1 /* $NetBSD: mdreloc.c,v 1.37 2014/08/31 20:06:22 joerg Exp $ */
5 __RCSID("$NetBSD: mdreloc.c,v 1.37 2014/08/31 20:06:22 joerg Exp $");
9 #include <sys/ucontext.h>
14 void _rtld_bind_start(void);
15 void _rtld_relocate_nonplt_self(Elf_Dyn
*, Elf_Addr
);
16 caddr_t
_rtld_bind(const Obj_Entry
*, Elf_Word
);
19 _rtld_setup_pltgot(const Obj_Entry
*obj
)
21 obj
->pltgot
[1] = (Elf_Addr
) obj
;
22 obj
->pltgot
[2] = (Elf_Addr
) &_rtld_bind_start
;
26 _rtld_relocate_nonplt_self(Elf_Dyn
*dynp
, Elf_Addr relocbase
)
28 const Elf_Rel
*rel
= 0, *rellim
;
32 for (; dynp
->d_tag
!= DT_NULL
; dynp
++) {
33 switch (dynp
->d_tag
) {
35 rel
= (const Elf_Rel
*)(relocbase
+ dynp
->d_un
.d_ptr
);
38 relsz
= dynp
->d_un
.d_val
;
42 if (rel
== 0 || relsz
== 0)
44 rellim
= (const Elf_Rel
*)((const uint8_t *)rel
+ relsz
);
45 for (; rel
< rellim
; rel
++) {
46 where
= (Elf_Addr
*)(relocbase
+ rel
->r_offset
);
47 *where
+= (Elf_Addr
)relocbase
;
52 _rtld_relocate_nonplt_objects(Obj_Entry
*obj
)
57 for (rel
= obj
->rel
; rel
< obj
->rellim
; rel
++) {
60 const Obj_Entry
*defobj
;
64 where
= (Elf_Addr
*)(obj
->relocbase
+ rel
->r_offset
);
65 symnum
= ELF_R_SYM(rel
->r_info
);
67 switch (ELF_R_TYPE(rel
->r_info
)) {
71 #if 1 /* XXX should not occur */
73 def
= _rtld_find_symdef(symnum
, obj
, &defobj
, false);
76 target
= (Elf_Addr
)(defobj
->relocbase
+ def
->st_value
);
78 *where
+= target
- (Elf_Addr
)where
;
79 rdbg(("PC32 %s in %s --> %p in %s",
80 obj
->strtab
+ obj
->symtab
[symnum
].st_name
,
81 obj
->path
, (void *)*where
, defobj
->path
));
87 case R_TYPE(GLOB_DAT
):
88 def
= _rtld_find_symdef(symnum
, obj
, &defobj
, false);
91 target
= (Elf_Addr
)(defobj
->relocbase
+ def
->st_value
);
93 tmp
= target
+ *where
;
96 rdbg(("32/GLOB_DAT %s in %s --> %p in %s",
97 obj
->strtab
+ obj
->symtab
[symnum
].st_name
,
98 obj
->path
, (void *)*where
, defobj
->path
));
101 case R_TYPE(RELATIVE
):
102 *where
+= (Elf_Addr
)obj
->relocbase
;
103 rdbg(("RELATIVE in %s --> %p", obj
->path
,
109 * These are deferred until all other relocations have
110 * been done. All we do here is make sure that the
111 * COPY relocation is not in a shared library. They
112 * are allowed only in executable files.
114 if (obj
->isdynamic
) {
116 "%s: Unexpected R_COPY relocation in shared library",
120 rdbg(("COPY (avoid in main)"));
123 #if defined(__minix) && defined(__HAVE_TLS_VARIANT_I) || defined(__HAVE_TLS_VARIANT_II)
124 case R_TYPE(TLS_TPOFF
):
125 def
= _rtld_find_symdef(symnum
, obj
, &defobj
, false);
129 if (!defobj
->tls_done
&&
130 _rtld_tls_offset_allocate(obj
))
133 *where
+= (Elf_Addr
)(def
->st_value
- defobj
->tlsoffset
);
135 rdbg(("TLS_TPOFF %s in %s --> %p",
136 obj
->strtab
+ obj
->symtab
[symnum
].st_name
,
137 obj
->path
, (void *)*where
));
140 case R_TYPE(TLS_TPOFF32
):
141 def
= _rtld_find_symdef(symnum
, obj
, &defobj
, false);
145 if (!defobj
->tls_done
&&
146 _rtld_tls_offset_allocate(obj
))
149 *where
+= (Elf_Addr
)(defobj
->tlsoffset
- def
->st_value
);
150 rdbg(("TLS_TPOFF32 %s in %s --> %p",
151 obj
->strtab
+ obj
->symtab
[symnum
].st_name
,
152 obj
->path
, (void *)*where
));
155 case R_TYPE(TLS_DTPMOD32
):
156 def
= _rtld_find_symdef(symnum
, obj
, &defobj
, false);
160 *where
= (Elf_Addr
)(defobj
->tlsindex
);
162 rdbg(("TLS_DTPMOD32 %s in %s --> %p",
163 obj
->strtab
+ obj
->symtab
[symnum
].st_name
,
164 obj
->path
, (void *)*where
));
167 case R_TYPE(TLS_DTPOFF32
):
168 def
= _rtld_find_symdef(symnum
, obj
, &defobj
, false);
172 *where
= (Elf_Addr
)(def
->st_value
);
174 rdbg(("TLS_DTPOFF32 %s in %s --> %p",
175 obj
->strtab
+ obj
->symtab
[symnum
].st_name
,
176 obj
->path
, (void *)*where
));
179 #endif /* defined(__minix) && defined(__HAVE_TLS_VARIANT_I) || defined(__HAVE_TLS_VARIANT_II) */
182 rdbg(("sym = %lu, type = %lu, offset = %p, "
183 "contents = %p, symbol = %s",
184 symnum
, (u_long
)ELF_R_TYPE(rel
->r_info
),
185 (void *)rel
->r_offset
, (void *)*where
,
186 obj
->strtab
+ obj
->symtab
[symnum
].st_name
));
187 _rtld_error("%s: Unsupported relocation type %ld "
188 "in non-PLT relocations",
189 obj
->path
, (u_long
) ELF_R_TYPE(rel
->r_info
));
197 _rtld_relocate_plt_lazy(const Obj_Entry
*obj
)
204 for (rel
= obj
->pltrel
; rel
< obj
->pltrellim
; rel
++) {
205 Elf_Addr
*where
= (Elf_Addr
*)(obj
->relocbase
+ rel
->r_offset
);
207 assert(ELF_R_TYPE(rel
->r_info
) == R_TYPE(JMP_SLOT
));
209 /* Just relocate the GOT slots pointing into the PLT */
210 *where
+= (Elf_Addr
)obj
->relocbase
;
211 rdbg(("fixup !main in %s --> %p", obj
->path
, (void *)*where
));
218 _rtld_relocate_plt_object(const Obj_Entry
*obj
, const Elf_Rel
*rel
,
221 Elf_Addr
*where
= (Elf_Addr
*)(obj
->relocbase
+ rel
->r_offset
);
224 const Obj_Entry
*defobj
;
225 unsigned long info
= rel
->r_info
;
227 assert(ELF_R_TYPE(info
) == R_TYPE(JMP_SLOT
));
229 def
= _rtld_find_plt_symdef(ELF_R_SYM(info
), obj
, &defobj
, tp
!= NULL
);
230 if (__predict_false(def
== NULL
))
232 if (__predict_false(def
== &_rtld_sym_zero
))
235 if (ELF_ST_TYPE(def
->st_info
) == STT_GNU_IFUNC
) {
238 target
= _rtld_resolve_ifunc(defobj
, def
);
240 target
= (Elf_Addr
)(defobj
->relocbase
+ def
->st_value
);
243 rdbg(("bind now/fixup in %s --> old=%p new=%p",
244 defobj
->strtab
+ def
->st_name
, (void *)*where
,
246 if (*where
!= target
)
254 _rtld_bind(const Obj_Entry
*obj
, Elf_Word reloff
)
256 const Elf_Rel
*rel
= (const Elf_Rel
*)((const uint8_t *)obj
->pltrel
261 new_value
= 0; /* XXX gcc */
263 _rtld_shared_enter();
264 err
= _rtld_relocate_plt_object(obj
, rel
, &new_value
);
269 return (caddr_t
)new_value
;
273 _rtld_relocate_plt_objects(const Obj_Entry
*obj
)
278 for (rel
= obj
->pltrel
; rel
< obj
->pltrellim
; rel
++) {
279 err
= _rtld_relocate_plt_object(obj
, rel
, NULL
);
286 #if defined(__minix) && defined(__HAVE_TLS_VARIANT_I) || defined(__HAVE_TLS_VARIANT_II)
288 * i386 specific GNU variant of __tls_get_addr using register based
291 #define DTV_MAX_INDEX(dtv) ((size_t)((dtv)[-1]))
293 __dso_public
__attribute__((__regparm__(1))) void *
294 ___tls_get_addr(void *arg_
)
296 size_t *arg
= (size_t *)arg_
;
298 struct tls_tcb
*tcb
= __lwp_getprivate_fast();
299 size_t idx
= arg
[0], offset
= arg
[1];
303 if (__predict_true(idx
< DTV_MAX_INDEX(dtv
) && dtv
[idx
] != NULL
))
304 return (uint8_t *)dtv
[idx
] + offset
;
306 return _rtld_tls_get_addr(tcb
, idx
, offset
);
308 #endif /* defined(__minix) && defined(__HAVE_TLS_VARIANT_I) || defined(__HAVE_TLS_VARIANT_II) */