/* $NetBSD: mdreloc.c,v 1.72 2024/08/03 21:59:58 riastradh Exp $ */ /*- * Copyright (c) 2000 Eduardo Horvath. * Copyright (c) 1999, 2002 The NetBSD Foundation, Inc. * All rights reserved. * * This code is derived from software contributed to The NetBSD Foundation * by Paul Kranenburg and by Charles M. Hannum. * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions * are met: * 1. Redistributions of source code must retain the above copyright * notice, this list of conditions and the following disclaimer. * 2. Redistributions in binary form must reproduce the above copyright * notice, this list of conditions and the following disclaimer in the * documentation and/or other materials provided with the distribution. * * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE * POSSIBILITY OF SUCH DAMAGE. */ /* * SPARC ELF relocations. * * Reference: * * SPARC Compliance Definition 2.4.1 * http://sparc.org/wp-content/uploads/2014/01/SCD.2.4.1.pdf.gz */ #include #ifndef lint __RCSID("$NetBSD: mdreloc.c,v 1.72 2024/08/03 21:59:58 riastradh Exp $"); #endif /* not lint */ #include #include #include #include #include #include #include "rtldenv.h" #include "debug.h" #include "rtld.h" /* * The following table holds for each relocation type: * - the width in bits of the memory location the relocation * applies to (not currently used) * - the number of bits the relocation value must be shifted to the * right (i.e. discard least significant bits) to fit into * the appropriate field in the instruction word. * - flags indicating whether * * the relocation involves a symbol * * the relocation is relative to the current position * * the relocation is for a GOT entry * * the relocation is relative to the load address * */ #define _RF_S 0x80000000 /* Resolve symbol */ #define _RF_A 0x40000000 /* Use addend */ #define _RF_P 0x20000000 /* Location relative */ #define _RF_G 0x10000000 /* GOT offset */ #define _RF_B 0x08000000 /* Load address relative */ #define _RF_U 0x04000000 /* Unaligned */ #define _RF_SZ(s) (((s) & 0xff) << 8) /* memory target size */ #define _RF_RS(s) ( (s) & 0xff) /* right shift */ static const int reloc_target_flags[R_TYPE(TLS_TPOFF64)+1] = { 0, /* NONE */ _RF_S|_RF_A| _RF_SZ(8) | _RF_RS(0), /* RELOC_8 */ _RF_S|_RF_A| _RF_SZ(16) | _RF_RS(0), /* RELOC_16 */ _RF_S|_RF_A| _RF_SZ(32) | _RF_RS(0), /* RELOC_32 */ _RF_S|_RF_A|_RF_P| _RF_SZ(8) | _RF_RS(0), /* DISP_8 */ _RF_S|_RF_A|_RF_P| _RF_SZ(16) | _RF_RS(0), /* DISP_16 */ _RF_S|_RF_A|_RF_P| _RF_SZ(32) | _RF_RS(0), /* DISP_32 */ _RF_S|_RF_A|_RF_P| _RF_SZ(32) | _RF_RS(2), /* WDISP_30 */ _RF_S|_RF_A|_RF_P| _RF_SZ(32) | _RF_RS(2), /* WDISP_22 */ _RF_S|_RF_A| _RF_SZ(32) | _RF_RS(10), /* HI22 */ _RF_S|_RF_A| _RF_SZ(32) | _RF_RS(0), /* 22 */ _RF_S|_RF_A| _RF_SZ(32) | _RF_RS(0), /* 13 */ _RF_S|_RF_A| _RF_SZ(32) | _RF_RS(0), /* LO10 */ _RF_G| _RF_SZ(32) | _RF_RS(0), /* GOT10 */ _RF_G| _RF_SZ(32) | _RF_RS(0), /* GOT13 */ _RF_G| _RF_SZ(32) | _RF_RS(10), /* GOT22 */ _RF_S|_RF_A|_RF_P| _RF_SZ(32) | _RF_RS(0), /* PC10 */ _RF_S|_RF_A|_RF_P| _RF_SZ(32) | _RF_RS(10), /* PC22 */ _RF_A|_RF_P| _RF_SZ(32) | _RF_RS(2), /* WPLT30 */ _RF_SZ(32) | _RF_RS(0), /* COPY */ _RF_S|_RF_A| _RF_SZ(64) | _RF_RS(0), /* GLOB_DAT */ _RF_SZ(32) | _RF_RS(0), /* JMP_SLOT */ _RF_A| _RF_B| _RF_SZ(64) | _RF_RS(0), /* RELATIVE */ _RF_S|_RF_A| _RF_U| _RF_SZ(32) | _RF_RS(0), /* UA_32 */ _RF_A| _RF_SZ(32) | _RF_RS(0), /* PLT32 */ _RF_A| _RF_SZ(32) | _RF_RS(10), /* HIPLT22 */ _RF_A| _RF_SZ(32) | _RF_RS(0), /* LOPLT10 */ _RF_A|_RF_P| _RF_SZ(32) | _RF_RS(0), /* PCPLT32 */ _RF_A|_RF_P| _RF_SZ(32) | _RF_RS(10), /* PCPLT22 */ _RF_A|_RF_P| _RF_SZ(32) | _RF_RS(0), /* PCPLT10 */ _RF_S|_RF_A| _RF_SZ(32) | _RF_RS(0), /* 10 */ _RF_S|_RF_A| _RF_SZ(32) | _RF_RS(0), /* 11 */ _RF_S|_RF_A| _RF_SZ(64) | _RF_RS(0), /* 64 */ _RF_S|_RF_A|/*extra*/ _RF_SZ(32) | _RF_RS(0), /* OLO10 */ _RF_S|_RF_A| _RF_SZ(32) | _RF_RS(42), /* HH22 */ _RF_S|_RF_A| _RF_SZ(32) | _RF_RS(32), /* HM10 */ _RF_S|_RF_A| _RF_SZ(32) | _RF_RS(10), /* LM22 */ _RF_S|_RF_A|_RF_P| _RF_SZ(32) | _RF_RS(42), /* PC_HH22 */ _RF_S|_RF_A|_RF_P| _RF_SZ(32) | _RF_RS(32), /* PC_HM10 */ _RF_S|_RF_A|_RF_P| _RF_SZ(32) | _RF_RS(10), /* PC_LM22 */ _RF_S|_RF_A|_RF_P| _RF_SZ(32) | _RF_RS(2), /* WDISP16 */ _RF_S|_RF_A|_RF_P| _RF_SZ(32) | _RF_RS(2), /* WDISP19 */ _RF_S|_RF_A| _RF_SZ(32) | _RF_RS(0), /* GLOB_JMP */ _RF_S|_RF_A| _RF_SZ(32) | _RF_RS(0), /* 7 */ _RF_S|_RF_A| _RF_SZ(32) | _RF_RS(0), /* 5 */ _RF_S|_RF_A| _RF_SZ(32) | _RF_RS(0), /* 6 */ _RF_S|_RF_A|_RF_P| _RF_SZ(64) | _RF_RS(0), /* DISP64 */ _RF_A| _RF_SZ(64) | _RF_RS(0), /* PLT64 */ _RF_S|_RF_A| _RF_SZ(32) | _RF_RS(10), /* HIX22 */ _RF_S|_RF_A| _RF_SZ(32) | _RF_RS(0), /* LOX10 */ _RF_S|_RF_A| _RF_SZ(32) | _RF_RS(22), /* H44 */ _RF_S|_RF_A| _RF_SZ(32) | _RF_RS(12), /* M44 */ _RF_S|_RF_A| _RF_SZ(32) | _RF_RS(0), /* L44 */ _RF_S|_RF_A| _RF_SZ(64) | _RF_RS(0), /* REGISTER */ _RF_S|_RF_A| _RF_U| _RF_SZ(64) | _RF_RS(0), /* UA64 */ _RF_S|_RF_A| _RF_U| _RF_SZ(16) | _RF_RS(0), /* UA16 */ /* TLS relocs not represented here! */ }; #ifdef RTLD_DEBUG_RELOC static const char *reloc_names[] = { "NONE", "RELOC_8", "RELOC_16", "RELOC_32", "DISP_8", "DISP_16", "DISP_32", "WDISP_30", "WDISP_22", "HI22", "22", "13", "LO10", "GOT10", "GOT13", "GOT22", "PC10", "PC22", "WPLT30", "COPY", "GLOB_DAT", "JMP_SLOT", "RELATIVE", "UA_32", "PLT32", "HIPLT22", "LOPLT10", "LOPLT10", "PCPLT22", "PCPLT32", "10", "11", "64", "OLO10", "HH22", "HM10", "LM22", "PC_HH22", "PC_HM10", "PC_LM22", "WDISP16", "WDISP19", "GLOB_JMP", "7", "5", "6", "DISP64", "PLT64", "HIX22", "LOX10", "H44", "M44", "L44", "REGISTER", "UA64", "UA16", "TLS_GD_HI22", "TLS_GD_LO10", "TLS_GD_ADD", "TLS_GD_CALL", "TLS_LDM_HI22", "TLS_LDM_LO10", "TLS_LDM_ADD", "TLS_LDM_CALL", "TLS_LDO_HIX22", "TLS_LDO_LOX10", "TLS_LDO_ADD", "TLS_IE_HI22", "TLS_IE_LO10", "TLS_IE_LD", "TLS_IE_LDX", "TLS_IE_ADD", "TLS_LE_HIX22", "TLS_LE_LOX10", "TLS_DTPMOD32", "TLS_DTPMOD64", "TLS_DTPOFF32", "TLS_DTPOFF64", "TLS_TPOFF32", "TLS_TPOFF64", }; #endif #define RELOC_RESOLVE_SYMBOL(t) ((reloc_target_flags[t] & _RF_S) != 0) #define RELOC_PC_RELATIVE(t) ((reloc_target_flags[t] & _RF_P) != 0) #define RELOC_BASE_RELATIVE(t) ((reloc_target_flags[t] & _RF_B) != 0) #define RELOC_UNALIGNED(t) ((reloc_target_flags[t] & _RF_U) != 0) #define RELOC_USE_ADDEND(t) ((reloc_target_flags[t] & _RF_A) != 0) #define RELOC_TARGET_SIZE(t) ((reloc_target_flags[t] >> 8) & 0xff) #define RELOC_VALUE_RIGHTSHIFT(t) (reloc_target_flags[t] & 0xff) #define RELOC_TLS(t) (t >= R_TYPE(TLS_GD_HI22)) static const long reloc_target_bitmask[] = { #define _BM(x) (~(-(1ULL << (x)))) 0, /* NONE */ _BM(8), _BM(16), _BM(32), /* RELOC_8, _16, _32 */ _BM(8), _BM(16), _BM(32), /* DISP8, DISP16, DISP32 */ _BM(30), _BM(22), /* WDISP30, WDISP22 */ _BM(22), _BM(22), /* HI22, _22 */ _BM(13), _BM(10), /* RELOC_13, _LO10 */ _BM(10), _BM(13), _BM(22), /* GOT10, GOT13, GOT22 */ _BM(10), _BM(22), /* _PC10, _PC22 */ _BM(30), 0, /* _WPLT30, _COPY */ -1, _BM(32), -1, /* _GLOB_DAT, JMP_SLOT, _RELATIVE */ _BM(32), _BM(32), /* _UA32, PLT32 */ _BM(22), _BM(10), /* _HIPLT22, LOPLT10 */ _BM(32), _BM(22), _BM(10), /* _PCPLT32, _PCPLT22, _PCPLT10 */ _BM(10), _BM(11), -1, /* _10, _11, _64 */ _BM(13), _BM(22), /* _OLO10, _HH22 */ _BM(10), _BM(22), /* _HM10, _LM22 */ _BM(22), _BM(10), _BM(22), /* _PC_HH22, _PC_HM10, _PC_LM22 */ _BM(16), _BM(19), /* _WDISP16, _WDISP19 */ -1, /* GLOB_JMP */ _BM(7), _BM(5), _BM(6), /* _7, _5, _6 */ -1, -1, /* DISP64, PLT64 */ _BM(22), _BM(13), /* HIX22, LOX10 */ _BM(22), _BM(10), _BM(12), /* H44, M44, L44 */ -1, -1, _BM(16), /* REGISTER, UA64, UA16 */ #undef _BM }; #define RELOC_VALUE_BITMASK(t) (reloc_target_bitmask[t]) /* * Instruction templates: */ /* %hi(v)/%lo(v) with variable shift */ #define HIVAL(v, s) (((v) >> (s)) & 0x003fffff) #define LOVAL(v, s) (((v) >> (s)) & 0x000003ff) void _rtld_bind_start_0(long, long); void _rtld_bind_start_1(long, long); void _rtld_relocate_nonplt_self(Elf_Dyn *, Elf_Addr); caddr_t _rtld_bind(const Obj_Entry *, Elf_Word); /* * Install rtld function call into this PLT slot. */ #define SAVE 0x9de3bf50 /* i.e. `save %sp,-176,%sp' */ #define SETHI_l0 0x21000000 #define SETHI_l1 0x23000000 #define OR_l0_l0 0xa0142000 #define SLLX_l0_32_l0 0xa12c3020 #define OR_l0_l1_l0 0xa0140011 #define JMPL_l0_o0 0x91c42000 #define MOV_g1_o1 0x92100001 void _rtld_install_plt(Elf_Word *, Elf_Addr); static inline int _rtld_relocate_plt_object(const Obj_Entry *, const Elf_Rela *, Elf_Addr *); void _rtld_install_plt(Elf_Word *pltgot, Elf_Addr proc) { pltgot[0] = SAVE; pltgot[1] = SETHI_l0 | HIVAL(proc, 42); pltgot[2] = SETHI_l1 | HIVAL(proc, 10); pltgot[3] = OR_l0_l0 | LOVAL(proc, 32); pltgot[4] = SLLX_l0_32_l0; pltgot[5] = OR_l0_l1_l0; pltgot[6] = JMPL_l0_o0 | LOVAL(proc, 0); pltgot[7] = MOV_g1_o1; } void _rtld_setup_pltgot(const Obj_Entry *obj) { /* * On sparc64 we got troubles. * * Instructions are 4 bytes long. * Elf[64]_Addr is 8 bytes long, so are our pltglot[] * array entries. * Each PLT entry jumps to PLT0 to enter the dynamic * linker. * Loading an arbitrary 64-bit pointer takes 6 * instructions and 2 registers. * * Somehow we need to issue a save to get a new stack * frame, load the address of the dynamic linker, and * jump there, in 8 instructions or less. * * Oh, we need to fill out both PLT0 and PLT1. */ { Elf_Word *entry = (Elf_Word *)obj->pltgot; /* Install in entries 0 and 1 */ _rtld_install_plt(&entry[0], (Elf_Addr) &_rtld_bind_start_0); _rtld_install_plt(&entry[8], (Elf_Addr) &_rtld_bind_start_1); /* * Install the object reference in first slot * of entry 2. */ obj->pltgot[8] = (Elf_Addr) obj; } } void _rtld_relocate_nonplt_self(Elf_Dyn *dynp, Elf_Addr relocbase) { const Elf_Rela *rela = 0, *relalim; Elf_Addr relasz = 0; Elf_Addr *where; for (; dynp->d_tag != DT_NULL; dynp++) { switch (dynp->d_tag) { case DT_RELA: rela = (const Elf_Rela *)(relocbase + dynp->d_un.d_ptr); break; case DT_RELASZ: relasz = dynp->d_un.d_val; break; } } relalim = (const Elf_Rela *)((const uint8_t *)rela + relasz); for (; rela < relalim; rela++) { where = (Elf_Addr *)(relocbase + rela->r_offset); *where = (Elf_Addr)(relocbase + rela->r_addend); } } int _rtld_relocate_nonplt_objects(Obj_Entry *obj) { const Elf_Rela *rela; const Elf_Sym *def = NULL; const Obj_Entry *defobj = NULL; unsigned long last_symnum = ULONG_MAX; for (rela = obj->rela; rela < obj->relalim; rela++) { Elf_Addr *where; Elf_Word type; Elf_Addr value = 0, mask; unsigned long symnum; where = (Elf_Addr *) (obj->relocbase + rela->r_offset); type = ELF_R_TYPE(rela->r_info); if (type == R_TYPE(NONE)) continue; /* OLO10 relocations have extra info */ if ((type & 0x00ff) == R_SPARC_OLO10) type = R_SPARC_OLO10; /* We do JMP_SLOTs in _rtld_bind() below */ if (type == R_TYPE(JMP_SLOT)) continue; /* IFUNC relocations are handled in _rtld_call_ifunc */ if (type == R_TYPE(IRELATIVE)) { if (obj->ifunc_remaining_nonplt == 0) { obj->ifunc_remaining_nonplt = obj->relalim - rela; } continue; } /* COPY relocs are also handled elsewhere */ if (type == R_TYPE(COPY)) continue; /* * We use the fact that relocation types are an `enum' * Note: R_SPARC_TLS_TPOFF64 is currently numerically largest. */ if (type > R_TYPE(TLS_TPOFF64)) { dbg(("unknown relocation type %x at %p", type, rela)); return -1; } value = rela->r_addend; if (RELOC_RESOLVE_SYMBOL(type) || RELOC_TLS(type)) { symnum = ELF_R_SYM(rela->r_info); if (last_symnum != symnum) { last_symnum = symnum; def = _rtld_find_symdef(symnum, obj, &defobj, false); if (def == NULL) return -1; } } /* * Handle TLS relocations here, they are different. */ if (RELOC_TLS(type)) { switch (type) { case R_TYPE(TLS_DTPMOD64): *where = (Elf64_Addr)defobj->tlsindex; rdbg(("TLS_DTPMOD64 %s in %s --> %p", obj->strtab + obj->symtab[symnum].st_name, obj->path, (void *)*where)); break; case R_TYPE(TLS_DTPOFF64): *where = (Elf64_Addr)(def->st_value + rela->r_addend); rdbg(("DTPOFF64 %s in %s --> %p", obj->strtab + obj->symtab[symnum].st_name, obj->path, (void *)*where)); break; case R_TYPE(TLS_TPOFF64): if (!defobj->tls_static && _rtld_tls_offset_allocate(__UNCONST(defobj))) return -1; *where = (Elf64_Addr)(def->st_value - defobj->tlsoffset + rela->r_addend); rdbg(("TLS_TPOFF64 %s in %s --> %p", obj->strtab + obj->symtab[symnum].st_name, obj->path, (void *)*where)); break; } continue; } /* * Handle relative relocs here, as an optimization. */ if (type == R_TYPE(RELATIVE)) { *where = (Elf_Addr)(obj->relocbase + value); rdbg(("RELATIVE in %s --> %p", obj->path, (void *)*where)); continue; } if (RELOC_RESOLVE_SYMBOL(type)) { /* Add in the symbol's absolute address */ value += (Elf_Addr)(defobj->relocbase + def->st_value); } if (type == R_SPARC_OLO10) { value = (value & 0x3ff) + (((Elf64_Xword)rela->r_info<<32)>>40); } if (RELOC_PC_RELATIVE(type)) { value -= (Elf_Addr)where; } if (RELOC_BASE_RELATIVE(type)) { /* * Note that even though sparcs use `Elf_rela' * exclusively we still need the implicit memory addend * in relocations referring to GOT entries. * Undoubtedly, someone f*cked this up in the distant * past, and now we're stuck with it in the name of * compatibility for all eternity.. * * In any case, the implicit and explicit should be * mutually exclusive. We provide a check for that * here. */ #ifdef DIAGNOSTIC if (value != 0 && *where != 0) { xprintf("BASE_REL(%s): where=%p, *where 0x%lx, " "addend=0x%lx, base %p\n", obj->path, where, *where, rela->r_addend, obj->relocbase); } #endif /* XXXX -- apparently we ignore the preexisting value */ value += (Elf_Addr)(obj->relocbase); } mask = RELOC_VALUE_BITMASK(type); value >>= RELOC_VALUE_RIGHTSHIFT(type); value &= mask; if (RELOC_UNALIGNED(type)) { /* Handle unaligned relocations. */ Elf_Addr tmp = 0; char *ptr = (char *)where; int i, size = RELOC_TARGET_SIZE(type)/8; /* Read it in one byte at a time. */ for (i=0; i> (8*i)) & 0xff); #ifdef RTLD_DEBUG_RELOC value = (Elf_Addr)tmp; #endif } else if (RELOC_TARGET_SIZE(type) > 32) { *where &= ~mask; *where |= value; #ifdef RTLD_DEBUG_RELOC value = (Elf_Addr)*where; #endif } else { Elf32_Addr *where32 = (Elf32_Addr *)where; *where32 &= ~mask; *where32 |= value; #ifdef RTLD_DEBUG_RELOC value = (Elf_Addr)*where32; #endif } #ifdef RTLD_DEBUG_RELOC if (RELOC_RESOLVE_SYMBOL(type)) { rdbg(("%s %s in %s --> %p in %s", reloc_names[type], obj->strtab + obj->symtab[symnum].st_name, obj->path, (void *)value, defobj->path)); } else { rdbg(("%s in %s --> %p", reloc_names[type], obj->path, (void *)value)); } #endif } return (0); } int _rtld_relocate_plt_lazy(Obj_Entry *obj) { const Elf_Rela *rela; for (rela = obj->pltrelalim; rela-- > obj->pltrela; ) { if (ELF_R_TYPE(rela->r_info) == R_TYPE(JMP_IREL)) obj->ifunc_remaining = obj->pltrelalim - rela + 1; } return 0; } caddr_t _rtld_bind(const Obj_Entry *obj, Elf_Word reloff) { const Elf_Rela *rela = obj->pltrela + reloff; Elf_Addr result; int err; result = 0; /* XXX gcc */ if (ELF_R_TYPE(obj->pltrela->r_info) == R_TYPE(JMP_SLOT) || ELF_R_TYPE(obj->pltrela->r_info) == R_TYPE(JMP_IREL)) { /* * XXXX * * The first four PLT entries are reserved. There is some * disagreement whether they should have associated relocation * entries. Both the SPARC 32-bit and 64-bit ELF * specifications say that they should have relocation entries, * but the 32-bit SPARC binutils do not generate them, and now * the 64-bit SPARC binutils have stopped generating them too. * * So, to provide binary compatibility, we will check the first * entry, if it is reserved it should not be of the type * JMP_SLOT or JMP_REL. If it is either of those, then * the 4 reserved entries were not generated and our index * is 4 entries too far. */ rela -= 4; } _rtld_shared_enter(); err = _rtld_relocate_plt_object(obj, rela, &result); if (err) _rtld_die(); _rtld_shared_exit(); return (caddr_t)result; } int _rtld_relocate_plt_objects(const Obj_Entry *obj) { const Elf_Rela *rela; rela = obj->pltrela; /* * Check for first four reserved entries - and skip them. * See above for details. */ if (ELF_R_TYPE(obj->pltrela->r_info) != R_TYPE(JMP_SLOT) && ELF_R_TYPE(obj->pltrela->r_info) != R_TYPE(JMP_IREL)) rela += 4; for (; rela < obj->pltrelalim; rela++) if (_rtld_relocate_plt_object(obj, rela, NULL) < 0) return -1; return 0; } static inline void _rtld_write_plt(Elf_Word *where, Elf_Addr value, const Elf_Rela *rela, const Obj_Entry *obj) { if (rela && rela->r_addend) { Elf_Addr *ptr = (Elf_Addr *)where; /* * This entry is >= 32768. The relocations points to a * PC-relative pointer to the bind_0 stub at the top of the * PLT section. Update it to point to the target function. */ ptr[0] += value - (Elf_Addr)obj->pltgot; } else { sparc_write_branch(where + 1, (void *)value); } } /* * New inline function that is called by _rtld_relocate_plt_object and * _rtld_bind */ static inline int _rtld_relocate_plt_object(const Obj_Entry *obj, const Elf_Rela *rela, Elf_Addr *tp) { Elf_Word *where = (Elf_Word *)(obj->relocbase + rela->r_offset); const Elf_Sym *def; const Obj_Entry *defobj; Elf_Addr value; unsigned long info = rela->r_info; if (ELF_R_TYPE(info) == R_TYPE(JMP_IREL)) return 0; assert(ELF_R_TYPE(info) == R_TYPE(JMP_SLOT)); def = _rtld_find_plt_symdef(ELF_R_SYM(info), obj, &defobj, tp != NULL); if (__predict_false(def == NULL)) return -1; if (__predict_false(def == &_rtld_sym_zero)) return 0; if (ELF_ST_TYPE(def->st_info) == STT_GNU_IFUNC) { if (tp == NULL) return 0; value = _rtld_resolve_ifunc(defobj, def); } else { value = (Elf_Addr)(defobj->relocbase + def->st_value); } rdbg(("bind now/fixup in %s at %p --> new=%p", defobj->strtab + def->st_name, (void*)where, (void *)value)); _rtld_write_plt(where, value, rela, obj); if (tp) *tp = value; return 0; }