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1 | /* | |
2 | * ELF loading code | |
3 | * | |
4 | * Copyright (c) 2013 Stacey D. Son | |
5 | * | |
6 | * This program is free software; you can redistribute it and/or modify | |
7 | * it under the terms of the GNU General Public License as published by | |
8 | * the Free Software Foundation; either version 2 of the License, or | |
9 | * (at your option) any later version. | |
10 | * | |
11 | * This program is distributed in the hope that it will be useful, | |
12 | * but WITHOUT ANY WARRANTY; without even the implied warranty of | |
13 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | |
14 | * GNU General Public License for more details. | |
15 | * | |
16 | * You should have received a copy of the GNU General Public License | |
17 | * along with this program; if not, see <http://www.gnu.org/licenses/>. | |
18 | */ | |
19 | ||
20 | #include "qemu/osdep.h" | |
21 | ||
22 | #include "qemu.h" | |
23 | #include "disas/disas.h" | |
24 | #include "qemu/path.h" | |
25 | ||
26 | static abi_ulong target_auxents; /* Where the AUX entries are in target */ | |
27 | static size_t target_auxents_sz; /* Size of AUX entries including AT_NULL */ | |
28 | ||
29 | #include "target_os_elf.h" | |
30 | #include "target_os_stack.h" | |
31 | #include "target_os_thread.h" | |
32 | ||
33 | #include "elf.h" | |
34 | ||
35 | abi_ulong target_stksiz; | |
36 | abi_ulong target_stkbas; | |
37 | ||
38 | static inline void memcpy_fromfs(void *to, const void *from, unsigned long n) | |
39 | { | |
40 | memcpy(to, from, n); | |
41 | } | |
42 | ||
43 | #ifdef BSWAP_NEEDED | |
44 | static void bswap_ehdr(struct elfhdr *ehdr) | |
45 | { | |
46 | bswap16s(&ehdr->e_type); /* Object file type */ | |
47 | bswap16s(&ehdr->e_machine); /* Architecture */ | |
48 | bswap32s(&ehdr->e_version); /* Object file version */ | |
49 | bswaptls(&ehdr->e_entry); /* Entry point virtual address */ | |
50 | bswaptls(&ehdr->e_phoff); /* Program header table file offset */ | |
51 | bswaptls(&ehdr->e_shoff); /* Section header table file offset */ | |
52 | bswap32s(&ehdr->e_flags); /* Processor-specific flags */ | |
53 | bswap16s(&ehdr->e_ehsize); /* ELF header size in bytes */ | |
54 | bswap16s(&ehdr->e_phentsize); /* Program header table entry size */ | |
55 | bswap16s(&ehdr->e_phnum); /* Program header table entry count */ | |
56 | bswap16s(&ehdr->e_shentsize); /* Section header table entry size */ | |
57 | bswap16s(&ehdr->e_shnum); /* Section header table entry count */ | |
58 | bswap16s(&ehdr->e_shstrndx); /* Section header string table index */ | |
59 | } | |
60 | ||
61 | static void bswap_phdr(struct elf_phdr *phdr, int phnum) | |
62 | { | |
63 | int i; | |
64 | ||
65 | for (i = 0; i < phnum; i++, phdr++) { | |
66 | bswap32s(&phdr->p_type); /* Segment type */ | |
67 | bswap32s(&phdr->p_flags); /* Segment flags */ | |
68 | bswaptls(&phdr->p_offset); /* Segment file offset */ | |
69 | bswaptls(&phdr->p_vaddr); /* Segment virtual address */ | |
70 | bswaptls(&phdr->p_paddr); /* Segment physical address */ | |
71 | bswaptls(&phdr->p_filesz); /* Segment size in file */ | |
72 | bswaptls(&phdr->p_memsz); /* Segment size in memory */ | |
73 | bswaptls(&phdr->p_align); /* Segment alignment */ | |
74 | } | |
75 | } | |
76 | ||
77 | static void bswap_shdr(struct elf_shdr *shdr, int shnum) | |
78 | { | |
79 | int i; | |
80 | ||
81 | for (i = 0; i < shnum; i++, shdr++) { | |
82 | bswap32s(&shdr->sh_name); | |
83 | bswap32s(&shdr->sh_type); | |
84 | bswaptls(&shdr->sh_flags); | |
85 | bswaptls(&shdr->sh_addr); | |
86 | bswaptls(&shdr->sh_offset); | |
87 | bswaptls(&shdr->sh_size); | |
88 | bswap32s(&shdr->sh_link); | |
89 | bswap32s(&shdr->sh_info); | |
90 | bswaptls(&shdr->sh_addralign); | |
91 | bswaptls(&shdr->sh_entsize); | |
92 | } | |
93 | } | |
94 | ||
95 | static void bswap_sym(struct elf_sym *sym) | |
96 | { | |
97 | bswap32s(&sym->st_name); | |
98 | bswaptls(&sym->st_value); | |
99 | bswaptls(&sym->st_size); | |
100 | bswap16s(&sym->st_shndx); | |
101 | } | |
102 | ||
103 | #else /* ! BSWAP_NEEDED */ | |
104 | ||
105 | static void bswap_ehdr(struct elfhdr *ehdr) { } | |
106 | static void bswap_phdr(struct elf_phdr *phdr, int phnum) { } | |
107 | static void bswap_shdr(struct elf_shdr *shdr, int shnum) { } | |
108 | static void bswap_sym(struct elf_sym *sym) { } | |
109 | ||
110 | #endif /* ! BSWAP_NEEDED */ | |
111 | ||
112 | /* | |
113 | * 'copy_elf_strings()' copies argument/envelope strings from user | |
114 | * memory to free pages in kernel mem. These are in a format ready | |
115 | * to be put directly into the top of new user memory. | |
116 | * | |
117 | */ | |
118 | static abi_ulong copy_elf_strings(int argc, char **argv, void **page, | |
119 | abi_ulong p) | |
120 | { | |
121 | char *tmp, *tmp1, *pag = NULL; | |
122 | int len, offset = 0; | |
123 | ||
124 | if (!p) { | |
125 | return 0; /* bullet-proofing */ | |
126 | } | |
127 | while (argc-- > 0) { | |
128 | tmp = argv[argc]; | |
129 | if (!tmp) { | |
130 | fprintf(stderr, "VFS: argc is wrong"); | |
131 | exit(-1); | |
132 | } | |
133 | tmp1 = tmp; | |
134 | while (*tmp++); | |
135 | len = tmp - tmp1; | |
136 | if (p < len) { /* this shouldn't happen - 128kB */ | |
137 | return 0; | |
138 | } | |
139 | while (len) { | |
140 | --p; --tmp; --len; | |
141 | if (--offset < 0) { | |
142 | offset = p % TARGET_PAGE_SIZE; | |
143 | pag = (char *)page[p / TARGET_PAGE_SIZE]; | |
144 | if (!pag) { | |
145 | pag = g_try_malloc0(TARGET_PAGE_SIZE); | |
146 | page[p / TARGET_PAGE_SIZE] = pag; | |
147 | if (!pag) | |
148 | return 0; | |
149 | } | |
150 | } | |
151 | if (len == 0 || offset == 0) { | |
152 | *(pag + offset) = *tmp; | |
153 | } | |
154 | else { | |
155 | int bytes_to_copy = (len > offset) ? offset : len; | |
156 | tmp -= bytes_to_copy; | |
157 | p -= bytes_to_copy; | |
158 | offset -= bytes_to_copy; | |
159 | len -= bytes_to_copy; | |
160 | memcpy_fromfs(pag + offset, tmp, bytes_to_copy + 1); | |
161 | } | |
162 | } | |
163 | } | |
164 | return p; | |
165 | } | |
166 | ||
167 | static void setup_arg_pages(struct bsd_binprm *bprm, struct image_info *info, | |
168 | abi_ulong *stackp, abi_ulong *stringp) | |
169 | { | |
170 | abi_ulong stack_base, size; | |
171 | abi_long addr; | |
172 | ||
173 | /* Create enough stack to hold everything. If we don't use | |
174 | * it for args, we'll use it for something else... | |
175 | */ | |
176 | size = target_dflssiz; | |
177 | stack_base = TARGET_USRSTACK - size; | |
178 | addr = target_mmap(stack_base, | |
179 | size + qemu_host_page_size, | |
180 | PROT_READ | PROT_WRITE, | |
181 | MAP_PRIVATE | MAP_ANON, | |
182 | -1, 0); | |
183 | if (addr == -1) { | |
184 | perror("stk mmap"); | |
185 | exit(-1); | |
186 | } | |
187 | /* we reserve one extra page at the top of the stack as guard */ | |
188 | target_mprotect(addr + size, qemu_host_page_size, PROT_NONE); | |
189 | ||
190 | target_stksiz = size; | |
191 | target_stkbas = addr; | |
192 | ||
193 | if (setup_initial_stack(bprm, stackp, stringp) != 0) { | |
194 | perror("stk setup"); | |
195 | exit(-1); | |
196 | } | |
197 | } | |
198 | ||
199 | static void set_brk(abi_ulong start, abi_ulong end) | |
200 | { | |
201 | /* page-align the start and end addresses... */ | |
202 | start = HOST_PAGE_ALIGN(start); | |
203 | end = HOST_PAGE_ALIGN(end); | |
204 | if (end <= start) | |
205 | return; | |
206 | if (target_mmap(start, end - start, | |
207 | PROT_READ | PROT_WRITE | PROT_EXEC, | |
208 | MAP_FIXED | MAP_PRIVATE | MAP_ANON, -1, 0) == -1) { | |
209 | perror("cannot mmap brk"); | |
210 | exit(-1); | |
211 | } | |
212 | } | |
213 | ||
214 | ||
215 | /* We need to explicitly zero any fractional pages after the data | |
216 | section (i.e. bss). This would contain the junk from the file that | |
217 | should not be in memory. */ | |
218 | static void padzero(abi_ulong elf_bss, abi_ulong last_bss) | |
219 | { | |
220 | abi_ulong nbyte; | |
221 | ||
222 | if (elf_bss >= last_bss) | |
223 | return; | |
224 | ||
225 | /* XXX: this is really a hack : if the real host page size is | |
226 | smaller than the target page size, some pages after the end | |
227 | of the file may not be mapped. A better fix would be to | |
228 | patch target_mmap(), but it is more complicated as the file | |
229 | size must be known */ | |
230 | if (qemu_real_host_page_size < qemu_host_page_size) { | |
231 | abi_ulong end_addr, end_addr1; | |
232 | end_addr1 = REAL_HOST_PAGE_ALIGN(elf_bss); | |
233 | end_addr = HOST_PAGE_ALIGN(elf_bss); | |
234 | if (end_addr1 < end_addr) { | |
235 | mmap((void *)g2h_untagged(end_addr1), end_addr - end_addr1, | |
236 | PROT_READ | PROT_WRITE | PROT_EXEC, | |
237 | MAP_FIXED | MAP_PRIVATE | MAP_ANON, -1, 0); | |
238 | } | |
239 | } | |
240 | ||
241 | nbyte = elf_bss & (qemu_host_page_size - 1); | |
242 | if (nbyte) { | |
243 | nbyte = qemu_host_page_size - nbyte; | |
244 | do { | |
245 | /* FIXME - what to do if put_user() fails? */ | |
246 | put_user_u8(0, elf_bss); | |
247 | elf_bss++; | |
248 | } while (--nbyte); | |
249 | } | |
250 | } | |
251 | ||
252 | static abi_ulong load_elf_interp(struct elfhdr *interp_elf_ex, | |
253 | int interpreter_fd, | |
254 | abi_ulong *interp_load_addr) | |
255 | { | |
256 | struct elf_phdr *elf_phdata = NULL; | |
257 | struct elf_phdr *eppnt; | |
258 | abi_ulong load_addr = 0; | |
259 | int load_addr_set = 0; | |
260 | int retval; | |
261 | abi_ulong last_bss, elf_bss; | |
262 | abi_ulong error; | |
263 | int i; | |
264 | ||
265 | elf_bss = 0; | |
266 | last_bss = 0; | |
267 | error = 0; | |
268 | ||
269 | bswap_ehdr(interp_elf_ex); | |
270 | /* First of all, some simple consistency checks */ | |
271 | if ((interp_elf_ex->e_type != ET_EXEC && | |
272 | interp_elf_ex->e_type != ET_DYN) || | |
273 | !elf_check_arch(interp_elf_ex->e_machine)) { | |
274 | return ~((abi_ulong)0UL); | |
275 | } | |
276 | ||
277 | ||
278 | /* Now read in all of the header information */ | |
279 | ||
280 | if (sizeof(struct elf_phdr) * interp_elf_ex->e_phnum > TARGET_PAGE_SIZE) | |
281 | return ~(abi_ulong)0UL; | |
282 | ||
283 | elf_phdata = (struct elf_phdr *) | |
284 | malloc(sizeof(struct elf_phdr) * interp_elf_ex->e_phnum); | |
285 | ||
286 | if (!elf_phdata) | |
287 | return ~((abi_ulong)0UL); | |
288 | ||
289 | /* | |
290 | * If the size of this structure has changed, then punt, since | |
291 | * we will be doing the wrong thing. | |
292 | */ | |
293 | if (interp_elf_ex->e_phentsize != sizeof(struct elf_phdr)) { | |
294 | free(elf_phdata); | |
295 | return ~((abi_ulong)0UL); | |
296 | } | |
297 | ||
298 | retval = lseek(interpreter_fd, interp_elf_ex->e_phoff, SEEK_SET); | |
299 | if (retval >= 0) { | |
300 | retval = read(interpreter_fd, | |
301 | (char *) elf_phdata, | |
302 | sizeof(struct elf_phdr) * interp_elf_ex->e_phnum); | |
303 | } | |
304 | if (retval < 0) { | |
305 | perror("load_elf_interp"); | |
306 | exit(-1); | |
307 | free(elf_phdata); | |
308 | return retval; | |
309 | } | |
310 | bswap_phdr(elf_phdata, interp_elf_ex->e_phnum); | |
311 | ||
312 | if (interp_elf_ex->e_type == ET_DYN) { | |
313 | /* in order to avoid hardcoding the interpreter load | |
314 | address in qemu, we allocate a big enough memory zone */ | |
315 | error = target_mmap(0, INTERP_MAP_SIZE, | |
316 | PROT_NONE, MAP_PRIVATE | MAP_ANON, | |
317 | -1, 0); | |
318 | if (error == -1) { | |
319 | perror("mmap"); | |
320 | exit(-1); | |
321 | } | |
322 | load_addr = error; | |
323 | load_addr_set = 1; | |
324 | } | |
325 | ||
326 | eppnt = elf_phdata; | |
327 | for (i = 0; i < interp_elf_ex->e_phnum; i++, eppnt++) | |
328 | if (eppnt->p_type == PT_LOAD) { | |
329 | int elf_type = MAP_PRIVATE | MAP_DENYWRITE; | |
330 | int elf_prot = 0; | |
331 | abi_ulong vaddr = 0; | |
332 | abi_ulong k; | |
333 | ||
334 | if (eppnt->p_flags & PF_R) elf_prot = PROT_READ; | |
335 | if (eppnt->p_flags & PF_W) elf_prot |= PROT_WRITE; | |
336 | if (eppnt->p_flags & PF_X) elf_prot |= PROT_EXEC; | |
337 | if (interp_elf_ex->e_type == ET_EXEC || load_addr_set) { | |
338 | elf_type |= MAP_FIXED; | |
339 | vaddr = eppnt->p_vaddr; | |
340 | } | |
341 | error = target_mmap(load_addr + TARGET_ELF_PAGESTART(vaddr), | |
342 | eppnt->p_filesz + TARGET_ELF_PAGEOFFSET(eppnt->p_vaddr), | |
343 | elf_prot, | |
344 | elf_type, | |
345 | interpreter_fd, | |
346 | eppnt->p_offset - TARGET_ELF_PAGEOFFSET(eppnt->p_vaddr)); | |
347 | ||
348 | if (error == -1) { | |
349 | /* Real error */ | |
350 | close(interpreter_fd); | |
351 | free(elf_phdata); | |
352 | return ~((abi_ulong)0UL); | |
353 | } | |
354 | ||
355 | if (!load_addr_set && interp_elf_ex->e_type == ET_DYN) { | |
356 | load_addr = error; | |
357 | load_addr_set = 1; | |
358 | } | |
359 | ||
360 | /* | |
361 | * Find the end of the file mapping for this phdr, and keep | |
362 | * track of the largest address we see for this. | |
363 | */ | |
364 | k = load_addr + eppnt->p_vaddr + eppnt->p_filesz; | |
365 | if (k > elf_bss) elf_bss = k; | |
366 | ||
367 | /* | |
368 | * Do the same thing for the memory mapping - between | |
369 | * elf_bss and last_bss is the bss section. | |
370 | */ | |
371 | k = load_addr + eppnt->p_memsz + eppnt->p_vaddr; | |
372 | if (k > last_bss) last_bss = k; | |
373 | } | |
374 | ||
375 | /* Now use mmap to map the library into memory. */ | |
376 | ||
377 | close(interpreter_fd); | |
378 | ||
379 | /* | |
380 | * Now fill out the bss section. First pad the last page up | |
381 | * to the page boundary, and then perform a mmap to make sure | |
382 | * that there are zeromapped pages up to and including the last | |
383 | * bss page. | |
384 | */ | |
385 | padzero(elf_bss, last_bss); | |
386 | elf_bss = TARGET_ELF_PAGESTART(elf_bss + qemu_host_page_size - 1); /* What we have mapped so far */ | |
387 | ||
388 | /* Map the last of the bss segment */ | |
389 | if (last_bss > elf_bss) { | |
390 | target_mmap(elf_bss, last_bss - elf_bss, | |
391 | PROT_READ | PROT_WRITE | PROT_EXEC, | |
392 | MAP_FIXED | MAP_PRIVATE | MAP_ANON, -1, 0); | |
393 | } | |
394 | free(elf_phdata); | |
395 | ||
396 | *interp_load_addr = load_addr; | |
397 | return ((abi_ulong) interp_elf_ex->e_entry) + load_addr; | |
398 | } | |
399 | ||
400 | static int symfind(const void *s0, const void *s1) | |
401 | { | |
402 | target_ulong addr = *(target_ulong *)s0; | |
403 | struct elf_sym *sym = (struct elf_sym *)s1; | |
404 | int result = 0; | |
405 | if (addr < sym->st_value) { | |
406 | result = -1; | |
407 | } else if (addr >= sym->st_value + sym->st_size) { | |
408 | result = 1; | |
409 | } | |
410 | return result; | |
411 | } | |
412 | ||
413 | static const char *lookup_symbolxx(struct syminfo *s, target_ulong orig_addr) | |
414 | { | |
415 | #if ELF_CLASS == ELFCLASS32 | |
416 | struct elf_sym *syms = s->disas_symtab.elf32; | |
417 | #else | |
418 | struct elf_sym *syms = s->disas_symtab.elf64; | |
419 | #endif | |
420 | ||
421 | // binary search | |
422 | struct elf_sym *sym; | |
423 | ||
424 | sym = bsearch(&orig_addr, syms, s->disas_num_syms, sizeof(*syms), symfind); | |
425 | if (sym != NULL) { | |
426 | return s->disas_strtab + sym->st_name; | |
427 | } | |
428 | ||
429 | return ""; | |
430 | } | |
431 | ||
432 | /* FIXME: This should use elf_ops.h */ | |
433 | static int symcmp(const void *s0, const void *s1) | |
434 | { | |
435 | struct elf_sym *sym0 = (struct elf_sym *)s0; | |
436 | struct elf_sym *sym1 = (struct elf_sym *)s1; | |
437 | return (sym0->st_value < sym1->st_value) | |
438 | ? -1 | |
439 | : ((sym0->st_value > sym1->st_value) ? 1 : 0); | |
440 | } | |
441 | ||
442 | /* Best attempt to load symbols from this ELF object. */ | |
443 | static void load_symbols(struct elfhdr *hdr, int fd) | |
444 | { | |
445 | unsigned int i, nsyms; | |
446 | struct elf_shdr sechdr, symtab, strtab; | |
447 | char *strings; | |
448 | struct syminfo *s; | |
449 | struct elf_sym *syms, *new_syms; | |
450 | ||
451 | lseek(fd, hdr->e_shoff, SEEK_SET); | |
452 | for (i = 0; i < hdr->e_shnum; i++) { | |
453 | if (read(fd, &sechdr, sizeof(sechdr)) != sizeof(sechdr)) | |
454 | return; | |
455 | bswap_shdr(&sechdr, 1); | |
456 | if (sechdr.sh_type == SHT_SYMTAB) { | |
457 | symtab = sechdr; | |
458 | lseek(fd, hdr->e_shoff | |
459 | + sizeof(sechdr) * sechdr.sh_link, SEEK_SET); | |
460 | if (read(fd, &strtab, sizeof(strtab)) | |
461 | != sizeof(strtab)) | |
462 | return; | |
463 | bswap_shdr(&strtab, 1); | |
464 | goto found; | |
465 | } | |
466 | } | |
467 | return; /* Shouldn't happen... */ | |
468 | ||
469 | found: | |
470 | /* Now know where the strtab and symtab are. Snarf them. */ | |
471 | s = malloc(sizeof(*s)); | |
472 | syms = malloc(symtab.sh_size); | |
473 | if (!syms) { | |
474 | free(s); | |
475 | return; | |
476 | } | |
477 | s->disas_strtab = strings = malloc(strtab.sh_size); | |
478 | if (!s->disas_strtab) { | |
479 | free(s); | |
480 | free(syms); | |
481 | return; | |
482 | } | |
483 | ||
484 | lseek(fd, symtab.sh_offset, SEEK_SET); | |
485 | if (read(fd, syms, symtab.sh_size) != symtab.sh_size) { | |
486 | free(s); | |
487 | free(syms); | |
488 | free(strings); | |
489 | return; | |
490 | } | |
491 | ||
492 | nsyms = symtab.sh_size / sizeof(struct elf_sym); | |
493 | ||
494 | i = 0; | |
495 | while (i < nsyms) { | |
496 | bswap_sym(syms + i); | |
497 | // Throw away entries which we do not need. | |
498 | if (syms[i].st_shndx == SHN_UNDEF || | |
499 | syms[i].st_shndx >= SHN_LORESERVE || | |
500 | ELF_ST_TYPE(syms[i].st_info) != STT_FUNC) { | |
501 | nsyms--; | |
502 | if (i < nsyms) { | |
503 | syms[i] = syms[nsyms]; | |
504 | } | |
505 | continue; | |
506 | } | |
507 | i++; | |
508 | } | |
509 | ||
510 | /* Attempt to free the storage associated with the local symbols | |
511 | that we threw away. Whether or not this has any effect on the | |
512 | memory allocation depends on the malloc implementation and how | |
513 | many symbols we managed to discard. */ | |
514 | new_syms = realloc(syms, nsyms * sizeof(*syms)); | |
515 | if (new_syms == NULL) { | |
516 | free(s); | |
517 | free(syms); | |
518 | free(strings); | |
519 | return; | |
520 | } | |
521 | syms = new_syms; | |
522 | ||
523 | qsort(syms, nsyms, sizeof(*syms), symcmp); | |
524 | ||
525 | lseek(fd, strtab.sh_offset, SEEK_SET); | |
526 | if (read(fd, strings, strtab.sh_size) != strtab.sh_size) { | |
527 | free(s); | |
528 | free(syms); | |
529 | free(strings); | |
530 | return; | |
531 | } | |
532 | s->disas_num_syms = nsyms; | |
533 | #if ELF_CLASS == ELFCLASS32 | |
534 | s->disas_symtab.elf32 = syms; | |
535 | s->lookup_symbol = (lookup_symbol_t)lookup_symbolxx; | |
536 | #else | |
537 | s->disas_symtab.elf64 = syms; | |
538 | s->lookup_symbol = (lookup_symbol_t)lookup_symbolxx; | |
539 | #endif | |
540 | s->next = syminfos; | |
541 | syminfos = s; | |
542 | } | |
543 | ||
544 | int load_elf_binary(struct bsd_binprm *bprm, struct target_pt_regs *regs, | |
545 | struct image_info *info) | |
546 | { | |
547 | struct elfhdr elf_ex; | |
548 | struct elfhdr interp_elf_ex; | |
549 | int interpreter_fd = -1; /* avoid warning */ | |
550 | abi_ulong load_addr, load_bias; | |
551 | int load_addr_set = 0; | |
552 | int i; | |
553 | struct elf_phdr * elf_ppnt; | |
554 | struct elf_phdr *elf_phdata; | |
555 | abi_ulong elf_bss, k, elf_brk; | |
556 | int retval; | |
557 | char * elf_interpreter; | |
558 | abi_ulong elf_entry, interp_load_addr = 0; | |
559 | abi_ulong start_code, end_code, start_data, end_data; | |
560 | abi_ulong reloc_func_desc = 0; | |
561 | ||
562 | load_addr = 0; | |
563 | load_bias = 0; | |
564 | elf_ex = *((struct elfhdr *) bprm->buf); /* exec-header */ | |
565 | bswap_ehdr(&elf_ex); | |
566 | ||
567 | /* First of all, some simple consistency checks */ | |
568 | if ((elf_ex.e_type != ET_EXEC && elf_ex.e_type != ET_DYN) || | |
569 | (!elf_check_arch(elf_ex.e_machine))) { | |
570 | return -ENOEXEC; | |
571 | } | |
572 | ||
573 | bprm->p = copy_elf_strings(1, &bprm->filename, bprm->page, bprm->p); | |
574 | bprm->p = copy_elf_strings(bprm->envc, bprm->envp, bprm->page,bprm->p); | |
575 | bprm->p = copy_elf_strings(bprm->argc, bprm->argv, bprm->page,bprm->p); | |
576 | if (!bprm->p) { | |
577 | retval = -E2BIG; | |
578 | } | |
579 | ||
580 | /* Now read in all of the header information */ | |
581 | elf_phdata = (struct elf_phdr *)malloc(elf_ex.e_phentsize*elf_ex.e_phnum); | |
582 | if (elf_phdata == NULL) { | |
583 | return -ENOMEM; | |
584 | } | |
585 | ||
586 | retval = lseek(bprm->fd, elf_ex.e_phoff, SEEK_SET); | |
587 | if (retval > 0) { | |
588 | retval = read(bprm->fd, (char *)elf_phdata, | |
589 | elf_ex.e_phentsize * elf_ex.e_phnum); | |
590 | } | |
591 | ||
592 | if (retval < 0) { | |
593 | perror("load_elf_binary"); | |
594 | exit(-1); | |
595 | free(elf_phdata); | |
596 | return -errno; | |
597 | } | |
598 | ||
599 | bswap_phdr(elf_phdata, elf_ex.e_phnum); | |
600 | ||
601 | elf_ppnt = elf_phdata; | |
602 | ||
603 | elf_bss = 0; | |
604 | elf_brk = 0; | |
605 | ||
606 | ||
607 | elf_interpreter = NULL; | |
608 | start_code = ~((abi_ulong)0UL); | |
609 | end_code = 0; | |
610 | start_data = 0; | |
611 | end_data = 0; | |
612 | ||
613 | for (i = 0;i < elf_ex.e_phnum; i++) { | |
614 | if (elf_ppnt->p_type == PT_INTERP) { | |
615 | if (elf_interpreter != NULL) | |
616 | { | |
617 | free(elf_phdata); | |
618 | free(elf_interpreter); | |
619 | close(bprm->fd); | |
620 | return -EINVAL; | |
621 | } | |
622 | ||
623 | /* This is the program interpreter used for | |
624 | * shared libraries - for now assume that this | |
625 | * is an a.out format binary | |
626 | */ | |
627 | ||
628 | elf_interpreter = (char *)malloc(elf_ppnt->p_filesz); | |
629 | ||
630 | if (elf_interpreter == NULL) { | |
631 | free(elf_phdata); | |
632 | close(bprm->fd); | |
633 | return -ENOMEM; | |
634 | } | |
635 | ||
636 | retval = lseek(bprm->fd, elf_ppnt->p_offset, SEEK_SET); | |
637 | if (retval >= 0) { | |
638 | retval = read(bprm->fd, elf_interpreter, elf_ppnt->p_filesz); | |
639 | } | |
640 | if (retval < 0) { | |
641 | perror("load_elf_binary2"); | |
642 | exit(-1); | |
643 | } | |
644 | ||
645 | if (retval >= 0) { | |
646 | retval = open(path(elf_interpreter), O_RDONLY); | |
647 | if (retval >= 0) { | |
648 | interpreter_fd = retval; | |
649 | } | |
650 | else { | |
651 | perror(elf_interpreter); | |
652 | exit(-1); | |
653 | /* retval = -errno; */ | |
654 | } | |
655 | } | |
656 | ||
657 | if (retval >= 0) { | |
658 | retval = lseek(interpreter_fd, 0, SEEK_SET); | |
659 | if (retval >= 0) { | |
660 | retval = read(interpreter_fd, bprm->buf, 128); | |
661 | } | |
662 | } | |
663 | if (retval >= 0) { | |
664 | interp_elf_ex = *((struct elfhdr *) bprm->buf); /* elf exec-header */ | |
665 | } | |
666 | if (retval < 0) { | |
667 | perror("load_elf_binary3"); | |
668 | exit(-1); | |
669 | free(elf_phdata); | |
670 | free(elf_interpreter); | |
671 | close(bprm->fd); | |
672 | return retval; | |
673 | } | |
674 | } | |
675 | elf_ppnt++; | |
676 | } | |
677 | ||
678 | /* Some simple consistency checks for the interpreter */ | |
679 | if (elf_interpreter) { | |
680 | if (interp_elf_ex.e_ident[0] != 0x7f || | |
681 | strncmp((char *)&interp_elf_ex.e_ident[1], "ELF", 3) != 0) { | |
682 | free(elf_interpreter); | |
683 | free(elf_phdata); | |
684 | close(bprm->fd); | |
685 | return -ELIBBAD; | |
686 | } | |
687 | } | |
688 | ||
689 | /* OK, we are done with that, now set up the arg stuff, | |
690 | and then start this sucker up */ | |
691 | ||
692 | if (!bprm->p) { | |
693 | free(elf_interpreter); | |
694 | free(elf_phdata); | |
695 | close(bprm->fd); | |
696 | return -E2BIG; | |
697 | } | |
698 | ||
699 | /* OK, This is the point of no return */ | |
700 | info->end_data = 0; | |
701 | info->end_code = 0; | |
702 | info->start_mmap = (abi_ulong)ELF_START_MMAP; | |
703 | info->mmap = 0; | |
704 | elf_entry = (abi_ulong) elf_ex.e_entry; | |
705 | ||
706 | /* Do this so that we can load the interpreter, if need be. We will | |
707 | change some of these later */ | |
708 | info->rss = 0; | |
709 | setup_arg_pages(bprm, info, &bprm->p, &bprm->stringp); | |
710 | info->start_stack = bprm->p; | |
711 | ||
712 | /* Now we do a little grungy work by mmaping the ELF image into | |
713 | * the correct location in memory. At this point, we assume that | |
714 | * the image should be loaded at fixed address, not at a variable | |
715 | * address. | |
716 | */ | |
717 | ||
718 | for (i = 0, elf_ppnt = elf_phdata; i < elf_ex.e_phnum; i++, elf_ppnt++) { | |
719 | int elf_prot = 0; | |
720 | int elf_flags = 0; | |
721 | abi_ulong error; | |
722 | ||
723 | if (elf_ppnt->p_type != PT_LOAD) | |
724 | continue; | |
725 | ||
726 | if (elf_ppnt->p_flags & PF_R) elf_prot |= PROT_READ; | |
727 | if (elf_ppnt->p_flags & PF_W) elf_prot |= PROT_WRITE; | |
728 | if (elf_ppnt->p_flags & PF_X) elf_prot |= PROT_EXEC; | |
729 | elf_flags = MAP_PRIVATE | MAP_DENYWRITE; | |
730 | if (elf_ex.e_type == ET_EXEC || load_addr_set) { | |
731 | elf_flags |= MAP_FIXED; | |
732 | } else if (elf_ex.e_type == ET_DYN) { | |
733 | /* Try and get dynamic programs out of the way of the default mmap | |
734 | base, as well as whatever program they might try to exec. This | |
735 | is because the brk will follow the loader, and is not movable. */ | |
736 | /* NOTE: for qemu, we do a big mmap to get enough space | |
737 | without hardcoding any address */ | |
738 | error = target_mmap(0, ET_DYN_MAP_SIZE, | |
739 | PROT_NONE, MAP_PRIVATE | MAP_ANON, | |
740 | -1, 0); | |
741 | if (error == -1) { | |
742 | perror("mmap"); | |
743 | exit(-1); | |
744 | } | |
745 | load_bias = TARGET_ELF_PAGESTART(error - elf_ppnt->p_vaddr); | |
746 | } | |
747 | ||
748 | error = target_mmap(TARGET_ELF_PAGESTART(load_bias + elf_ppnt->p_vaddr), | |
749 | (elf_ppnt->p_filesz + | |
750 | TARGET_ELF_PAGEOFFSET(elf_ppnt->p_vaddr)), | |
751 | elf_prot, | |
752 | (MAP_FIXED | MAP_PRIVATE | MAP_DENYWRITE), | |
753 | bprm->fd, | |
754 | (elf_ppnt->p_offset - | |
755 | TARGET_ELF_PAGEOFFSET(elf_ppnt->p_vaddr))); | |
756 | if (error == -1) { | |
757 | perror("mmap"); | |
758 | exit(-1); | |
759 | } | |
760 | ||
761 | if (!load_addr_set) { | |
762 | load_addr_set = 1; | |
763 | load_addr = elf_ppnt->p_vaddr - elf_ppnt->p_offset; | |
764 | if (elf_ex.e_type == ET_DYN) { | |
765 | load_bias += error - | |
766 | TARGET_ELF_PAGESTART(load_bias + elf_ppnt->p_vaddr); | |
767 | load_addr += load_bias; | |
768 | reloc_func_desc = load_bias; | |
769 | } | |
770 | } | |
771 | k = elf_ppnt->p_vaddr; | |
772 | if (k < start_code) | |
773 | start_code = k; | |
774 | if (start_data < k) | |
775 | start_data = k; | |
776 | k = elf_ppnt->p_vaddr + elf_ppnt->p_filesz; | |
777 | if (k > elf_bss) | |
778 | elf_bss = k; | |
779 | if ((elf_ppnt->p_flags & PF_X) && end_code < k) | |
780 | end_code = k; | |
781 | if (end_data < k) | |
782 | end_data = k; | |
783 | k = elf_ppnt->p_vaddr + elf_ppnt->p_memsz; | |
784 | if (k > elf_brk) elf_brk = k; | |
785 | } | |
786 | ||
787 | elf_entry += load_bias; | |
788 | elf_bss += load_bias; | |
789 | elf_brk += load_bias; | |
790 | start_code += load_bias; | |
791 | end_code += load_bias; | |
792 | start_data += load_bias; | |
793 | end_data += load_bias; | |
794 | ||
795 | if (elf_interpreter) { | |
796 | elf_entry = load_elf_interp(&interp_elf_ex, interpreter_fd, | |
797 | &interp_load_addr); | |
798 | reloc_func_desc = interp_load_addr; | |
799 | ||
800 | close(interpreter_fd); | |
801 | free(elf_interpreter); | |
802 | ||
803 | if (elf_entry == ~((abi_ulong)0UL)) { | |
804 | printf("Unable to load interpreter\n"); | |
805 | free(elf_phdata); | |
806 | exit(-1); | |
807 | return 0; | |
808 | } | |
809 | } | |
810 | ||
811 | free(elf_phdata); | |
812 | ||
813 | if (qemu_log_enabled()) | |
814 | load_symbols(&elf_ex, bprm->fd); | |
815 | ||
816 | close(bprm->fd); | |
817 | ||
818 | bprm->p = target_create_elf_tables(bprm->p, bprm->argc, bprm->envc, | |
819 | bprm->stringp, &elf_ex, load_addr, | |
820 | load_bias, interp_load_addr, info); | |
821 | info->load_addr = reloc_func_desc; | |
822 | info->start_brk = info->brk = elf_brk; | |
823 | info->end_code = end_code; | |
824 | info->start_code = start_code; | |
825 | info->start_data = start_data; | |
826 | info->end_data = end_data; | |
827 | info->start_stack = bprm->p; | |
828 | ||
829 | /* Calling set_brk effectively mmaps the pages that we need for the bss and break | |
830 | sections */ | |
831 | set_brk(elf_bss, elf_brk); | |
832 | ||
833 | padzero(elf_bss, elf_brk); | |
834 | ||
835 | info->entry = elf_entry; | |
836 | ||
837 | return 0; | |
838 | } | |
839 | ||
840 | void do_init_thread(struct target_pt_regs *regs, struct image_info *infop) | |
841 | { | |
842 | ||
843 | target_thread_init(regs, infop); | |
844 | } |