1 | /* |
---|
2 | * Taken from NetBSD and stripped of the relocations not needed on RTEMS. |
---|
3 | */ |
---|
4 | |
---|
5 | /* $NetBSD: mdreloc.c,v 1.33 2010/01/14 12:12:07 skrll Exp $ */ |
---|
6 | |
---|
7 | #include <sys/cdefs.h> |
---|
8 | |
---|
9 | #include <errno.h> |
---|
10 | #include <stdio.h> |
---|
11 | #include <string.h> |
---|
12 | #include <sys/types.h> |
---|
13 | #include <sys/stat.h> |
---|
14 | #include <unwind.h> |
---|
15 | #include <unwind-arm-common.h> |
---|
16 | |
---|
17 | #include <rtems/rtl/rtl.h> |
---|
18 | #include "rtl-elf.h" |
---|
19 | #include "rtl-error.h" |
---|
20 | #include <rtems/rtl/rtl-trace.h> |
---|
21 | #include "rtl-unwind.h" |
---|
22 | |
---|
23 | /* |
---|
24 | * It is possible for the compiler to emit relocations for unaligned data. |
---|
25 | * We handle this situation with these inlines. |
---|
26 | */ |
---|
27 | #define RELOC_ALIGNED_P(x) \ |
---|
28 | (((uintptr_t)(x) & (sizeof(void *) - 1)) == 0) |
---|
29 | |
---|
30 | #define SHT_ARM_EXIDX 0x70000001 /* Section holds ARM unwind info. */ |
---|
31 | |
---|
32 | static inline Elf_Addr |
---|
33 | load_ptr(void *where) |
---|
34 | { |
---|
35 | Elf_Addr res; |
---|
36 | |
---|
37 | memcpy(&res, where, sizeof(res)); |
---|
38 | |
---|
39 | return (res); |
---|
40 | } |
---|
41 | |
---|
42 | static inline void |
---|
43 | store_ptr(void *where, Elf_Addr val) |
---|
44 | { |
---|
45 | |
---|
46 | memcpy(where, &val, sizeof(val)); |
---|
47 | } |
---|
48 | |
---|
49 | /* |
---|
50 | * The address of Thumb function symbols is it's real address plus one. |
---|
51 | * This is done by compiler, thus do not consider symtype here. |
---|
52 | */ |
---|
53 | static inline int |
---|
54 | isThumb(Elf_Word symvalue) |
---|
55 | { |
---|
56 | if ((symvalue & 0x1) == 0x1) |
---|
57 | return true; |
---|
58 | else return false; |
---|
59 | } |
---|
60 | |
---|
61 | static inline Elf_SOff |
---|
62 | sign_extend31(Elf_Addr val) |
---|
63 | { |
---|
64 | if (0x40000000 & val) |
---|
65 | val = ~((Elf_Addr)0x7fffffff) | (0x7fffffff & val); |
---|
66 | return 0x7fffffff & val; |
---|
67 | } |
---|
68 | |
---|
69 | uint32_t |
---|
70 | rtems_rtl_elf_section_flags (const rtems_rtl_obj* obj, |
---|
71 | const Elf_Shdr* shdr) |
---|
72 | { |
---|
73 | uint32_t flags = 0; |
---|
74 | if (shdr->sh_type == SHT_ARM_EXIDX) |
---|
75 | flags = RTEMS_RTL_OBJ_SECT_EH | RTEMS_RTL_OBJ_SECT_LOAD; |
---|
76 | return flags; |
---|
77 | } |
---|
78 | |
---|
79 | bool |
---|
80 | rtems_rtl_elf_rel_resolve_sym (Elf_Word type) |
---|
81 | { |
---|
82 | return true; |
---|
83 | } |
---|
84 | |
---|
85 | bool |
---|
86 | rtems_rtl_elf_relocate_rela (const rtems_rtl_obj* obj, |
---|
87 | const Elf_Rela* rela, |
---|
88 | const rtems_rtl_obj_sect* sect, |
---|
89 | const char* symname, |
---|
90 | const Elf_Byte syminfo, |
---|
91 | const Elf_Word symvalue) |
---|
92 | { |
---|
93 | rtems_rtl_set_error (EINVAL, "rela type record not supported"); |
---|
94 | return false; |
---|
95 | } |
---|
96 | |
---|
97 | bool |
---|
98 | rtems_rtl_elf_relocate_rel (const rtems_rtl_obj* obj, |
---|
99 | const Elf_Rel* rel, |
---|
100 | const rtems_rtl_obj_sect* sect, |
---|
101 | const char* symname, |
---|
102 | const Elf_Byte syminfo, |
---|
103 | const Elf_Word symvalue) |
---|
104 | { |
---|
105 | Elf_Addr *where; |
---|
106 | Elf_Addr tmp; |
---|
107 | Elf_Word insn, addend; |
---|
108 | Elf_Word sign, i1, i2; |
---|
109 | uint16_t lower_insn, upper_insn; |
---|
110 | |
---|
111 | where = (Elf_Addr *)(sect->base + rel->r_offset); |
---|
112 | |
---|
113 | switch (ELF_R_TYPE(rel->r_info)) { |
---|
114 | case R_TYPE(NONE): |
---|
115 | if (rtems_rtl_trace (RTEMS_RTL_TRACE_RELOC)) { |
---|
116 | printf ("rtl: NONE %p in %s\n", where, rtems_rtl_obj_oname (obj)); |
---|
117 | } |
---|
118 | break; |
---|
119 | |
---|
120 | case R_TYPE(CALL): /* BL/BLX */ |
---|
121 | case R_TYPE(JUMP24): /* B/BL<cond> */ |
---|
122 | insn = *where; |
---|
123 | |
---|
124 | if (insn & 0x00800000) |
---|
125 | addend = insn | 0xff000000; |
---|
126 | else addend = insn & 0x00ffffff; |
---|
127 | |
---|
128 | if (isThumb(symvalue)) { |
---|
129 | if ((insn & 0xfe000000) == 0xfa000000); /* Already blx */ |
---|
130 | else { |
---|
131 | if ((insn & 0xff000000) == 0xeb000000) { /* BL <label> */ |
---|
132 | *where = (insn & 0x00ffffff) | 0xfa000000; /* BL-->BLX */ |
---|
133 | } else { |
---|
134 | printf("JUMP24 is not suppored from arm to thumb\n"); |
---|
135 | return false; |
---|
136 | } |
---|
137 | } |
---|
138 | } |
---|
139 | |
---|
140 | tmp = symvalue + (addend << 2) - (Elf_Addr)where; |
---|
141 | tmp = (Elf_Sword)tmp >> 2; |
---|
142 | |
---|
143 | if (((Elf_Sword)tmp > 0x7fffff) || ((Elf_Sword)tmp < -0x800000)) { |
---|
144 | printf("CALL/JUMP24 Overflow\n"); |
---|
145 | return false; |
---|
146 | } |
---|
147 | |
---|
148 | *where = (*where & 0xff000000) | (tmp & 0xffffff); |
---|
149 | |
---|
150 | if (rtems_rtl_trace (RTEMS_RTL_TRACE_RELOC)) |
---|
151 | printf ("rtl: JUMP24/PC24/CALL %p @ %p in %s\n", |
---|
152 | (void *)*where, where, rtems_rtl_obj_oname (obj)); |
---|
153 | |
---|
154 | break; |
---|
155 | |
---|
156 | case R_TYPE(V4BX): |
---|
157 | /* Miscellaneous, ignore */ |
---|
158 | if (rtems_rtl_trace (RTEMS_RTL_TRACE_RELOC)) { |
---|
159 | printf ("rtl: V4BX %p @ %p in %s\n", |
---|
160 | (void *)*where, where, rtems_rtl_obj_oname (obj)); |
---|
161 | } |
---|
162 | break; |
---|
163 | |
---|
164 | case R_TYPE(MOVT_ABS): |
---|
165 | case R_TYPE(MOVW_ABS_NC): |
---|
166 | insn = *where; |
---|
167 | |
---|
168 | addend = ((insn >> 4) & 0xf000) | (insn & 0x0fff); |
---|
169 | if (addend & 0x8000) |
---|
170 | addend |= 0xffff0000; |
---|
171 | |
---|
172 | tmp = symvalue + addend; |
---|
173 | |
---|
174 | if (ELF_R_TYPE(rel->r_info) == R_TYPE(MOVW_ABS_NC)) |
---|
175 | tmp &= 0xffff; |
---|
176 | else { |
---|
177 | tmp = (Elf_Sword)tmp >> 16; |
---|
178 | if (((Elf_Sword)tmp > 0x7fff) || ((Elf_Sword)tmp < -0x8000)) { |
---|
179 | printf("MOVT_ABS Overflow\n"); |
---|
180 | return false; |
---|
181 | } |
---|
182 | } |
---|
183 | |
---|
184 | *where = (insn & 0xfff0f000) | ((tmp & 0xf000) << 4) | (tmp & 0xfff); |
---|
185 | |
---|
186 | if (rtems_rtl_trace (RTEMS_RTL_TRACE_RELOC)) |
---|
187 | printf ("rtl: MOVT_ABS/MOVW_ABS_NC %p @ %p in %s\n", |
---|
188 | (void *)*where, where, rtems_rtl_obj_oname (obj)); |
---|
189 | break; |
---|
190 | |
---|
191 | |
---|
192 | case R_TYPE(REL32): /* word32 (S + A) | T - P */ |
---|
193 | case R_TYPE(ABS32): /* word32 (S + A) | T */ |
---|
194 | case R_TYPE(GLOB_DAT): /* word32 (S + A) | T */ |
---|
195 | case R_TYPE(PREL31): /* word32 (S + A) | T - P */ |
---|
196 | case R_TYPE(TARGET2): /* Equivalent to REL32 */ |
---|
197 | if (__predict_true(RELOC_ALIGNED_P(where))) { |
---|
198 | tmp = *where + symvalue; |
---|
199 | if (isThumb(symvalue)) |
---|
200 | tmp |= 1; |
---|
201 | if (ELF_R_TYPE(rel->r_info) == R_TYPE(REL32) || |
---|
202 | ELF_R_TYPE(rel->r_info) == R_TYPE(TARGET2)) |
---|
203 | tmp -= (Elf_Addr)where; |
---|
204 | else if (ELF_R_TYPE(rel->r_info) == R_TYPE(PREL31)) |
---|
205 | tmp = sign_extend31(tmp - (Elf_Addr)where); |
---|
206 | *where = tmp; |
---|
207 | } else { |
---|
208 | tmp = load_ptr(where) + symvalue; |
---|
209 | if (isThumb(symvalue)) |
---|
210 | tmp |= 1; |
---|
211 | if (ELF_R_TYPE(rel->r_info) == R_TYPE(REL32) || |
---|
212 | ELF_R_TYPE(rel->r_info) == R_TYPE(TARGET2)) |
---|
213 | tmp -= (Elf_Addr)where; |
---|
214 | else if (ELF_R_TYPE(rel->r_info) == R_TYPE(PREL31)) |
---|
215 | tmp = sign_extend31(tmp - (Elf_Addr)where); |
---|
216 | store_ptr(where, tmp); |
---|
217 | } |
---|
218 | |
---|
219 | if (rtems_rtl_trace (RTEMS_RTL_TRACE_RELOC)) |
---|
220 | printf ("rtl: REL32/ABS32/GLOB_DAT/PREL31/TARGET2 %p @ %p in %s\n", |
---|
221 | (void *)tmp, where, rtems_rtl_obj_oname (obj)); |
---|
222 | break; |
---|
223 | |
---|
224 | case R_TYPE(THM_MOVT_ABS): |
---|
225 | case R_TYPE(THM_MOVW_ABS_NC): |
---|
226 | upper_insn = *(uint16_t *)where; |
---|
227 | lower_insn = *((uint16_t *)where + 1); |
---|
228 | |
---|
229 | addend = ((upper_insn & 0x000f) << 12) | ((upper_insn & 0x0400) << 1) | |
---|
230 | ((lower_insn & 0x7000) >> 4) | (lower_insn & 0x00ff); |
---|
231 | addend = (addend ^ 0x8000) - 0x8000; |
---|
232 | |
---|
233 | tmp = addend + symvalue; |
---|
234 | if (ELF32_R_TYPE(rel->r_info) == R_ARM_THM_MOVT_ABS) |
---|
235 | tmp >>= 16; |
---|
236 | |
---|
237 | *(uint16_t *)where = (uint16_t)((upper_insn & 0xfbf0) | |
---|
238 | ((tmp & 0xf000) >> 12) | |
---|
239 | ((tmp & 0x0800) >> 1)); |
---|
240 | *((uint16_t *)where + 1) = (uint16_t)((lower_insn & 0x8f00) | |
---|
241 | ((tmp & 0x0700) << 4) | |
---|
242 | (tmp & 0x00ff)); |
---|
243 | |
---|
244 | if (rtems_rtl_trace (RTEMS_RTL_TRACE_RELOC)) { |
---|
245 | printf ("rtl: THM_MOVT_ABS/THM_MOVW_ABS_NC %p @ %p in %s\n", |
---|
246 | (void *)*where, where, rtems_rtl_obj_oname (obj)); |
---|
247 | } |
---|
248 | |
---|
249 | break; |
---|
250 | |
---|
251 | case R_TYPE(THM_JUMP24): |
---|
252 | /* same to THM_CALL; insn b.w */ |
---|
253 | case R_TYPE(THM_CALL): |
---|
254 | upper_insn = *(uint16_t *)where; |
---|
255 | lower_insn = *((uint16_t *)where + 1); |
---|
256 | sign = (upper_insn & (1 << 10)) >> 10; |
---|
257 | i1 = ((lower_insn >> 13) & 1) ^ sign ? 0 : 1; |
---|
258 | i2 = ((lower_insn >> 11) & 1) ^ sign ? 0 : 1; |
---|
259 | tmp = (i1 << 23) | (i2 << 22) | ((upper_insn & 0x3ff) << 12) | ((lower_insn & 0x7ff) << 1); |
---|
260 | addend = (tmp | ((sign ? 0 : 1) << 24)) - (1 << 24); |
---|
261 | |
---|
262 | if (isThumb(symvalue)) ;/*Thumb to Thumb call, nothing to care */ |
---|
263 | else { |
---|
264 | if (ELF_R_TYPE(rel->r_info) == R_TYPE(THM_JUMP24)) { |
---|
265 | tmp = (tmp + 2) & ~3; /* aligned to 4 bytes only for JUMP24 */ |
---|
266 | printf("THM_JUMP24 to arm not supported\n"); |
---|
267 | return false; |
---|
268 | } |
---|
269 | else { |
---|
270 | /* THM_CALL bl-->blx */ |
---|
271 | lower_insn &=~(1<<12); |
---|
272 | } |
---|
273 | } |
---|
274 | |
---|
275 | tmp = symvalue + addend; |
---|
276 | tmp = tmp - (Elf_Addr)where; |
---|
277 | |
---|
278 | if (((Elf_Sword)tmp > 0x7fffff) || ((Elf_Sword)tmp < -0x800000)) { |
---|
279 | printf("THM_CALL/JUMP24 overflow\n"); |
---|
280 | return false; |
---|
281 | } |
---|
282 | |
---|
283 | sign = (tmp >> 24) & 1; |
---|
284 | *(uint16_t *)where = (uint16_t)((upper_insn & 0xf800) | (sign << 10) | |
---|
285 | ((tmp >> 12) & 0x3ff)); |
---|
286 | |
---|
287 | *((uint16_t *)where + 1) = (uint16_t)((lower_insn & 0xd000)| |
---|
288 | ((sign ^ (~(tmp >> 23) & 1)) << 13) | |
---|
289 | ((sign ^ (~(tmp >> 22) & 1)) << 11) | |
---|
290 | ((tmp >> 1) & 0x7ff)); |
---|
291 | |
---|
292 | if (rtems_rtl_trace (RTEMS_RTL_TRACE_RELOC)){ |
---|
293 | printf ("rtl: THM_CALL/JUMP24 %p @ %p in %s\n", |
---|
294 | (void *)*where, where, rtems_rtl_obj_oname (obj)); |
---|
295 | } |
---|
296 | |
---|
297 | break; |
---|
298 | |
---|
299 | case R_TYPE(THM_JUMP19): |
---|
300 | |
---|
301 | if (!isThumb(symvalue)) { |
---|
302 | printf("THM_JUMP19 to arm not supported\n"); |
---|
303 | return false; |
---|
304 | } |
---|
305 | |
---|
306 | upper_insn = *(uint16_t *)where; |
---|
307 | lower_insn = *((uint16_t *)where + 1); |
---|
308 | sign = (upper_insn >> 10) & 0x1; |
---|
309 | |
---|
310 | if ((((upper_insn & 0x3f) >> 7) & 0x7) == 0x7) { |
---|
311 | printf("THM_JUMP19 failed\n"); |
---|
312 | return false; /*if cond <3:1> == '111', see Related codings in armv7a manual */ |
---|
313 | } |
---|
314 | |
---|
315 | i1 = (lower_insn >> 13) & 0x1; |
---|
316 | i2 = (lower_insn >> 11) & 0x1; |
---|
317 | |
---|
318 | tmp = ((i2 << 19) | (i1 << 18) | ((upper_insn & 0x3f) << 12) | ((lower_insn & 0x7ff) << 1)); |
---|
319 | addend = (tmp | ((sign ? 0 : 1) << 20)) - (1 << 20); |
---|
320 | tmp = symvalue + addend; |
---|
321 | |
---|
322 | tmp = tmp - (Elf_Addr)where; |
---|
323 | |
---|
324 | if (((Elf_Sword)tmp > 0x7ffffe) || ((Elf_Sword)tmp < -0x800000)) { |
---|
325 | rtems_rtl_set_error (EINVAL, "%s: Overflow %ld " |
---|
326 | "THM_JUMP19 relocations", |
---|
327 | sect->name, (uint32_t) ELF_R_TYPE(rel->r_info)); |
---|
328 | return false; |
---|
329 | } |
---|
330 | |
---|
331 | sign = (tmp >> 20) & 0x1; |
---|
332 | i2 = (tmp >> 19) & 0x1; |
---|
333 | i1 = (tmp >> 18) & 0x1; |
---|
334 | |
---|
335 | *(uint16_t*)where = (upper_insn & 0xfbc0) | (sign << 10) | ((tmp >> 12) & 0x3f); |
---|
336 | *((uint16_t*)where + 1) = (lower_insn & 0xd000) | (i1 << 13) | |
---|
337 | (i2 << 11) | ((tmp >> 1) & 0x7ff); |
---|
338 | |
---|
339 | if (rtems_rtl_trace (RTEMS_RTL_TRACE_RELOC)) |
---|
340 | printf ("rtl: THM_JUMP19 %p @ %p in %s\n", |
---|
341 | (void *)*where, where, rtems_rtl_obj_oname (obj)); |
---|
342 | break; |
---|
343 | |
---|
344 | default: |
---|
345 | printf ("rtl: reloc unknown: sym = %lu, type = %lu, offset = %p, " |
---|
346 | "contents = %p\n", |
---|
347 | ELF_R_SYM(rel->r_info), (uint32_t) ELF_R_TYPE(rel->r_info), |
---|
348 | (void *)rel->r_offset, (void *)*where); |
---|
349 | rtems_rtl_set_error (EINVAL, |
---|
350 | "%s: Unsupported relocation type %ld " |
---|
351 | "in non-PLT relocations", |
---|
352 | sect->name, (uint32_t) ELF_R_TYPE(rel->r_info)); |
---|
353 | return false; |
---|
354 | } |
---|
355 | |
---|
356 | return true; |
---|
357 | } |
---|
358 | |
---|
359 | bool |
---|
360 | rtems_rtl_elf_unwind_parse (const rtems_rtl_obj* obj, |
---|
361 | const char* name, |
---|
362 | uint32_t flags) |
---|
363 | { |
---|
364 | /* |
---|
365 | * We location the EH sections in section flags. |
---|
366 | */ |
---|
367 | return false; |
---|
368 | } |
---|
369 | |
---|
370 | bool |
---|
371 | rtems_rtl_elf_unwind_register (rtems_rtl_obj* obj) |
---|
372 | { |
---|
373 | return true; |
---|
374 | } |
---|
375 | |
---|
376 | bool |
---|
377 | rtems_rtl_elf_unwind_deregister (rtems_rtl_obj* obj) |
---|
378 | { |
---|
379 | obj->loader = NULL; |
---|
380 | return true; |
---|
381 | } |
---|
382 | |
---|
383 | /* An exception index table entry. */ |
---|
384 | typedef struct __EIT_entry |
---|
385 | { |
---|
386 | _uw fnoffset; |
---|
387 | _uw content; |
---|
388 | } __EIT_entry; |
---|
389 | |
---|
390 | /* The exception index table location in the base module */ |
---|
391 | extern __EIT_entry __exidx_start; |
---|
392 | extern __EIT_entry __exidx_end; |
---|
393 | |
---|
394 | /* |
---|
395 | * A weak reference is in libgcc, provide a real version and provide a way to |
---|
396 | * manage loaded modules. |
---|
397 | * |
---|
398 | * Passed in the return address and a reference to the number of records |
---|
399 | * found. We set the start of the exidx data and the number of records. |
---|
400 | */ |
---|
401 | _Unwind_Ptr __gnu_Unwind_Find_exidx (_Unwind_Ptr return_address, |
---|
402 | int* nrec) __attribute__ ((__noinline__, |
---|
403 | __used__, |
---|
404 | __noclone__)); |
---|
405 | |
---|
406 | _Unwind_Ptr __gnu_Unwind_Find_exidx (_Unwind_Ptr return_address, |
---|
407 | int* nrec) |
---|
408 | { |
---|
409 | rtems_rtl_data* rtl; |
---|
410 | rtems_chain_node* node; |
---|
411 | __EIT_entry* exidx_start = &__exidx_start; |
---|
412 | __EIT_entry* exidx_end = &__exidx_end; |
---|
413 | |
---|
414 | rtl = rtems_rtl_lock (); |
---|
415 | |
---|
416 | node = rtems_chain_first (&rtl->objects); |
---|
417 | while (!rtems_chain_is_tail (&rtl->objects, node)) { |
---|
418 | rtems_rtl_obj* obj = (rtems_rtl_obj*) node; |
---|
419 | if (rtems_rtl_obj_text_inside (obj, (void*) return_address)) { |
---|
420 | exidx_start = (__EIT_entry*) obj->eh_base; |
---|
421 | exidx_end = (__EIT_entry*) (obj->eh_base + obj->eh_size); |
---|
422 | break; |
---|
423 | } |
---|
424 | node = rtems_chain_next (node); |
---|
425 | } |
---|
426 | |
---|
427 | rtems_rtl_unlock (); |
---|
428 | |
---|
429 | *nrec = exidx_end - exidx_start; |
---|
430 | |
---|
431 | return (_Unwind_Ptr) exidx_start; |
---|
432 | } |
---|