diff options
Diffstat (limited to 'elf')
| -rw-r--r-- | elf/Makefile | 2 | ||||
| -rw-r--r-- | elf/dl-addr.c | 85 | ||||
| -rw-r--r-- | elf/dl-runtime.c | 174 | ||||
| -rw-r--r-- | elf/dladdr.c | 64 | ||||
| -rw-r--r-- | elf/dlfcn.h | 2 | ||||
| -rw-r--r-- | elf/link.h | 4 | ||||
| -rw-r--r-- | elf/rtld.c | 2 |
7 files changed, 181 insertions, 152 deletions
diff --git a/elf/Makefile b/elf/Makefile index fb85b85..5f78c5c 100644 --- a/elf/Makefile +++ b/elf/Makefile @@ -22,7 +22,7 @@ subdir := elf headers = elf.h bits/elfclass.h bits/dlfcn.h link.h dlfcn.h routines = $(dl-routines) dl-open dl-close dl-symbol dl-support \ - enbl-secure + dl-addr enbl-secure # The core dynamic linking functions are in libc for the static and # profiled libraries. diff --git a/elf/dl-addr.c b/elf/dl-addr.c new file mode 100644 index 0000000..d50cc4b --- /dev/null +++ b/elf/dl-addr.c @@ -0,0 +1,85 @@ +/* Locate the shared object symbol nearest a given address. + Copyright (C) 1996, 1997 Free Software Foundation, Inc. + This file is part of the GNU C Library. + + The GNU C Library is free software; you can redistribute it and/or + modify it under the terms of the GNU Library General Public License as + published by the Free Software Foundation; either version 2 of the + License, or (at your option) any later version. + + The GNU C Library is distributed in the hope that it will be useful, + but WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + Library General Public License for more details. + + You should have received a copy of the GNU Library General Public + License along with the GNU C Library; see the file COPYING.LIB. If not, + write to the Free Software Foundation, Inc., 59 Temple Place - Suite 330, + Boston, MA 02111-1307, USA. */ + +#include <stddef.h> +#include <link.h> +#include <dlfcn.h> + + +int +_dl_addr (const void *address, Dl_info *info) +{ + const ElfW(Addr) addr = (ElfW(Addr)) address; + struct link_map *l, *match; + const ElfW(Sym) *symtab, *matchsym; + const char *strtab; + + /* Find the highest-addressed object that ADDRESS is not below. */ + match = NULL; + for (l = _dl_loaded; l; l = l->l_next) + if (addr >= l->l_addr && !match || match->l_addr < l->l_addr) + match = l; + + if (match) + { + /* We know ADDRESS lies within MATCH if in any shared object. + Make sure it isn't past the end of MATCH's segments. */ + size_t n = match->l_phnum; + do + --n; + while (match->l_phdr[n].p_type != PT_LOAD); + if (addr >= (match->l_addr + + match->l_phdr[n].p_vaddr + match->l_phdr[n].p_memsz)) + /* Off the end of the highest-addressed shared object. */ + return 0; + } + else + return 0; + + /* Now we know what object the address lies in. */ + info->dli_fname = match->l_name; + info->dli_fbase = (void *) match->l_addr; + + symtab = ((void *) match->l_addr + match->l_info[DT_SYMTAB]->d_un.d_ptr); + strtab = ((void *) match->l_addr + match->l_info[DT_STRTAB]->d_un.d_ptr); + + /* We assume that the string table follows the symbol table, because + there is no way in ELF to know the size of the dynamic symbol table!! */ + for (matchsym = NULL; (void *) symtab < (void *) strtab; ++symtab) + if (addr >= match->l_addr + symtab->st_value && !matchsym || + matchsym->st_value < symtab->st_value && + ELFW(ST_BIND) (symtab->st_info) == STB_GLOBAL || + ELFW(ST_BIND) (symtab->st_info) == STB_WEAK) + matchsym = symtab; + + if (matchsym) + { + /* We found a symbol close by. Fill in its name and exact address. */ + info->dli_sname = strtab + matchsym->st_name; + info->dli_saddr = (void *) (match->l_addr + matchsym->st_value); + } + else + { + /* No symbol matches. We return only the containing object. */ + info->dli_sname = NULL; + info->dli_saddr = NULL; + } + + return 1; +} diff --git a/elf/dl-runtime.c b/elf/dl-runtime.c index e7132ed..3f09d72 100644 --- a/elf/dl-runtime.c +++ b/elf/dl-runtime.c @@ -70,37 +70,16 @@ _dl_object_relocation_scope (struct link_map *l) #include "dynamic-link.h" -/* Figure out the right type, Rel or Rela. */ -#define elf_machine_rel 1 -#define elf_machine_rela 2 -#if elf_machine_relplt == elf_machine_rel -# define PLTREL ElfW(Rel) -#elif elf_machine_relplt == elf_machine_rela -# define PLTREL ElfW(Rela) +#if !defined ELF_MACHINE_NO_RELA || ELF_MACHINE_NO_REL +# define PLTREL ElfW(Rela) #else -# error "dl-machine.h bug: elf_machine_relplt not rel or rela" +# define PLTREL ElfW(Rel) #endif -#undef elf_machine_rel -#undef elf_machine_rela #ifndef VERSYMIDX # define VERSYMIDX(sym) (DT_NUM + DT_PROCNUM + DT_VERSIONTAGIDX (sym)) #endif -#ifndef ELF_FIXUP_RETURN_VALUE -#define ELF_FIXUP_RETURN_VALUE(map, result) (result) -#endif - -/* We need to define the function as a local symbol so that the reference - in the trampoline code will be a local PC-relative call. Tell the - compiler not to worry that the function appears not to be called. */ - -static ElfW(Addr) fixup ( -#ifdef ELF_MACHINE_RUNTIME_FIXUP_ARGS - ELF_MACHINE_RUNTIME_FIXUP_ARGS, -#endif - struct link_map *l, ElfW(Word) reloc_offset) - __attribute__ ((unused)); /* This function is called through a special trampoline from the PLT the first time each PLT entry is called. We must perform the relocation @@ -109,7 +88,7 @@ static ElfW(Addr) fixup ( to that address. Future calls will bounce directly from the PLT to the function. */ -static ElfW(Addr) +static ElfW(Addr) __attribute__ ((unused)) fixup ( #ifdef ELF_MACHINE_RUNTIME_FIXUP_ARGS ELF_MACHINE_RUNTIME_FIXUP_ARGS, @@ -124,57 +103,63 @@ fixup ( const PLTREL *const reloc = (const void *) (l->l_addr + l->l_info[DT_JMPREL]->d_un.d_ptr + reloc_offset); - ElfW(Addr) *const rel_addr = (ElfW(Addr) *)(l->l_addr + reloc->r_offset); + const ElfW(Sym) *sym = &symtab[ELFW(R_SYM) (reloc->r_info)]; + void *const rel_addr = (void *)(l->l_addr + reloc->r_offset); + ElfW(Addr) value; /* Set up the scope to find symbols referenced by this object. */ struct link_map **scope = _dl_object_relocation_scope (l); - { - const struct r_found_version *here_version; - - /* This macro is used as a callback from the elf_machine_relplt code. */ -#define RESOLVE(ref, version, flags) \ - ((version) != NULL && (version)->hash != 0 \ - ? _dl_lookup_versioned_symbol (strtab + (*ref)->st_name, (ref), scope, \ - l->l_name, (version), (flags)) \ - : _dl_lookup_symbol (strtab + (*ref)->st_name, (ref), scope, \ - l->l_name, (flags))) -#include "dynamic-link.h" + /* Sanity check that we're really looking at a PLT relocation. */ + assert (ELFW(R_TYPE)(reloc->r_info) == ELF_MACHINE_JMP_SLOT); - /* Perform the specified relocation. */ - if (l->l_info[VERSYMIDX (DT_VERSYM)]) + /* Look up the target symbol. */ + switch (l->l_info[VERSYMIDX (DT_VERSYM)] != NULL) + { + default: { - const ElfW(Half) *version = - (const ElfW(Half) *) (l->l_addr + - l->l_info[VERSYMIDX (DT_VERSYM)]->d_un.d_ptr); - ElfW(Half) ndx = version[ELFW(R_SYM) (reloc->r_info)]; - - here_version = &l->l_versions[ndx]; + const ElfW(Half) *vernum = (const ElfW(Half) *) + (l->l_addr + l->l_info[VERSYMIDX (DT_VERSYM)]->d_un.d_ptr); + ElfW(Half) ndx = vernum[ELFW(R_SYM) (reloc->r_info)]; + const struct r_found_version *version = &l->l_versions[ndx]; + + if (version->hash != 0) + { + value = _dl_lookup_versioned_symbol(strtab + sym->st_name, + &sym, scope, l->l_name, + version, ELF_MACHINE_JMP_SLOT); + break; + } } - else - here_version = NULL; + case 0: + value = _dl_lookup_symbol (strtab + sym->st_name, &sym, scope, + l->l_name, ELF_MACHINE_JMP_SLOT); + } + + /* Currently value contains the base load address of the object + that defines sym. Now add in the symbol offset. */ + value = (sym ? value + sym->st_value : 0); + + /* And now the relocation addend. */ +#ifndef ELF_MACHINE_NO_RELA + if (l->l_info[DT_PLTRELSZ]->d_un.d_val == sizeof (ElfW(Rela))) + value += reloc->r_addend; +#elif ELF_MACHINE_NO_REL + value += reloc->r_addend; +#endif - elf_machine_relplt (l, reloc, &symtab[ELFW(R_SYM) (reloc->r_info)], - here_version, (void *) rel_addr); - } + /* Finally, fix up the plt itself. */ + elf_machine_fixup_plt (l, reloc, rel_addr, value); *_dl_global_scope_end = NULL; - /* Return the address that was written by the relocation. */ - return ELF_FIXUP_RETURN_VALUE(l, *rel_addr); + return value; } #ifndef PROF -static ElfW(Addr) -profile_fixup ( -#ifdef ELF_MACHINE_RUNTIME_FIXUP_ARGS - ELF_MACHINE_RUNTIME_FIXUP_ARGS, -#endif - struct link_map *l, ElfW(Word) reloc_offset, ElfW(Addr) retaddr) - __attribute__ ((unused)); -static ElfW(Addr) +static ElfW(Addr) __attribute__ ((unused)) profile_fixup ( #ifdef ELF_MACHINE_RUNTIME_FIXUP_ARGS ELF_MACHINE_RUNTIME_FIXUP_ARGS, @@ -182,6 +167,7 @@ profile_fixup ( struct link_map *l, ElfW(Word) reloc_offset, ElfW(Addr) retaddr) { void (*mcount_fct) (ElfW(Addr), ElfW(Addr)) = _dl_mcount; + const ElfW(Sym) *const symtab = (const ElfW(Sym) *) (l->l_addr + l->l_info[DT_SYMTAB]->d_un.d_ptr); const char *strtab = @@ -190,47 +176,57 @@ profile_fixup ( const PLTREL *const reloc = (const void *) (l->l_addr + l->l_info[DT_JMPREL]->d_un.d_ptr + reloc_offset); - ElfW(Addr) result; + const ElfW(Sym) *sym = &symtab[ELFW(R_SYM) (reloc->r_info)]; + ElfW(Addr) value; /* Set up the scope to find symbols referenced by this object. */ struct link_map **scope = _dl_object_relocation_scope (l); - { - const struct r_found_version *here_version; + /* Sanity check that we're really looking at a PLT relocation. */ + assert (ELFW(R_TYPE)(reloc->r_info) == ELF_MACHINE_JMP_SLOT); - /* This macro is used as a callback from the elf_machine_relplt code. */ -#define RESOLVE(ref, version, flags) \ - ((version) != NULL && (version)->hash != 0 \ - ? _dl_lookup_versioned_symbol (strtab + (*ref)->st_name, (ref), scope, \ - l->l_name, (version), (flags)) \ - : _dl_lookup_symbol (strtab + (*ref)->st_name, (ref), scope, \ - l->l_name, (flags))) -#include "dynamic-link.h" - - /* Perform the specified relocation. */ - if (l->l_info[VERSYMIDX (DT_VERSYM)]) + /* Look up the target symbol. */ + switch (l->l_info[VERSYMIDX (DT_VERSYM)] != NULL) + { + default: { - const ElfW(Half) *version = - (const ElfW(Half) *) (l->l_addr + - l->l_info[VERSYMIDX (DT_VERSYM)]->d_un.d_ptr); - ElfW(Half) ndx = version[ELFW(R_SYM) (reloc->r_info)]; - - here_version = &l->l_versions[ndx]; + const ElfW(Half) *vernum = (const ElfW(Half) *) + (l->l_addr + l->l_info[VERSYMIDX (DT_VERSYM)]->d_un.d_ptr); + ElfW(Half) ndx = vernum[ELFW(R_SYM) (reloc->r_info)]; + const struct r_found_version *version = &l->l_versions[ndx]; + + if (version->hash != 0) + { + value = _dl_lookup_versioned_symbol(strtab + sym->st_name, + &sym, scope, l->l_name, + version, ELF_MACHINE_JMP_SLOT); + break; + } } - else - here_version = NULL; + case 0: + value = _dl_lookup_symbol (strtab + sym->st_name, &sym, scope, + l->l_name, ELF_MACHINE_JMP_SLOT); + } + + /* Currently value contains the base load address of the object + that defines sym. Now add in the symbol offset. */ + value = (sym ? value + sym->st_value : 0); - elf_machine_relplt (l, reloc, &symtab[ELFW(R_SYM) (reloc->r_info)], - here_version, (void *) &result); - } + /* And now the relocation addend. */ +#ifndef ELF_MACHINE_NO_RELA + if (l->l_info[DT_PLTRELSZ]->d_un.d_val == sizeof (ElfW(Rela))) + value += reloc->r_addend; +#elif ELF_MACHINE_NO_REL + value += reloc->r_addend; +#endif *_dl_global_scope_end = NULL; - (*mcount_fct) (retaddr, ELF_FIXUP_RETURN_VALUE (l, result)); + (*mcount_fct) (retaddr, value); - /* Return the address that was written by the relocation. */ - return ELF_FIXUP_RETURN_VALUE (l, result); + return value; } -#endif + +#endif /* PROF */ /* This macro is defined in dl-machine.h to define the entry point called diff --git a/elf/dladdr.c b/elf/dladdr.c index 59e9783..d82a9e7 100644 --- a/elf/dladdr.c +++ b/elf/dladdr.c @@ -1,5 +1,5 @@ -/* dladdr -- Locate the shared object symbol nearest a given address. - Copyright (C) 1996 Free Software Foundation, Inc. +/* Locate the shared object symbol nearest a given address. + Copyright (C) 1996, 1997 Free Software Foundation, Inc. This file is part of the GNU C Library. The GNU C Library is free software; you can redistribute it and/or @@ -23,63 +23,7 @@ int -dladdr (void *address, Dl_info *info) +dladdr (const void *address, Dl_info *info) { - const ElfW(Addr) addr = (ElfW(Addr)) address; - struct link_map *l, *match; - const ElfW(Sym) *symtab, *matchsym; - const char *strtab; - - /* Find the highest-addressed object that ADDRESS is not below. */ - match = NULL; - for (l = _dl_loaded; l; l = l->l_next) - if (addr >= l->l_addr && !match || match->l_addr < l->l_addr) - match = l; - - if (match) - { - /* We know ADDRESS lies within MATCH if in any shared object. - Make sure it isn't past the end of MATCH's segments. */ - size_t n = match->l_phnum; - do - --n; - while (match->l_phdr[n].p_type != PT_LOAD); - if (addr >= (match->l_addr + - match->l_phdr[n].p_vaddr + match->l_phdr[n].p_memsz)) - /* Off the end of the highest-addressed shared object. */ - return 0; - } - else - return 0; - - /* Now we know what object the address lies in. */ - info->dli_fname = match->l_name; - info->dli_fbase = (void *) match->l_addr; - - symtab = ((void *) match->l_addr + match->l_info[DT_SYMTAB]->d_un.d_ptr); - strtab = ((void *) match->l_addr + match->l_info[DT_STRTAB]->d_un.d_ptr); - - /* We assume that the string table follows the symbol table, because - there is no way in ELF to know the size of the dynamic symbol table!! */ - for (matchsym = NULL; (void *) symtab < (void *) strtab; ++symtab) - if (addr >= match->l_addr + symtab->st_value && !matchsym || - matchsym->st_value < symtab->st_value && - ELFW(ST_BIND) (symtab->st_info) == STB_GLOBAL || - ELFW(ST_BIND) (symtab->st_info) == STB_WEAK) - matchsym = symtab; - - if (matchsym) - { - /* We found a symbol close by. Fill in its name and exact address. */ - info->dli_sname = strtab + matchsym->st_name; - info->dli_saddr = (void *) (match->l_addr + matchsym->st_value); - } - else - { - /* No symbol matches. We return only the containing object. */ - info->dli_sname = NULL; - info->dli_saddr = NULL; - } - - return 1; + return _dl_addr (address, info); } diff --git a/elf/dlfcn.h b/elf/dlfcn.h index 9db5fb4..825b484 100644 --- a/elf/dlfcn.h +++ b/elf/dlfcn.h @@ -68,7 +68,7 @@ typedef struct __const char *dli_sname; /* Name of nearest symbol. */ void *dli_saddr; /* Exact value of nearest symbol. */ } Dl_info; -extern int dladdr __P ((void *__address, Dl_info *__info)); +extern int dladdr __P ((const void *__address, Dl_info *__info)); __END_DECLS @@ -27,6 +27,7 @@ #include <stddef.h> #include <elf.h> +#include <dlfcn.h> __BEGIN_DECLS @@ -358,6 +359,9 @@ extern ElfW(Addr) _dl_lookup_versioned_symbol_skip (const char *undef, const struct r_found_version *version, struct link_map *skip_this); +/* Locate shared object containing the given address. */ +extern int _dl_addr (const void *address, Dl_info *info); + /* Look up symbol NAME in MAP's scope and return its run-time address. */ extern ElfW(Addr) _dl_symbol_value (struct link_map *map, const char *name); @@ -671,7 +671,7 @@ of this helper program; chances are you did not intend to run this program.\n", ElfW(Addr) loadbase = _dl_lookup_symbol (_dl_argv[i], &ref, &_dl_default_scope[2], "argument", - ELF_MACHINE_RELOC_NOPLT); + ELF_MACHINE_JMP_SLOT); char buf[20], *bp; buf[sizeof buf - 1] = '\0'; bp = _itoa (ref->st_value, &buf[sizeof buf - 1], 16, 0); |