hppa_reloc.c revision 1.49 1 1.49 skrll /* $NetBSD: hppa_reloc.c,v 1.49 2022/05/30 17:06:34 skrll 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 1.49 skrll __RCSID("$NetBSD: hppa_reloc.c,v 1.49 2022/05/30 17:06:34 skrll 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 1.49 skrll void _rtld_set_dp(Elf_Addr *);
56 1.1 fredette
57 1.1 fredette /*
58 1.24 skrll * It is possible for the compiler to emit relocations for unaligned data.
59 1.24 skrll * We handle this situation with these inlines.
60 1.24 skrll */
61 1.24 skrll #define RELOC_ALIGNED_P(x) \
62 1.24 skrll (((uintptr_t)(x) & (sizeof(void *) - 1)) == 0)
63 1.24 skrll
64 1.24 skrll static inline Elf_Addr
65 1.24 skrll load_ptr(void *where)
66 1.24 skrll {
67 1.24 skrll if (__predict_true(RELOC_ALIGNED_P(where)))
68 1.24 skrll return *(Elf_Addr *)where;
69 1.24 skrll else {
70 1.24 skrll Elf_Addr res;
71 1.24 skrll
72 1.24 skrll (void)memcpy(&res, where, sizeof(res));
73 1.24 skrll return res;
74 1.24 skrll }
75 1.24 skrll }
76 1.24 skrll
77 1.24 skrll static inline void
78 1.24 skrll store_ptr(void *where, Elf_Addr val)
79 1.24 skrll {
80 1.24 skrll if (__predict_true(RELOC_ALIGNED_P(where)))
81 1.24 skrll *(Elf_Addr *)where = val;
82 1.24 skrll else
83 1.24 skrll (void)memcpy(where, &val, sizeof(val));
84 1.24 skrll }
85 1.24 skrll
86 1.42 skrll static __inline void
87 1.42 skrll fdc(void *addr)
88 1.42 skrll {
89 1.42 skrll __asm volatile("fdc %%r0(%%sr0, %0)" : : "r" (addr));
90 1.42 skrll }
91 1.42 skrll
92 1.42 skrll static __inline void
93 1.46 skrll fic(void *addr)
94 1.46 skrll {
95 1.42 skrll __asm volatile("fic %%r0(%%sr0,%0)" : : "r" (addr));
96 1.46 skrll }
97 1.42 skrll
98 1.42 skrll static __inline void
99 1.42 skrll sync(void)
100 1.42 skrll {
101 1.42 skrll __asm volatile("sync" : : : "memory");
102 1.42 skrll }
103 1.42 skrll
104 1.42 skrll #define PLT_STUB_MAGIC1 0x00c0ffee
105 1.42 skrll #define PLT_STUB_MAGIC2 0xdeadbeef
106 1.42 skrll
107 1.42 skrll #define PLT_STUB_INSN1 0x0e801081 /* ldw 0(%r20), %r1 */
108 1.42 skrll #define PLT_STUB_INSN2 0xe820c000 /* bv %r0(%r1) */
109 1.42 skrll
110 1.24 skrll /*
111 1.34 skrll * In the runtime architecture (ABI), PLABEL function pointers are
112 1.34 skrll * distinguished from normal function pointers by having the next-least-
113 1.34 skrll * significant bit set. (This bit is referred to as the L field in HP
114 1.34 skrll * documentation). The $$dyncall millicode is aware of this.
115 1.1 fredette */
116 1.1 fredette #define RTLD_MAKE_PLABEL(plabel) (((Elf_Addr)(plabel)) | (1 << 1))
117 1.1 fredette #define RTLD_IS_PLABEL(addr) (((Elf_Addr)(addr)) & (1 << 1))
118 1.1 fredette #define RTLD_GET_PLABEL(addr) ((hppa_plabel *) (((Elf_Addr)addr) & ~3))
119 1.1 fredette
120 1.1 fredette /*
121 1.1 fredette * This is the PLABEL structure. The function PC and
122 1.1 fredette * shared linkage members must come first, as they are
123 1.1 fredette * the actual PLABEL.
124 1.1 fredette */
125 1.1 fredette typedef struct _hppa_plabel {
126 1.1 fredette Elf_Addr hppa_plabel_pc;
127 1.1 fredette Elf_Addr hppa_plabel_sl;
128 1.1 fredette SLIST_ENTRY(_hppa_plabel) hppa_plabel_next;
129 1.1 fredette } hppa_plabel;
130 1.1 fredette
131 1.1 fredette /*
132 1.46 skrll * For now allocated PLABEL structures are tracked on a
133 1.1 fredette * singly linked list. This maybe should be revisited.
134 1.1 fredette */
135 1.1 fredette static SLIST_HEAD(hppa_plabel_head, _hppa_plabel) hppa_plabel_list
136 1.1 fredette = SLIST_HEAD_INITIALIZER(hppa_plabel_list);
137 1.1 fredette
138 1.1 fredette /*
139 1.1 fredette * Because I'm hesitant to use NEW while relocating self,
140 1.1 fredette * this is a small pool of preallocated PLABELs.
141 1.1 fredette */
142 1.40 chs #define HPPA_PLABEL_PRE (32)
143 1.1 fredette static hppa_plabel hppa_plabel_pre[HPPA_PLABEL_PRE];
144 1.1 fredette static int hppa_plabel_pre_next = 0;
145 1.1 fredette
146 1.20 skrll void _rtld_relocate_nonplt_self(Elf_Dyn *, Elf_Addr);
147 1.20 skrll int _rtld_relocate_plt_objects(const Obj_Entry *);
148 1.25 skrll static inline int _rtld_relocate_plt_object(const Obj_Entry *,
149 1.25 skrll const Elf_Rela *, Elf_Addr *);
150 1.25 skrll
151 1.1 fredette /*
152 1.1 fredette * This bootstraps the dynamic linker by relocating its GOT.
153 1.1 fredette * On the hppa, unlike on other architectures, static strings
154 1.1 fredette * are found through the GOT. Static strings are essential
155 1.46 skrll * for RTLD_DEBUG, and I suspect they're used early even when
156 1.1 fredette * !defined(RTLD_DEBUG), making relocating the GOT essential.
157 1.1 fredette *
158 1.1 fredette * It gets worse. Relocating the GOT doesn't mean just walking
159 1.1 fredette * it and adding the relocbase to all of the entries. You must
160 1.46 skrll * find and use the GOT relocations, since those RELA relocations
161 1.46 skrll * have the necessary addends - the GOT comes initialized as
162 1.1 fredette * zeroes.
163 1.1 fredette */
164 1.1 fredette void
165 1.20 skrll _rtld_relocate_nonplt_self(Elf_Dyn *dynp, Elf_Addr relocbase)
166 1.1 fredette {
167 1.1 fredette const Elf_Rela *relafirst, *rela, *relalim;
168 1.22 chs Elf_Addr relasz;
169 1.24 skrll void *where;
170 1.20 skrll Elf_Addr *pltgot;
171 1.20 skrll const Elf_Rela *plabel_relocs[HPPA_PLABEL_PRE];
172 1.20 skrll int nplabel_relocs = 0;
173 1.20 skrll int i;
174 1.20 skrll const Elf_Sym *symtab, *sym;
175 1.20 skrll unsigned long symnum;
176 1.20 skrll hppa_plabel *plabel;
177 1.1 fredette
178 1.22 chs /*
179 1.22 chs * Process the DYNAMIC section, looking for the non-PLT relocations.
180 1.46 skrll */
181 1.1 fredette relafirst = NULL;
182 1.22 chs relasz = 0;
183 1.22 chs symtab = NULL;
184 1.22 chs pltgot = NULL;
185 1.1 fredette for (; dynp->d_tag != DT_NULL; ++dynp) {
186 1.1 fredette switch (dynp->d_tag) {
187 1.1 fredette
188 1.1 fredette case DT_RELA:
189 1.1 fredette relafirst = (const Elf_Rela *)
190 1.1 fredette (relocbase + dynp->d_un.d_ptr);
191 1.1 fredette break;
192 1.1 fredette
193 1.1 fredette case DT_RELASZ:
194 1.1 fredette relasz = dynp->d_un.d_val;
195 1.1 fredette break;
196 1.20 skrll
197 1.20 skrll case DT_SYMTAB:
198 1.20 skrll symtab = (const Elf_Sym *)
199 1.20 skrll (relocbase + dynp->d_un.d_ptr);
200 1.20 skrll break;
201 1.20 skrll
202 1.20 skrll case DT_PLTGOT:
203 1.20 skrll pltgot = (Elf_Addr *)
204 1.20 skrll (relocbase + dynp->d_un.d_ptr);
205 1.35 skrll break;
206 1.1 fredette }
207 1.1 fredette }
208 1.28 mjf relalim = (const Elf_Rela *)((const char *)relafirst + relasz);
209 1.1 fredette
210 1.18 skrll for (rela = relafirst; rela < relalim; rela++) {
211 1.20 skrll symnum = ELF_R_SYM(rela->r_info);
212 1.24 skrll where = (void *)(relocbase + rela->r_offset);
213 1.20 skrll
214 1.20 skrll switch (ELF_R_TYPE(rela->r_info)) {
215 1.20 skrll case R_TYPE(DIR32):
216 1.20 skrll if (symnum == 0)
217 1.46 skrll store_ptr(where,
218 1.24 skrll relocbase + rela->r_addend);
219 1.20 skrll else {
220 1.20 skrll sym = symtab + symnum;
221 1.46 skrll store_ptr(where,
222 1.24 skrll relocbase + rela->r_addend + sym->st_value);
223 1.20 skrll }
224 1.20 skrll break;
225 1.20 skrll
226 1.20 skrll case R_TYPE(PLABEL32):
227 1.20 skrll /*
228 1.20 skrll * PLABEL32 relocation processing is done in two phases
229 1.20 skrll *
230 1.20 skrll * i) local function relocations (symbol number == 0)
231 1.20 skrll * can be resolved immediately.
232 1.20 skrll *
233 1.20 skrll * ii) external function relocations are deferred until
234 1.20 skrll * we finish all other relocations so that global
235 1.20 skrll * data isn't accessed until all other non-PLT
236 1.20 skrll * relocations have been done.
237 1.20 skrll */
238 1.20 skrll if (symnum == 0)
239 1.46 skrll *((Elf_Addr *)where) =
240 1.20 skrll relocbase + rela->r_addend;
241 1.20 skrll else
242 1.20 skrll plabel_relocs[nplabel_relocs++] = rela;
243 1.20 skrll break;
244 1.20 skrll
245 1.20 skrll default:
246 1.20 skrll break;
247 1.20 skrll }
248 1.1 fredette }
249 1.1 fredette
250 1.20 skrll assert(nplabel_relocs < HPPA_PLABEL_PRE);
251 1.20 skrll for (i = 0; i < nplabel_relocs; i++) {
252 1.20 skrll rela = plabel_relocs[i];
253 1.24 skrll where = (void *)(relocbase + rela->r_offset);
254 1.20 skrll sym = symtab + ELF_R_SYM(rela->r_info);
255 1.46 skrll
256 1.20 skrll plabel = &hppa_plabel_pre[hppa_plabel_pre_next++];
257 1.20 skrll
258 1.35 skrll plabel->hppa_plabel_pc = (Elf_Addr)
259 1.20 skrll (relocbase + sym->st_value + rela->r_addend);
260 1.35 skrll plabel->hppa_plabel_sl = (Elf_Addr)pltgot;
261 1.20 skrll
262 1.35 skrll SLIST_INSERT_HEAD(&hppa_plabel_list, plabel, hppa_plabel_next);
263 1.20 skrll *((Elf_Addr *)where) = (Elf_Addr)(RTLD_MAKE_PLABEL(plabel));
264 1.20 skrll }
265 1.46 skrll
266 1.1 fredette #if defined(RTLD_DEBUG_HPPA)
267 1.18 skrll for (rela = relafirst; rela < relalim; rela++) {
268 1.24 skrll where = (void *)(relocbase + rela->r_offset);
269 1.20 skrll
270 1.20 skrll switch (ELF_R_TYPE(rela->r_info)) {
271 1.20 skrll case R_TYPE(DIR32):
272 1.20 skrll hdbg(("DIR32 rela @%p(%p) -> %p(%p)\n",
273 1.1 fredette (void *)rela->r_offset,
274 1.1 fredette (void *)where,
275 1.1 fredette (void *)rela->r_addend,
276 1.20 skrll (void *)*((Elf_Addr *)where) ));
277 1.20 skrll break;
278 1.20 skrll
279 1.20 skrll case R_TYPE(PLABEL32):
280 1.20 skrll symnum = ELF_R_SYM(rela->r_info);
281 1.20 skrll if (symnum == 0) {
282 1.20 skrll hdbg(("PLABEL rela @%p(%p) -> %p(%p)\n",
283 1.20 skrll (void *)rela->r_offset,
284 1.20 skrll (void *)where,
285 1.20 skrll (void *)rela->r_addend,
286 1.20 skrll (void *)*((Elf_Addr *)where) ));
287 1.20 skrll } else {
288 1.20 skrll sym = symtab + symnum;
289 1.20 skrll
290 1.20 skrll hdbg(("PLABEL32 rela @%p(%p), symnum=%ld(%p) -> %p(%p)\n",
291 1.20 skrll (void *)rela->r_offset,
292 1.20 skrll (void *)where,
293 1.20 skrll symnum,
294 1.20 skrll (void *)sym->st_value,
295 1.20 skrll (void *)rela->r_addend,
296 1.20 skrll (void *)*((Elf_Addr *)where) ));
297 1.20 skrll }
298 1.20 skrll break;
299 1.20 skrll default:
300 1.20 skrll hdbg(("rela XXX reloc\n"));
301 1.20 skrll break;
302 1.20 skrll }
303 1.1 fredette }
304 1.1 fredette #endif /* RTLD_DEBUG_HPPA */
305 1.1 fredette }
306 1.1 fredette
307 1.1 fredette /*
308 1.46 skrll * This allocates a PLABEL. If called with a non-NULL def, the
309 1.1 fredette * plabel is for the function associated with that definition
310 1.46 skrll * in the defining object defobj, plus the given addend. If
311 1.1 fredette * called with a NULL def, the plabel is for the function at
312 1.1 fredette * the (unrelocated) address in addend in the object defobj.
313 1.1 fredette */
314 1.1 fredette Elf_Addr
315 1.1 fredette _rtld_function_descriptor_alloc(const Obj_Entry *defobj, const Elf_Sym *def,
316 1.1 fredette Elf_Addr addend)
317 1.1 fredette {
318 1.1 fredette Elf_Addr func_pc, func_sl;
319 1.1 fredette hppa_plabel *plabel;
320 1.1 fredette
321 1.1 fredette if (def != NULL) {
322 1.46 skrll
323 1.1 fredette /*
324 1.1 fredette * We assume that symbols of type STT_NOTYPE
325 1.1 fredette * are undefined. Return NULL for these.
326 1.1 fredette */
327 1.1 fredette if (ELF_ST_TYPE(def->st_info) == STT_NOTYPE)
328 1.1 fredette return (Elf_Addr)NULL;
329 1.1 fredette
330 1.1 fredette /* Otherwise assert that this symbol must be a function. */
331 1.1 fredette assert(ELF_ST_TYPE(def->st_info) == STT_FUNC);
332 1.1 fredette
333 1.46 skrll func_pc = (Elf_Addr)(defobj->relocbase + def->st_value +
334 1.1 fredette addend);
335 1.1 fredette } else
336 1.1 fredette func_pc = (Elf_Addr)(defobj->relocbase + addend);
337 1.1 fredette
338 1.1 fredette /*
339 1.1 fredette * Search the existing PLABELs for one matching
340 1.1 fredette * this function. If there is one, return it.
341 1.1 fredette */
342 1.20 skrll func_sl = (Elf_Addr)(defobj->pltgot);
343 1.1 fredette SLIST_FOREACH(plabel, &hppa_plabel_list, hppa_plabel_next)
344 1.1 fredette if (plabel->hppa_plabel_pc == func_pc &&
345 1.1 fredette plabel->hppa_plabel_sl == func_sl)
346 1.1 fredette return RTLD_MAKE_PLABEL(plabel);
347 1.1 fredette
348 1.1 fredette /*
349 1.1 fredette * Once we've used up the preallocated set, we start
350 1.1 fredette * using NEW to allocate plabels.
351 1.1 fredette */
352 1.1 fredette if (hppa_plabel_pre_next < HPPA_PLABEL_PRE)
353 1.1 fredette plabel = &hppa_plabel_pre[hppa_plabel_pre_next++];
354 1.1 fredette else {
355 1.1 fredette plabel = NEW(hppa_plabel);
356 1.1 fredette if (plabel == NULL)
357 1.1 fredette return (Elf_Addr)-1;
358 1.1 fredette }
359 1.1 fredette
360 1.1 fredette /* Fill the new entry and insert it on the list. */
361 1.1 fredette plabel->hppa_plabel_pc = func_pc;
362 1.1 fredette plabel->hppa_plabel_sl = func_sl;
363 1.1 fredette SLIST_INSERT_HEAD(&hppa_plabel_list, plabel, hppa_plabel_next);
364 1.1 fredette
365 1.1 fredette return RTLD_MAKE_PLABEL(plabel);
366 1.1 fredette }
367 1.1 fredette
368 1.1 fredette /*
369 1.1 fredette * If a pointer is a PLABEL, this unwraps it.
370 1.1 fredette */
371 1.1 fredette const void *
372 1.1 fredette _rtld_function_descriptor_function(const void *addr)
373 1.1 fredette {
374 1.46 skrll return (RTLD_IS_PLABEL(addr) ?
375 1.1 fredette (const void *) RTLD_GET_PLABEL(addr)->hppa_plabel_pc :
376 1.1 fredette addr);
377 1.1 fredette }
378 1.1 fredette
379 1.2 mycroft /* This sets up an object's GOT. */
380 1.2 mycroft void
381 1.2 mycroft _rtld_setup_pltgot(const Obj_Entry *obj)
382 1.2 mycroft {
383 1.42 skrll Elf_Word *got = obj->pltgot;
384 1.42 skrll
385 1.42 skrll assert(got[-2] == PLT_STUB_MAGIC1);
386 1.42 skrll assert(got[-1] == PLT_STUB_MAGIC2);
387 1.46 skrll
388 1.42 skrll __rtld_setup_hppa_pltgot(obj, got);
389 1.42 skrll
390 1.42 skrll fdc(&got[-2]);
391 1.42 skrll fdc(&got[-1]);
392 1.42 skrll fdc(&got[1]);
393 1.42 skrll sync();
394 1.42 skrll fic(&got[-2]);
395 1.42 skrll fic(&got[-1]);
396 1.42 skrll fic(&got[1]);
397 1.42 skrll sync();
398 1.42 skrll
399 1.42 skrll /*
400 1.42 skrll * libc makes use of %t1 (%r22) to pass errno values to __cerror. Fixup
401 1.42 skrll * the PLT stub to not use %r22.
402 1.42 skrll */
403 1.42 skrll got[-7] = PLT_STUB_INSN1;
404 1.42 skrll got[-6] = PLT_STUB_INSN2;
405 1.42 skrll fdc(&got[-7]);
406 1.42 skrll fdc(&got[-6]);
407 1.42 skrll sync();
408 1.42 skrll fic(&got[-7]);
409 1.42 skrll fic(&got[-6]);
410 1.42 skrll sync();
411 1.4 mycroft }
412 1.4 mycroft
413 1.4 mycroft int
414 1.33 joerg _rtld_relocate_nonplt_objects(Obj_Entry *obj)
415 1.4 mycroft {
416 1.5 mycroft const Elf_Rela *rela;
417 1.44 joerg const Elf_Sym *def = NULL;
418 1.44 joerg const Obj_Entry *defobj = NULL;
419 1.44 joerg unsigned long last_symnum = ULONG_MAX;
420 1.5 mycroft
421 1.49 skrll /*
422 1.49 skrll * This will be done by the crt0 code, but make sure it's set
423 1.49 skrll * early so that symbols overridden by the non-pic binary
424 1.49 skrll * get the right DP value.
425 1.49 skrll */
426 1.49 skrll if (obj->mainprog) {
427 1.49 skrll hdbg(("setting DP to %p", obj->pltgot));
428 1.49 skrll _rtld_set_dp(obj->pltgot);
429 1.49 skrll }
430 1.49 skrll
431 1.5 mycroft for (rela = obj->rela; rela < obj->relalim; rela++) {
432 1.5 mycroft Elf_Addr *where;
433 1.5 mycroft Elf_Addr tmp;
434 1.5 mycroft
435 1.5 mycroft where = (Elf_Addr *)(obj->relocbase + rela->r_offset);
436 1.5 mycroft
437 1.47 skrll unsigned long symnum = ELF_R_SYM(rela->r_info);
438 1.44 joerg /* First, handle DIR32 and PLABEL32 without symbol. */
439 1.47 skrll if (symnum == 0) {
440 1.44 joerg switch (ELF_R_TYPE(rela->r_info)) {
441 1.44 joerg default:
442 1.44 joerg break;
443 1.44 joerg case R_TYPE(DIR32):
444 1.5 mycroft tmp = (Elf_Addr)(obj->relocbase +
445 1.5 mycroft rela->r_addend);
446 1.5 mycroft
447 1.24 skrll if (load_ptr(where) != tmp)
448 1.24 skrll store_ptr(where, tmp);
449 1.20 skrll rdbg(("DIR32 in %s --> %p", obj->path,
450 1.24 skrll (void *)load_ptr(where)));
451 1.44 joerg continue;
452 1.44 joerg case R_TYPE(PLABEL32):
453 1.5 mycroft /*
454 1.5 mycroft * This is a PLABEL for a static function, and
455 1.5 mycroft * the dynamic linker has both allocated a PLT
456 1.5 mycroft * entry for this function and told us where it
457 1.5 mycroft * is. We can safely use the PLT entry as the
458 1.5 mycroft * PLABEL because there should be no other
459 1.5 mycroft * PLABEL reloc referencing this function.
460 1.5 mycroft * This object should also have an IPLT
461 1.5 mycroft * relocation to initialize the PLT entry.
462 1.5 mycroft *
463 1.5 mycroft * The dynamic linker should also have ensured
464 1.5 mycroft * that the addend has the
465 1.5 mycroft * next-least-significant bit set; the
466 1.5 mycroft * $$dyncall millicode uses this to distinguish
467 1.5 mycroft * a PLABEL pointer from a plain function
468 1.5 mycroft * pointer.
469 1.5 mycroft */
470 1.19 skrll tmp = (Elf_Addr)
471 1.19 skrll (obj->relocbase + rela->r_addend);
472 1.5 mycroft
473 1.5 mycroft if (*where != tmp)
474 1.5 mycroft *where = tmp;
475 1.14 mycroft rdbg(("PLABEL32 in %s --> %p", obj->path,
476 1.14 mycroft (void *)*where));
477 1.44 joerg continue;
478 1.44 joerg }
479 1.44 joerg }
480 1.44 joerg
481 1.44 joerg switch (ELF_R_TYPE(rela->r_info)) {
482 1.44 joerg case R_TYPE(DIR32):
483 1.44 joerg case R_TYPE(PLABEL32):
484 1.44 joerg case R_TYPE(COPY):
485 1.44 joerg case R_TYPE(TLS_TPREL32):
486 1.44 joerg case R_TYPE(TLS_DTPMOD32):
487 1.44 joerg case R_TYPE(TLS_DTPOFF32):
488 1.44 joerg if (last_symnum != symnum) {
489 1.44 joerg last_symnum = symnum;
490 1.44 joerg if (ELF_R_TYPE(rela->r_info) == R_TYPE(DIR32)) {
491 1.44 joerg /*
492 1.44 joerg * DIR32 relocation against local
493 1.44 joerg * symbols are special...
494 1.44 joerg */
495 1.44 joerg def = obj->symtab + symnum;
496 1.44 joerg defobj = obj;
497 1.44 joerg if (def->st_name == 0)
498 1.44 joerg break;
499 1.44 joerg }
500 1.44 joerg def = _rtld_find_symdef(symnum, obj, &defobj,
501 1.44 joerg false);
502 1.44 joerg if (def == NULL)
503 1.44 joerg return -1;
504 1.5 mycroft }
505 1.5 mycroft break;
506 1.44 joerg default:
507 1.44 joerg break;
508 1.44 joerg }
509 1.44 joerg
510 1.44 joerg switch (ELF_R_TYPE(rela->r_info)) {
511 1.44 joerg case R_TYPE(NONE):
512 1.44 joerg break;
513 1.44 joerg
514 1.44 joerg case R_TYPE(DIR32):
515 1.44 joerg tmp = (Elf_Addr)(defobj->relocbase +
516 1.44 joerg def->st_value + rela->r_addend);
517 1.44 joerg
518 1.44 joerg if (load_ptr(where) != tmp)
519 1.44 joerg store_ptr(where, tmp);
520 1.44 joerg rdbg(("DIR32 %s in %s --> %p in %s",
521 1.44 joerg obj->strtab + obj->symtab[symnum].st_name,
522 1.44 joerg obj->path, (void *)load_ptr(where),
523 1.44 joerg defobj->path));
524 1.44 joerg break;
525 1.44 joerg
526 1.44 joerg case R_TYPE(PLABEL32):
527 1.44 joerg tmp = _rtld_function_descriptor_alloc(defobj,
528 1.44 joerg def, rela->r_addend);
529 1.44 joerg if (tmp == (Elf_Addr)-1)
530 1.44 joerg return -1;
531 1.44 joerg
532 1.44 joerg if (*where != tmp)
533 1.44 joerg *where = tmp;
534 1.44 joerg rdbg(("PLABEL32 %s in %s --> %p in %s",
535 1.44 joerg obj->strtab + obj->symtab[symnum].st_name,
536 1.44 joerg obj->path, (void *)*where, defobj->path));
537 1.44 joerg break;
538 1.4 mycroft
539 1.5 mycroft case R_TYPE(COPY):
540 1.4 mycroft /*
541 1.5 mycroft * These are deferred until all other relocations have
542 1.5 mycroft * been done. All we do here is make sure that the
543 1.5 mycroft * COPY relocation is not in a shared library. They
544 1.5 mycroft * are allowed only in executable files.
545 1.4 mycroft */
546 1.10 mycroft if (obj->isdynamic) {
547 1.5 mycroft _rtld_error(
548 1.5 mycroft "%s: Unexpected R_COPY relocation in shared library",
549 1.5 mycroft obj->path);
550 1.4 mycroft return -1;
551 1.5 mycroft }
552 1.14 mycroft rdbg(("COPY (avoid in main)"));
553 1.5 mycroft break;
554 1.4 mycroft
555 1.38 skrll case R_TYPE(TLS_TPREL32):
556 1.38 skrll if (!defobj->tls_done && _rtld_tls_offset_allocate(obj))
557 1.38 skrll return -1;
558 1.38 skrll
559 1.41 skrll *where = (Elf_Addr)(defobj->tlsoffset + def->st_value +
560 1.38 skrll rela->r_addend + sizeof(struct tls_tcb));
561 1.38 skrll
562 1.38 skrll rdbg(("TPREL32 %s in %s --> %p in %s",
563 1.38 skrll obj->strtab + obj->symtab[symnum].st_name,
564 1.38 skrll obj->path, (void *)*where, defobj->path));
565 1.38 skrll break;
566 1.38 skrll
567 1.36 skrll case R_TYPE(TLS_DTPMOD32):
568 1.36 skrll *where = (Elf_Addr)(defobj->tlsindex);
569 1.36 skrll
570 1.36 skrll rdbg(("TLS_DTPMOD32 %s in %s --> %p",
571 1.36 skrll obj->strtab + obj->symtab[symnum].st_name,
572 1.36 skrll obj->path, (void *)*where));
573 1.36 skrll
574 1.36 skrll break;
575 1.36 skrll
576 1.36 skrll case R_TYPE(TLS_DTPOFF32):
577 1.36 skrll *where = (Elf_Addr)(def->st_value);
578 1.36 skrll
579 1.36 skrll rdbg(("TLS_DTPOFF32 %s in %s --> %p",
580 1.36 skrll obj->strtab + obj->symtab[symnum].st_name,
581 1.36 skrll obj->path, (void *)*where));
582 1.36 skrll
583 1.36 skrll break;
584 1.36 skrll
585 1.5 mycroft default:
586 1.14 mycroft rdbg(("sym = %lu, type = %lu, offset = %p, "
587 1.5 mycroft "addend = %p, contents = %p, symbol = %s",
588 1.6 mycroft symnum, (u_long)ELF_R_TYPE(rela->r_info),
589 1.5 mycroft (void *)rela->r_offset, (void *)rela->r_addend,
590 1.24 skrll (void *)load_ptr(where),
591 1.6 mycroft obj->strtab + obj->symtab[symnum].st_name));
592 1.5 mycroft _rtld_error("%s: Unsupported relocation type %ld "
593 1.29 jmmv "in non-PLT relocations",
594 1.5 mycroft obj->path, (u_long) ELF_R_TYPE(rela->r_info));
595 1.4 mycroft return -1;
596 1.4 mycroft }
597 1.8 mycroft }
598 1.8 mycroft return 0;
599 1.8 mycroft }
600 1.8 mycroft
601 1.8 mycroft int
602 1.45 joerg _rtld_relocate_plt_lazy(Obj_Entry *obj)
603 1.8 mycroft {
604 1.8 mycroft const Elf_Rela *rela;
605 1.8 mycroft
606 1.8 mycroft for (rela = obj->pltrela; rela < obj->pltrelalim; rela++) {
607 1.8 mycroft Elf_Addr *where = (Elf_Addr *)(obj->relocbase + rela->r_offset);
608 1.8 mycroft Elf_Addr func_pc, func_sl;
609 1.8 mycroft
610 1.8 mycroft assert(ELF_R_TYPE(rela->r_info) == R_TYPE(IPLT));
611 1.8 mycroft
612 1.8 mycroft /*
613 1.8 mycroft * If this is an IPLT reloc for a static function,
614 1.8 mycroft * fully resolve the PLT entry now.
615 1.8 mycroft */
616 1.8 mycroft if (ELF_R_SYM(rela->r_info) == 0) {
617 1.8 mycroft func_pc = (Elf_Addr)(obj->relocbase + rela->r_addend);
618 1.20 skrll func_sl = (Elf_Addr)(obj->pltgot);
619 1.8 mycroft }
620 1.8 mycroft
621 1.8 mycroft /*
622 1.8 mycroft * Otherwise set up for lazy binding.
623 1.8 mycroft */
624 1.8 mycroft else {
625 1.8 mycroft /*
626 1.8 mycroft * This function pointer points to the PLT
627 1.8 mycroft * stub added by the linker, and instead of
628 1.8 mycroft * a shared linkage value, we stash this
629 1.8 mycroft * relocation's offset. The PLT stub has
630 1.8 mycroft * already been set up to transfer to
631 1.8 mycroft * _rtld_bind_start.
632 1.8 mycroft */
633 1.20 skrll func_pc = ((Elf_Addr)(obj->pltgot)) - 16;
634 1.19 skrll func_sl = (Elf_Addr)
635 1.28 mjf ((const char *)rela - (const char *)(obj->pltrela));
636 1.8 mycroft }
637 1.20 skrll rdbg(("lazy bind %s(%p) --> old=(%p,%p) new=(%p,%p)",
638 1.20 skrll obj->path,
639 1.20 skrll (void *)where,
640 1.46 skrll (void *)where[0], (void *)where[1],
641 1.20 skrll (void *)func_pc, (void *)func_sl));
642 1.8 mycroft
643 1.8 mycroft /*
644 1.8 mycroft * Fill this PLT entry and return.
645 1.8 mycroft */
646 1.8 mycroft where[0] = func_pc;
647 1.8 mycroft where[1] = func_sl;
648 1.4 mycroft }
649 1.4 mycroft return 0;
650 1.1 fredette }
651 1.20 skrll
652 1.25 skrll static inline int
653 1.34 skrll _rtld_relocate_plt_object(const Obj_Entry *obj, const Elf_Rela *rela,
654 1.34 skrll Elf_Addr *tp)
655 1.20 skrll {
656 1.20 skrll Elf_Word *where = (Elf_Word *)(obj->relocbase + rela->r_offset);
657 1.20 skrll const Elf_Sym *def;
658 1.20 skrll const Obj_Entry *defobj;
659 1.20 skrll Elf_Addr func_pc, func_sl;
660 1.31 christos unsigned long info = rela->r_info;
661 1.20 skrll
662 1.31 christos assert(ELF_R_TYPE(info) == R_TYPE(IPLT));
663 1.20 skrll
664 1.31 christos if (ELF_R_SYM(info) == 0) {
665 1.25 skrll func_pc = (Elf_Addr)(obj->relocbase + rela->r_addend);
666 1.25 skrll func_sl = (Elf_Addr)(obj->pltgot);
667 1.25 skrll } else {
668 1.31 christos def = _rtld_find_plt_symdef(ELF_R_SYM(info), obj, &defobj,
669 1.31 christos tp != NULL);
670 1.31 christos if (__predict_false(def == NULL))
671 1.25 skrll return -1;
672 1.31 christos if (__predict_false(def == &_rtld_sym_zero))
673 1.31 christos return 0;
674 1.20 skrll
675 1.43 joerg if (ELF_ST_TYPE(def->st_info) == STT_GNU_IFUNC) {
676 1.43 joerg if (tp == NULL)
677 1.43 joerg return 0;
678 1.43 joerg Elf_Addr ptr = _rtld_resolve_ifunc(defobj, def);
679 1.43 joerg assert(RTLD_IS_PLABEL(ptr));
680 1.43 joerg hppa_plabel *label = RTLD_GET_PLABEL(ptr);
681 1.43 joerg func_pc = label->hppa_plabel_pc;
682 1.43 joerg func_sl = label->hppa_plabel_sl;
683 1.43 joerg } else {
684 1.43 joerg func_pc = (Elf_Addr)(defobj->relocbase + def->st_value +
685 1.43 joerg rela->r_addend);
686 1.43 joerg func_sl = (Elf_Addr)(defobj->pltgot);
687 1.43 joerg }
688 1.20 skrll
689 1.25 skrll rdbg(("bind now/fixup in %s --> old=(%p,%p) new=(%p,%p)",
690 1.25 skrll defobj->strtab + def->st_name,
691 1.46 skrll (void *)where[0], (void *)where[1],
692 1.25 skrll (void *)func_pc, (void *)func_sl));
693 1.25 skrll }
694 1.20 skrll /*
695 1.20 skrll * Fill this PLT entry and return.
696 1.20 skrll */
697 1.20 skrll if (where[0] != func_pc)
698 1.20 skrll where[0] = func_pc;
699 1.20 skrll if (where[1] != func_sl)
700 1.20 skrll where[1] = func_sl;
701 1.20 skrll
702 1.25 skrll if (tp)
703 1.25 skrll *tp = (Elf_Addr)where;
704 1.25 skrll
705 1.25 skrll return 0;
706 1.25 skrll }
707 1.25 skrll
708 1.25 skrll caddr_t
709 1.25 skrll _rtld_bind(const Obj_Entry *obj, Elf_Word reloff)
710 1.25 skrll {
711 1.28 mjf const Elf_Rela *rela;
712 1.32 skrll Elf_Addr new_value = 0; /* XXX gcc */
713 1.25 skrll int err;
714 1.25 skrll
715 1.28 mjf rela = (const Elf_Rela *)((const char *)obj->pltrela + reloff);
716 1.46 skrll
717 1.25 skrll assert(ELF_R_SYM(rela->r_info) != 0);
718 1.25 skrll
719 1.39 joerg _rtld_shared_enter();
720 1.46 skrll err = _rtld_relocate_plt_object(obj, rela, &new_value);
721 1.31 christos if (err)
722 1.25 skrll _rtld_die();
723 1.39 joerg _rtld_shared_exit();
724 1.25 skrll
725 1.25 skrll return (caddr_t)new_value;
726 1.20 skrll }
727 1.20 skrll
728 1.20 skrll int
729 1.20 skrll _rtld_relocate_plt_objects(const Obj_Entry *obj)
730 1.20 skrll {
731 1.25 skrll const Elf_Rela *rela = obj->pltrela;
732 1.46 skrll
733 1.25 skrll for (; rela < obj->pltrelalim; rela++) {
734 1.25 skrll if (_rtld_relocate_plt_object(obj, rela, NULL) < 0)
735 1.25 skrll return -1;
736 1.20 skrll }
737 1.20 skrll return 0;
738 1.20 skrll }
739 1.43 joerg
740 1.43 joerg Elf_Addr
741 1.43 joerg _rtld_call_function_addr(const Obj_Entry *obj, Elf_Addr ptr)
742 1.43 joerg {
743 1.43 joerg volatile hppa_plabel plabel;
744 1.43 joerg Elf_Addr (*f)(void);
745 1.43 joerg
746 1.43 joerg plabel.hppa_plabel_pc = (Elf_Addr)ptr;
747 1.43 joerg plabel.hppa_plabel_sl = (Elf_Addr)(obj->pltgot);
748 1.43 joerg f = (Elf_Addr (*)(void))RTLD_MAKE_PLABEL(&plabel);
749 1.43 joerg
750 1.43 joerg return f();
751 1.43 joerg }
752