FreeBSD/Linux Kernel Cross Reference
sys/kern/imgact_elf.c
1 /*-
2 * Copyright (c) 2000 David O'Brien
3 * Copyright (c) 1995-1996 Søren Schmidt
4 * Copyright (c) 1996 Peter Wemm
5 * All rights reserved.
6 *
7 * Redistribution and use in source and binary forms, with or without
8 * modification, are permitted provided that the following conditions
9 * are met:
10 * 1. Redistributions of source code must retain the above copyright
11 * notice, this list of conditions and the following disclaimer
12 * in this position and unchanged.
13 * 2. Redistributions in binary form must reproduce the above copyright
14 * notice, this list of conditions and the following disclaimer in the
15 * documentation and/or other materials provided with the distribution.
16 * 3. The name of the author may not be used to endorse or promote products
17 * derived from this software without specific prior written permission
18 *
19 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
20 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
21 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
22 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
23 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
24 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
25 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
26 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
27 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
28 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
29 */
30
31 #include <sys/cdefs.h>
32 __FBSDID("$FreeBSD: head/sys/kern/imgact_elf.c 232828 2012-03-11 19:38:49Z kib $");
33
34 #include "opt_capsicum.h"
35 #include "opt_compat.h"
36 #include "opt_core.h"
37
38 #include <sys/param.h>
39 #include <sys/capability.h>
40 #include <sys/exec.h>
41 #include <sys/fcntl.h>
42 #include <sys/imgact.h>
43 #include <sys/imgact_elf.h>
44 #include <sys/kernel.h>
45 #include <sys/lock.h>
46 #include <sys/malloc.h>
47 #include <sys/mount.h>
48 #include <sys/mutex.h>
49 #include <sys/mman.h>
50 #include <sys/namei.h>
51 #include <sys/pioctl.h>
52 #include <sys/proc.h>
53 #include <sys/procfs.h>
54 #include <sys/racct.h>
55 #include <sys/resourcevar.h>
56 #include <sys/sf_buf.h>
57 #include <sys/smp.h>
58 #include <sys/systm.h>
59 #include <sys/signalvar.h>
60 #include <sys/stat.h>
61 #include <sys/sx.h>
62 #include <sys/syscall.h>
63 #include <sys/sysctl.h>
64 #include <sys/sysent.h>
65 #include <sys/vnode.h>
66 #include <sys/syslog.h>
67 #include <sys/eventhandler.h>
68
69 #include <net/zlib.h>
70
71 #include <vm/vm.h>
72 #include <vm/vm_kern.h>
73 #include <vm/vm_param.h>
74 #include <vm/pmap.h>
75 #include <vm/vm_map.h>
76 #include <vm/vm_object.h>
77 #include <vm/vm_extern.h>
78
79 #include <machine/elf.h>
80 #include <machine/md_var.h>
81
82 #define OLD_EI_BRAND 8
83
84 static int __elfN(check_header)(const Elf_Ehdr *hdr);
85 static Elf_Brandinfo *__elfN(get_brandinfo)(struct image_params *imgp,
86 const char *interp, int32_t *osrel);
87 static int __elfN(load_file)(struct proc *p, const char *file, u_long *addr,
88 u_long *entry, size_t pagesize);
89 static int __elfN(load_section)(struct image_params *imgp, vm_offset_t offset,
90 caddr_t vmaddr, size_t memsz, size_t filsz, vm_prot_t prot,
91 size_t pagesize);
92 static int __CONCAT(exec_, __elfN(imgact))(struct image_params *imgp);
93 static boolean_t __elfN(freebsd_trans_osrel)(const Elf_Note *note,
94 int32_t *osrel);
95 static boolean_t kfreebsd_trans_osrel(const Elf_Note *note, int32_t *osrel);
96 static boolean_t __elfN(check_note)(struct image_params *imgp,
97 Elf_Brandnote *checknote, int32_t *osrel);
98 static vm_prot_t __elfN(trans_prot)(Elf_Word);
99 static Elf_Word __elfN(untrans_prot)(vm_prot_t);
100
101 SYSCTL_NODE(_kern, OID_AUTO, __CONCAT(elf, __ELF_WORD_SIZE), CTLFLAG_RW, 0,
102 "");
103
104 #ifdef COMPRESS_USER_CORES
105 static int compress_core(gzFile, char *, char *, unsigned int,
106 struct thread * td);
107 #define CORE_BUF_SIZE (16 * 1024)
108 #endif
109
110 int __elfN(fallback_brand) = -1;
111 SYSCTL_INT(__CONCAT(_kern_elf, __ELF_WORD_SIZE), OID_AUTO,
112 fallback_brand, CTLFLAG_RW, &__elfN(fallback_brand), 0,
113 __XSTRING(__CONCAT(ELF, __ELF_WORD_SIZE)) " brand of last resort");
114 TUNABLE_INT("kern.elf" __XSTRING(__ELF_WORD_SIZE) ".fallback_brand",
115 &__elfN(fallback_brand));
116
117 static int elf_legacy_coredump = 0;
118 SYSCTL_INT(_debug, OID_AUTO, __elfN(legacy_coredump), CTLFLAG_RW,
119 &elf_legacy_coredump, 0, "");
120
121 int __elfN(nxstack) =
122 #if defined(__amd64__) || defined(__powerpc64__) /* both 64 and 32 bit */
123 1;
124 #else
125 0;
126 #endif
127 SYSCTL_INT(__CONCAT(_kern_elf, __ELF_WORD_SIZE), OID_AUTO,
128 nxstack, CTLFLAG_RW, &__elfN(nxstack), 0,
129 __XSTRING(__CONCAT(ELF, __ELF_WORD_SIZE)) ": enable non-executable stack");
130
131 #if __ELF_WORD_SIZE == 32
132 #if defined(__amd64__) || defined(__ia64__)
133 int i386_read_exec = 0;
134 SYSCTL_INT(_kern_elf32, OID_AUTO, read_exec, CTLFLAG_RW, &i386_read_exec, 0,
135 "enable execution from readable segments");
136 #endif
137 #endif
138
139 static Elf_Brandinfo *elf_brand_list[MAX_BRANDS];
140
141 #define trunc_page_ps(va, ps) ((va) & ~(ps - 1))
142 #define round_page_ps(va, ps) (((va) + (ps - 1)) & ~(ps - 1))
143 #define aligned(a, t) (trunc_page_ps((u_long)(a), sizeof(t)) == (u_long)(a))
144
145 static const char FREEBSD_ABI_VENDOR[] = "FreeBSD";
146
147 Elf_Brandnote __elfN(freebsd_brandnote) = {
148 .hdr.n_namesz = sizeof(FREEBSD_ABI_VENDOR),
149 .hdr.n_descsz = sizeof(int32_t),
150 .hdr.n_type = 1,
151 .vendor = FREEBSD_ABI_VENDOR,
152 .flags = BN_TRANSLATE_OSREL,
153 .trans_osrel = __elfN(freebsd_trans_osrel)
154 };
155
156 static boolean_t
157 __elfN(freebsd_trans_osrel)(const Elf_Note *note, int32_t *osrel)
158 {
159 uintptr_t p;
160
161 p = (uintptr_t)(note + 1);
162 p += roundup2(note->n_namesz, sizeof(Elf32_Addr));
163 *osrel = *(const int32_t *)(p);
164
165 return (TRUE);
166 }
167
168 static const char GNU_ABI_VENDOR[] = "GNU";
169 static int GNU_KFREEBSD_ABI_DESC = 3;
170
171 Elf_Brandnote __elfN(kfreebsd_brandnote) = {
172 .hdr.n_namesz = sizeof(GNU_ABI_VENDOR),
173 .hdr.n_descsz = 16, /* XXX at least 16 */
174 .hdr.n_type = 1,
175 .vendor = GNU_ABI_VENDOR,
176 .flags = BN_TRANSLATE_OSREL,
177 .trans_osrel = kfreebsd_trans_osrel
178 };
179
180 static boolean_t
181 kfreebsd_trans_osrel(const Elf_Note *note, int32_t *osrel)
182 {
183 const Elf32_Word *desc;
184 uintptr_t p;
185
186 p = (uintptr_t)(note + 1);
187 p += roundup2(note->n_namesz, sizeof(Elf32_Addr));
188
189 desc = (const Elf32_Word *)p;
190 if (desc[0] != GNU_KFREEBSD_ABI_DESC)
191 return (FALSE);
192
193 /*
194 * Debian GNU/kFreeBSD embed the earliest compatible kernel version
195 * (__FreeBSD_version: <major><two digit minor>Rxx) in the LSB way.
196 */
197 *osrel = desc[1] * 100000 + desc[2] * 1000 + desc[3];
198
199 return (TRUE);
200 }
201
202 int
203 __elfN(insert_brand_entry)(Elf_Brandinfo *entry)
204 {
205 int i;
206
207 for (i = 0; i < MAX_BRANDS; i++) {
208 if (elf_brand_list[i] == NULL) {
209 elf_brand_list[i] = entry;
210 break;
211 }
212 }
213 if (i == MAX_BRANDS) {
214 printf("WARNING: %s: could not insert brandinfo entry: %p\n",
215 __func__, entry);
216 return (-1);
217 }
218 return (0);
219 }
220
221 int
222 __elfN(remove_brand_entry)(Elf_Brandinfo *entry)
223 {
224 int i;
225
226 for (i = 0; i < MAX_BRANDS; i++) {
227 if (elf_brand_list[i] == entry) {
228 elf_brand_list[i] = NULL;
229 break;
230 }
231 }
232 if (i == MAX_BRANDS)
233 return (-1);
234 return (0);
235 }
236
237 int
238 __elfN(brand_inuse)(Elf_Brandinfo *entry)
239 {
240 struct proc *p;
241 int rval = FALSE;
242
243 sx_slock(&allproc_lock);
244 FOREACH_PROC_IN_SYSTEM(p) {
245 if (p->p_sysent == entry->sysvec) {
246 rval = TRUE;
247 break;
248 }
249 }
250 sx_sunlock(&allproc_lock);
251
252 return (rval);
253 }
254
255 static Elf_Brandinfo *
256 __elfN(get_brandinfo)(struct image_params *imgp, const char *interp,
257 int32_t *osrel)
258 {
259 const Elf_Ehdr *hdr = (const Elf_Ehdr *)imgp->image_header;
260 Elf_Brandinfo *bi;
261 boolean_t ret;
262 int i;
263
264 /*
265 * We support four types of branding -- (1) the ELF EI_OSABI field
266 * that SCO added to the ELF spec, (2) FreeBSD 3.x's traditional string
267 * branding w/in the ELF header, (3) path of the `interp_path'
268 * field, and (4) the ".note.ABI-tag" ELF section.
269 */
270
271 /* Look for an ".note.ABI-tag" ELF section */
272 for (i = 0; i < MAX_BRANDS; i++) {
273 bi = elf_brand_list[i];
274 if (bi == NULL)
275 continue;
276 if (hdr->e_machine == bi->machine && (bi->flags &
277 (BI_BRAND_NOTE|BI_BRAND_NOTE_MANDATORY)) != 0) {
278 ret = __elfN(check_note)(imgp, bi->brand_note, osrel);
279 if (ret)
280 return (bi);
281 }
282 }
283
284 /* If the executable has a brand, search for it in the brand list. */
285 for (i = 0; i < MAX_BRANDS; i++) {
286 bi = elf_brand_list[i];
287 if (bi == NULL || bi->flags & BI_BRAND_NOTE_MANDATORY)
288 continue;
289 if (hdr->e_machine == bi->machine &&
290 (hdr->e_ident[EI_OSABI] == bi->brand ||
291 strncmp((const char *)&hdr->e_ident[OLD_EI_BRAND],
292 bi->compat_3_brand, strlen(bi->compat_3_brand)) == 0))
293 return (bi);
294 }
295
296 /* Lacking a known brand, search for a recognized interpreter. */
297 if (interp != NULL) {
298 for (i = 0; i < MAX_BRANDS; i++) {
299 bi = elf_brand_list[i];
300 if (bi == NULL || bi->flags & BI_BRAND_NOTE_MANDATORY)
301 continue;
302 if (hdr->e_machine == bi->machine &&
303 strcmp(interp, bi->interp_path) == 0)
304 return (bi);
305 }
306 }
307
308 /* Lacking a recognized interpreter, try the default brand */
309 for (i = 0; i < MAX_BRANDS; i++) {
310 bi = elf_brand_list[i];
311 if (bi == NULL || bi->flags & BI_BRAND_NOTE_MANDATORY)
312 continue;
313 if (hdr->e_machine == bi->machine &&
314 __elfN(fallback_brand) == bi->brand)
315 return (bi);
316 }
317 return (NULL);
318 }
319
320 static int
321 __elfN(check_header)(const Elf_Ehdr *hdr)
322 {
323 Elf_Brandinfo *bi;
324 int i;
325
326 if (!IS_ELF(*hdr) ||
327 hdr->e_ident[EI_CLASS] != ELF_TARG_CLASS ||
328 hdr->e_ident[EI_DATA] != ELF_TARG_DATA ||
329 hdr->e_ident[EI_VERSION] != EV_CURRENT ||
330 hdr->e_phentsize != sizeof(Elf_Phdr) ||
331 hdr->e_version != ELF_TARG_VER)
332 return (ENOEXEC);
333
334 /*
335 * Make sure we have at least one brand for this machine.
336 */
337
338 for (i = 0; i < MAX_BRANDS; i++) {
339 bi = elf_brand_list[i];
340 if (bi != NULL && bi->machine == hdr->e_machine)
341 break;
342 }
343 if (i == MAX_BRANDS)
344 return (ENOEXEC);
345
346 return (0);
347 }
348
349 static int
350 __elfN(map_partial)(vm_map_t map, vm_object_t object, vm_ooffset_t offset,
351 vm_offset_t start, vm_offset_t end, vm_prot_t prot)
352 {
353 struct sf_buf *sf;
354 int error;
355 vm_offset_t off;
356
357 /*
358 * Create the page if it doesn't exist yet. Ignore errors.
359 */
360 vm_map_lock(map);
361 vm_map_insert(map, NULL, 0, trunc_page(start), round_page(end),
362 VM_PROT_ALL, VM_PROT_ALL, 0);
363 vm_map_unlock(map);
364
365 /*
366 * Find the page from the underlying object.
367 */
368 if (object) {
369 sf = vm_imgact_map_page(object, offset);
370 if (sf == NULL)
371 return (KERN_FAILURE);
372 off = offset - trunc_page(offset);
373 error = copyout((caddr_t)sf_buf_kva(sf) + off, (caddr_t)start,
374 end - start);
375 vm_imgact_unmap_page(sf);
376 if (error) {
377 return (KERN_FAILURE);
378 }
379 }
380
381 return (KERN_SUCCESS);
382 }
383
384 static int
385 __elfN(map_insert)(vm_map_t map, vm_object_t object, vm_ooffset_t offset,
386 vm_offset_t start, vm_offset_t end, vm_prot_t prot, int cow)
387 {
388 struct sf_buf *sf;
389 vm_offset_t off;
390 vm_size_t sz;
391 int error, rv;
392
393 if (start != trunc_page(start)) {
394 rv = __elfN(map_partial)(map, object, offset, start,
395 round_page(start), prot);
396 if (rv)
397 return (rv);
398 offset += round_page(start) - start;
399 start = round_page(start);
400 }
401 if (end != round_page(end)) {
402 rv = __elfN(map_partial)(map, object, offset +
403 trunc_page(end) - start, trunc_page(end), end, prot);
404 if (rv)
405 return (rv);
406 end = trunc_page(end);
407 }
408 if (end > start) {
409 if (offset & PAGE_MASK) {
410 /*
411 * The mapping is not page aligned. This means we have
412 * to copy the data. Sigh.
413 */
414 rv = vm_map_find(map, NULL, 0, &start, end - start,
415 FALSE, prot | VM_PROT_WRITE, VM_PROT_ALL, 0);
416 if (rv)
417 return (rv);
418 if (object == NULL)
419 return (KERN_SUCCESS);
420 for (; start < end; start += sz) {
421 sf = vm_imgact_map_page(object, offset);
422 if (sf == NULL)
423 return (KERN_FAILURE);
424 off = offset - trunc_page(offset);
425 sz = end - start;
426 if (sz > PAGE_SIZE - off)
427 sz = PAGE_SIZE - off;
428 error = copyout((caddr_t)sf_buf_kva(sf) + off,
429 (caddr_t)start, sz);
430 vm_imgact_unmap_page(sf);
431 if (error) {
432 return (KERN_FAILURE);
433 }
434 offset += sz;
435 }
436 rv = KERN_SUCCESS;
437 } else {
438 vm_object_reference(object);
439 vm_map_lock(map);
440 rv = vm_map_insert(map, object, offset, start, end,
441 prot, VM_PROT_ALL, cow);
442 vm_map_unlock(map);
443 if (rv != KERN_SUCCESS)
444 vm_object_deallocate(object);
445 }
446 return (rv);
447 } else {
448 return (KERN_SUCCESS);
449 }
450 }
451
452 static int
453 __elfN(load_section)(struct image_params *imgp, vm_offset_t offset,
454 caddr_t vmaddr, size_t memsz, size_t filsz, vm_prot_t prot,
455 size_t pagesize)
456 {
457 struct sf_buf *sf;
458 size_t map_len;
459 vm_map_t map;
460 vm_object_t object;
461 vm_offset_t map_addr;
462 int error, rv, cow;
463 size_t copy_len;
464 vm_offset_t file_addr;
465
466 /*
467 * It's necessary to fail if the filsz + offset taken from the
468 * header is greater than the actual file pager object's size.
469 * If we were to allow this, then the vm_map_find() below would
470 * walk right off the end of the file object and into the ether.
471 *
472 * While I'm here, might as well check for something else that
473 * is invalid: filsz cannot be greater than memsz.
474 */
475 if ((off_t)filsz + offset > imgp->attr->va_size || filsz > memsz) {
476 uprintf("elf_load_section: truncated ELF file\n");
477 return (ENOEXEC);
478 }
479
480 object = imgp->object;
481 map = &imgp->proc->p_vmspace->vm_map;
482 map_addr = trunc_page_ps((vm_offset_t)vmaddr, pagesize);
483 file_addr = trunc_page_ps(offset, pagesize);
484
485 /*
486 * We have two choices. We can either clear the data in the last page
487 * of an oversized mapping, or we can start the anon mapping a page
488 * early and copy the initialized data into that first page. We
489 * choose the second..
490 */
491 if (memsz > filsz)
492 map_len = trunc_page_ps(offset + filsz, pagesize) - file_addr;
493 else
494 map_len = round_page_ps(offset + filsz, pagesize) - file_addr;
495
496 if (map_len != 0) {
497 /* cow flags: don't dump readonly sections in core */
498 cow = MAP_COPY_ON_WRITE | MAP_PREFAULT |
499 (prot & VM_PROT_WRITE ? 0 : MAP_DISABLE_COREDUMP);
500
501 rv = __elfN(map_insert)(map,
502 object,
503 file_addr, /* file offset */
504 map_addr, /* virtual start */
505 map_addr + map_len,/* virtual end */
506 prot,
507 cow);
508 if (rv != KERN_SUCCESS)
509 return (EINVAL);
510
511 /* we can stop now if we've covered it all */
512 if (memsz == filsz) {
513 return (0);
514 }
515 }
516
517
518 /*
519 * We have to get the remaining bit of the file into the first part
520 * of the oversized map segment. This is normally because the .data
521 * segment in the file is extended to provide bss. It's a neat idea
522 * to try and save a page, but it's a pain in the behind to implement.
523 */
524 copy_len = (offset + filsz) - trunc_page_ps(offset + filsz, pagesize);
525 map_addr = trunc_page_ps((vm_offset_t)vmaddr + filsz, pagesize);
526 map_len = round_page_ps((vm_offset_t)vmaddr + memsz, pagesize) -
527 map_addr;
528
529 /* This had damn well better be true! */
530 if (map_len != 0) {
531 rv = __elfN(map_insert)(map, NULL, 0, map_addr, map_addr +
532 map_len, VM_PROT_ALL, 0);
533 if (rv != KERN_SUCCESS) {
534 return (EINVAL);
535 }
536 }
537
538 if (copy_len != 0) {
539 vm_offset_t off;
540
541 sf = vm_imgact_map_page(object, offset + filsz);
542 if (sf == NULL)
543 return (EIO);
544
545 /* send the page fragment to user space */
546 off = trunc_page_ps(offset + filsz, pagesize) -
547 trunc_page(offset + filsz);
548 error = copyout((caddr_t)sf_buf_kva(sf) + off,
549 (caddr_t)map_addr, copy_len);
550 vm_imgact_unmap_page(sf);
551 if (error) {
552 return (error);
553 }
554 }
555
556 /*
557 * set it to the specified protection.
558 * XXX had better undo the damage from pasting over the cracks here!
559 */
560 vm_map_protect(map, trunc_page(map_addr), round_page(map_addr +
561 map_len), prot, FALSE);
562
563 return (0);
564 }
565
566 /*
567 * Load the file "file" into memory. It may be either a shared object
568 * or an executable.
569 *
570 * The "addr" reference parameter is in/out. On entry, it specifies
571 * the address where a shared object should be loaded. If the file is
572 * an executable, this value is ignored. On exit, "addr" specifies
573 * where the file was actually loaded.
574 *
575 * The "entry" reference parameter is out only. On exit, it specifies
576 * the entry point for the loaded file.
577 */
578 static int
579 __elfN(load_file)(struct proc *p, const char *file, u_long *addr,
580 u_long *entry, size_t pagesize)
581 {
582 struct {
583 struct nameidata nd;
584 struct vattr attr;
585 struct image_params image_params;
586 } *tempdata;
587 const Elf_Ehdr *hdr = NULL;
588 const Elf_Phdr *phdr = NULL;
589 struct nameidata *nd;
590 struct vattr *attr;
591 struct image_params *imgp;
592 vm_prot_t prot;
593 u_long rbase;
594 u_long base_addr = 0;
595 int vfslocked, error, i, numsegs;
596
597 #ifdef CAPABILITY_MODE
598 /*
599 * XXXJA: This check can go away once we are sufficiently confident
600 * that the checks in namei() are correct.
601 */
602 if (IN_CAPABILITY_MODE(curthread))
603 return (ECAPMODE);
604 #endif
605
606 tempdata = malloc(sizeof(*tempdata), M_TEMP, M_WAITOK);
607 nd = &tempdata->nd;
608 attr = &tempdata->attr;
609 imgp = &tempdata->image_params;
610
611 /*
612 * Initialize part of the common data
613 */
614 imgp->proc = p;
615 imgp->attr = attr;
616 imgp->firstpage = NULL;
617 imgp->image_header = NULL;
618 imgp->object = NULL;
619 imgp->execlabel = NULL;
620
621 NDINIT(nd, LOOKUP, MPSAFE|LOCKLEAF|FOLLOW, UIO_SYSSPACE, file,
622 curthread);
623 vfslocked = 0;
624 if ((error = namei(nd)) != 0) {
625 nd->ni_vp = NULL;
626 goto fail;
627 }
628 vfslocked = NDHASGIANT(nd);
629 NDFREE(nd, NDF_ONLY_PNBUF);
630 imgp->vp = nd->ni_vp;
631
632 /*
633 * Check permissions, modes, uid, etc on the file, and "open" it.
634 */
635 error = exec_check_permissions(imgp);
636 if (error)
637 goto fail;
638
639 error = exec_map_first_page(imgp);
640 if (error)
641 goto fail;
642
643 /*
644 * Also make certain that the interpreter stays the same, so set
645 * its VV_TEXT flag, too.
646 */
647 nd->ni_vp->v_vflag |= VV_TEXT;
648
649 imgp->object = nd->ni_vp->v_object;
650
651 hdr = (const Elf_Ehdr *)imgp->image_header;
652 if ((error = __elfN(check_header)(hdr)) != 0)
653 goto fail;
654 if (hdr->e_type == ET_DYN)
655 rbase = *addr;
656 else if (hdr->e_type == ET_EXEC)
657 rbase = 0;
658 else {
659 error = ENOEXEC;
660 goto fail;
661 }
662
663 /* Only support headers that fit within first page for now */
664 /* (multiplication of two Elf_Half fields will not overflow) */
665 if ((hdr->e_phoff > PAGE_SIZE) ||
666 (hdr->e_phentsize * hdr->e_phnum) > PAGE_SIZE - hdr->e_phoff) {
667 error = ENOEXEC;
668 goto fail;
669 }
670
671 phdr = (const Elf_Phdr *)(imgp->image_header + hdr->e_phoff);
672 if (!aligned(phdr, Elf_Addr)) {
673 error = ENOEXEC;
674 goto fail;
675 }
676
677 for (i = 0, numsegs = 0; i < hdr->e_phnum; i++) {
678 if (phdr[i].p_type == PT_LOAD && phdr[i].p_memsz != 0) {
679 /* Loadable segment */
680 prot = __elfN(trans_prot)(phdr[i].p_flags);
681 error = __elfN(load_section)(imgp, phdr[i].p_offset,
682 (caddr_t)(uintptr_t)phdr[i].p_vaddr + rbase,
683 phdr[i].p_memsz, phdr[i].p_filesz, prot, pagesize);
684 if (error != 0)
685 goto fail;
686 /*
687 * Establish the base address if this is the
688 * first segment.
689 */
690 if (numsegs == 0)
691 base_addr = trunc_page(phdr[i].p_vaddr +
692 rbase);
693 numsegs++;
694 }
695 }
696 *addr = base_addr;
697 *entry = (unsigned long)hdr->e_entry + rbase;
698
699 fail:
700 if (imgp->firstpage)
701 exec_unmap_first_page(imgp);
702
703 if (nd->ni_vp)
704 vput(nd->ni_vp);
705
706 VFS_UNLOCK_GIANT(vfslocked);
707 free(tempdata, M_TEMP);
708
709 return (error);
710 }
711
712 static int
713 __CONCAT(exec_, __elfN(imgact))(struct image_params *imgp)
714 {
715 const Elf_Ehdr *hdr = (const Elf_Ehdr *)imgp->image_header;
716 const Elf_Phdr *phdr;
717 Elf_Auxargs *elf_auxargs;
718 struct vmspace *vmspace;
719 vm_prot_t prot;
720 u_long text_size = 0, data_size = 0, total_size = 0;
721 u_long text_addr = 0, data_addr = 0;
722 u_long seg_size, seg_addr;
723 u_long addr, baddr, et_dyn_addr, entry = 0, proghdr = 0;
724 int32_t osrel = 0;
725 int error = 0, i, n;
726 const char *interp = NULL, *newinterp = NULL;
727 Elf_Brandinfo *brand_info;
728 char *path;
729 struct sysentvec *sv;
730
731 /*
732 * Do we have a valid ELF header ?
733 *
734 * Only allow ET_EXEC & ET_DYN here, reject ET_DYN later
735 * if particular brand doesn't support it.
736 */
737 if (__elfN(check_header)(hdr) != 0 ||
738 (hdr->e_type != ET_EXEC && hdr->e_type != ET_DYN))
739 return (-1);
740
741 /*
742 * From here on down, we return an errno, not -1, as we've
743 * detected an ELF file.
744 */
745
746 if ((hdr->e_phoff > PAGE_SIZE) ||
747 (hdr->e_phoff + hdr->e_phentsize * hdr->e_phnum) > PAGE_SIZE) {
748 /* Only support headers in first page for now */
749 return (ENOEXEC);
750 }
751 phdr = (const Elf_Phdr *)(imgp->image_header + hdr->e_phoff);
752 if (!aligned(phdr, Elf_Addr))
753 return (ENOEXEC);
754 n = 0;
755 baddr = 0;
756 for (i = 0; i < hdr->e_phnum; i++) {
757 switch (phdr[i].p_type) {
758 case PT_LOAD:
759 if (n == 0)
760 baddr = phdr[i].p_vaddr;
761 n++;
762 break;
763 case PT_INTERP:
764 /* Path to interpreter */
765 if (phdr[i].p_filesz > MAXPATHLEN ||
766 phdr[i].p_offset + phdr[i].p_filesz > PAGE_SIZE)
767 return (ENOEXEC);
768 interp = imgp->image_header + phdr[i].p_offset;
769 break;
770 case PT_GNU_STACK:
771 if (__elfN(nxstack))
772 imgp->stack_prot =
773 __elfN(trans_prot)(phdr[i].p_flags);
774 break;
775 }
776 }
777
778 brand_info = __elfN(get_brandinfo)(imgp, interp, &osrel);
779 if (brand_info == NULL) {
780 uprintf("ELF binary type \"%u\" not known.\n",
781 hdr->e_ident[EI_OSABI]);
782 return (ENOEXEC);
783 }
784 if (hdr->e_type == ET_DYN) {
785 if ((brand_info->flags & BI_CAN_EXEC_DYN) == 0)
786 return (ENOEXEC);
787 /*
788 * Honour the base load address from the dso if it is
789 * non-zero for some reason.
790 */
791 if (baddr == 0)
792 et_dyn_addr = ET_DYN_LOAD_ADDR;
793 else
794 et_dyn_addr = 0;
795 } else
796 et_dyn_addr = 0;
797 sv = brand_info->sysvec;
798 if (interp != NULL && brand_info->interp_newpath != NULL)
799 newinterp = brand_info->interp_newpath;
800
801 /*
802 * Avoid a possible deadlock if the current address space is destroyed
803 * and that address space maps the locked vnode. In the common case,
804 * the locked vnode's v_usecount is decremented but remains greater
805 * than zero. Consequently, the vnode lock is not needed by vrele().
806 * However, in cases where the vnode lock is external, such as nullfs,
807 * v_usecount may become zero.
808 *
809 * The VV_TEXT flag prevents modifications to the executable while
810 * the vnode is unlocked.
811 */
812 VOP_UNLOCK(imgp->vp, 0);
813
814 error = exec_new_vmspace(imgp, sv);
815 imgp->proc->p_sysent = sv;
816
817 vn_lock(imgp->vp, LK_EXCLUSIVE | LK_RETRY);
818 if (error)
819 return (error);
820
821 for (i = 0; i < hdr->e_phnum; i++) {
822 switch (phdr[i].p_type) {
823 case PT_LOAD: /* Loadable segment */
824 if (phdr[i].p_memsz == 0)
825 break;
826 prot = __elfN(trans_prot)(phdr[i].p_flags);
827
828 #if defined(__ia64__) && __ELF_WORD_SIZE == 32 && defined(IA32_ME_HARDER)
829 /*
830 * Some x86 binaries assume read == executable,
831 * notably the M3 runtime and therefore cvsup
832 */
833 if (prot & VM_PROT_READ)
834 prot |= VM_PROT_EXECUTE;
835 #endif
836
837 error = __elfN(load_section)(imgp, phdr[i].p_offset,
838 (caddr_t)(uintptr_t)phdr[i].p_vaddr + et_dyn_addr,
839 phdr[i].p_memsz, phdr[i].p_filesz, prot,
840 sv->sv_pagesize);
841 if (error != 0)
842 return (error);
843
844 /*
845 * If this segment contains the program headers,
846 * remember their virtual address for the AT_PHDR
847 * aux entry. Static binaries don't usually include
848 * a PT_PHDR entry.
849 */
850 if (phdr[i].p_offset == 0 &&
851 hdr->e_phoff + hdr->e_phnum * hdr->e_phentsize
852 <= phdr[i].p_filesz)
853 proghdr = phdr[i].p_vaddr + hdr->e_phoff +
854 et_dyn_addr;
855
856 seg_addr = trunc_page(phdr[i].p_vaddr + et_dyn_addr);
857 seg_size = round_page(phdr[i].p_memsz +
858 phdr[i].p_vaddr + et_dyn_addr - seg_addr);
859
860 /*
861 * Make the largest executable segment the official
862 * text segment and all others data.
863 *
864 * Note that obreak() assumes that data_addr +
865 * data_size == end of data load area, and the ELF
866 * file format expects segments to be sorted by
867 * address. If multiple data segments exist, the
868 * last one will be used.
869 */
870
871 if (phdr[i].p_flags & PF_X && text_size < seg_size) {
872 text_size = seg_size;
873 text_addr = seg_addr;
874 } else {
875 data_size = seg_size;
876 data_addr = seg_addr;
877 }
878 total_size += seg_size;
879 break;
880 case PT_PHDR: /* Program header table info */
881 proghdr = phdr[i].p_vaddr + et_dyn_addr;
882 break;
883 default:
884 break;
885 }
886 }
887
888 if (data_addr == 0 && data_size == 0) {
889 data_addr = text_addr;
890 data_size = text_size;
891 }
892
893 entry = (u_long)hdr->e_entry + et_dyn_addr;
894
895 /*
896 * Check limits. It should be safe to check the
897 * limits after loading the segments since we do
898 * not actually fault in all the segments pages.
899 */
900 PROC_LOCK(imgp->proc);
901 if (data_size > lim_cur(imgp->proc, RLIMIT_DATA) ||
902 text_size > maxtsiz ||
903 total_size > lim_cur(imgp->proc, RLIMIT_VMEM) ||
904 racct_set(imgp->proc, RACCT_DATA, data_size) != 0 ||
905 racct_set(imgp->proc, RACCT_VMEM, total_size) != 0) {
906 PROC_UNLOCK(imgp->proc);
907 return (ENOMEM);
908 }
909
910 vmspace = imgp->proc->p_vmspace;
911 vmspace->vm_tsize = text_size >> PAGE_SHIFT;
912 vmspace->vm_taddr = (caddr_t)(uintptr_t)text_addr;
913 vmspace->vm_dsize = data_size >> PAGE_SHIFT;
914 vmspace->vm_daddr = (caddr_t)(uintptr_t)data_addr;
915
916 /*
917 * We load the dynamic linker where a userland call
918 * to mmap(0, ...) would put it. The rationale behind this
919 * calculation is that it leaves room for the heap to grow to
920 * its maximum allowed size.
921 */
922 addr = round_page((vm_offset_t)vmspace->vm_daddr + lim_max(imgp->proc,
923 RLIMIT_DATA));
924 PROC_UNLOCK(imgp->proc);
925
926 imgp->entry_addr = entry;
927
928 if (interp != NULL) {
929 int have_interp = FALSE;
930 VOP_UNLOCK(imgp->vp, 0);
931 if (brand_info->emul_path != NULL &&
932 brand_info->emul_path[0] != '\0') {
933 path = malloc(MAXPATHLEN, M_TEMP, M_WAITOK);
934 snprintf(path, MAXPATHLEN, "%s%s",
935 brand_info->emul_path, interp);
936 error = __elfN(load_file)(imgp->proc, path, &addr,
937 &imgp->entry_addr, sv->sv_pagesize);
938 free(path, M_TEMP);
939 if (error == 0)
940 have_interp = TRUE;
941 }
942 if (!have_interp && newinterp != NULL) {
943 error = __elfN(load_file)(imgp->proc, newinterp, &addr,
944 &imgp->entry_addr, sv->sv_pagesize);
945 if (error == 0)
946 have_interp = TRUE;
947 }
948 if (!have_interp) {
949 error = __elfN(load_file)(imgp->proc, interp, &addr,
950 &imgp->entry_addr, sv->sv_pagesize);
951 }
952 vn_lock(imgp->vp, LK_EXCLUSIVE | LK_RETRY);
953 if (error != 0) {
954 uprintf("ELF interpreter %s not found\n", interp);
955 return (error);
956 }
957 } else
958 addr = et_dyn_addr;
959
960 /*
961 * Construct auxargs table (used by the fixup routine)
962 */
963 elf_auxargs = malloc(sizeof(Elf_Auxargs), M_TEMP, M_WAITOK);
964 elf_auxargs->execfd = -1;
965 elf_auxargs->phdr = proghdr;
966 elf_auxargs->phent = hdr->e_phentsize;
967 elf_auxargs->phnum = hdr->e_phnum;
968 elf_auxargs->pagesz = PAGE_SIZE;
969 elf_auxargs->base = addr;
970 elf_auxargs->flags = 0;
971 elf_auxargs->entry = entry;
972
973 imgp->auxargs = elf_auxargs;
974 imgp->interpreted = 0;
975 imgp->reloc_base = addr;
976 imgp->proc->p_osrel = osrel;
977
978 return (error);
979 }
980
981 #define suword __CONCAT(suword, __ELF_WORD_SIZE)
982
983 int
984 __elfN(freebsd_fixup)(register_t **stack_base, struct image_params *imgp)
985 {
986 Elf_Auxargs *args = (Elf_Auxargs *)imgp->auxargs;
987 Elf_Addr *base;
988 Elf_Addr *pos;
989
990 base = (Elf_Addr *)*stack_base;
991 pos = base + (imgp->args->argc + imgp->args->envc + 2);
992
993 if (args->execfd != -1)
994 AUXARGS_ENTRY(pos, AT_EXECFD, args->execfd);
995 AUXARGS_ENTRY(pos, AT_PHDR, args->phdr);
996 AUXARGS_ENTRY(pos, AT_PHENT, args->phent);
997 AUXARGS_ENTRY(pos, AT_PHNUM, args->phnum);
998 AUXARGS_ENTRY(pos, AT_PAGESZ, args->pagesz);
999 AUXARGS_ENTRY(pos, AT_FLAGS, args->flags);
1000 AUXARGS_ENTRY(pos, AT_ENTRY, args->entry);
1001 AUXARGS_ENTRY(pos, AT_BASE, args->base);
1002 if (imgp->execpathp != 0)
1003 AUXARGS_ENTRY(pos, AT_EXECPATH, imgp->execpathp);
1004 AUXARGS_ENTRY(pos, AT_OSRELDATE, osreldate);
1005 if (imgp->canary != 0) {
1006 AUXARGS_ENTRY(pos, AT_CANARY, imgp->canary);
1007 AUXARGS_ENTRY(pos, AT_CANARYLEN, imgp->canarylen);
1008 }
1009 AUXARGS_ENTRY(pos, AT_NCPUS, mp_ncpus);
1010 if (imgp->pagesizes != 0) {
1011 AUXARGS_ENTRY(pos, AT_PAGESIZES, imgp->pagesizes);
1012 AUXARGS_ENTRY(pos, AT_PAGESIZESLEN, imgp->pagesizeslen);
1013 }
1014 AUXARGS_ENTRY(pos, AT_STACKPROT, imgp->sysent->sv_shared_page_obj
1015 != NULL && imgp->stack_prot != 0 ? imgp->stack_prot :
1016 imgp->sysent->sv_stackprot);
1017 AUXARGS_ENTRY(pos, AT_NULL, 0);
1018
1019 free(imgp->auxargs, M_TEMP);
1020 imgp->auxargs = NULL;
1021
1022 base--;
1023 suword(base, (long)imgp->args->argc);
1024 *stack_base = (register_t *)base;
1025 return (0);
1026 }
1027
1028 /*
1029 * Code for generating ELF core dumps.
1030 */
1031
1032 typedef void (*segment_callback)(vm_map_entry_t, void *);
1033
1034 /* Closure for cb_put_phdr(). */
1035 struct phdr_closure {
1036 Elf_Phdr *phdr; /* Program header to fill in */
1037 Elf_Off offset; /* Offset of segment in core file */
1038 };
1039
1040 /* Closure for cb_size_segment(). */
1041 struct sseg_closure {
1042 int count; /* Count of writable segments. */
1043 size_t size; /* Total size of all writable segments. */
1044 };
1045
1046 static void cb_put_phdr(vm_map_entry_t, void *);
1047 static void cb_size_segment(vm_map_entry_t, void *);
1048 static void each_writable_segment(struct thread *, segment_callback, void *);
1049 static int __elfN(corehdr)(struct thread *, struct vnode *, struct ucred *,
1050 int, void *, size_t, gzFile);
1051 static void __elfN(puthdr)(struct thread *, void *, size_t *, int);
1052 static void __elfN(putnote)(void *, size_t *, const char *, int,
1053 const void *, size_t);
1054
1055 #ifdef COMPRESS_USER_CORES
1056 extern int compress_user_cores;
1057 extern int compress_user_cores_gzlevel;
1058 #endif
1059
1060 static int
1061 core_output(struct vnode *vp, void *base, size_t len, off_t offset,
1062 struct ucred *active_cred, struct ucred *file_cred,
1063 struct thread *td, char *core_buf, gzFile gzfile) {
1064
1065 int error;
1066 if (gzfile) {
1067 #ifdef COMPRESS_USER_CORES
1068 error = compress_core(gzfile, base, core_buf, len, td);
1069 #else
1070 panic("shouldn't be here");
1071 #endif
1072 } else {
1073 error = vn_rdwr_inchunks(UIO_WRITE, vp, base, len, offset,
1074 UIO_USERSPACE, IO_UNIT | IO_DIRECT, active_cred, file_cred,
1075 NULL, td);
1076 }
1077 return (error);
1078 }
1079
1080 int
1081 __elfN(coredump)(struct thread *td, struct vnode *vp, off_t limit, int flags)
1082 {
1083 struct ucred *cred = td->td_ucred;
1084 int error = 0;
1085 struct sseg_closure seginfo;
1086 void *hdr;
1087 size_t hdrsize;
1088
1089 gzFile gzfile = Z_NULL;
1090 char *core_buf = NULL;
1091 #ifdef COMPRESS_USER_CORES
1092 char gzopen_flags[8];
1093 char *p;
1094 int doing_compress = flags & IMGACT_CORE_COMPRESS;
1095 #endif
1096
1097 hdr = NULL;
1098
1099 #ifdef COMPRESS_USER_CORES
1100 if (doing_compress) {
1101 p = gzopen_flags;
1102 *p++ = 'w';
1103 if (compress_user_cores_gzlevel >= 0 &&
1104 compress_user_cores_gzlevel <= 9)
1105 *p++ = '' + compress_user_cores_gzlevel;
1106 *p = 0;
1107 gzfile = gz_open("", gzopen_flags, vp);
1108 if (gzfile == Z_NULL) {
1109 error = EFAULT;
1110 goto done;
1111 }
1112 core_buf = malloc(CORE_BUF_SIZE, M_TEMP, M_WAITOK | M_ZERO);
1113 if (!core_buf) {
1114 error = ENOMEM;
1115 goto done;
1116 }
1117 }
1118 #endif
1119
1120 /* Size the program segments. */
1121 seginfo.count = 0;
1122 seginfo.size = 0;
1123 each_writable_segment(td, cb_size_segment, &seginfo);
1124
1125 /*
1126 * Calculate the size of the core file header area by making
1127 * a dry run of generating it. Nothing is written, but the
1128 * size is calculated.
1129 */
1130 hdrsize = 0;
1131 __elfN(puthdr)(td, (void *)NULL, &hdrsize, seginfo.count);
1132
1133 #ifdef RACCT
1134 PROC_LOCK(td->td_proc);
1135 error = racct_add(td->td_proc, RACCT_CORE, hdrsize + seginfo.size);
1136 PROC_UNLOCK(td->td_proc);
1137 if (error != 0) {
1138 error = EFAULT;
1139 goto done;
1140 }
1141 #endif
1142 if (hdrsize + seginfo.size >= limit) {
1143 error = EFAULT;
1144 goto done;
1145 }
1146
1147 /*
1148 * Allocate memory for building the header, fill it up,
1149 * and write it out.
1150 */
1151 hdr = malloc(hdrsize, M_TEMP, M_WAITOK);
1152 if (hdr == NULL) {
1153 error = EINVAL;
1154 goto done;
1155 }
1156 error = __elfN(corehdr)(td, vp, cred, seginfo.count, hdr, hdrsize,
1157 gzfile);
1158
1159 /* Write the contents of all of the writable segments. */
1160 if (error == 0) {
1161 Elf_Phdr *php;
1162 off_t offset;
1163 int i;
1164
1165 php = (Elf_Phdr *)((char *)hdr + sizeof(Elf_Ehdr)) + 1;
1166 offset = hdrsize;
1167 for (i = 0; i < seginfo.count; i++) {
1168 error = core_output(vp, (caddr_t)(uintptr_t)php->p_vaddr,
1169 php->p_filesz, offset, cred, NOCRED, curthread, core_buf, gzfile);
1170 if (error != 0)
1171 break;
1172 offset += php->p_filesz;
1173 php++;
1174 }
1175 }
1176 if (error) {
1177 log(LOG_WARNING,
1178 "Failed to write core file for process %s (error %d)\n",
1179 curproc->p_comm, error);
1180 }
1181
1182 done:
1183 #ifdef COMPRESS_USER_CORES
1184 if (core_buf)
1185 free(core_buf, M_TEMP);
1186 if (gzfile)
1187 gzclose(gzfile);
1188 #endif
1189
1190 free(hdr, M_TEMP);
1191
1192 return (error);
1193 }
1194
1195 /*
1196 * A callback for each_writable_segment() to write out the segment's
1197 * program header entry.
1198 */
1199 static void
1200 cb_put_phdr(entry, closure)
1201 vm_map_entry_t entry;
1202 void *closure;
1203 {
1204 struct phdr_closure *phc = (struct phdr_closure *)closure;
1205 Elf_Phdr *phdr = phc->phdr;
1206
1207 phc->offset = round_page(phc->offset);
1208
1209 phdr->p_type = PT_LOAD;
1210 phdr->p_offset = phc->offset;
1211 phdr->p_vaddr = entry->start;
1212 phdr->p_paddr = 0;
1213 phdr->p_filesz = phdr->p_memsz = entry->end - entry->start;
1214 phdr->p_align = PAGE_SIZE;
1215 phdr->p_flags = __elfN(untrans_prot)(entry->protection);
1216
1217 phc->offset += phdr->p_filesz;
1218 phc->phdr++;
1219 }
1220
1221 /*
1222 * A callback for each_writable_segment() to gather information about
1223 * the number of segments and their total size.
1224 */
1225 static void
1226 cb_size_segment(entry, closure)
1227 vm_map_entry_t entry;
1228 void *closure;
1229 {
1230 struct sseg_closure *ssc = (struct sseg_closure *)closure;
1231
1232 ssc->count++;
1233 ssc->size += entry->end - entry->start;
1234 }
1235
1236 /*
1237 * For each writable segment in the process's memory map, call the given
1238 * function with a pointer to the map entry and some arbitrary
1239 * caller-supplied data.
1240 */
1241 static void
1242 each_writable_segment(td, func, closure)
1243 struct thread *td;
1244 segment_callback func;
1245 void *closure;
1246 {
1247 struct proc *p = td->td_proc;
1248 vm_map_t map = &p->p_vmspace->vm_map;
1249 vm_map_entry_t entry;
1250 vm_object_t backing_object, object;
1251 boolean_t ignore_entry;
1252
1253 vm_map_lock_read(map);
1254 for (entry = map->header.next; entry != &map->header;
1255 entry = entry->next) {
1256 /*
1257 * Don't dump inaccessible mappings, deal with legacy
1258 * coredump mode.
1259 *
1260 * Note that read-only segments related to the elf binary
1261 * are marked MAP_ENTRY_NOCOREDUMP now so we no longer
1262 * need to arbitrarily ignore such segments.
1263 */
1264 if (elf_legacy_coredump) {
1265 if ((entry->protection & VM_PROT_RW) != VM_PROT_RW)
1266 continue;
1267 } else {
1268 if ((entry->protection & VM_PROT_ALL) == 0)
1269 continue;
1270 }
1271
1272 /*
1273 * Dont include memory segment in the coredump if
1274 * MAP_NOCORE is set in mmap(2) or MADV_NOCORE in
1275 * madvise(2). Do not dump submaps (i.e. parts of the
1276 * kernel map).
1277 */
1278 if (entry->eflags & (MAP_ENTRY_NOCOREDUMP|MAP_ENTRY_IS_SUB_MAP))
1279 continue;
1280
1281 if ((object = entry->object.vm_object) == NULL)
1282 continue;
1283
1284 /* Ignore memory-mapped devices and such things. */
1285 VM_OBJECT_LOCK(object);
1286 while ((backing_object = object->backing_object) != NULL) {
1287 VM_OBJECT_LOCK(backing_object);
1288 VM_OBJECT_UNLOCK(object);
1289 object = backing_object;
1290 }
1291 ignore_entry = object->type != OBJT_DEFAULT &&
1292 object->type != OBJT_SWAP && object->type != OBJT_VNODE;
1293 VM_OBJECT_UNLOCK(object);
1294 if (ignore_entry)
1295 continue;
1296
1297 (*func)(entry, closure);
1298 }
1299 vm_map_unlock_read(map);
1300 }
1301
1302 /*
1303 * Write the core file header to the file, including padding up to
1304 * the page boundary.
1305 */
1306 static int
1307 __elfN(corehdr)(td, vp, cred, numsegs, hdr, hdrsize, gzfile)
1308 struct thread *td;
1309 struct vnode *vp;
1310 struct ucred *cred;
1311 int numsegs;
1312 size_t hdrsize;
1313 void *hdr;
1314 gzFile gzfile;
1315 {
1316 size_t off;
1317
1318 /* Fill in the header. */
1319 bzero(hdr, hdrsize);
1320 off = 0;
1321 __elfN(puthdr)(td, hdr, &off, numsegs);
1322
1323 if (!gzfile) {
1324 /* Write it to the core file. */
1325 return (vn_rdwr_inchunks(UIO_WRITE, vp, hdr, hdrsize, (off_t)0,
1326 UIO_SYSSPACE, IO_UNIT | IO_DIRECT, cred, NOCRED, NULL,
1327 td));
1328 } else {
1329 #ifdef COMPRESS_USER_CORES
1330 if (gzwrite(gzfile, hdr, hdrsize) != hdrsize) {
1331 log(LOG_WARNING,
1332 "Failed to compress core file header for process"
1333 " %s.\n", curproc->p_comm);
1334 return (EFAULT);
1335 }
1336 else {
1337 return (0);
1338 }
1339 #else
1340 panic("shouldn't be here");
1341 #endif
1342 }
1343 }
1344
1345 #if defined(COMPAT_FREEBSD32) && __ELF_WORD_SIZE == 32
1346 #include <compat/freebsd32/freebsd32.h>
1347
1348 typedef struct prstatus32 elf_prstatus_t;
1349 typedef struct prpsinfo32 elf_prpsinfo_t;
1350 typedef struct fpreg32 elf_prfpregset_t;
1351 typedef struct fpreg32 elf_fpregset_t;
1352 typedef struct reg32 elf_gregset_t;
1353 typedef struct thrmisc32 elf_thrmisc_t;
1354 #else
1355 typedef prstatus_t elf_prstatus_t;
1356 typedef prpsinfo_t elf_prpsinfo_t;
1357 typedef prfpregset_t elf_prfpregset_t;
1358 typedef prfpregset_t elf_fpregset_t;
1359 typedef gregset_t elf_gregset_t;
1360 typedef thrmisc_t elf_thrmisc_t;
1361 #endif
1362
1363 static void
1364 __elfN(puthdr)(struct thread *td, void *dst, size_t *off, int numsegs)
1365 {
1366 struct {
1367 elf_prstatus_t status;
1368 elf_prfpregset_t fpregset;
1369 elf_prpsinfo_t psinfo;
1370 elf_thrmisc_t thrmisc;
1371 } *tempdata;
1372 elf_prstatus_t *status;
1373 elf_prfpregset_t *fpregset;
1374 elf_prpsinfo_t *psinfo;
1375 elf_thrmisc_t *thrmisc;
1376 struct proc *p;
1377 struct thread *thr;
1378 size_t ehoff, noteoff, notesz, phoff;
1379
1380 p = td->td_proc;
1381
1382 ehoff = *off;
1383 *off += sizeof(Elf_Ehdr);
1384
1385 phoff = *off;
1386 *off += (numsegs + 1) * sizeof(Elf_Phdr);
1387
1388 noteoff = *off;
1389 /*
1390 * Don't allocate space for the notes if we're just calculating
1391 * the size of the header. We also don't collect the data.
1392 */
1393 if (dst != NULL) {
1394 tempdata = malloc(sizeof(*tempdata), M_TEMP, M_ZERO|M_WAITOK);
1395 status = &tempdata->status;
1396 fpregset = &tempdata->fpregset;
1397 psinfo = &tempdata->psinfo;
1398 thrmisc = &tempdata->thrmisc;
1399 } else {
1400 tempdata = NULL;
1401 status = NULL;
1402 fpregset = NULL;
1403 psinfo = NULL;
1404 thrmisc = NULL;
1405 }
1406
1407 if (dst != NULL) {
1408 psinfo->pr_version = PRPSINFO_VERSION;
1409 psinfo->pr_psinfosz = sizeof(elf_prpsinfo_t);
1410 strlcpy(psinfo->pr_fname, p->p_comm, sizeof(psinfo->pr_fname));
1411 /*
1412 * XXX - We don't fill in the command line arguments properly
1413 * yet.
1414 */
1415 strlcpy(psinfo->pr_psargs, p->p_comm,
1416 sizeof(psinfo->pr_psargs));
1417 }
1418 __elfN(putnote)(dst, off, "FreeBSD", NT_PRPSINFO, psinfo,
1419 sizeof *psinfo);
1420
1421 /*
1422 * To have the debugger select the right thread (LWP) as the initial
1423 * thread, we dump the state of the thread passed to us in td first.
1424 * This is the thread that causes the core dump and thus likely to
1425 * be the right thread one wants to have selected in the debugger.
1426 */
1427 thr = td;
1428 while (thr != NULL) {
1429 if (dst != NULL) {
1430 status->pr_version = PRSTATUS_VERSION;
1431 status->pr_statussz = sizeof(elf_prstatus_t);
1432 status->pr_gregsetsz = sizeof(elf_gregset_t);
1433 status->pr_fpregsetsz = sizeof(elf_fpregset_t);
1434 status->pr_osreldate = osreldate;
1435 status->pr_cursig = p->p_sig;
1436 status->pr_pid = thr->td_tid;
1437 #if defined(COMPAT_FREEBSD32) && __ELF_WORD_SIZE == 32
1438 fill_regs32(thr, &status->pr_reg);
1439 fill_fpregs32(thr, fpregset);
1440 #else
1441 fill_regs(thr, &status->pr_reg);
1442 fill_fpregs(thr, fpregset);
1443 #endif
1444 memset(&thrmisc->_pad, 0, sizeof (thrmisc->_pad));
1445 strcpy(thrmisc->pr_tname, thr->td_name);
1446 }
1447 __elfN(putnote)(dst, off, "FreeBSD", NT_PRSTATUS, status,
1448 sizeof *status);
1449 __elfN(putnote)(dst, off, "FreeBSD", NT_FPREGSET, fpregset,
1450 sizeof *fpregset);
1451 __elfN(putnote)(dst, off, "FreeBSD", NT_THRMISC, thrmisc,
1452 sizeof *thrmisc);
1453 /*
1454 * Allow for MD specific notes, as well as any MD
1455 * specific preparations for writing MI notes.
1456 */
1457 __elfN(dump_thread)(thr, dst, off);
1458
1459 thr = (thr == td) ? TAILQ_FIRST(&p->p_threads) :
1460 TAILQ_NEXT(thr, td_plist);
1461 if (thr == td)
1462 thr = TAILQ_NEXT(thr, td_plist);
1463 }
1464
1465 notesz = *off - noteoff;
1466
1467 if (dst != NULL)
1468 free(tempdata, M_TEMP);
1469
1470 /* Align up to a page boundary for the program segments. */
1471 *off = round_page(*off);
1472
1473 if (dst != NULL) {
1474 Elf_Ehdr *ehdr;
1475 Elf_Phdr *phdr;
1476 struct phdr_closure phc;
1477
1478 /*
1479 * Fill in the ELF header.
1480 */
1481 ehdr = (Elf_Ehdr *)((char *)dst + ehoff);
1482 ehdr->e_ident[EI_MAG0] = ELFMAG0;
1483 ehdr->e_ident[EI_MAG1] = ELFMAG1;
1484 ehdr->e_ident[EI_MAG2] = ELFMAG2;
1485 ehdr->e_ident[EI_MAG3] = ELFMAG3;
1486 ehdr->e_ident[EI_CLASS] = ELF_CLASS;
1487 ehdr->e_ident[EI_DATA] = ELF_DATA;
1488 ehdr->e_ident[EI_VERSION] = EV_CURRENT;
1489 ehdr->e_ident[EI_OSABI] = ELFOSABI_FREEBSD;
1490 ehdr->e_ident[EI_ABIVERSION] = 0;
1491 ehdr->e_ident[EI_PAD] = 0;
1492 ehdr->e_type = ET_CORE;
1493 #if defined(COMPAT_FREEBSD32) && __ELF_WORD_SIZE == 32
1494 ehdr->e_machine = ELF_ARCH32;
1495 #else
1496 ehdr->e_machine = ELF_ARCH;
1497 #endif
1498 ehdr->e_version = EV_CURRENT;
1499 ehdr->e_entry = 0;
1500 ehdr->e_phoff = phoff;
1501 ehdr->e_flags = 0;
1502 ehdr->e_ehsize = sizeof(Elf_Ehdr);
1503 ehdr->e_phentsize = sizeof(Elf_Phdr);
1504 ehdr->e_phnum = numsegs + 1;
1505 ehdr->e_shentsize = sizeof(Elf_Shdr);
1506 ehdr->e_shnum = 0;
1507 ehdr->e_shstrndx = SHN_UNDEF;
1508
1509 /*
1510 * Fill in the program header entries.
1511 */
1512 phdr = (Elf_Phdr *)((char *)dst + phoff);
1513
1514 /* The note segement. */
1515 phdr->p_type = PT_NOTE;
1516 phdr->p_offset = noteoff;
1517 phdr->p_vaddr = 0;
1518 phdr->p_paddr = 0;
1519 phdr->p_filesz = notesz;
1520 phdr->p_memsz = 0;
1521 phdr->p_flags = 0;
1522 phdr->p_align = 0;
1523 phdr++;
1524
1525 /* All the writable segments from the program. */
1526 phc.phdr = phdr;
1527 phc.offset = *off;
1528 each_writable_segment(td, cb_put_phdr, &phc);
1529 }
1530 }
1531
1532 static void
1533 __elfN(putnote)(void *dst, size_t *off, const char *name, int type,
1534 const void *desc, size_t descsz)
1535 {
1536 Elf_Note note;
1537
1538 note.n_namesz = strlen(name) + 1;
1539 note.n_descsz = descsz;
1540 note.n_type = type;
1541 if (dst != NULL)
1542 bcopy(¬e, (char *)dst + *off, sizeof note);
1543 *off += sizeof note;
1544 if (dst != NULL)
1545 bcopy(name, (char *)dst + *off, note.n_namesz);
1546 *off += roundup2(note.n_namesz, sizeof(Elf_Size));
1547 if (dst != NULL)
1548 bcopy(desc, (char *)dst + *off, note.n_descsz);
1549 *off += roundup2(note.n_descsz, sizeof(Elf_Size));
1550 }
1551
1552 static boolean_t
1553 __elfN(parse_notes)(struct image_params *imgp, Elf_Brandnote *checknote,
1554 int32_t *osrel, const Elf_Phdr *pnote)
1555 {
1556 const Elf_Note *note, *note0, *note_end;
1557 const char *note_name;
1558 int i;
1559
1560 if (pnote == NULL || pnote->p_offset >= PAGE_SIZE ||
1561 pnote->p_offset + pnote->p_filesz >= PAGE_SIZE)
1562 return (FALSE);
1563
1564 note = note0 = (const Elf_Note *)(imgp->image_header + pnote->p_offset);
1565 note_end = (const Elf_Note *)(imgp->image_header +
1566 pnote->p_offset + pnote->p_filesz);
1567 for (i = 0; i < 100 && note >= note0 && note < note_end; i++) {
1568 if (!aligned(note, Elf32_Addr))
1569 return (FALSE);
1570 if (note->n_namesz != checknote->hdr.n_namesz ||
1571 note->n_descsz != checknote->hdr.n_descsz ||
1572 note->n_type != checknote->hdr.n_type)
1573 goto nextnote;
1574 note_name = (const char *)(note + 1);
1575 if (strncmp(checknote->vendor, note_name,
1576 checknote->hdr.n_namesz) != 0)
1577 goto nextnote;
1578
1579 /*
1580 * Fetch the osreldate for binary
1581 * from the ELF OSABI-note if necessary.
1582 */
1583 if ((checknote->flags & BN_TRANSLATE_OSREL) != 0 &&
1584 checknote->trans_osrel != NULL)
1585 return (checknote->trans_osrel(note, osrel));
1586 return (TRUE);
1587
1588 nextnote:
1589 note = (const Elf_Note *)((const char *)(note + 1) +
1590 roundup2(note->n_namesz, sizeof(Elf32_Addr)) +
1591 roundup2(note->n_descsz, sizeof(Elf32_Addr)));
1592 }
1593
1594 return (FALSE);
1595 }
1596
1597 /*
1598 * Try to find the appropriate ABI-note section for checknote,
1599 * fetch the osreldate for binary from the ELF OSABI-note. Only the
1600 * first page of the image is searched, the same as for headers.
1601 */
1602 static boolean_t
1603 __elfN(check_note)(struct image_params *imgp, Elf_Brandnote *checknote,
1604 int32_t *osrel)
1605 {
1606 const Elf_Phdr *phdr;
1607 const Elf_Ehdr *hdr;
1608 int i;
1609
1610 hdr = (const Elf_Ehdr *)imgp->image_header;
1611 phdr = (const Elf_Phdr *)(imgp->image_header + hdr->e_phoff);
1612
1613 for (i = 0; i < hdr->e_phnum; i++) {
1614 if (phdr[i].p_type == PT_NOTE &&
1615 __elfN(parse_notes)(imgp, checknote, osrel, &phdr[i]))
1616 return (TRUE);
1617 }
1618 return (FALSE);
1619
1620 }
1621
1622 /*
1623 * Tell kern_execve.c about it, with a little help from the linker.
1624 */
1625 static struct execsw __elfN(execsw) = {
1626 __CONCAT(exec_, __elfN(imgact)),
1627 __XSTRING(__CONCAT(ELF, __ELF_WORD_SIZE))
1628 };
1629 EXEC_SET(__CONCAT(elf, __ELF_WORD_SIZE), __elfN(execsw));
1630
1631 #ifdef COMPRESS_USER_CORES
1632 /*
1633 * Compress and write out a core segment for a user process.
1634 *
1635 * 'inbuf' is the starting address of a VM segment in the process' address
1636 * space that is to be compressed and written out to the core file. 'dest_buf'
1637 * is a buffer in the kernel's address space. The segment is copied from
1638 * 'inbuf' to 'dest_buf' first before being processed by the compression
1639 * routine gzwrite(). This copying is necessary because the content of the VM
1640 * segment may change between the compression pass and the crc-computation pass
1641 * in gzwrite(). This is because realtime threads may preempt the UNIX kernel.
1642 */
1643 static int
1644 compress_core (gzFile file, char *inbuf, char *dest_buf, unsigned int len,
1645 struct thread *td)
1646 {
1647 int len_compressed;
1648 int error = 0;
1649 unsigned int chunk_len;
1650
1651 while (len) {
1652 chunk_len = (len > CORE_BUF_SIZE) ? CORE_BUF_SIZE : len;
1653 copyin(inbuf, dest_buf, chunk_len);
1654 len_compressed = gzwrite(file, dest_buf, chunk_len);
1655
1656 EVENTHANDLER_INVOKE(app_coredump_progress, td, len_compressed);
1657
1658 if ((unsigned int)len_compressed != chunk_len) {
1659 log(LOG_WARNING,
1660 "compress_core: length mismatch (0x%x returned, "
1661 "0x%x expected)\n", len_compressed, chunk_len);
1662 EVENTHANDLER_INVOKE(app_coredump_error, td,
1663 "compress_core: length mismatch %x -> %x",
1664 chunk_len, len_compressed);
1665 error = EFAULT;
1666 break;
1667 }
1668 inbuf += chunk_len;
1669 len -= chunk_len;
1670 maybe_yield();
1671 }
1672
1673 return (error);
1674 }
1675 #endif /* COMPRESS_USER_CORES */
1676
1677 static vm_prot_t
1678 __elfN(trans_prot)(Elf_Word flags)
1679 {
1680 vm_prot_t prot;
1681
1682 prot = 0;
1683 if (flags & PF_X)
1684 prot |= VM_PROT_EXECUTE;
1685 if (flags & PF_W)
1686 prot |= VM_PROT_WRITE;
1687 if (flags & PF_R)
1688 prot |= VM_PROT_READ;
1689 #if __ELF_WORD_SIZE == 32
1690 #if defined(__amd64__) || defined(__ia64__)
1691 if (i386_read_exec && (flags & PF_R))
1692 prot |= VM_PROT_EXECUTE;
1693 #endif
1694 #endif
1695 return (prot);
1696 }
1697
1698 static Elf_Word
1699 __elfN(untrans_prot)(vm_prot_t prot)
1700 {
1701 Elf_Word flags;
1702
1703 flags = 0;
1704 if (prot & VM_PROT_EXECUTE)
1705 flags |= PF_X;
1706 if (prot & VM_PROT_READ)
1707 flags |= PF_R;
1708 if (prot & VM_PROT_WRITE)
1709 flags |= PF_W;
1710 return (flags);
1711 }
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