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1da177e4 LT |
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 | ||
1da177e4 LT |
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 | ||
1da177e4 LT |
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)) { | |
e088a4ad MW |
174 | printk(KERN_ERR "%s: value %ld out of IMM60 range\n", |
175 | mod->name, (long) val); | |
1da177e4 LT |
176 | return 0; |
177 | } | |
178 | ia64_patch_imm60((u64) insn, val); | |
179 | return 1; | |
180 | } | |
181 | ||
182 | static int | |
183 | apply_imm22 (struct module *mod, struct insn *insn, uint64_t val) | |
184 | { | |
185 | if (val + (1 << 21) >= (1 << 22)) { | |
e088a4ad MW |
186 | printk(KERN_ERR "%s: value %li out of IMM22 range\n", |
187 | mod->name, (long)val); | |
1da177e4 LT |
188 | return 0; |
189 | } | |
190 | ia64_patch((u64) insn, 0x01fffcfe000UL, ( ((val & 0x200000UL) << 15) /* bit 21 -> 36 */ | |
191 | | ((val & 0x1f0000UL) << 6) /* bit 16 -> 22 */ | |
192 | | ((val & 0x00ff80UL) << 20) /* bit 7 -> 27 */ | |
193 | | ((val & 0x00007fUL) << 13) /* bit 0 -> 13 */)); | |
194 | return 1; | |
195 | } | |
196 | ||
197 | static int | |
198 | apply_imm21b (struct module *mod, struct insn *insn, uint64_t val) | |
199 | { | |
200 | if (val + (1 << 20) >= (1 << 21)) { | |
e088a4ad MW |
201 | printk(KERN_ERR "%s: value %li out of IMM21b range\n", |
202 | mod->name, (long)val); | |
1da177e4 LT |
203 | return 0; |
204 | } | |
205 | ia64_patch((u64) insn, 0x11ffffe000UL, ( ((val & 0x100000UL) << 16) /* bit 20 -> 36 */ | |
206 | | ((val & 0x0fffffUL) << 13) /* bit 0 -> 13 */)); | |
207 | return 1; | |
208 | } | |
209 | ||
210 | #if USE_BRL | |
211 | ||
212 | struct plt_entry { | |
213 | /* Three instruction bundles in PLT. */ | |
214 | unsigned char bundle[2][16]; | |
215 | }; | |
216 | ||
217 | static const struct plt_entry ia64_plt_template = { | |
218 | { | |
219 | { | |
220 | 0x04, 0x00, 0x00, 0x00, 0x01, 0x00, /* [MLX] nop.m 0 */ | |
221 | 0x00, 0x00, 0x00, 0x00, 0x00, 0x20, /* movl gp=TARGET_GP */ | |
222 | 0x00, 0x00, 0x00, 0x60 | |
223 | }, | |
224 | { | |
225 | 0x05, 0x00, 0x00, 0x00, 0x01, 0x00, /* [MLX] nop.m 0 */ | |
226 | 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, /* brl.many gp=TARGET_GP */ | |
227 | 0x08, 0x00, 0x00, 0xc0 | |
228 | } | |
229 | } | |
230 | }; | |
231 | ||
232 | static int | |
233 | patch_plt (struct module *mod, struct plt_entry *plt, long target_ip, unsigned long target_gp) | |
234 | { | |
235 | if (apply_imm64(mod, (struct insn *) (plt->bundle[0] + 2), target_gp) | |
236 | && apply_imm60(mod, (struct insn *) (plt->bundle[1] + 2), | |
237 | (target_ip - (int64_t) plt->bundle[1]) / 16)) | |
238 | return 1; | |
239 | return 0; | |
240 | } | |
241 | ||
242 | unsigned long | |
243 | plt_target (struct plt_entry *plt) | |
244 | { | |
245 | uint64_t b0, b1, *b = (uint64_t *) plt->bundle[1]; | |
246 | long off; | |
247 | ||
248 | b0 = b[0]; b1 = b[1]; | |
249 | off = ( ((b1 & 0x00fffff000000000UL) >> 36) /* imm20b -> bit 0 */ | |
250 | | ((b0 >> 48) << 20) | ((b1 & 0x7fffffUL) << 36) /* imm39 -> bit 20 */ | |
251 | | ((b1 & 0x0800000000000000UL) << 0)); /* i -> bit 59 */ | |
252 | return (long) plt->bundle[1] + 16*off; | |
253 | } | |
254 | ||
255 | #else /* !USE_BRL */ | |
256 | ||
257 | struct plt_entry { | |
258 | /* Three instruction bundles in PLT. */ | |
259 | unsigned char bundle[3][16]; | |
260 | }; | |
261 | ||
262 | static const struct plt_entry ia64_plt_template = { | |
263 | { | |
264 | { | |
265 | 0x05, 0x00, 0x00, 0x00, 0x01, 0x00, /* [MLX] nop.m 0 */ | |
266 | 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, /* movl r16=TARGET_IP */ | |
267 | 0x02, 0x00, 0x00, 0x60 | |
268 | }, | |
269 | { | |
270 | 0x04, 0x00, 0x00, 0x00, 0x01, 0x00, /* [MLX] nop.m 0 */ | |
271 | 0x00, 0x00, 0x00, 0x00, 0x00, 0x20, /* movl gp=TARGET_GP */ | |
272 | 0x00, 0x00, 0x00, 0x60 | |
273 | }, | |
274 | { | |
275 | 0x11, 0x00, 0x00, 0x00, 0x01, 0x00, /* [MIB] nop.m 0 */ | |
276 | 0x60, 0x80, 0x04, 0x80, 0x03, 0x00, /* mov b6=r16 */ | |
277 | 0x60, 0x00, 0x80, 0x00 /* br.few b6 */ | |
278 | } | |
279 | } | |
280 | }; | |
281 | ||
282 | static int | |
283 | patch_plt (struct module *mod, struct plt_entry *plt, long target_ip, unsigned long target_gp) | |
284 | { | |
285 | if (apply_imm64(mod, (struct insn *) (plt->bundle[0] + 2), target_ip) | |
286 | && apply_imm64(mod, (struct insn *) (plt->bundle[1] + 2), target_gp)) | |
287 | return 1; | |
288 | return 0; | |
289 | } | |
290 | ||
291 | unsigned long | |
292 | plt_target (struct plt_entry *plt) | |
293 | { | |
294 | uint64_t b0, b1, *b = (uint64_t *) plt->bundle[0]; | |
295 | ||
296 | b0 = b[0]; b1 = b[1]; | |
297 | return ( ((b1 & 0x000007f000000000) >> 36) /* imm7b -> bit 0 */ | |
298 | | ((b1 & 0x07fc000000000000) >> 43) /* imm9d -> bit 7 */ | |
299 | | ((b1 & 0x0003e00000000000) >> 29) /* imm5c -> bit 16 */ | |
300 | | ((b1 & 0x0000100000000000) >> 23) /* ic -> bit 21 */ | |
301 | | ((b0 >> 46) << 22) | ((b1 & 0x7fffff) << 40) /* imm41 -> bit 22 */ | |
302 | | ((b1 & 0x0800000000000000) << 4)); /* i -> bit 63 */ | |
303 | } | |
304 | ||
305 | #endif /* !USE_BRL */ | |
306 | ||
307 | void * | |
308 | module_alloc (unsigned long size) | |
309 | { | |
310 | if (!size) | |
311 | return NULL; | |
312 | return vmalloc(size); | |
313 | } | |
314 | ||
315 | void | |
316 | module_free (struct module *mod, void *module_region) | |
317 | { | |
740a8de0 AN |
318 | if (mod && mod->arch.init_unw_table && |
319 | module_region == mod->module_init) { | |
1da177e4 LT |
320 | unw_remove_unwind_table(mod->arch.init_unw_table); |
321 | mod->arch.init_unw_table = NULL; | |
322 | } | |
323 | vfree(module_region); | |
324 | } | |
325 | ||
326 | /* Have we already seen one of these relocations? */ | |
327 | /* FIXME: we could look in other sections, too --RR */ | |
328 | static int | |
329 | duplicate_reloc (const Elf64_Rela *rela, unsigned int num) | |
330 | { | |
331 | unsigned int i; | |
332 | ||
333 | for (i = 0; i < num; i++) { | |
334 | if (rela[i].r_info == rela[num].r_info && rela[i].r_addend == rela[num].r_addend) | |
335 | return 1; | |
336 | } | |
337 | return 0; | |
338 | } | |
339 | ||
340 | /* Count how many GOT entries we may need */ | |
341 | static unsigned int | |
342 | count_gots (const Elf64_Rela *rela, unsigned int num) | |
343 | { | |
344 | unsigned int i, ret = 0; | |
345 | ||
346 | /* Sure, this is order(n^2), but it's usually short, and not | |
347 | time critical */ | |
348 | for (i = 0; i < num; i++) { | |
349 | switch (ELF64_R_TYPE(rela[i].r_info)) { | |
350 | case R_IA64_LTOFF22: | |
351 | case R_IA64_LTOFF22X: | |
352 | case R_IA64_LTOFF64I: | |
353 | case R_IA64_LTOFF_FPTR22: | |
354 | case R_IA64_LTOFF_FPTR64I: | |
355 | case R_IA64_LTOFF_FPTR32MSB: | |
356 | case R_IA64_LTOFF_FPTR32LSB: | |
357 | case R_IA64_LTOFF_FPTR64MSB: | |
358 | case R_IA64_LTOFF_FPTR64LSB: | |
359 | if (!duplicate_reloc(rela, i)) | |
360 | ret++; | |
361 | break; | |
362 | } | |
363 | } | |
364 | return ret; | |
365 | } | |
366 | ||
367 | /* Count how many PLT entries we may need */ | |
368 | static unsigned int | |
369 | count_plts (const Elf64_Rela *rela, unsigned int num) | |
370 | { | |
371 | unsigned int i, ret = 0; | |
372 | ||
373 | /* Sure, this is order(n^2), but it's usually short, and not | |
374 | time critical */ | |
375 | for (i = 0; i < num; i++) { | |
376 | switch (ELF64_R_TYPE(rela[i].r_info)) { | |
377 | case R_IA64_PCREL21B: | |
378 | case R_IA64_PLTOFF22: | |
379 | case R_IA64_PLTOFF64I: | |
380 | case R_IA64_PLTOFF64MSB: | |
381 | case R_IA64_PLTOFF64LSB: | |
382 | case R_IA64_IPLTMSB: | |
383 | case R_IA64_IPLTLSB: | |
384 | if (!duplicate_reloc(rela, i)) | |
385 | ret++; | |
386 | break; | |
387 | } | |
388 | } | |
389 | return ret; | |
390 | } | |
391 | ||
392 | /* We need to create an function-descriptors for any internal function | |
393 | which is referenced. */ | |
394 | static unsigned int | |
395 | count_fdescs (const Elf64_Rela *rela, unsigned int num) | |
396 | { | |
397 | unsigned int i, ret = 0; | |
398 | ||
399 | /* Sure, this is order(n^2), but it's usually short, and not time critical. */ | |
400 | for (i = 0; i < num; i++) { | |
401 | switch (ELF64_R_TYPE(rela[i].r_info)) { | |
402 | case R_IA64_FPTR64I: | |
403 | case R_IA64_FPTR32LSB: | |
404 | case R_IA64_FPTR32MSB: | |
405 | case R_IA64_FPTR64LSB: | |
406 | case R_IA64_FPTR64MSB: | |
407 | case R_IA64_LTOFF_FPTR22: | |
408 | case R_IA64_LTOFF_FPTR32LSB: | |
409 | case R_IA64_LTOFF_FPTR32MSB: | |
410 | case R_IA64_LTOFF_FPTR64I: | |
411 | case R_IA64_LTOFF_FPTR64LSB: | |
412 | case R_IA64_LTOFF_FPTR64MSB: | |
413 | case R_IA64_IPLTMSB: | |
414 | case R_IA64_IPLTLSB: | |
415 | /* | |
416 | * Jumps to static functions sometimes go straight to their | |
417 | * offset. Of course, that may not be possible if the jump is | |
418 | * from init -> core or vice. versa, so we need to generate an | |
419 | * FDESC (and PLT etc) for that. | |
420 | */ | |
421 | case R_IA64_PCREL21B: | |
422 | if (!duplicate_reloc(rela, i)) | |
423 | ret++; | |
424 | break; | |
425 | } | |
426 | } | |
427 | return ret; | |
428 | } | |
429 | ||
430 | int | |
431 | module_frob_arch_sections (Elf_Ehdr *ehdr, Elf_Shdr *sechdrs, char *secstrings, | |
432 | struct module *mod) | |
433 | { | |
434 | unsigned long core_plts = 0, init_plts = 0, gots = 0, fdescs = 0; | |
435 | Elf64_Shdr *s, *sechdrs_end = sechdrs + ehdr->e_shnum; | |
436 | ||
437 | /* | |
438 | * To store the PLTs and function-descriptors, we expand the .text section for | |
439 | * core module-code and the .init.text section for initialization code. | |
440 | */ | |
441 | for (s = sechdrs; s < sechdrs_end; ++s) | |
442 | if (strcmp(".core.plt", secstrings + s->sh_name) == 0) | |
443 | mod->arch.core_plt = s; | |
444 | else if (strcmp(".init.plt", secstrings + s->sh_name) == 0) | |
445 | mod->arch.init_plt = s; | |
446 | else if (strcmp(".got", secstrings + s->sh_name) == 0) | |
447 | mod->arch.got = s; | |
448 | else if (strcmp(".opd", secstrings + s->sh_name) == 0) | |
449 | mod->arch.opd = s; | |
450 | else if (strcmp(".IA_64.unwind", secstrings + s->sh_name) == 0) | |
451 | mod->arch.unwind = s; | |
ee158fcd IY |
452 | #ifdef CONFIG_PARAVIRT |
453 | else if (strcmp(".paravirt_bundles", | |
454 | secstrings + s->sh_name) == 0) | |
455 | mod->arch.paravirt_bundles = s; | |
456 | else if (strcmp(".paravirt_insts", | |
457 | secstrings + s->sh_name) == 0) | |
458 | mod->arch.paravirt_insts = s; | |
459 | #endif | |
1da177e4 LT |
460 | |
461 | if (!mod->arch.core_plt || !mod->arch.init_plt || !mod->arch.got || !mod->arch.opd) { | |
462 | printk(KERN_ERR "%s: sections missing\n", mod->name); | |
463 | return -ENOEXEC; | |
464 | } | |
465 | ||
466 | /* GOT and PLTs can occur in any relocated section... */ | |
467 | for (s = sechdrs + 1; s < sechdrs_end; ++s) { | |
468 | const Elf64_Rela *rels = (void *)ehdr + s->sh_offset; | |
469 | unsigned long numrels = s->sh_size/sizeof(Elf64_Rela); | |
470 | ||
471 | if (s->sh_type != SHT_RELA) | |
472 | continue; | |
473 | ||
474 | gots += count_gots(rels, numrels); | |
475 | fdescs += count_fdescs(rels, numrels); | |
476 | if (strstr(secstrings + s->sh_name, ".init")) | |
477 | init_plts += count_plts(rels, numrels); | |
478 | else | |
479 | core_plts += count_plts(rels, numrels); | |
480 | } | |
481 | ||
482 | mod->arch.core_plt->sh_type = SHT_NOBITS; | |
483 | mod->arch.core_plt->sh_flags = SHF_EXECINSTR | SHF_ALLOC; | |
484 | mod->arch.core_plt->sh_addralign = 16; | |
485 | mod->arch.core_plt->sh_size = core_plts * sizeof(struct plt_entry); | |
486 | mod->arch.init_plt->sh_type = SHT_NOBITS; | |
487 | mod->arch.init_plt->sh_flags = SHF_EXECINSTR | SHF_ALLOC; | |
488 | mod->arch.init_plt->sh_addralign = 16; | |
489 | mod->arch.init_plt->sh_size = init_plts * sizeof(struct plt_entry); | |
490 | mod->arch.got->sh_type = SHT_NOBITS; | |
491 | mod->arch.got->sh_flags = ARCH_SHF_SMALL | SHF_ALLOC; | |
492 | mod->arch.got->sh_addralign = 8; | |
493 | mod->arch.got->sh_size = gots * sizeof(struct got_entry); | |
494 | mod->arch.opd->sh_type = SHT_NOBITS; | |
495 | mod->arch.opd->sh_flags = SHF_ALLOC; | |
496 | mod->arch.opd->sh_addralign = 8; | |
497 | mod->arch.opd->sh_size = fdescs * sizeof(struct fdesc); | |
498 | DEBUGP("%s: core.plt=%lx, init.plt=%lx, got=%lx, fdesc=%lx\n", | |
d4ed8084 | 499 | __func__, mod->arch.core_plt->sh_size, mod->arch.init_plt->sh_size, |
1da177e4 LT |
500 | mod->arch.got->sh_size, mod->arch.opd->sh_size); |
501 | return 0; | |
502 | } | |
503 | ||
504 | static inline int | |
505 | in_init (const struct module *mod, uint64_t addr) | |
506 | { | |
507 | return addr - (uint64_t) mod->module_init < mod->init_size; | |
508 | } | |
509 | ||
510 | static inline int | |
511 | in_core (const struct module *mod, uint64_t addr) | |
512 | { | |
513 | return addr - (uint64_t) mod->module_core < mod->core_size; | |
514 | } | |
515 | ||
516 | static inline int | |
517 | is_internal (const struct module *mod, uint64_t value) | |
518 | { | |
519 | return in_init(mod, value) || in_core(mod, value); | |
520 | } | |
521 | ||
522 | /* | |
523 | * Get gp-relative offset for the linkage-table entry of VALUE. | |
524 | */ | |
525 | static uint64_t | |
526 | get_ltoff (struct module *mod, uint64_t value, int *okp) | |
527 | { | |
528 | struct got_entry *got, *e; | |
529 | ||
530 | if (!*okp) | |
531 | return 0; | |
532 | ||
533 | got = (void *) mod->arch.got->sh_addr; | |
534 | for (e = got; e < got + mod->arch.next_got_entry; ++e) | |
535 | if (e->val == value) | |
536 | goto found; | |
537 | ||
538 | /* Not enough GOT entries? */ | |
80a03e29 | 539 | BUG_ON(e >= (struct got_entry *) (mod->arch.got->sh_addr + mod->arch.got->sh_size)); |
1da177e4 LT |
540 | |
541 | e->val = value; | |
542 | ++mod->arch.next_got_entry; | |
543 | found: | |
544 | return (uint64_t) e - mod->arch.gp; | |
545 | } | |
546 | ||
547 | static inline int | |
548 | gp_addressable (struct module *mod, uint64_t value) | |
549 | { | |
550 | return value - mod->arch.gp + MAX_LTOFF/2 < MAX_LTOFF; | |
551 | } | |
552 | ||
553 | /* Get PC-relative PLT entry for this value. Returns 0 on failure. */ | |
554 | static uint64_t | |
555 | get_plt (struct module *mod, const struct insn *insn, uint64_t value, int *okp) | |
556 | { | |
557 | struct plt_entry *plt, *plt_end; | |
558 | uint64_t target_ip, target_gp; | |
559 | ||
560 | if (!*okp) | |
561 | return 0; | |
562 | ||
563 | if (in_init(mod, (uint64_t) insn)) { | |
564 | plt = (void *) mod->arch.init_plt->sh_addr; | |
565 | plt_end = (void *) plt + mod->arch.init_plt->sh_size; | |
566 | } else { | |
567 | plt = (void *) mod->arch.core_plt->sh_addr; | |
568 | plt_end = (void *) plt + mod->arch.core_plt->sh_size; | |
569 | } | |
570 | ||
571 | /* "value" is a pointer to a function-descriptor; fetch the target ip/gp from it: */ | |
572 | target_ip = ((uint64_t *) value)[0]; | |
573 | target_gp = ((uint64_t *) value)[1]; | |
574 | ||
575 | /* Look for existing PLT entry. */ | |
576 | while (plt->bundle[0][0]) { | |
577 | if (plt_target(plt) == target_ip) | |
578 | goto found; | |
579 | if (++plt >= plt_end) | |
580 | BUG(); | |
581 | } | |
582 | *plt = ia64_plt_template; | |
583 | if (!patch_plt(mod, plt, target_ip, target_gp)) { | |
584 | *okp = 0; | |
585 | return 0; | |
586 | } | |
587 | #if ARCH_MODULE_DEBUG | |
588 | if (plt_target(plt) != target_ip) { | |
589 | printk("%s: mistargeted PLT: wanted %lx, got %lx\n", | |
d4ed8084 | 590 | __func__, target_ip, plt_target(plt)); |
1da177e4 LT |
591 | *okp = 0; |
592 | return 0; | |
593 | } | |
594 | #endif | |
595 | found: | |
596 | return (uint64_t) plt; | |
597 | } | |
598 | ||
599 | /* Get function descriptor for VALUE. */ | |
600 | static uint64_t | |
601 | get_fdesc (struct module *mod, uint64_t value, int *okp) | |
602 | { | |
603 | struct fdesc *fdesc = (void *) mod->arch.opd->sh_addr; | |
604 | ||
605 | if (!*okp) | |
606 | return 0; | |
607 | ||
608 | if (!value) { | |
609 | printk(KERN_ERR "%s: fdesc for zero requested!\n", mod->name); | |
610 | return 0; | |
611 | } | |
612 | ||
613 | if (!is_internal(mod, value)) | |
614 | /* | |
615 | * If it's not a module-local entry-point, "value" already points to a | |
616 | * function-descriptor. | |
617 | */ | |
618 | return value; | |
619 | ||
620 | /* Look for existing function descriptor. */ | |
621 | while (fdesc->ip) { | |
622 | if (fdesc->ip == value) | |
623 | return (uint64_t)fdesc; | |
624 | if ((uint64_t) ++fdesc >= mod->arch.opd->sh_addr + mod->arch.opd->sh_size) | |
625 | BUG(); | |
626 | } | |
627 | ||
628 | /* Create new one */ | |
629 | fdesc->ip = value; | |
630 | fdesc->gp = mod->arch.gp; | |
631 | return (uint64_t) fdesc; | |
632 | } | |
633 | ||
634 | static inline int | |
635 | do_reloc (struct module *mod, uint8_t r_type, Elf64_Sym *sym, uint64_t addend, | |
636 | Elf64_Shdr *sec, void *location) | |
637 | { | |
638 | enum reloc_target_format format = (r_type >> FORMAT_SHIFT) & FORMAT_MASK; | |
639 | enum reloc_value_formula formula = (r_type >> VALUE_SHIFT) & VALUE_MASK; | |
640 | uint64_t val; | |
641 | int ok = 1; | |
642 | ||
643 | val = sym->st_value + addend; | |
644 | ||
645 | switch (formula) { | |
646 | case RV_SEGREL: /* segment base is arbitrarily chosen to be 0 for kernel modules */ | |
647 | case RV_DIRECT: | |
648 | break; | |
649 | ||
650 | case RV_GPREL: val -= mod->arch.gp; break; | |
651 | case RV_LTREL: val = get_ltoff(mod, val, &ok); break; | |
652 | case RV_PLTREL: val = get_plt(mod, location, val, &ok); break; | |
653 | case RV_FPTR: val = get_fdesc(mod, val, &ok); break; | |
654 | case RV_SECREL: val -= sec->sh_addr; break; | |
655 | case RV_LTREL_FPTR: val = get_ltoff(mod, get_fdesc(mod, val, &ok), &ok); break; | |
656 | ||
657 | case RV_PCREL: | |
658 | switch (r_type) { | |
659 | case R_IA64_PCREL21B: | |
660 | if ((in_init(mod, val) && in_core(mod, (uint64_t)location)) || | |
661 | (in_core(mod, val) && in_init(mod, (uint64_t)location))) { | |
662 | /* | |
663 | * Init section may have been allocated far away from core, | |
664 | * if the branch won't reach, then allocate a plt for it. | |
665 | */ | |
666 | uint64_t delta = ((int64_t)val - (int64_t)location) / 16; | |
667 | if (delta + (1 << 20) >= (1 << 21)) { | |
668 | val = get_fdesc(mod, val, &ok); | |
669 | val = get_plt(mod, location, val, &ok); | |
670 | } | |
671 | } else if (!is_internal(mod, val)) | |
672 | val = get_plt(mod, location, val, &ok); | |
673 | /* FALL THROUGH */ | |
674 | default: | |
675 | val -= bundle(location); | |
676 | break; | |
677 | ||
678 | case R_IA64_PCREL32MSB: | |
679 | case R_IA64_PCREL32LSB: | |
680 | case R_IA64_PCREL64MSB: | |
681 | case R_IA64_PCREL64LSB: | |
682 | val -= (uint64_t) location; | |
683 | break; | |
684 | ||
685 | } | |
686 | switch (r_type) { | |
687 | case R_IA64_PCREL60B: format = RF_INSN60; break; | |
688 | case R_IA64_PCREL21B: format = RF_INSN21B; break; | |
689 | case R_IA64_PCREL21M: format = RF_INSN21M; break; | |
690 | case R_IA64_PCREL21F: format = RF_INSN21F; break; | |
691 | default: break; | |
692 | } | |
693 | break; | |
694 | ||
695 | case RV_BDREL: | |
696 | val -= (uint64_t) (in_init(mod, val) ? mod->module_init : mod->module_core); | |
697 | break; | |
698 | ||
699 | case RV_LTV: | |
700 | /* can link-time value relocs happen here? */ | |
701 | BUG(); | |
702 | break; | |
703 | ||
704 | case RV_PCREL2: | |
705 | if (r_type == R_IA64_PCREL21BI) { | |
706 | if (!is_internal(mod, val)) { | |
e088a4ad MW |
707 | printk(KERN_ERR "%s: %s reloc against " |
708 | "non-local symbol (%lx)\n", __func__, | |
709 | reloc_name[r_type], (unsigned long)val); | |
1da177e4 LT |
710 | return -ENOEXEC; |
711 | } | |
712 | format = RF_INSN21B; | |
713 | } | |
714 | val -= bundle(location); | |
715 | break; | |
716 | ||
717 | case RV_SPECIAL: | |
718 | switch (r_type) { | |
719 | case R_IA64_IPLTMSB: | |
720 | case R_IA64_IPLTLSB: | |
721 | val = get_fdesc(mod, get_plt(mod, location, val, &ok), &ok); | |
722 | format = RF_64LSB; | |
723 | if (r_type == R_IA64_IPLTMSB) | |
724 | format = RF_64MSB; | |
725 | break; | |
726 | ||
727 | case R_IA64_SUB: | |
728 | val = addend - sym->st_value; | |
729 | format = RF_INSN64; | |
730 | break; | |
731 | ||
732 | case R_IA64_LTOFF22X: | |
733 | if (gp_addressable(mod, val)) | |
734 | val -= mod->arch.gp; | |
735 | else | |
736 | val = get_ltoff(mod, val, &ok); | |
737 | format = RF_INSN22; | |
738 | break; | |
739 | ||
740 | case R_IA64_LDXMOV: | |
741 | if (gp_addressable(mod, val)) { | |
742 | /* turn "ld8" into "mov": */ | |
d4ed8084 | 743 | DEBUGP("%s: patching ld8 at %p to mov\n", __func__, location); |
1da177e4 LT |
744 | ia64_patch((u64) location, 0x1fff80fe000UL, 0x10000000000UL); |
745 | } | |
746 | return 0; | |
747 | ||
748 | default: | |
749 | if (reloc_name[r_type]) | |
750 | printk(KERN_ERR "%s: special reloc %s not supported", | |
751 | mod->name, reloc_name[r_type]); | |
752 | else | |
753 | printk(KERN_ERR "%s: unknown special reloc %x\n", | |
754 | mod->name, r_type); | |
755 | return -ENOEXEC; | |
756 | } | |
757 | break; | |
758 | ||
759 | case RV_TPREL: | |
760 | case RV_LTREL_TPREL: | |
761 | case RV_DTPMOD: | |
762 | case RV_LTREL_DTPMOD: | |
763 | case RV_DTPREL: | |
764 | case RV_LTREL_DTPREL: | |
765 | printk(KERN_ERR "%s: %s reloc not supported\n", | |
766 | mod->name, reloc_name[r_type] ? reloc_name[r_type] : "?"); | |
767 | return -ENOEXEC; | |
768 | ||
769 | default: | |
770 | printk(KERN_ERR "%s: unknown reloc %x\n", mod->name, r_type); | |
771 | return -ENOEXEC; | |
772 | } | |
773 | ||
774 | if (!ok) | |
775 | return -ENOEXEC; | |
776 | ||
d4ed8084 | 777 | DEBUGP("%s: [%p]<-%016lx = %s(%lx)\n", __func__, location, val, |
1da177e4 LT |
778 | reloc_name[r_type] ? reloc_name[r_type] : "?", sym->st_value + addend); |
779 | ||
780 | switch (format) { | |
781 | case RF_INSN21B: ok = apply_imm21b(mod, location, (int64_t) val / 16); break; | |
782 | case RF_INSN22: ok = apply_imm22(mod, location, val); break; | |
783 | case RF_INSN64: ok = apply_imm64(mod, location, val); break; | |
784 | case RF_INSN60: ok = apply_imm60(mod, location, (int64_t) val / 16); break; | |
785 | case RF_32LSB: put_unaligned(val, (uint32_t *) location); break; | |
786 | case RF_64LSB: put_unaligned(val, (uint64_t *) location); break; | |
787 | case RF_32MSB: /* ia64 Linux is little-endian... */ | |
788 | case RF_64MSB: /* ia64 Linux is little-endian... */ | |
789 | case RF_INSN14: /* must be within-module, i.e., resolved by "ld -r" */ | |
790 | case RF_INSN21M: /* must be within-module, i.e., resolved by "ld -r" */ | |
791 | case RF_INSN21F: /* must be within-module, i.e., resolved by "ld -r" */ | |
792 | printk(KERN_ERR "%s: format %u needed by %s reloc is not supported\n", | |
793 | mod->name, format, reloc_name[r_type] ? reloc_name[r_type] : "?"); | |
794 | return -ENOEXEC; | |
795 | ||
796 | default: | |
797 | printk(KERN_ERR "%s: relocation %s resulted in unknown format %u\n", | |
798 | mod->name, reloc_name[r_type] ? reloc_name[r_type] : "?", format); | |
799 | return -ENOEXEC; | |
800 | } | |
801 | return ok ? 0 : -ENOEXEC; | |
802 | } | |
803 | ||
804 | int | |
805 | apply_relocate_add (Elf64_Shdr *sechdrs, const char *strtab, unsigned int symindex, | |
806 | unsigned int relsec, struct module *mod) | |
807 | { | |
808 | unsigned int i, n = sechdrs[relsec].sh_size / sizeof(Elf64_Rela); | |
809 | Elf64_Rela *rela = (void *) sechdrs[relsec].sh_addr; | |
810 | Elf64_Shdr *target_sec; | |
811 | int ret; | |
812 | ||
d4ed8084 | 813 | DEBUGP("%s: applying section %u (%u relocs) to %u\n", __func__, |
1da177e4 LT |
814 | relsec, n, sechdrs[relsec].sh_info); |
815 | ||
816 | target_sec = sechdrs + sechdrs[relsec].sh_info; | |
817 | ||
818 | if (target_sec->sh_entsize == ~0UL) | |
819 | /* | |
820 | * If target section wasn't allocated, we don't need to relocate it. | |
821 | * Happens, e.g., for debug sections. | |
822 | */ | |
823 | return 0; | |
824 | ||
825 | if (!mod->arch.gp) { | |
826 | /* | |
827 | * XXX Should have an arch-hook for running this after final section | |
828 | * addresses have been selected... | |
829 | */ | |
866ba633 KO |
830 | uint64_t gp; |
831 | if (mod->core_size > MAX_LTOFF) | |
1da177e4 LT |
832 | /* |
833 | * This takes advantage of fact that SHF_ARCH_SMALL gets allocated | |
834 | * at the end of the module. | |
835 | */ | |
866ba633 KO |
836 | gp = mod->core_size - MAX_LTOFF / 2; |
837 | else | |
838 | gp = mod->core_size / 2; | |
839 | gp = (uint64_t) mod->module_core + ((gp + 7) & -8); | |
1da177e4 | 840 | mod->arch.gp = gp; |
d4ed8084 | 841 | DEBUGP("%s: placing gp at 0x%lx\n", __func__, gp); |
1da177e4 LT |
842 | } |
843 | ||
844 | for (i = 0; i < n; i++) { | |
845 | ret = do_reloc(mod, ELF64_R_TYPE(rela[i].r_info), | |
846 | ((Elf64_Sym *) sechdrs[symindex].sh_addr | |
847 | + ELF64_R_SYM(rela[i].r_info)), | |
848 | rela[i].r_addend, target_sec, | |
849 | (void *) target_sec->sh_addr + rela[i].r_offset); | |
850 | if (ret < 0) | |
851 | return ret; | |
852 | } | |
853 | return 0; | |
854 | } | |
855 | ||
856 | int | |
857 | apply_relocate (Elf64_Shdr *sechdrs, const char *strtab, unsigned int symindex, | |
858 | unsigned int relsec, struct module *mod) | |
859 | { | |
860 | printk(KERN_ERR "module %s: REL relocs in section %u unsupported\n", mod->name, relsec); | |
861 | return -ENOEXEC; | |
862 | } | |
863 | ||
864 | /* | |
865 | * Modules contain a single unwind table which covers both the core and the init text | |
866 | * sections but since the two are not contiguous, we need to split this table up such that | |
72fdbdce | 867 | * we can register (and unregister) each "segment" separately. Fortunately, this sounds |
1da177e4 LT |
868 | * more complicated than it really is. |
869 | */ | |
870 | static void | |
871 | register_unwind_table (struct module *mod) | |
872 | { | |
873 | struct unw_table_entry *start = (void *) mod->arch.unwind->sh_addr; | |
874 | struct unw_table_entry *end = start + mod->arch.unwind->sh_size / sizeof (*start); | |
875 | struct unw_table_entry tmp, *e1, *e2, *core, *init; | |
876 | unsigned long num_init = 0, num_core = 0; | |
877 | ||
878 | /* First, count how many init and core unwind-table entries there are. */ | |
879 | for (e1 = start; e1 < end; ++e1) | |
880 | if (in_init(mod, e1->start_offset)) | |
881 | ++num_init; | |
882 | else | |
883 | ++num_core; | |
884 | /* | |
885 | * Second, sort the table such that all unwind-table entries for the init and core | |
886 | * text sections are nicely separated. We do this with a stupid bubble sort | |
887 | * (unwind tables don't get ridiculously huge). | |
888 | */ | |
889 | for (e1 = start; e1 < end; ++e1) { | |
890 | for (e2 = e1 + 1; e2 < end; ++e2) { | |
891 | if (e2->start_offset < e1->start_offset) { | |
892 | tmp = *e1; | |
893 | *e1 = *e2; | |
894 | *e2 = tmp; | |
895 | } | |
896 | } | |
897 | } | |
898 | /* | |
899 | * Third, locate the init and core segments in the unwind table: | |
900 | */ | |
901 | if (in_init(mod, start->start_offset)) { | |
902 | init = start; | |
903 | core = start + num_init; | |
904 | } else { | |
905 | core = start; | |
906 | init = start + num_core; | |
907 | } | |
908 | ||
d4ed8084 | 909 | DEBUGP("%s: name=%s, gp=%lx, num_init=%lu, num_core=%lu\n", __func__, |
1da177e4 LT |
910 | mod->name, mod->arch.gp, num_init, num_core); |
911 | ||
912 | /* | |
913 | * Fourth, register both tables (if not empty). | |
914 | */ | |
915 | if (num_core > 0) { | |
916 | mod->arch.core_unw_table = unw_add_unwind_table(mod->name, 0, mod->arch.gp, | |
917 | core, core + num_core); | |
d4ed8084 | 918 | DEBUGP("%s: core: handle=%p [%p-%p)\n", __func__, |
1da177e4 LT |
919 | mod->arch.core_unw_table, core, core + num_core); |
920 | } | |
921 | if (num_init > 0) { | |
922 | mod->arch.init_unw_table = unw_add_unwind_table(mod->name, 0, mod->arch.gp, | |
923 | init, init + num_init); | |
d4ed8084 | 924 | DEBUGP("%s: init: handle=%p [%p-%p)\n", __func__, |
1da177e4 LT |
925 | mod->arch.init_unw_table, init, init + num_init); |
926 | } | |
927 | } | |
928 | ||
929 | int | |
930 | module_finalize (const Elf_Ehdr *hdr, const Elf_Shdr *sechdrs, struct module *mod) | |
931 | { | |
d4ed8084 | 932 | DEBUGP("%s: init: entry=%p\n", __func__, mod->init); |
1da177e4 LT |
933 | if (mod->arch.unwind) |
934 | register_unwind_table(mod); | |
ee158fcd IY |
935 | #ifdef CONFIG_PARAVIRT |
936 | if (mod->arch.paravirt_bundles) { | |
937 | struct paravirt_patch_site_bundle *start = | |
938 | (struct paravirt_patch_site_bundle *) | |
939 | mod->arch.paravirt_bundles->sh_addr; | |
940 | struct paravirt_patch_site_bundle *end = | |
941 | (struct paravirt_patch_site_bundle *) | |
942 | (mod->arch.paravirt_bundles->sh_addr + | |
943 | mod->arch.paravirt_bundles->sh_size); | |
944 | ||
945 | paravirt_patch_apply_bundle(start, end); | |
946 | } | |
947 | if (mod->arch.paravirt_insts) { | |
948 | struct paravirt_patch_site_inst *start = | |
949 | (struct paravirt_patch_site_inst *) | |
950 | mod->arch.paravirt_insts->sh_addr; | |
951 | struct paravirt_patch_site_inst *end = | |
952 | (struct paravirt_patch_site_inst *) | |
953 | (mod->arch.paravirt_insts->sh_addr + | |
954 | mod->arch.paravirt_insts->sh_size); | |
955 | ||
956 | paravirt_patch_apply_inst(start, end); | |
957 | } | |
958 | #endif | |
1da177e4 LT |
959 | return 0; |
960 | } | |
961 | ||
962 | void | |
963 | module_arch_cleanup (struct module *mod) | |
964 | { | |
965 | if (mod->arch.init_unw_table) | |
966 | unw_remove_unwind_table(mod->arch.init_unw_table); | |
967 | if (mod->arch.core_unw_table) | |
968 | unw_remove_unwind_table(mod->arch.core_unw_table); | |
969 | } |