diff options
Diffstat (limited to 'elf/dl-runtime.c')
| -rw-r--r-- | elf/dl-runtime.c | 174 |
1 files changed, 85 insertions, 89 deletions
diff --git a/elf/dl-runtime.c b/elf/dl-runtime.c index e7132ed832..3f09d72c32 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 |