diff options
Diffstat (limited to 'ldso/ldso/hash.c')
-rw-r--r-- | ldso/ldso/hash.c | 262 |
1 files changed, 0 insertions, 262 deletions
diff --git a/ldso/ldso/hash.c b/ldso/ldso/hash.c deleted file mode 100644 index c33b329ec..000000000 --- a/ldso/ldso/hash.c +++ /dev/null @@ -1,262 +0,0 @@ -/* vi: set sw=4 ts=4: */ -/* - * Program to load an ELF binary on a linux system, and run it - * after resolving ELF shared library symbols - * - * 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 - * - * 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. The name of the above contributors may not be - * used to endorse or promote products derived from this software - * without specific prior written permission. - * - * THIS SOFTWARE IS PROVIDED BY THE 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 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. - */ - - -/* Various symbol table handling functions, including symbol lookup */ - -/* - * 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, - * as well as all of the other good stuff in the binary. - */ -struct elf_resolve *_dl_loaded_modules = NULL; - -/* - * This is the list of modules that are loaded when the image is first - * started. As we add more via dlopen, they get added into other - * chains. - */ -struct dyn_elf *_dl_symbol_tables = NULL; - -/* - * This is the list of modules that are loaded via dlopen. We may need - * to search these for RTLD_GLOBAL files. - */ -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. */ -unsigned long _dl_elf_hash(const char *name) -{ - unsigned long hash = 0; - unsigned long tmp; - - while (*name) { - hash = (hash << 4) + *name++; - if ((tmp = hash & 0xf0000000)) - hash ^= tmp >> 24; - hash &= ~tmp; - }; - return hash; -} - -/* 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; - int len = _dl_strlen(libname); - - for (tpnt = _dl_loaded_modules; tpnt; tpnt = tpnt->next) { - if (_dl_strncmp(tpnt->libname, libname, len) == 0 && - (tpnt->libname[len] == '\0' || tpnt->libname[len] == '.')) - return tpnt; - } - - return NULL; -} - -/* - * We call this function when we have just read an ELF library or executable. - * 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, - unsigned long dynamic_size) -{ - unsigned long *hash_addr; - struct elf_resolve *tpnt; - int i; - - if (!_dl_loaded_modules) { - 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; - while (tpnt->next) - tpnt = tpnt->next; - tpnt->next = (struct elf_resolve *) _dl_malloc(sizeof(struct elf_resolve)); - _dl_memset(tpnt->next, 0, sizeof(struct elf_resolve)); - tpnt->next->prev = tpnt; - tpnt = tpnt->next; - }; - - tpnt->next = NULL; - tpnt->init_flag = 0; - tpnt->libname = _dl_strdup(libname); - tpnt->dynamic_addr = (ElfW(Dyn) *)dynamic_addr; - tpnt->dynamic_size = dynamic_size; - tpnt->libtype = loaded_file; - - if (dynamic_info[DT_HASH] != 0) { - hash_addr = (unsigned long *) (intptr_t)(dynamic_info[DT_HASH] + loadaddr); - tpnt->nbucket = *hash_addr++; - tpnt->nchain = *hash_addr++; - tpnt->elf_buckets = hash_addr; - hash_addr += tpnt->nbucket; - tpnt->chains = hash_addr; - } - tpnt->loadaddr = (ElfW(Addr))loadaddr; - for (i = 0; i < 24; i++) - tpnt->dynamic_info[i] = dynamic_info[i]; -#ifdef __mips__ - { - Elf32_Dyn *dpnt = (Elf32_Dyn *) dynamic_addr; - - while(dpnt->d_tag) { - if (dpnt->d_tag == DT_MIPS_GOTSYM) - tpnt->mips_gotsym = dpnt->d_un.d_val; - if (dpnt->d_tag == DT_MIPS_LOCAL_GOTNO) - tpnt->mips_local_gotno = dpnt->d_un.d_val; - if (dpnt->d_tag == DT_MIPS_SYMTABNO) - tpnt->mips_symtabno = dpnt->d_un.d_val; - dpnt++; - } - } -#endif - return tpnt; -} - - -/* - * 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, - struct elf_resolve *f_tpnt, enum caller_type caller_type) -{ - struct elf_resolve *tpnt; - int si; - int pass; - char *strtab; - Elf32_Sym *symtab; - unsigned long elf_hash_number, hn; - char *weak_result; - struct dyn_elf *rpnt, first; - const ElfW(Sym) *sym; - - weak_result = 0; - elf_hash_number = _dl_elf_hash(name); - - /* A quick little hack to make sure that any symbol in the executable - will be preferred to one in a shared library. This is necessary so - 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 && rpnt1) { - first = (*_dl_symbol_tables); - first.next = rpnt1; - rpnt1 = (&first); - } - - /* - * The passes are so that we can first search the regular symbols - * for whatever module was specified, and then search anything - * loaded with RTLD_GLOBAL. When pass is 1, it means we are just - * starting the first dlopened module, and anything above that - * is just the next one in the chain. - */ - for (pass = 0; (1 == 1); pass++) { - - /* - * If we are just starting to search for RTLD_GLOBAL, setup - * the pointer for the start of the search. - */ - if (pass == 1) { - rpnt1 = _dl_handles; - } - - /* - * Anything after this, we need to skip to the next module. - */ - else if (pass >= 2) { - rpnt1 = rpnt1->next_handle; - } - - /* - * Make sure we still have a module, and make sure that this - * module was loaded with RTLD_GLOBAL. - */ - if (pass != 0) { - if (rpnt1 == NULL) - break; - //if ((rpnt1->flags & RTLD_GLOBAL) == 0) - //continue; - } - - for (rpnt = (rpnt1 ? rpnt1 : _dl_symbol_tables); rpnt; rpnt = rpnt->next) { - tpnt = rpnt->dyn; - - /* Don't search the executable when resolving a copy reloc. */ - if (tpnt->libtype == elf_executable && caller_type == copyrel) - continue; - - /* - * Avoid calling .urem here. - */ - 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); - - 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; - } - } - } - } - return weak_result; -} |