diff options
| -rw-r--r-- | ldso/ldso/dl-hash.c | 155 | ||||
| -rw-r--r-- | ldso/ldso/hash.c | 155 |
2 files changed, 90 insertions, 220 deletions
diff --git a/ldso/ldso/dl-hash.c b/ldso/ldso/dl-hash.c index 1eb7c5dd9..1e4acd979 100644 --- a/ldso/ldso/dl-hash.c +++ b/ldso/ldso/dl-hash.c @@ -1,12 +1,12 @@ /* vi: set sw=4 ts=4: */ -/* Program to load an ELF binary on a linux system, and run it +/* + * Program to load an ELF binary on a linux system, and run it * after resolving ELF shared library symbols * - * Copyright (c) 1994-2000 Eric Youngdale, Peter MacDonald, + * Copyright (C) 2004 by Joakim Tjernlund <joakim.tjernlund@lumentis.se> + * Copyright (C) 2000-2004 by Erik Andersen <andersen@codpoet.org> + * Copyright (c) 1994-2000 Eric Youngdale, Peter MacDonald, * David Engel, Hongjiu Lu and Mitch D'Souza - * Copyright (C) 2001-2002, Erik Andersen - * - * All rights reserved. * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions @@ -35,10 +35,9 @@ /* * This is the start of the linked list that describes all of the files present - * in the system with pointers to all of the symbol, string, and hash tables, + * in the system with pointers to all of the symbol, string, and hash tables, * as well as all of the other good stuff in the binary. */ - struct elf_resolve *_dl_loaded_modules = NULL; /* @@ -55,12 +54,9 @@ struct dyn_elf *_dl_symbol_tables = NULL; struct dyn_elf *_dl_handles = NULL; -/* - * This is the hash function that is used by the ELF linker to generate - * the hash table that each executable and library is required to - * have. We need it to decode the hash table. - */ - +/* This is the hash function that is used by the ELF linker to generate the + * hash table that each executable and library is required to have. We need + * it to decode the hash table. */ unsigned long _dl_elf_hash(const char *name) { unsigned long hash = 0; @@ -75,9 +71,7 @@ unsigned long _dl_elf_hash(const char *name) return hash; } -/* - * Check to see if a library has already been added to the hash chain. - */ +/* Check to see if a library has already been added to the hash chain. */ struct elf_resolve *_dl_check_hashed_files(const char *libname) { struct elf_resolve *tpnt; @@ -97,9 +91,8 @@ struct elf_resolve *_dl_check_hashed_files(const char *libname) * We add the relevant info to the symbol chain, so that we can resolve all * externals properly. */ - -struct elf_resolve *_dl_add_elf_hash_table(const char *libname, - char *loadaddr, unsigned long *dynamic_info, unsigned long dynamic_addr, +struct elf_resolve *_dl_add_elf_hash_table(const char *libname, + char *loadaddr, unsigned long *dynamic_info, unsigned long dynamic_addr, unsigned long dynamic_size) { unsigned long *hash_addr; @@ -107,8 +100,7 @@ struct elf_resolve *_dl_add_elf_hash_table(const char *libname, int i; if (!_dl_loaded_modules) { - tpnt = _dl_loaded_modules = - (struct elf_resolve *) _dl_malloc(sizeof(struct elf_resolve)); + tpnt = _dl_loaded_modules = (struct elf_resolve *) _dl_malloc(sizeof(struct elf_resolve)); _dl_memset(tpnt, 0, sizeof(struct elf_resolve)); } else { tpnt = _dl_loaded_modules; @@ -161,21 +153,18 @@ struct elf_resolve *_dl_add_elf_hash_table(const char *libname, * This function resolves externals, and this is either called when we process * relocations or when we call an entry in the PLT table for the first time. */ - -char *_dl_find_hash(const char *name, struct dyn_elf *rpnt1, +char *_dl_find_hash(const char *name, struct dyn_elf *rpnt1, struct elf_resolve *f_tpnt, enum caller_type caller_type) { struct elf_resolve *tpnt; int si; - char *pnt; int pass; char *strtab; Elf32_Sym *symtab; unsigned long elf_hash_number, hn; char *weak_result; - struct elf_resolve *first_def; struct dyn_elf *rpnt, first; - char *data_result = 0; /* nakao */ + const ElfW(Sym) *sym; weak_result = 0; elf_hash_number = _dl_elf_hash(name); @@ -185,7 +174,7 @@ char *_dl_find_hash(const char *name, struct dyn_elf *rpnt1, that any shared library data symbols referenced in the executable will be seen at the same address by the executable, shared libraries and dynamically loaded code. -Rob Ryan (robr@cmu.edu) */ - if (_dl_symbol_tables && !caller_type && rpnt1) { + if (_dl_symbol_tables && rpnt1) { first = (*_dl_symbol_tables); first.next = rpnt1; rpnt1 = (&first); @@ -222,24 +211,16 @@ char *_dl_find_hash(const char *name, struct dyn_elf *rpnt1, if (pass != 0) { if (rpnt1 == NULL) break; - if ((rpnt1->flags & RTLD_GLOBAL) == 0) - continue; + //if ((rpnt1->flags & RTLD_GLOBAL) == 0) + //continue; } for (rpnt = (rpnt1 ? rpnt1 : _dl_symbol_tables); rpnt; rpnt = rpnt->next) { tpnt = rpnt->dyn; - /* - * The idea here is that if we are using dlsym, we want to - * first search the entire chain loaded from dlopen, and - * return a result from that if we found anything. If this - * fails, then we continue the search into the stuff loaded - * when the image was activated. For normal lookups, we start - * with rpnt == NULL, so we should never hit this. - */ - if (tpnt->libtype == elf_executable && weak_result != 0) { - break; - } + /* Don't search the executable when resolving a copy reloc. */ + if (tpnt->libtype == elf_executable && caller_type == copyrel) + continue; /* * Avoid calling .urem here. @@ -247,81 +228,35 @@ char *_dl_find_hash(const char *name, struct dyn_elf *rpnt1, do_rem(hn, elf_hash_number, tpnt->nbucket); symtab = (Elf32_Sym *) (intptr_t) (tpnt->dynamic_info[DT_SYMTAB] + tpnt->loadaddr); strtab = (char *) (tpnt->dynamic_info[DT_STRTAB] + tpnt->loadaddr); - /* - * This crap is required because the first instance of a - * symbol on the chain will be used for all symbol references. - * Thus this instance must be resolved to an address that - * contains the actual function, - */ - - first_def = NULL; - - for (si = tpnt->elf_buckets[hn]; si; si = tpnt->chains[si]) { - pnt = strtab + symtab[si].st_name; - - if (_dl_strcmp(pnt, name) == 0 && - symtab[si].st_value != 0) - { - if ((ELF32_ST_TYPE(symtab[si].st_info) == STT_FUNC || - ELF32_ST_TYPE(symtab[si].st_info) == STT_NOTYPE || - ELF32_ST_TYPE(symtab[si].st_info) == STT_OBJECT) && - symtab[si].st_shndx != SHN_UNDEF) { - - /* Here we make sure that we find a module where the symbol is - * actually defined. - */ - - if (f_tpnt) { - if (!first_def) - first_def = tpnt; - if (first_def == f_tpnt - && symtab[si].st_shndx == 0) - continue; - } - switch (ELF32_ST_BIND(symtab[si].st_info)) { - case STB_GLOBAL: - if (tpnt->libtype != elf_executable && - ELF32_ST_TYPE(symtab[si].st_info) - == STT_NOTYPE) - { /* nakao */ - data_result = (char *)tpnt->loadaddr + - symtab[si].st_value; /* nakao */ - break; /* nakao */ - } else /* nakao */ - return (char*)tpnt->loadaddr + symtab[si].st_value; - case STB_WEAK: - if (!weak_result) - weak_result = (char *)tpnt->loadaddr + symtab[si].st_value; - break; - default: /* Do local symbols need to be examined? */ - break; - } - } -#ifndef __mips__ - /* - * References to the address of a function from an executable file and - * the shared objects associated with it might not resolve to the same - * value. To allow comparisons of function addresses we must resolve - * to the address of the plt entry of the executable instead of the - * real function address. - * see "TIS ELF Specification Version 1.2, Book 3, A-11 (Function - * Adresses) - */ - if (resolver != caller_type && - NULL==f_tpnt && /*trick: don't handle R_??_JMP_SLOT reloc type*/ - tpnt->libtype == elf_executable && - ELF32_ST_TYPE(symtab[si].st_info) == STT_FUNC && - symtab[si].st_shndx == SHN_UNDEF) - { - return (char*)symtab[si].st_value; - } + for (si = tpnt->elf_buckets[hn]; si != STN_UNDEF; si = tpnt->chains[si]) { + sym = &symtab[si]; + + if (sym->st_value == 0) + continue; + if (ELF32_ST_TYPE(sym->st_info) > STT_FUNC) + continue; + if (sym->st_shndx == SHN_UNDEF && caller_type != copyrel) + continue; + if (_dl_strcmp(strtab + sym->st_name, name) != 0) + continue; + + switch (ELF32_ST_BIND(sym->st_info)) { + case STB_WEAK: +//Disable this to match current glibc behavior. Of course, +//this doesn't actually work yet and will cause segfaults... +#if 1 + if (!weak_result) + weak_result = (char *)tpnt->loadaddr + sym->st_value; + break; #endif + case STB_GLOBAL: + return (char*)tpnt->loadaddr + sym->st_value; + default: /* Local symbols not handled here */ + break; } } } } - if (data_result) - return data_result; /* nakao */ return weak_result; } diff --git a/ldso/ldso/hash.c b/ldso/ldso/hash.c index 1eb7c5dd9..1e4acd979 100644 --- a/ldso/ldso/hash.c +++ b/ldso/ldso/hash.c @@ -1,12 +1,12 @@ /* vi: set sw=4 ts=4: */ -/* Program to load an ELF binary on a linux system, and run it +/* + * Program to load an ELF binary on a linux system, and run it * after resolving ELF shared library symbols * - * Copyright (c) 1994-2000 Eric Youngdale, Peter MacDonald, + * Copyright (C) 2004 by Joakim Tjernlund <joakim.tjernlund@lumentis.se> + * Copyright (C) 2000-2004 by Erik Andersen <andersen@codpoet.org> + * Copyright (c) 1994-2000 Eric Youngdale, Peter MacDonald, * David Engel, Hongjiu Lu and Mitch D'Souza - * Copyright (C) 2001-2002, Erik Andersen - * - * All rights reserved. * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions @@ -35,10 +35,9 @@ /* * This is the start of the linked list that describes all of the files present - * in the system with pointers to all of the symbol, string, and hash tables, + * in the system with pointers to all of the symbol, string, and hash tables, * as well as all of the other good stuff in the binary. */ - struct elf_resolve *_dl_loaded_modules = NULL; /* @@ -55,12 +54,9 @@ struct dyn_elf *_dl_symbol_tables = NULL; struct dyn_elf *_dl_handles = NULL; -/* - * This is the hash function that is used by the ELF linker to generate - * the hash table that each executable and library is required to - * have. We need it to decode the hash table. - */ - +/* This is the hash function that is used by the ELF linker to generate the + * hash table that each executable and library is required to have. We need + * it to decode the hash table. */ unsigned long _dl_elf_hash(const char *name) { unsigned long hash = 0; @@ -75,9 +71,7 @@ unsigned long _dl_elf_hash(const char *name) return hash; } -/* - * Check to see if a library has already been added to the hash chain. - */ +/* Check to see if a library has already been added to the hash chain. */ struct elf_resolve *_dl_check_hashed_files(const char *libname) { struct elf_resolve *tpnt; @@ -97,9 +91,8 @@ struct elf_resolve *_dl_check_hashed_files(const char *libname) * We add the relevant info to the symbol chain, so that we can resolve all * externals properly. */ - -struct elf_resolve *_dl_add_elf_hash_table(const char *libname, - char *loadaddr, unsigned long *dynamic_info, unsigned long dynamic_addr, +struct elf_resolve *_dl_add_elf_hash_table(const char *libname, + char *loadaddr, unsigned long *dynamic_info, unsigned long dynamic_addr, unsigned long dynamic_size) { unsigned long *hash_addr; @@ -107,8 +100,7 @@ struct elf_resolve *_dl_add_elf_hash_table(const char *libname, int i; if (!_dl_loaded_modules) { - tpnt = _dl_loaded_modules = - (struct elf_resolve *) _dl_malloc(sizeof(struct elf_resolve)); + tpnt = _dl_loaded_modules = (struct elf_resolve *) _dl_malloc(sizeof(struct elf_resolve)); _dl_memset(tpnt, 0, sizeof(struct elf_resolve)); } else { tpnt = _dl_loaded_modules; @@ -161,21 +153,18 @@ struct elf_resolve *_dl_add_elf_hash_table(const char *libname, * This function resolves externals, and this is either called when we process * relocations or when we call an entry in the PLT table for the first time. */ - -char *_dl_find_hash(const char *name, struct dyn_elf *rpnt1, +char *_dl_find_hash(const char *name, struct dyn_elf *rpnt1, struct elf_resolve *f_tpnt, enum caller_type caller_type) { struct elf_resolve *tpnt; int si; - char *pnt; int pass; char *strtab; Elf32_Sym *symtab; unsigned long elf_hash_number, hn; char *weak_result; - struct elf_resolve *first_def; struct dyn_elf *rpnt, first; - char *data_result = 0; /* nakao */ + const ElfW(Sym) *sym; weak_result = 0; elf_hash_number = _dl_elf_hash(name); @@ -185,7 +174,7 @@ char *_dl_find_hash(const char *name, struct dyn_elf *rpnt1, that any shared library data symbols referenced in the executable will be seen at the same address by the executable, shared libraries and dynamically loaded code. -Rob Ryan (robr@cmu.edu) */ - if (_dl_symbol_tables && !caller_type && rpnt1) { + if (_dl_symbol_tables && rpnt1) { first = (*_dl_symbol_tables); first.next = rpnt1; rpnt1 = (&first); @@ -222,24 +211,16 @@ char *_dl_find_hash(const char *name, struct dyn_elf *rpnt1, if (pass != 0) { if (rpnt1 == NULL) break; - if ((rpnt1->flags & RTLD_GLOBAL) == 0) - continue; + //if ((rpnt1->flags & RTLD_GLOBAL) == 0) + //continue; } for (rpnt = (rpnt1 ? rpnt1 : _dl_symbol_tables); rpnt; rpnt = rpnt->next) { tpnt = rpnt->dyn; - /* - * The idea here is that if we are using dlsym, we want to - * first search the entire chain loaded from dlopen, and - * return a result from that if we found anything. If this - * fails, then we continue the search into the stuff loaded - * when the image was activated. For normal lookups, we start - * with rpnt == NULL, so we should never hit this. - */ - if (tpnt->libtype == elf_executable && weak_result != 0) { - break; - } + /* Don't search the executable when resolving a copy reloc. */ + if (tpnt->libtype == elf_executable && caller_type == copyrel) + continue; /* * Avoid calling .urem here. @@ -247,81 +228,35 @@ char *_dl_find_hash(const char *name, struct dyn_elf *rpnt1, do_rem(hn, elf_hash_number, tpnt->nbucket); symtab = (Elf32_Sym *) (intptr_t) (tpnt->dynamic_info[DT_SYMTAB] + tpnt->loadaddr); strtab = (char *) (tpnt->dynamic_info[DT_STRTAB] + tpnt->loadaddr); - /* - * This crap is required because the first instance of a - * symbol on the chain will be used for all symbol references. - * Thus this instance must be resolved to an address that - * contains the actual function, - */ - - first_def = NULL; - - for (si = tpnt->elf_buckets[hn]; si; si = tpnt->chains[si]) { - pnt = strtab + symtab[si].st_name; - - if (_dl_strcmp(pnt, name) == 0 && - symtab[si].st_value != 0) - { - if ((ELF32_ST_TYPE(symtab[si].st_info) == STT_FUNC || - ELF32_ST_TYPE(symtab[si].st_info) == STT_NOTYPE || - ELF32_ST_TYPE(symtab[si].st_info) == STT_OBJECT) && - symtab[si].st_shndx != SHN_UNDEF) { - - /* Here we make sure that we find a module where the symbol is - * actually defined. - */ - - if (f_tpnt) { - if (!first_def) - first_def = tpnt; - if (first_def == f_tpnt - && symtab[si].st_shndx == 0) - continue; - } - switch (ELF32_ST_BIND(symtab[si].st_info)) { - case STB_GLOBAL: - if (tpnt->libtype != elf_executable && - ELF32_ST_TYPE(symtab[si].st_info) - == STT_NOTYPE) - { /* nakao */ - data_result = (char *)tpnt->loadaddr + - symtab[si].st_value; /* nakao */ - break; /* nakao */ - } else /* nakao */ - return (char*)tpnt->loadaddr + symtab[si].st_value; - case STB_WEAK: - if (!weak_result) - weak_result = (char *)tpnt->loadaddr + symtab[si].st_value; - break; - default: /* Do local symbols need to be examined? */ - break; - } - } -#ifndef __mips__ - /* - * References to the address of a function from an executable file and - * the shared objects associated with it might not resolve to the same - * value. To allow comparisons of function addresses we must resolve - * to the address of the plt entry of the executable instead of the - * real function address. - * see "TIS ELF Specification Version 1.2, Book 3, A-11 (Function - * Adresses) - */ - if (resolver != caller_type && - NULL==f_tpnt && /*trick: don't handle R_??_JMP_SLOT reloc type*/ - tpnt->libtype == elf_executable && - ELF32_ST_TYPE(symtab[si].st_info) == STT_FUNC && - symtab[si].st_shndx == SHN_UNDEF) - { - return (char*)symtab[si].st_value; - } + for (si = tpnt->elf_buckets[hn]; si != STN_UNDEF; si = tpnt->chains[si]) { + sym = &symtab[si]; + + if (sym->st_value == 0) + continue; + if (ELF32_ST_TYPE(sym->st_info) > STT_FUNC) + continue; + if (sym->st_shndx == SHN_UNDEF && caller_type != copyrel) + continue; + if (_dl_strcmp(strtab + sym->st_name, name) != 0) + continue; + + switch (ELF32_ST_BIND(sym->st_info)) { + case STB_WEAK: +//Disable this to match current glibc behavior. Of course, +//this doesn't actually work yet and will cause segfaults... +#if 1 + if (!weak_result) + weak_result = (char *)tpnt->loadaddr + sym->st_value; + break; #endif + case STB_GLOBAL: + return (char*)tpnt->loadaddr + sym->st_value; + default: /* Local symbols not handled here */ + break; } } } } - if (data_result) - return data_result; /* nakao */ return weak_result; } |