glue(bswap_ehdr,SZ)1 static void glue(bswap_ehdr, SZ)(struct elfhdr *ehdr)
2 {
3 bswap16s(&ehdr->e_type); /* Object file type */
4 bswap16s(&ehdr->e_machine); /* Architecture */
5 bswap32s(&ehdr->e_version); /* Object file version */
6 bswapSZs(&ehdr->e_entry); /* Entry point virtual address */
7 bswapSZs(&ehdr->e_phoff); /* Program header table file offset */
8 bswapSZs(&ehdr->e_shoff); /* Section header table file offset */
9 bswap32s(&ehdr->e_flags); /* Processor-specific flags */
10 bswap16s(&ehdr->e_ehsize); /* ELF header size in bytes */
11 bswap16s(&ehdr->e_phentsize); /* Program header table entry size */
12 bswap16s(&ehdr->e_phnum); /* Program header table entry count */
13 bswap16s(&ehdr->e_shentsize); /* Section header table entry size */
14 bswap16s(&ehdr->e_shnum); /* Section header table entry count */
15 bswap16s(&ehdr->e_shstrndx); /* Section header string table index */
16 }
17
glue(bswap_phdr,SZ)18 static void glue(bswap_phdr, SZ)(struct elf_phdr *phdr)
19 {
20 bswap32s(&phdr->p_type); /* Segment type */
21 bswapSZs(&phdr->p_offset); /* Segment file offset */
22 bswapSZs(&phdr->p_vaddr); /* Segment virtual address */
23 bswapSZs(&phdr->p_paddr); /* Segment physical address */
24 bswapSZs(&phdr->p_filesz); /* Segment size in file */
25 bswapSZs(&phdr->p_memsz); /* Segment size in memory */
26 bswap32s(&phdr->p_flags); /* Segment flags */
27 bswapSZs(&phdr->p_align); /* Segment alignment */
28 }
29
glue(bswap_shdr,SZ)30 static void glue(bswap_shdr, SZ)(struct elf_shdr *shdr)
31 {
32 bswap32s(&shdr->sh_name);
33 bswap32s(&shdr->sh_type);
34 bswapSZs(&shdr->sh_flags);
35 bswapSZs(&shdr->sh_addr);
36 bswapSZs(&shdr->sh_offset);
37 bswapSZs(&shdr->sh_size);
38 bswap32s(&shdr->sh_link);
39 bswap32s(&shdr->sh_info);
40 bswapSZs(&shdr->sh_addralign);
41 bswapSZs(&shdr->sh_entsize);
42 }
43
glue(bswap_sym,SZ)44 static void glue(bswap_sym, SZ)(struct elf_sym *sym)
45 {
46 bswap32s(&sym->st_name);
47 bswapSZs(&sym->st_value);
48 bswapSZs(&sym->st_size);
49 bswap16s(&sym->st_shndx);
50 }
51
glue(bswap_rela,SZ)52 static void glue(bswap_rela, SZ)(struct elf_rela *rela)
53 {
54 bswapSZs(&rela->r_offset);
55 bswapSZs(&rela->r_info);
56 bswapSZs((elf_word *)&rela->r_addend);
57 }
58
glue(find_section,SZ)59 static struct elf_shdr *glue(find_section, SZ)(struct elf_shdr *shdr_table,
60 int n, int type)
61 {
62 int i;
63 for(i=0;i<n;i++) {
64 if (shdr_table[i].sh_type == type)
65 return shdr_table + i;
66 }
67 return NULL;
68 }
69
glue(symfind,SZ)70 static int glue(symfind, SZ)(const void *s0, const void *s1)
71 {
72 hwaddr addr = *(hwaddr *)s0;
73 struct elf_sym *sym = (struct elf_sym *)s1;
74 int result = 0;
75 if (addr < sym->st_value) {
76 result = -1;
77 } else if (addr >= sym->st_value + sym->st_size) {
78 result = 1;
79 }
80 return result;
81 }
82
glue(lookup_symbol,SZ)83 static const char *glue(lookup_symbol, SZ)(struct syminfo *s,
84 hwaddr orig_addr)
85 {
86 struct elf_sym *syms = glue(s->disas_symtab.elf, SZ);
87 struct elf_sym *sym;
88
89 sym = bsearch(&orig_addr, syms, s->disas_num_syms, sizeof(*syms),
90 glue(symfind, SZ));
91 if (sym != NULL) {
92 return s->disas_strtab + sym->st_name;
93 }
94
95 return "";
96 }
97
glue(symcmp,SZ)98 static int glue(symcmp, SZ)(const void *s0, const void *s1)
99 {
100 struct elf_sym *sym0 = (struct elf_sym *)s0;
101 struct elf_sym *sym1 = (struct elf_sym *)s1;
102 return (sym0->st_value < sym1->st_value)
103 ? -1
104 : ((sym0->st_value > sym1->st_value) ? 1 : 0);
105 }
106
glue(load_symbols,SZ)107 static int glue(load_symbols, SZ)(struct elfhdr *ehdr, int fd, int must_swab,
108 int clear_lsb, symbol_fn_t sym_cb)
109 {
110 struct elf_shdr *symtab, *strtab, *shdr_table = NULL;
111 struct elf_sym *syms = NULL;
112 struct syminfo *s;
113 int nsyms, i;
114 char *str = NULL;
115
116 shdr_table = load_at(fd, ehdr->e_shoff,
117 sizeof(struct elf_shdr) * ehdr->e_shnum);
118 if (!shdr_table)
119 return -1;
120
121 if (must_swab) {
122 for (i = 0; i < ehdr->e_shnum; i++) {
123 glue(bswap_shdr, SZ)(shdr_table + i);
124 }
125 }
126
127 symtab = glue(find_section, SZ)(shdr_table, ehdr->e_shnum, SHT_SYMTAB);
128 if (!symtab)
129 goto fail;
130 syms = load_at(fd, symtab->sh_offset, symtab->sh_size);
131 if (!syms)
132 goto fail;
133
134 nsyms = symtab->sh_size / sizeof(struct elf_sym);
135
136 /* String table */
137 if (symtab->sh_link >= ehdr->e_shnum) {
138 goto fail;
139 }
140 strtab = &shdr_table[symtab->sh_link];
141
142 str = load_at(fd, strtab->sh_offset, strtab->sh_size);
143 if (!str) {
144 goto fail;
145 }
146
147 i = 0;
148 while (i < nsyms) {
149 if (must_swab) {
150 glue(bswap_sym, SZ)(&syms[i]);
151 }
152 if (sym_cb) {
153 sym_cb(str + syms[i].st_name, syms[i].st_info,
154 syms[i].st_value, syms[i].st_size);
155 }
156 /* We are only interested in function symbols.
157 Throw everything else away. */
158 if (syms[i].st_shndx == SHN_UNDEF ||
159 syms[i].st_shndx >= SHN_LORESERVE ||
160 ELF_ST_TYPE(syms[i].st_info) != STT_FUNC) {
161 nsyms--;
162 if (i < nsyms) {
163 syms[i] = syms[nsyms];
164 }
165 continue;
166 }
167 if (clear_lsb) {
168 /* The bottom address bit marks a Thumb or MIPS16 symbol. */
169 syms[i].st_value &= ~(glue(glue(Elf, SZ), _Addr))1;
170 }
171 i++;
172 }
173 syms = g_realloc(syms, nsyms * sizeof(*syms));
174
175 qsort(syms, nsyms, sizeof(*syms), glue(symcmp, SZ));
176 for (i = 0; i < nsyms - 1; i++) {
177 if (syms[i].st_size == 0) {
178 syms[i].st_size = syms[i + 1].st_value - syms[i].st_value;
179 }
180 }
181
182 /* Commit */
183 s = g_malloc0(sizeof(*s));
184 s->lookup_symbol = glue(lookup_symbol, SZ);
185 glue(s->disas_symtab.elf, SZ) = syms;
186 s->disas_num_syms = nsyms;
187 s->disas_strtab = str;
188 s->next = syminfos;
189 syminfos = s;
190 g_free(shdr_table);
191 return 0;
192 fail:
193 g_free(syms);
194 g_free(str);
195 g_free(shdr_table);
196 return -1;
197 }
198
glue(elf_reloc,SZ)199 static int glue(elf_reloc, SZ)(struct elfhdr *ehdr, int fd, int must_swab,
200 uint64_t (*translate_fn)(void *, uint64_t),
201 void *translate_opaque, uint8_t *data,
202 struct elf_phdr *ph, int elf_machine)
203 {
204 struct elf_shdr *reltab, *shdr_table = NULL;
205 struct elf_rela *rels = NULL;
206 int nrels, i, ret = -1;
207 elf_word wordval;
208 void *addr;
209
210 shdr_table = load_at(fd, ehdr->e_shoff,
211 sizeof(struct elf_shdr) * ehdr->e_shnum);
212 if (!shdr_table) {
213 return -1;
214 }
215 if (must_swab) {
216 for (i = 0; i < ehdr->e_shnum; i++) {
217 glue(bswap_shdr, SZ)(&shdr_table[i]);
218 }
219 }
220
221 reltab = glue(find_section, SZ)(shdr_table, ehdr->e_shnum, SHT_RELA);
222 if (!reltab) {
223 goto fail;
224 }
225 rels = load_at(fd, reltab->sh_offset, reltab->sh_size);
226 if (!rels) {
227 goto fail;
228 }
229 nrels = reltab->sh_size / sizeof(struct elf_rela);
230
231 for (i = 0; i < nrels; i++) {
232 if (must_swab) {
233 glue(bswap_rela, SZ)(&rels[i]);
234 }
235 if (rels[i].r_offset < ph->p_vaddr ||
236 rels[i].r_offset >= ph->p_vaddr + ph->p_filesz) {
237 continue;
238 }
239 addr = &data[rels[i].r_offset - ph->p_vaddr];
240 switch (elf_machine) {
241 case EM_S390:
242 switch (rels[i].r_info) {
243 case R_390_RELATIVE:
244 wordval = *(elf_word *)addr;
245 if (must_swab) {
246 bswapSZs(&wordval);
247 }
248 wordval = translate_fn(translate_opaque, wordval);
249 if (must_swab) {
250 bswapSZs(&wordval);
251 }
252 *(elf_word *)addr = wordval;
253 break;
254 default:
255 fprintf(stderr, "Unsupported relocation type %i!\n",
256 (int)rels[i].r_info);
257 }
258 }
259 }
260
261 ret = 0;
262 fail:
263 g_free(rels);
264 g_free(shdr_table);
265 return ret;
266 }
267
268 /*
269 * Given 'nhdr', a pointer to a range of ELF Notes, search through them
270 * for a note matching type 'elf_note_type' and return a pointer to
271 * the matching ELF note.
272 */
glue(get_elf_note_type,SZ)273 static struct elf_note *glue(get_elf_note_type, SZ)(struct elf_note *nhdr,
274 elf_word note_size,
275 elf_word phdr_align,
276 elf_word elf_note_type)
277 {
278 elf_word nhdr_size = sizeof(struct elf_note);
279 elf_word elf_note_entry_offset = 0;
280 elf_word note_type;
281 elf_word nhdr_namesz;
282 elf_word nhdr_descsz;
283
284 if (nhdr == NULL) {
285 return NULL;
286 }
287
288 note_type = nhdr->n_type;
289 while (note_type != elf_note_type) {
290 nhdr_namesz = nhdr->n_namesz;
291 nhdr_descsz = nhdr->n_descsz;
292
293 elf_note_entry_offset = nhdr_size +
294 QEMU_ALIGN_UP(nhdr_namesz, phdr_align) +
295 QEMU_ALIGN_UP(nhdr_descsz, phdr_align);
296
297 /*
298 * If the offset calculated in this iteration exceeds the
299 * supplied size, we are done and no matching note was found.
300 */
301 if (elf_note_entry_offset > note_size) {
302 return NULL;
303 }
304
305 /* skip to the next ELF Note entry */
306 nhdr = (void *)nhdr + elf_note_entry_offset;
307 note_type = nhdr->n_type;
308 }
309
310 return nhdr;
311 }
312
glue(load_elf,SZ)313 static int glue(load_elf, SZ)(const char *name, int fd,
314 uint64_t (*elf_note_fn)(void *, void *, bool),
315 uint64_t (*translate_fn)(void *, uint64_t),
316 void *translate_opaque,
317 int must_swab, uint64_t *pentry,
318 uint64_t *lowaddr, uint64_t *highaddr,
319 int elf_machine, int clear_lsb, int data_swab,
320 AddressSpace *as, bool load_rom,
321 symbol_fn_t sym_cb)
322 {
323 struct elfhdr ehdr;
324 struct elf_phdr *phdr = NULL, *ph;
325 int size, i, total_size;
326 elf_word mem_size, file_size, data_offset;
327 uint64_t addr, low = (uint64_t)-1, high = 0;
328 GMappedFile *mapped_file = NULL;
329 uint8_t *data = NULL;
330 char label[128];
331 int ret = ELF_LOAD_FAILED;
332
333 if (read(fd, &ehdr, sizeof(ehdr)) != sizeof(ehdr))
334 goto fail;
335 if (must_swab) {
336 glue(bswap_ehdr, SZ)(&ehdr);
337 }
338
339 if (elf_machine <= EM_NONE) {
340 /* The caller didn't specify an ARCH, we can figure it out */
341 elf_machine = ehdr.e_machine;
342 }
343
344 switch (elf_machine) {
345 case EM_PPC64:
346 if (ehdr.e_machine != EM_PPC64) {
347 if (ehdr.e_machine != EM_PPC) {
348 ret = ELF_LOAD_WRONG_ARCH;
349 goto fail;
350 }
351 }
352 break;
353 case EM_X86_64:
354 if (ehdr.e_machine != EM_X86_64) {
355 if (ehdr.e_machine != EM_386) {
356 ret = ELF_LOAD_WRONG_ARCH;
357 goto fail;
358 }
359 }
360 break;
361 case EM_MICROBLAZE:
362 if (ehdr.e_machine != EM_MICROBLAZE) {
363 if (ehdr.e_machine != EM_MICROBLAZE_OLD) {
364 ret = ELF_LOAD_WRONG_ARCH;
365 goto fail;
366 }
367 }
368 break;
369 case EM_MOXIE:
370 if (ehdr.e_machine != EM_MOXIE) {
371 if (ehdr.e_machine != EM_MOXIE_OLD) {
372 ret = ELF_LOAD_WRONG_ARCH;
373 goto fail;
374 }
375 }
376 break;
377 case EM_MIPS:
378 case EM_NANOMIPS:
379 if ((ehdr.e_machine != EM_MIPS) &&
380 (ehdr.e_machine != EM_NANOMIPS)) {
381 ret = ELF_LOAD_WRONG_ARCH;
382 goto fail;
383 }
384 break;
385 default:
386 if (elf_machine != ehdr.e_machine) {
387 ret = ELF_LOAD_WRONG_ARCH;
388 goto fail;
389 }
390 }
391
392 if (pentry)
393 *pentry = (uint64_t)(elf_sword)ehdr.e_entry;
394
395 glue(load_symbols, SZ)(&ehdr, fd, must_swab, clear_lsb, sym_cb);
396
397 size = ehdr.e_phnum * sizeof(phdr[0]);
398 if (lseek(fd, ehdr.e_phoff, SEEK_SET) != ehdr.e_phoff) {
399 goto fail;
400 }
401 phdr = g_malloc0(size);
402 if (!phdr)
403 goto fail;
404 if (read(fd, phdr, size) != size)
405 goto fail;
406 if (must_swab) {
407 for(i = 0; i < ehdr.e_phnum; i++) {
408 ph = &phdr[i];
409 glue(bswap_phdr, SZ)(ph);
410 }
411 }
412
413 /*
414 * Since we want to be able to modify the mapped buffer, we set the
415 * 'writeble' parameter to 'true'. Modifications to the buffer are not
416 * written back to the file.
417 */
418 mapped_file = g_mapped_file_new_from_fd(fd, true, NULL);
419 if (!mapped_file) {
420 goto fail;
421 }
422
423 total_size = 0;
424 for(i = 0; i < ehdr.e_phnum; i++) {
425 ph = &phdr[i];
426 if (ph->p_type == PT_LOAD) {
427 mem_size = ph->p_memsz; /* Size of the ROM */
428 file_size = ph->p_filesz; /* Size of the allocated data */
429 data_offset = ph->p_offset; /* Offset where the data is located */
430
431 if (file_size > 0) {
432 if (g_mapped_file_get_length(mapped_file) <
433 file_size + data_offset) {
434 goto fail;
435 }
436
437 data = (uint8_t *)g_mapped_file_get_contents(mapped_file);
438 data += data_offset;
439 }
440
441 /* The ELF spec is somewhat vague about the purpose of the
442 * physical address field. One common use in the embedded world
443 * is that physical address field specifies the load address
444 * and the virtual address field specifies the execution address.
445 * Segments are packed into ROM or flash, and the relocation
446 * and zero-initialization of data is done at runtime. This
447 * means that the memsz header represents the runtime size of the
448 * segment, but the filesz represents the loadtime size. If
449 * we try to honour the memsz value for an ELF file like this
450 * we will end up with overlapping segments (which the
451 * loader.c code will later reject).
452 * We support ELF files using this scheme by by checking whether
453 * paddr + memsz for this segment would overlap with any other
454 * segment. If so, then we assume it's using this scheme and
455 * truncate the loaded segment to the filesz size.
456 * If the segment considered as being memsz size doesn't overlap
457 * then we use memsz for the segment length, to handle ELF files
458 * which assume that the loader will do the zero-initialization.
459 */
460 if (mem_size > file_size) {
461 /* If this segment's zero-init portion overlaps another
462 * segment's data or zero-init portion, then truncate this one.
463 * Invalid ELF files where the segments overlap even when
464 * only file_size bytes are loaded will be rejected by
465 * the ROM overlap check in loader.c, so we don't try to
466 * explicitly detect those here.
467 */
468 int j;
469 elf_word zero_start = ph->p_paddr + file_size;
470 elf_word zero_end = ph->p_paddr + mem_size;
471
472 for (j = 0; j < ehdr.e_phnum; j++) {
473 struct elf_phdr *jph = &phdr[j];
474
475 if (i != j && jph->p_type == PT_LOAD) {
476 elf_word other_start = jph->p_paddr;
477 elf_word other_end = jph->p_paddr + jph->p_memsz;
478
479 if (!(other_start >= zero_end ||
480 zero_start >= other_end)) {
481 mem_size = file_size;
482 break;
483 }
484 }
485 }
486 }
487
488 if (mem_size > INT_MAX - total_size) {
489 ret = ELF_LOAD_TOO_BIG;
490 goto fail;
491 }
492
493 /* address_offset is hack for kernel images that are
494 linked at the wrong physical address. */
495 if (translate_fn) {
496 addr = translate_fn(translate_opaque, ph->p_paddr);
497 glue(elf_reloc, SZ)(&ehdr, fd, must_swab, translate_fn,
498 translate_opaque, data, ph, elf_machine);
499 } else {
500 addr = ph->p_paddr;
501 }
502
503 if (data_swab) {
504 int j;
505 for (j = 0; j < file_size; j += (1 << data_swab)) {
506 uint8_t *dp = data + j;
507 switch (data_swab) {
508 case (1):
509 *(uint16_t *)dp = bswap16(*(uint16_t *)dp);
510 break;
511 case (2):
512 *(uint32_t *)dp = bswap32(*(uint32_t *)dp);
513 break;
514 case (3):
515 *(uint64_t *)dp = bswap64(*(uint64_t *)dp);
516 break;
517 default:
518 g_assert_not_reached();
519 }
520 }
521 }
522
523 /* the entry pointer in the ELF header is a virtual
524 * address, if the text segments paddr and vaddr differ
525 * we need to adjust the entry */
526 if (pentry && !translate_fn &&
527 ph->p_vaddr != ph->p_paddr &&
528 ehdr.e_entry >= ph->p_vaddr &&
529 ehdr.e_entry < ph->p_vaddr + ph->p_filesz &&
530 ph->p_flags & PF_X) {
531 *pentry = ehdr.e_entry - ph->p_vaddr + ph->p_paddr;
532 }
533
534 /* Some ELF files really do have segments of zero size;
535 * just ignore them rather than trying to create empty
536 * ROM blobs, because the zero-length blob can falsely
537 * trigger the overlapping-ROM-blobs check.
538 */
539 if (mem_size != 0) {
540 if (load_rom) {
541 snprintf(label, sizeof(label), "phdr #%d: %s", i, name);
542
543 /*
544 * rom_add_elf_program() takes its own reference to
545 * 'mapped_file'.
546 */
547 rom_add_elf_program(label, mapped_file, data, file_size,
548 mem_size, addr, as);
549 } else {
550 address_space_write(as ? as : &address_space_memory,
551 addr, MEMTXATTRS_UNSPECIFIED,
552 data, file_size);
553 }
554 }
555
556 total_size += mem_size;
557 if (addr < low)
558 low = addr;
559 if ((addr + mem_size) > high)
560 high = addr + mem_size;
561
562 data = NULL;
563
564 } else if (ph->p_type == PT_NOTE && elf_note_fn) {
565 struct elf_note *nhdr = NULL;
566
567 file_size = ph->p_filesz; /* Size of the range of ELF notes */
568 data_offset = ph->p_offset; /* Offset where the notes are located */
569
570 if (file_size > 0) {
571 if (g_mapped_file_get_length(mapped_file) <
572 file_size + data_offset) {
573 goto fail;
574 }
575
576 data = (uint8_t *)g_mapped_file_get_contents(mapped_file);
577 data += data_offset;
578 }
579
580 /*
581 * Search the ELF notes to find one with a type matching the
582 * value passed in via 'translate_opaque'
583 */
584 nhdr = (struct elf_note *)data;
585 assert(translate_opaque != NULL);
586 nhdr = glue(get_elf_note_type, SZ)(nhdr, file_size, ph->p_align,
587 *(uint64_t *)translate_opaque);
588 if (nhdr != NULL) {
589 bool is64 =
590 sizeof(struct elf_note) == sizeof(struct elf64_note);
591 elf_note_fn((void *)nhdr, (void *)&ph->p_align, is64);
592 }
593 data = NULL;
594 }
595 }
596
597 if (lowaddr)
598 *lowaddr = (uint64_t)(elf_sword)low;
599 if (highaddr)
600 *highaddr = (uint64_t)(elf_sword)high;
601 ret = total_size;
602 fail:
603 g_mapped_file_unref(mapped_file);
604 g_free(phdr);
605 return ret;
606 }
607