol to needed if we presently have a reference from a * relocatable object. */ if (ifl->ifl_ehdr->e_type == ET_REL) { sdp->sd_ref = REF_REL_NEED; if (nsym->st_shndx == SHN_UNDEF) { /* * If this is an undefined symbol, then we can only be * attempting to override an existing undefined symbol. * The original symbol is either: * * - a mapfile definition * - a previous relocatable object whose visibility * or type should be overridden by this new symbol * - a previous shared object * * If the original undefined symbol stems from a mapfile * then don't alter the reference file name. Should we * end up with some form of 'undefined' symbol error, * the characteristics of that error are most likely to * have originated from a mapfile. * * Otherwise, update the reference file name to indicate * this symbol. */ if ((sdp->sd_flags & FLG_SY_MAPREF) == 0) sdp->sd_aux->sa_rfile = ifl->ifl_name; } else { /* * 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_flags & (FLG_SY_PROTECT | FLG_SY_DIR)) == 0)) sdp->sd_flags |= FLG_SY_NDIR; } /* * If this symbol is an undefined, or common, determine whether * it is a global or weak reference (see build_osym(), where * REF_DYN_NEED definitions are returned back to undefines). */ if (((nsym->st_shndx == SHN_UNDEF) || ((nsdflags & FLG_SY_SPECSEC) && (nsym->st_shndx == SHN_COMMON))) && (ELF_ST_BIND(nsym->st_info) == STB_GLOBAL)) sdp->sd_flags |= FLG_SY_GLOBREF; else sdp->sd_flags &= ~FLG_SY_GLOBREF; } else { if (sdp->sd_ref == REF_REL_NEED) sdp->sd_ref = REF_DYN_NEED; /* * Determine the symbols availability. 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]; sdp->sd_aux->sa_dverndx = vndx; vip = &ifl->ifl_verndx[vndx]; if (!(vip->vi_flags & FLG_VER_AVAIL)) { sdp->sd_flags |= FLG_SY_NOTAVAIL; /* * If this is the first occurrence of an * unavailable symbol record it for possible * use in later error diagnostics * (see sym_undef). */ if (!(sdp->sd_aux->sa_vfile)) sdp->sd_aux->sa_vfile = ifl->ifl_name; } } if (!(ifl->ifl_flags & FLG_IF_NEEDED)) sdp->sd_flags |= FLG_SY_NOTAVAIL; } /* * Make sure any symbol association maintained by the original symbol * is cleared and then update the symbols file reference. */ if ((link = sdp->sd_aux->sa_linkndx) != 0) { Sym_desc * _sdp; _sdp = sdp->sd_file->ifl_oldndx[link]; _sdp->sd_aux->sa_linkndx = 0; sdp->sd_aux->sa_linkndx = 0; } sdp->sd_file = ifl; /* * Update the input section descriptor to that of the new input file */ if (((nsdflags & FLG_SY_SPECSEC) == 0) && (nsym->st_shndx != SHN_UNDEF) && ((sdp->sd_isc = ifl->ifl_isdesc[nshndx]) == NULL)) ld_eprintf(ofl, ERR_FATAL, MSG_INTL(MSG_SYM_NOSECDEF), demangle(sdp->sd_name), ifl->ifl_name); } /* * Resolve two undefines (only called for two relocatable objects). */ static void sym_twoundefs(Sym_desc *sdp, Sym *nsym, Ifl_desc *ifl, Ofl_desc *ofl, int ndx, Word nshndx, sd_flag_t nsdflags) { Sym *osym = sdp->sd_sym; uchar_t obind = ELF_ST_BIND(osym->st_info); uchar_t otype = ELF_ST_TYPE(osym->st_info); uchar_t nbind = ELF_ST_BIND(nsym->st_info); uchar_t ntype = ELF_ST_TYPE(nsym->st_info); /* * If two relocatable objects define a weak and non-weak undefined * reference, take the non-weak definition. * * -- or -- * * If two relocatable objects define a NOTYPE & another, then * take the other. */ if (((obind == STB_WEAK) && (nbind != STB_WEAK)) || (otype == STT_NOTYPE) && (ntype != STT_NOTYPE)) { sym_override(sdp, nsym, ifl, ofl, ndx, nshndx, nsdflags); return; } sym_typecheck(sdp, nsym, ifl, ofl, ndx, nshndx, nsdflags); } /* * Resolve two real definitions. */ static void sym_tworeals(Sym_desc *sdp, Sym *nsym, Ifl_desc *ifl, Ofl_desc *ofl, int ndx, Word nshndx, sd_flag_t nsdflags) { Conv_inv_buf_t inv_buf1, inv_buf2; Sym *osym = sdp->sd_sym; uchar_t otype = ELF_ST_TYPE(osym->st_info); uchar_t obind = ELF_ST_BIND(osym->st_info); uchar_t ntype = ELF_ST_TYPE(nsym->st_info); uchar_t nbind = ELF_ST_BIND(nsym->st_info); Half ofile = sdp->sd_file->ifl_ehdr->e_type; Half nfile = ifl->ifl_ehdr->e_type; int warn = 0; /* * If both definitions are from relocatable objects, and have non-weak * binding then this is a fatal condition. */ if ((ofile == ET_REL) && (nfile == ET_REL) && (obind != STB_WEAK) && (nbind != STB_WEAK) && (!(ofl->ofl_flags & FLG_OF_MULDEFS))) { ld_eprintf(ofl, ERR_FATAL, MSG_INTL(MSG_SYM_MULDEF), demangle(sdp->sd_name)); ld_eprintf(ofl, ERR_NONE, MSG_INTL(MSG_SYM_FILETYPES), sdp->sd_file->ifl_name, conv_sym_info_type(ofl->ofl_dehdr->e_machine, otype, 0, &inv_buf1), ifl->ifl_name, conv_sym_info_type(ofl->ofl_dehdr->e_machine, ntype, 0, &inv_buf2)); return; } /* * Perform any machine specific type checking. */ if ((ld_targ.t_ms.ms_mach_sym_typecheck != NULL) && (*ld_targ.t_ms.ms_mach_sym_typecheck)(sdp, nsym, ifl, ofl)) return; /* * Check the symbols type and size. */ if (otype != ntype) { ld_eprintf(ofl, ERR_WARNING, MSG_INTL(MSG_SYM_DIFFTYPE), demangle(sdp->sd_name)); ld_eprintf(ofl, ERR_NONE, MSG_INTL(MSG_SYM_FILETYPES), sdp->sd_file->ifl_name, conv_sym_info_type(ofl->ofl_dehdr->e_machine, otype, 0, &inv_buf1), ifl->ifl_name, conv_sym_info_type(ofl->ofl_dehdr->e_machine, ntype, 0, &inv_buf2)); warn++; } else if ((otype == STT_OBJECT) && (osym->st_size != nsym->st_size)) { if (!(ofl->ofl_flags & FLG_OF_NOWARN)) { ld_eprintf(ofl, ERR_WARNING, MSG_INTL(MSG_SYM_DIFFATTR), demangle(sdp->sd_name), MSG_INTL(MSG_STR_SIZES), sdp->sd_file->ifl_name, EC_XWORD(osym->st_size), ifl->ifl_name, EC_XWORD(nsym->st_size)); warn++; } } /* * Having provided the user with any necessary warnings, take the * appropriate symbol: * * - if one symbol is from a shared object and the other is from a * relocatable object, take the relocatable objects symbol (the * run-time linker is always going to find the relocatable object * symbol regardless of the binding), else * * - if both symbols are from relocatable objects and one symbol is * weak take the non-weak symbol (two non-weak symbols would have * generated the fatal error condition above unless -z muldefs is * in effect), else * * - take the first symbol definition encountered. */ if ((sdp->sd_flags & FLG_SY_SOFOUND) && (nfile == ET_DYN)) { if (warn) ld_eprintf(ofl, ERR_NONE, MSG_INTL(MSG_SYM_DEFTAKEN), sdp->sd_file->ifl_name); return; } else if ((nfile == ET_REL) && ((ofile == ET_DYN) || ((obind == STB_WEAK) && (nbind != STB_WEAK)))) { if (warn) ld_eprintf(ofl, ERR_NONE, MSG_INTL(MSG_SYM_DEFTAKEN), ifl->ifl_name); sym_override(sdp, nsym, ifl, ofl, ndx, nshndx, nsdflags); return; } else { if (warn) ld_eprintf(ofl, ERR_NONE, MSG_INTL(MSG_SYM_DEFTAKEN), sdp->sd_file->ifl_name); sym_promote(sdp, nsym, ifl, ofl, ndx, nshndx, nsdflags); return; } } /* * Resolve a real and tentative definition. */ static void sym_realtent(Sym_desc *sdp, Sym *nsym, Ifl_desc *ifl, Ofl_desc *ofl, int ndx, Word nshndx, sd_flag_t nsdflags) { Conv_inv_buf_t inv_buf1, inv_buf2; Sym *osym = sdp->sd_sym; uchar_t otype = ELF_ST_TYPE(osym->st_info); uchar_t obind = ELF_ST_BIND(osym->st_info); uchar_t ntype = ELF_ST_TYPE(nsym->st_info); uchar_t nbind = ELF_ST_BIND(nsym->st_info); Boolean otent = FALSE, ntent = FALSE; Half ofile = sdp->sd_file->ifl_ehdr->e_type; Half nfile = ifl->ifl_ehdr->e_type; int warn = 0; uchar_t ovis = ELF_ST_VISIBILITY(osym->st_other); uchar_t nvis = ELF_ST_VISIBILITY(nsym->st_other); /* * Special rules for functions. * * - If both definitions are from relocatable objects, have the same * binding (ie. two weaks or two non-weaks), and the real * definition is a function (the other must be tentative), treat * this as a multiply defined symbol error, else * * - if the real symbol definition is a function within a shared * library and the tentative symbol is a relocatable object, and * the tentative is not weak and the function real, then retain the * tentative definition. */ if ((ofile == ET_REL) && (nfile == ET_REL) && (obind == nbind) && ((otype == STT_FUNC) || (ntype == STT_FUNC))) { if (ofl->ofl_flags & FLG_OF_MULDEFS) { ld_eprintf(ofl, ERR_WARNING, MSG_INTL(MSG_SYM_DIFFTYPE), demangle(sdp->sd_name)); sym_promote(sdp, nsym, ifl, ofl, ndx, nshndx, nsdflags); } else { ld_eprintf(ofl, ERR_FATAL, MSG_INTL(MSG_SYM_MULDEF), demangle(sdp->sd_name)); } ld_eprintf(ofl, ERR_NONE, MSG_INTL(MSG_SYM_FILETYPES), sdp->sd_file->ifl_name, conv_sym_info_type(ofl->ofl_dehdr->e_machine, otype, 0, &inv_buf1), ifl->ifl_name, conv_sym_info_type(ofl->ofl_dehdr->e_machine, ntype, 0, &inv_buf2)); return; } else if (ofile != nfile) { if ((ofile == ET_DYN) && (otype == STT_FUNC)) { if ((otype != STB_WEAK) && (ntype == STB_WEAK)) return; else { sym_override(sdp, nsym, ifl, ofl, ndx, nshndx, nsdflags); return; } } if ((nfile == ET_DYN) && (ntype == STT_FUNC)) { if ((ntype != STB_WEAK) && (otype == STB_WEAK)) { sym_override(sdp, nsym, ifl, ofl, ndx, nshndx, nsdflags); return; } else return; } } if (sdp->sd_flags & FLG_SY_TENTSYM) otent = TRUE; if (nsdflags & FLG_SY_TENTSYM) ntent = TRUE; /* * Check the symbols type and size. */ if (otype != ntype) { ld_eprintf(ofl, ERR_WARNING, MSG_INTL(MSG_SYM_DIFFTYPE), demangle(sdp->sd_name)); ld_eprintf(ofl, ERR_NONE, MSG_INTL(MSG_SYM_FILETYPES), sdp->sd_file->ifl_name, conv_sym_info_type(ofl->ofl_dehdr->e_machine, otype, 0, &inv_buf1), ifl->ifl_name, conv_sym_info_type(ofl->ofl_dehdr->e_machine, ntype, 0, &inv_buf2)); warn++; } else if (osym->st_size != nsym->st_size) { /* * If both definitions are from relocatable objects we have a * potential fatal error condition. If the tentative is larger * than the real definition treat this as a multiple definition. * Note that if only one symbol is weak, the non-weak will be * taken. */ if (((ofile == ET_REL) && (nfile == ET_REL) && (obind == nbind)) && ((otent && (osym->st_size > nsym->st_size)) || (ntent && (osym->st_size < nsym->st_size)))) { ld_eprintf(ofl, ERR_FATAL, MSG_INTL(MSG_SYM_DIFFATTR), demangle(sdp->sd_name), MSG_INTL(MSG_STR_SIZES), sdp->sd_file->ifl_name, EC_XWORD(osym->st_size), ifl->ifl_name, EC_XWORD(nsym->st_size)); ld_eprintf(ofl, ERR_NONE, MSG_INTL(MSG_SYM_TENTERR)); } else { if (!(ofl->ofl_flags & FLG_OF_NOWARN)) { ld_eprintf(ofl, ERR_WARNING, MSG_INTL(MSG_SYM_DIFFATTR), demangle(sdp->sd_name), MSG_INTL(MSG_STR_SIZES), sdp->sd_file->ifl_name, EC_XWORD(osym->st_size), ifl->ifl_name, EC_XWORD(nsym->st_size)); warn++; } } } /* * Having provided the user with any necessary warnings, take the * appropriate symbol: * * - if the original symbol is from relocatable file and it is * a protected tentative symbol, take the original one. * * - if the original symbol is from shared object and the new * symbol is a protected tentative symbol from a relocatable file, * take the new one. * * - if the original symbol is tentative, and providing the original * symbol isn't strong and the new symbol weak, take the real * symbol, else * * - if the original symbol is weak and the new tentative symbol is * strong take the new symbol. * * Refer to the System V ABI Page 4-27 for a description of the binding * requirements of tentative and weak symbols. */ if ((ofile == ET_REL) && (nfile == ET_DYN) && (otent == TRUE) && (ovis == STV_PROTECTED)) { return; } if ((ofile == ET_DYN) && (nfile == ET_REL) && (ntent == TRUE) && (nvis == STV_PROTECTED)) { sym_override(sdp, nsym, ifl, ofl, ndx, nshndx, nsdflags); return; } if ((sdp->sd_flags & FLG_SY_SOFOUND) && (nfile == ET_DYN)) { if (warn) ld_eprintf(ofl, ERR_NONE, MSG_INTL(MSG_SYM_DEFTAKEN), sdp->sd_file->ifl_name); return; } if (((otent) && (!((obind != STB_WEAK) && (nbind == STB_WEAK)))) || ((obind == STB_WEAK) && (nbind != STB_WEAK))) { if (warn) ld_eprintf(ofl, ERR_NONE, MSG_INTL(MSG_SYM_DEFTAKEN), ifl->ifl_name); sym_override(sdp, nsym, ifl, ofl, ndx, nshndx, nsdflags); return; } else { if (warn) ld_eprintf(ofl, ERR_NONE, MSG_INTL(MSG_SYM_DEFTAKEN), sdp->sd_file->ifl_name); sym_promote(sdp, nsym, ifl, ofl, ndx, nshndx, nsdflags); return; } } /* * Resolve two tentative symbols. */ static void sym_twotent(Sym_desc *sdp, Sym *nsym, Ifl_desc *ifl, Ofl_desc *ofl, int ndx, Word nshndx, sd_flag_t nsdflags) { Sym *osym = sdp->sd_sym; uchar_t obind = ELF_ST_BIND(osym->st_info); uchar_t nbind = ELF_ST_BIND(nsym->st_info); Half ofile = sdp->sd_file->ifl_ehdr->e_type; Half nfile = ifl->ifl_ehdr->e_type; size_t size = 0; Xword value = 0; #if defined(_ELF64) if (ld_targ.t_m.m_mach == EM_AMD64) { /* * If the original and new symbols are both COMMON, but of * a different size model, take the small one. */ if ((sdp->sd_sym->st_shndx == SHN_COMMON) && (nsym->st_shndx == SHN_X86_64_LCOMMON)) { /* * Take the original symbol. */ return; } else if ((sdp->sd_sym->st_shndx == SHN_X86_64_LCOMMON) && (nsym->st_shndx == SHN_COMMON)) { /* * Take the new symbol. */ sym_override(sdp, nsym, ifl, ofl, ndx, nshndx, nsdflags); return; } } #endif /* * Check the alignment of the symbols. This can only be tested for if * the symbols are not real definitions to a SHT_NOBITS section (ie. * they were originally tentative), as in this case the symbol would * have a displacement value rather than an alignment. In other words * we can only test this for two relocatable objects. */ /* BEGIN CSTYLED */ if ((osym->st_value != nsym->st_value) && ((sdp->sd_flags & FLG_SY_SPECSEC) && (sdp->sd_sym->st_shndx == SHN_COMMON) && (nsdflags & FLG_SY_SPECSEC) && #if defined(_ELF64) (nsym->st_shndx == SHN_COMMON)) || ((ld_targ.t_m.m_mach == EM_AMD64) && (sdp->sd_flags & FLG_SY_SPECSEC) && (sdp->sd_sym->st_shndx == SHN_X86_64_LCOMMON) && (nsdflags & FLG_SY_SPECSEC) && (nsym->st_shndx == SHN_X86_64_LCOMMON))) { #else (nsym->st_shndx == SHN_COMMON))) { #endif /* END CSTYLED */ const char *emsg = MSG_INTL(MSG_SYM_DEFTAKEN); const char *file; Xword salign; Xword balign; uint_t alignscompliment; if (osym->st_value < nsym->st_value) { salign = osym->st_value; balign = nsym->st_value; } else { salign = nsym->st_value; balign = osym->st_value; } /* * If the smaller alignment fits smoothly into the * larger alignment - we take it with no warning. */ if (S_ALIGN(balign, salign) == balign) alignscompliment = 1; else alignscompliment = 0; if (!(ofl->ofl_flags & FLG_OF_NOWARN) && !alignscompliment) ld_eprintf(ofl, ERR_WARNING, MSG_INTL(MSG_SYM_DIFFATTR), demangle(sdp->sd_name), MSG_INTL(MSG_STR_ALIGNMENTS), sdp->sd_file->ifl_name, EC_XWORD(osym->st_value), ifl->ifl_name, EC_XWORD(nsym->st_value)); /* * Having provided the necessary warning indicate which * relocatable object we are going to take. * * - if one symbol is weak and the other is non-weak * take the non-weak symbol, else * * - take the largest alignment (as we still have to check * the symbols size simply save the largest value for * updating later). */ if ((obind == STB_WEAK) && (nbind != STB_WEAK)) file = ifl->ifl_name; else if (obind != nbind) file = sdp->sd_file->ifl_name; else { emsg = MSG_INTL(MSG_SYM_LARGER); value = balign; } if (!(ofl->ofl_flags & FLG_OF_NOWARN) && !alignscompliment) ld_eprintf(ofl, ERR_NONE, emsg, file); } /* * Check the size of the symbols. */ if (osym->st_size != nsym->st_size) { const char *emsg = MSG_INTL(MSG_SYM_DEFTAKEN); const char *file; if (!(ofl->ofl_flags & FLG_OF_NOWARN)) ld_eprintf(ofl, ERR_WARNING, MSG_INTL(MSG_SYM_DIFFATTR), demangle(sdp->sd_name), MSG_INTL(MSG_STR_SIZES), sdp->sd_file->ifl_name, EC_XWORD(osym->st_size), ifl->ifl_name, EC_XWORD(nsym->st_size)); /* * This symbol has already been compared to an SO definition, * as per the runtime behavior, ignore extra definitions. */ if ((sdp->sd_flags & FLG_SY_SOFOUND) && (nfile == ET_DYN)) { if (!(ofl->ofl_flags & FLG_OF_NOWARN)) ld_eprintf(ofl, ERR_NONE, emsg, sdp->sd_file->ifl_name); return; } /* * Having provided the necessary warning indicate what course * of action we are going to take. * * - if the file types differ, take the relocatable object * and apply the largest symbol size, else * - if one symbol is weak and the other is non-weak, take * the non-weak symbol, else * - simply take the largest symbol reference. */ if (nfile != ofile) { if (nfile == ET_REL) { file = ifl->ifl_name; if (osym->st_size > nsym->st_size) { size = (size_t)osym->st_size; emsg = MSG_INTL(MSG_SYM_DEFUPDATE); } sym_override(sdp, nsym, ifl, ofl, ndx, nshndx, nsdflags); } else { file = sdp->sd_file->ifl_name; if (osym->st_size < nsym->st_size) { size = (size_t)nsym->st_size; emsg = MSG_INTL(MSG_SYM_DEFUPDATE); } sym_promote(sdp, nsym, ifl, ofl, ndx, nshndx, nsdflags); } } else if (obind != nbind) { if ((obind == STB_WEAK) && (nbind != STB_WEAK)) { sym_override(sdp, nsym, ifl, ofl, ndx, nshndx, nsdflags); file = ifl->ifl_name; } else file = sdp->sd_file->ifl_name; } else { if (osym->st_size < nsym->st_size) { sym_override(sdp, nsym, ifl, ofl, ndx, nshndx, nsdflags); file = ifl->ifl_name; } else file = sdp->sd_file->ifl_name; } if (!(ofl->ofl_flags & FLG_OF_NOWARN)) ld_eprintf(ofl, ERR_NONE, emsg, file); if (size) sdp->sd_sym->st_size = (Xword)size; } else { /* * If the sizes are the same * * - if the file types differ, take the relocatable object, * else * * - if one symbol is weak and the other is non-weak, take * the non-weak symbol, else * * - take the first reference. */ if ((sdp->sd_flags & FLG_SY_SOFOUND) && (nfile == ET_DYN)) return; else if (((ofile != nfile) && (nfile == ET_REL)) || (((obind == STB_WEAK) && (nbind != STB_WEAK)) && (!((ofile != nfile) && (ofile == ET_REL))))) sym_override(sdp, nsym, ifl, ofl, ndx, nshndx, nsdflags); else sym_promote(sdp, nsym, ifl, ofl, ndx, nshndx, nsdflags); } /* * Enforce the largest alignment if necessary. */ if (value) sdp->sd_sym->st_value = value; } /* * Symbol resolution state table. `Action' describes the required * procedure to be called (if any). */ static void (*Action[REF_NUM * SYM_NUM * 2][SYM_NUM])(Sym_desc *, Sym *, Ifl_desc *, Ofl_desc *, int, Word, sd_flag_t) = { /* defined undef tent */ /* ET_REL ET_REL ET_REL */ /* 0 defined REF_DYN_SEEN */ sym_tworeals, sym_promote, sym_realtent, /* 1 undef REF_DYN_SEEN */ sym_override, sym_override, sym_override, /* 2 tent REF_DYN_SEEN */ sym_realtent, sym_promote, sym_twotent, /* 3 defined REF_DYN_NEED */ sym_tworeals, sym_typecheck, sym_realtent, /* 4 undef REF_DYN_NEED */ sym_override, sym_override, sym_override, /* 5 tent REF_DYN_NEED */ sym_realtent, sym_typecheck, sym_twotent, /* 6 defined REF_REL_NEED */ sym_tworeals, sym_typecheck, sym_realtent, /* 7 undef REF_REL_NEED */ sym_override, sym_twoundefs, sym_override, /* 8 tent REF_REL_NEED */ sym_realtent, sym_null, sym_twotent, /* defined undef tent */ /* ET_DYN ET_DYN ET_DYN */ /* 9 defined REF_DYN_SEEN */ sym_tworeals, sym_null, sym_realtent, /* 10 undef REF_DYN_SEEN */ sym_override, sym_mach_check, sym_override, /* 11 tent REF_DYN_SEEN */ sym_realtent, sym_null, sym_twotent, /* 12 defined REF_DYN_NEED */ sym_tworeals, sym_null, sym_realtent, /* 13 undef REF_DYN_NEED */ sym_override, sym_null, sym_override, /* 14 tent REF_DYN_NEED */ sym_realtent, sym_null, sym_twotent, /* 15 defined REF_REL_NEED */ sym_tworeals, sym_null, sym_realtent, /* 16 undef REF_REL_NEED */ sym_override, sym_mach_check, sym_override, /* 17 tent REF_REL_NEED */ sym_realtent, sym_null, sym_twotent }; uintptr_t ld_sym_resolve(Sym_desc *sdp, Sym *nsym, Ifl_desc *ifl, Ofl_desc *ofl, int ndx, Word nshndx, sd_flag_t nsdflags) { int row, column; /* State table coordinates */ Sym *osym = sdp->sd_sym; sd_flag_t osdflags = sdp->sd_flags; Is_desc *isp; Half vis = 0, nfile = ifl->ifl_ehdr->e_type; Half oref = sdp->sd_ref; /* * Determine the original symbols definition (defines row in Action[]). */ if (osdflags & FLG_SY_TENTSYM) row = SYM_TENTATIVE; else if ((sdp->sd_sym->st_shndx == SHN_UNDEF) || (sdp->sd_sym->st_shndx == SHN_SUNW_IGNORE)) row = SYM_UNDEFINED; else row = SYM_DEFINED; /* * If the input file is an implicit shared object then we don't need * to bind to any symbols within it other than to verify that any * undefined references will be closed (implicit shared objects are only * processed when no undefined symbols are required as a result of the * link-edit (see process_dynamic())). */ if ((nfile == ET_DYN) && !(ifl->ifl_flags & FLG_IF_NEEDED) && (row != SYM_UNDEFINED)) return (1); /* * Finish computing the Action[] row by applying the symbols reference * together with the input files type. */ row = row + (REF_NUM * sdp->sd_ref); if (nfile == ET_DYN) row += (REF_NUM * SYM_NUM); /* * If either the original or new symbol originates from a relocatable * object, determine the appropriate visibility for the resolved symbol. */ if ((oref == REF_REL_NEED) || (nfile == ET_REL)) vis = sym_visibility(sdp, nsym, ifl, ofl); /* * Determine the new symbols definition (defines column in Action[]). */ if ((nsdflags & FLG_SY_SPECSEC) && (nsym->st_shndx == SHN_COMMON)) { column = SYM_TENTATIVE; nsdflags |= FLG_SY_TENTSYM; #if defined(_ELF64) } else if ((ld_targ.t_m.m_mach == EM_AMD64) && (nsdflags & FLG_SY_SPECSEC) && (nsym->st_shndx == SHN_X86_64_LCOMMON)) { column = SYM_TENTATIVE; nsdflags |= FLG_SY_TENTSYM; #endif } else if ((nsym->st_shndx == SHN_UNDEF) || (nsym->st_shndx == SHN_SUNW_IGNORE)) { column = SYM_UNDEFINED; nshndx = SHN_UNDEF; } else { column = SYM_DEFINED; /* * If the new symbol is from a shared library and it is * associated with a SHT_NOBITS section then this symbol * originated from a tentative symbol. */ if (((nsdflags & FLG_SY_SPECSEC) == 0) && (nfile == ET_DYN)) { isp = ifl->ifl_isdesc[nshndx]; if (isp && (isp->is_shdr->sh_type == SHT_NOBITS)) { column = SYM_TENTATIVE; nsdflags |= FLG_SY_TENTSYM; } } } DBG_CALL(Dbg_syms_resolving(ofl, ndx, sdp->sd_name, row, column, osym, nsym, sdp, ifl)); /* * Record the input filename on the defined files list for possible * later diagnostics. The `sa_dfiles' list is used to maintain the list * of shared objects that define the same symbol. This list is only * generated when the -m option is in effect and is used to list * multiple (interposed) definitions of a symbol (refer to ldmap_out()). */ if ((ofl->ofl_flags & FLG_OF_GENMAP) && (nsym->st_shndx != SHN_UNDEF) && ((nsdflags & FLG_SY_SPECSEC) == 0)) if (aplist_append(&sdp->sd_aux->sa_dfiles, ifl->ifl_name, AL_CNT_SDP_DFILES) == NULL) return (S_ERROR); /* * Perform the required resolution. */ Action[row][column](sdp, nsym, ifl, ofl, ndx, nshndx, nsdflags); /* * Apply any visibility requirements. If a SINGLETON has been * established, make sure no symbol reduction indicators remain * associated with the symbol, and indicate that the symbol can not * be directly bound to. */ if ((oref == REF_REL_NEED) || (nfile == ET_REL)) { if ((vis == STV_EXPORTED) || (vis == STV_SINGLETON)) { sdp->sd_flags &= ~MSK_SY_LOCAL; if (vis == STV_EXPORTED) sdp->sd_flags |= FLG_SY_EXPORT; else { sdp->sd_flags |= (FLG_SY_NDIR | FLG_SY_SINGLE); if (sdp->sd_ref == REF_REL_NEED) { ofl->ofl_flags1 |= (FLG_OF1_NDIRECT | FLG_OF1_NGLBDIR); } } } else if (vis == STV_PROTECTED) { sdp->sd_flags |= FLG_SY_PROTECT; } else if ((vis == STV_INTERNAL) || (vis == STV_HIDDEN)) { sdp->sd_flags |= FLG_SY_HIDDEN; } else if (vis == STV_ELIMINATE) { sdp->sd_flags |= (FLG_SY_HIDDEN | FLG_SY_ELIM); } sdp->sd_sym->st_other = (sdp->sd_sym->st_other & ~MSK_SYM_VISIBILITY) | vis; } /* * If the symbol has been resolved to the new input file, and this is * a versioned relocatable object, then the version information of the * new symbol must be promoted to the versioning of the output file. */ if ((sdp->sd_file == ifl) && (nfile == ET_REL) && (ifl->ifl_versym) && (nsym->st_shndx != SHN_UNDEF)) ld_vers_promote(sdp, ndx, ifl, ofl); /* * Determine whether a mapfile reference has been satisfied. Mapfile * symbol references augment symbols that should be contributed from * the relocatable objects used to build the output image. If a * relocatable object doesn't provide one of the mapfile symbol * references then somethings amiss, and will be flagged during symbol * validation. */ if ((nfile == ET_REL) && ((sdp->sd_flags & (FLG_SY_MAPREF | FLG_SY_MAPUSED)) == FLG_SY_MAPREF)) { /* * Extern and parent references are satisfied by references from * a relocatable object. Note that we let *any* symbol type * satisfy this reference, to be as flexible as possible with * user written mapfiles. It could be questionable, for * example, if what a user expects to be an extern reference is * actually found to be a definition in a relocatable object. * * Any other mapfile reference (typically for versioning * information) simply augments a relocatables definition. */ if ((sdp->sd_flags & (FLG_SY_EXTERN | FLG_SY_PARENT)) || ((sdp->sd_sym->st_shndx != SHN_UNDEF) && (sdp->sd_ref == REF_REL_NEED))) sdp->sd_flags |= FLG_SY_MAPUSED; } /* * Make sure any special symbol requirements are carried over. */ if ((osdflags & FLG_SY_CAP) || (nsdflags & FLG_SY_CAP)) sdp->sd_flags |= FLG_SY_CAP; DBG_CALL(Dbg_syms_resolved(ofl, sdp)); return (1); }