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b2441318 | 1 | // SPDX-License-Identifier: GPL-2.0 |
1da177e4 LT |
2 | /* |
3 | * IA-64-specific support for kernel module loader. | |
4 | * | |
5 | * Copyright (C) 2003 Hewlett-Packard Co | |
6 | * David Mosberger-Tang <davidm@hpl.hp.com> | |
7 | * | |
8 | * Loosely based on patch by Rusty Russell. | |
9 | */ | |
10 | ||
11 | /* relocs tested so far: | |
12 | ||
13 | DIR64LSB | |
14 | FPTR64LSB | |
15 | GPREL22 | |
16 | LDXMOV | |
17 | LDXMOV | |
18 | LTOFF22 | |
19 | LTOFF22X | |
20 | LTOFF22X | |
21 | LTOFF_FPTR22 | |
22 | PCREL21B (for br.call only; br.cond is not supported out of modules!) | |
23 | PCREL60B (for brl.cond only; brl.call is not supported for modules!) | |
24 | PCREL64LSB | |
25 | SECREL32LSB | |
26 | SEGREL64LSB | |
27 | */ | |
28 | ||
1da177e4 LT |
29 | |
30 | #include <linux/kernel.h> | |
31 | #include <linux/sched.h> | |
32 | #include <linux/elf.h> | |
33 | #include <linux/moduleloader.h> | |
34 | #include <linux/string.h> | |
35 | #include <linux/vmalloc.h> | |
36 | ||
37 | #include <asm/patch.h> | |
38 | #include <asm/unaligned.h> | |
8e307888 | 39 | #include <asm/sections.h> |
1da177e4 LT |
40 | |
41 | #define ARCH_MODULE_DEBUG 0 | |
42 | ||
43 | #if ARCH_MODULE_DEBUG | |
44 | # define DEBUGP printk | |
45 | # define inline | |
46 | #else | |
47 | # define DEBUGP(fmt , a...) | |
48 | #endif | |
49 | ||
50 | #ifdef CONFIG_ITANIUM | |
51 | # define USE_BRL 0 | |
52 | #else | |
53 | # define USE_BRL 1 | |
54 | #endif | |
55 | ||
56 | #define MAX_LTOFF ((uint64_t) (1 << 22)) /* max. allowable linkage-table offset */ | |
57 | ||
58 | /* Define some relocation helper macros/types: */ | |
59 | ||
60 | #define FORMAT_SHIFT 0 | |
61 | #define FORMAT_BITS 3 | |
62 | #define FORMAT_MASK ((1 << FORMAT_BITS) - 1) | |
63 | #define VALUE_SHIFT 3 | |
64 | #define VALUE_BITS 5 | |
65 | #define VALUE_MASK ((1 << VALUE_BITS) - 1) | |
66 | ||
67 | enum reloc_target_format { | |
68 | /* direct encoded formats: */ | |
69 | RF_NONE = 0, | |
70 | RF_INSN14 = 1, | |
71 | RF_INSN22 = 2, | |
72 | RF_INSN64 = 3, | |
73 | RF_32MSB = 4, | |
74 | RF_32LSB = 5, | |
75 | RF_64MSB = 6, | |
76 | RF_64LSB = 7, | |
77 | ||
78 | /* formats that cannot be directly decoded: */ | |
79 | RF_INSN60, | |
80 | RF_INSN21B, /* imm21 form 1 */ | |
81 | RF_INSN21M, /* imm21 form 2 */ | |
82 | RF_INSN21F /* imm21 form 3 */ | |
83 | }; | |
84 | ||
85 | enum reloc_value_formula { | |
86 | RV_DIRECT = 4, /* S + A */ | |
87 | RV_GPREL = 5, /* @gprel(S + A) */ | |
88 | RV_LTREL = 6, /* @ltoff(S + A) */ | |
89 | RV_PLTREL = 7, /* @pltoff(S + A) */ | |
90 | RV_FPTR = 8, /* @fptr(S + A) */ | |
91 | RV_PCREL = 9, /* S + A - P */ | |
92 | RV_LTREL_FPTR = 10, /* @ltoff(@fptr(S + A)) */ | |
93 | RV_SEGREL = 11, /* @segrel(S + A) */ | |
94 | RV_SECREL = 12, /* @secrel(S + A) */ | |
95 | RV_BDREL = 13, /* BD + A */ | |
96 | RV_LTV = 14, /* S + A (like RV_DIRECT, except frozen at static link-time) */ | |
97 | RV_PCREL2 = 15, /* S + A - P */ | |
98 | RV_SPECIAL = 16, /* various (see below) */ | |
99 | RV_RSVD17 = 17, | |
100 | RV_TPREL = 18, /* @tprel(S + A) */ | |
101 | RV_LTREL_TPREL = 19, /* @ltoff(@tprel(S + A)) */ | |
102 | RV_DTPMOD = 20, /* @dtpmod(S + A) */ | |
103 | RV_LTREL_DTPMOD = 21, /* @ltoff(@dtpmod(S + A)) */ | |
104 | RV_DTPREL = 22, /* @dtprel(S + A) */ | |
105 | RV_LTREL_DTPREL = 23, /* @ltoff(@dtprel(S + A)) */ | |
106 | RV_RSVD24 = 24, | |
107 | RV_RSVD25 = 25, | |
108 | RV_RSVD26 = 26, | |
109 | RV_RSVD27 = 27 | |
110 | /* 28-31 reserved for implementation-specific purposes. */ | |
111 | }; | |
112 | ||
113 | #define N(reloc) [R_IA64_##reloc] = #reloc | |
114 | ||
115 | static const char *reloc_name[256] = { | |
116 | N(NONE), N(IMM14), N(IMM22), N(IMM64), | |
117 | N(DIR32MSB), N(DIR32LSB), N(DIR64MSB), N(DIR64LSB), | |
118 | N(GPREL22), N(GPREL64I), N(GPREL32MSB), N(GPREL32LSB), | |
119 | N(GPREL64MSB), N(GPREL64LSB), N(LTOFF22), N(LTOFF64I), | |
120 | N(PLTOFF22), N(PLTOFF64I), N(PLTOFF64MSB), N(PLTOFF64LSB), | |
121 | N(FPTR64I), N(FPTR32MSB), N(FPTR32LSB), N(FPTR64MSB), | |
122 | N(FPTR64LSB), N(PCREL60B), N(PCREL21B), N(PCREL21M), | |
123 | N(PCREL21F), N(PCREL32MSB), N(PCREL32LSB), N(PCREL64MSB), | |
124 | N(PCREL64LSB), N(LTOFF_FPTR22), N(LTOFF_FPTR64I), N(LTOFF_FPTR32MSB), | |
125 | N(LTOFF_FPTR32LSB), N(LTOFF_FPTR64MSB), N(LTOFF_FPTR64LSB), N(SEGREL32MSB), | |
126 | N(SEGREL32LSB), N(SEGREL64MSB), N(SEGREL64LSB), N(SECREL32MSB), | |
127 | N(SECREL32LSB), N(SECREL64MSB), N(SECREL64LSB), N(REL32MSB), | |
128 | N(REL32LSB), N(REL64MSB), N(REL64LSB), N(LTV32MSB), | |
129 | N(LTV32LSB), N(LTV64MSB), N(LTV64LSB), N(PCREL21BI), | |
130 | N(PCREL22), N(PCREL64I), N(IPLTMSB), N(IPLTLSB), | |
131 | N(COPY), N(LTOFF22X), N(LDXMOV), N(TPREL14), | |
132 | N(TPREL22), N(TPREL64I), N(TPREL64MSB), N(TPREL64LSB), | |
133 | N(LTOFF_TPREL22), N(DTPMOD64MSB), N(DTPMOD64LSB), N(LTOFF_DTPMOD22), | |
134 | N(DTPREL14), N(DTPREL22), N(DTPREL64I), N(DTPREL32MSB), | |
135 | N(DTPREL32LSB), N(DTPREL64MSB), N(DTPREL64LSB), N(LTOFF_DTPREL22) | |
136 | }; | |
137 | ||
138 | #undef N | |
139 | ||
1da177e4 LT |
140 | /* Opaque struct for insns, to protect against derefs. */ |
141 | struct insn; | |
142 | ||
143 | static inline uint64_t | |
144 | bundle (const struct insn *insn) | |
145 | { | |
146 | return (uint64_t) insn & ~0xfUL; | |
147 | } | |
148 | ||
149 | static inline int | |
150 | slot (const struct insn *insn) | |
151 | { | |
152 | return (uint64_t) insn & 0x3; | |
153 | } | |
154 | ||
155 | static int | |
156 | apply_imm64 (struct module *mod, struct insn *insn, uint64_t val) | |
157 | { | |
a25fb850 | 158 | if (slot(insn) != 1 && slot(insn) != 2) { |
1da177e4 LT |
159 | printk(KERN_ERR "%s: invalid slot number %d for IMM64\n", |
160 | mod->name, slot(insn)); | |
161 | return 0; | |
162 | } | |
163 | ia64_patch_imm64((u64) insn, val); | |
164 | return 1; | |
165 | } | |
166 | ||
167 | static int | |
168 | apply_imm60 (struct module *mod, struct insn *insn, uint64_t val) | |
169 | { | |
a25fb850 | 170 | if (slot(insn) != 1 && slot(insn) != 2) { |
1da177e4 LT |
171 | printk(KERN_ERR "%s: invalid slot number %d for IMM60\n", |
172 | mod->name, slot(insn)); | |
173 | return 0; | |
174 | } | |
175 | if (val + ((uint64_t) 1 << 59) >= (1UL << 60)) { | |
e088a4ad MW |
176 | printk(KERN_ERR "%s: value %ld out of IMM60 range\n", |
177 | mod->name, (long) val); | |
1da177e4 LT |
178 | return 0; |
179 | } | |
180 | ia64_patch_imm60((u64) insn, val); | |
181 | return 1; | |
182 | } | |
183 | ||
184 | static int | |
185 | apply_imm22 (struct module *mod, struct insn *insn, uint64_t val) | |
186 | { | |
187 | if (val + (1 << 21) >= (1 << 22)) { | |
e088a4ad MW |
188 | printk(KERN_ERR "%s: value %li out of IMM22 range\n", |
189 | mod->name, (long)val); | |
1da177e4 LT |
190 | return 0; |
191 | } | |
192 | ia64_patch((u64) insn, 0x01fffcfe000UL, ( ((val & 0x200000UL) << 15) /* bit 21 -> 36 */ | |
193 | | ((val & 0x1f0000UL) << 6) /* bit 16 -> 22 */ | |
194 | | ((val & 0x00ff80UL) << 20) /* bit 7 -> 27 */ | |
195 | | ((val & 0x00007fUL) << 13) /* bit 0 -> 13 */)); | |
196 | return 1; | |
197 | } | |
198 | ||
199 | static int | |
200 | apply_imm21b (struct module *mod, struct insn *insn, uint64_t val) | |
201 | { | |
202 | if (val + (1 << 20) >= (1 << 21)) { | |
e088a4ad MW |
203 | printk(KERN_ERR "%s: value %li out of IMM21b range\n", |
204 | mod->name, (long)val); | |
1da177e4 LT |
205 | return 0; |
206 | } | |
207 | ia64_patch((u64) insn, 0x11ffffe000UL, ( ((val & 0x100000UL) << 16) /* bit 20 -> 36 */ | |
208 | | ((val & 0x0fffffUL) << 13) /* bit 0 -> 13 */)); | |
209 | return 1; | |
210 | } | |
211 | ||
212 | #if USE_BRL | |
213 | ||
214 | struct plt_entry { | |
215 | /* Three instruction bundles in PLT. */ | |
216 | unsigned char bundle[2][16]; | |
217 | }; | |
218 | ||
219 | static const struct plt_entry ia64_plt_template = { | |
220 | { | |
221 | { | |
222 | 0x04, 0x00, 0x00, 0x00, 0x01, 0x00, /* [MLX] nop.m 0 */ | |
223 | 0x00, 0x00, 0x00, 0x00, 0x00, 0x20, /* movl gp=TARGET_GP */ | |
224 | 0x00, 0x00, 0x00, 0x60 | |
225 | }, | |
226 | { | |
227 | 0x05, 0x00, 0x00, 0x00, 0x01, 0x00, /* [MLX] nop.m 0 */ | |
228 | 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, /* brl.many gp=TARGET_GP */ | |
229 | 0x08, 0x00, 0x00, 0xc0 | |
230 | } | |
231 | } | |
232 | }; | |
233 | ||
234 | static int | |
235 | patch_plt (struct module *mod, struct plt_entry *plt, long target_ip, unsigned long target_gp) | |
236 | { | |
237 | if (apply_imm64(mod, (struct insn *) (plt->bundle[0] + 2), target_gp) | |
238 | && apply_imm60(mod, (struct insn *) (plt->bundle[1] + 2), | |
239 | (target_ip - (int64_t) plt->bundle[1]) / 16)) | |
240 | return 1; | |
241 | return 0; | |
242 | } | |
243 | ||
244 | unsigned long | |
245 | plt_target (struct plt_entry *plt) | |
246 | { | |
247 | uint64_t b0, b1, *b = (uint64_t *) plt->bundle[1]; | |
248 | long off; | |
249 | ||
250 | b0 = b[0]; b1 = b[1]; | |
251 | off = ( ((b1 & 0x00fffff000000000UL) >> 36) /* imm20b -> bit 0 */ | |
252 | | ((b0 >> 48) << 20) | ((b1 & 0x7fffffUL) << 36) /* imm39 -> bit 20 */ | |
253 | | ((b1 & 0x0800000000000000UL) << 0)); /* i -> bit 59 */ | |
254 | return (long) plt->bundle[1] + 16*off; | |
255 | } | |
256 | ||
257 | #else /* !USE_BRL */ | |
258 | ||
259 | struct plt_entry { | |
260 | /* Three instruction bundles in PLT. */ | |
261 | unsigned char bundle[3][16]; | |
262 | }; | |
263 | ||
264 | static const struct plt_entry ia64_plt_template = { | |
265 | { | |
266 | { | |
267 | 0x05, 0x00, 0x00, 0x00, 0x01, 0x00, /* [MLX] nop.m 0 */ | |
268 | 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, /* movl r16=TARGET_IP */ | |
269 | 0x02, 0x00, 0x00, 0x60 | |
270 | }, | |
271 | { | |
272 | 0x04, 0x00, 0x00, 0x00, 0x01, 0x00, /* [MLX] nop.m 0 */ | |
273 | 0x00, 0x00, 0x00, 0x00, 0x00, 0x20, /* movl gp=TARGET_GP */ | |
274 | 0x00, 0x00, 0x00, 0x60 | |
275 | }, | |
276 | { | |
277 | 0x11, 0x00, 0x00, 0x00, 0x01, 0x00, /* [MIB] nop.m 0 */ | |
278 | 0x60, 0x80, 0x04, 0x80, 0x03, 0x00, /* mov b6=r16 */ | |
279 | 0x60, 0x00, 0x80, 0x00 /* br.few b6 */ | |
280 | } | |
281 | } | |
282 | }; | |
283 | ||
284 | static int | |
285 | patch_plt (struct module *mod, struct plt_entry *plt, long target_ip, unsigned long target_gp) | |
286 | { | |
287 | if (apply_imm64(mod, (struct insn *) (plt->bundle[0] + 2), target_ip) | |
288 | && apply_imm64(mod, (struct insn *) (plt->bundle[1] + 2), target_gp)) | |
289 | return 1; | |
290 | return 0; | |
291 | } | |
292 | ||
293 | unsigned long | |
294 | plt_target (struct plt_entry *plt) | |
295 | { | |
296 | uint64_t b0, b1, *b = (uint64_t *) plt->bundle[0]; | |
297 | ||
298 | b0 = b[0]; b1 = b[1]; | |
299 | return ( ((b1 & 0x000007f000000000) >> 36) /* imm7b -> bit 0 */ | |
300 | | ((b1 & 0x07fc000000000000) >> 43) /* imm9d -> bit 7 */ | |
301 | | ((b1 & 0x0003e00000000000) >> 29) /* imm5c -> bit 16 */ | |
302 | | ((b1 & 0x0000100000000000) >> 23) /* ic -> bit 21 */ | |
303 | | ((b0 >> 46) << 22) | ((b1 & 0x7fffff) << 40) /* imm41 -> bit 22 */ | |
304 | | ((b1 & 0x0800000000000000) << 4)); /* i -> bit 63 */ | |
305 | } | |
306 | ||
307 | #endif /* !USE_BRL */ | |
308 | ||
1da177e4 | 309 | void |
d453cded | 310 | module_arch_freeing_init (struct module *mod) |
1da177e4 | 311 | { |
d453cded | 312 | if (mod->arch.init_unw_table) { |
1da177e4 LT |
313 | unw_remove_unwind_table(mod->arch.init_unw_table); |
314 | mod->arch.init_unw_table = NULL; | |
315 | } | |
1da177e4 LT |
316 | } |
317 | ||
318 | /* Have we already seen one of these relocations? */ | |
319 | /* FIXME: we could look in other sections, too --RR */ | |
320 | static int | |
321 | duplicate_reloc (const Elf64_Rela *rela, unsigned int num) | |
322 | { | |
323 | unsigned int i; | |
324 | ||
325 | for (i = 0; i < num; i++) { | |
326 | if (rela[i].r_info == rela[num].r_info && rela[i].r_addend == rela[num].r_addend) | |
327 | return 1; | |
328 | } | |
329 | return 0; | |
330 | } | |
331 | ||
332 | /* Count how many GOT entries we may need */ | |
333 | static unsigned int | |
334 | count_gots (const Elf64_Rela *rela, unsigned int num) | |
335 | { | |
336 | unsigned int i, ret = 0; | |
337 | ||
338 | /* Sure, this is order(n^2), but it's usually short, and not | |
339 | time critical */ | |
340 | for (i = 0; i < num; i++) { | |
341 | switch (ELF64_R_TYPE(rela[i].r_info)) { | |
342 | case R_IA64_LTOFF22: | |
343 | case R_IA64_LTOFF22X: | |
344 | case R_IA64_LTOFF64I: | |
345 | case R_IA64_LTOFF_FPTR22: | |
346 | case R_IA64_LTOFF_FPTR64I: | |
347 | case R_IA64_LTOFF_FPTR32MSB: | |
348 | case R_IA64_LTOFF_FPTR32LSB: | |
349 | case R_IA64_LTOFF_FPTR64MSB: | |
350 | case R_IA64_LTOFF_FPTR64LSB: | |
351 | if (!duplicate_reloc(rela, i)) | |
352 | ret++; | |
353 | break; | |
354 | } | |
355 | } | |
356 | return ret; | |
357 | } | |
358 | ||
359 | /* Count how many PLT entries we may need */ | |
360 | static unsigned int | |
361 | count_plts (const Elf64_Rela *rela, unsigned int num) | |
362 | { | |
363 | unsigned int i, ret = 0; | |
364 | ||
365 | /* Sure, this is order(n^2), but it's usually short, and not | |
366 | time critical */ | |
367 | for (i = 0; i < num; i++) { | |
368 | switch (ELF64_R_TYPE(rela[i].r_info)) { | |
369 | case R_IA64_PCREL21B: | |
370 | case R_IA64_PLTOFF22: | |
371 | case R_IA64_PLTOFF64I: | |
372 | case R_IA64_PLTOFF64MSB: | |
373 | case R_IA64_PLTOFF64LSB: | |
374 | case R_IA64_IPLTMSB: | |
375 | case R_IA64_IPLTLSB: | |
376 | if (!duplicate_reloc(rela, i)) | |
377 | ret++; | |
378 | break; | |
379 | } | |
380 | } | |
381 | return ret; | |
382 | } | |
383 | ||
384 | /* We need to create an function-descriptors for any internal function | |
385 | which is referenced. */ | |
386 | static unsigned int | |
387 | count_fdescs (const Elf64_Rela *rela, unsigned int num) | |
388 | { | |
389 | unsigned int i, ret = 0; | |
390 | ||
391 | /* Sure, this is order(n^2), but it's usually short, and not time critical. */ | |
392 | for (i = 0; i < num; i++) { | |
393 | switch (ELF64_R_TYPE(rela[i].r_info)) { | |
394 | case R_IA64_FPTR64I: | |
395 | case R_IA64_FPTR32LSB: | |
396 | case R_IA64_FPTR32MSB: | |
397 | case R_IA64_FPTR64LSB: | |
398 | case R_IA64_FPTR64MSB: | |
399 | case R_IA64_LTOFF_FPTR22: | |
400 | case R_IA64_LTOFF_FPTR32LSB: | |
401 | case R_IA64_LTOFF_FPTR32MSB: | |
402 | case R_IA64_LTOFF_FPTR64I: | |
403 | case R_IA64_LTOFF_FPTR64LSB: | |
404 | case R_IA64_LTOFF_FPTR64MSB: | |
405 | case R_IA64_IPLTMSB: | |
406 | case R_IA64_IPLTLSB: | |
407 | /* | |
408 | * Jumps to static functions sometimes go straight to their | |
409 | * offset. Of course, that may not be possible if the jump is | |
410 | * from init -> core or vice. versa, so we need to generate an | |
411 | * FDESC (and PLT etc) for that. | |
412 | */ | |
413 | case R_IA64_PCREL21B: | |
414 | if (!duplicate_reloc(rela, i)) | |
415 | ret++; | |
416 | break; | |
417 | } | |
418 | } | |
419 | return ret; | |
420 | } | |
421 | ||
422 | int | |
423 | module_frob_arch_sections (Elf_Ehdr *ehdr, Elf_Shdr *sechdrs, char *secstrings, | |
424 | struct module *mod) | |
425 | { | |
426 | unsigned long core_plts = 0, init_plts = 0, gots = 0, fdescs = 0; | |
427 | Elf64_Shdr *s, *sechdrs_end = sechdrs + ehdr->e_shnum; | |
428 | ||
429 | /* | |
430 | * To store the PLTs and function-descriptors, we expand the .text section for | |
431 | * core module-code and the .init.text section for initialization code. | |
432 | */ | |
433 | for (s = sechdrs; s < sechdrs_end; ++s) | |
434 | if (strcmp(".core.plt", secstrings + s->sh_name) == 0) | |
435 | mod->arch.core_plt = s; | |
436 | else if (strcmp(".init.plt", secstrings + s->sh_name) == 0) | |
437 | mod->arch.init_plt = s; | |
438 | else if (strcmp(".got", secstrings + s->sh_name) == 0) | |
439 | mod->arch.got = s; | |
440 | else if (strcmp(".opd", secstrings + s->sh_name) == 0) | |
441 | mod->arch.opd = s; | |
442 | else if (strcmp(".IA_64.unwind", secstrings + s->sh_name) == 0) | |
443 | mod->arch.unwind = s; | |
444 | ||
445 | if (!mod->arch.core_plt || !mod->arch.init_plt || !mod->arch.got || !mod->arch.opd) { | |
446 | printk(KERN_ERR "%s: sections missing\n", mod->name); | |
447 | return -ENOEXEC; | |
448 | } | |
449 | ||
450 | /* GOT and PLTs can occur in any relocated section... */ | |
451 | for (s = sechdrs + 1; s < sechdrs_end; ++s) { | |
452 | const Elf64_Rela *rels = (void *)ehdr + s->sh_offset; | |
453 | unsigned long numrels = s->sh_size/sizeof(Elf64_Rela); | |
454 | ||
455 | if (s->sh_type != SHT_RELA) | |
456 | continue; | |
457 | ||
458 | gots += count_gots(rels, numrels); | |
459 | fdescs += count_fdescs(rels, numrels); | |
460 | if (strstr(secstrings + s->sh_name, ".init")) | |
461 | init_plts += count_plts(rels, numrels); | |
462 | else | |
463 | core_plts += count_plts(rels, numrels); | |
464 | } | |
465 | ||
466 | mod->arch.core_plt->sh_type = SHT_NOBITS; | |
467 | mod->arch.core_plt->sh_flags = SHF_EXECINSTR | SHF_ALLOC; | |
468 | mod->arch.core_plt->sh_addralign = 16; | |
469 | mod->arch.core_plt->sh_size = core_plts * sizeof(struct plt_entry); | |
470 | mod->arch.init_plt->sh_type = SHT_NOBITS; | |
471 | mod->arch.init_plt->sh_flags = SHF_EXECINSTR | SHF_ALLOC; | |
472 | mod->arch.init_plt->sh_addralign = 16; | |
473 | mod->arch.init_plt->sh_size = init_plts * sizeof(struct plt_entry); | |
474 | mod->arch.got->sh_type = SHT_NOBITS; | |
475 | mod->arch.got->sh_flags = ARCH_SHF_SMALL | SHF_ALLOC; | |
476 | mod->arch.got->sh_addralign = 8; | |
477 | mod->arch.got->sh_size = gots * sizeof(struct got_entry); | |
478 | mod->arch.opd->sh_type = SHT_NOBITS; | |
479 | mod->arch.opd->sh_flags = SHF_ALLOC; | |
480 | mod->arch.opd->sh_addralign = 8; | |
481 | mod->arch.opd->sh_size = fdescs * sizeof(struct fdesc); | |
482 | DEBUGP("%s: core.plt=%lx, init.plt=%lx, got=%lx, fdesc=%lx\n", | |
d4ed8084 | 483 | __func__, mod->arch.core_plt->sh_size, mod->arch.init_plt->sh_size, |
1da177e4 LT |
484 | mod->arch.got->sh_size, mod->arch.opd->sh_size); |
485 | return 0; | |
486 | } | |
487 | ||
488 | static inline int | |
489 | in_init (const struct module *mod, uint64_t addr) | |
490 | { | |
7523e4dc | 491 | return addr - (uint64_t) mod->init_layout.base < mod->init_layout.size; |
1da177e4 LT |
492 | } |
493 | ||
494 | static inline int | |
495 | in_core (const struct module *mod, uint64_t addr) | |
496 | { | |
7523e4dc | 497 | return addr - (uint64_t) mod->core_layout.base < mod->core_layout.size; |
1da177e4 LT |
498 | } |
499 | ||
500 | static inline int | |
501 | is_internal (const struct module *mod, uint64_t value) | |
502 | { | |
503 | return in_init(mod, value) || in_core(mod, value); | |
504 | } | |
505 | ||
506 | /* | |
507 | * Get gp-relative offset for the linkage-table entry of VALUE. | |
508 | */ | |
509 | static uint64_t | |
510 | get_ltoff (struct module *mod, uint64_t value, int *okp) | |
511 | { | |
512 | struct got_entry *got, *e; | |
513 | ||
514 | if (!*okp) | |
515 | return 0; | |
516 | ||
517 | got = (void *) mod->arch.got->sh_addr; | |
518 | for (e = got; e < got + mod->arch.next_got_entry; ++e) | |
519 | if (e->val == value) | |
520 | goto found; | |
521 | ||
522 | /* Not enough GOT entries? */ | |
80a03e29 | 523 | BUG_ON(e >= (struct got_entry *) (mod->arch.got->sh_addr + mod->arch.got->sh_size)); |
1da177e4 LT |
524 | |
525 | e->val = value; | |
526 | ++mod->arch.next_got_entry; | |
527 | found: | |
528 | return (uint64_t) e - mod->arch.gp; | |
529 | } | |
530 | ||
531 | static inline int | |
532 | gp_addressable (struct module *mod, uint64_t value) | |
533 | { | |
534 | return value - mod->arch.gp + MAX_LTOFF/2 < MAX_LTOFF; | |
535 | } | |
536 | ||
537 | /* Get PC-relative PLT entry for this value. Returns 0 on failure. */ | |
538 | static uint64_t | |
539 | get_plt (struct module *mod, const struct insn *insn, uint64_t value, int *okp) | |
540 | { | |
541 | struct plt_entry *plt, *plt_end; | |
542 | uint64_t target_ip, target_gp; | |
543 | ||
544 | if (!*okp) | |
545 | return 0; | |
546 | ||
547 | if (in_init(mod, (uint64_t) insn)) { | |
548 | plt = (void *) mod->arch.init_plt->sh_addr; | |
549 | plt_end = (void *) plt + mod->arch.init_plt->sh_size; | |
550 | } else { | |
551 | plt = (void *) mod->arch.core_plt->sh_addr; | |
552 | plt_end = (void *) plt + mod->arch.core_plt->sh_size; | |
553 | } | |
554 | ||
555 | /* "value" is a pointer to a function-descriptor; fetch the target ip/gp from it: */ | |
556 | target_ip = ((uint64_t *) value)[0]; | |
557 | target_gp = ((uint64_t *) value)[1]; | |
558 | ||
559 | /* Look for existing PLT entry. */ | |
560 | while (plt->bundle[0][0]) { | |
561 | if (plt_target(plt) == target_ip) | |
562 | goto found; | |
563 | if (++plt >= plt_end) | |
564 | BUG(); | |
565 | } | |
566 | *plt = ia64_plt_template; | |
567 | if (!patch_plt(mod, plt, target_ip, target_gp)) { | |
568 | *okp = 0; | |
569 | return 0; | |
570 | } | |
571 | #if ARCH_MODULE_DEBUG | |
572 | if (plt_target(plt) != target_ip) { | |
573 | printk("%s: mistargeted PLT: wanted %lx, got %lx\n", | |
d4ed8084 | 574 | __func__, target_ip, plt_target(plt)); |
1da177e4 LT |
575 | *okp = 0; |
576 | return 0; | |
577 | } | |
578 | #endif | |
579 | found: | |
580 | return (uint64_t) plt; | |
581 | } | |
582 | ||
583 | /* Get function descriptor for VALUE. */ | |
584 | static uint64_t | |
585 | get_fdesc (struct module *mod, uint64_t value, int *okp) | |
586 | { | |
587 | struct fdesc *fdesc = (void *) mod->arch.opd->sh_addr; | |
588 | ||
589 | if (!*okp) | |
590 | return 0; | |
591 | ||
592 | if (!value) { | |
593 | printk(KERN_ERR "%s: fdesc for zero requested!\n", mod->name); | |
594 | return 0; | |
595 | } | |
596 | ||
597 | if (!is_internal(mod, value)) | |
598 | /* | |
599 | * If it's not a module-local entry-point, "value" already points to a | |
600 | * function-descriptor. | |
601 | */ | |
602 | return value; | |
603 | ||
604 | /* Look for existing function descriptor. */ | |
605 | while (fdesc->ip) { | |
606 | if (fdesc->ip == value) | |
607 | return (uint64_t)fdesc; | |
608 | if ((uint64_t) ++fdesc >= mod->arch.opd->sh_addr + mod->arch.opd->sh_size) | |
609 | BUG(); | |
610 | } | |
611 | ||
612 | /* Create new one */ | |
613 | fdesc->ip = value; | |
614 | fdesc->gp = mod->arch.gp; | |
615 | return (uint64_t) fdesc; | |
616 | } | |
617 | ||
618 | static inline int | |
619 | do_reloc (struct module *mod, uint8_t r_type, Elf64_Sym *sym, uint64_t addend, | |
620 | Elf64_Shdr *sec, void *location) | |
621 | { | |
622 | enum reloc_target_format format = (r_type >> FORMAT_SHIFT) & FORMAT_MASK; | |
623 | enum reloc_value_formula formula = (r_type >> VALUE_SHIFT) & VALUE_MASK; | |
624 | uint64_t val; | |
625 | int ok = 1; | |
626 | ||
627 | val = sym->st_value + addend; | |
628 | ||
629 | switch (formula) { | |
630 | case RV_SEGREL: /* segment base is arbitrarily chosen to be 0 for kernel modules */ | |
631 | case RV_DIRECT: | |
632 | break; | |
633 | ||
634 | case RV_GPREL: val -= mod->arch.gp; break; | |
635 | case RV_LTREL: val = get_ltoff(mod, val, &ok); break; | |
636 | case RV_PLTREL: val = get_plt(mod, location, val, &ok); break; | |
637 | case RV_FPTR: val = get_fdesc(mod, val, &ok); break; | |
638 | case RV_SECREL: val -= sec->sh_addr; break; | |
639 | case RV_LTREL_FPTR: val = get_ltoff(mod, get_fdesc(mod, val, &ok), &ok); break; | |
640 | ||
641 | case RV_PCREL: | |
642 | switch (r_type) { | |
643 | case R_IA64_PCREL21B: | |
644 | if ((in_init(mod, val) && in_core(mod, (uint64_t)location)) || | |
645 | (in_core(mod, val) && in_init(mod, (uint64_t)location))) { | |
646 | /* | |
647 | * Init section may have been allocated far away from core, | |
648 | * if the branch won't reach, then allocate a plt for it. | |
649 | */ | |
650 | uint64_t delta = ((int64_t)val - (int64_t)location) / 16; | |
651 | if (delta + (1 << 20) >= (1 << 21)) { | |
652 | val = get_fdesc(mod, val, &ok); | |
653 | val = get_plt(mod, location, val, &ok); | |
654 | } | |
655 | } else if (!is_internal(mod, val)) | |
656 | val = get_plt(mod, location, val, &ok); | |
df561f66 | 657 | fallthrough; |
1da177e4 LT |
658 | default: |
659 | val -= bundle(location); | |
660 | break; | |
661 | ||
662 | case R_IA64_PCREL32MSB: | |
663 | case R_IA64_PCREL32LSB: | |
664 | case R_IA64_PCREL64MSB: | |
665 | case R_IA64_PCREL64LSB: | |
666 | val -= (uint64_t) location; | |
667 | break; | |
668 | ||
669 | } | |
670 | switch (r_type) { | |
671 | case R_IA64_PCREL60B: format = RF_INSN60; break; | |
672 | case R_IA64_PCREL21B: format = RF_INSN21B; break; | |
673 | case R_IA64_PCREL21M: format = RF_INSN21M; break; | |
674 | case R_IA64_PCREL21F: format = RF_INSN21F; break; | |
675 | default: break; | |
676 | } | |
677 | break; | |
678 | ||
679 | case RV_BDREL: | |
7523e4dc | 680 | val -= (uint64_t) (in_init(mod, val) ? mod->init_layout.base : mod->core_layout.base); |
1da177e4 LT |
681 | break; |
682 | ||
683 | case RV_LTV: | |
684 | /* can link-time value relocs happen here? */ | |
685 | BUG(); | |
686 | break; | |
687 | ||
688 | case RV_PCREL2: | |
689 | if (r_type == R_IA64_PCREL21BI) { | |
690 | if (!is_internal(mod, val)) { | |
e088a4ad MW |
691 | printk(KERN_ERR "%s: %s reloc against " |
692 | "non-local symbol (%lx)\n", __func__, | |
693 | reloc_name[r_type], (unsigned long)val); | |
1da177e4 LT |
694 | return -ENOEXEC; |
695 | } | |
696 | format = RF_INSN21B; | |
697 | } | |
698 | val -= bundle(location); | |
699 | break; | |
700 | ||
701 | case RV_SPECIAL: | |
702 | switch (r_type) { | |
703 | case R_IA64_IPLTMSB: | |
704 | case R_IA64_IPLTLSB: | |
705 | val = get_fdesc(mod, get_plt(mod, location, val, &ok), &ok); | |
706 | format = RF_64LSB; | |
707 | if (r_type == R_IA64_IPLTMSB) | |
708 | format = RF_64MSB; | |
709 | break; | |
710 | ||
711 | case R_IA64_SUB: | |
712 | val = addend - sym->st_value; | |
713 | format = RF_INSN64; | |
714 | break; | |
715 | ||
716 | case R_IA64_LTOFF22X: | |
717 | if (gp_addressable(mod, val)) | |
718 | val -= mod->arch.gp; | |
719 | else | |
720 | val = get_ltoff(mod, val, &ok); | |
721 | format = RF_INSN22; | |
722 | break; | |
723 | ||
724 | case R_IA64_LDXMOV: | |
725 | if (gp_addressable(mod, val)) { | |
726 | /* turn "ld8" into "mov": */ | |
d4ed8084 | 727 | DEBUGP("%s: patching ld8 at %p to mov\n", __func__, location); |
1da177e4 LT |
728 | ia64_patch((u64) location, 0x1fff80fe000UL, 0x10000000000UL); |
729 | } | |
730 | return 0; | |
731 | ||
732 | default: | |
733 | if (reloc_name[r_type]) | |
734 | printk(KERN_ERR "%s: special reloc %s not supported", | |
735 | mod->name, reloc_name[r_type]); | |
736 | else | |
737 | printk(KERN_ERR "%s: unknown special reloc %x\n", | |
738 | mod->name, r_type); | |
739 | return -ENOEXEC; | |
740 | } | |
741 | break; | |
742 | ||
743 | case RV_TPREL: | |
744 | case RV_LTREL_TPREL: | |
745 | case RV_DTPMOD: | |
746 | case RV_LTREL_DTPMOD: | |
747 | case RV_DTPREL: | |
748 | case RV_LTREL_DTPREL: | |
749 | printk(KERN_ERR "%s: %s reloc not supported\n", | |
750 | mod->name, reloc_name[r_type] ? reloc_name[r_type] : "?"); | |
751 | return -ENOEXEC; | |
752 | ||
753 | default: | |
754 | printk(KERN_ERR "%s: unknown reloc %x\n", mod->name, r_type); | |
755 | return -ENOEXEC; | |
756 | } | |
757 | ||
758 | if (!ok) | |
759 | return -ENOEXEC; | |
760 | ||
d4ed8084 | 761 | DEBUGP("%s: [%p]<-%016lx = %s(%lx)\n", __func__, location, val, |
1da177e4 LT |
762 | reloc_name[r_type] ? reloc_name[r_type] : "?", sym->st_value + addend); |
763 | ||
764 | switch (format) { | |
765 | case RF_INSN21B: ok = apply_imm21b(mod, location, (int64_t) val / 16); break; | |
766 | case RF_INSN22: ok = apply_imm22(mod, location, val); break; | |
767 | case RF_INSN64: ok = apply_imm64(mod, location, val); break; | |
768 | case RF_INSN60: ok = apply_imm60(mod, location, (int64_t) val / 16); break; | |
769 | case RF_32LSB: put_unaligned(val, (uint32_t *) location); break; | |
770 | case RF_64LSB: put_unaligned(val, (uint64_t *) location); break; | |
771 | case RF_32MSB: /* ia64 Linux is little-endian... */ | |
772 | case RF_64MSB: /* ia64 Linux is little-endian... */ | |
773 | case RF_INSN14: /* must be within-module, i.e., resolved by "ld -r" */ | |
774 | case RF_INSN21M: /* must be within-module, i.e., resolved by "ld -r" */ | |
775 | case RF_INSN21F: /* must be within-module, i.e., resolved by "ld -r" */ | |
776 | printk(KERN_ERR "%s: format %u needed by %s reloc is not supported\n", | |
777 | mod->name, format, reloc_name[r_type] ? reloc_name[r_type] : "?"); | |
778 | return -ENOEXEC; | |
779 | ||
780 | default: | |
781 | printk(KERN_ERR "%s: relocation %s resulted in unknown format %u\n", | |
782 | mod->name, reloc_name[r_type] ? reloc_name[r_type] : "?", format); | |
783 | return -ENOEXEC; | |
784 | } | |
785 | return ok ? 0 : -ENOEXEC; | |
786 | } | |
787 | ||
788 | int | |
789 | apply_relocate_add (Elf64_Shdr *sechdrs, const char *strtab, unsigned int symindex, | |
790 | unsigned int relsec, struct module *mod) | |
791 | { | |
792 | unsigned int i, n = sechdrs[relsec].sh_size / sizeof(Elf64_Rela); | |
793 | Elf64_Rela *rela = (void *) sechdrs[relsec].sh_addr; | |
794 | Elf64_Shdr *target_sec; | |
795 | int ret; | |
796 | ||
d4ed8084 | 797 | DEBUGP("%s: applying section %u (%u relocs) to %u\n", __func__, |
1da177e4 LT |
798 | relsec, n, sechdrs[relsec].sh_info); |
799 | ||
800 | target_sec = sechdrs + sechdrs[relsec].sh_info; | |
801 | ||
802 | if (target_sec->sh_entsize == ~0UL) | |
803 | /* | |
804 | * If target section wasn't allocated, we don't need to relocate it. | |
805 | * Happens, e.g., for debug sections. | |
806 | */ | |
807 | return 0; | |
808 | ||
809 | if (!mod->arch.gp) { | |
810 | /* | |
811 | * XXX Should have an arch-hook for running this after final section | |
812 | * addresses have been selected... | |
813 | */ | |
866ba633 | 814 | uint64_t gp; |
7523e4dc | 815 | if (mod->core_layout.size > MAX_LTOFF) |
1da177e4 LT |
816 | /* |
817 | * This takes advantage of fact that SHF_ARCH_SMALL gets allocated | |
818 | * at the end of the module. | |
819 | */ | |
7523e4dc | 820 | gp = mod->core_layout.size - MAX_LTOFF / 2; |
866ba633 | 821 | else |
7523e4dc RR |
822 | gp = mod->core_layout.size / 2; |
823 | gp = (uint64_t) mod->core_layout.base + ((gp + 7) & -8); | |
1da177e4 | 824 | mod->arch.gp = gp; |
d4ed8084 | 825 | DEBUGP("%s: placing gp at 0x%lx\n", __func__, gp); |
1da177e4 LT |
826 | } |
827 | ||
828 | for (i = 0; i < n; i++) { | |
829 | ret = do_reloc(mod, ELF64_R_TYPE(rela[i].r_info), | |
830 | ((Elf64_Sym *) sechdrs[symindex].sh_addr | |
831 | + ELF64_R_SYM(rela[i].r_info)), | |
832 | rela[i].r_addend, target_sec, | |
833 | (void *) target_sec->sh_addr + rela[i].r_offset); | |
834 | if (ret < 0) | |
835 | return ret; | |
836 | } | |
837 | return 0; | |
838 | } | |
839 | ||
1da177e4 LT |
840 | /* |
841 | * Modules contain a single unwind table which covers both the core and the init text | |
842 | * sections but since the two are not contiguous, we need to split this table up such that | |
72fdbdce | 843 | * we can register (and unregister) each "segment" separately. Fortunately, this sounds |
1da177e4 LT |
844 | * more complicated than it really is. |
845 | */ | |
846 | static void | |
847 | register_unwind_table (struct module *mod) | |
848 | { | |
849 | struct unw_table_entry *start = (void *) mod->arch.unwind->sh_addr; | |
850 | struct unw_table_entry *end = start + mod->arch.unwind->sh_size / sizeof (*start); | |
851 | struct unw_table_entry tmp, *e1, *e2, *core, *init; | |
852 | unsigned long num_init = 0, num_core = 0; | |
853 | ||
854 | /* First, count how many init and core unwind-table entries there are. */ | |
855 | for (e1 = start; e1 < end; ++e1) | |
856 | if (in_init(mod, e1->start_offset)) | |
857 | ++num_init; | |
858 | else | |
859 | ++num_core; | |
860 | /* | |
861 | * Second, sort the table such that all unwind-table entries for the init and core | |
862 | * text sections are nicely separated. We do this with a stupid bubble sort | |
863 | * (unwind tables don't get ridiculously huge). | |
864 | */ | |
865 | for (e1 = start; e1 < end; ++e1) { | |
866 | for (e2 = e1 + 1; e2 < end; ++e2) { | |
867 | if (e2->start_offset < e1->start_offset) { | |
868 | tmp = *e1; | |
869 | *e1 = *e2; | |
870 | *e2 = tmp; | |
871 | } | |
872 | } | |
873 | } | |
874 | /* | |
875 | * Third, locate the init and core segments in the unwind table: | |
876 | */ | |
877 | if (in_init(mod, start->start_offset)) { | |
878 | init = start; | |
879 | core = start + num_init; | |
880 | } else { | |
881 | core = start; | |
882 | init = start + num_core; | |
883 | } | |
884 | ||
d4ed8084 | 885 | DEBUGP("%s: name=%s, gp=%lx, num_init=%lu, num_core=%lu\n", __func__, |
1da177e4 LT |
886 | mod->name, mod->arch.gp, num_init, num_core); |
887 | ||
888 | /* | |
889 | * Fourth, register both tables (if not empty). | |
890 | */ | |
891 | if (num_core > 0) { | |
892 | mod->arch.core_unw_table = unw_add_unwind_table(mod->name, 0, mod->arch.gp, | |
893 | core, core + num_core); | |
d4ed8084 | 894 | DEBUGP("%s: core: handle=%p [%p-%p)\n", __func__, |
1da177e4 LT |
895 | mod->arch.core_unw_table, core, core + num_core); |
896 | } | |
897 | if (num_init > 0) { | |
898 | mod->arch.init_unw_table = unw_add_unwind_table(mod->name, 0, mod->arch.gp, | |
899 | init, init + num_init); | |
d4ed8084 | 900 | DEBUGP("%s: init: handle=%p [%p-%p)\n", __func__, |
1da177e4 LT |
901 | mod->arch.init_unw_table, init, init + num_init); |
902 | } | |
903 | } | |
904 | ||
905 | int | |
906 | module_finalize (const Elf_Ehdr *hdr, const Elf_Shdr *sechdrs, struct module *mod) | |
907 | { | |
d4ed8084 | 908 | DEBUGP("%s: init: entry=%p\n", __func__, mod->init); |
1da177e4 LT |
909 | if (mod->arch.unwind) |
910 | register_unwind_table(mod); | |
911 | return 0; | |
912 | } | |
913 | ||
914 | void | |
915 | module_arch_cleanup (struct module *mod) | |
916 | { | |
c5e5c48c | 917 | if (mod->arch.init_unw_table) { |
1da177e4 | 918 | unw_remove_unwind_table(mod->arch.init_unw_table); |
c5e5c48c | 919 | mod->arch.init_unw_table = NULL; |
920 | } | |
921 | if (mod->arch.core_unw_table) { | |
1da177e4 | 922 | unw_remove_unwind_table(mod->arch.core_unw_table); |
c5e5c48c | 923 | mod->arch.core_unw_table = NULL; |
924 | } | |
1da177e4 | 925 | } |
8e307888 SS |
926 | |
927 | void *dereference_module_function_descriptor(struct module *mod, void *ptr) | |
928 | { | |
929 | Elf64_Shdr *opd = mod->arch.opd; | |
930 | ||
931 | if (ptr < (void *)opd->sh_addr || | |
932 | ptr >= (void *)(opd->sh_addr + opd->sh_size)) | |
933 | return ptr; | |
934 | ||
935 | return dereference_function_descriptor(ptr); | |
936 | } |