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 * $FreeBSD: src/sys/kern/imgact_elf.c,v 1.73.2.13 2002/12/28 19:49:41 dillon Exp $
31 */
32
33 #include <sys/param.h>
34 #include <sys/exec.h>
35 #include <sys/fcntl.h>
36 #include <sys/file.h>
37 #include <sys/imgact.h>
38 #include <sys/imgact_elf.h>
39 #include <sys/kernel.h>
40 #include <sys/malloc.h>
41 #include <sys/mman.h>
42 #include <sys/systm.h>
43 #include <sys/proc.h>
44 #include <sys/nlookup.h>
45 #include <sys/pioctl.h>
46 #include <sys/procfs.h>
47 #include <sys/resourcevar.h>
48 #include <sys/signalvar.h>
49 #include <sys/stat.h>
50 #include <sys/syscall.h>
51 #include <sys/sysctl.h>
52 #include <sys/sysent.h>
53 #include <sys/vnode.h>
54 #include <sys/eventhandler.h>
55
56 #include <cpu/lwbuf.h>
57
58 #include <vm/vm.h>
59 #include <vm/vm_kern.h>
60 #include <vm/vm_param.h>
61 #include <vm/pmap.h>
62 #include <sys/lock.h>
63 #include <vm/vm_map.h>
64 #include <vm/vm_object.h>
65 #include <vm/vm_extern.h>
66
67 #include <machine/elf.h>
68 #include <machine/md_var.h>
69 #include <sys/mount.h>
70 #include <sys/ckpt.h>
71
72 #define OLD_EI_BRAND 8
73 #define truncps(va,ps) rounddown2(va, ps)
74 #define aligned(a,t) (truncps((u_long)(a), sizeof(t)) == (u_long)(a))
75
76 static int __elfN(check_header)(const Elf_Ehdr *hdr);
77 static Elf_Brandinfo *__elfN(get_brandinfo)(struct image_params *imgp,
78 const char *interp, int32_t *osrel);
79 static int __elfN(load_file)(struct proc *p, const char *file, u_long *addr,
80 u_long *entry);
81 static int __elfN(load_section)(struct proc *p,
82 struct vmspace *vmspace, struct vnode *vp,
83 vm_offset_t offset, caddr_t vmaddr, size_t memsz, size_t filsz,
84 vm_prot_t prot);
85 static int __CONCAT(exec_, __elfN(imgact))(struct image_params *imgp);
86 static boolean_t __elfN(bsd_trans_osrel)(const Elf_Note *note,
87 int32_t *osrel);
88 static boolean_t __elfN(check_note)(struct image_params *imgp,
89 Elf_Brandnote *checknote, int32_t *osrel);
90 static vm_prot_t __elfN(trans_prot)(Elf_Word);
91 static Elf_Word __elfN(untrans_prot)(vm_prot_t);
92 static boolean_t check_PT_NOTE(struct image_params *imgp,
93 Elf_Brandnote *checknote, int32_t *osrel, const Elf_Phdr * pnote);
94 static boolean_t extract_interpreter(struct image_params *imgp,
95 const Elf_Phdr *pinterpreter, char *data);
96 static u_long pie_base_hint(struct proc *p);
97
98 static int elf_legacy_coredump = 0;
99 static int __elfN(fallback_brand) = -1;
100 static int elf_pie_base_mmap = 0;
101 #if defined(__x86_64__)
102 SYSCTL_NODE(_kern, OID_AUTO, elf64, CTLFLAG_RW, 0, "");
103 SYSCTL_INT(_debug, OID_AUTO, elf64_legacy_coredump, CTLFLAG_RW,
104 &elf_legacy_coredump, 0, "legacy coredump mode");
105 SYSCTL_INT(_kern_elf64, OID_AUTO, fallback_brand, CTLFLAG_RW,
106 &elf64_fallback_brand, 0, "ELF64 brand of last resort");
107 TUNABLE_INT("kern.elf64.fallback_brand", &elf64_fallback_brand);
108 SYSCTL_INT(_kern_elf64, OID_AUTO, pie_base_mmap, CTLFLAG_RW,
109 &elf_pie_base_mmap, 0,
110 "choose a base address for PIE as if it is mapped with mmap()");
111 TUNABLE_INT("kern.elf64.pie_base_mmap", &elf_pie_base_mmap);
112 #else /* i386 assumed */
113 SYSCTL_NODE(_kern, OID_AUTO, elf32, CTLFLAG_RW, 0, "");
114 SYSCTL_INT(_debug, OID_AUTO, elf32_legacy_coredump, CTLFLAG_RW,
115 &elf_legacy_coredump, 0, "legacy coredump mode");
116 SYSCTL_INT(_kern_elf32, OID_AUTO, fallback_brand, CTLFLAG_RW,
117 &elf32_fallback_brand, 0, "ELF32 brand of last resort");
118 TUNABLE_INT("kern.elf32.fallback_brand", &elf32_fallback_brand);
119 SYSCTL_INT(_kern_elf32, OID_AUTO, pie_base_mmap, CTLFLAG_RW,
120 &elf_pie_base_mmap, 0,
121 "choose a base address for PIE as if it is mapped with mmap()");
122 TUNABLE_INT("kern.elf32.pie_base_mmap", &elf_pie_base_mmap);
123 #endif
124
125 static Elf_Brandinfo *elf_brand_list[MAX_BRANDS];
126
127 static const char DRAGONFLY_ABI_VENDOR[] = "DragonFly";
128
129 Elf_Brandnote __elfN(dragonfly_brandnote) = {
130 .hdr.n_namesz = sizeof(DRAGONFLY_ABI_VENDOR),
131 .hdr.n_descsz = sizeof(int32_t),
132 .hdr.n_type = 1,
133 .vendor = DRAGONFLY_ABI_VENDOR,
134 .flags = BN_TRANSLATE_OSREL,
135 .trans_osrel = __elfN(bsd_trans_osrel),
136 };
137
138 int
__elfN(insert_brand_entry)139 __elfN(insert_brand_entry)(Elf_Brandinfo *entry)
140 {
141 int i;
142
143 for (i = 0; i < MAX_BRANDS; i++) {
144 if (elf_brand_list[i] == NULL) {
145 elf_brand_list[i] = entry;
146 break;
147 }
148 }
149 if (i == MAX_BRANDS) {
150 uprintf("WARNING: %s: could not insert brandinfo entry: %p\n",
151 __func__, entry);
152 return (-1);
153 }
154 return (0);
155 }
156
157 int
__elfN(remove_brand_entry)158 __elfN(remove_brand_entry)(Elf_Brandinfo *entry)
159 {
160 int i;
161
162 for (i = 0; i < MAX_BRANDS; i++) {
163 if (elf_brand_list[i] == entry) {
164 elf_brand_list[i] = NULL;
165 break;
166 }
167 }
168 if (i == MAX_BRANDS)
169 return (-1);
170 return (0);
171 }
172
173 /*
174 * Check if an elf brand is being used anywhere in the system.
175 *
176 * Used by the linux emulation module unloader. This isn't safe from
177 * races.
178 */
179 struct elf_brand_inuse_info {
180 int rval;
181 Elf_Brandinfo *entry;
182 };
183
184 static int elf_brand_inuse_callback(struct proc *p, void *data);
185
186 int
__elfN(brand_inuse)187 __elfN(brand_inuse)(Elf_Brandinfo *entry)
188 {
189 struct elf_brand_inuse_info info;
190
191 info.rval = FALSE;
192 info.entry = entry;
193 allproc_scan(elf_brand_inuse_callback, &info, 0);
194 return (info.rval);
195 }
196
197 static
198 int
elf_brand_inuse_callback(struct proc * p,void * data)199 elf_brand_inuse_callback(struct proc *p, void *data)
200 {
201 struct elf_brand_inuse_info *info = data;
202
203 if (p->p_sysent == info->entry->sysvec) {
204 info->rval = TRUE;
205 return (-1);
206 }
207 return (0);
208 }
209
210 static int
__elfN(check_header)211 __elfN(check_header)(const Elf_Ehdr *hdr)
212 {
213 Elf_Brandinfo *bi;
214 int i;
215
216 if (!IS_ELF(*hdr) ||
217 hdr->e_ident[EI_CLASS] != ELF_TARG_CLASS ||
218 hdr->e_ident[EI_DATA] != ELF_TARG_DATA ||
219 hdr->e_ident[EI_VERSION] != EV_CURRENT ||
220 hdr->e_phentsize != sizeof(Elf_Phdr) ||
221 hdr->e_ehsize != sizeof(Elf_Ehdr) ||
222 hdr->e_version != ELF_TARG_VER)
223 return (ENOEXEC);
224
225 /*
226 * Make sure we have at least one brand for this machine.
227 */
228
229 for (i = 0; i < MAX_BRANDS; i++) {
230 bi = elf_brand_list[i];
231 if (bi != NULL && bi->machine == hdr->e_machine)
232 break;
233 }
234 if (i == MAX_BRANDS)
235 return (ENOEXEC);
236
237 return (0);
238 }
239
240 static int
__elfN(load_section)241 __elfN(load_section)(struct proc *p, struct vmspace *vmspace, struct vnode *vp,
242 vm_offset_t offset, caddr_t vmaddr, size_t memsz,
243 size_t filsz, vm_prot_t prot)
244 {
245 size_t map_len;
246 vm_offset_t map_addr;
247 int error, rv, cow;
248 int count;
249 int shared;
250 size_t copy_len;
251 vm_object_t object;
252 vm_offset_t file_addr;
253
254 object = vp->v_object;
255 error = 0;
256
257 /*
258 * In most cases we will be able to use a shared lock on the
259 * object we are inserting into the map. The lock will be
260 * upgraded in situations where new VM pages must be allocated.
261 */
262 vm_object_hold_shared(object);
263 shared = 1;
264
265 /*
266 * It's necessary to fail if the filsz + offset taken from the
267 * header is greater than the actual file pager object's size.
268 * If we were to allow this, then the vm_map_find() below would
269 * walk right off the end of the file object and into the ether.
270 *
271 * While I'm here, might as well check for something else that
272 * is invalid: filsz cannot be greater than memsz.
273 */
274 if ((off_t)filsz + offset > vp->v_filesize || filsz > memsz) {
275 uprintf("elf_load_section: truncated ELF file\n");
276 vm_object_drop(object);
277 return (ENOEXEC);
278 }
279
280 map_addr = trunc_page((vm_offset_t)vmaddr);
281 file_addr = trunc_page(offset);
282
283 /*
284 * We have two choices. We can either clear the data in the last page
285 * of an oversized mapping, or we can start the anon mapping a page
286 * early and copy the initialized data into that first page. We
287 * choose the second..
288 */
289 if (memsz > filsz)
290 map_len = trunc_page(offset+filsz) - file_addr;
291 else
292 map_len = round_page(offset+filsz) - file_addr;
293
294 if (map_len != 0) {
295 vm_object_reference_locked(object);
296
297 /* cow flags: don't dump readonly sections in core */
298 cow = MAP_COPY_ON_WRITE | MAP_PREFAULT;
299 if ((prot & VM_PROT_WRITE) == 0)
300 cow |= MAP_DISABLE_COREDUMP;
301 if (shared == 0)
302 cow |= MAP_PREFAULT_RELOCK;
303
304 count = vm_map_entry_reserve(MAP_RESERVE_COUNT);
305 vm_map_lock(&vmspace->vm_map);
306 rv = vm_map_insert(&vmspace->vm_map, &count,
307 object, NULL,
308 file_addr, NULL, /* file offset */
309 map_addr, /* virtual start */
310 map_addr + map_len,/* virtual end */
311 VM_MAPTYPE_NORMAL,
312 VM_SUBSYS_IMGACT,
313 prot, VM_PROT_ALL, cow);
314 vm_map_unlock(&vmspace->vm_map);
315 vm_map_entry_release(count);
316
317 /*
318 * NOTE: Object must have a hold ref when calling
319 * vm_object_deallocate().
320 */
321 if (rv != KERN_SUCCESS) {
322 vm_object_deallocate_locked(object);
323 vm_object_drop(object);
324 return (EINVAL);
325 }
326
327 /* we can stop now if we've covered it all */
328 if (memsz == filsz) {
329 vm_object_drop(object);
330 return (0);
331 }
332 }
333
334 /*
335 * We have to get the remaining bit of the file into the first part
336 * of the oversized map segment. This is normally because the .data
337 * segment in the file is extended to provide bss. It's a neat idea
338 * to try and save a page, but it's a pain in the behind to implement.
339 */
340 copy_len = (offset + filsz) - trunc_page(offset + filsz);
341 map_addr = trunc_page((vm_offset_t)vmaddr + filsz);
342 map_len = round_page((vm_offset_t)vmaddr + memsz) - map_addr;
343
344 /* This had damn well better be true! */
345 if (map_len != 0) {
346 count = vm_map_entry_reserve(MAP_RESERVE_COUNT);
347 vm_map_lock(&vmspace->vm_map);
348 rv = vm_map_insert(&vmspace->vm_map, &count,
349 NULL, NULL,
350 0, NULL,
351 map_addr,
352 map_addr + map_len,
353 VM_MAPTYPE_NORMAL,
354 VM_SUBSYS_IMGACT,
355 VM_PROT_ALL, VM_PROT_ALL, 0);
356 vm_map_unlock(&vmspace->vm_map);
357 vm_map_entry_release(count);
358 if (rv != KERN_SUCCESS) {
359 vm_object_drop(object);
360 return (EINVAL);
361 }
362 }
363
364 if (copy_len != 0) {
365 struct lwbuf *lwb;
366 struct lwbuf lwb_cache;
367 vm_page_t m;
368
369 m = vm_fault_object_page(object, trunc_page(offset + filsz),
370 VM_PROT_READ, 0, &shared, &error);
371 vm_object_drop(object);
372 if (m) {
373 lwb = lwbuf_alloc(m, &lwb_cache);
374 error = copyout((caddr_t)lwbuf_kva(lwb),
375 (caddr_t)map_addr, copy_len);
376 lwbuf_free(lwb);
377 vm_page_unhold(m);
378 }
379 } else {
380 vm_object_drop(object);
381 }
382
383 /*
384 * set it to the specified protection
385 */
386 if (error == 0) {
387 vm_map_protect(&vmspace->vm_map,
388 map_addr, map_addr + map_len,
389 prot, FALSE);
390 }
391 return (error);
392 }
393
394 /*
395 * Load the file "file" into memory. It may be either a shared object
396 * or an executable.
397 *
398 * The "addr" reference parameter is in/out. On entry, it specifies
399 * the address where a shared object should be loaded. If the file is
400 * an executable, this value is ignored. On exit, "addr" specifies
401 * where the file was actually loaded.
402 *
403 * The "entry" reference parameter is out only. On exit, it specifies
404 * the entry point for the loaded file.
405 */
406 static int
__elfN(load_file)407 __elfN(load_file)(struct proc *p, const char *file, u_long *addr, u_long *entry)
408 {
409 struct {
410 struct nlookupdata nd;
411 struct vattr_lite lva;
412 struct image_params image_params;
413 } *tempdata;
414 const Elf_Ehdr *hdr = NULL;
415 const Elf_Phdr *phdr = NULL;
416 struct nlookupdata *nd;
417 struct vmspace *vmspace = p->p_vmspace;
418 struct vattr_lite *lvap;
419 struct image_params *imgp;
420 struct mount *topmnt;
421 vm_prot_t prot;
422 u_long rbase;
423 u_long base_addr = 0;
424 int error, i, numsegs;
425
426 tempdata = kmalloc(sizeof(*tempdata), M_TEMP, M_WAITOK);
427 nd = &tempdata->nd;
428 lvap = &tempdata->lva;
429 imgp = &tempdata->image_params;
430
431 /*
432 * Initialize part of the common data
433 */
434 imgp->proc = p;
435 imgp->lvap = lvap;
436 imgp->firstpage = NULL;
437 imgp->image_header = NULL;
438 imgp->vp = NULL;
439
440 error = nlookup_init(nd, file, UIO_SYSSPACE, NLC_FOLLOW);
441 if (error == 0)
442 error = nlookup(nd);
443 if (error == 0)
444 error = cache_vget(&nd->nl_nch, nd->nl_cred,
445 LK_SHARED, &imgp->vp);
446 topmnt = nd->nl_nch.mount;
447 nlookup_done(nd);
448 if (error)
449 goto fail;
450
451 /*
452 * Check permissions, modes, uid, etc on the file, and "open" it.
453 */
454 error = exec_check_permissions(imgp, topmnt);
455 if (error) {
456 vn_unlock(imgp->vp);
457 goto fail;
458 }
459
460 error = exec_map_first_page(imgp);
461 /*
462 * Also make certain that the interpreter stays the same, so set
463 * its VTEXT flag, too.
464 */
465 if (error == 0)
466 vsetflags(imgp->vp, VTEXT);
467 vn_unlock(imgp->vp);
468 if (error)
469 goto fail;
470
471 hdr = (const Elf_Ehdr *)imgp->image_header;
472 if ((error = __elfN(check_header)(hdr)) != 0)
473 goto fail;
474 if (hdr->e_type == ET_DYN)
475 rbase = *addr;
476 else if (hdr->e_type == ET_EXEC)
477 rbase = 0;
478 else {
479 error = ENOEXEC;
480 goto fail;
481 }
482
483 /* Only support headers that fit within first page for now */
484 /* (multiplication of two Elf_Half fields will not overflow) */
485 if ((hdr->e_phoff > PAGE_SIZE) ||
486 (hdr->e_phentsize * hdr->e_phnum) > PAGE_SIZE - hdr->e_phoff) {
487 error = ENOEXEC;
488 goto fail;
489 }
490
491 phdr = (const Elf_Phdr *)(imgp->image_header + hdr->e_phoff);
492 if (!aligned(phdr, Elf_Addr)) {
493 error = ENOEXEC;
494 goto fail;
495 }
496
497 for (i = 0, numsegs = 0; i < hdr->e_phnum; i++) {
498 if (phdr[i].p_type == PT_LOAD && phdr[i].p_memsz != 0) {
499 /* Loadable segment */
500 prot = __elfN(trans_prot)(phdr[i].p_flags);
501 error = __elfN(load_section)(
502 p, vmspace, imgp->vp,
503 phdr[i].p_offset,
504 (caddr_t)phdr[i].p_vaddr +
505 rbase,
506 phdr[i].p_memsz,
507 phdr[i].p_filesz, prot);
508 if (error != 0)
509 goto fail;
510 /*
511 * Establish the base address if this is the
512 * first segment.
513 */
514 if (numsegs == 0)
515 base_addr = trunc_page(phdr[i].p_vaddr + rbase);
516 numsegs++;
517 }
518 }
519 *addr = base_addr;
520 *entry = (unsigned long)hdr->e_entry + rbase;
521
522 fail:
523 if (imgp->firstpage)
524 exec_unmap_first_page(imgp);
525 if (imgp->vp) {
526 vrele(imgp->vp);
527 imgp->vp = NULL;
528 }
529 kfree(tempdata, M_TEMP);
530
531 return (error);
532 }
533
534 static Elf_Brandinfo *
__elfN(get_brandinfo)535 __elfN(get_brandinfo)(struct image_params *imgp, const char *interp,
536 int32_t *osrel)
537 {
538 const Elf_Ehdr *hdr = (const Elf_Ehdr *)imgp->image_header;
539 Elf_Brandinfo *bi;
540 boolean_t ret;
541 int i;
542
543 /* We support four types of branding -- (1) the ELF EI_OSABI field
544 * that SCO added to the ELF spec, (2) FreeBSD 3.x's traditional string
545 * branding within the ELF header, (3) path of the `interp_path' field,
546 * and (4) the ".note.ABI-tag" ELF section.
547 */
548
549 /* Look for an ".note.ABI-tag" ELF section */
550 for (i = 0; i < MAX_BRANDS; i++) {
551 bi = elf_brand_list[i];
552
553 if (bi == NULL)
554 continue;
555 if (hdr->e_machine == bi->machine && (bi->flags &
556 (BI_BRAND_NOTE|BI_BRAND_NOTE_MANDATORY)) != 0) {
557 ret = __elfN(check_note)(imgp, bi->brand_note, osrel);
558 if (ret)
559 return (bi);
560 }
561 }
562
563 /* If the executable has a brand, search for it in the brand list. */
564 for (i = 0; i < MAX_BRANDS; i++) {
565 bi = elf_brand_list[i];
566
567 if (bi == NULL || bi->flags & BI_BRAND_NOTE_MANDATORY)
568 continue;
569 if (hdr->e_machine == bi->machine &&
570 (hdr->e_ident[EI_OSABI] == bi->brand ||
571 strncmp((const char *)&hdr->e_ident[OLD_EI_BRAND],
572 bi->compat_3_brand, strlen(bi->compat_3_brand)) == 0))
573 return (bi);
574 }
575
576 /* Lacking a known brand, search for a recognized interpreter. */
577 if (interp != NULL) {
578 for (i = 0; i < MAX_BRANDS; i++) {
579 bi = elf_brand_list[i];
580
581 if (bi == NULL || bi->flags & BI_BRAND_NOTE_MANDATORY)
582 continue;
583 if (hdr->e_machine == bi->machine &&
584 strcmp(interp, bi->interp_path) == 0)
585 return (bi);
586 }
587 }
588
589 /* Lacking a recognized interpreter, try the default brand */
590 for (i = 0; i < MAX_BRANDS; i++) {
591 bi = elf_brand_list[i];
592
593 if (bi == NULL || bi->flags & BI_BRAND_NOTE_MANDATORY)
594 continue;
595 if (hdr->e_machine == bi->machine &&
596 __elfN(fallback_brand) == bi->brand)
597 return (bi);
598 }
599 return (NULL);
600 }
601
602 static int
__CONCAT(exec_,__elfN (imgact))603 __CONCAT(exec_,__elfN(imgact))(struct image_params *imgp)
604 {
605 const Elf_Ehdr *hdr = (const Elf_Ehdr *) imgp->image_header;
606 const Elf_Phdr *phdr;
607 Elf_Auxargs *elf_auxargs;
608 struct vmspace *vmspace;
609 vm_prot_t prot;
610 u_long text_size = 0, data_size = 0, total_size = 0;
611 u_long text_addr = 0, data_addr = 0;
612 u_long seg_size, seg_addr;
613 u_long addr, baddr, et_dyn_addr = 0, entry = 0, proghdr = 0;
614 int32_t osrel = 0;
615 int error = 0, i, n;
616 boolean_t failure;
617 char *interp = NULL;
618 const char *newinterp = NULL;
619 Elf_Brandinfo *brand_info;
620 char *path;
621
622 /*
623 * Do we have a valid ELF header ?
624 *
625 * Only allow ET_EXEC & ET_DYN here, reject ET_DYN later if a particular
626 * brand doesn't support it. Both DragonFly platforms do by default.
627 */
628 if (__elfN(check_header)(hdr) != 0 ||
629 (hdr->e_type != ET_EXEC && hdr->e_type != ET_DYN))
630 return (-1);
631
632 /*
633 * From here on down, we return an errno, not -1, as we've
634 * detected an ELF file.
635 */
636
637 if ((hdr->e_phoff > PAGE_SIZE) ||
638 (hdr->e_phoff + hdr->e_phentsize * hdr->e_phnum) > PAGE_SIZE) {
639 /* Only support headers in first page for now */
640 return (ENOEXEC);
641 }
642 phdr = (const Elf_Phdr *)(imgp->image_header + hdr->e_phoff);
643 if (!aligned(phdr, Elf_Addr))
644 return (ENOEXEC);
645 n = 0;
646 baddr = 0;
647 for (i = 0; i < hdr->e_phnum; i++) {
648 if (phdr[i].p_type == PT_LOAD) {
649 if (n == 0)
650 baddr = phdr[i].p_vaddr;
651 n++;
652 continue;
653 }
654 if (phdr[i].p_type == PT_INTERP) {
655 /*
656 * If interp is already defined there are more than
657 * one PT_INTERP program headers present. Take only
658 * the first one and ignore the rest.
659 */
660 if (interp != NULL)
661 continue;
662
663 if (phdr[i].p_filesz == 0 ||
664 phdr[i].p_filesz > PAGE_SIZE ||
665 phdr[i].p_filesz > MAXPATHLEN)
666 return (ENOEXEC);
667
668 interp = kmalloc(phdr[i].p_filesz, M_TEMP, M_WAITOK);
669 failure = extract_interpreter(imgp, &phdr[i], interp);
670 if (failure) {
671 kfree(interp, M_TEMP);
672 return (ENOEXEC);
673 }
674 continue;
675 }
676 }
677
678 brand_info = __elfN(get_brandinfo)(imgp, interp, &osrel);
679 if (brand_info == NULL) {
680 uprintf("ELF binary type \"%u\" not known.\n",
681 hdr->e_ident[EI_OSABI]);
682 if (interp != NULL)
683 kfree(interp, M_TEMP);
684 return (ENOEXEC);
685 }
686 if (hdr->e_type == ET_DYN) {
687 if ((brand_info->flags & BI_CAN_EXEC_DYN) == 0) {
688 if (interp != NULL)
689 kfree(interp, M_TEMP);
690 return (ENOEXEC);
691 }
692 /*
693 * If p_vaddr field of PT_LOAD program header is zero and type of an
694 * executale is ET_DYN, then it must be a position independent
695 * executable (PIE). In this case the system needs to pick a base
696 * address for us. Set et_dyn_addr to non-zero and choose the actual
697 * address when we are ready.
698 */
699 if (baddr == 0)
700 et_dyn_addr = 1;
701 }
702
703 if (interp != NULL && brand_info->interp_newpath != NULL)
704 newinterp = brand_info->interp_newpath;
705
706 exec_new_vmspace(imgp, NULL);
707
708 /*
709 * Yeah, I'm paranoid. There is every reason in the world to get
710 * VTEXT now since from here on out, there are places we can have
711 * a context switch. Better safe than sorry; I really don't want
712 * the file to change while it's being loaded.
713 */
714 vsetflags(imgp->vp, VTEXT);
715
716 vmspace = imgp->proc->p_vmspace;
717 /* Choose the base address for dynamic executables if we need to. */
718 if (et_dyn_addr)
719 et_dyn_addr = pie_base_hint(imgp->proc);
720
721 for (i = 0; i < hdr->e_phnum; i++) {
722 switch (phdr[i].p_type) {
723 case PT_LOAD: /* Loadable segment */
724 if (phdr[i].p_memsz == 0)
725 break;
726 prot = __elfN(trans_prot)(phdr[i].p_flags);
727
728 if ((error = __elfN(load_section)(
729 imgp->proc,
730 vmspace,
731 imgp->vp,
732 phdr[i].p_offset,
733 (caddr_t)phdr[i].p_vaddr + et_dyn_addr,
734 phdr[i].p_memsz,
735 phdr[i].p_filesz,
736 prot)) != 0) {
737 if (interp != NULL)
738 kfree (interp, M_TEMP);
739 return (error);
740 }
741
742 /*
743 * If this segment contains the program headers,
744 * remember their virtual address for the AT_PHDR
745 * aux entry. Static binaries don't usually include
746 * a PT_PHDR entry.
747 */
748 if (phdr[i].p_offset == 0 &&
749 hdr->e_phoff + hdr->e_phnum * hdr->e_phentsize
750 <= phdr[i].p_filesz)
751 proghdr = phdr[i].p_vaddr + hdr->e_phoff +
752 et_dyn_addr;
753
754 seg_addr = trunc_page(phdr[i].p_vaddr + et_dyn_addr);
755 seg_size = round_page(phdr[i].p_memsz +
756 phdr[i].p_vaddr + et_dyn_addr - seg_addr);
757
758 /*
759 * Is this .text or .data? We can't use
760 * VM_PROT_WRITE or VM_PROT_EXEC, it breaks the
761 * alpha terribly and possibly does other bad
762 * things so we stick to the old way of figuring
763 * it out: If the segment contains the program
764 * entry point, it's a text segment, otherwise it
765 * is a data segment.
766 *
767 * Note that obreak() assumes that data_addr +
768 * data_size == end of data load area, and the ELF
769 * file format expects segments to be sorted by
770 * address. If multiple data segments exist, the
771 * last one will be used.
772 */
773 if (hdr->e_entry >= phdr[i].p_vaddr &&
774 hdr->e_entry < (phdr[i].p_vaddr +
775 phdr[i].p_memsz)) {
776 text_size = seg_size;
777 text_addr = seg_addr;
778 entry = (u_long)hdr->e_entry + et_dyn_addr;
779 } else {
780 data_size = seg_size;
781 data_addr = seg_addr;
782 }
783 total_size += seg_size;
784
785 /*
786 * Check limits. It should be safe to check the
787 * limits after loading the segment since we do
788 * not actually fault in all the segment's pages.
789 */
790 if (data_size >
791 imgp->proc->p_rlimit[RLIMIT_DATA].rlim_cur ||
792 text_size > maxtsiz ||
793 total_size >
794 imgp->proc->p_rlimit[RLIMIT_VMEM].rlim_cur) {
795 if (interp != NULL)
796 kfree(interp, M_TEMP);
797 error = ENOMEM;
798 return (error);
799 }
800 break;
801 case PT_PHDR: /* Program header table info */
802 proghdr = phdr[i].p_vaddr + et_dyn_addr;
803 break;
804 default:
805 break;
806 }
807 }
808
809 vmspace->vm_tsize = text_size; /* in bytes */
810 vmspace->vm_taddr = (caddr_t)(uintptr_t)text_addr;
811 vmspace->vm_dsize = data_size; /* in bytes */
812 vmspace->vm_daddr = (caddr_t)(uintptr_t)data_addr;
813
814 addr = ELF_RTLD_ADDR(vmspace);
815
816 imgp->entry_addr = entry;
817
818 imgp->proc->p_sysent = brand_info->sysvec;
819
820 if (interp != NULL) {
821 int have_interp = FALSE;
822 if (brand_info->emul_path != NULL &&
823 brand_info->emul_path[0] != '\0') {
824 path = kmalloc(MAXPATHLEN, M_TEMP, M_WAITOK);
825 ksnprintf(path, MAXPATHLEN, "%s%s",
826 brand_info->emul_path, interp);
827 error = __elfN(load_file)(imgp->proc, path, &addr,
828 &imgp->entry_addr);
829 kfree(path, M_TEMP);
830 if (error == 0)
831 have_interp = TRUE;
832 }
833 if (!have_interp && newinterp != NULL) {
834 error = __elfN(load_file)(imgp->proc, newinterp,
835 &addr, &imgp->entry_addr);
836 if (error == 0)
837 have_interp = TRUE;
838 }
839 if (!have_interp) {
840 error = __elfN(load_file)(imgp->proc, interp, &addr,
841 &imgp->entry_addr);
842 }
843 if (error != 0) {
844 uprintf("ELF interpreter %s not found\n", interp);
845 kfree(interp, M_TEMP);
846 return (error);
847 }
848 kfree(interp, M_TEMP);
849 } else
850 addr = et_dyn_addr;
851
852 /*
853 * Construct auxargs table (used by the fixup routine)
854 */
855 elf_auxargs = kmalloc(sizeof(Elf_Auxargs), M_TEMP, M_WAITOK);
856 elf_auxargs->execfd = -1;
857 elf_auxargs->phdr = proghdr;
858 elf_auxargs->phent = hdr->e_phentsize;
859 elf_auxargs->phnum = hdr->e_phnum;
860 elf_auxargs->pagesz = PAGE_SIZE;
861 elf_auxargs->base = addr;
862 elf_auxargs->flags = 0;
863 elf_auxargs->entry = entry;
864
865 imgp->auxargs = elf_auxargs;
866 imgp->interpreted = 0;
867 imgp->proc->p_osrel = osrel;
868
869 return (error);
870 }
871
872 int
__elfN(dragonfly_fixup)873 __elfN(dragonfly_fixup)(register_t **stack_base, struct image_params *imgp)
874 {
875 Elf_Auxargs *args = (Elf_Auxargs *)imgp->auxargs;
876 Elf_Addr *base;
877 Elf_Addr *pos;
878
879 base = (Elf_Addr *)*stack_base;
880 pos = base + (imgp->args->argc + imgp->args->envc + 2);
881
882 if (args->execfd != -1)
883 AUXARGS_ENTRY(pos, AT_EXECFD, args->execfd);
884 AUXARGS_ENTRY(pos, AT_PHDR, args->phdr);
885 AUXARGS_ENTRY(pos, AT_PHENT, args->phent);
886 AUXARGS_ENTRY(pos, AT_PHNUM, args->phnum);
887 AUXARGS_ENTRY(pos, AT_PAGESZ, args->pagesz);
888 AUXARGS_ENTRY(pos, AT_FLAGS, args->flags);
889 AUXARGS_ENTRY(pos, AT_ENTRY, args->entry);
890 AUXARGS_ENTRY(pos, AT_BASE, args->base);
891 if (imgp->execpathp != 0)
892 AUXARGS_ENTRY(pos, AT_EXECPATH, imgp->execpathp);
893 AUXARGS_ENTRY(pos, AT_OSRELDATE, osreldate);
894 AUXARGS_ENTRY(pos, AT_NULL, 0);
895
896 kfree(imgp->auxargs, M_TEMP);
897 imgp->auxargs = NULL;
898
899 base--;
900 suword64(base, (long)imgp->args->argc);
901 *stack_base = (register_t *)base;
902 return (0);
903 }
904
905 /*
906 * Code for generating ELF core dumps.
907 */
908
909 typedef int (*segment_callback)(vm_map_entry_t, void *);
910
911 /* Closure for cb_put_phdr(). */
912 struct phdr_closure {
913 Elf_Phdr *phdr; /* Program header to fill in (incremented) */
914 Elf_Phdr *phdr_max; /* Pointer bound for error check */
915 Elf_Off offset; /* Offset of segment in core file */
916 };
917
918 /* Closure for cb_size_segment(). */
919 struct sseg_closure {
920 int count; /* Count of writable segments. */
921 size_t vsize; /* Total size of all writable segments. */
922 };
923
924 /* Closure for cb_put_fp(). */
925 struct fp_closure {
926 struct vn_hdr *vnh;
927 struct vn_hdr *vnh_max;
928 int count;
929 struct stat *sb;
930 };
931
932 typedef struct elf_buf {
933 char *buf;
934 size_t off;
935 size_t off_max;
936 } *elf_buf_t;
937
938 static void *target_reserve(elf_buf_t target, size_t bytes, int *error);
939
940 static int cb_put_phdr (vm_map_entry_t, void *);
941 static int cb_size_segment (vm_map_entry_t, void *);
942 static int cb_fpcount_segment(vm_map_entry_t, void *);
943 static int cb_put_fp(vm_map_entry_t, void *);
944
945
946 static int each_segment (struct proc *, segment_callback, void *, int);
947 static int __elfN(corehdr)(struct lwp *, int, struct file *, struct ucred *,
948 int, elf_buf_t);
949 enum putmode { WRITE, DRYRUN };
950 static int __elfN(puthdr)(struct lwp *, elf_buf_t, int sig, enum putmode,
951 int, struct file *);
952 static int elf_putallnotes(struct lwp *, elf_buf_t, int, enum putmode);
953 static int __elfN(putnote)(elf_buf_t, const char *, int, const void *, size_t);
954
955 static int elf_putsigs(struct lwp *, elf_buf_t);
956 static int elf_puttextvp(struct proc *, elf_buf_t);
957 static int elf_putfiles(struct proc *, elf_buf_t, struct file *);
958
959 int
__elfN(coredump)960 __elfN(coredump)(struct lwp *lp, int sig, struct vnode *vp, off_t limit)
961 {
962 struct file *fp;
963 int error;
964
965 if ((error = falloc(NULL, &fp, NULL)) != 0)
966 return (error);
967 fsetcred(fp, lp->lwp_proc->p_ucred);
968
969 /*
970 * XXX fixme.
971 */
972 fp->f_type = DTYPE_VNODE;
973 fp->f_flag = O_CREAT|O_WRONLY|O_NOFOLLOW;
974 fp->f_ops = &vnode_fileops;
975 fp->f_data = vp;
976
977 error = generic_elf_coredump(lp, sig, fp, limit);
978
979 fp->f_type = 0;
980 fp->f_flag = 0;
981 fp->f_ops = &badfileops;
982 fp->f_data = NULL;
983 fdrop(fp);
984 return (error);
985 }
986
987 int
generic_elf_coredump(struct lwp * lp,int sig,struct file * fp,off_t limit)988 generic_elf_coredump(struct lwp *lp, int sig, struct file *fp, off_t limit)
989 {
990 struct proc *p = lp->lwp_proc;
991 struct ucred *cred = p->p_ucred;
992 int error = 0;
993 struct sseg_closure seginfo;
994 struct elf_buf target;
995
996 if (!fp)
997 kprintf("can't dump core - null fp\n");
998
999 /*
1000 * Size the program segments
1001 */
1002 seginfo.count = 0;
1003 seginfo.vsize = 0;
1004 each_segment(p, cb_size_segment, &seginfo, 1);
1005
1006 /*
1007 * Calculate the size of the core file header area by making
1008 * a dry run of generating it. Nothing is written, but the
1009 * size is calculated.
1010 */
1011 bzero(&target, sizeof(target));
1012 __elfN(puthdr)(lp, &target, sig, DRYRUN, seginfo.count, fp);
1013
1014 if (target.off + seginfo.vsize >= limit)
1015 return (EFAULT);
1016
1017 /*
1018 * Allocate memory for building the header, fill it up,
1019 * and write it out.
1020 */
1021 target.off_max = target.off;
1022 target.off = 0;
1023 target.buf = kmalloc(target.off_max, M_TEMP, M_WAITOK|M_ZERO);
1024
1025 error = __elfN(corehdr)(lp, sig, fp, cred, seginfo.count, &target);
1026
1027 /* Write the contents of all of the writable segments. */
1028 if (error == 0) {
1029 Elf_Phdr *php;
1030 int i;
1031 ssize_t nbytes;
1032
1033 php = (Elf_Phdr *)(target.buf + sizeof(Elf_Ehdr)) + 1;
1034 for (i = 0; i < seginfo.count; i++) {
1035 error = fp_write(fp, (caddr_t)php->p_vaddr,
1036 php->p_filesz, &nbytes, UIO_USERSPACE);
1037 if (error != 0)
1038 break;
1039 if (p->p_flags & P_MUSTKILL) {
1040 error = EIO;
1041 break;
1042 }
1043 php++;
1044 }
1045 }
1046 kfree(target.buf, M_TEMP);
1047
1048 return (error);
1049 }
1050
1051 /*
1052 * A callback for each_segment() to write out the segment's
1053 * program header entry.
1054 */
1055 static int
cb_put_phdr(vm_map_entry_t entry,void * closure)1056 cb_put_phdr(vm_map_entry_t entry, void *closure)
1057 {
1058 struct phdr_closure *phc = closure;
1059 Elf_Phdr *phdr = phc->phdr;
1060
1061 if (phc->phdr == phc->phdr_max)
1062 return (EINVAL);
1063
1064 phc->offset = round_page(phc->offset);
1065
1066 phdr->p_type = PT_LOAD;
1067 phdr->p_offset = phc->offset;
1068 phdr->p_vaddr = entry->ba.start;
1069 phdr->p_paddr = 0;
1070 phdr->p_filesz = phdr->p_memsz = entry->ba.end - entry->ba.start;
1071 phdr->p_align = PAGE_SIZE;
1072 phdr->p_flags = __elfN(untrans_prot)(entry->protection);
1073
1074 phc->offset += phdr->p_filesz;
1075 ++phc->phdr;
1076 return (0);
1077 }
1078
1079 /*
1080 * A callback for each_writable_segment() to gather information about
1081 * the number of segments and their total size.
1082 */
1083 static int
cb_size_segment(vm_map_entry_t entry,void * closure)1084 cb_size_segment(vm_map_entry_t entry, void *closure)
1085 {
1086 struct sseg_closure *ssc = closure;
1087
1088 ++ssc->count;
1089 ssc->vsize += entry->ba.end - entry->ba.start;
1090 return (0);
1091 }
1092
1093 /*
1094 * A callback for each_segment() to gather information about
1095 * the number of text segments.
1096 */
1097 static int
cb_fpcount_segment(vm_map_entry_t entry,void * closure)1098 cb_fpcount_segment(vm_map_entry_t entry, void *closure)
1099 {
1100 int *count = closure;
1101 struct vnode *vp;
1102
1103 if (entry->ba.object && entry->ba.object->type == OBJT_VNODE) {
1104 vp = (struct vnode *)entry->ba.object->handle;
1105 if ((vp->v_flag & VCKPT) && curproc->p_textvp == vp)
1106 return (0);
1107 ++*count;
1108 }
1109 return (0);
1110 }
1111
1112 static int
cb_put_fp(vm_map_entry_t entry,void * closure)1113 cb_put_fp(vm_map_entry_t entry, void *closure)
1114 {
1115 struct fp_closure *fpc = closure;
1116 struct vn_hdr *vnh = fpc->vnh;
1117 Elf_Phdr *phdr = &vnh->vnh_phdr;
1118 struct vnode *vp;
1119 int error;
1120
1121 /*
1122 * If an entry represents a vnode then write out a file handle.
1123 *
1124 * If we are checkpointing a checkpoint-restored program we do
1125 * NOT record the filehandle for the old checkpoint vnode (which
1126 * is mapped all over the place). Instead we rely on the fact
1127 * that a checkpoint-restored program does not mmap() the checkpt
1128 * vnode NOCORE, so its contents will be written out to the
1129 * new checkpoint file. This is necessary because the 'old'
1130 * checkpoint file is typically destroyed when a new one is created
1131 * and thus cannot be used to restore the new checkpoint.
1132 *
1133 * Theoretically we could create a chain of checkpoint files and
1134 * operate the checkpointing operation kinda like an incremental
1135 * checkpoint, but a checkpoint restore would then likely wind up
1136 * referencing many prior checkpoint files and that is a bit over
1137 * the top for the purpose of the checkpoint API.
1138 */
1139 if (entry->ba.object && entry->ba.object->type == OBJT_VNODE) {
1140 vp = (struct vnode *)entry->ba.object->handle;
1141 if ((vp->v_flag & VCKPT) && curproc->p_textvp == vp)
1142 return (0);
1143 if (vnh == fpc->vnh_max)
1144 return (EINVAL);
1145
1146 if (vp->v_mount)
1147 vnh->vnh_fh.fh_fsid = vp->v_mount->mnt_stat.f_fsid;
1148 error = VFS_VPTOFH(vp, &vnh->vnh_fh.fh_fid);
1149 if (error) {
1150 char *freepath, *fullpath;
1151
1152 /*
1153 * This is actually a relatively common occurance,
1154 * so don't spew on the console by default.
1155 */
1156 if (vn_fullpath(curproc, vp, &fullpath, &freepath, 0)) {
1157 if (bootverbose)
1158 kprintf("Warning: coredump, error %d: cannot store file handle for vnode %p\n", error, vp);
1159 } else {
1160 if (bootverbose)
1161 kprintf("Warning: coredump, error %d: cannot store file handle for %s\n", error, fullpath);
1162 kfree(freepath, M_TEMP);
1163 }
1164 error = 0;
1165 }
1166
1167 phdr->p_type = PT_LOAD;
1168 phdr->p_offset = 0; /* not written to core */
1169 phdr->p_vaddr = entry->ba.start;
1170 phdr->p_paddr = 0;
1171 phdr->p_filesz = phdr->p_memsz =
1172 entry->ba.end - entry->ba.start;
1173 phdr->p_align = PAGE_SIZE;
1174 phdr->p_flags = 0;
1175 if (entry->protection & VM_PROT_READ)
1176 phdr->p_flags |= PF_R;
1177 if (entry->protection & VM_PROT_WRITE)
1178 phdr->p_flags |= PF_W;
1179 if (entry->protection & VM_PROT_EXECUTE)
1180 phdr->p_flags |= PF_X;
1181 ++fpc->vnh;
1182 ++fpc->count;
1183 }
1184 return (0);
1185 }
1186
1187 /*
1188 * For each writable segment in the process's memory map, call the given
1189 * function with a pointer to the map entry and some arbitrary
1190 * caller-supplied data.
1191 */
1192 static int
each_segment(struct proc * p,segment_callback func,void * closure,int writable)1193 each_segment(struct proc *p, segment_callback func, void *closure, int writable)
1194 {
1195 int error = 0;
1196 vm_map_t map = &p->p_vmspace->vm_map;
1197 vm_map_entry_t entry;
1198
1199 RB_FOREACH(entry, vm_map_rb_tree, &map->rb_root) {
1200 vm_map_backing_t ba;
1201 vm_object_t obj;
1202
1203 /*
1204 * Don't dump inaccessible mappings, deal with legacy
1205 * coredump mode.
1206 *
1207 * Note that read-only segments related to the elf binary
1208 * are marked MAP_ENTRY_NOCOREDUMP now so we no longer
1209 * need to arbitrarily ignore such segments.
1210 */
1211 if (elf_legacy_coredump) {
1212 if (writable && (entry->protection & VM_PROT_RW) != VM_PROT_RW)
1213 continue;
1214 } else {
1215 if (writable && (entry->protection & VM_PROT_ALL) == 0)
1216 continue;
1217 }
1218
1219 /*
1220 * Dont include memory segment in the coredump if
1221 * MAP_NOCORE is set in mmap(2) or MADV_NOCORE in
1222 * madvise(2).
1223 *
1224 * Currently we only dump normal VM object maps. We do
1225 * not dump submaps or virtual page tables.
1226 */
1227 if (writable && (entry->eflags & MAP_ENTRY_NOCOREDUMP))
1228 continue;
1229 if (entry->maptype != VM_MAPTYPE_NORMAL)
1230 continue;
1231
1232 /*
1233 * Find the bottom-most object, leaving the base object
1234 * and the bottom-most object held (but only one hold
1235 * if they happen to be the same).
1236 */
1237 ba = &entry->ba;
1238 while (ba->backing_ba)
1239 ba = ba->backing_ba;
1240 obj = ba->object;
1241
1242 /*
1243 * The callback only applies to default, swap, or vnode
1244 * objects. Other types of objects such as memory-mapped
1245 * devices are ignored.
1246 */
1247 if (obj) {
1248 vm_object_hold_shared(obj);
1249
1250 if (obj->type == OBJT_DEFAULT ||
1251 obj->type == OBJT_SWAP ||
1252 obj->type == OBJT_VNODE) {
1253 error = (*func)(entry, closure);
1254 }
1255 vm_object_drop(obj);
1256 }
1257 }
1258 return (error);
1259 }
1260
1261 static
1262 void *
target_reserve(elf_buf_t target,size_t bytes,int * error)1263 target_reserve(elf_buf_t target, size_t bytes, int *error)
1264 {
1265 void *res = NULL;
1266
1267 if (target->buf) {
1268 if (target->off + bytes > target->off_max)
1269 *error = EINVAL;
1270 else
1271 res = target->buf + target->off;
1272 }
1273 target->off += bytes;
1274 return (res);
1275 }
1276
1277 /*
1278 * Write the core file header to the file, including padding up to
1279 * the page boundary.
1280 */
1281 static int
__elfN(corehdr)1282 __elfN(corehdr)(struct lwp *lp, int sig, struct file *fp, struct ucred *cred,
1283 int numsegs, elf_buf_t target)
1284 {
1285 int error;
1286 ssize_t nbytes;
1287
1288 /*
1289 * Fill in the header. The fp is passed so we can detect and flag
1290 * a checkpoint file pointer within the core file itself, because
1291 * it may not be restored from the same file handle.
1292 */
1293 error = __elfN(puthdr)(lp, target, sig, WRITE, numsegs, fp);
1294
1295 /* Write it to the core file. */
1296 if (error == 0) {
1297 error = fp_write(fp, target->buf, target->off, &nbytes,
1298 UIO_SYSSPACE);
1299 }
1300 return (error);
1301 }
1302
1303 static int
__elfN(puthdr)1304 __elfN(puthdr)(struct lwp *lp, elf_buf_t target, int sig, enum putmode mode,
1305 int numsegs, struct file *fp)
1306 {
1307 struct proc *p = lp->lwp_proc;
1308 int error = 0;
1309 size_t phoff;
1310 size_t noteoff;
1311 size_t notesz;
1312 Elf_Ehdr *ehdr;
1313 Elf_Phdr *phdr;
1314
1315 ehdr = target_reserve(target, sizeof(Elf_Ehdr), &error);
1316
1317 phoff = target->off;
1318 phdr = target_reserve(target, (numsegs + 1) * sizeof(Elf_Phdr), &error);
1319
1320 noteoff = target->off;
1321 if (error == 0)
1322 elf_putallnotes(lp, target, sig, mode);
1323 notesz = target->off - noteoff;
1324
1325 /*
1326 * put extra cruft for dumping process state here
1327 * - we really want it be before all the program
1328 * mappings
1329 * - we just need to update the offset accordingly
1330 * and GDB will be none the wiser.
1331 */
1332 if (error == 0)
1333 error = elf_puttextvp(p, target);
1334 if (error == 0)
1335 error = elf_putsigs(lp, target);
1336 if (error == 0)
1337 error = elf_putfiles(p, target, fp);
1338
1339 /*
1340 * Align up to a page boundary for the program segments. The
1341 * actual data will be written to the outptu file, not to elf_buf_t,
1342 * so we do not have to do any further bounds checking.
1343 */
1344 target->off = round_page(target->off);
1345 if (error == 0 && ehdr != NULL) {
1346 /*
1347 * Fill in the ELF header.
1348 */
1349 ehdr->e_ident[EI_MAG0] = ELFMAG0;
1350 ehdr->e_ident[EI_MAG1] = ELFMAG1;
1351 ehdr->e_ident[EI_MAG2] = ELFMAG2;
1352 ehdr->e_ident[EI_MAG3] = ELFMAG3;
1353 ehdr->e_ident[EI_CLASS] = ELF_CLASS;
1354 ehdr->e_ident[EI_DATA] = ELF_DATA;
1355 ehdr->e_ident[EI_VERSION] = EV_CURRENT;
1356 ehdr->e_ident[EI_OSABI] = ELFOSABI_NONE;
1357 ehdr->e_ident[EI_ABIVERSION] = 0;
1358 ehdr->e_ident[EI_PAD] = 0;
1359 ehdr->e_type = ET_CORE;
1360 ehdr->e_machine = ELF_ARCH;
1361 ehdr->e_version = EV_CURRENT;
1362 ehdr->e_entry = 0;
1363 ehdr->e_phoff = phoff;
1364 ehdr->e_flags = 0;
1365 ehdr->e_ehsize = sizeof(Elf_Ehdr);
1366 ehdr->e_phentsize = sizeof(Elf_Phdr);
1367 ehdr->e_phnum = numsegs + 1;
1368 ehdr->e_shentsize = sizeof(Elf_Shdr);
1369 ehdr->e_shnum = 0;
1370 ehdr->e_shstrndx = SHN_UNDEF;
1371 }
1372 if (error == 0 && phdr != NULL) {
1373 /*
1374 * Fill in the program header entries.
1375 */
1376 struct phdr_closure phc;
1377
1378 /* The note segement. */
1379 phdr->p_type = PT_NOTE;
1380 phdr->p_offset = noteoff;
1381 phdr->p_vaddr = 0;
1382 phdr->p_paddr = 0;
1383 phdr->p_filesz = notesz;
1384 phdr->p_memsz = 0;
1385 phdr->p_flags = 0;
1386 phdr->p_align = 0;
1387 ++phdr;
1388
1389 /* All the writable segments from the program. */
1390 phc.phdr = phdr;
1391 phc.phdr_max = phdr + numsegs;
1392 phc.offset = target->off;
1393 each_segment(p, cb_put_phdr, &phc, 1);
1394 }
1395 return (error);
1396 }
1397
1398 /*
1399 * Append core dump notes to target ELF buffer or simply update target size
1400 * if dryrun selected.
1401 */
1402 static int
elf_putallnotes(struct lwp * corelp,elf_buf_t target,int sig,enum putmode mode)1403 elf_putallnotes(struct lwp *corelp, elf_buf_t target, int sig,
1404 enum putmode mode)
1405 {
1406 struct proc *p = corelp->lwp_proc;
1407 int error;
1408 struct {
1409 prstatus_t status;
1410 prfpregset_t fpregs;
1411 prpsinfo_t psinfo;
1412 } *tmpdata;
1413 prstatus_t *status;
1414 prfpregset_t *fpregs;
1415 prpsinfo_t *psinfo;
1416 struct lwp *lp;
1417
1418 /*
1419 * Allocate temporary storage for notes on heap to avoid stack overflow.
1420 */
1421 if (mode != DRYRUN) {
1422 tmpdata = kmalloc(sizeof(*tmpdata), M_TEMP, M_ZERO | M_WAITOK);
1423 status = &tmpdata->status;
1424 fpregs = &tmpdata->fpregs;
1425 psinfo = &tmpdata->psinfo;
1426 } else {
1427 tmpdata = NULL;
1428 status = NULL;
1429 fpregs = NULL;
1430 psinfo = NULL;
1431 }
1432
1433 /*
1434 * Append LWP-agnostic note.
1435 */
1436 if (mode != DRYRUN) {
1437 psinfo->pr_version = PRPSINFO_VERSION;
1438 psinfo->pr_psinfosz = sizeof(prpsinfo_t);
1439 strlcpy(psinfo->pr_fname, p->p_comm,
1440 sizeof(psinfo->pr_fname));
1441 /*
1442 * XXX - We don't fill in the command line arguments
1443 * properly yet.
1444 */
1445 strlcpy(psinfo->pr_psargs, p->p_comm,
1446 sizeof(psinfo->pr_psargs));
1447 }
1448 error =
1449 __elfN(putnote)(target, "CORE", NT_PRPSINFO, psinfo, sizeof *psinfo);
1450 if (error)
1451 goto exit;
1452
1453 /*
1454 * Append first note for LWP that triggered core so that it is
1455 * the selected one when the debugger starts.
1456 */
1457 if (mode != DRYRUN) {
1458 status->pr_version = PRSTATUS_VERSION;
1459 status->pr_statussz = sizeof(prstatus_t);
1460 status->pr_gregsetsz = sizeof(gregset_t);
1461 status->pr_fpregsetsz = sizeof(fpregset_t);
1462 status->pr_osreldate = osreldate;
1463 status->pr_cursig = sig;
1464 status->pr_pid = corelp->lwp_tid;
1465 fill_regs(corelp, &status->pr_reg);
1466 fill_fpregs(corelp, fpregs);
1467 }
1468 error =
1469 __elfN(putnote)(target, "CORE", NT_PRSTATUS, status, sizeof *status);
1470 if (error)
1471 goto exit;
1472 error =
1473 __elfN(putnote)(target, "CORE", NT_FPREGSET, fpregs, sizeof *fpregs);
1474 if (error)
1475 goto exit;
1476
1477 /*
1478 * Then append notes for other LWPs.
1479 */
1480 FOREACH_LWP_IN_PROC(lp, p) {
1481 if (lp == corelp)
1482 continue;
1483 /* skip lwps being created */
1484 if (lp->lwp_thread == NULL)
1485 continue;
1486 if (mode != DRYRUN) {
1487 status->pr_pid = lp->lwp_tid;
1488 fill_regs(lp, &status->pr_reg);
1489 fill_fpregs(lp, fpregs);
1490 }
1491 error = __elfN(putnote)(target, "CORE", NT_PRSTATUS,
1492 status, sizeof *status);
1493 if (error)
1494 goto exit;
1495 error = __elfN(putnote)(target, "CORE", NT_FPREGSET,
1496 fpregs, sizeof *fpregs);
1497 if (error)
1498 goto exit;
1499 }
1500
1501 exit:
1502 if (tmpdata != NULL)
1503 kfree(tmpdata, M_TEMP);
1504 return (error);
1505 }
1506
1507 /*
1508 * Generate a note sub-structure.
1509 *
1510 * NOTE: 4-byte alignment.
1511 */
1512 static int
__elfN(putnote)1513 __elfN(putnote)(elf_buf_t target, const char *name, int type,
1514 const void *desc, size_t descsz)
1515 {
1516 int error = 0;
1517 char *dst;
1518 Elf_Note note;
1519
1520 note.n_namesz = strlen(name) + 1;
1521 note.n_descsz = descsz;
1522 note.n_type = type;
1523 dst = target_reserve(target, sizeof(note), &error);
1524 if (dst != NULL)
1525 bcopy(¬e, dst, sizeof note);
1526 dst = target_reserve(target, note.n_namesz, &error);
1527 if (dst != NULL)
1528 bcopy(name, dst, note.n_namesz);
1529 target->off = roundup2(target->off, sizeof(Elf_Word));
1530 dst = target_reserve(target, note.n_descsz, &error);
1531 if (dst != NULL)
1532 bcopy(desc, dst, note.n_descsz);
1533 target->off = roundup2(target->off, sizeof(Elf_Word));
1534 return (error);
1535 }
1536
1537
1538 static int
elf_putsigs(struct lwp * lp,elf_buf_t target)1539 elf_putsigs(struct lwp *lp, elf_buf_t target)
1540 {
1541 /* XXX lwp handle more than one lwp */
1542 struct proc *p = lp->lwp_proc;
1543 int error = 0;
1544 struct ckpt_siginfo *csi;
1545
1546 csi = target_reserve(target, sizeof(struct ckpt_siginfo), &error);
1547 if (csi) {
1548 csi->csi_ckptpisz = sizeof(struct ckpt_siginfo);
1549 bcopy(p->p_sigacts, &csi->csi_sigacts, sizeof(*p->p_sigacts));
1550 bcopy(&p->p_realtimer, &csi->csi_itimerval, sizeof(struct itimerval));
1551 bcopy(&lp->lwp_sigmask, &csi->csi_sigmask,
1552 sizeof(sigset_t));
1553 csi->csi_sigparent = p->p_sigparent;
1554 }
1555 return (error);
1556 }
1557
1558 static int
elf_putfiles(struct proc * p,elf_buf_t target,struct file * ckfp)1559 elf_putfiles(struct proc *p, elf_buf_t target, struct file *ckfp)
1560 {
1561 thread_t td = curthread;
1562 int error = 0;
1563 int i;
1564 struct ckpt_filehdr *cfh = NULL;
1565 struct ckpt_fileinfo *cfi;
1566 struct file *fp;
1567 struct vnode *vp;
1568
1569 /*
1570 * the duplicated loop is gross, but it was the only way
1571 * to eliminate uninitialized variable warnings
1572 */
1573 cfh = target_reserve(target, sizeof(struct ckpt_filehdr), &error);
1574 if (cfh) {
1575 cfh->cfh_nfiles = 0;
1576 }
1577
1578 /*
1579 * ignore STDIN/STDERR/STDOUT.
1580 */
1581 KKASSERT(td->td_proc == p);
1582 for (i = 3; error == 0 && i < p->p_fd->fd_nfiles; i++) {
1583 fp = holdfp(td, i, -1);
1584 if (fp == NULL)
1585 continue;
1586 /*
1587 * XXX Only checkpoint vnodes for now.
1588 */
1589 if (fp->f_type != DTYPE_VNODE) {
1590 fdrop(fp);
1591 continue;
1592 }
1593 cfi = target_reserve(target, sizeof(struct ckpt_fileinfo),
1594 &error);
1595 if (cfi == NULL) {
1596 fdrop(fp);
1597 continue;
1598 }
1599 cfi->cfi_index = -1;
1600 cfi->cfi_type = fp->f_type;
1601 cfi->cfi_flags = fp->f_flag;
1602 cfi->cfi_offset = fp->f_offset;
1603 cfi->cfi_ckflags = 0;
1604
1605 if (fp == ckfp)
1606 cfi->cfi_ckflags |= CKFIF_ISCKPTFD;
1607 /* f_count and f_msgcount should not be saved/restored */
1608 /* XXX save cred info */
1609
1610 switch(fp->f_type) {
1611 case DTYPE_VNODE:
1612 vp = (struct vnode *)fp->f_data;
1613 /*
1614 * it looks like a bug in ptrace is marking
1615 * a non-vnode as a vnode - until we find the
1616 * root cause this will at least prevent
1617 * further panics from truss
1618 */
1619 if (vp == NULL || vp->v_mount == NULL)
1620 break;
1621 cfh->cfh_nfiles++;
1622 cfi->cfi_index = i;
1623 cfi->cfi_fh.fh_fsid = vp->v_mount->mnt_stat.f_fsid;
1624 error = VFS_VPTOFH(vp, &cfi->cfi_fh.fh_fid);
1625 break;
1626 default:
1627 break;
1628 }
1629 fdrop(fp);
1630 }
1631 return (error);
1632 }
1633
1634 static int
elf_puttextvp(struct proc * p,elf_buf_t target)1635 elf_puttextvp(struct proc *p, elf_buf_t target)
1636 {
1637 int error = 0;
1638 int *vn_count;
1639 struct fp_closure fpc;
1640 struct ckpt_vminfo *vminfo;
1641
1642 vminfo = target_reserve(target, sizeof(struct ckpt_vminfo), &error);
1643 if (vminfo != NULL) {
1644 vminfo->cvm_dsize = btoc(p->p_vmspace->vm_dsize); /* pages */
1645 vminfo->cvm_tsize = btoc(p->p_vmspace->vm_tsize); /* pages */
1646 vminfo->cvm_daddr = p->p_vmspace->vm_daddr;
1647 vminfo->cvm_taddr = p->p_vmspace->vm_taddr;
1648 }
1649
1650 fpc.count = 0;
1651 vn_count = target_reserve(target, sizeof(int), &error);
1652 if (target->buf != NULL) {
1653 fpc.vnh = (struct vn_hdr *)(target->buf + target->off);
1654 fpc.vnh_max = fpc.vnh +
1655 (target->off_max - target->off) / sizeof(struct vn_hdr);
1656 error = each_segment(p, cb_put_fp, &fpc, 0);
1657 if (vn_count)
1658 *vn_count = fpc.count;
1659 } else {
1660 error = each_segment(p, cb_fpcount_segment, &fpc.count, 0);
1661 }
1662 target->off += fpc.count * sizeof(struct vn_hdr);
1663 return (error);
1664 }
1665
1666 /*
1667 * Try to find the appropriate ABI-note section for checknote,
1668 * The entire image is searched if necessary, not only the first page.
1669 */
1670 static boolean_t
__elfN(check_note)1671 __elfN(check_note)(struct image_params *imgp, Elf_Brandnote *checknote,
1672 int32_t *osrel)
1673 {
1674 boolean_t valid_note_found;
1675 const Elf_Phdr *phdr, *pnote;
1676 const Elf_Ehdr *hdr;
1677 int i;
1678
1679 valid_note_found = FALSE;
1680 hdr = (const Elf_Ehdr *)imgp->image_header;
1681 phdr = (const Elf_Phdr *)(imgp->image_header + hdr->e_phoff);
1682
1683 for (i = 0; i < hdr->e_phnum; i++) {
1684 if (phdr[i].p_type == PT_NOTE) {
1685 pnote = &phdr[i];
1686 valid_note_found = check_PT_NOTE (imgp, checknote,
1687 osrel, pnote);
1688 if (valid_note_found)
1689 break;
1690 }
1691 }
1692 return valid_note_found;
1693 }
1694
1695 /*
1696 * Be careful not to create new overflow conditions when checking
1697 * for overflow.
1698 */
1699 static boolean_t
note_overflow(const Elf_Note * note,size_t maxsize)1700 note_overflow(const Elf_Note *note, size_t maxsize)
1701 {
1702 if (sizeof(*note) > maxsize)
1703 return TRUE;
1704 if (note->n_namesz > maxsize - sizeof(*note))
1705 return TRUE;
1706 return FALSE;
1707 }
1708
1709 static boolean_t
hdr_overflow(__ElfN (Off)off_beg,__ElfN (Size)size)1710 hdr_overflow(__ElfN(Off) off_beg, __ElfN(Size) size)
1711 {
1712 __ElfN(Off) off_end;
1713
1714 off_end = off_beg + size;
1715 if (off_end < off_beg)
1716 return TRUE;
1717 return FALSE;
1718 }
1719
1720 static boolean_t
check_PT_NOTE(struct image_params * imgp,Elf_Brandnote * checknote,int32_t * osrel,const Elf_Phdr * pnote)1721 check_PT_NOTE(struct image_params *imgp, Elf_Brandnote *checknote,
1722 int32_t *osrel, const Elf_Phdr * pnote)
1723 {
1724 boolean_t limited_to_first_page;
1725 boolean_t found = FALSE;
1726 const Elf_Note *note, *note0, *note_end;
1727 const char *note_name;
1728 __ElfN(Off) noteloc, firstloc;
1729 __ElfN(Size) notesz, firstlen, endbyte;
1730 struct lwbuf *lwb;
1731 struct lwbuf lwb_cache;
1732 const char *page;
1733 char *data = NULL;
1734 int n;
1735
1736 if (hdr_overflow(pnote->p_offset, pnote->p_filesz))
1737 return (FALSE);
1738 notesz = pnote->p_filesz;
1739 noteloc = pnote->p_offset;
1740 endbyte = noteloc + notesz;
1741 limited_to_first_page = noteloc < PAGE_SIZE && endbyte < PAGE_SIZE;
1742
1743 if (limited_to_first_page) {
1744 note = (const Elf_Note *)(imgp->image_header + noteloc);
1745 note_end = (const Elf_Note *)(imgp->image_header + endbyte);
1746 note0 = note;
1747 } else {
1748 firstloc = noteloc & PAGE_MASK;
1749 firstlen = PAGE_SIZE - firstloc;
1750 if (notesz < sizeof(Elf_Note) || notesz > PAGE_SIZE)
1751 return (FALSE);
1752
1753 lwb = &lwb_cache;
1754 if (exec_map_page(imgp, noteloc >> PAGE_SHIFT, &lwb, &page))
1755 return (FALSE);
1756 if (firstlen < notesz) { /* crosses page boundary */
1757 data = kmalloc(notesz, M_TEMP, M_WAITOK);
1758 bcopy(page + firstloc, data, firstlen);
1759
1760 exec_unmap_page(lwb);
1761 lwb = &lwb_cache;
1762 if (exec_map_page(imgp, (noteloc >> PAGE_SHIFT) + 1,
1763 &lwb, &page)) {
1764 kfree(data, M_TEMP);
1765 return (FALSE);
1766 }
1767 bcopy(page, data + firstlen, notesz - firstlen);
1768 note = note0 = (const Elf_Note *)(data);
1769 note_end = (const Elf_Note *)(data + notesz);
1770 } else {
1771 note = note0 = (const Elf_Note *)(page + firstloc);
1772 note_end = (const Elf_Note *)(page + firstloc +
1773 firstlen);
1774 }
1775 }
1776
1777 for (n = 0; n < 100 && note >= note0 && note < note_end; n++) {
1778 if (!aligned(note, Elf32_Addr))
1779 break;
1780 if (note_overflow(note, (const char *)note_end -
1781 (const char *)note)) {
1782 break;
1783 }
1784 note_name = (const char *)(note + 1);
1785
1786 if (note->n_namesz == checknote->hdr.n_namesz
1787 && note->n_descsz == checknote->hdr.n_descsz
1788 && note->n_type == checknote->hdr.n_type
1789 && (strncmp(checknote->vendor, note_name,
1790 checknote->hdr.n_namesz) == 0)) {
1791 /* Fetch osreldata from ABI.note-tag */
1792 if ((checknote->flags & BN_TRANSLATE_OSREL) != 0 &&
1793 checknote->trans_osrel != NULL)
1794 checknote->trans_osrel(note, osrel);
1795 found = TRUE;
1796 break;
1797 }
1798 note = (const Elf_Note *)((const char *)(note + 1) +
1799 roundup2(note->n_namesz, sizeof(Elf32_Addr)) +
1800 roundup2(note->n_descsz, sizeof(Elf32_Addr)));
1801 }
1802
1803 if (!limited_to_first_page) {
1804 if (data != NULL)
1805 kfree(data, M_TEMP);
1806 exec_unmap_page(lwb);
1807 }
1808 return (found);
1809 }
1810
1811 /*
1812 * The interpreter program header may be located beyond the first page, so
1813 * regardless of its location, a copy of the interpreter path is created so
1814 * that it may be safely referenced by the calling function in all case. The
1815 * memory is allocated by calling function, and the copying is done here.
1816 */
1817 static boolean_t
extract_interpreter(struct image_params * imgp,const Elf_Phdr * pinterpreter,char * data)1818 extract_interpreter(struct image_params *imgp, const Elf_Phdr *pinterpreter,
1819 char *data)
1820 {
1821 boolean_t limited_to_first_page;
1822 const boolean_t result_success = FALSE;
1823 const boolean_t result_failure = TRUE;
1824 __ElfN(Off) pathloc, firstloc;
1825 __ElfN(Size) pathsz, firstlen, endbyte;
1826 struct lwbuf *lwb;
1827 struct lwbuf lwb_cache;
1828 const char *page;
1829
1830 if (hdr_overflow(pinterpreter->p_offset, pinterpreter->p_filesz))
1831 return (result_failure);
1832 pathsz = pinterpreter->p_filesz;
1833 pathloc = pinterpreter->p_offset;
1834 endbyte = pathloc + pathsz;
1835
1836 limited_to_first_page = pathloc < PAGE_SIZE && endbyte < PAGE_SIZE;
1837 if (limited_to_first_page) {
1838 bcopy(imgp->image_header + pathloc, data, pathsz);
1839 return (result_success);
1840 }
1841
1842 firstloc = pathloc & PAGE_MASK;
1843 firstlen = PAGE_SIZE - firstloc;
1844
1845 lwb = &lwb_cache;
1846 if (exec_map_page(imgp, pathloc >> PAGE_SHIFT, &lwb, &page))
1847 return (result_failure);
1848
1849 if (firstlen < pathsz) { /* crosses page boundary */
1850 bcopy(page + firstloc, data, firstlen);
1851
1852 exec_unmap_page(lwb);
1853 lwb = &lwb_cache;
1854 if (exec_map_page(imgp, (pathloc >> PAGE_SHIFT) + 1, &lwb,
1855 &page))
1856 return (result_failure);
1857 bcopy(page, data + firstlen, pathsz - firstlen);
1858 } else
1859 bcopy(page + firstloc, data, pathsz);
1860
1861 exec_unmap_page(lwb);
1862 return (result_success);
1863 }
1864
1865 static boolean_t
__elfN(bsd_trans_osrel)1866 __elfN(bsd_trans_osrel)(const Elf_Note *note, int32_t *osrel)
1867 {
1868 uintptr_t p;
1869
1870 p = (uintptr_t)(note + 1);
1871 p += roundup2(note->n_namesz, sizeof(Elf32_Addr));
1872 *osrel = *(const int32_t *)(p);
1873
1874 return (TRUE);
1875 }
1876
1877 /*
1878 * Tell kern_execve.c about it, with a little help from the linker.
1879 */
1880 #if defined(__x86_64__)
1881 static struct execsw elf_execsw = {exec_elf64_imgact, "ELF64"};
1882 EXEC_SET_ORDERED(elf64, elf_execsw, SI_ORDER_FIRST);
1883 #else /* i386 assumed */
1884 static struct execsw elf_execsw = {exec_elf32_imgact, "ELF32"};
1885 EXEC_SET_ORDERED(elf32, elf_execsw, SI_ORDER_FIRST);
1886 #endif
1887
1888 static vm_prot_t
__elfN(trans_prot)1889 __elfN(trans_prot)(Elf_Word flags)
1890 {
1891 vm_prot_t prot;
1892
1893 prot = 0;
1894 if (flags & PF_X)
1895 prot |= VM_PROT_EXECUTE;
1896 if (flags & PF_W)
1897 prot |= VM_PROT_WRITE;
1898 if (flags & PF_R)
1899 prot |= VM_PROT_READ;
1900 return (prot);
1901 }
1902
1903 static Elf_Word
__elfN(untrans_prot)1904 __elfN(untrans_prot)(vm_prot_t prot)
1905 {
1906 Elf_Word flags;
1907
1908 flags = 0;
1909 if (prot & VM_PROT_EXECUTE)
1910 flags |= PF_X;
1911 if (prot & VM_PROT_READ)
1912 flags |= PF_R;
1913 if (prot & VM_PROT_WRITE)
1914 flags |= PF_W;
1915 return (flags);
1916 }
1917
1918 static u_long
pie_base_hint(struct proc * p)1919 pie_base_hint(struct proc *p)
1920 {
1921 u_long base;
1922
1923 if (elf_pie_base_mmap)
1924 base = vm_map_hint(p, 0, VM_PROT_READ | VM_PROT_EXECUTE);
1925 else
1926 base = ET_DYN_LOAD_ADDR;
1927 return base;
1928 }
1929