diff --git a/libexec/rtld-elf/aarch64/reloc.c b/libexec/rtld-elf/aarch64/reloc.c index 2ca13d8c7c86..eb355ea6ff50 100644 --- a/libexec/rtld-elf/aarch64/reloc.c +++ b/libexec/rtld-elf/aarch64/reloc.c @@ -218,6 +218,9 @@ reloc_plt(Obj_Entry *obj) case R_AARCH64_TLSDESC: reloc_tlsdesc(obj, rela, where); break; + case R_AARCH64_IRELATIVE: + obj->irelative = true; + break; default: _rtld_error("Unknown relocation type %u in PLT", (unsigned int)ELF_R_TYPE(rela->r_info)); @@ -242,19 +245,22 @@ reloc_jmpslots(Obj_Entry *obj, int flags, RtldLockState *lockstate) relalim = (const Elf_Rela *)((char *)obj->pltrela + obj->pltrelasize); for (rela = obj->pltrela; rela < relalim; rela++) { - Elf_Addr *where; + Elf_Addr *where, target; where = (Elf_Addr *)(obj->relocbase + rela->r_offset); switch(ELF_R_TYPE(rela->r_info)) { case R_AARCH64_JUMP_SLOT: def = find_symdef(ELF_R_SYM(rela->r_info), obj, &defobj, SYMLOOK_IN_PLT | flags, NULL, lockstate); - if (def == NULL) { - dbg("reloc_jmpslots: sym not found"); + if (def == NULL) return (-1); + if (ELF_ST_TYPE(def->st_info) == STT_GNU_IFUNC) { + obj->gnu_ifunc = true; + continue; } - - *where = (Elf_Addr)(defobj->relocbase + def->st_value); + target = (Elf_Addr)(defobj->relocbase + def->st_value); + reloc_jmpslot(where, target, defobj, obj, + (const Elf_Rel *)rela); break; case R_AARCH64_TLSDESC: if (ELF_R_SYM(rela->r_info) != 0) { @@ -277,8 +283,24 @@ reloc_jmpslots(Obj_Entry *obj, int flags, RtldLockState *lockstate) int reloc_iresolve(Obj_Entry *obj, struct Struct_RtldLockState *lockstate) { + const Elf_Rela *relalim; + const Elf_Rela *rela; + Elf_Addr *where, target, *ptr; - /* XXX not implemented */ + if (!obj->irelative) + return (0); + relalim = (const Elf_Rela *)((char *)obj->pltrela + obj->pltrelasize); + for (rela = obj->pltrela; rela < relalim; rela++) { + if (ELF_R_TYPE(rela->r_info) == R_AARCH64_IRELATIVE) { + ptr = (Elf_Addr *)(obj->relocbase + rela->r_addend); + where = (Elf_Addr *)(obj->relocbase + rela->r_offset); + lock_release(rtld_bind_lock, lockstate); + target = call_ifunc_resolver(ptr); + wlock_acquire(rtld_bind_lock, lockstate); + *where = target; + } + } + obj->irelative = false; return (0); } @@ -286,8 +308,32 @@ int reloc_gnu_ifunc(Obj_Entry *obj, int flags, struct Struct_RtldLockState *lockstate) { + const Elf_Rela *relalim; + const Elf_Rela *rela; + Elf_Addr *where, target; + const Elf_Sym *def; + const Obj_Entry *defobj; - /* XXX not implemented */ + if (!obj->gnu_ifunc) + return (0); + relalim = (const Elf_Rela *)((char *)obj->pltrela + obj->pltrelasize); + for (rela = obj->pltrela; rela < relalim; rela++) { + if (ELF_R_TYPE(rela->r_info) == R_AARCH64_JUMP_SLOT) { + where = (Elf_Addr *)(obj->relocbase + rela->r_offset); + def = find_symdef(ELF_R_SYM(rela->r_info), obj, &defobj, + SYMLOOK_IN_PLT | flags, NULL, lockstate); + if (def == NULL) + return (-1); + if (ELF_ST_TYPE(def->st_info) != STT_GNU_IFUNC) + continue; + lock_release(rtld_bind_lock, lockstate); + target = (Elf_Addr)rtld_resolve_ifunc(defobj, def); + wlock_acquire(rtld_bind_lock, lockstate); + reloc_jmpslot(where, target, defobj, obj, + (const Elf_Rel *)rela); + } + } + obj->gnu_ifunc = false; return (0); } @@ -296,7 +342,8 @@ reloc_jmpslot(Elf_Addr *where, Elf_Addr target, const Obj_Entry *defobj, const Obj_Entry *obj, const Elf_Rel *rel) { - assert(ELF_R_TYPE(rel->r_info) == R_AARCH64_JUMP_SLOT); + assert(ELF_R_TYPE(rel->r_info) == R_AARCH64_JUMP_SLOT || + ELF_R_TYPE(rel->r_info) == R_AARCH64_IRELATIVE); if (*where != target && !ld_bind_not) *where = target; @@ -327,12 +374,7 @@ reloc_non_plt(Obj_Entry *obj, Obj_Entry *obj_rtld, int flags, const Elf_Rela *rela; const Elf_Sym *def; SymCache *cache; - Elf_Addr *where; - unsigned long symnum; - - if ((flags & SYMLOOK_IFUNC) != 0) - /* XXX not implemented */ - return (0); + Elf_Addr *where, symval; /* * The dynamic loader may be called from a thread, we have @@ -346,19 +388,62 @@ reloc_non_plt(Obj_Entry *obj, Obj_Entry *obj_rtld, int flags, relalim = (const Elf_Rela *)((caddr_t)obj->rela + obj->relasize); for (rela = obj->rela; rela < relalim; rela++) { + /* + * First, resolve symbol for relocations which + * reference symbols. + */ + switch (ELF_R_TYPE(rela->r_info)) { + case R_AARCH64_ABS64: + case R_AARCH64_GLOB_DAT: + case R_AARCH64_TLS_TPREL64: + def = find_symdef(ELF_R_SYM(rela->r_info), obj, + &defobj, flags, cache, lockstate); + if (def == NULL) + return (-1); + /* + * If symbol is IFUNC, only perform relocation + * when caller allowed it by passing + * SYMLOOK_IFUNC flag. Skip the relocations + * otherwise. + * + * Also error out in case IFUNC relocations + * are specified for TLS, which cannot be + * usefully interpreted. + */ + if (ELF_ST_TYPE(def->st_info) == STT_GNU_IFUNC) { + switch (ELF_R_TYPE(rela->r_info)) { + case R_AARCH64_ABS64: + case R_AARCH64_GLOB_DAT: + if ((flags & SYMLOOK_IFUNC) == 0) { + obj->non_plt_gnu_ifunc = true; + continue; + } + symval = (Elf_Addr)rtld_resolve_ifunc( + defobj, def); + break; + default: + _rtld_error("%s: IFUNC for TLS reloc", + obj->path); + return (-1); + } + } else { + if ((flags & SYMLOOK_IFUNC) != 0) + continue; + symval = (Elf_Addr)defobj->relocbase + + def->st_value; + } + break; + default: + if ((flags & SYMLOOK_IFUNC) != 0) + continue; + } + where = (Elf_Addr *)(obj->relocbase + rela->r_offset); - symnum = ELF_R_SYM(rela->r_info); switch (ELF_R_TYPE(rela->r_info)) { case R_AARCH64_ABS64: case R_AARCH64_GLOB_DAT: - def = find_symdef(symnum, obj, &defobj, flags, cache, - lockstate); - if (def == NULL) - return (-1); - - *where = (Elf_Addr)defobj->relocbase + def->st_value + - rela->r_addend; + *where = symval + rela->r_addend; break; case R_AARCH64_COPY: /* @@ -377,11 +462,6 @@ reloc_non_plt(Obj_Entry *obj, Obj_Entry *obj_rtld, int flags, reloc_tlsdesc(obj, rela, where); break; case R_AARCH64_TLS_TPREL64: - def = find_symdef(symnum, obj, &defobj, flags, cache, - lockstate); - if (def == NULL) - return (-1); - /* * We lazily allocate offsets for static TLS as we * see the first relocation that references the diff --git a/libexec/rtld-elf/aarch64/rtld_machdep.h b/libexec/rtld-elf/aarch64/rtld_machdep.h index 9ff53d900aaa..9cc0f2443318 100644 --- a/libexec/rtld-elf/aarch64/rtld_machdep.h +++ b/libexec/rtld-elf/aarch64/rtld_machdep.h @@ -59,8 +59,16 @@ Elf_Addr reloc_jmpslot(Elf_Addr *where, Elf_Addr target, #define call_init_pointer(obj, target) \ (((InitArrFunc)(target))(main_argc, main_argv, environ)) +/* + * Pass zeros into the ifunc resolver so we can change them later. The first + * 8 arguments on arm64 are passed in registers so make them known values + * if we decide to use them later. Because of this ifunc resolvers can assume + * no arguments are passeed in, and if this changes later will be able to + * compare the argument with 0 to see if it is set. + */ #define call_ifunc_resolver(ptr) \ - (((Elf_Addr (*)(void))ptr)()) + (((Elf_Addr (*)(uint64_t, uint64_t, uint64_t, uint64_t, uint64_t, \ + uint64_t, uint64_t, uint64_t))ptr)(0, 0, 0, 0, 0, 0, 0, 0)) #define round(size, align) \ (((size) + (align) - 1) & ~((align) - 1))