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md/raid5: correctly update sync_completed when we reach max_resync
[deliverable/linux.git] / arch / ia64 / kernel / module.c
1 /*
2 * IA-64-specific support for kernel module loader.
3 *
4 * Copyright (C) 2003 Hewlett-Packard Co
5 * David Mosberger-Tang <davidm@hpl.hp.com>
6 *
7 * Loosely based on patch by Rusty Russell.
8 */
9
10 /* relocs tested so far:
11
12 DIR64LSB
13 FPTR64LSB
14 GPREL22
15 LDXMOV
16 LDXMOV
17 LTOFF22
18 LTOFF22X
19 LTOFF22X
20 LTOFF_FPTR22
21 PCREL21B (for br.call only; br.cond is not supported out of modules!)
22 PCREL60B (for brl.cond only; brl.call is not supported for modules!)
23 PCREL64LSB
24 SECREL32LSB
25 SEGREL64LSB
26 */
27
28
29 #include <linux/kernel.h>
30 #include <linux/sched.h>
31 #include <linux/elf.h>
32 #include <linux/moduleloader.h>
33 #include <linux/string.h>
34 #include <linux/vmalloc.h>
35
36 #include <asm/patch.h>
37 #include <asm/unaligned.h>
38
39 #define ARCH_MODULE_DEBUG 0
40
41 #if ARCH_MODULE_DEBUG
42 # define DEBUGP printk
43 # define inline
44 #else
45 # define DEBUGP(fmt , a...)
46 #endif
47
48 #ifdef CONFIG_ITANIUM
49 # define USE_BRL 0
50 #else
51 # define USE_BRL 1
52 #endif
53
54 #define MAX_LTOFF ((uint64_t) (1 << 22)) /* max. allowable linkage-table offset */
55
56 /* Define some relocation helper macros/types: */
57
58 #define FORMAT_SHIFT 0
59 #define FORMAT_BITS 3
60 #define FORMAT_MASK ((1 << FORMAT_BITS) - 1)
61 #define VALUE_SHIFT 3
62 #define VALUE_BITS 5
63 #define VALUE_MASK ((1 << VALUE_BITS) - 1)
64
65 enum reloc_target_format {
66 /* direct encoded formats: */
67 RF_NONE = 0,
68 RF_INSN14 = 1,
69 RF_INSN22 = 2,
70 RF_INSN64 = 3,
71 RF_32MSB = 4,
72 RF_32LSB = 5,
73 RF_64MSB = 6,
74 RF_64LSB = 7,
75
76 /* formats that cannot be directly decoded: */
77 RF_INSN60,
78 RF_INSN21B, /* imm21 form 1 */
79 RF_INSN21M, /* imm21 form 2 */
80 RF_INSN21F /* imm21 form 3 */
81 };
82
83 enum reloc_value_formula {
84 RV_DIRECT = 4, /* S + A */
85 RV_GPREL = 5, /* @gprel(S + A) */
86 RV_LTREL = 6, /* @ltoff(S + A) */
87 RV_PLTREL = 7, /* @pltoff(S + A) */
88 RV_FPTR = 8, /* @fptr(S + A) */
89 RV_PCREL = 9, /* S + A - P */
90 RV_LTREL_FPTR = 10, /* @ltoff(@fptr(S + A)) */
91 RV_SEGREL = 11, /* @segrel(S + A) */
92 RV_SECREL = 12, /* @secrel(S + A) */
93 RV_BDREL = 13, /* BD + A */
94 RV_LTV = 14, /* S + A (like RV_DIRECT, except frozen at static link-time) */
95 RV_PCREL2 = 15, /* S + A - P */
96 RV_SPECIAL = 16, /* various (see below) */
97 RV_RSVD17 = 17,
98 RV_TPREL = 18, /* @tprel(S + A) */
99 RV_LTREL_TPREL = 19, /* @ltoff(@tprel(S + A)) */
100 RV_DTPMOD = 20, /* @dtpmod(S + A) */
101 RV_LTREL_DTPMOD = 21, /* @ltoff(@dtpmod(S + A)) */
102 RV_DTPREL = 22, /* @dtprel(S + A) */
103 RV_LTREL_DTPREL = 23, /* @ltoff(@dtprel(S + A)) */
104 RV_RSVD24 = 24,
105 RV_RSVD25 = 25,
106 RV_RSVD26 = 26,
107 RV_RSVD27 = 27
108 /* 28-31 reserved for implementation-specific purposes. */
109 };
110
111 #define N(reloc) [R_IA64_##reloc] = #reloc
112
113 static const char *reloc_name[256] = {
114 N(NONE), N(IMM14), N(IMM22), N(IMM64),
115 N(DIR32MSB), N(DIR32LSB), N(DIR64MSB), N(DIR64LSB),
116 N(GPREL22), N(GPREL64I), N(GPREL32MSB), N(GPREL32LSB),
117 N(GPREL64MSB), N(GPREL64LSB), N(LTOFF22), N(LTOFF64I),
118 N(PLTOFF22), N(PLTOFF64I), N(PLTOFF64MSB), N(PLTOFF64LSB),
119 N(FPTR64I), N(FPTR32MSB), N(FPTR32LSB), N(FPTR64MSB),
120 N(FPTR64LSB), N(PCREL60B), N(PCREL21B), N(PCREL21M),
121 N(PCREL21F), N(PCREL32MSB), N(PCREL32LSB), N(PCREL64MSB),
122 N(PCREL64LSB), N(LTOFF_FPTR22), N(LTOFF_FPTR64I), N(LTOFF_FPTR32MSB),
123 N(LTOFF_FPTR32LSB), N(LTOFF_FPTR64MSB), N(LTOFF_FPTR64LSB), N(SEGREL32MSB),
124 N(SEGREL32LSB), N(SEGREL64MSB), N(SEGREL64LSB), N(SECREL32MSB),
125 N(SECREL32LSB), N(SECREL64MSB), N(SECREL64LSB), N(REL32MSB),
126 N(REL32LSB), N(REL64MSB), N(REL64LSB), N(LTV32MSB),
127 N(LTV32LSB), N(LTV64MSB), N(LTV64LSB), N(PCREL21BI),
128 N(PCREL22), N(PCREL64I), N(IPLTMSB), N(IPLTLSB),
129 N(COPY), N(LTOFF22X), N(LDXMOV), N(TPREL14),
130 N(TPREL22), N(TPREL64I), N(TPREL64MSB), N(TPREL64LSB),
131 N(LTOFF_TPREL22), N(DTPMOD64MSB), N(DTPMOD64LSB), N(LTOFF_DTPMOD22),
132 N(DTPREL14), N(DTPREL22), N(DTPREL64I), N(DTPREL32MSB),
133 N(DTPREL32LSB), N(DTPREL64MSB), N(DTPREL64LSB), N(LTOFF_DTPREL22)
134 };
135
136 #undef N
137
138 /* Opaque struct for insns, to protect against derefs. */
139 struct insn;
140
141 static inline uint64_t
142 bundle (const struct insn *insn)
143 {
144 return (uint64_t) insn & ~0xfUL;
145 }
146
147 static inline int
148 slot (const struct insn *insn)
149 {
150 return (uint64_t) insn & 0x3;
151 }
152
153 static int
154 apply_imm64 (struct module *mod, struct insn *insn, uint64_t val)
155 {
156 if (slot(insn) != 2) {
157 printk(KERN_ERR "%s: invalid slot number %d for IMM64\n",
158 mod->name, slot(insn));
159 return 0;
160 }
161 ia64_patch_imm64((u64) insn, val);
162 return 1;
163 }
164
165 static int
166 apply_imm60 (struct module *mod, struct insn *insn, uint64_t val)
167 {
168 if (slot(insn) != 2) {
169 printk(KERN_ERR "%s: invalid slot number %d for IMM60\n",
170 mod->name, slot(insn));
171 return 0;
172 }
173 if (val + ((uint64_t) 1 << 59) >= (1UL << 60)) {
174 printk(KERN_ERR "%s: value %ld out of IMM60 range\n", mod->name, (int64_t) val);
175 return 0;
176 }
177 ia64_patch_imm60((u64) insn, val);
178 return 1;
179 }
180
181 static int
182 apply_imm22 (struct module *mod, struct insn *insn, uint64_t val)
183 {
184 if (val + (1 << 21) >= (1 << 22)) {
185 printk(KERN_ERR "%s: value %li out of IMM22 range\n", mod->name, (int64_t)val);
186 return 0;
187 }
188 ia64_patch((u64) insn, 0x01fffcfe000UL, ( ((val & 0x200000UL) << 15) /* bit 21 -> 36 */
189 | ((val & 0x1f0000UL) << 6) /* bit 16 -> 22 */
190 | ((val & 0x00ff80UL) << 20) /* bit 7 -> 27 */
191 | ((val & 0x00007fUL) << 13) /* bit 0 -> 13 */));
192 return 1;
193 }
194
195 static int
196 apply_imm21b (struct module *mod, struct insn *insn, uint64_t val)
197 {
198 if (val + (1 << 20) >= (1 << 21)) {
199 printk(KERN_ERR "%s: value %li out of IMM21b range\n", mod->name, (int64_t)val);
200 return 0;
201 }
202 ia64_patch((u64) insn, 0x11ffffe000UL, ( ((val & 0x100000UL) << 16) /* bit 20 -> 36 */
203 | ((val & 0x0fffffUL) << 13) /* bit 0 -> 13 */));
204 return 1;
205 }
206
207 #if USE_BRL
208
209 struct plt_entry {
210 /* Three instruction bundles in PLT. */
211 unsigned char bundle[2][16];
212 };
213
214 static const struct plt_entry ia64_plt_template = {
215 {
216 {
217 0x04, 0x00, 0x00, 0x00, 0x01, 0x00, /* [MLX] nop.m 0 */
218 0x00, 0x00, 0x00, 0x00, 0x00, 0x20, /* movl gp=TARGET_GP */
219 0x00, 0x00, 0x00, 0x60
220 },
221 {
222 0x05, 0x00, 0x00, 0x00, 0x01, 0x00, /* [MLX] nop.m 0 */
223 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, /* brl.many gp=TARGET_GP */
224 0x08, 0x00, 0x00, 0xc0
225 }
226 }
227 };
228
229 static int
230 patch_plt (struct module *mod, struct plt_entry *plt, long target_ip, unsigned long target_gp)
231 {
232 if (apply_imm64(mod, (struct insn *) (plt->bundle[0] + 2), target_gp)
233 && apply_imm60(mod, (struct insn *) (plt->bundle[1] + 2),
234 (target_ip - (int64_t) plt->bundle[1]) / 16))
235 return 1;
236 return 0;
237 }
238
239 unsigned long
240 plt_target (struct plt_entry *plt)
241 {
242 uint64_t b0, b1, *b = (uint64_t *) plt->bundle[1];
243 long off;
244
245 b0 = b[0]; b1 = b[1];
246 off = ( ((b1 & 0x00fffff000000000UL) >> 36) /* imm20b -> bit 0 */
247 | ((b0 >> 48) << 20) | ((b1 & 0x7fffffUL) << 36) /* imm39 -> bit 20 */
248 | ((b1 & 0x0800000000000000UL) << 0)); /* i -> bit 59 */
249 return (long) plt->bundle[1] + 16*off;
250 }
251
252 #else /* !USE_BRL */
253
254 struct plt_entry {
255 /* Three instruction bundles in PLT. */
256 unsigned char bundle[3][16];
257 };
258
259 static const struct plt_entry ia64_plt_template = {
260 {
261 {
262 0x05, 0x00, 0x00, 0x00, 0x01, 0x00, /* [MLX] nop.m 0 */
263 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, /* movl r16=TARGET_IP */
264 0x02, 0x00, 0x00, 0x60
265 },
266 {
267 0x04, 0x00, 0x00, 0x00, 0x01, 0x00, /* [MLX] nop.m 0 */
268 0x00, 0x00, 0x00, 0x00, 0x00, 0x20, /* movl gp=TARGET_GP */
269 0x00, 0x00, 0x00, 0x60
270 },
271 {
272 0x11, 0x00, 0x00, 0x00, 0x01, 0x00, /* [MIB] nop.m 0 */
273 0x60, 0x80, 0x04, 0x80, 0x03, 0x00, /* mov b6=r16 */
274 0x60, 0x00, 0x80, 0x00 /* br.few b6 */
275 }
276 }
277 };
278
279 static int
280 patch_plt (struct module *mod, struct plt_entry *plt, long target_ip, unsigned long target_gp)
281 {
282 if (apply_imm64(mod, (struct insn *) (plt->bundle[0] + 2), target_ip)
283 && apply_imm64(mod, (struct insn *) (plt->bundle[1] + 2), target_gp))
284 return 1;
285 return 0;
286 }
287
288 unsigned long
289 plt_target (struct plt_entry *plt)
290 {
291 uint64_t b0, b1, *b = (uint64_t *) plt->bundle[0];
292
293 b0 = b[0]; b1 = b[1];
294 return ( ((b1 & 0x000007f000000000) >> 36) /* imm7b -> bit 0 */
295 | ((b1 & 0x07fc000000000000) >> 43) /* imm9d -> bit 7 */
296 | ((b1 & 0x0003e00000000000) >> 29) /* imm5c -> bit 16 */
297 | ((b1 & 0x0000100000000000) >> 23) /* ic -> bit 21 */
298 | ((b0 >> 46) << 22) | ((b1 & 0x7fffff) << 40) /* imm41 -> bit 22 */
299 | ((b1 & 0x0800000000000000) << 4)); /* i -> bit 63 */
300 }
301
302 #endif /* !USE_BRL */
303
304 void *
305 module_alloc (unsigned long size)
306 {
307 if (!size)
308 return NULL;
309 return vmalloc(size);
310 }
311
312 void
313 module_free (struct module *mod, void *module_region)
314 {
315 if (mod && mod->arch.init_unw_table &&
316 module_region == mod->module_init) {
317 unw_remove_unwind_table(mod->arch.init_unw_table);
318 mod->arch.init_unw_table = NULL;
319 }
320 vfree(module_region);
321 }
322
323 /* Have we already seen one of these relocations? */
324 /* FIXME: we could look in other sections, too --RR */
325 static int
326 duplicate_reloc (const Elf64_Rela *rela, unsigned int num)
327 {
328 unsigned int i;
329
330 for (i = 0; i < num; i++) {
331 if (rela[i].r_info == rela[num].r_info && rela[i].r_addend == rela[num].r_addend)
332 return 1;
333 }
334 return 0;
335 }
336
337 /* Count how many GOT entries we may need */
338 static unsigned int
339 count_gots (const Elf64_Rela *rela, unsigned int num)
340 {
341 unsigned int i, ret = 0;
342
343 /* Sure, this is order(n^2), but it's usually short, and not
344 time critical */
345 for (i = 0; i < num; i++) {
346 switch (ELF64_R_TYPE(rela[i].r_info)) {
347 case R_IA64_LTOFF22:
348 case R_IA64_LTOFF22X:
349 case R_IA64_LTOFF64I:
350 case R_IA64_LTOFF_FPTR22:
351 case R_IA64_LTOFF_FPTR64I:
352 case R_IA64_LTOFF_FPTR32MSB:
353 case R_IA64_LTOFF_FPTR32LSB:
354 case R_IA64_LTOFF_FPTR64MSB:
355 case R_IA64_LTOFF_FPTR64LSB:
356 if (!duplicate_reloc(rela, i))
357 ret++;
358 break;
359 }
360 }
361 return ret;
362 }
363
364 /* Count how many PLT entries we may need */
365 static unsigned int
366 count_plts (const Elf64_Rela *rela, unsigned int num)
367 {
368 unsigned int i, ret = 0;
369
370 /* Sure, this is order(n^2), but it's usually short, and not
371 time critical */
372 for (i = 0; i < num; i++) {
373 switch (ELF64_R_TYPE(rela[i].r_info)) {
374 case R_IA64_PCREL21B:
375 case R_IA64_PLTOFF22:
376 case R_IA64_PLTOFF64I:
377 case R_IA64_PLTOFF64MSB:
378 case R_IA64_PLTOFF64LSB:
379 case R_IA64_IPLTMSB:
380 case R_IA64_IPLTLSB:
381 if (!duplicate_reloc(rela, i))
382 ret++;
383 break;
384 }
385 }
386 return ret;
387 }
388
389 /* We need to create an function-descriptors for any internal function
390 which is referenced. */
391 static unsigned int
392 count_fdescs (const Elf64_Rela *rela, unsigned int num)
393 {
394 unsigned int i, ret = 0;
395
396 /* Sure, this is order(n^2), but it's usually short, and not time critical. */
397 for (i = 0; i < num; i++) {
398 switch (ELF64_R_TYPE(rela[i].r_info)) {
399 case R_IA64_FPTR64I:
400 case R_IA64_FPTR32LSB:
401 case R_IA64_FPTR32MSB:
402 case R_IA64_FPTR64LSB:
403 case R_IA64_FPTR64MSB:
404 case R_IA64_LTOFF_FPTR22:
405 case R_IA64_LTOFF_FPTR32LSB:
406 case R_IA64_LTOFF_FPTR32MSB:
407 case R_IA64_LTOFF_FPTR64I:
408 case R_IA64_LTOFF_FPTR64LSB:
409 case R_IA64_LTOFF_FPTR64MSB:
410 case R_IA64_IPLTMSB:
411 case R_IA64_IPLTLSB:
412 /*
413 * Jumps to static functions sometimes go straight to their
414 * offset. Of course, that may not be possible if the jump is
415 * from init -> core or vice. versa, so we need to generate an
416 * FDESC (and PLT etc) for that.
417 */
418 case R_IA64_PCREL21B:
419 if (!duplicate_reloc(rela, i))
420 ret++;
421 break;
422 }
423 }
424 return ret;
425 }
426
427 int
428 module_frob_arch_sections (Elf_Ehdr *ehdr, Elf_Shdr *sechdrs, char *secstrings,
429 struct module *mod)
430 {
431 unsigned long core_plts = 0, init_plts = 0, gots = 0, fdescs = 0;
432 Elf64_Shdr *s, *sechdrs_end = sechdrs + ehdr->e_shnum;
433
434 /*
435 * To store the PLTs and function-descriptors, we expand the .text section for
436 * core module-code and the .init.text section for initialization code.
437 */
438 for (s = sechdrs; s < sechdrs_end; ++s)
439 if (strcmp(".core.plt", secstrings + s->sh_name) == 0)
440 mod->arch.core_plt = s;
441 else if (strcmp(".init.plt", secstrings + s->sh_name) == 0)
442 mod->arch.init_plt = s;
443 else if (strcmp(".got", secstrings + s->sh_name) == 0)
444 mod->arch.got = s;
445 else if (strcmp(".opd", secstrings + s->sh_name) == 0)
446 mod->arch.opd = s;
447 else if (strcmp(".IA_64.unwind", secstrings + s->sh_name) == 0)
448 mod->arch.unwind = s;
449 #ifdef CONFIG_PARAVIRT
450 else if (strcmp(".paravirt_bundles",
451 secstrings + s->sh_name) == 0)
452 mod->arch.paravirt_bundles = s;
453 else if (strcmp(".paravirt_insts",
454 secstrings + s->sh_name) == 0)
455 mod->arch.paravirt_insts = s;
456 #endif
457
458 if (!mod->arch.core_plt || !mod->arch.init_plt || !mod->arch.got || !mod->arch.opd) {
459 printk(KERN_ERR "%s: sections missing\n", mod->name);
460 return -ENOEXEC;
461 }
462
463 /* GOT and PLTs can occur in any relocated section... */
464 for (s = sechdrs + 1; s < sechdrs_end; ++s) {
465 const Elf64_Rela *rels = (void *)ehdr + s->sh_offset;
466 unsigned long numrels = s->sh_size/sizeof(Elf64_Rela);
467
468 if (s->sh_type != SHT_RELA)
469 continue;
470
471 gots += count_gots(rels, numrels);
472 fdescs += count_fdescs(rels, numrels);
473 if (strstr(secstrings + s->sh_name, ".init"))
474 init_plts += count_plts(rels, numrels);
475 else
476 core_plts += count_plts(rels, numrels);
477 }
478
479 mod->arch.core_plt->sh_type = SHT_NOBITS;
480 mod->arch.core_plt->sh_flags = SHF_EXECINSTR | SHF_ALLOC;
481 mod->arch.core_plt->sh_addralign = 16;
482 mod->arch.core_plt->sh_size = core_plts * sizeof(struct plt_entry);
483 mod->arch.init_plt->sh_type = SHT_NOBITS;
484 mod->arch.init_plt->sh_flags = SHF_EXECINSTR | SHF_ALLOC;
485 mod->arch.init_plt->sh_addralign = 16;
486 mod->arch.init_plt->sh_size = init_plts * sizeof(struct plt_entry);
487 mod->arch.got->sh_type = SHT_NOBITS;
488 mod->arch.got->sh_flags = ARCH_SHF_SMALL | SHF_ALLOC;
489 mod->arch.got->sh_addralign = 8;
490 mod->arch.got->sh_size = gots * sizeof(struct got_entry);
491 mod->arch.opd->sh_type = SHT_NOBITS;
492 mod->arch.opd->sh_flags = SHF_ALLOC;
493 mod->arch.opd->sh_addralign = 8;
494 mod->arch.opd->sh_size = fdescs * sizeof(struct fdesc);
495 DEBUGP("%s: core.plt=%lx, init.plt=%lx, got=%lx, fdesc=%lx\n",
496 __func__, mod->arch.core_plt->sh_size, mod->arch.init_plt->sh_size,
497 mod->arch.got->sh_size, mod->arch.opd->sh_size);
498 return 0;
499 }
500
501 static inline int
502 in_init (const struct module *mod, uint64_t addr)
503 {
504 return addr - (uint64_t) mod->module_init < mod->init_size;
505 }
506
507 static inline int
508 in_core (const struct module *mod, uint64_t addr)
509 {
510 return addr - (uint64_t) mod->module_core < mod->core_size;
511 }
512
513 static inline int
514 is_internal (const struct module *mod, uint64_t value)
515 {
516 return in_init(mod, value) || in_core(mod, value);
517 }
518
519 /*
520 * Get gp-relative offset for the linkage-table entry of VALUE.
521 */
522 static uint64_t
523 get_ltoff (struct module *mod, uint64_t value, int *okp)
524 {
525 struct got_entry *got, *e;
526
527 if (!*okp)
528 return 0;
529
530 got = (void *) mod->arch.got->sh_addr;
531 for (e = got; e < got + mod->arch.next_got_entry; ++e)
532 if (e->val == value)
533 goto found;
534
535 /* Not enough GOT entries? */
536 BUG_ON(e >= (struct got_entry *) (mod->arch.got->sh_addr + mod->arch.got->sh_size));
537
538 e->val = value;
539 ++mod->arch.next_got_entry;
540 found:
541 return (uint64_t) e - mod->arch.gp;
542 }
543
544 static inline int
545 gp_addressable (struct module *mod, uint64_t value)
546 {
547 return value - mod->arch.gp + MAX_LTOFF/2 < MAX_LTOFF;
548 }
549
550 /* Get PC-relative PLT entry for this value. Returns 0 on failure. */
551 static uint64_t
552 get_plt (struct module *mod, const struct insn *insn, uint64_t value, int *okp)
553 {
554 struct plt_entry *plt, *plt_end;
555 uint64_t target_ip, target_gp;
556
557 if (!*okp)
558 return 0;
559
560 if (in_init(mod, (uint64_t) insn)) {
561 plt = (void *) mod->arch.init_plt->sh_addr;
562 plt_end = (void *) plt + mod->arch.init_plt->sh_size;
563 } else {
564 plt = (void *) mod->arch.core_plt->sh_addr;
565 plt_end = (void *) plt + mod->arch.core_plt->sh_size;
566 }
567
568 /* "value" is a pointer to a function-descriptor; fetch the target ip/gp from it: */
569 target_ip = ((uint64_t *) value)[0];
570 target_gp = ((uint64_t *) value)[1];
571
572 /* Look for existing PLT entry. */
573 while (plt->bundle[0][0]) {
574 if (plt_target(plt) == target_ip)
575 goto found;
576 if (++plt >= plt_end)
577 BUG();
578 }
579 *plt = ia64_plt_template;
580 if (!patch_plt(mod, plt, target_ip, target_gp)) {
581 *okp = 0;
582 return 0;
583 }
584 #if ARCH_MODULE_DEBUG
585 if (plt_target(plt) != target_ip) {
586 printk("%s: mistargeted PLT: wanted %lx, got %lx\n",
587 __func__, target_ip, plt_target(plt));
588 *okp = 0;
589 return 0;
590 }
591 #endif
592 found:
593 return (uint64_t) plt;
594 }
595
596 /* Get function descriptor for VALUE. */
597 static uint64_t
598 get_fdesc (struct module *mod, uint64_t value, int *okp)
599 {
600 struct fdesc *fdesc = (void *) mod->arch.opd->sh_addr;
601
602 if (!*okp)
603 return 0;
604
605 if (!value) {
606 printk(KERN_ERR "%s: fdesc for zero requested!\n", mod->name);
607 return 0;
608 }
609
610 if (!is_internal(mod, value))
611 /*
612 * If it's not a module-local entry-point, "value" already points to a
613 * function-descriptor.
614 */
615 return value;
616
617 /* Look for existing function descriptor. */
618 while (fdesc->ip) {
619 if (fdesc->ip == value)
620 return (uint64_t)fdesc;
621 if ((uint64_t) ++fdesc >= mod->arch.opd->sh_addr + mod->arch.opd->sh_size)
622 BUG();
623 }
624
625 /* Create new one */
626 fdesc->ip = value;
627 fdesc->gp = mod->arch.gp;
628 return (uint64_t) fdesc;
629 }
630
631 static inline int
632 do_reloc (struct module *mod, uint8_t r_type, Elf64_Sym *sym, uint64_t addend,
633 Elf64_Shdr *sec, void *location)
634 {
635 enum reloc_target_format format = (r_type >> FORMAT_SHIFT) & FORMAT_MASK;
636 enum reloc_value_formula formula = (r_type >> VALUE_SHIFT) & VALUE_MASK;
637 uint64_t val;
638 int ok = 1;
639
640 val = sym->st_value + addend;
641
642 switch (formula) {
643 case RV_SEGREL: /* segment base is arbitrarily chosen to be 0 for kernel modules */
644 case RV_DIRECT:
645 break;
646
647 case RV_GPREL: val -= mod->arch.gp; break;
648 case RV_LTREL: val = get_ltoff(mod, val, &ok); break;
649 case RV_PLTREL: val = get_plt(mod, location, val, &ok); break;
650 case RV_FPTR: val = get_fdesc(mod, val, &ok); break;
651 case RV_SECREL: val -= sec->sh_addr; break;
652 case RV_LTREL_FPTR: val = get_ltoff(mod, get_fdesc(mod, val, &ok), &ok); break;
653
654 case RV_PCREL:
655 switch (r_type) {
656 case R_IA64_PCREL21B:
657 if ((in_init(mod, val) && in_core(mod, (uint64_t)location)) ||
658 (in_core(mod, val) && in_init(mod, (uint64_t)location))) {
659 /*
660 * Init section may have been allocated far away from core,
661 * if the branch won't reach, then allocate a plt for it.
662 */
663 uint64_t delta = ((int64_t)val - (int64_t)location) / 16;
664 if (delta + (1 << 20) >= (1 << 21)) {
665 val = get_fdesc(mod, val, &ok);
666 val = get_plt(mod, location, val, &ok);
667 }
668 } else if (!is_internal(mod, val))
669 val = get_plt(mod, location, val, &ok);
670 /* FALL THROUGH */
671 default:
672 val -= bundle(location);
673 break;
674
675 case R_IA64_PCREL32MSB:
676 case R_IA64_PCREL32LSB:
677 case R_IA64_PCREL64MSB:
678 case R_IA64_PCREL64LSB:
679 val -= (uint64_t) location;
680 break;
681
682 }
683 switch (r_type) {
684 case R_IA64_PCREL60B: format = RF_INSN60; break;
685 case R_IA64_PCREL21B: format = RF_INSN21B; break;
686 case R_IA64_PCREL21M: format = RF_INSN21M; break;
687 case R_IA64_PCREL21F: format = RF_INSN21F; break;
688 default: break;
689 }
690 break;
691
692 case RV_BDREL:
693 val -= (uint64_t) (in_init(mod, val) ? mod->module_init : mod->module_core);
694 break;
695
696 case RV_LTV:
697 /* can link-time value relocs happen here? */
698 BUG();
699 break;
700
701 case RV_PCREL2:
702 if (r_type == R_IA64_PCREL21BI) {
703 if (!is_internal(mod, val)) {
704 printk(KERN_ERR "%s: %s reloc against non-local symbol (%lx)\n",
705 __func__, reloc_name[r_type], val);
706 return -ENOEXEC;
707 }
708 format = RF_INSN21B;
709 }
710 val -= bundle(location);
711 break;
712
713 case RV_SPECIAL:
714 switch (r_type) {
715 case R_IA64_IPLTMSB:
716 case R_IA64_IPLTLSB:
717 val = get_fdesc(mod, get_plt(mod, location, val, &ok), &ok);
718 format = RF_64LSB;
719 if (r_type == R_IA64_IPLTMSB)
720 format = RF_64MSB;
721 break;
722
723 case R_IA64_SUB:
724 val = addend - sym->st_value;
725 format = RF_INSN64;
726 break;
727
728 case R_IA64_LTOFF22X:
729 if (gp_addressable(mod, val))
730 val -= mod->arch.gp;
731 else
732 val = get_ltoff(mod, val, &ok);
733 format = RF_INSN22;
734 break;
735
736 case R_IA64_LDXMOV:
737 if (gp_addressable(mod, val)) {
738 /* turn "ld8" into "mov": */
739 DEBUGP("%s: patching ld8 at %p to mov\n", __func__, location);
740 ia64_patch((u64) location, 0x1fff80fe000UL, 0x10000000000UL);
741 }
742 return 0;
743
744 default:
745 if (reloc_name[r_type])
746 printk(KERN_ERR "%s: special reloc %s not supported",
747 mod->name, reloc_name[r_type]);
748 else
749 printk(KERN_ERR "%s: unknown special reloc %x\n",
750 mod->name, r_type);
751 return -ENOEXEC;
752 }
753 break;
754
755 case RV_TPREL:
756 case RV_LTREL_TPREL:
757 case RV_DTPMOD:
758 case RV_LTREL_DTPMOD:
759 case RV_DTPREL:
760 case RV_LTREL_DTPREL:
761 printk(KERN_ERR "%s: %s reloc not supported\n",
762 mod->name, reloc_name[r_type] ? reloc_name[r_type] : "?");
763 return -ENOEXEC;
764
765 default:
766 printk(KERN_ERR "%s: unknown reloc %x\n", mod->name, r_type);
767 return -ENOEXEC;
768 }
769
770 if (!ok)
771 return -ENOEXEC;
772
773 DEBUGP("%s: [%p]<-%016lx = %s(%lx)\n", __func__, location, val,
774 reloc_name[r_type] ? reloc_name[r_type] : "?", sym->st_value + addend);
775
776 switch (format) {
777 case RF_INSN21B: ok = apply_imm21b(mod, location, (int64_t) val / 16); break;
778 case RF_INSN22: ok = apply_imm22(mod, location, val); break;
779 case RF_INSN64: ok = apply_imm64(mod, location, val); break;
780 case RF_INSN60: ok = apply_imm60(mod, location, (int64_t) val / 16); break;
781 case RF_32LSB: put_unaligned(val, (uint32_t *) location); break;
782 case RF_64LSB: put_unaligned(val, (uint64_t *) location); break;
783 case RF_32MSB: /* ia64 Linux is little-endian... */
784 case RF_64MSB: /* ia64 Linux is little-endian... */
785 case RF_INSN14: /* must be within-module, i.e., resolved by "ld -r" */
786 case RF_INSN21M: /* must be within-module, i.e., resolved by "ld -r" */
787 case RF_INSN21F: /* must be within-module, i.e., resolved by "ld -r" */
788 printk(KERN_ERR "%s: format %u needed by %s reloc is not supported\n",
789 mod->name, format, reloc_name[r_type] ? reloc_name[r_type] : "?");
790 return -ENOEXEC;
791
792 default:
793 printk(KERN_ERR "%s: relocation %s resulted in unknown format %u\n",
794 mod->name, reloc_name[r_type] ? reloc_name[r_type] : "?", format);
795 return -ENOEXEC;
796 }
797 return ok ? 0 : -ENOEXEC;
798 }
799
800 int
801 apply_relocate_add (Elf64_Shdr *sechdrs, const char *strtab, unsigned int symindex,
802 unsigned int relsec, struct module *mod)
803 {
804 unsigned int i, n = sechdrs[relsec].sh_size / sizeof(Elf64_Rela);
805 Elf64_Rela *rela = (void *) sechdrs[relsec].sh_addr;
806 Elf64_Shdr *target_sec;
807 int ret;
808
809 DEBUGP("%s: applying section %u (%u relocs) to %u\n", __func__,
810 relsec, n, sechdrs[relsec].sh_info);
811
812 target_sec = sechdrs + sechdrs[relsec].sh_info;
813
814 if (target_sec->sh_entsize == ~0UL)
815 /*
816 * If target section wasn't allocated, we don't need to relocate it.
817 * Happens, e.g., for debug sections.
818 */
819 return 0;
820
821 if (!mod->arch.gp) {
822 /*
823 * XXX Should have an arch-hook for running this after final section
824 * addresses have been selected...
825 */
826 uint64_t gp;
827 if (mod->core_size > MAX_LTOFF)
828 /*
829 * This takes advantage of fact that SHF_ARCH_SMALL gets allocated
830 * at the end of the module.
831 */
832 gp = mod->core_size - MAX_LTOFF / 2;
833 else
834 gp = mod->core_size / 2;
835 gp = (uint64_t) mod->module_core + ((gp + 7) & -8);
836 mod->arch.gp = gp;
837 DEBUGP("%s: placing gp at 0x%lx\n", __func__, gp);
838 }
839
840 for (i = 0; i < n; i++) {
841 ret = do_reloc(mod, ELF64_R_TYPE(rela[i].r_info),
842 ((Elf64_Sym *) sechdrs[symindex].sh_addr
843 + ELF64_R_SYM(rela[i].r_info)),
844 rela[i].r_addend, target_sec,
845 (void *) target_sec->sh_addr + rela[i].r_offset);
846 if (ret < 0)
847 return ret;
848 }
849 return 0;
850 }
851
852 int
853 apply_relocate (Elf64_Shdr *sechdrs, const char *strtab, unsigned int symindex,
854 unsigned int relsec, struct module *mod)
855 {
856 printk(KERN_ERR "module %s: REL relocs in section %u unsupported\n", mod->name, relsec);
857 return -ENOEXEC;
858 }
859
860 /*
861 * Modules contain a single unwind table which covers both the core and the init text
862 * sections but since the two are not contiguous, we need to split this table up such that
863 * we can register (and unregister) each "segment" separately. Fortunately, this sounds
864 * more complicated than it really is.
865 */
866 static void
867 register_unwind_table (struct module *mod)
868 {
869 struct unw_table_entry *start = (void *) mod->arch.unwind->sh_addr;
870 struct unw_table_entry *end = start + mod->arch.unwind->sh_size / sizeof (*start);
871 struct unw_table_entry tmp, *e1, *e2, *core, *init;
872 unsigned long num_init = 0, num_core = 0;
873
874 /* First, count how many init and core unwind-table entries there are. */
875 for (e1 = start; e1 < end; ++e1)
876 if (in_init(mod, e1->start_offset))
877 ++num_init;
878 else
879 ++num_core;
880 /*
881 * Second, sort the table such that all unwind-table entries for the init and core
882 * text sections are nicely separated. We do this with a stupid bubble sort
883 * (unwind tables don't get ridiculously huge).
884 */
885 for (e1 = start; e1 < end; ++e1) {
886 for (e2 = e1 + 1; e2 < end; ++e2) {
887 if (e2->start_offset < e1->start_offset) {
888 tmp = *e1;
889 *e1 = *e2;
890 *e2 = tmp;
891 }
892 }
893 }
894 /*
895 * Third, locate the init and core segments in the unwind table:
896 */
897 if (in_init(mod, start->start_offset)) {
898 init = start;
899 core = start + num_init;
900 } else {
901 core = start;
902 init = start + num_core;
903 }
904
905 DEBUGP("%s: name=%s, gp=%lx, num_init=%lu, num_core=%lu\n", __func__,
906 mod->name, mod->arch.gp, num_init, num_core);
907
908 /*
909 * Fourth, register both tables (if not empty).
910 */
911 if (num_core > 0) {
912 mod->arch.core_unw_table = unw_add_unwind_table(mod->name, 0, mod->arch.gp,
913 core, core + num_core);
914 DEBUGP("%s: core: handle=%p [%p-%p)\n", __func__,
915 mod->arch.core_unw_table, core, core + num_core);
916 }
917 if (num_init > 0) {
918 mod->arch.init_unw_table = unw_add_unwind_table(mod->name, 0, mod->arch.gp,
919 init, init + num_init);
920 DEBUGP("%s: init: handle=%p [%p-%p)\n", __func__,
921 mod->arch.init_unw_table, init, init + num_init);
922 }
923 }
924
925 int
926 module_finalize (const Elf_Ehdr *hdr, const Elf_Shdr *sechdrs, struct module *mod)
927 {
928 DEBUGP("%s: init: entry=%p\n", __func__, mod->init);
929 if (mod->arch.unwind)
930 register_unwind_table(mod);
931 #ifdef CONFIG_PARAVIRT
932 if (mod->arch.paravirt_bundles) {
933 struct paravirt_patch_site_bundle *start =
934 (struct paravirt_patch_site_bundle *)
935 mod->arch.paravirt_bundles->sh_addr;
936 struct paravirt_patch_site_bundle *end =
937 (struct paravirt_patch_site_bundle *)
938 (mod->arch.paravirt_bundles->sh_addr +
939 mod->arch.paravirt_bundles->sh_size);
940
941 paravirt_patch_apply_bundle(start, end);
942 }
943 if (mod->arch.paravirt_insts) {
944 struct paravirt_patch_site_inst *start =
945 (struct paravirt_patch_site_inst *)
946 mod->arch.paravirt_insts->sh_addr;
947 struct paravirt_patch_site_inst *end =
948 (struct paravirt_patch_site_inst *)
949 (mod->arch.paravirt_insts->sh_addr +
950 mod->arch.paravirt_insts->sh_size);
951
952 paravirt_patch_apply_inst(start, end);
953 }
954 #endif
955 return 0;
956 }
957
958 void
959 module_arch_cleanup (struct module *mod)
960 {
961 if (mod->arch.init_unw_table)
962 unw_remove_unwind_table(mod->arch.init_unw_table);
963 if (mod->arch.core_unw_table)
964 unw_remove_unwind_table(mod->arch.core_unw_table);
965 }
Linux kernel - Deliverables
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