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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 | ||
1da177e4 | 307 | void |
d453cded | 308 | module_arch_freeing_init (struct module *mod) |
1da177e4 | 309 | { |
d453cded | 310 | if (mod->arch.init_unw_table) { |
1da177e4 LT |
311 | unw_remove_unwind_table(mod->arch.init_unw_table); |
312 | mod->arch.init_unw_table = NULL; | |
313 | } | |
1da177e4 LT |
314 | } |
315 | ||
316 | /* Have we already seen one of these relocations? */ | |
317 | /* FIXME: we could look in other sections, too --RR */ | |
318 | static int | |
319 | duplicate_reloc (const Elf64_Rela *rela, unsigned int num) | |
320 | { | |
321 | unsigned int i; | |
322 | ||
323 | for (i = 0; i < num; i++) { | |
324 | if (rela[i].r_info == rela[num].r_info && rela[i].r_addend == rela[num].r_addend) | |
325 | return 1; | |
326 | } | |
327 | return 0; | |
328 | } | |
329 | ||
330 | /* Count how many GOT entries we may need */ | |
331 | static unsigned int | |
332 | count_gots (const Elf64_Rela *rela, unsigned int num) | |
333 | { | |
334 | unsigned int i, ret = 0; | |
335 | ||
336 | /* Sure, this is order(n^2), but it's usually short, and not | |
337 | time critical */ | |
338 | for (i = 0; i < num; i++) { | |
339 | switch (ELF64_R_TYPE(rela[i].r_info)) { | |
340 | case R_IA64_LTOFF22: | |
341 | case R_IA64_LTOFF22X: | |
342 | case R_IA64_LTOFF64I: | |
343 | case R_IA64_LTOFF_FPTR22: | |
344 | case R_IA64_LTOFF_FPTR64I: | |
345 | case R_IA64_LTOFF_FPTR32MSB: | |
346 | case R_IA64_LTOFF_FPTR32LSB: | |
347 | case R_IA64_LTOFF_FPTR64MSB: | |
348 | case R_IA64_LTOFF_FPTR64LSB: | |
349 | if (!duplicate_reloc(rela, i)) | |
350 | ret++; | |
351 | break; | |
352 | } | |
353 | } | |
354 | return ret; | |
355 | } | |
356 | ||
357 | /* Count how many PLT entries we may need */ | |
358 | static unsigned int | |
359 | count_plts (const Elf64_Rela *rela, unsigned int num) | |
360 | { | |
361 | unsigned int i, ret = 0; | |
362 | ||
363 | /* Sure, this is order(n^2), but it's usually short, and not | |
364 | time critical */ | |
365 | for (i = 0; i < num; i++) { | |
366 | switch (ELF64_R_TYPE(rela[i].r_info)) { | |
367 | case R_IA64_PCREL21B: | |
368 | case R_IA64_PLTOFF22: | |
369 | case R_IA64_PLTOFF64I: | |
370 | case R_IA64_PLTOFF64MSB: | |
371 | case R_IA64_PLTOFF64LSB: | |
372 | case R_IA64_IPLTMSB: | |
373 | case R_IA64_IPLTLSB: | |
374 | if (!duplicate_reloc(rela, i)) | |
375 | ret++; | |
376 | break; | |
377 | } | |
378 | } | |
379 | return ret; | |
380 | } | |
381 | ||
382 | /* We need to create an function-descriptors for any internal function | |
383 | which is referenced. */ | |
384 | static unsigned int | |
385 | count_fdescs (const Elf64_Rela *rela, unsigned int num) | |
386 | { | |
387 | unsigned int i, ret = 0; | |
388 | ||
389 | /* Sure, this is order(n^2), but it's usually short, and not time critical. */ | |
390 | for (i = 0; i < num; i++) { | |
391 | switch (ELF64_R_TYPE(rela[i].r_info)) { | |
392 | case R_IA64_FPTR64I: | |
393 | case R_IA64_FPTR32LSB: | |
394 | case R_IA64_FPTR32MSB: | |
395 | case R_IA64_FPTR64LSB: | |
396 | case R_IA64_FPTR64MSB: | |
397 | case R_IA64_LTOFF_FPTR22: | |
398 | case R_IA64_LTOFF_FPTR32LSB: | |
399 | case R_IA64_LTOFF_FPTR32MSB: | |
400 | case R_IA64_LTOFF_FPTR64I: | |
401 | case R_IA64_LTOFF_FPTR64LSB: | |
402 | case R_IA64_LTOFF_FPTR64MSB: | |
403 | case R_IA64_IPLTMSB: | |
404 | case R_IA64_IPLTLSB: | |
405 | /* | |
406 | * Jumps to static functions sometimes go straight to their | |
407 | * offset. Of course, that may not be possible if the jump is | |
408 | * from init -> core or vice. versa, so we need to generate an | |
409 | * FDESC (and PLT etc) for that. | |
410 | */ | |
411 | case R_IA64_PCREL21B: | |
412 | if (!duplicate_reloc(rela, i)) | |
413 | ret++; | |
414 | break; | |
415 | } | |
416 | } | |
417 | return ret; | |
418 | } | |
419 | ||
420 | int | |
421 | module_frob_arch_sections (Elf_Ehdr *ehdr, Elf_Shdr *sechdrs, char *secstrings, | |
422 | struct module *mod) | |
423 | { | |
424 | unsigned long core_plts = 0, init_plts = 0, gots = 0, fdescs = 0; | |
425 | Elf64_Shdr *s, *sechdrs_end = sechdrs + ehdr->e_shnum; | |
426 | ||
427 | /* | |
428 | * To store the PLTs and function-descriptors, we expand the .text section for | |
429 | * core module-code and the .init.text section for initialization code. | |
430 | */ | |
431 | for (s = sechdrs; s < sechdrs_end; ++s) | |
432 | if (strcmp(".core.plt", secstrings + s->sh_name) == 0) | |
433 | mod->arch.core_plt = s; | |
434 | else if (strcmp(".init.plt", secstrings + s->sh_name) == 0) | |
435 | mod->arch.init_plt = s; | |
436 | else if (strcmp(".got", secstrings + s->sh_name) == 0) | |
437 | mod->arch.got = s; | |
438 | else if (strcmp(".opd", secstrings + s->sh_name) == 0) | |
439 | mod->arch.opd = s; | |
440 | else if (strcmp(".IA_64.unwind", secstrings + s->sh_name) == 0) | |
441 | mod->arch.unwind = s; | |
442 | ||
443 | if (!mod->arch.core_plt || !mod->arch.init_plt || !mod->arch.got || !mod->arch.opd) { | |
444 | printk(KERN_ERR "%s: sections missing\n", mod->name); | |
445 | return -ENOEXEC; | |
446 | } | |
447 | ||
448 | /* GOT and PLTs can occur in any relocated section... */ | |
449 | for (s = sechdrs + 1; s < sechdrs_end; ++s) { | |
450 | const Elf64_Rela *rels = (void *)ehdr + s->sh_offset; | |
451 | unsigned long numrels = s->sh_size/sizeof(Elf64_Rela); | |
452 | ||
453 | if (s->sh_type != SHT_RELA) | |
454 | continue; | |
455 | ||
456 | gots += count_gots(rels, numrels); | |
457 | fdescs += count_fdescs(rels, numrels); | |
458 | if (strstr(secstrings + s->sh_name, ".init")) | |
459 | init_plts += count_plts(rels, numrels); | |
460 | else | |
461 | core_plts += count_plts(rels, numrels); | |
462 | } | |
463 | ||
464 | mod->arch.core_plt->sh_type = SHT_NOBITS; | |
465 | mod->arch.core_plt->sh_flags = SHF_EXECINSTR | SHF_ALLOC; | |
466 | mod->arch.core_plt->sh_addralign = 16; | |
467 | mod->arch.core_plt->sh_size = core_plts * sizeof(struct plt_entry); | |
468 | mod->arch.init_plt->sh_type = SHT_NOBITS; | |
469 | mod->arch.init_plt->sh_flags = SHF_EXECINSTR | SHF_ALLOC; | |
470 | mod->arch.init_plt->sh_addralign = 16; | |
471 | mod->arch.init_plt->sh_size = init_plts * sizeof(struct plt_entry); | |
472 | mod->arch.got->sh_type = SHT_NOBITS; | |
473 | mod->arch.got->sh_flags = ARCH_SHF_SMALL | SHF_ALLOC; | |
474 | mod->arch.got->sh_addralign = 8; | |
475 | mod->arch.got->sh_size = gots * sizeof(struct got_entry); | |
476 | mod->arch.opd->sh_type = SHT_NOBITS; | |
477 | mod->arch.opd->sh_flags = SHF_ALLOC; | |
478 | mod->arch.opd->sh_addralign = 8; | |
479 | mod->arch.opd->sh_size = fdescs * sizeof(struct fdesc); | |
480 | DEBUGP("%s: core.plt=%lx, init.plt=%lx, got=%lx, fdesc=%lx\n", | |
d4ed8084 | 481 | __func__, mod->arch.core_plt->sh_size, mod->arch.init_plt->sh_size, |
1da177e4 LT |
482 | mod->arch.got->sh_size, mod->arch.opd->sh_size); |
483 | return 0; | |
484 | } | |
485 | ||
486 | static inline int | |
487 | in_init (const struct module *mod, uint64_t addr) | |
488 | { | |
7523e4dc | 489 | return addr - (uint64_t) mod->init_layout.base < mod->init_layout.size; |
1da177e4 LT |
490 | } |
491 | ||
492 | static inline int | |
493 | in_core (const struct module *mod, uint64_t addr) | |
494 | { | |
7523e4dc | 495 | return addr - (uint64_t) mod->core_layout.base < mod->core_layout.size; |
1da177e4 LT |
496 | } |
497 | ||
498 | static inline int | |
499 | is_internal (const struct module *mod, uint64_t value) | |
500 | { | |
501 | return in_init(mod, value) || in_core(mod, value); | |
502 | } | |
503 | ||
504 | /* | |
505 | * Get gp-relative offset for the linkage-table entry of VALUE. | |
506 | */ | |
507 | static uint64_t | |
508 | get_ltoff (struct module *mod, uint64_t value, int *okp) | |
509 | { | |
510 | struct got_entry *got, *e; | |
511 | ||
512 | if (!*okp) | |
513 | return 0; | |
514 | ||
515 | got = (void *) mod->arch.got->sh_addr; | |
516 | for (e = got; e < got + mod->arch.next_got_entry; ++e) | |
517 | if (e->val == value) | |
518 | goto found; | |
519 | ||
520 | /* Not enough GOT entries? */ | |
80a03e29 | 521 | BUG_ON(e >= (struct got_entry *) (mod->arch.got->sh_addr + mod->arch.got->sh_size)); |
1da177e4 LT |
522 | |
523 | e->val = value; | |
524 | ++mod->arch.next_got_entry; | |
525 | found: | |
526 | return (uint64_t) e - mod->arch.gp; | |
527 | } | |
528 | ||
529 | static inline int | |
530 | gp_addressable (struct module *mod, uint64_t value) | |
531 | { | |
532 | return value - mod->arch.gp + MAX_LTOFF/2 < MAX_LTOFF; | |
533 | } | |
534 | ||
535 | /* Get PC-relative PLT entry for this value. Returns 0 on failure. */ | |
536 | static uint64_t | |
537 | get_plt (struct module *mod, const struct insn *insn, uint64_t value, int *okp) | |
538 | { | |
539 | struct plt_entry *plt, *plt_end; | |
540 | uint64_t target_ip, target_gp; | |
541 | ||
542 | if (!*okp) | |
543 | return 0; | |
544 | ||
545 | if (in_init(mod, (uint64_t) insn)) { | |
546 | plt = (void *) mod->arch.init_plt->sh_addr; | |
547 | plt_end = (void *) plt + mod->arch.init_plt->sh_size; | |
548 | } else { | |
549 | plt = (void *) mod->arch.core_plt->sh_addr; | |
550 | plt_end = (void *) plt + mod->arch.core_plt->sh_size; | |
551 | } | |
552 | ||
553 | /* "value" is a pointer to a function-descriptor; fetch the target ip/gp from it: */ | |
554 | target_ip = ((uint64_t *) value)[0]; | |
555 | target_gp = ((uint64_t *) value)[1]; | |
556 | ||
557 | /* Look for existing PLT entry. */ | |
558 | while (plt->bundle[0][0]) { | |
559 | if (plt_target(plt) == target_ip) | |
560 | goto found; | |
561 | if (++plt >= plt_end) | |
562 | BUG(); | |
563 | } | |
564 | *plt = ia64_plt_template; | |
565 | if (!patch_plt(mod, plt, target_ip, target_gp)) { | |
566 | *okp = 0; | |
567 | return 0; | |
568 | } | |
569 | #if ARCH_MODULE_DEBUG | |
570 | if (plt_target(plt) != target_ip) { | |
571 | printk("%s: mistargeted PLT: wanted %lx, got %lx\n", | |
d4ed8084 | 572 | __func__, target_ip, plt_target(plt)); |
1da177e4 LT |
573 | *okp = 0; |
574 | return 0; | |
575 | } | |
576 | #endif | |
577 | found: | |
578 | return (uint64_t) plt; | |
579 | } | |
580 | ||
581 | /* Get function descriptor for VALUE. */ | |
582 | static uint64_t | |
583 | get_fdesc (struct module *mod, uint64_t value, int *okp) | |
584 | { | |
585 | struct fdesc *fdesc = (void *) mod->arch.opd->sh_addr; | |
586 | ||
587 | if (!*okp) | |
588 | return 0; | |
589 | ||
590 | if (!value) { | |
591 | printk(KERN_ERR "%s: fdesc for zero requested!\n", mod->name); | |
592 | return 0; | |
593 | } | |
594 | ||
595 | if (!is_internal(mod, value)) | |
596 | /* | |
597 | * If it's not a module-local entry-point, "value" already points to a | |
598 | * function-descriptor. | |
599 | */ | |
600 | return value; | |
601 | ||
602 | /* Look for existing function descriptor. */ | |
603 | while (fdesc->ip) { | |
604 | if (fdesc->ip == value) | |
605 | return (uint64_t)fdesc; | |
606 | if ((uint64_t) ++fdesc >= mod->arch.opd->sh_addr + mod->arch.opd->sh_size) | |
607 | BUG(); | |
608 | } | |
609 | ||
610 | /* Create new one */ | |
611 | fdesc->ip = value; | |
612 | fdesc->gp = mod->arch.gp; | |
613 | return (uint64_t) fdesc; | |
614 | } | |
615 | ||
616 | static inline int | |
617 | do_reloc (struct module *mod, uint8_t r_type, Elf64_Sym *sym, uint64_t addend, | |
618 | Elf64_Shdr *sec, void *location) | |
619 | { | |
620 | enum reloc_target_format format = (r_type >> FORMAT_SHIFT) & FORMAT_MASK; | |
621 | enum reloc_value_formula formula = (r_type >> VALUE_SHIFT) & VALUE_MASK; | |
622 | uint64_t val; | |
623 | int ok = 1; | |
624 | ||
625 | val = sym->st_value + addend; | |
626 | ||
627 | switch (formula) { | |
628 | case RV_SEGREL: /* segment base is arbitrarily chosen to be 0 for kernel modules */ | |
629 | case RV_DIRECT: | |
630 | break; | |
631 | ||
632 | case RV_GPREL: val -= mod->arch.gp; break; | |
633 | case RV_LTREL: val = get_ltoff(mod, val, &ok); break; | |
634 | case RV_PLTREL: val = get_plt(mod, location, val, &ok); break; | |
635 | case RV_FPTR: val = get_fdesc(mod, val, &ok); break; | |
636 | case RV_SECREL: val -= sec->sh_addr; break; | |
637 | case RV_LTREL_FPTR: val = get_ltoff(mod, get_fdesc(mod, val, &ok), &ok); break; | |
638 | ||
639 | case RV_PCREL: | |
640 | switch (r_type) { | |
641 | case R_IA64_PCREL21B: | |
642 | if ((in_init(mod, val) && in_core(mod, (uint64_t)location)) || | |
643 | (in_core(mod, val) && in_init(mod, (uint64_t)location))) { | |
644 | /* | |
645 | * Init section may have been allocated far away from core, | |
646 | * if the branch won't reach, then allocate a plt for it. | |
647 | */ | |
648 | uint64_t delta = ((int64_t)val - (int64_t)location) / 16; | |
649 | if (delta + (1 << 20) >= (1 << 21)) { | |
650 | val = get_fdesc(mod, val, &ok); | |
651 | val = get_plt(mod, location, val, &ok); | |
652 | } | |
653 | } else if (!is_internal(mod, val)) | |
654 | val = get_plt(mod, location, val, &ok); | |
655 | /* FALL THROUGH */ | |
656 | default: | |
657 | val -= bundle(location); | |
658 | break; | |
659 | ||
660 | case R_IA64_PCREL32MSB: | |
661 | case R_IA64_PCREL32LSB: | |
662 | case R_IA64_PCREL64MSB: | |
663 | case R_IA64_PCREL64LSB: | |
664 | val -= (uint64_t) location; | |
665 | break; | |
666 | ||
667 | } | |
668 | switch (r_type) { | |
669 | case R_IA64_PCREL60B: format = RF_INSN60; break; | |
670 | case R_IA64_PCREL21B: format = RF_INSN21B; break; | |
671 | case R_IA64_PCREL21M: format = RF_INSN21M; break; | |
672 | case R_IA64_PCREL21F: format = RF_INSN21F; break; | |
673 | default: break; | |
674 | } | |
675 | break; | |
676 | ||
677 | case RV_BDREL: | |
7523e4dc | 678 | val -= (uint64_t) (in_init(mod, val) ? mod->init_layout.base : mod->core_layout.base); |
1da177e4 LT |
679 | break; |
680 | ||
681 | case RV_LTV: | |
682 | /* can link-time value relocs happen here? */ | |
683 | BUG(); | |
684 | break; | |
685 | ||
686 | case RV_PCREL2: | |
687 | if (r_type == R_IA64_PCREL21BI) { | |
688 | if (!is_internal(mod, val)) { | |
e088a4ad MW |
689 | printk(KERN_ERR "%s: %s reloc against " |
690 | "non-local symbol (%lx)\n", __func__, | |
691 | reloc_name[r_type], (unsigned long)val); | |
1da177e4 LT |
692 | return -ENOEXEC; |
693 | } | |
694 | format = RF_INSN21B; | |
695 | } | |
696 | val -= bundle(location); | |
697 | break; | |
698 | ||
699 | case RV_SPECIAL: | |
700 | switch (r_type) { | |
701 | case R_IA64_IPLTMSB: | |
702 | case R_IA64_IPLTLSB: | |
703 | val = get_fdesc(mod, get_plt(mod, location, val, &ok), &ok); | |
704 | format = RF_64LSB; | |
705 | if (r_type == R_IA64_IPLTMSB) | |
706 | format = RF_64MSB; | |
707 | break; | |
708 | ||
709 | case R_IA64_SUB: | |
710 | val = addend - sym->st_value; | |
711 | format = RF_INSN64; | |
712 | break; | |
713 | ||
714 | case R_IA64_LTOFF22X: | |
715 | if (gp_addressable(mod, val)) | |
716 | val -= mod->arch.gp; | |
717 | else | |
718 | val = get_ltoff(mod, val, &ok); | |
719 | format = RF_INSN22; | |
720 | break; | |
721 | ||
722 | case R_IA64_LDXMOV: | |
723 | if (gp_addressable(mod, val)) { | |
724 | /* turn "ld8" into "mov": */ | |
d4ed8084 | 725 | DEBUGP("%s: patching ld8 at %p to mov\n", __func__, location); |
1da177e4 LT |
726 | ia64_patch((u64) location, 0x1fff80fe000UL, 0x10000000000UL); |
727 | } | |
728 | return 0; | |
729 | ||
730 | default: | |
731 | if (reloc_name[r_type]) | |
732 | printk(KERN_ERR "%s: special reloc %s not supported", | |
733 | mod->name, reloc_name[r_type]); | |
734 | else | |
735 | printk(KERN_ERR "%s: unknown special reloc %x\n", | |
736 | mod->name, r_type); | |
737 | return -ENOEXEC; | |
738 | } | |
739 | break; | |
740 | ||
741 | case RV_TPREL: | |
742 | case RV_LTREL_TPREL: | |
743 | case RV_DTPMOD: | |
744 | case RV_LTREL_DTPMOD: | |
745 | case RV_DTPREL: | |
746 | case RV_LTREL_DTPREL: | |
747 | printk(KERN_ERR "%s: %s reloc not supported\n", | |
748 | mod->name, reloc_name[r_type] ? reloc_name[r_type] : "?"); | |
749 | return -ENOEXEC; | |
750 | ||
751 | default: | |
752 | printk(KERN_ERR "%s: unknown reloc %x\n", mod->name, r_type); | |
753 | return -ENOEXEC; | |
754 | } | |
755 | ||
756 | if (!ok) | |
757 | return -ENOEXEC; | |
758 | ||
d4ed8084 | 759 | DEBUGP("%s: [%p]<-%016lx = %s(%lx)\n", __func__, location, val, |
1da177e4 LT |
760 | reloc_name[r_type] ? reloc_name[r_type] : "?", sym->st_value + addend); |
761 | ||
762 | switch (format) { | |
763 | case RF_INSN21B: ok = apply_imm21b(mod, location, (int64_t) val / 16); break; | |
764 | case RF_INSN22: ok = apply_imm22(mod, location, val); break; | |
765 | case RF_INSN64: ok = apply_imm64(mod, location, val); break; | |
766 | case RF_INSN60: ok = apply_imm60(mod, location, (int64_t) val / 16); break; | |
767 | case RF_32LSB: put_unaligned(val, (uint32_t *) location); break; | |
768 | case RF_64LSB: put_unaligned(val, (uint64_t *) location); break; | |
769 | case RF_32MSB: /* ia64 Linux is little-endian... */ | |
770 | case RF_64MSB: /* ia64 Linux is little-endian... */ | |
771 | case RF_INSN14: /* must be within-module, i.e., resolved by "ld -r" */ | |
772 | case RF_INSN21M: /* must be within-module, i.e., resolved by "ld -r" */ | |
773 | case RF_INSN21F: /* must be within-module, i.e., resolved by "ld -r" */ | |
774 | printk(KERN_ERR "%s: format %u needed by %s reloc is not supported\n", | |
775 | mod->name, format, reloc_name[r_type] ? reloc_name[r_type] : "?"); | |
776 | return -ENOEXEC; | |
777 | ||
778 | default: | |
779 | printk(KERN_ERR "%s: relocation %s resulted in unknown format %u\n", | |
780 | mod->name, reloc_name[r_type] ? reloc_name[r_type] : "?", format); | |
781 | return -ENOEXEC; | |
782 | } | |
783 | return ok ? 0 : -ENOEXEC; | |
784 | } | |
785 | ||
786 | int | |
787 | apply_relocate_add (Elf64_Shdr *sechdrs, const char *strtab, unsigned int symindex, | |
788 | unsigned int relsec, struct module *mod) | |
789 | { | |
790 | unsigned int i, n = sechdrs[relsec].sh_size / sizeof(Elf64_Rela); | |
791 | Elf64_Rela *rela = (void *) sechdrs[relsec].sh_addr; | |
792 | Elf64_Shdr *target_sec; | |
793 | int ret; | |
794 | ||
d4ed8084 | 795 | DEBUGP("%s: applying section %u (%u relocs) to %u\n", __func__, |
1da177e4 LT |
796 | relsec, n, sechdrs[relsec].sh_info); |
797 | ||
798 | target_sec = sechdrs + sechdrs[relsec].sh_info; | |
799 | ||
800 | if (target_sec->sh_entsize == ~0UL) | |
801 | /* | |
802 | * If target section wasn't allocated, we don't need to relocate it. | |
803 | * Happens, e.g., for debug sections. | |
804 | */ | |
805 | return 0; | |
806 | ||
807 | if (!mod->arch.gp) { | |
808 | /* | |
809 | * XXX Should have an arch-hook for running this after final section | |
810 | * addresses have been selected... | |
811 | */ | |
866ba633 | 812 | uint64_t gp; |
7523e4dc | 813 | if (mod->core_layout.size > MAX_LTOFF) |
1da177e4 LT |
814 | /* |
815 | * This takes advantage of fact that SHF_ARCH_SMALL gets allocated | |
816 | * at the end of the module. | |
817 | */ | |
7523e4dc | 818 | gp = mod->core_layout.size - MAX_LTOFF / 2; |
866ba633 | 819 | else |
7523e4dc RR |
820 | gp = mod->core_layout.size / 2; |
821 | gp = (uint64_t) mod->core_layout.base + ((gp + 7) & -8); | |
1da177e4 | 822 | mod->arch.gp = gp; |
d4ed8084 | 823 | DEBUGP("%s: placing gp at 0x%lx\n", __func__, gp); |
1da177e4 LT |
824 | } |
825 | ||
826 | for (i = 0; i < n; i++) { | |
827 | ret = do_reloc(mod, ELF64_R_TYPE(rela[i].r_info), | |
828 | ((Elf64_Sym *) sechdrs[symindex].sh_addr | |
829 | + ELF64_R_SYM(rela[i].r_info)), | |
830 | rela[i].r_addend, target_sec, | |
831 | (void *) target_sec->sh_addr + rela[i].r_offset); | |
832 | if (ret < 0) | |
833 | return ret; | |
834 | } | |
835 | return 0; | |
836 | } | |
837 | ||
1da177e4 LT |
838 | /* |
839 | * Modules contain a single unwind table which covers both the core and the init text | |
840 | * sections but since the two are not contiguous, we need to split this table up such that | |
72fdbdce | 841 | * we can register (and unregister) each "segment" separately. Fortunately, this sounds |
1da177e4 LT |
842 | * more complicated than it really is. |
843 | */ | |
844 | static void | |
845 | register_unwind_table (struct module *mod) | |
846 | { | |
847 | struct unw_table_entry *start = (void *) mod->arch.unwind->sh_addr; | |
848 | struct unw_table_entry *end = start + mod->arch.unwind->sh_size / sizeof (*start); | |
849 | struct unw_table_entry tmp, *e1, *e2, *core, *init; | |
850 | unsigned long num_init = 0, num_core = 0; | |
851 | ||
852 | /* First, count how many init and core unwind-table entries there are. */ | |
853 | for (e1 = start; e1 < end; ++e1) | |
854 | if (in_init(mod, e1->start_offset)) | |
855 | ++num_init; | |
856 | else | |
857 | ++num_core; | |
858 | /* | |
859 | * Second, sort the table such that all unwind-table entries for the init and core | |
860 | * text sections are nicely separated. We do this with a stupid bubble sort | |
861 | * (unwind tables don't get ridiculously huge). | |
862 | */ | |
863 | for (e1 = start; e1 < end; ++e1) { | |
864 | for (e2 = e1 + 1; e2 < end; ++e2) { | |
865 | if (e2->start_offset < e1->start_offset) { | |
866 | tmp = *e1; | |
867 | *e1 = *e2; | |
868 | *e2 = tmp; | |
869 | } | |
870 | } | |
871 | } | |
872 | /* | |
873 | * Third, locate the init and core segments in the unwind table: | |
874 | */ | |
875 | if (in_init(mod, start->start_offset)) { | |
876 | init = start; | |
877 | core = start + num_init; | |
878 | } else { | |
879 | core = start; | |
880 | init = start + num_core; | |
881 | } | |
882 | ||
d4ed8084 | 883 | DEBUGP("%s: name=%s, gp=%lx, num_init=%lu, num_core=%lu\n", __func__, |
1da177e4 LT |
884 | mod->name, mod->arch.gp, num_init, num_core); |
885 | ||
886 | /* | |
887 | * Fourth, register both tables (if not empty). | |
888 | */ | |
889 | if (num_core > 0) { | |
890 | mod->arch.core_unw_table = unw_add_unwind_table(mod->name, 0, mod->arch.gp, | |
891 | core, core + num_core); | |
d4ed8084 | 892 | DEBUGP("%s: core: handle=%p [%p-%p)\n", __func__, |
1da177e4 LT |
893 | mod->arch.core_unw_table, core, core + num_core); |
894 | } | |
895 | if (num_init > 0) { | |
896 | mod->arch.init_unw_table = unw_add_unwind_table(mod->name, 0, mod->arch.gp, | |
897 | init, init + num_init); | |
d4ed8084 | 898 | DEBUGP("%s: init: handle=%p [%p-%p)\n", __func__, |
1da177e4 LT |
899 | mod->arch.init_unw_table, init, init + num_init); |
900 | } | |
901 | } | |
902 | ||
903 | int | |
904 | module_finalize (const Elf_Ehdr *hdr, const Elf_Shdr *sechdrs, struct module *mod) | |
905 | { | |
d4ed8084 | 906 | DEBUGP("%s: init: entry=%p\n", __func__, mod->init); |
1da177e4 LT |
907 | if (mod->arch.unwind) |
908 | register_unwind_table(mod); | |
909 | return 0; | |
910 | } | |
911 | ||
912 | void | |
913 | module_arch_cleanup (struct module *mod) | |
914 | { | |
915 | if (mod->arch.init_unw_table) | |
916 | unw_remove_unwind_table(mod->arch.init_unw_table); | |
917 | if (mod->arch.core_unw_table) | |
918 | unw_remove_unwind_table(mod->arch.core_unw_table); | |
919 | } |