hppa_reloc.c revision 1.45 1 1.45 joerg /* $NetBSD: hppa_reloc.c,v 1.45 2017/08/10 19:03:26 joerg Exp $ */
2 1.1 fredette
3 1.1 fredette /*-
4 1.21 skrll * Copyright (c) 2002, 2004 The NetBSD Foundation, Inc.
5 1.1 fredette * All rights reserved.
6 1.1 fredette *
7 1.1 fredette * This code is derived from software contributed to The NetBSD Foundation
8 1.21 skrll * by Matt Fredette and Nick Hudson.
9 1.1 fredette *
10 1.1 fredette * Redistribution and use in source and binary forms, with or without
11 1.1 fredette * modification, are permitted provided that the following conditions
12 1.1 fredette * are met:
13 1.1 fredette * 1. Redistributions of source code must retain the above copyright
14 1.1 fredette * notice, this list of conditions and the following disclaimer.
15 1.1 fredette * 2. Redistributions in binary form must reproduce the above copyright
16 1.1 fredette * notice, this list of conditions and the following disclaimer in the
17 1.1 fredette * documentation and/or other materials provided with the distribution.
18 1.1 fredette *
19 1.1 fredette * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
20 1.1 fredette * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
21 1.1 fredette * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
22 1.1 fredette * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
23 1.1 fredette * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
24 1.1 fredette * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
25 1.1 fredette * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
26 1.1 fredette * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
27 1.1 fredette * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
28 1.1 fredette * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
29 1.1 fredette * POSSIBILITY OF SUCH DAMAGE.
30 1.1 fredette */
31 1.1 fredette
32 1.23 skrll #include <sys/cdefs.h>
33 1.23 skrll #ifndef lint
34 1.45 joerg __RCSID("$NetBSD: hppa_reloc.c,v 1.45 2017/08/10 19:03:26 joerg Exp $");
35 1.23 skrll #endif /* not lint */
36 1.23 skrll
37 1.1 fredette #include <stdlib.h>
38 1.1 fredette #include <sys/types.h>
39 1.1 fredette #include <sys/queue.h>
40 1.1 fredette
41 1.24 skrll #include <string.h>
42 1.24 skrll
43 1.1 fredette #include "rtld.h"
44 1.1 fredette #include "debug.h"
45 1.1 fredette
46 1.1 fredette #ifdef RTLD_DEBUG_HPPA
47 1.14 mycroft #define hdbg(x) xprintf x
48 1.1 fredette #else
49 1.1 fredette #define hdbg(x) /* nothing */
50 1.1 fredette #endif
51 1.12 mycroft
52 1.20 skrll caddr_t _rtld_bind(const Obj_Entry *, const Elf_Addr);
53 1.12 mycroft void _rtld_bind_start(void);
54 1.13 mycroft void __rtld_setup_hppa_pltgot(const Obj_Entry *, Elf_Addr *);
55 1.1 fredette
56 1.1 fredette /*
57 1.24 skrll * It is possible for the compiler to emit relocations for unaligned data.
58 1.24 skrll * We handle this situation with these inlines.
59 1.24 skrll */
60 1.24 skrll #define RELOC_ALIGNED_P(x) \
61 1.24 skrll (((uintptr_t)(x) & (sizeof(void *) - 1)) == 0)
62 1.24 skrll
63 1.24 skrll static inline Elf_Addr
64 1.24 skrll load_ptr(void *where)
65 1.24 skrll {
66 1.24 skrll if (__predict_true(RELOC_ALIGNED_P(where)))
67 1.24 skrll return *(Elf_Addr *)where;
68 1.24 skrll else {
69 1.24 skrll Elf_Addr res;
70 1.24 skrll
71 1.24 skrll (void)memcpy(&res, where, sizeof(res));
72 1.24 skrll return res;
73 1.24 skrll }
74 1.24 skrll }
75 1.24 skrll
76 1.24 skrll static inline void
77 1.24 skrll store_ptr(void *where, Elf_Addr val)
78 1.24 skrll {
79 1.24 skrll if (__predict_true(RELOC_ALIGNED_P(where)))
80 1.24 skrll *(Elf_Addr *)where = val;
81 1.24 skrll else
82 1.24 skrll (void)memcpy(where, &val, sizeof(val));
83 1.24 skrll }
84 1.24 skrll
85 1.42 skrll static __inline void
86 1.42 skrll fdc(void *addr)
87 1.42 skrll {
88 1.42 skrll __asm volatile("fdc %%r0(%%sr0, %0)" : : "r" (addr));
89 1.42 skrll }
90 1.42 skrll
91 1.42 skrll static __inline void
92 1.42 skrll fic(void *addr)
93 1.42 skrll {
94 1.42 skrll __asm volatile("fic %%r0(%%sr0,%0)" : : "r" (addr));
95 1.42 skrll }
96 1.42 skrll
97 1.42 skrll static __inline void
98 1.42 skrll sync(void)
99 1.42 skrll {
100 1.42 skrll __asm volatile("sync" : : : "memory");
101 1.42 skrll }
102 1.42 skrll
103 1.42 skrll #define PLT_STUB_MAGIC1 0x00c0ffee
104 1.42 skrll #define PLT_STUB_MAGIC2 0xdeadbeef
105 1.42 skrll
106 1.42 skrll #define PLT_STUB_INSN1 0x0e801081 /* ldw 0(%r20), %r1 */
107 1.42 skrll #define PLT_STUB_INSN2 0xe820c000 /* bv %r0(%r1) */
108 1.42 skrll
109 1.24 skrll /*
110 1.34 skrll * In the runtime architecture (ABI), PLABEL function pointers are
111 1.34 skrll * distinguished from normal function pointers by having the next-least-
112 1.34 skrll * significant bit set. (This bit is referred to as the L field in HP
113 1.34 skrll * documentation). The $$dyncall millicode is aware of this.
114 1.1 fredette */
115 1.1 fredette #define RTLD_MAKE_PLABEL(plabel) (((Elf_Addr)(plabel)) | (1 << 1))
116 1.1 fredette #define RTLD_IS_PLABEL(addr) (((Elf_Addr)(addr)) & (1 << 1))
117 1.1 fredette #define RTLD_GET_PLABEL(addr) ((hppa_plabel *) (((Elf_Addr)addr) & ~3))
118 1.1 fredette
119 1.1 fredette /*
120 1.1 fredette * This is the PLABEL structure. The function PC and
121 1.1 fredette * shared linkage members must come first, as they are
122 1.1 fredette * the actual PLABEL.
123 1.1 fredette */
124 1.1 fredette typedef struct _hppa_plabel {
125 1.1 fredette Elf_Addr hppa_plabel_pc;
126 1.1 fredette Elf_Addr hppa_plabel_sl;
127 1.1 fredette SLIST_ENTRY(_hppa_plabel) hppa_plabel_next;
128 1.1 fredette } hppa_plabel;
129 1.1 fredette
130 1.1 fredette /*
131 1.1 fredette * For now allocated PLABEL structures are tracked on a
132 1.1 fredette * singly linked list. This maybe should be revisited.
133 1.1 fredette */
134 1.1 fredette static SLIST_HEAD(hppa_plabel_head, _hppa_plabel) hppa_plabel_list
135 1.1 fredette = SLIST_HEAD_INITIALIZER(hppa_plabel_list);
136 1.1 fredette
137 1.1 fredette /*
138 1.1 fredette * Because I'm hesitant to use NEW while relocating self,
139 1.1 fredette * this is a small pool of preallocated PLABELs.
140 1.1 fredette */
141 1.40 chs #define HPPA_PLABEL_PRE (32)
142 1.1 fredette static hppa_plabel hppa_plabel_pre[HPPA_PLABEL_PRE];
143 1.1 fredette static int hppa_plabel_pre_next = 0;
144 1.1 fredette
145 1.20 skrll void _rtld_relocate_nonplt_self(Elf_Dyn *, Elf_Addr);
146 1.20 skrll int _rtld_relocate_plt_objects(const Obj_Entry *);
147 1.25 skrll static inline int _rtld_relocate_plt_object(const Obj_Entry *,
148 1.25 skrll const Elf_Rela *, Elf_Addr *);
149 1.25 skrll
150 1.1 fredette /*
151 1.1 fredette * This bootstraps the dynamic linker by relocating its GOT.
152 1.1 fredette * On the hppa, unlike on other architectures, static strings
153 1.1 fredette * are found through the GOT. Static strings are essential
154 1.1 fredette * for RTLD_DEBUG, and I suspect they're used early even when
155 1.1 fredette * !defined(RTLD_DEBUG), making relocating the GOT essential.
156 1.1 fredette *
157 1.1 fredette * It gets worse. Relocating the GOT doesn't mean just walking
158 1.1 fredette * it and adding the relocbase to all of the entries. You must
159 1.1 fredette * find and use the GOT relocations, since those RELA relocations
160 1.1 fredette * have the necessary addends - the GOT comes initialized as
161 1.1 fredette * zeroes.
162 1.1 fredette */
163 1.1 fredette void
164 1.20 skrll _rtld_relocate_nonplt_self(Elf_Dyn *dynp, Elf_Addr relocbase)
165 1.1 fredette {
166 1.1 fredette const Elf_Rela *relafirst, *rela, *relalim;
167 1.22 chs Elf_Addr relasz;
168 1.24 skrll void *where;
169 1.20 skrll Elf_Addr *pltgot;
170 1.20 skrll const Elf_Rela *plabel_relocs[HPPA_PLABEL_PRE];
171 1.20 skrll int nplabel_relocs = 0;
172 1.20 skrll int i;
173 1.20 skrll const Elf_Sym *symtab, *sym;
174 1.20 skrll unsigned long symnum;
175 1.20 skrll hppa_plabel *plabel;
176 1.1 fredette
177 1.22 chs /*
178 1.22 chs * Process the DYNAMIC section, looking for the non-PLT relocations.
179 1.1 fredette */
180 1.1 fredette relafirst = NULL;
181 1.22 chs relasz = 0;
182 1.22 chs symtab = NULL;
183 1.22 chs pltgot = NULL;
184 1.1 fredette for (; dynp->d_tag != DT_NULL; ++dynp) {
185 1.1 fredette switch (dynp->d_tag) {
186 1.1 fredette
187 1.1 fredette case DT_RELA:
188 1.1 fredette relafirst = (const Elf_Rela *)
189 1.1 fredette (relocbase + dynp->d_un.d_ptr);
190 1.1 fredette break;
191 1.1 fredette
192 1.1 fredette case DT_RELASZ:
193 1.1 fredette relasz = dynp->d_un.d_val;
194 1.1 fredette break;
195 1.20 skrll
196 1.20 skrll case DT_SYMTAB:
197 1.20 skrll symtab = (const Elf_Sym *)
198 1.20 skrll (relocbase + dynp->d_un.d_ptr);
199 1.20 skrll break;
200 1.20 skrll
201 1.20 skrll case DT_PLTGOT:
202 1.20 skrll pltgot = (Elf_Addr *)
203 1.20 skrll (relocbase + dynp->d_un.d_ptr);
204 1.35 skrll break;
205 1.1 fredette }
206 1.1 fredette }
207 1.28 mjf relalim = (const Elf_Rela *)((const char *)relafirst + relasz);
208 1.1 fredette
209 1.18 skrll for (rela = relafirst; rela < relalim; rela++) {
210 1.20 skrll symnum = ELF_R_SYM(rela->r_info);
211 1.24 skrll where = (void *)(relocbase + rela->r_offset);
212 1.20 skrll
213 1.20 skrll switch (ELF_R_TYPE(rela->r_info)) {
214 1.20 skrll case R_TYPE(DIR32):
215 1.20 skrll if (symnum == 0)
216 1.24 skrll store_ptr(where,
217 1.24 skrll relocbase + rela->r_addend);
218 1.20 skrll else {
219 1.20 skrll sym = symtab + symnum;
220 1.24 skrll store_ptr(where,
221 1.24 skrll relocbase + rela->r_addend + sym->st_value);
222 1.20 skrll }
223 1.20 skrll break;
224 1.20 skrll
225 1.20 skrll case R_TYPE(PLABEL32):
226 1.20 skrll /*
227 1.20 skrll * PLABEL32 relocation processing is done in two phases
228 1.20 skrll *
229 1.20 skrll * i) local function relocations (symbol number == 0)
230 1.20 skrll * can be resolved immediately.
231 1.20 skrll *
232 1.20 skrll * ii) external function relocations are deferred until
233 1.20 skrll * we finish all other relocations so that global
234 1.20 skrll * data isn't accessed until all other non-PLT
235 1.20 skrll * relocations have been done.
236 1.20 skrll */
237 1.20 skrll if (symnum == 0)
238 1.20 skrll *((Elf_Addr *)where) =
239 1.20 skrll relocbase + rela->r_addend;
240 1.20 skrll else
241 1.20 skrll plabel_relocs[nplabel_relocs++] = rela;
242 1.20 skrll break;
243 1.20 skrll
244 1.20 skrll default:
245 1.20 skrll break;
246 1.20 skrll }
247 1.1 fredette }
248 1.1 fredette
249 1.20 skrll assert(nplabel_relocs < HPPA_PLABEL_PRE);
250 1.20 skrll for (i = 0; i < nplabel_relocs; i++) {
251 1.20 skrll rela = plabel_relocs[i];
252 1.24 skrll where = (void *)(relocbase + rela->r_offset);
253 1.20 skrll sym = symtab + ELF_R_SYM(rela->r_info);
254 1.20 skrll
255 1.20 skrll plabel = &hppa_plabel_pre[hppa_plabel_pre_next++];
256 1.20 skrll
257 1.35 skrll plabel->hppa_plabel_pc = (Elf_Addr)
258 1.20 skrll (relocbase + sym->st_value + rela->r_addend);
259 1.35 skrll plabel->hppa_plabel_sl = (Elf_Addr)pltgot;
260 1.20 skrll
261 1.35 skrll SLIST_INSERT_HEAD(&hppa_plabel_list, plabel, hppa_plabel_next);
262 1.20 skrll *((Elf_Addr *)where) = (Elf_Addr)(RTLD_MAKE_PLABEL(plabel));
263 1.20 skrll }
264 1.20 skrll
265 1.1 fredette #if defined(RTLD_DEBUG_HPPA)
266 1.18 skrll for (rela = relafirst; rela < relalim; rela++) {
267 1.24 skrll where = (void *)(relocbase + rela->r_offset);
268 1.20 skrll
269 1.20 skrll switch (ELF_R_TYPE(rela->r_info)) {
270 1.20 skrll case R_TYPE(DIR32):
271 1.20 skrll hdbg(("DIR32 rela @%p(%p) -> %p(%p)\n",
272 1.1 fredette (void *)rela->r_offset,
273 1.1 fredette (void *)where,
274 1.1 fredette (void *)rela->r_addend,
275 1.20 skrll (void *)*((Elf_Addr *)where) ));
276 1.20 skrll break;
277 1.20 skrll
278 1.20 skrll case R_TYPE(PLABEL32):
279 1.20 skrll symnum = ELF_R_SYM(rela->r_info);
280 1.20 skrll if (symnum == 0) {
281 1.20 skrll hdbg(("PLABEL rela @%p(%p) -> %p(%p)\n",
282 1.20 skrll (void *)rela->r_offset,
283 1.20 skrll (void *)where,
284 1.20 skrll (void *)rela->r_addend,
285 1.20 skrll (void *)*((Elf_Addr *)where) ));
286 1.20 skrll } else {
287 1.20 skrll sym = symtab + symnum;
288 1.20 skrll
289 1.20 skrll hdbg(("PLABEL32 rela @%p(%p), symnum=%ld(%p) -> %p(%p)\n",
290 1.20 skrll (void *)rela->r_offset,
291 1.20 skrll (void *)where,
292 1.20 skrll symnum,
293 1.20 skrll (void *)sym->st_value,
294 1.20 skrll (void *)rela->r_addend,
295 1.20 skrll (void *)*((Elf_Addr *)where) ));
296 1.20 skrll }
297 1.20 skrll break;
298 1.20 skrll default:
299 1.20 skrll hdbg(("rela XXX reloc\n"));
300 1.20 skrll break;
301 1.20 skrll }
302 1.1 fredette }
303 1.1 fredette #endif /* RTLD_DEBUG_HPPA */
304 1.1 fredette }
305 1.1 fredette
306 1.1 fredette /*
307 1.1 fredette * This allocates a PLABEL. If called with a non-NULL def, the
308 1.1 fredette * plabel is for the function associated with that definition
309 1.1 fredette * in the defining object defobj, plus the given addend. If
310 1.1 fredette * called with a NULL def, the plabel is for the function at
311 1.1 fredette * the (unrelocated) address in addend in the object defobj.
312 1.1 fredette */
313 1.1 fredette Elf_Addr
314 1.1 fredette _rtld_function_descriptor_alloc(const Obj_Entry *defobj, const Elf_Sym *def,
315 1.1 fredette Elf_Addr addend)
316 1.1 fredette {
317 1.1 fredette Elf_Addr func_pc, func_sl;
318 1.1 fredette hppa_plabel *plabel;
319 1.1 fredette
320 1.1 fredette if (def != NULL) {
321 1.1 fredette
322 1.1 fredette /*
323 1.1 fredette * We assume that symbols of type STT_NOTYPE
324 1.1 fredette * are undefined. Return NULL for these.
325 1.1 fredette */
326 1.1 fredette if (ELF_ST_TYPE(def->st_info) == STT_NOTYPE)
327 1.1 fredette return (Elf_Addr)NULL;
328 1.1 fredette
329 1.1 fredette /* Otherwise assert that this symbol must be a function. */
330 1.1 fredette assert(ELF_ST_TYPE(def->st_info) == STT_FUNC);
331 1.1 fredette
332 1.1 fredette func_pc = (Elf_Addr)(defobj->relocbase + def->st_value +
333 1.1 fredette addend);
334 1.1 fredette } else
335 1.1 fredette func_pc = (Elf_Addr)(defobj->relocbase + addend);
336 1.1 fredette
337 1.1 fredette /*
338 1.1 fredette * Search the existing PLABELs for one matching
339 1.1 fredette * this function. If there is one, return it.
340 1.1 fredette */
341 1.20 skrll func_sl = (Elf_Addr)(defobj->pltgot);
342 1.1 fredette SLIST_FOREACH(plabel, &hppa_plabel_list, hppa_plabel_next)
343 1.1 fredette if (plabel->hppa_plabel_pc == func_pc &&
344 1.1 fredette plabel->hppa_plabel_sl == func_sl)
345 1.1 fredette return RTLD_MAKE_PLABEL(plabel);
346 1.1 fredette
347 1.1 fredette /*
348 1.1 fredette * Once we've used up the preallocated set, we start
349 1.1 fredette * using NEW to allocate plabels.
350 1.1 fredette */
351 1.1 fredette if (hppa_plabel_pre_next < HPPA_PLABEL_PRE)
352 1.1 fredette plabel = &hppa_plabel_pre[hppa_plabel_pre_next++];
353 1.1 fredette else {
354 1.1 fredette plabel = NEW(hppa_plabel);
355 1.1 fredette if (plabel == NULL)
356 1.1 fredette return (Elf_Addr)-1;
357 1.1 fredette }
358 1.1 fredette
359 1.1 fredette /* Fill the new entry and insert it on the list. */
360 1.1 fredette plabel->hppa_plabel_pc = func_pc;
361 1.1 fredette plabel->hppa_plabel_sl = func_sl;
362 1.1 fredette SLIST_INSERT_HEAD(&hppa_plabel_list, plabel, hppa_plabel_next);
363 1.1 fredette
364 1.1 fredette return RTLD_MAKE_PLABEL(plabel);
365 1.1 fredette }
366 1.1 fredette
367 1.1 fredette /*
368 1.1 fredette * If a pointer is a PLABEL, this unwraps it.
369 1.1 fredette */
370 1.1 fredette const void *
371 1.1 fredette _rtld_function_descriptor_function(const void *addr)
372 1.1 fredette {
373 1.1 fredette return (RTLD_IS_PLABEL(addr) ?
374 1.1 fredette (const void *) RTLD_GET_PLABEL(addr)->hppa_plabel_pc :
375 1.1 fredette addr);
376 1.1 fredette }
377 1.1 fredette
378 1.2 mycroft /* This sets up an object's GOT. */
379 1.2 mycroft void
380 1.2 mycroft _rtld_setup_pltgot(const Obj_Entry *obj)
381 1.2 mycroft {
382 1.42 skrll Elf_Word *got = obj->pltgot;
383 1.42 skrll
384 1.42 skrll assert(got[-2] == PLT_STUB_MAGIC1);
385 1.42 skrll assert(got[-1] == PLT_STUB_MAGIC2);
386 1.42 skrll
387 1.42 skrll __rtld_setup_hppa_pltgot(obj, got);
388 1.42 skrll
389 1.42 skrll fdc(&got[-2]);
390 1.42 skrll fdc(&got[-1]);
391 1.42 skrll fdc(&got[1]);
392 1.42 skrll sync();
393 1.42 skrll fic(&got[-2]);
394 1.42 skrll fic(&got[-1]);
395 1.42 skrll fic(&got[1]);
396 1.42 skrll sync();
397 1.42 skrll
398 1.42 skrll /*
399 1.42 skrll * libc makes use of %t1 (%r22) to pass errno values to __cerror. Fixup
400 1.42 skrll * the PLT stub to not use %r22.
401 1.42 skrll */
402 1.42 skrll got[-7] = PLT_STUB_INSN1;
403 1.42 skrll got[-6] = PLT_STUB_INSN2;
404 1.42 skrll fdc(&got[-7]);
405 1.42 skrll fdc(&got[-6]);
406 1.42 skrll sync();
407 1.42 skrll fic(&got[-7]);
408 1.42 skrll fic(&got[-6]);
409 1.42 skrll sync();
410 1.4 mycroft }
411 1.4 mycroft
412 1.4 mycroft int
413 1.33 joerg _rtld_relocate_nonplt_objects(Obj_Entry *obj)
414 1.4 mycroft {
415 1.5 mycroft const Elf_Rela *rela;
416 1.44 joerg const Elf_Sym *def = NULL;
417 1.44 joerg const Obj_Entry *defobj = NULL;
418 1.44 joerg unsigned long last_symnum = ULONG_MAX;
419 1.5 mycroft
420 1.5 mycroft for (rela = obj->rela; rela < obj->relalim; rela++) {
421 1.5 mycroft Elf_Addr *where;
422 1.5 mycroft Elf_Addr tmp;
423 1.6 mycroft unsigned long symnum;
424 1.5 mycroft
425 1.5 mycroft where = (Elf_Addr *)(obj->relocbase + rela->r_offset);
426 1.5 mycroft
427 1.44 joerg /* First, handle DIR32 and PLABEL32 without symbol. */
428 1.44 joerg if (ELF_R_SYM(rela->r_info) == 0) {
429 1.44 joerg switch (ELF_R_TYPE(rela->r_info)) {
430 1.44 joerg default:
431 1.44 joerg break;
432 1.44 joerg case R_TYPE(DIR32):
433 1.5 mycroft tmp = (Elf_Addr)(obj->relocbase +
434 1.5 mycroft rela->r_addend);
435 1.5 mycroft
436 1.24 skrll if (load_ptr(where) != tmp)
437 1.24 skrll store_ptr(where, tmp);
438 1.20 skrll rdbg(("DIR32 in %s --> %p", obj->path,
439 1.24 skrll (void *)load_ptr(where)));
440 1.44 joerg continue;
441 1.44 joerg case R_TYPE(PLABEL32):
442 1.5 mycroft /*
443 1.5 mycroft * This is a PLABEL for a static function, and
444 1.5 mycroft * the dynamic linker has both allocated a PLT
445 1.5 mycroft * entry for this function and told us where it
446 1.5 mycroft * is. We can safely use the PLT entry as the
447 1.5 mycroft * PLABEL because there should be no other
448 1.5 mycroft * PLABEL reloc referencing this function.
449 1.5 mycroft * This object should also have an IPLT
450 1.5 mycroft * relocation to initialize the PLT entry.
451 1.5 mycroft *
452 1.5 mycroft * The dynamic linker should also have ensured
453 1.5 mycroft * that the addend has the
454 1.5 mycroft * next-least-significant bit set; the
455 1.5 mycroft * $$dyncall millicode uses this to distinguish
456 1.5 mycroft * a PLABEL pointer from a plain function
457 1.5 mycroft * pointer.
458 1.5 mycroft */
459 1.19 skrll tmp = (Elf_Addr)
460 1.19 skrll (obj->relocbase + rela->r_addend);
461 1.5 mycroft
462 1.5 mycroft if (*where != tmp)
463 1.5 mycroft *where = tmp;
464 1.14 mycroft rdbg(("PLABEL32 in %s --> %p", obj->path,
465 1.14 mycroft (void *)*where));
466 1.44 joerg continue;
467 1.44 joerg }
468 1.44 joerg }
469 1.44 joerg
470 1.44 joerg switch (ELF_R_TYPE(rela->r_info)) {
471 1.44 joerg case R_TYPE(DIR32):
472 1.44 joerg case R_TYPE(PLABEL32):
473 1.44 joerg case R_TYPE(COPY):
474 1.44 joerg case R_TYPE(TLS_TPREL32):
475 1.44 joerg case R_TYPE(TLS_DTPMOD32):
476 1.44 joerg case R_TYPE(TLS_DTPOFF32):
477 1.44 joerg symnum = ELF_R_SYM(rela->r_info);
478 1.44 joerg if (last_symnum != symnum) {
479 1.44 joerg last_symnum = symnum;
480 1.44 joerg if (ELF_R_TYPE(rela->r_info) == R_TYPE(DIR32)) {
481 1.44 joerg /*
482 1.44 joerg * DIR32 relocation against local
483 1.44 joerg * symbols are special...
484 1.44 joerg */
485 1.44 joerg def = obj->symtab + symnum;
486 1.44 joerg defobj = obj;
487 1.44 joerg if (def->st_name == 0)
488 1.44 joerg break;
489 1.44 joerg }
490 1.44 joerg def = _rtld_find_symdef(symnum, obj, &defobj,
491 1.44 joerg false);
492 1.44 joerg if (def == NULL)
493 1.44 joerg return -1;
494 1.5 mycroft }
495 1.5 mycroft break;
496 1.44 joerg default:
497 1.44 joerg break;
498 1.44 joerg }
499 1.44 joerg
500 1.44 joerg switch (ELF_R_TYPE(rela->r_info)) {
501 1.44 joerg case R_TYPE(NONE):
502 1.44 joerg break;
503 1.44 joerg
504 1.44 joerg case R_TYPE(DIR32):
505 1.44 joerg tmp = (Elf_Addr)(defobj->relocbase +
506 1.44 joerg def->st_value + rela->r_addend);
507 1.44 joerg
508 1.44 joerg if (load_ptr(where) != tmp)
509 1.44 joerg store_ptr(where, tmp);
510 1.44 joerg rdbg(("DIR32 %s in %s --> %p in %s",
511 1.44 joerg obj->strtab + obj->symtab[symnum].st_name,
512 1.44 joerg obj->path, (void *)load_ptr(where),
513 1.44 joerg defobj->path));
514 1.44 joerg break;
515 1.44 joerg
516 1.44 joerg case R_TYPE(PLABEL32):
517 1.44 joerg tmp = _rtld_function_descriptor_alloc(defobj,
518 1.44 joerg def, rela->r_addend);
519 1.44 joerg if (tmp == (Elf_Addr)-1)
520 1.44 joerg return -1;
521 1.44 joerg
522 1.44 joerg if (*where != tmp)
523 1.44 joerg *where = tmp;
524 1.44 joerg rdbg(("PLABEL32 %s in %s --> %p in %s",
525 1.44 joerg obj->strtab + obj->symtab[symnum].st_name,
526 1.44 joerg obj->path, (void *)*where, defobj->path));
527 1.44 joerg break;
528 1.4 mycroft
529 1.5 mycroft case R_TYPE(COPY):
530 1.4 mycroft /*
531 1.5 mycroft * These are deferred until all other relocations have
532 1.5 mycroft * been done. All we do here is make sure that the
533 1.5 mycroft * COPY relocation is not in a shared library. They
534 1.5 mycroft * are allowed only in executable files.
535 1.4 mycroft */
536 1.10 mycroft if (obj->isdynamic) {
537 1.5 mycroft _rtld_error(
538 1.5 mycroft "%s: Unexpected R_COPY relocation in shared library",
539 1.5 mycroft obj->path);
540 1.4 mycroft return -1;
541 1.5 mycroft }
542 1.14 mycroft rdbg(("COPY (avoid in main)"));
543 1.5 mycroft break;
544 1.4 mycroft
545 1.38 skrll case R_TYPE(TLS_TPREL32):
546 1.38 skrll if (!defobj->tls_done && _rtld_tls_offset_allocate(obj))
547 1.38 skrll return -1;
548 1.38 skrll
549 1.41 skrll *where = (Elf_Addr)(defobj->tlsoffset + def->st_value +
550 1.38 skrll rela->r_addend + sizeof(struct tls_tcb));
551 1.38 skrll
552 1.38 skrll rdbg(("TPREL32 %s in %s --> %p in %s",
553 1.38 skrll obj->strtab + obj->symtab[symnum].st_name,
554 1.38 skrll obj->path, (void *)*where, defobj->path));
555 1.38 skrll break;
556 1.38 skrll
557 1.36 skrll case R_TYPE(TLS_DTPMOD32):
558 1.36 skrll *where = (Elf_Addr)(defobj->tlsindex);
559 1.36 skrll
560 1.36 skrll rdbg(("TLS_DTPMOD32 %s in %s --> %p",
561 1.36 skrll obj->strtab + obj->symtab[symnum].st_name,
562 1.36 skrll obj->path, (void *)*where));
563 1.36 skrll
564 1.36 skrll break;
565 1.36 skrll
566 1.36 skrll case R_TYPE(TLS_DTPOFF32):
567 1.36 skrll *where = (Elf_Addr)(def->st_value);
568 1.36 skrll
569 1.36 skrll rdbg(("TLS_DTPOFF32 %s in %s --> %p",
570 1.36 skrll obj->strtab + obj->symtab[symnum].st_name,
571 1.36 skrll obj->path, (void *)*where));
572 1.36 skrll
573 1.36 skrll break;
574 1.36 skrll
575 1.5 mycroft default:
576 1.14 mycroft rdbg(("sym = %lu, type = %lu, offset = %p, "
577 1.5 mycroft "addend = %p, contents = %p, symbol = %s",
578 1.6 mycroft symnum, (u_long)ELF_R_TYPE(rela->r_info),
579 1.5 mycroft (void *)rela->r_offset, (void *)rela->r_addend,
580 1.24 skrll (void *)load_ptr(where),
581 1.6 mycroft obj->strtab + obj->symtab[symnum].st_name));
582 1.5 mycroft _rtld_error("%s: Unsupported relocation type %ld "
583 1.29 jmmv "in non-PLT relocations",
584 1.5 mycroft obj->path, (u_long) ELF_R_TYPE(rela->r_info));
585 1.4 mycroft return -1;
586 1.4 mycroft }
587 1.8 mycroft }
588 1.8 mycroft return 0;
589 1.8 mycroft }
590 1.8 mycroft
591 1.8 mycroft int
592 1.45 joerg _rtld_relocate_plt_lazy(Obj_Entry *obj)
593 1.8 mycroft {
594 1.8 mycroft const Elf_Rela *rela;
595 1.8 mycroft
596 1.8 mycroft for (rela = obj->pltrela; rela < obj->pltrelalim; rela++) {
597 1.8 mycroft Elf_Addr *where = (Elf_Addr *)(obj->relocbase + rela->r_offset);
598 1.8 mycroft Elf_Addr func_pc, func_sl;
599 1.8 mycroft
600 1.8 mycroft assert(ELF_R_TYPE(rela->r_info) == R_TYPE(IPLT));
601 1.8 mycroft
602 1.8 mycroft /*
603 1.8 mycroft * If this is an IPLT reloc for a static function,
604 1.8 mycroft * fully resolve the PLT entry now.
605 1.8 mycroft */
606 1.8 mycroft if (ELF_R_SYM(rela->r_info) == 0) {
607 1.8 mycroft func_pc = (Elf_Addr)(obj->relocbase + rela->r_addend);
608 1.20 skrll func_sl = (Elf_Addr)(obj->pltgot);
609 1.8 mycroft }
610 1.8 mycroft
611 1.8 mycroft /*
612 1.8 mycroft * Otherwise set up for lazy binding.
613 1.8 mycroft */
614 1.8 mycroft else {
615 1.8 mycroft /*
616 1.8 mycroft * This function pointer points to the PLT
617 1.8 mycroft * stub added by the linker, and instead of
618 1.8 mycroft * a shared linkage value, we stash this
619 1.8 mycroft * relocation's offset. The PLT stub has
620 1.8 mycroft * already been set up to transfer to
621 1.8 mycroft * _rtld_bind_start.
622 1.8 mycroft */
623 1.20 skrll func_pc = ((Elf_Addr)(obj->pltgot)) - 16;
624 1.19 skrll func_sl = (Elf_Addr)
625 1.28 mjf ((const char *)rela - (const char *)(obj->pltrela));
626 1.8 mycroft }
627 1.20 skrll rdbg(("lazy bind %s(%p) --> old=(%p,%p) new=(%p,%p)",
628 1.20 skrll obj->path,
629 1.20 skrll (void *)where,
630 1.20 skrll (void *)where[0], (void *)where[1],
631 1.20 skrll (void *)func_pc, (void *)func_sl));
632 1.8 mycroft
633 1.8 mycroft /*
634 1.8 mycroft * Fill this PLT entry and return.
635 1.8 mycroft */
636 1.8 mycroft where[0] = func_pc;
637 1.8 mycroft where[1] = func_sl;
638 1.4 mycroft }
639 1.4 mycroft return 0;
640 1.1 fredette }
641 1.20 skrll
642 1.25 skrll static inline int
643 1.34 skrll _rtld_relocate_plt_object(const Obj_Entry *obj, const Elf_Rela *rela,
644 1.34 skrll Elf_Addr *tp)
645 1.20 skrll {
646 1.20 skrll Elf_Word *where = (Elf_Word *)(obj->relocbase + rela->r_offset);
647 1.20 skrll const Elf_Sym *def;
648 1.20 skrll const Obj_Entry *defobj;
649 1.20 skrll Elf_Addr func_pc, func_sl;
650 1.31 christos unsigned long info = rela->r_info;
651 1.20 skrll
652 1.31 christos assert(ELF_R_TYPE(info) == R_TYPE(IPLT));
653 1.20 skrll
654 1.31 christos if (ELF_R_SYM(info) == 0) {
655 1.25 skrll func_pc = (Elf_Addr)(obj->relocbase + rela->r_addend);
656 1.25 skrll func_sl = (Elf_Addr)(obj->pltgot);
657 1.25 skrll } else {
658 1.31 christos def = _rtld_find_plt_symdef(ELF_R_SYM(info), obj, &defobj,
659 1.31 christos tp != NULL);
660 1.31 christos if (__predict_false(def == NULL))
661 1.25 skrll return -1;
662 1.31 christos if (__predict_false(def == &_rtld_sym_zero))
663 1.31 christos return 0;
664 1.20 skrll
665 1.43 joerg if (ELF_ST_TYPE(def->st_info) == STT_GNU_IFUNC) {
666 1.43 joerg if (tp == NULL)
667 1.43 joerg return 0;
668 1.43 joerg Elf_Addr ptr = _rtld_resolve_ifunc(defobj, def);
669 1.43 joerg assert(RTLD_IS_PLABEL(ptr));
670 1.43 joerg hppa_plabel *label = RTLD_GET_PLABEL(ptr);
671 1.43 joerg func_pc = label->hppa_plabel_pc;
672 1.43 joerg func_sl = label->hppa_plabel_sl;
673 1.43 joerg } else {
674 1.43 joerg func_pc = (Elf_Addr)(defobj->relocbase + def->st_value +
675 1.43 joerg rela->r_addend);
676 1.43 joerg func_sl = (Elf_Addr)(defobj->pltgot);
677 1.43 joerg }
678 1.20 skrll
679 1.25 skrll rdbg(("bind now/fixup in %s --> old=(%p,%p) new=(%p,%p)",
680 1.25 skrll defobj->strtab + def->st_name,
681 1.25 skrll (void *)where[0], (void *)where[1],
682 1.25 skrll (void *)func_pc, (void *)func_sl));
683 1.25 skrll }
684 1.20 skrll /*
685 1.20 skrll * Fill this PLT entry and return.
686 1.20 skrll */
687 1.20 skrll if (where[0] != func_pc)
688 1.20 skrll where[0] = func_pc;
689 1.20 skrll if (where[1] != func_sl)
690 1.20 skrll where[1] = func_sl;
691 1.20 skrll
692 1.25 skrll if (tp)
693 1.25 skrll *tp = (Elf_Addr)where;
694 1.25 skrll
695 1.25 skrll return 0;
696 1.25 skrll }
697 1.25 skrll
698 1.25 skrll caddr_t
699 1.25 skrll _rtld_bind(const Obj_Entry *obj, Elf_Word reloff)
700 1.25 skrll {
701 1.28 mjf const Elf_Rela *rela;
702 1.32 skrll Elf_Addr new_value = 0; /* XXX gcc */
703 1.25 skrll int err;
704 1.25 skrll
705 1.28 mjf rela = (const Elf_Rela *)((const char *)obj->pltrela + reloff);
706 1.28 mjf
707 1.25 skrll assert(ELF_R_SYM(rela->r_info) != 0);
708 1.25 skrll
709 1.39 joerg _rtld_shared_enter();
710 1.25 skrll err = _rtld_relocate_plt_object(obj, rela, &new_value);
711 1.31 christos if (err)
712 1.25 skrll _rtld_die();
713 1.39 joerg _rtld_shared_exit();
714 1.25 skrll
715 1.25 skrll return (caddr_t)new_value;
716 1.20 skrll }
717 1.20 skrll
718 1.20 skrll int
719 1.20 skrll _rtld_relocate_plt_objects(const Obj_Entry *obj)
720 1.20 skrll {
721 1.25 skrll const Elf_Rela *rela = obj->pltrela;
722 1.20 skrll
723 1.25 skrll for (; rela < obj->pltrelalim; rela++) {
724 1.25 skrll if (_rtld_relocate_plt_object(obj, rela, NULL) < 0)
725 1.25 skrll return -1;
726 1.20 skrll }
727 1.20 skrll return 0;
728 1.20 skrll }
729 1.43 joerg
730 1.43 joerg void
731 1.43 joerg _rtld_call_function_void(const Obj_Entry *obj, Elf_Addr ptr)
732 1.43 joerg {
733 1.43 joerg volatile hppa_plabel plabel;
734 1.43 joerg void (*f)(void);
735 1.43 joerg
736 1.43 joerg plabel.hppa_plabel_pc = (Elf_Addr)ptr;
737 1.43 joerg plabel.hppa_plabel_sl = (Elf_Addr)(obj->pltgot);
738 1.43 joerg f = (void (*)(void))RTLD_MAKE_PLABEL(&plabel);
739 1.43 joerg
740 1.43 joerg f();
741 1.43 joerg }
742 1.43 joerg
743 1.43 joerg Elf_Addr
744 1.43 joerg _rtld_call_function_addr(const Obj_Entry *obj, Elf_Addr ptr)
745 1.43 joerg {
746 1.43 joerg volatile hppa_plabel plabel;
747 1.43 joerg Elf_Addr (*f)(void);
748 1.43 joerg
749 1.43 joerg plabel.hppa_plabel_pc = (Elf_Addr)ptr;
750 1.43 joerg plabel.hppa_plabel_sl = (Elf_Addr)(obj->pltgot);
751 1.43 joerg f = (Elf_Addr (*)(void))RTLD_MAKE_PLABEL(&plabel);
752 1.43 joerg
753 1.43 joerg return f();
754 1.43 joerg }
755