1 /*-
2 * Copyright (c) 1998 Michael Smith <msmith@freebsd.org>
3 * Copyright (c) 1998 Peter Wemm <peter@freebsd.org>
4 * All rights reserved.
5 *
6 * Redistribution and use in source and binary forms, with or without
7 * modification, are permitted provided that the following conditions
8 * are met:
9 * 1. Redistributions of source code must retain the above copyright
10 * notice, this list of conditions and the following disclaimer.
11 * 2. Redistributions in binary form must reproduce the above copyright
12 * notice, this list of conditions and the following disclaimer in the
13 * documentation and/or other materials provided with the distribution.
14 *
15 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
16 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
17 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
18 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
19 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
20 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
21 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
22 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
23 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
24 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
25 * SUCH DAMAGE.
26 */
27
28 #include <sys/cdefs.h>
29 __FBSDID("$FreeBSD$");
30
31 #include <sys/param.h>
32 #include <sys/exec.h>
33 #include <sys/linker.h>
34 #include <sys/module.h>
35 #include <sys/stdint.h>
36 #include <string.h>
37 #include <machine/elf.h>
38 #include <stand.h>
39 #define FREEBSD_ELF
40 #include <link.h>
41
42 #include "bootstrap.h"
43
44 #define COPYOUT(s,d,l) archsw.arch_copyout((vm_offset_t)(s), d, l)
45
46 #if defined(__i386__) && __ELF_WORD_SIZE == 64
47 #undef ELF_TARG_CLASS
48 #undef ELF_TARG_MACH
49 #define ELF_TARG_CLASS ELFCLASS64
50 #define ELF_TARG_MACH EM_X86_64
51 #endif
52
53 typedef struct elf_file {
54 Elf_Phdr *ph;
55 Elf_Ehdr *ehdr;
56 Elf_Sym *symtab;
57 Elf_Hashelt *hashtab;
58 Elf_Hashelt nbuckets;
59 Elf_Hashelt nchains;
60 Elf_Hashelt *buckets;
61 Elf_Hashelt *chains;
62 Elf_Rel *rel;
63 size_t relsz;
64 Elf_Rela *rela;
65 size_t relasz;
66 char *strtab;
67 size_t strsz;
68 int fd;
69 caddr_t firstpage;
70 size_t firstlen;
71 int kernel;
72 u_int64_t off;
73 } *elf_file_t;
74
75 static int __elfN(loadimage)(struct preloaded_file *mp, elf_file_t ef, u_int64_t loadaddr);
76 static int __elfN(lookup_symbol)(struct preloaded_file *mp, elf_file_t ef, const char* name, Elf_Sym* sym);
77 static int __elfN(reloc_ptr)(struct preloaded_file *mp, elf_file_t ef,
78 Elf_Addr p, void *val, size_t len);
79 static int __elfN(parse_modmetadata)(struct preloaded_file *mp, elf_file_t ef,
80 Elf_Addr p_start, Elf_Addr p_end);
81 static symaddr_fn __elfN(symaddr);
82 static char *fake_modname(const char *name);
83
84 const char *__elfN(kerneltype) = "elf kernel";
85 const char *__elfN(moduletype) = "elf module";
86
87 u_int64_t __elfN(relocation_offset) = 0;
88
89 static int
__elfN(load_elf_header)90 __elfN(load_elf_header)(char *filename, elf_file_t ef)
91 {
92 ssize_t bytes_read;
93 Elf_Ehdr *ehdr;
94 int err;
95
96 /*
97 * Open the image, read and validate the ELF header
98 */
99 if (filename == NULL) /* can't handle nameless */
100 return (EFTYPE);
101 if ((ef->fd = open(filename, O_RDONLY)) == -1)
102 return (errno);
103 ef->firstpage = malloc(PAGE_SIZE);
104 if (ef->firstpage == NULL) {
105 close(ef->fd);
106 return (ENOMEM);
107 }
108 bytes_read = read(ef->fd, ef->firstpage, PAGE_SIZE);
109 ef->firstlen = (size_t)bytes_read;
110 if (bytes_read < 0 || ef->firstlen <= sizeof(Elf_Ehdr)) {
111 err = EFTYPE; /* could be EIO, but may be small file */
112 goto error;
113 }
114 ehdr = ef->ehdr = (Elf_Ehdr *)ef->firstpage;
115
116 /* Is it ELF? */
117 if (!IS_ELF(*ehdr)) {
118 err = EFTYPE;
119 goto error;
120 }
121 if (ehdr->e_ident[EI_CLASS] != ELF_TARG_CLASS || /* Layout ? */
122 ehdr->e_ident[EI_DATA] != ELF_TARG_DATA ||
123 ehdr->e_ident[EI_VERSION] != EV_CURRENT || /* Version ? */
124 ehdr->e_version != EV_CURRENT ||
125 ehdr->e_machine != ELF_TARG_MACH) { /* Machine ? */
126 err = EFTYPE;
127 goto error;
128 }
129
130 return (0);
131
132 error:
133 if (ef->firstpage != NULL) {
134 free(ef->firstpage);
135 ef->firstpage = NULL;
136 }
137 if (ef->fd != -1) {
138 close(ef->fd);
139 ef->fd = -1;
140 }
141 return (err);
142 }
143
144 /*
145 * Attempt to load the file (file) as an ELF module. It will be stored at
146 * (dest), and a pointer to a module structure describing the loaded object
147 * will be saved in (result).
148 */
149 int
__elfN(loadfile)150 __elfN(loadfile)(char *filename, u_int64_t dest, struct preloaded_file **result)
151 {
152 return (__elfN(loadfile_raw)(filename, dest, result, 0));
153 }
154
155 int
__elfN(loadfile_raw)156 __elfN(loadfile_raw)(char *filename, u_int64_t dest,
157 struct preloaded_file **result, int multiboot)
158 {
159 struct preloaded_file *fp, *kfp;
160 struct elf_file ef;
161 Elf_Ehdr *ehdr;
162 int err;
163
164 fp = NULL;
165 bzero(&ef, sizeof(struct elf_file));
166 ef.fd = -1;
167
168 err = __elfN(load_elf_header)(filename, &ef);
169 if (err != 0)
170 return (err);
171
172 ehdr = ef.ehdr;
173
174 /*
175 * Check to see what sort of module we are.
176 */
177 kfp = file_findfile(NULL, __elfN(kerneltype));
178 #ifdef __powerpc__
179 /*
180 * Kernels can be ET_DYN, so just assume the first loaded object is the
181 * kernel. This assumption will be checked later.
182 */
183 if (kfp == NULL)
184 ef.kernel = 1;
185 #endif
186 if (ef.kernel || ehdr->e_type == ET_EXEC) {
187 /* Looks like a kernel */
188 if (kfp != NULL) {
189 printf("elf" __XSTRING(__ELF_WORD_SIZE) "_loadfile: kernel already loaded\n");
190 err = EPERM;
191 goto oerr;
192 }
193 /*
194 * Calculate destination address based on kernel entrypoint.
195 *
196 * For ARM, the destination address is independent of any values in the
197 * elf header (an ARM kernel can be loaded at any 2MB boundary), so we
198 * leave dest set to the value calculated by archsw.arch_loadaddr() and
199 * passed in to this function.
200 */
201 #ifndef __arm__
202 if (ehdr->e_type == ET_EXEC)
203 dest = (ehdr->e_entry & ~PAGE_MASK);
204 #endif
205 if ((ehdr->e_entry & ~PAGE_MASK) == 0) {
206 printf("elf" __XSTRING(__ELF_WORD_SIZE) "_loadfile: not a kernel (maybe static binary?)\n");
207 err = EPERM;
208 goto oerr;
209 }
210 ef.kernel = 1;
211
212 } else if (ehdr->e_type == ET_DYN) {
213 /* Looks like a kld module */
214 if (multiboot != 0) {
215 printf("elf" __XSTRING(__ELF_WORD_SIZE) "_loadfile: can't load module as multiboot\n");
216 err = EPERM;
217 goto oerr;
218 }
219 if (kfp == NULL) {
220 printf("elf" __XSTRING(__ELF_WORD_SIZE) "_loadfile: can't load module before kernel\n");
221 err = EPERM;
222 goto oerr;
223 }
224 if (strcmp(__elfN(kerneltype), kfp->f_type)) {
225 printf("elf" __XSTRING(__ELF_WORD_SIZE) "_loadfile: can't load module with kernel type '%s'\n", kfp->f_type);
226 err = EPERM;
227 goto oerr;
228 }
229 /* Looks OK, got ahead */
230 ef.kernel = 0;
231
232 } else {
233 err = EFTYPE;
234 goto oerr;
235 }
236
237 if (archsw.arch_loadaddr != NULL)
238 dest = archsw.arch_loadaddr(LOAD_ELF, ehdr, dest);
239 else
240 dest = roundup(dest, PAGE_SIZE);
241
242 /*
243 * Ok, we think we should handle this.
244 */
245 fp = file_alloc();
246 if (fp == NULL) {
247 printf("elf" __XSTRING(__ELF_WORD_SIZE) "_loadfile: cannot allocate module info\n");
248 err = EPERM;
249 goto out;
250 }
251 if (ef.kernel == 1 && multiboot == 0)
252 setenv("kernelname", filename, 1);
253 fp->f_name = strdup(filename);
254 if (multiboot == 0)
255 fp->f_type = strdup(ef.kernel ?
256 __elfN(kerneltype) : __elfN(moduletype));
257 else
258 fp->f_type = strdup("elf multiboot kernel");
259
260 #ifdef ELF_VERBOSE
261 if (ef.kernel)
262 printf("%s entry at 0x%jx\n", filename, (uintmax_t)ehdr->e_entry);
263 #else
264 printf("%s ", filename);
265 #endif
266
267 fp->f_size = __elfN(loadimage)(fp, &ef, dest);
268 if (fp->f_size == 0 || fp->f_addr == 0)
269 goto ioerr;
270
271 /* save exec header as metadata */
272 file_addmetadata(fp, MODINFOMD_ELFHDR, sizeof(*ehdr), ehdr);
273
274 /* Load OK, return module pointer */
275 *result = (struct preloaded_file *)fp;
276 err = 0;
277 goto out;
278
279 ioerr:
280 err = EIO;
281 oerr:
282 file_discard(fp);
283 out:
284 if (ef.firstpage)
285 free(ef.firstpage);
286 if (ef.fd != -1)
287 close(ef.fd);
288 return(err);
289 }
290
291 /*
292 * With the file (fd) open on the image, and (ehdr) containing
293 * the Elf header, load the image at (off)
294 */
295 static int
__elfN(loadimage)296 __elfN(loadimage)(struct preloaded_file *fp, elf_file_t ef, u_int64_t off)
297 {
298 int i;
299 u_int j;
300 Elf_Ehdr *ehdr;
301 Elf_Phdr *phdr, *php;
302 Elf_Shdr *shdr;
303 char *shstr;
304 int ret;
305 vm_offset_t firstaddr;
306 vm_offset_t lastaddr;
307 size_t chunk;
308 ssize_t result;
309 Elf_Addr ssym, esym;
310 Elf_Dyn *dp;
311 Elf_Addr adp;
312 Elf_Addr ctors;
313 int ndp;
314 int symstrindex;
315 int symtabindex;
316 Elf_Size size;
317 u_int fpcopy;
318 Elf_Sym sym;
319 Elf_Addr p_start, p_end;
320
321 dp = NULL;
322 shdr = NULL;
323 ret = 0;
324 firstaddr = lastaddr = 0;
325 ehdr = ef->ehdr;
326 if (ehdr->e_type == ET_EXEC) {
327 #if defined(__i386__) || defined(__amd64__)
328 #if __ELF_WORD_SIZE == 64
329 off = - (off & 0xffffffffff000000ull);/* x86_64 relocates after locore */
330 #else
331 off = - (off & 0xff000000u); /* i386 relocates after locore */
332 #endif
333 #elif defined(__powerpc__)
334 /*
335 * On the purely virtual memory machines like e500, the kernel is
336 * linked against its final VA range, which is most often not
337 * available at the loader stage, but only after kernel initializes
338 * and completes its VM settings. In such cases we cannot use p_vaddr
339 * field directly to load ELF segments, but put them at some
340 * 'load-time' locations.
341 */
342 if (off & 0xf0000000u) {
343 off = -(off & 0xf0000000u);
344 /*
345 * XXX the physical load address should not be hardcoded. Note
346 * that the Book-E kernel assumes that it's loaded at a 16MB
347 * boundary for now...
348 */
349 off += 0x01000000;
350 ehdr->e_entry += off;
351 #ifdef ELF_VERBOSE
352 printf("Converted entry 0x%08x\n", ehdr->e_entry);
353 #endif
354 } else
355 off = 0;
356 #elif defined(__arm__)
357 /*
358 * The elf headers in arm kernels specify virtual addresses in all
359 * header fields, even the ones that should be physical addresses.
360 * We assume the entry point is in the first page, and masking the page
361 * offset will leave us with the virtual address the kernel was linked
362 * at. We subtract that from the load offset, making 'off' into the
363 * value which, when added to a virtual address in an elf header,
364 * translates it to a physical address. We do the va->pa conversion on
365 * the entry point address in the header now, so that later we can
366 * launch the kernel by just jumping to that address.
367 */
368 off -= ehdr->e_entry & ~PAGE_MASK;
369 ehdr->e_entry += off;
370 #ifdef ELF_VERBOSE
371 printf("ehdr->e_entry 0x%08x, va<->pa off %llx\n", ehdr->e_entry, off);
372 #endif
373 #else
374 off = 0; /* other archs use direct mapped kernels */
375 #endif
376 }
377 ef->off = off;
378
379 if (ef->kernel)
380 __elfN(relocation_offset) = off;
381
382 if ((ehdr->e_phoff + ehdr->e_phnum * sizeof(*phdr)) > ef->firstlen) {
383 printf("elf" __XSTRING(__ELF_WORD_SIZE) "_loadimage: program header not within first page\n");
384 goto out;
385 }
386 phdr = (Elf_Phdr *)(ef->firstpage + ehdr->e_phoff);
387
388 for (i = 0; i < ehdr->e_phnum; i++) {
389 /* We want to load PT_LOAD segments only.. */
390 if (phdr[i].p_type != PT_LOAD)
391 continue;
392
393 #ifdef ELF_VERBOSE
394 printf("Segment: 0x%lx@0x%lx -> 0x%lx-0x%lx",
395 (long)phdr[i].p_filesz, (long)phdr[i].p_offset,
396 (long)(phdr[i].p_vaddr + off),
397 (long)(phdr[i].p_vaddr + off + phdr[i].p_memsz - 1));
398 #else
399 if ((phdr[i].p_flags & PF_W) == 0) {
400 printf("text=0x%lx ", (long)phdr[i].p_filesz);
401 } else {
402 printf("data=0x%lx", (long)phdr[i].p_filesz);
403 if (phdr[i].p_filesz < phdr[i].p_memsz)
404 printf("+0x%lx", (long)(phdr[i].p_memsz -phdr[i].p_filesz));
405 printf(" ");
406 }
407 #endif
408 fpcopy = 0;
409 if (ef->firstlen > phdr[i].p_offset) {
410 fpcopy = ef->firstlen - phdr[i].p_offset;
411 archsw.arch_copyin(ef->firstpage + phdr[i].p_offset,
412 phdr[i].p_vaddr + off, fpcopy);
413 }
414 if (phdr[i].p_filesz > fpcopy) {
415 if (kern_pread(ef->fd, phdr[i].p_vaddr + off + fpcopy,
416 phdr[i].p_filesz - fpcopy, phdr[i].p_offset + fpcopy) != 0) {
417 printf("\nelf" __XSTRING(__ELF_WORD_SIZE)
418 "_loadimage: read failed\n");
419 goto out;
420 }
421 }
422 /* clear space from oversized segments; eg: bss */
423 if (phdr[i].p_filesz < phdr[i].p_memsz) {
424 #ifdef ELF_VERBOSE
425 printf(" (bss: 0x%lx-0x%lx)",
426 (long)(phdr[i].p_vaddr + off + phdr[i].p_filesz),
427 (long)(phdr[i].p_vaddr + off + phdr[i].p_memsz - 1));
428 #endif
429
430 kern_bzero(phdr[i].p_vaddr + off + phdr[i].p_filesz,
431 phdr[i].p_memsz - phdr[i].p_filesz);
432 }
433 #ifdef ELF_VERBOSE
434 printf("\n");
435 #endif
436
437 if (archsw.arch_loadseg != NULL)
438 archsw.arch_loadseg(ehdr, phdr + i, off);
439
440 if (firstaddr == 0 || firstaddr > (phdr[i].p_vaddr + off))
441 firstaddr = phdr[i].p_vaddr + off;
442 if (lastaddr == 0 || lastaddr < (phdr[i].p_vaddr + off + phdr[i].p_memsz))
443 lastaddr = phdr[i].p_vaddr + off + phdr[i].p_memsz;
444 }
445 lastaddr = roundup(lastaddr, sizeof(long));
446
447 /*
448 * Get the section headers. We need this for finding the .ctors
449 * section as well as for loading any symbols. Both may be hard
450 * to do if reading from a .gz file as it involves seeking. I
451 * think the rule is going to have to be that you must strip a
452 * file to remove symbols before gzipping it.
453 */
454 chunk = ehdr->e_shnum * ehdr->e_shentsize;
455 if (chunk == 0 || ehdr->e_shoff == 0)
456 goto nosyms;
457 shdr = alloc_pread(ef->fd, ehdr->e_shoff, chunk);
458 if (shdr == NULL) {
459 printf("\nelf" __XSTRING(__ELF_WORD_SIZE)
460 "_loadimage: failed to read section headers");
461 goto nosyms;
462 }
463 file_addmetadata(fp, MODINFOMD_SHDR, chunk, shdr);
464
465 /*
466 * Read the section string table and look for the .ctors section.
467 * We need to tell the kernel where it is so that it can call the
468 * ctors.
469 */
470 chunk = shdr[ehdr->e_shstrndx].sh_size;
471 if (chunk) {
472 shstr = alloc_pread(ef->fd, shdr[ehdr->e_shstrndx].sh_offset, chunk);
473 if (shstr) {
474 for (i = 0; i < ehdr->e_shnum; i++) {
475 if (strcmp(shstr + shdr[i].sh_name, ".ctors") != 0)
476 continue;
477 ctors = shdr[i].sh_addr;
478 file_addmetadata(fp, MODINFOMD_CTORS_ADDR, sizeof(ctors),
479 &ctors);
480 size = shdr[i].sh_size;
481 file_addmetadata(fp, MODINFOMD_CTORS_SIZE, sizeof(size),
482 &size);
483 break;
484 }
485 free(shstr);
486 }
487 }
488
489 /*
490 * Now load any symbols.
491 */
492 symtabindex = -1;
493 symstrindex = -1;
494 for (i = 0; i < ehdr->e_shnum; i++) {
495 if (shdr[i].sh_type != SHT_SYMTAB)
496 continue;
497 for (j = 0; j < ehdr->e_phnum; j++) {
498 if (phdr[j].p_type != PT_LOAD)
499 continue;
500 if (shdr[i].sh_offset >= phdr[j].p_offset &&
501 (shdr[i].sh_offset + shdr[i].sh_size <=
502 phdr[j].p_offset + phdr[j].p_filesz)) {
503 shdr[i].sh_offset = 0;
504 shdr[i].sh_size = 0;
505 break;
506 }
507 }
508 if (shdr[i].sh_offset == 0 || shdr[i].sh_size == 0)
509 continue; /* alread loaded in a PT_LOAD above */
510 /* Save it for loading below */
511 symtabindex = i;
512 symstrindex = shdr[i].sh_link;
513 }
514 if (symtabindex < 0 || symstrindex < 0)
515 goto nosyms;
516
517 /* Ok, committed to a load. */
518 #ifndef ELF_VERBOSE
519 printf("syms=[");
520 #endif
521 ssym = lastaddr;
522 for (i = symtabindex; i >= 0; i = symstrindex) {
523 #ifdef ELF_VERBOSE
524 char *secname;
525
526 switch(shdr[i].sh_type) {
527 case SHT_SYMTAB: /* Symbol table */
528 secname = "symtab";
529 break;
530 case SHT_STRTAB: /* String table */
531 secname = "strtab";
532 break;
533 default:
534 secname = "WHOA!!";
535 break;
536 }
537 #endif
538
539 size = shdr[i].sh_size;
540 archsw.arch_copyin(&size, lastaddr, sizeof(size));
541 lastaddr += sizeof(size);
542
543 #ifdef ELF_VERBOSE
544 printf("\n%s: 0x%jx@0x%jx -> 0x%jx-0x%jx", secname,
545 (uintmax_t)shdr[i].sh_size, (uintmax_t)shdr[i].sh_offset,
546 (uintmax_t)lastaddr, (uintmax_t)(lastaddr + shdr[i].sh_size));
547 #else
548 if (i == symstrindex)
549 printf("+");
550 printf("0x%lx+0x%lx", (long)sizeof(size), (long)size);
551 #endif
552
553 if (lseek(ef->fd, (off_t)shdr[i].sh_offset, SEEK_SET) == -1) {
554 printf("\nelf" __XSTRING(__ELF_WORD_SIZE) "_loadimage: could not seek for symbols - skipped!");
555 lastaddr = ssym;
556 ssym = 0;
557 goto nosyms;
558 }
559 result = archsw.arch_readin(ef->fd, lastaddr, shdr[i].sh_size);
560 if (result < 0 || (size_t)result != shdr[i].sh_size) {
561 printf("\nelf" __XSTRING(__ELF_WORD_SIZE) "_loadimage: could not read symbols - skipped! (%ju != %ju)", (uintmax_t)result,
562 (uintmax_t)shdr[i].sh_size);
563 lastaddr = ssym;
564 ssym = 0;
565 goto nosyms;
566 }
567 /* Reset offsets relative to ssym */
568 lastaddr += shdr[i].sh_size;
569 lastaddr = roundup(lastaddr, sizeof(size));
570 if (i == symtabindex)
571 symtabindex = -1;
572 else if (i == symstrindex)
573 symstrindex = -1;
574 }
575 esym = lastaddr;
576 #ifndef ELF_VERBOSE
577 printf("]");
578 #endif
579
580 file_addmetadata(fp, MODINFOMD_SSYM, sizeof(ssym), &ssym);
581 file_addmetadata(fp, MODINFOMD_ESYM, sizeof(esym), &esym);
582
583 nosyms:
584 printf("\n");
585
586 ret = lastaddr - firstaddr;
587 fp->f_addr = firstaddr;
588
589 php = NULL;
590 for (i = 0; i < ehdr->e_phnum; i++) {
591 if (phdr[i].p_type == PT_DYNAMIC) {
592 php = phdr + i;
593 adp = php->p_vaddr;
594 file_addmetadata(fp, MODINFOMD_DYNAMIC, sizeof(adp), &adp);
595 break;
596 }
597 }
598
599 if (php == NULL) /* this is bad, we cannot get to symbols or _DYNAMIC */
600 goto out;
601
602 ndp = php->p_filesz / sizeof(Elf_Dyn);
603 if (ndp == 0)
604 goto out;
605 dp = malloc(php->p_filesz);
606 if (dp == NULL)
607 goto out;
608 archsw.arch_copyout(php->p_vaddr + off, dp, php->p_filesz);
609
610 ef->strsz = 0;
611 for (i = 0; i < ndp; i++) {
612 if (dp[i].d_tag == 0)
613 break;
614 switch (dp[i].d_tag) {
615 case DT_HASH:
616 ef->hashtab = (Elf_Hashelt*)(uintptr_t)(dp[i].d_un.d_ptr + off);
617 break;
618 case DT_STRTAB:
619 ef->strtab = (char *)(uintptr_t)(dp[i].d_un.d_ptr + off);
620 break;
621 case DT_STRSZ:
622 ef->strsz = dp[i].d_un.d_val;
623 break;
624 case DT_SYMTAB:
625 ef->symtab = (Elf_Sym*)(uintptr_t)(dp[i].d_un.d_ptr + off);
626 break;
627 case DT_REL:
628 ef->rel = (Elf_Rel *)(uintptr_t)(dp[i].d_un.d_ptr + off);
629 break;
630 case DT_RELSZ:
631 ef->relsz = dp[i].d_un.d_val;
632 break;
633 case DT_RELA:
634 ef->rela = (Elf_Rela *)(uintptr_t)(dp[i].d_un.d_ptr + off);
635 break;
636 case DT_RELASZ:
637 ef->relasz = dp[i].d_un.d_val;
638 break;
639 default:
640 break;
641 }
642 }
643 if (ef->hashtab == NULL || ef->symtab == NULL ||
644 ef->strtab == NULL || ef->strsz == 0)
645 goto out;
646 COPYOUT(ef->hashtab, &ef->nbuckets, sizeof(ef->nbuckets));
647 COPYOUT(ef->hashtab + 1, &ef->nchains, sizeof(ef->nchains));
648 ef->buckets = ef->hashtab + 2;
649 ef->chains = ef->buckets + ef->nbuckets;
650
651 if (__elfN(lookup_symbol)(fp, ef, "__start_set_modmetadata_set", &sym) != 0)
652 return 0;
653 p_start = sym.st_value + ef->off;
654 if (__elfN(lookup_symbol)(fp, ef, "__stop_set_modmetadata_set", &sym) != 0)
655 return ENOENT;
656 p_end = sym.st_value + ef->off;
657
658 if (__elfN(parse_modmetadata)(fp, ef, p_start, p_end) == 0)
659 goto out;
660
661 if (ef->kernel) /* kernel must not depend on anything */
662 goto out;
663
664 out:
665 if (dp)
666 free(dp);
667 if (shdr)
668 free(shdr);
669 return ret;
670 }
671
672 static char invalid_name[] = "bad";
673
674 char *
fake_modname(const char * name)675 fake_modname(const char *name)
676 {
677 const char *sp, *ep;
678 char *fp;
679 size_t len;
680
681 sp = strrchr(name, '/');
682 if (sp)
683 sp++;
684 else
685 sp = name;
686 ep = strrchr(name, '.');
687 if (ep) {
688 if (ep == name) {
689 sp = invalid_name;
690 ep = invalid_name + sizeof(invalid_name) - 1;
691 }
692 } else
693 ep = name + strlen(name);
694 len = ep - sp;
695 fp = malloc(len + 1);
696 if (fp == NULL)
697 return NULL;
698 memcpy(fp, sp, len);
699 fp[len] = '\0';
700 return fp;
701 }
702
703 #if (defined(__i386__) || defined(__powerpc__)) && __ELF_WORD_SIZE == 64
704 struct mod_metadata64 {
705 int md_version; /* structure version MDTV_* */
706 int md_type; /* type of entry MDT_* */
707 u_int64_t md_data; /* specific data */
708 u_int64_t md_cval; /* common string label */
709 };
710 #endif
711 #if defined(__amd64__) && __ELF_WORD_SIZE == 32
712 struct mod_metadata32 {
713 int md_version; /* structure version MDTV_* */
714 int md_type; /* type of entry MDT_* */
715 u_int32_t md_data; /* specific data */
716 u_int32_t md_cval; /* common string label */
717 };
718 #endif
719
720 int
__elfN(load_modmetadata)721 __elfN(load_modmetadata)(struct preloaded_file *fp, u_int64_t dest)
722 {
723 struct elf_file ef;
724 int err, i, j;
725 Elf_Shdr *sh_meta, *shdr = NULL;
726 Elf_Shdr *sh_data[2];
727 char *shstrtab = NULL;
728 size_t size;
729 Elf_Addr p_start, p_end;
730
731 bzero(&ef, sizeof(struct elf_file));
732 ef.fd = -1;
733
734 err = __elfN(load_elf_header)(fp->f_name, &ef);
735 if (err != 0)
736 goto out;
737
738 if (ef.kernel == 1 || ef.ehdr->e_type == ET_EXEC) {
739 ef.kernel = 1;
740 } else if (ef.ehdr->e_type != ET_DYN) {
741 err = EFTYPE;
742 goto out;
743 }
744
745 size = ef.ehdr->e_shnum * ef.ehdr->e_shentsize;
746 shdr = alloc_pread(ef.fd, ef.ehdr->e_shoff, size);
747 if (shdr == NULL) {
748 err = ENOMEM;
749 goto out;
750 }
751
752 /* Load shstrtab. */
753 shstrtab = alloc_pread(ef.fd, shdr[ef.ehdr->e_shstrndx].sh_offset,
754 shdr[ef.ehdr->e_shstrndx].sh_size);
755 if (shstrtab == NULL) {
756 printf("\nelf" __XSTRING(__ELF_WORD_SIZE)
757 "load_modmetadata: unable to load shstrtab\n");
758 err = EFTYPE;
759 goto out;
760 }
761
762 /* Find set_modmetadata_set and data sections. */
763 sh_data[0] = sh_data[1] = sh_meta = NULL;
764 for (i = 0, j = 0; i < ef.ehdr->e_shnum; i++) {
765 if (strcmp(&shstrtab[shdr[i].sh_name],
766 "set_modmetadata_set") == 0) {
767 sh_meta = &shdr[i];
768 }
769 if ((strcmp(&shstrtab[shdr[i].sh_name], ".data") == 0) ||
770 (strcmp(&shstrtab[shdr[i].sh_name], ".rodata") == 0)) {
771 sh_data[j++] = &shdr[i];
772 }
773 }
774 if (sh_meta == NULL || sh_data[0] == NULL || sh_data[1] == NULL) {
775 printf("\nelf" __XSTRING(__ELF_WORD_SIZE)
776 "load_modmetadata: unable to find set_modmetadata_set or data sections\n");
777 err = EFTYPE;
778 goto out;
779 }
780
781 /* Load set_modmetadata_set into memory */
782 err = kern_pread(ef.fd, dest, sh_meta->sh_size, sh_meta->sh_offset);
783 if (err != 0) {
784 printf("\nelf" __XSTRING(__ELF_WORD_SIZE)
785 "load_modmetadata: unable to load set_modmetadata_set: %d\n", err);
786 goto out;
787 }
788 p_start = dest;
789 p_end = dest + sh_meta->sh_size;
790 dest += sh_meta->sh_size;
791
792 /* Load data sections into memory. */
793 err = kern_pread(ef.fd, dest, sh_data[0]->sh_size,
794 sh_data[0]->sh_offset);
795 if (err != 0) {
796 printf("\nelf" __XSTRING(__ELF_WORD_SIZE)
797 "load_modmetadata: unable to load data: %d\n", err);
798 goto out;
799 }
800
801 /*
802 * We have to increment the dest, so that the offset is the same into
803 * both the .rodata and .data sections.
804 */
805 ef.off = -(sh_data[0]->sh_addr - dest);
806 dest += (sh_data[1]->sh_addr - sh_data[0]->sh_addr);
807
808 err = kern_pread(ef.fd, dest, sh_data[1]->sh_size,
809 sh_data[1]->sh_offset);
810 if (err != 0) {
811 printf("\nelf" __XSTRING(__ELF_WORD_SIZE)
812 "load_modmetadata: unable to load data: %d\n", err);
813 goto out;
814 }
815
816 err = __elfN(parse_modmetadata)(fp, &ef, p_start, p_end);
817 if (err != 0) {
818 printf("\nelf" __XSTRING(__ELF_WORD_SIZE)
819 "load_modmetadata: unable to parse metadata: %d\n", err);
820 goto out;
821 }
822
823 out:
824 if (shstrtab != NULL)
825 free(shstrtab);
826 if (shdr != NULL)
827 free(shdr);
828 if (ef.firstpage != NULL)
829 free(ef.firstpage);
830 if (ef.fd != -1)
831 close(ef.fd);
832 return (err);
833 }
834
835 int
__elfN(parse_modmetadata)836 __elfN(parse_modmetadata)(struct preloaded_file *fp, elf_file_t ef,
837 Elf_Addr p_start, Elf_Addr p_end)
838 {
839 struct mod_metadata md;
840 #if (defined(__i386__) || defined(__powerpc__)) && __ELF_WORD_SIZE == 64
841 struct mod_metadata64 md64;
842 #elif defined(__amd64__) && __ELF_WORD_SIZE == 32
843 struct mod_metadata32 md32;
844 #endif
845 struct mod_depend *mdepend;
846 struct mod_version mver;
847 char *s;
848 int error, modcnt, minfolen;
849 Elf_Addr v, p;
850
851 modcnt = 0;
852 p = p_start;
853 while (p < p_end) {
854 COPYOUT(p, &v, sizeof(v));
855 error = __elfN(reloc_ptr)(fp, ef, p, &v, sizeof(v));
856 if (error == EOPNOTSUPP)
857 v += ef->off;
858 else if (error != 0)
859 return (error);
860 #if (defined(__i386__) || defined(__powerpc__)) && __ELF_WORD_SIZE == 64
861 COPYOUT(v, &md64, sizeof(md64));
862 error = __elfN(reloc_ptr)(fp, ef, v, &md64, sizeof(md64));
863 if (error == EOPNOTSUPP) {
864 md64.md_cval += ef->off;
865 md64.md_data += ef->off;
866 } else if (error != 0)
867 return (error);
868 md.md_version = md64.md_version;
869 md.md_type = md64.md_type;
870 md.md_cval = (const char *)(uintptr_t)md64.md_cval;
871 md.md_data = (void *)(uintptr_t)md64.md_data;
872 #elif defined(__amd64__) && __ELF_WORD_SIZE == 32
873 COPYOUT(v, &md32, sizeof(md32));
874 error = __elfN(reloc_ptr)(fp, ef, v, &md32, sizeof(md32));
875 if (error == EOPNOTSUPP) {
876 md32.md_cval += ef->off;
877 md32.md_data += ef->off;
878 } else if (error != 0)
879 return (error);
880 md.md_version = md32.md_version;
881 md.md_type = md32.md_type;
882 md.md_cval = (const char *)(uintptr_t)md32.md_cval;
883 md.md_data = (void *)(uintptr_t)md32.md_data;
884 #else
885 COPYOUT(v, &md, sizeof(md));
886 error = __elfN(reloc_ptr)(fp, ef, v, &md, sizeof(md));
887 if (error == EOPNOTSUPP) {
888 md.md_cval += ef->off;
889 md.md_data += ef->off;
890 } else if (error != 0)
891 return (error);
892 #endif
893 p += sizeof(Elf_Addr);
894 switch(md.md_type) {
895 case MDT_DEPEND:
896 if (ef->kernel) /* kernel must not depend on anything */
897 break;
898 s = strdupout((vm_offset_t)md.md_cval);
899 minfolen = sizeof(*mdepend) + strlen(s) + 1;
900 mdepend = malloc(minfolen);
901 if (mdepend == NULL)
902 return ENOMEM;
903 COPYOUT((vm_offset_t)md.md_data, mdepend, sizeof(*mdepend));
904 strcpy((char*)(mdepend + 1), s);
905 free(s);
906 file_addmetadata(fp, MODINFOMD_DEPLIST, minfolen, mdepend);
907 free(mdepend);
908 break;
909 case MDT_VERSION:
910 s = strdupout((vm_offset_t)md.md_cval);
911 COPYOUT((vm_offset_t)md.md_data, &mver, sizeof(mver));
912 file_addmodule(fp, s, mver.mv_version, NULL);
913 free(s);
914 modcnt++;
915 break;
916 }
917 }
918 if (modcnt == 0) {
919 s = fake_modname(fp->f_name);
920 file_addmodule(fp, s, 1, NULL);
921 free(s);
922 }
923 return 0;
924 }
925
926 static unsigned long
elf_hash(const char * name)927 elf_hash(const char *name)
928 {
929 const unsigned char *p = (const unsigned char *) name;
930 unsigned long h = 0;
931 unsigned long g;
932
933 while (*p != '\0') {
934 h = (h << 4) + *p++;
935 if ((g = h & 0xf0000000) != 0)
936 h ^= g >> 24;
937 h &= ~g;
938 }
939 return h;
940 }
941
942 static const char __elfN(bad_symtable)[] = "elf" __XSTRING(__ELF_WORD_SIZE) "_lookup_symbol: corrupt symbol table\n";
943 int
__elfN(lookup_symbol)944 __elfN(lookup_symbol)(struct preloaded_file *fp, elf_file_t ef, const char* name,
945 Elf_Sym *symp)
946 {
947 Elf_Hashelt symnum;
948 Elf_Sym sym;
949 char *strp;
950 unsigned long hash;
951
952 hash = elf_hash(name);
953 COPYOUT(&ef->buckets[hash % ef->nbuckets], &symnum, sizeof(symnum));
954
955 while (symnum != STN_UNDEF) {
956 if (symnum >= ef->nchains) {
957 printf(__elfN(bad_symtable));
958 return ENOENT;
959 }
960
961 COPYOUT(ef->symtab + symnum, &sym, sizeof(sym));
962 if (sym.st_name == 0) {
963 printf(__elfN(bad_symtable));
964 return ENOENT;
965 }
966
967 strp = strdupout((vm_offset_t)(ef->strtab + sym.st_name));
968 if (strcmp(name, strp) == 0) {
969 free(strp);
970 if (sym.st_shndx != SHN_UNDEF ||
971 (sym.st_value != 0 &&
972 ELF_ST_TYPE(sym.st_info) == STT_FUNC)) {
973 *symp = sym;
974 return 0;
975 }
976 return ENOENT;
977 }
978 free(strp);
979 COPYOUT(&ef->chains[symnum], &symnum, sizeof(symnum));
980 }
981 return ENOENT;
982 }
983
984 /*
985 * Apply any intra-module relocations to the value. p is the load address
986 * of the value and val/len is the value to be modified. This does NOT modify
987 * the image in-place, because this is done by kern_linker later on.
988 *
989 * Returns EOPNOTSUPP if no relocation method is supplied.
990 */
991 static int
__elfN(reloc_ptr)992 __elfN(reloc_ptr)(struct preloaded_file *mp, elf_file_t ef,
993 Elf_Addr p, void *val, size_t len)
994 {
995 size_t n;
996 Elf_Rela a;
997 Elf_Rel r;
998 int error;
999
1000 /*
1001 * The kernel is already relocated, but we still want to apply
1002 * offset adjustments.
1003 */
1004 if (ef->kernel)
1005 return (EOPNOTSUPP);
1006
1007 for (n = 0; n < ef->relsz / sizeof(r); n++) {
1008 COPYOUT(ef->rel + n, &r, sizeof(r));
1009
1010 error = __elfN(reloc)(ef, __elfN(symaddr), &r, ELF_RELOC_REL,
1011 ef->off, p, val, len);
1012 if (error != 0)
1013 return (error);
1014 }
1015 for (n = 0; n < ef->relasz / sizeof(a); n++) {
1016 COPYOUT(ef->rela + n, &a, sizeof(a));
1017
1018 error = __elfN(reloc)(ef, __elfN(symaddr), &a, ELF_RELOC_RELA,
1019 ef->off, p, val, len);
1020 if (error != 0)
1021 return (error);
1022 }
1023
1024 return (0);
1025 }
1026
1027 static Elf_Addr
__elfN(symaddr)1028 __elfN(symaddr)(struct elf_file *ef, Elf_Size symidx)
1029 {
1030
1031 /* Symbol lookup by index not required here. */
1032 return (0);
1033 }
1034