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kernel - Remove unused process_exit and process_exec eventhandlers
[dragonfly.git] / sys / kern / imgact_elf.c
blob67b1153ebc92d43e700bce147d067c789b88b8ed
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) ((va) & ~(ps - 1))
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 static const char FREEBSD_ABI_VENDOR[] = "FreeBSD";
129
130 Elf_Brandnote __elfN(dragonfly_brandnote) = {
131 .hdr.n_namesz = sizeof(DRAGONFLY_ABI_VENDOR),
132 .hdr.n_descsz = sizeof(int32_t),
133 .hdr.n_type = 1,
134 .vendor = DRAGONFLY_ABI_VENDOR,
135 .flags = BN_TRANSLATE_OSREL,
136 .trans_osrel = __elfN(bsd_trans_osrel),
137 };
138
139 Elf_Brandnote __elfN(freebsd_brandnote) = {
140 .hdr.n_namesz = sizeof(FREEBSD_ABI_VENDOR),
141 .hdr.n_descsz = sizeof(int32_t),
142 .hdr.n_type = 1,
143 .vendor = FREEBSD_ABI_VENDOR,
144 .flags = BN_TRANSLATE_OSREL,
145 .trans_osrel = __elfN(bsd_trans_osrel),
146 };
147
148 int
149 __elfN(insert_brand_entry)(Elf_Brandinfo *entry)
150 {
151 int i;
152
153 for (i = 0; i < MAX_BRANDS; i++) {
154 if (elf_brand_list[i] == NULL) {
155 elf_brand_list[i] = entry;
156 break;
157 }
158 }
159 if (i == MAX_BRANDS) {
160 uprintf("WARNING: %s: could not insert brandinfo entry: %p\n",
161 __func__, entry);
162 return (-1);
163 }
164 return (0);
165 }
166
167 int
168 __elfN(remove_brand_entry)(Elf_Brandinfo *entry)
169 {
170 int i;
171
172 for (i = 0; i < MAX_BRANDS; i++) {
173 if (elf_brand_list[i] == entry) {
174 elf_brand_list[i] = NULL;
175 break;
176 }
177 }
178 if (i == MAX_BRANDS)
179 return (-1);
180 return (0);
181 }
182
183 /*
184 * Check if an elf brand is being used anywhere in the system.
185 *
186 * Used by the linux emulation module unloader. This isn't safe from
187 * races.
188 */
189 struct elf_brand_inuse_info {
190 int rval;
191 Elf_Brandinfo *entry;
192 };
193
194 static int elf_brand_inuse_callback(struct proc *p, void *data);
195
196 int
197 __elfN(brand_inuse)(Elf_Brandinfo *entry)
198 {
199 struct elf_brand_inuse_info info;
200
201 info.rval = FALSE;
202 info.entry = entry;
203 allproc_scan(elf_brand_inuse_callback, &info);
204 return (info.rval);
205 }
206
207 static
208 int
209 elf_brand_inuse_callback(struct proc *p, void *data)
210 {
211 struct elf_brand_inuse_info *info = data;
212
213 if (p->p_sysent == info->entry->sysvec) {
214 info->rval = TRUE;
215 return (-1);
216 }
217 return (0);
218 }
219
220 static int
221 __elfN(check_header)(const Elf_Ehdr *hdr)
222 {
223 Elf_Brandinfo *bi;
224 int i;
225
226 if (!IS_ELF(*hdr) ||
227 hdr->e_ident[EI_CLASS] != ELF_TARG_CLASS ||
228 hdr->e_ident[EI_DATA] != ELF_TARG_DATA ||
229 hdr->e_ident[EI_VERSION] != EV_CURRENT ||
230 hdr->e_phentsize != sizeof(Elf_Phdr) ||
231 hdr->e_ehsize != sizeof(Elf_Ehdr) ||
232 hdr->e_version != ELF_TARG_VER)
233 return (ENOEXEC);
234
235 /*
236 * Make sure we have at least one brand for this machine.
237 */
238
239 for (i = 0; i < MAX_BRANDS; i++) {
240 bi = elf_brand_list[i];
241 if (bi != NULL && bi->machine == hdr->e_machine)
242 break;
243 }
244 if (i == MAX_BRANDS)
245 return (ENOEXEC);
246
247 return (0);
248 }
249
250 static int
251 __elfN(load_section)(struct proc *p, struct vmspace *vmspace, struct vnode *vp,
252 vm_offset_t offset, caddr_t vmaddr, size_t memsz,
253 size_t filsz, vm_prot_t prot)
254 {
255 size_t map_len;
256 vm_offset_t map_addr;
257 int error, rv, cow;
258 int count;
259 int shared;
260 size_t copy_len;
261 vm_object_t object;
262 vm_offset_t file_addr;
263
264 object = vp->v_object;
265 error = 0;
266
267 /*
268 * In most cases we will be able to use a shared lock on the
269 * object we are inserting into the map. The lock will be
270 * upgraded in situations where new VM pages must be allocated.
271 */
272 vm_object_hold_shared(object);
273 shared = 1;
274
275 /*
276 * It's necessary to fail if the filsz + offset taken from the
277 * header is greater than the actual file pager object's size.
278 * If we were to allow this, then the vm_map_find() below would
279 * walk right off the end of the file object and into the ether.
280 *
281 * While I'm here, might as well check for something else that
282 * is invalid: filsz cannot be greater than memsz.
283 */
284 if ((off_t)filsz + offset > vp->v_filesize || filsz > memsz) {
285 uprintf("elf_load_section: truncated ELF file\n");
286 vm_object_drop(object);
287 return (ENOEXEC);
288 }
289
290 map_addr = trunc_page((vm_offset_t)vmaddr);
291 file_addr = trunc_page(offset);
292
293 /*
294 * We have two choices. We can either clear the data in the last page
295 * of an oversized mapping, or we can start the anon mapping a page
296 * early and copy the initialized data into that first page. We
297 * choose the second..
298 */
299 if (memsz > filsz)
300 map_len = trunc_page(offset+filsz) - file_addr;
301 else
302 map_len = round_page(offset+filsz) - file_addr;
303
304 if (map_len != 0) {
305 vm_object_reference_locked(object);
306
307 /* cow flags: don't dump readonly sections in core */
308 cow = MAP_COPY_ON_WRITE | MAP_PREFAULT;
309 if ((prot & VM_PROT_WRITE) == 0)
310 cow |= MAP_DISABLE_COREDUMP;
311 if (shared == 0)
312 cow |= MAP_PREFAULT_RELOCK;
313
314 count = vm_map_entry_reserve(MAP_RESERVE_COUNT);
315 vm_map_lock(&vmspace->vm_map);
316 rv = vm_map_insert(&vmspace->vm_map, &count,
317 object, NULL,
318 file_addr, /* file offset */
319 map_addr, /* virtual start */
320 map_addr + map_len,/* virtual end */
321 VM_MAPTYPE_NORMAL,
322 prot, VM_PROT_ALL,
323 cow);
324 vm_map_unlock(&vmspace->vm_map);
325 vm_map_entry_release(count);
326
327 /*
328 * NOTE: Object must have a hold ref when calling
329 * vm_object_deallocate().
330 */
331 if (rv != KERN_SUCCESS) {
332 vm_object_drop(object);
333 vm_object_deallocate(object);
334 return (EINVAL);
335 }
336
337 /* we can stop now if we've covered it all */
338 if (memsz == filsz) {
339 vm_object_drop(object);
340 return (0);
341 }
342 }
343
344 /*
345 * We have to get the remaining bit of the file into the first part
346 * of the oversized map segment. This is normally because the .data
347 * segment in the file is extended to provide bss. It's a neat idea
348 * to try and save a page, but it's a pain in the behind to implement.
349 */
350 copy_len = (offset + filsz) - trunc_page(offset + filsz);
351 map_addr = trunc_page((vm_offset_t)vmaddr + filsz);
352 map_len = round_page((vm_offset_t)vmaddr + memsz) - map_addr;
353
354 /* This had damn well better be true! */
355 if (map_len != 0) {
356 count = vm_map_entry_reserve(MAP_RESERVE_COUNT);
357 vm_map_lock(&vmspace->vm_map);
358 rv = vm_map_insert(&vmspace->vm_map, &count,
359 NULL, NULL,
360 0,
361 map_addr,
362 map_addr + map_len,
363 VM_MAPTYPE_NORMAL,
364 VM_PROT_ALL, VM_PROT_ALL,
365 0);
366 vm_map_unlock(&vmspace->vm_map);
367 vm_map_entry_release(count);
368 if (rv != KERN_SUCCESS) {
369 vm_object_drop(object);
370 return (EINVAL);
371 }
372 }
373
374 if (copy_len != 0) {
375 struct lwbuf *lwb;
376 struct lwbuf lwb_cache;
377 vm_page_t m;
378
379 m = vm_fault_object_page(object, trunc_page(offset + filsz),
380 VM_PROT_READ, 0, &shared, &error);
381 vm_object_drop(object);
382 if (m) {
383 lwb = lwbuf_alloc(m, &lwb_cache);
384 error = copyout((caddr_t)lwbuf_kva(lwb),
385 (caddr_t)map_addr, copy_len);
386 lwbuf_free(lwb);
387 vm_page_unhold(m);
388 }
389 } else {
390 vm_object_drop(object);
391 }
392
393 /*
394 * set it to the specified protection
395 */
396 if (error == 0) {
397 vm_map_protect(&vmspace->vm_map,
398 map_addr, map_addr + map_len,
399 prot, FALSE);
400 }
401 return (error);
402 }
403
404 /*
405 * Load the file "file" into memory. It may be either a shared object
406 * or an executable.
407 *
408 * The "addr" reference parameter is in/out. On entry, it specifies
409 * the address where a shared object should be loaded. If the file is
410 * an executable, this value is ignored. On exit, "addr" specifies
411 * where the file was actually loaded.
412 *
413 * The "entry" reference parameter is out only. On exit, it specifies
414 * the entry point for the loaded file.
415 */
416 static int
417 __elfN(load_file)(struct proc *p, const char *file, u_long *addr, u_long *entry)
418 {
419 struct {
420 struct nlookupdata nd;
421 struct vattr attr;
422 struct image_params image_params;
423 } *tempdata;
424 const Elf_Ehdr *hdr = NULL;
425 const Elf_Phdr *phdr = NULL;
426 struct nlookupdata *nd;
427 struct vmspace *vmspace = p->p_vmspace;
428 struct vattr *attr;
429 struct image_params *imgp;
430 struct mount *topmnt;
431 vm_prot_t prot;
432 u_long rbase;
433 u_long base_addr = 0;
434 int error, i, numsegs;
435
436 tempdata = kmalloc(sizeof(*tempdata), M_TEMP, M_WAITOK);
437 nd = &tempdata->nd;
438 attr = &tempdata->attr;
439 imgp = &tempdata->image_params;
440
441 /*
442 * Initialize part of the common data
443 */
444 imgp->proc = p;
445 imgp->attr = attr;
446 imgp->firstpage = NULL;
447 imgp->image_header = NULL;
448 imgp->vp = NULL;
449
450 error = nlookup_init(nd, file, UIO_SYSSPACE, NLC_FOLLOW);
451 if (error == 0)
452 error = nlookup(nd);
453 if (error == 0)
454 error = cache_vget(&nd->nl_nch, nd->nl_cred,
455 LK_SHARED, &imgp->vp);
456 topmnt = nd->nl_nch.mount;
457 nlookup_done(nd);
458 if (error)
459 goto fail;
460
461 /*
462 * Check permissions, modes, uid, etc on the file, and "open" it.
463 */
464 error = exec_check_permissions(imgp, topmnt);
465 if (error) {
466 vn_unlock(imgp->vp);
467 goto fail;
468 }
469
470 error = exec_map_first_page(imgp);
471 /*
472 * Also make certain that the interpreter stays the same, so set
473 * its VTEXT flag, too.
474 */
475 if (error == 0)
476 vsetflags(imgp->vp, VTEXT);
477 vn_unlock(imgp->vp);
478 if (error)
479 goto fail;
480
481 hdr = (const Elf_Ehdr *)imgp->image_header;
482 if ((error = __elfN(check_header)(hdr)) != 0)
483 goto fail;
484 if (hdr->e_type == ET_DYN)
485 rbase = *addr;
486 else if (hdr->e_type == ET_EXEC)
487 rbase = 0;
488 else {
489 error = ENOEXEC;
490 goto fail;
491 }
492
493 /* Only support headers that fit within first page for now */
494 /* (multiplication of two Elf_Half fields will not overflow) */
495 if ((hdr->e_phoff > PAGE_SIZE) ||
496 (hdr->e_phentsize * hdr->e_phnum) > PAGE_SIZE - hdr->e_phoff) {
497 error = ENOEXEC;
498 goto fail;
499 }
500
501 phdr = (const Elf_Phdr *)(imgp->image_header + hdr->e_phoff);
502 if (!aligned(phdr, Elf_Addr)) {
503 error = ENOEXEC;
504 goto fail;
505 }
506
507 for (i = 0, numsegs = 0; i < hdr->e_phnum; i++) {
508 if (phdr[i].p_type == PT_LOAD && phdr[i].p_memsz != 0) {
509 /* Loadable segment */
510 prot = __elfN(trans_prot)(phdr[i].p_flags);
511 error = __elfN(load_section)(
512 p, vmspace, imgp->vp,
513 phdr[i].p_offset,
514 (caddr_t)phdr[i].p_vaddr +
515 rbase,
516 phdr[i].p_memsz,
517 phdr[i].p_filesz, prot);
518 if (error != 0)
519 goto fail;
520 /*
521 * Establish the base address if this is the
522 * first segment.
523 */
524 if (numsegs == 0)
525 base_addr = trunc_page(phdr[i].p_vaddr + rbase);
526 numsegs++;
527 }
528 }
529 *addr = base_addr;
530 *entry = (unsigned long)hdr->e_entry + rbase;
531
532 fail:
533 if (imgp->firstpage)
534 exec_unmap_first_page(imgp);
535 if (imgp->vp) {
536 vrele(imgp->vp);
537 imgp->vp = NULL;
538 }
539 kfree(tempdata, M_TEMP);
540
541 return (error);
542 }
543
544 static Elf_Brandinfo *
545 __elfN(get_brandinfo)(struct image_params *imgp, const char *interp,
546 int32_t *osrel)
547 {
548 const Elf_Ehdr *hdr = (const Elf_Ehdr *)imgp->image_header;
549 Elf_Brandinfo *bi;
550 boolean_t ret;
551 int i;
552
553 /* We support four types of branding -- (1) the ELF EI_OSABI field
554 * that SCO added to the ELF spec, (2) FreeBSD 3.x's traditional string
555 * branding within the ELF header, (3) path of the `interp_path' field,
556 * and (4) the ".note.ABI-tag" ELF section.
557 */
558
559 /* Look for an ".note.ABI-tag" ELF section */
560 for (i = 0; i < MAX_BRANDS; i++) {
561 bi = elf_brand_list[i];
562
563 if (bi == NULL)
564 continue;
565 if (hdr->e_machine == bi->machine && (bi->flags &
566 (BI_BRAND_NOTE|BI_BRAND_NOTE_MANDATORY)) != 0) {
567 ret = __elfN(check_note)(imgp, bi->brand_note, osrel);
568 if (ret)
569 return (bi);
570 }
571 }
572
573 /* If the executable has a brand, search for it in the brand list. */
574 for (i = 0; i < MAX_BRANDS; i++) {
575 bi = elf_brand_list[i];
576
577 if (bi == NULL || bi->flags & BI_BRAND_NOTE_MANDATORY)
578 continue;
579 if (hdr->e_machine == bi->machine &&
580 (hdr->e_ident[EI_OSABI] == bi->brand ||
581 strncmp((const char *)&hdr->e_ident[OLD_EI_BRAND],
582 bi->compat_3_brand, strlen(bi->compat_3_brand)) == 0))
583 return (bi);
584 }
585
586 /* Lacking a known brand, search for a recognized interpreter. */
587 if (interp != NULL) {
588 for (i = 0; i < MAX_BRANDS; i++) {
589 bi = elf_brand_list[i];
590
591 if (bi == NULL || bi->flags & BI_BRAND_NOTE_MANDATORY)
592 continue;
593 if (hdr->e_machine == bi->machine &&
594 strcmp(interp, bi->interp_path) == 0)
595 return (bi);
596 }
597 }
598
599 /* Lacking a recognized interpreter, try the default brand */
600 for (i = 0; i < MAX_BRANDS; i++) {
601 bi = elf_brand_list[i];
602
603 if (bi == NULL || bi->flags & BI_BRAND_NOTE_MANDATORY)
604 continue;
605 if (hdr->e_machine == bi->machine &&
606 __elfN(fallback_brand) == bi->brand)
607 return (bi);
608 }
609 return (NULL);
610 }
611
612 static int
613 __CONCAT(exec_,__elfN(imgact))(struct image_params *imgp)
614 {
615 const Elf_Ehdr *hdr = (const Elf_Ehdr *) imgp->image_header;
616 const Elf_Phdr *phdr;
617 Elf_Auxargs *elf_auxargs;
618 struct vmspace *vmspace;
619 vm_prot_t prot;
620 u_long text_size = 0, data_size = 0, total_size = 0;
621 u_long text_addr = 0, data_addr = 0;
622 u_long seg_size, seg_addr;
623 u_long addr, baddr, et_dyn_addr = 0, entry = 0, proghdr = 0;
624 int32_t osrel = 0;
625 int error = 0, i, n;
626 boolean_t failure;
627 char *interp = NULL;
628 const char *newinterp = NULL;
629 Elf_Brandinfo *brand_info;
630 char *path;
631
632 /*
633 * Do we have a valid ELF header ?
634 *
635 * Only allow ET_EXEC & ET_DYN here, reject ET_DYN later if a particular
636 * brand doesn't support it. Both DragonFly platforms do by default.
637 */
638 if (__elfN(check_header)(hdr) != 0 ||
639 (hdr->e_type != ET_EXEC && hdr->e_type != ET_DYN))
640 return (-1);
641
642 /*
643 * From here on down, we return an errno, not -1, as we've
644 * detected an ELF file.
645 */
646
647 if ((hdr->e_phoff > PAGE_SIZE) ||
648 (hdr->e_phoff + hdr->e_phentsize * hdr->e_phnum) > PAGE_SIZE) {
649 /* Only support headers in first page for now */
650 return (ENOEXEC);
651 }
652 phdr = (const Elf_Phdr *)(imgp->image_header + hdr->e_phoff);
653 if (!aligned(phdr, Elf_Addr))
654 return (ENOEXEC);
655 n = 0;
656 baddr = 0;
657 for (i = 0; i < hdr->e_phnum; i++) {
658 if (phdr[i].p_type == PT_LOAD) {
659 if (n == 0)
660 baddr = phdr[i].p_vaddr;
661 n++;
662 continue;
663 }
664 if (phdr[i].p_type == PT_INTERP) {
665 /*
666 * If interp is already defined there are more than
667 * one PT_INTERP program headers present. Take only
668 * the first one and ignore the rest.
669 */
670 if (interp != NULL)
671 continue;
672
673 if (phdr[i].p_filesz == 0 ||
674 phdr[i].p_filesz > PAGE_SIZE ||
675 phdr[i].p_filesz > MAXPATHLEN)
676 return (ENOEXEC);
677
678 interp = kmalloc(phdr[i].p_filesz, M_TEMP, M_WAITOK);
679 failure = extract_interpreter(imgp, &phdr[i], interp);
680 if (failure) {
681 kfree(interp, M_TEMP);
682 return (ENOEXEC);
683 }
684 continue;
685 }
686 }
687
688 brand_info = __elfN(get_brandinfo)(imgp, interp, &osrel);
689 if (brand_info == NULL) {
690 uprintf("ELF binary type \"%u\" not known.\n",
691 hdr->e_ident[EI_OSABI]);
692 if (interp != NULL)
693 kfree(interp, M_TEMP);
694 return (ENOEXEC);
695 }
696 if (hdr->e_type == ET_DYN) {
697 if ((brand_info->flags & BI_CAN_EXEC_DYN) == 0) {
698 if (interp != NULL)
699 kfree(interp, M_TEMP);
700 return (ENOEXEC);
701 }
702 /*
703 * If p_vaddr field of PT_LOAD program header is zero and type of an
704 * executale is ET_DYN, then it must be a position independent
705 * executable (PIE). In this case the system needs to pick a base
706 * address for us. Set et_dyn_addr to non-zero and choose the actual
707 * address when we are ready.
708 */
709 if (baddr == 0)
710 et_dyn_addr = 1;
711 }
712
713 if (interp != NULL && brand_info->interp_newpath != NULL)
714 newinterp = brand_info->interp_newpath;
715
716 exec_new_vmspace(imgp, NULL);
717
718 /*
719 * Yeah, I'm paranoid. There is every reason in the world to get
720 * VTEXT now since from here on out, there are places we can have
721 * a context switch. Better safe than sorry; I really don't want
722 * the file to change while it's being loaded.
723 */
724 vsetflags(imgp->vp, VTEXT);
725
726 vmspace = imgp->proc->p_vmspace;
727 /* Choose the base address for dynamic executables if we need to. */
728 if (et_dyn_addr)
729 et_dyn_addr = pie_base_hint(imgp->proc);
730
731 for (i = 0; i < hdr->e_phnum; i++) {
732 switch (phdr[i].p_type) {
733 case PT_LOAD: /* Loadable segment */
734 if (phdr[i].p_memsz == 0)
735 break;
736 prot = __elfN(trans_prot)(phdr[i].p_flags);
737
738 if ((error = __elfN(load_section)(
739 imgp->proc,
740 vmspace,
741 imgp->vp,
742 phdr[i].p_offset,
743 (caddr_t)phdr[i].p_vaddr + et_dyn_addr,
744 phdr[i].p_memsz,
745 phdr[i].p_filesz,
746 prot)) != 0) {
747 if (interp != NULL)
748 kfree (interp, M_TEMP);
749 return (error);
750 }
751
752 /*
753 * If this segment contains the program headers,
754 * remember their virtual address for the AT_PHDR
755 * aux entry. Static binaries don't usually include
756 * a PT_PHDR entry.
757 */
758 if (phdr[i].p_offset == 0 &&
759 hdr->e_phoff + hdr->e_phnum * hdr->e_phentsize
760 <= phdr[i].p_filesz)
761 proghdr = phdr[i].p_vaddr + hdr->e_phoff +
762 et_dyn_addr;
763
764 seg_addr = trunc_page(phdr[i].p_vaddr + et_dyn_addr);
765 seg_size = round_page(phdr[i].p_memsz +
766 phdr[i].p_vaddr + et_dyn_addr - seg_addr);
767
768 /*
769 * Is this .text or .data? We can't use
770 * VM_PROT_WRITE or VM_PROT_EXEC, it breaks the
771 * alpha terribly and possibly does other bad
772 * things so we stick to the old way of figuring
773 * it out: If the segment contains the program
774 * entry point, it's a text segment, otherwise it
775 * is a data segment.
776 *
777 * Note that obreak() assumes that data_addr +
778 * data_size == end of data load area, and the ELF
779 * file format expects segments to be sorted by
780 * address. If multiple data segments exist, the
781 * last one will be used.
782 */
783 if (hdr->e_entry >= phdr[i].p_vaddr &&
784 hdr->e_entry < (phdr[i].p_vaddr +
785 phdr[i].p_memsz)) {
786 text_size = seg_size;
787 text_addr = seg_addr;
788 entry = (u_long)hdr->e_entry + et_dyn_addr;
789 } else {
790 data_size = seg_size;
791 data_addr = seg_addr;
792 }
793 total_size += seg_size;
794
795 /*
796 * Check limits. It should be safe to check the
797 * limits after loading the segment since we do
798 * not actually fault in all the segment's pages.
799 */
800 if (data_size >
801 imgp->proc->p_rlimit[RLIMIT_DATA].rlim_cur ||
802 text_size > maxtsiz ||
803 total_size >
804 imgp->proc->p_rlimit[RLIMIT_VMEM].rlim_cur) {
805 if (interp != NULL)
806 kfree(interp, M_TEMP);
807 error = ENOMEM;
808 return (error);
809 }
810 break;
811 case PT_PHDR: /* Program header table info */
812 proghdr = phdr[i].p_vaddr + et_dyn_addr;
813 break;
814 default:
815 break;
816 }
817 }
818
819 vmspace->vm_tsize = text_size >> PAGE_SHIFT;
820 vmspace->vm_taddr = (caddr_t)(uintptr_t)text_addr;
821 vmspace->vm_dsize = data_size >> PAGE_SHIFT;
822 vmspace->vm_daddr = (caddr_t)(uintptr_t)data_addr;
823
824 addr = ELF_RTLD_ADDR(vmspace);
825
826 imgp->entry_addr = entry;
827
828 imgp->proc->p_sysent = brand_info->sysvec;
829
830 if (interp != NULL) {
831 int have_interp = FALSE;
832 if (brand_info->emul_path != NULL &&
833 brand_info->emul_path[0] != '\0') {
834 path = kmalloc(MAXPATHLEN, M_TEMP, M_WAITOK);
835 ksnprintf(path, MAXPATHLEN, "%s%s",
836 brand_info->emul_path, interp);
837 error = __elfN(load_file)(imgp->proc, path, &addr,
838 &imgp->entry_addr);
839 kfree(path, M_TEMP);
840 if (error == 0)
841 have_interp = TRUE;
842 }
843 if (!have_interp && newinterp != NULL) {
844 error = __elfN(load_file)(imgp->proc, newinterp,
845 &addr, &imgp->entry_addr);
846 if (error == 0)
847 have_interp = TRUE;
848 }
849 if (!have_interp) {
850 error = __elfN(load_file)(imgp->proc, interp, &addr,
851 &imgp->entry_addr);
852 }
853 if (error != 0) {
854 uprintf("ELF interpreter %s not found\n", interp);
855 kfree(interp, M_TEMP);
856 return (error);
857 }
858 kfree(interp, M_TEMP);
859 } else
860 addr = et_dyn_addr;
861
862 /*
863 * Construct auxargs table (used by the fixup routine)
864 */
865 elf_auxargs = kmalloc(sizeof(Elf_Auxargs), M_TEMP, M_WAITOK);
866 elf_auxargs->execfd = -1;
867 elf_auxargs->phdr = proghdr;
868 elf_auxargs->phent = hdr->e_phentsize;
869 elf_auxargs->phnum = hdr->e_phnum;
870 elf_auxargs->pagesz = PAGE_SIZE;
871 elf_auxargs->base = addr;
872 elf_auxargs->flags = 0;
873 elf_auxargs->entry = entry;
874
875 imgp->auxargs = elf_auxargs;
876 imgp->interpreted = 0;
877 imgp->proc->p_osrel = osrel;
878
879 return (error);
880 }
881
882 int
883 __elfN(dragonfly_fixup)(register_t **stack_base, struct image_params *imgp)
884 {
885 Elf_Auxargs *args = (Elf_Auxargs *)imgp->auxargs;
886 Elf_Addr *base;
887 Elf_Addr *pos;
888
889 base = (Elf_Addr *)*stack_base;
890 pos = base + (imgp->args->argc + imgp->args->envc + 2);
891
892 if (args->execfd != -1)
893 AUXARGS_ENTRY(pos, AT_EXECFD, args->execfd);
894 AUXARGS_ENTRY(pos, AT_PHDR, args->phdr);
895 AUXARGS_ENTRY(pos, AT_PHENT, args->phent);
896 AUXARGS_ENTRY(pos, AT_PHNUM, args->phnum);
897 AUXARGS_ENTRY(pos, AT_PAGESZ, args->pagesz);
898 AUXARGS_ENTRY(pos, AT_FLAGS, args->flags);
899 AUXARGS_ENTRY(pos, AT_ENTRY, args->entry);
900 AUXARGS_ENTRY(pos, AT_BASE, args->base);
901 if (imgp->execpathp != 0)
902 AUXARGS_ENTRY(pos, AT_EXECPATH, imgp->execpathp);
903 AUXARGS_ENTRY(pos, AT_OSRELDATE, osreldate);
904 AUXARGS_ENTRY(pos, AT_NULL, 0);
905
906 kfree(imgp->auxargs, M_TEMP);
907 imgp->auxargs = NULL;
908
909 base--;
910 suword(base, (long)imgp->args->argc);
911 *stack_base = (register_t *)base;
912 return (0);
913 }
914
915 /*
916 * Code for generating ELF core dumps.
917 */
918
919 typedef int (*segment_callback)(vm_map_entry_t, void *);
920
921 /* Closure for cb_put_phdr(). */
922 struct phdr_closure {
923 Elf_Phdr *phdr; /* Program header to fill in (incremented) */
924 Elf_Phdr *phdr_max; /* Pointer bound for error check */
925 Elf_Off offset; /* Offset of segment in core file */
926 };
927
928 /* Closure for cb_size_segment(). */
929 struct sseg_closure {
930 int count; /* Count of writable segments. */
931 size_t vsize; /* Total size of all writable segments. */
932 };
933
934 /* Closure for cb_put_fp(). */
935 struct fp_closure {
936 struct vn_hdr *vnh;
937 struct vn_hdr *vnh_max;
938 int count;
939 struct stat *sb;
940 };
941
942 typedef struct elf_buf {
943 char *buf;
944 size_t off;
945 size_t off_max;
946 } *elf_buf_t;
947
948 static void *target_reserve(elf_buf_t target, size_t bytes, int *error);
949
950 static int cb_put_phdr (vm_map_entry_t, void *);
951 static int cb_size_segment (vm_map_entry_t, void *);
952 static int cb_fpcount_segment(vm_map_entry_t, void *);
953 static int cb_put_fp(vm_map_entry_t, void *);
954
955
956 static int each_segment (struct proc *, segment_callback, void *, int);
957 static int __elfN(corehdr)(struct lwp *, int, struct file *, struct ucred *,
958 int, elf_buf_t);
959 enum putmode { WRITE, DRYRUN };
960 static int __elfN(puthdr)(struct lwp *, elf_buf_t, int sig, enum putmode,
961 int, struct file *);
962 static int elf_putallnotes(struct lwp *, elf_buf_t, int, enum putmode);
963 static int __elfN(putnote)(elf_buf_t, const char *, int, const void *, size_t);
964
965 static int elf_putsigs(struct lwp *, elf_buf_t);
966 static int elf_puttextvp(struct proc *, elf_buf_t);
967 static int elf_putfiles(struct proc *, elf_buf_t, struct file *);
968
969 int
970 __elfN(coredump)(struct lwp *lp, int sig, struct vnode *vp, off_t limit)
971 {
972 struct file *fp;
973 int error;
974
975 if ((error = falloc(NULL, &fp, NULL)) != 0)
976 return (error);
977 fsetcred(fp, lp->lwp_proc->p_ucred);
978
979 /*
980 * XXX fixme.
981 */
982 fp->f_type = DTYPE_VNODE;
983 fp->f_flag = O_CREAT|O_WRONLY|O_NOFOLLOW;
984 fp->f_ops = &vnode_fileops;
985 fp->f_data = vp;
986
987 error = generic_elf_coredump(lp, sig, fp, limit);
988
989 fp->f_type = 0;
990 fp->f_flag = 0;
991 fp->f_ops = &badfileops;
992 fp->f_data = NULL;
993 fdrop(fp);
994 return (error);
995 }
996
997 int
998 generic_elf_coredump(struct lwp *lp, int sig, struct file *fp, off_t limit)
999 {
1000 struct proc *p = lp->lwp_proc;
1001 struct ucred *cred = p->p_ucred;
1002 int error = 0;
1003 struct sseg_closure seginfo;
1004 struct elf_buf target;
1005
1006 if (!fp)
1007 kprintf("can't dump core - null fp\n");
1008
1009 /*
1010 * Size the program segments
1011 */
1012 seginfo.count = 0;
1013 seginfo.vsize = 0;
1014 each_segment(p, cb_size_segment, &seginfo, 1);
1015
1016 /*
1017 * Calculate the size of the core file header area by making
1018 * a dry run of generating it. Nothing is written, but the
1019 * size is calculated.
1020 */
1021 bzero(&target, sizeof(target));
1022 __elfN(puthdr)(lp, &target, sig, DRYRUN, seginfo.count, fp);
1023
1024 if (target.off + seginfo.vsize >= limit)
1025 return (EFAULT);
1026
1027 /*
1028 * Allocate memory for building the header, fill it up,
1029 * and write it out.
1030 */
1031 target.off_max = target.off;
1032 target.off = 0;
1033 target.buf = kmalloc(target.off_max, M_TEMP, M_WAITOK|M_ZERO);
1034
1035 error = __elfN(corehdr)(lp, sig, fp, cred, seginfo.count, &target);
1036
1037 /* Write the contents of all of the writable segments. */
1038 if (error == 0) {
1039 Elf_Phdr *php;
1040 int i;
1041 ssize_t nbytes;
1042
1043 php = (Elf_Phdr *)(target.buf + sizeof(Elf_Ehdr)) + 1;
1044 for (i = 0; i < seginfo.count; i++) {
1045 error = fp_write(fp, (caddr_t)php->p_vaddr,
1046 php->p_filesz, &nbytes, UIO_USERSPACE);
1047 if (error != 0)
1048 break;
1049 php++;
1050 }
1051 }
1052 kfree(target.buf, M_TEMP);
1053
1054 return (error);
1055 }
1056
1057 /*
1058 * A callback for each_segment() to write out the segment's
1059 * program header entry.
1060 */
1061 static int
1062 cb_put_phdr(vm_map_entry_t entry, void *closure)
1063 {
1064 struct phdr_closure *phc = closure;
1065 Elf_Phdr *phdr = phc->phdr;
1066
1067 if (phc->phdr == phc->phdr_max)
1068 return (EINVAL);
1069
1070 phc->offset = round_page(phc->offset);
1071
1072 phdr->p_type = PT_LOAD;
1073 phdr->p_offset = phc->offset;
1074 phdr->p_vaddr = entry->start;
1075 phdr->p_paddr = 0;
1076 phdr->p_filesz = phdr->p_memsz = entry->end - entry->start;
1077 phdr->p_align = PAGE_SIZE;
1078 phdr->p_flags = __elfN(untrans_prot)(entry->protection);
1079
1080 phc->offset += phdr->p_filesz;
1081 ++phc->phdr;
1082 return (0);
1083 }
1084
1085 /*
1086 * A callback for each_writable_segment() to gather information about
1087 * the number of segments and their total size.
1088 */
1089 static int
1090 cb_size_segment(vm_map_entry_t entry, void *closure)
1091 {
1092 struct sseg_closure *ssc = closure;
1093
1094 ++ssc->count;
1095 ssc->vsize += entry->end - entry->start;
1096 return (0);
1097 }
1098
1099 /*
1100 * A callback for each_segment() to gather information about
1101 * the number of text segments.
1102 */
1103 static int
1104 cb_fpcount_segment(vm_map_entry_t entry, void *closure)
1105 {
1106 int *count = closure;
1107 struct vnode *vp;
1108
1109 if (entry->object.vm_object->type == OBJT_VNODE) {
1110 vp = (struct vnode *)entry->object.vm_object->handle;
1111 if ((vp->v_flag & VCKPT) && curproc->p_textvp == vp)
1112 return (0);
1113 ++*count;
1114 }
1115 return (0);
1116 }
1117
1118 static int
1119 cb_put_fp(vm_map_entry_t entry, void *closure)
1120 {
1121 struct fp_closure *fpc = closure;
1122 struct vn_hdr *vnh = fpc->vnh;
1123 Elf_Phdr *phdr = &vnh->vnh_phdr;
1124 struct vnode *vp;
1125 int error;
1126
1127 /*
1128 * If an entry represents a vnode then write out a file handle.
1129 *
1130 * If we are checkpointing a checkpoint-restored program we do
1131 * NOT record the filehandle for the old checkpoint vnode (which
1132 * is mapped all over the place). Instead we rely on the fact
1133 * that a checkpoint-restored program does not mmap() the checkpt
1134 * vnode NOCORE, so its contents will be written out to the
1135 * new checkpoint file. This is necessary because the 'old'
1136 * checkpoint file is typically destroyed when a new one is created
1137 * and thus cannot be used to restore the new checkpoint.
1138 *
1139 * Theoretically we could create a chain of checkpoint files and
1140 * operate the checkpointing operation kinda like an incremental
1141 * checkpoint, but a checkpoint restore would then likely wind up
1142 * referencing many prior checkpoint files and that is a bit over
1143 * the top for the purpose of the checkpoint API.
1144 */
1145 if (entry->object.vm_object->type == OBJT_VNODE) {
1146 vp = (struct vnode *)entry->object.vm_object->handle;
1147 if ((vp->v_flag & VCKPT) && curproc->p_textvp == vp)
1148 return (0);
1149 if (vnh == fpc->vnh_max)
1150 return (EINVAL);
1151
1152 if (vp->v_mount)
1153 vnh->vnh_fh.fh_fsid = vp->v_mount->mnt_stat.f_fsid;
1154 error = VFS_VPTOFH(vp, &vnh->vnh_fh.fh_fid);
1155 if (error) {
1156 char *freepath, *fullpath;
1157
1158 /*
1159 * This is actually a relatively common occurance,
1160 * so don't spew on the console by default.
1161 */
1162 if (vn_fullpath(curproc, vp, &fullpath, &freepath, 0)) {
1163 if (bootverbose)
1164 kprintf("Warning: coredump, error %d: cannot store file handle for vnode %p\n", error, vp);
1165 } else {
1166 if (bootverbose)
1167 kprintf("Warning: coredump, error %d: cannot store file handle for %s\n", error, fullpath);
1168 kfree(freepath, M_TEMP);
1169 }
1170 error = 0;
1171 }
1172
1173 phdr->p_type = PT_LOAD;
1174 phdr->p_offset = 0; /* not written to core */
1175 phdr->p_vaddr = entry->start;
1176 phdr->p_paddr = 0;
1177 phdr->p_filesz = phdr->p_memsz = entry->end - entry->start;
1178 phdr->p_align = PAGE_SIZE;
1179 phdr->p_flags = 0;
1180 if (entry->protection & VM_PROT_READ)
1181 phdr->p_flags |= PF_R;
1182 if (entry->protection & VM_PROT_WRITE)
1183 phdr->p_flags |= PF_W;
1184 if (entry->protection & VM_PROT_EXECUTE)
1185 phdr->p_flags |= PF_X;
1186 ++fpc->vnh;
1187 ++fpc->count;
1188 }
1189 return (0);
1190 }
1191
1192 /*
1193 * For each writable segment in the process's memory map, call the given
1194 * function with a pointer to the map entry and some arbitrary
1195 * caller-supplied data.
1196 */
1197 static int
1198 each_segment(struct proc *p, segment_callback func, void *closure, int writable)
1199 {
1200 int error = 0;
1201 vm_map_t map = &p->p_vmspace->vm_map;
1202 vm_map_entry_t entry;
1203
1204 for (entry = map->header.next; error == 0 && entry != &map->header;
1205 entry = entry->next) {
1206 vm_object_t obj;
1207 vm_object_t lobj;
1208 vm_object_t tobj;
1209
1210 /*
1211 * Don't dump inaccessible mappings, deal with legacy
1212 * coredump mode.
1213 *
1214 * Note that read-only segments related to the elf binary
1215 * are marked MAP_ENTRY_NOCOREDUMP now so we no longer
1216 * need to arbitrarily ignore such segments.
1217 */
1218 if (elf_legacy_coredump) {
1219 if (writable && (entry->protection & VM_PROT_RW) != VM_PROT_RW)
1220 continue;
1221 } else {
1222 if (writable && (entry->protection & VM_PROT_ALL) == 0)
1223 continue;
1224 }
1225
1226 /*
1227 * Dont include memory segment in the coredump if
1228 * MAP_NOCORE is set in mmap(2) or MADV_NOCORE in
1229 * madvise(2).
1230 *
1231 * Currently we only dump normal VM object maps. We do
1232 * not dump submaps or virtual page tables.
1233 */
1234 if (writable && (entry->eflags & MAP_ENTRY_NOCOREDUMP))
1235 continue;
1236 if (entry->maptype != VM_MAPTYPE_NORMAL)
1237 continue;
1238 if ((obj = entry->object.vm_object) == NULL)
1239 continue;
1240
1241 /*
1242 * Find the bottom-most object, leaving the base object
1243 * and the bottom-most object held (but only one hold
1244 * if they happen to be the same).
1245 */
1246 vm_object_hold_shared(obj);
1247
1248 lobj = obj;
1249 while (lobj && (tobj = lobj->backing_object) != NULL) {
1250 KKASSERT(tobj != obj);
1251 vm_object_hold_shared(tobj);
1252 if (tobj == lobj->backing_object) {
1253 if (lobj != obj) {
1254 vm_object_lock_swap();
1255 vm_object_drop(lobj);
1256 }
1257 lobj = tobj;
1258 } else {
1259 vm_object_drop(tobj);
1260 }
1261 }
1262
1263 /*
1264 * The callback only applies to default, swap, or vnode
1265 * objects. Other types of objects such as memory-mapped
1266 * devices are ignored.
1267 */
1268 if (lobj->type == OBJT_DEFAULT || lobj->type == OBJT_SWAP ||
1269 lobj->type == OBJT_VNODE) {
1270 error = (*func)(entry, closure);
1271 }
1272 if (lobj != obj)
1273 vm_object_drop(lobj);
1274 vm_object_drop(obj);
1275 }
1276 return (error);
1277 }
1278
1279 static
1280 void *
1281 target_reserve(elf_buf_t target, size_t bytes, int *error)
1282 {
1283 void *res = NULL;
1284
1285 if (target->buf) {
1286 if (target->off + bytes > target->off_max)
1287 *error = EINVAL;
1288 else
1289 res = target->buf + target->off;
1290 }
1291 target->off += bytes;
1292 return (res);
1293 }
1294
1295 /*
1296 * Write the core file header to the file, including padding up to
1297 * the page boundary.
1298 */
1299 static int
1300 __elfN(corehdr)(struct lwp *lp, int sig, struct file *fp, struct ucred *cred,
1301 int numsegs, elf_buf_t target)
1302 {
1303 int error;
1304 ssize_t nbytes;
1305
1306 /*
1307 * Fill in the header. The fp is passed so we can detect and flag
1308 * a checkpoint file pointer within the core file itself, because
1309 * it may not be restored from the same file handle.
1310 */
1311 error = __elfN(puthdr)(lp, target, sig, WRITE, numsegs, fp);
1312
1313 /* Write it to the core file. */
1314 if (error == 0) {
1315 error = fp_write(fp, target->buf, target->off, &nbytes,
1316 UIO_SYSSPACE);
1317 }
1318 return (error);
1319 }
1320
1321 static int
1322 __elfN(puthdr)(struct lwp *lp, elf_buf_t target, int sig, enum putmode mode,
1323 int numsegs, struct file *fp)
1324 {
1325 struct proc *p = lp->lwp_proc;
1326 int error = 0;
1327 size_t phoff;
1328 size_t noteoff;
1329 size_t notesz;
1330 Elf_Ehdr *ehdr;
1331 Elf_Phdr *phdr;
1332
1333 ehdr = target_reserve(target, sizeof(Elf_Ehdr), &error);
1334
1335 phoff = target->off;
1336 phdr = target_reserve(target, (numsegs + 1) * sizeof(Elf_Phdr), &error);
1337
1338 noteoff = target->off;
1339 if (error == 0)
1340 elf_putallnotes(lp, target, sig, mode);
1341 notesz = target->off - noteoff;
1342
1343 /*
1344 * put extra cruft for dumping process state here
1345 * - we really want it be before all the program
1346 * mappings
1347 * - we just need to update the offset accordingly
1348 * and GDB will be none the wiser.
1349 */
1350 if (error == 0)
1351 error = elf_puttextvp(p, target);
1352 if (error == 0)
1353 error = elf_putsigs(lp, target);
1354 if (error == 0)
1355 error = elf_putfiles(p, target, fp);
1356
1357 /*
1358 * Align up to a page boundary for the program segments. The
1359 * actual data will be written to the outptu file, not to elf_buf_t,
1360 * so we do not have to do any further bounds checking.
1361 */
1362 target->off = round_page(target->off);
1363 if (error == 0 && ehdr != NULL) {
1364 /*
1365 * Fill in the ELF header.
1366 */
1367 ehdr->e_ident[EI_MAG0] = ELFMAG0;
1368 ehdr->e_ident[EI_MAG1] = ELFMAG1;
1369 ehdr->e_ident[EI_MAG2] = ELFMAG2;
1370 ehdr->e_ident[EI_MAG3] = ELFMAG3;
1371 ehdr->e_ident[EI_CLASS] = ELF_CLASS;
1372 ehdr->e_ident[EI_DATA] = ELF_DATA;
1373 ehdr->e_ident[EI_VERSION] = EV_CURRENT;
1374 ehdr->e_ident[EI_OSABI] = ELFOSABI_NONE;
1375 ehdr->e_ident[EI_ABIVERSION] = 0;
1376 ehdr->e_ident[EI_PAD] = 0;
1377 ehdr->e_type = ET_CORE;
1378 ehdr->e_machine = ELF_ARCH;
1379 ehdr->e_version = EV_CURRENT;
1380 ehdr->e_entry = 0;
1381 ehdr->e_phoff = phoff;
1382 ehdr->e_flags = 0;
1383 ehdr->e_ehsize = sizeof(Elf_Ehdr);
1384 ehdr->e_phentsize = sizeof(Elf_Phdr);
1385 ehdr->e_phnum = numsegs + 1;
1386 ehdr->e_shentsize = sizeof(Elf_Shdr);
1387 ehdr->e_shnum = 0;
1388 ehdr->e_shstrndx = SHN_UNDEF;
1389 }
1390 if (error == 0 && phdr != NULL) {
1391 /*
1392 * Fill in the program header entries.
1393 */
1394 struct phdr_closure phc;
1395
1396 /* The note segement. */
1397 phdr->p_type = PT_NOTE;
1398 phdr->p_offset = noteoff;
1399 phdr->p_vaddr = 0;
1400 phdr->p_paddr = 0;
1401 phdr->p_filesz = notesz;
1402 phdr->p_memsz = 0;
1403 phdr->p_flags = 0;
1404 phdr->p_align = 0;
1405 ++phdr;
1406
1407 /* All the writable segments from the program. */
1408 phc.phdr = phdr;
1409 phc.phdr_max = phdr + numsegs;
1410 phc.offset = target->off;
1411 each_segment(p, cb_put_phdr, &phc, 1);
1412 }
1413 return (error);
1414 }
1415
1416 /*
1417 * Append core dump notes to target ELF buffer or simply update target size
1418 * if dryrun selected.
1419 */
1420 static int
1421 elf_putallnotes(struct lwp *corelp, elf_buf_t target, int sig,
1422 enum putmode mode)
1423 {
1424 struct proc *p = corelp->lwp_proc;
1425 int error;
1426 struct {
1427 prstatus_t status;
1428 prfpregset_t fpregs;
1429 prpsinfo_t psinfo;
1430 } *tmpdata;
1431 prstatus_t *status;
1432 prfpregset_t *fpregs;
1433 prpsinfo_t *psinfo;
1434 struct lwp *lp;
1435
1436 /*
1437 * Allocate temporary storage for notes on heap to avoid stack overflow.
1438 */
1439 if (mode != DRYRUN) {
1440 tmpdata = kmalloc(sizeof(*tmpdata), M_TEMP, M_ZERO | M_WAITOK);
1441 status = &tmpdata->status;
1442 fpregs = &tmpdata->fpregs;
1443 psinfo = &tmpdata->psinfo;
1444 } else {
1445 tmpdata = NULL;
1446 status = NULL;
1447 fpregs = NULL;
1448 psinfo = NULL;
1449 }
1450
1451 /*
1452 * Append LWP-agnostic note.
1453 */
1454 if (mode != DRYRUN) {
1455 psinfo->pr_version = PRPSINFO_VERSION;
1456 psinfo->pr_psinfosz = sizeof(prpsinfo_t);
1457 strlcpy(psinfo->pr_fname, p->p_comm,
1458 sizeof(psinfo->pr_fname));
1459 /*
1460 * XXX - We don't fill in the command line arguments
1461 * properly yet.
1462 */
1463 strlcpy(psinfo->pr_psargs, p->p_comm,
1464 sizeof(psinfo->pr_psargs));
1465 }
1466 error =
1467 __elfN(putnote)(target, "CORE", NT_PRPSINFO, psinfo, sizeof *psinfo);
1468 if (error)
1469 goto exit;
1470
1471 /*
1472 * Append first note for LWP that triggered core so that it is
1473 * the selected one when the debugger starts.
1474 */
1475 if (mode != DRYRUN) {
1476 status->pr_version = PRSTATUS_VERSION;
1477 status->pr_statussz = sizeof(prstatus_t);
1478 status->pr_gregsetsz = sizeof(gregset_t);
1479 status->pr_fpregsetsz = sizeof(fpregset_t);
1480 status->pr_osreldate = osreldate;
1481 status->pr_cursig = sig;
1482 /*
1483 * XXX GDB needs unique pr_pid for each LWP and does not
1484 * not support pr_pid==0 but lwp_tid can be 0, so hack unique
1485 * value.
1486 */
1487 status->pr_pid = corelp->lwp_tid;
1488 fill_regs(corelp, &status->pr_reg);
1489 fill_fpregs(corelp, fpregs);
1490 }
1491 error =
1492 __elfN(putnote)(target, "CORE", NT_PRSTATUS, status, sizeof *status);
1493 if (error)
1494 goto exit;
1495 error =
1496 __elfN(putnote)(target, "CORE", NT_FPREGSET, fpregs, sizeof *fpregs);
1497 if (error)
1498 goto exit;
1499
1500 /*
1501 * Then append notes for other LWPs.
1502 */
1503 FOREACH_LWP_IN_PROC(lp, p) {
1504 if (lp == corelp)
1505 continue;
1506 /* skip lwps being created */
1507 if (lp->lwp_thread == NULL)
1508 continue;
1509 if (mode != DRYRUN) {
1510 status->pr_pid = lp->lwp_tid;
1511 fill_regs(lp, &status->pr_reg);
1512 fill_fpregs(lp, fpregs);
1513 }
1514 error = __elfN(putnote)(target, "CORE", NT_PRSTATUS,
1515 status, sizeof *status);
1516 if (error)
1517 goto exit;
1518 error = __elfN(putnote)(target, "CORE", NT_FPREGSET,
1519 fpregs, sizeof *fpregs);
1520 if (error)
1521 goto exit;
1522 }
1523
1524 exit:
1525 if (tmpdata != NULL)
1526 kfree(tmpdata, M_TEMP);
1527 return (error);
1528 }
1529
1530 /*
1531 * Generate a note sub-structure.
1532 *
1533 * NOTE: 4-byte alignment.
1534 */
1535 static int
1536 __elfN(putnote)(elf_buf_t target, const char *name, int type,
1537 const void *desc, size_t descsz)
1538 {
1539 int error = 0;
1540 char *dst;
1541 Elf_Note note;
1542
1543 note.n_namesz = strlen(name) + 1;
1544 note.n_descsz = descsz;
1545 note.n_type = type;
1546 dst = target_reserve(target, sizeof(note), &error);
1547 if (dst != NULL)
1548 bcopy(&note, dst, sizeof note);
1549 dst = target_reserve(target, note.n_namesz, &error);
1550 if (dst != NULL)
1551 bcopy(name, dst, note.n_namesz);
1552 target->off = roundup2(target->off, sizeof(Elf_Word));
1553 dst = target_reserve(target, note.n_descsz, &error);
1554 if (dst != NULL)
1555 bcopy(desc, dst, note.n_descsz);
1556 target->off = roundup2(target->off, sizeof(Elf_Word));
1557 return (error);
1558 }
1559
1560
1561 static int
1562 elf_putsigs(struct lwp *lp, elf_buf_t target)
1563 {
1564 /* XXX lwp handle more than one lwp */
1565 struct proc *p = lp->lwp_proc;
1566 int error = 0;
1567 struct ckpt_siginfo *csi;
1568
1569 csi = target_reserve(target, sizeof(struct ckpt_siginfo), &error);
1570 if (csi) {
1571 csi->csi_ckptpisz = sizeof(struct ckpt_siginfo);
1572 bcopy(p->p_sigacts, &csi->csi_sigacts, sizeof(*p->p_sigacts));
1573 bcopy(&p->p_realtimer, &csi->csi_itimerval, sizeof(struct itimerval));
1574 bcopy(&lp->lwp_sigmask, &csi->csi_sigmask,
1575 sizeof(sigset_t));
1576 csi->csi_sigparent = p->p_sigparent;
1577 }
1578 return (error);
1579 }
1580
1581 static int
1582 elf_putfiles(struct proc *p, elf_buf_t target, struct file *ckfp)
1583 {
1584 int error = 0;
1585 int i;
1586 struct ckpt_filehdr *cfh = NULL;
1587 struct ckpt_fileinfo *cfi;
1588 struct file *fp;
1589 struct vnode *vp;
1590 /*
1591 * the duplicated loop is gross, but it was the only way
1592 * to eliminate uninitialized variable warnings
1593 */
1594 cfh = target_reserve(target, sizeof(struct ckpt_filehdr), &error);
1595 if (cfh) {
1596 cfh->cfh_nfiles = 0;
1597 }
1598
1599 /*
1600 * ignore STDIN/STDERR/STDOUT.
1601 */
1602 for (i = 3; error == 0 && i < p->p_fd->fd_nfiles; i++) {
1603 fp = holdfp(p->p_fd, i, -1);
1604 if (fp == NULL)
1605 continue;
1606 /*
1607 * XXX Only checkpoint vnodes for now.
1608 */
1609 if (fp->f_type != DTYPE_VNODE) {
1610 fdrop(fp);
1611 continue;
1612 }
1613 cfi = target_reserve(target, sizeof(struct ckpt_fileinfo),
1614 &error);
1615 if (cfi == NULL) {
1616 fdrop(fp);
1617 continue;
1618 }
1619 cfi->cfi_index = -1;
1620 cfi->cfi_type = fp->f_type;
1621 cfi->cfi_flags = fp->f_flag;
1622 cfi->cfi_offset = fp->f_offset;
1623 cfi->cfi_ckflags = 0;
1624
1625 if (fp == ckfp)
1626 cfi->cfi_ckflags |= CKFIF_ISCKPTFD;
1627 /* f_count and f_msgcount should not be saved/restored */
1628 /* XXX save cred info */
1629
1630 switch(fp->f_type) {
1631 case DTYPE_VNODE:
1632 vp = (struct vnode *)fp->f_data;
1633 /*
1634 * it looks like a bug in ptrace is marking
1635 * a non-vnode as a vnode - until we find the
1636 * root cause this will at least prevent
1637 * further panics from truss
1638 */
1639 if (vp == NULL || vp->v_mount == NULL)
1640 break;
1641 cfh->cfh_nfiles++;
1642 cfi->cfi_index = i;
1643 cfi->cfi_fh.fh_fsid = vp->v_mount->mnt_stat.f_fsid;
1644 error = VFS_VPTOFH(vp, &cfi->cfi_fh.fh_fid);
1645 break;
1646 default:
1647 break;
1648 }
1649 fdrop(fp);
1650 }
1651 return (error);
1652 }
1653
1654 static int
1655 elf_puttextvp(struct proc *p, elf_buf_t target)
1656 {
1657 int error = 0;
1658 int *vn_count;
1659 struct fp_closure fpc;
1660 struct ckpt_vminfo *vminfo;
1661
1662 vminfo = target_reserve(target, sizeof(struct ckpt_vminfo), &error);
1663 if (vminfo != NULL) {
1664 vminfo->cvm_dsize = p->p_vmspace->vm_dsize;
1665 vminfo->cvm_tsize = p->p_vmspace->vm_tsize;
1666 vminfo->cvm_daddr = p->p_vmspace->vm_daddr;
1667 vminfo->cvm_taddr = p->p_vmspace->vm_taddr;
1668 }
1669
1670 fpc.count = 0;
1671 vn_count = target_reserve(target, sizeof(int), &error);
1672 if (target->buf != NULL) {
1673 fpc.vnh = (struct vn_hdr *)(target->buf + target->off);
1674 fpc.vnh_max = fpc.vnh +
1675 (target->off_max - target->off) / sizeof(struct vn_hdr);
1676 error = each_segment(p, cb_put_fp, &fpc, 0);
1677 if (vn_count)
1678 *vn_count = fpc.count;
1679 } else {
1680 error = each_segment(p, cb_fpcount_segment, &fpc.count, 0);
1681 }
1682 target->off += fpc.count * sizeof(struct vn_hdr);
1683 return (error);
1684 }
1685
1686 /*
1687 * Try to find the appropriate ABI-note section for checknote,
1688 * The entire image is searched if necessary, not only the first page.
1689 */
1690 static boolean_t
1691 __elfN(check_note)(struct image_params *imgp, Elf_Brandnote *checknote,
1692 int32_t *osrel)
1693 {
1694 boolean_t valid_note_found;
1695 const Elf_Phdr *phdr, *pnote;
1696 const Elf_Ehdr *hdr;
1697 int i;
1698
1699 valid_note_found = FALSE;
1700 hdr = (const Elf_Ehdr *)imgp->image_header;
1701 phdr = (const Elf_Phdr *)(imgp->image_header + hdr->e_phoff);
1702
1703 for (i = 0; i < hdr->e_phnum; i++) {
1704 if (phdr[i].p_type == PT_NOTE) {
1705 pnote = &phdr[i];
1706 valid_note_found = check_PT_NOTE (imgp, checknote,
1707 osrel, pnote);
1708 if (valid_note_found)
1709 break;
1710 }
1711 }
1712 return valid_note_found;
1713 }
1714
1715 /*
1716 * Be careful not to create new overflow conditions when checking
1717 * for overflow.
1718 */
1719 static boolean_t
1720 note_overflow(const Elf_Note *note, size_t maxsize)
1721 {
1722 if (sizeof(*note) > maxsize)
1723 return TRUE;
1724 if (note->n_namesz > maxsize - sizeof(*note))
1725 return TRUE;
1726 return FALSE;
1727 }
1728
1729 static boolean_t
1730 hdr_overflow(__ElfN(Off) off_beg, __ElfN(Size) size)
1731 {
1732 __ElfN(Off) off_end;
1733
1734 off_end = off_beg + size;
1735 if (off_end < off_beg)
1736 return TRUE;
1737 return FALSE;
1738 }
1739
1740 static boolean_t
1741 check_PT_NOTE(struct image_params *imgp, Elf_Brandnote *checknote,
1742 int32_t *osrel, const Elf_Phdr * pnote)
1743 {
1744 boolean_t limited_to_first_page;
1745 boolean_t found = FALSE;
1746 const Elf_Note *note, *note0, *note_end;
1747 const char *note_name;
1748 __ElfN(Off) noteloc, firstloc;
1749 __ElfN(Size) notesz, firstlen, endbyte;
1750 struct lwbuf *lwb;
1751 struct lwbuf lwb_cache;
1752 const char *page;
1753 char *data = NULL;
1754 int n;
1755
1756 if (hdr_overflow(pnote->p_offset, pnote->p_filesz))
1757 return (FALSE);
1758 notesz = pnote->p_filesz;
1759 noteloc = pnote->p_offset;
1760 endbyte = noteloc + notesz;
1761 limited_to_first_page = noteloc < PAGE_SIZE && endbyte < PAGE_SIZE;
1762
1763 if (limited_to_first_page) {
1764 note = (const Elf_Note *)(imgp->image_header + noteloc);
1765 note_end = (const Elf_Note *)(imgp->image_header + endbyte);
1766 note0 = note;
1767 } else {
1768 firstloc = noteloc & PAGE_MASK;
1769 firstlen = PAGE_SIZE - firstloc;
1770 if (notesz < sizeof(Elf_Note) || notesz > PAGE_SIZE)
1771 return (FALSE);
1772
1773 lwb = &lwb_cache;
1774 if (exec_map_page(imgp, noteloc >> PAGE_SHIFT, &lwb, &page))
1775 return (FALSE);
1776 if (firstlen < notesz) { /* crosses page boundary */
1777 data = kmalloc(notesz, M_TEMP, M_WAITOK);
1778 bcopy(page + firstloc, data, firstlen);
1779
1780 exec_unmap_page(lwb);
1781 lwb = &lwb_cache;
1782 if (exec_map_page(imgp, (noteloc >> PAGE_SHIFT) + 1,
1783 &lwb, &page)) {
1784 kfree(data, M_TEMP);
1785 return (FALSE);
1786 }
1787 bcopy(page, data + firstlen, notesz - firstlen);
1788 note = note0 = (const Elf_Note *)(data);
1789 note_end = (const Elf_Note *)(data + notesz);
1790 } else {
1791 note = note0 = (const Elf_Note *)(page + firstloc);
1792 note_end = (const Elf_Note *)(page + firstloc +
1793 firstlen);
1794 }
1795 }
1796
1797 for (n = 0; n < 100 && note >= note0 && note < note_end; n++) {
1798 if (!aligned(note, Elf32_Addr))
1799 break;
1800 if (note_overflow(note, (const char *)note_end -
1801 (const char *)note)) {
1802 break;
1803 }
1804 note_name = (const char *)(note + 1);
1805
1806 if (note->n_namesz == checknote->hdr.n_namesz
1807 && note->n_descsz == checknote->hdr.n_descsz
1808 && note->n_type == checknote->hdr.n_type
1809 && (strncmp(checknote->vendor, note_name,
1810 checknote->hdr.n_namesz) == 0)) {
1811 /* Fetch osreldata from ABI.note-tag */
1812 if ((checknote->flags & BN_TRANSLATE_OSREL) != 0 &&
1813 checknote->trans_osrel != NULL)
1814 checknote->trans_osrel(note, osrel);
1815 found = TRUE;
1816 break;
1817 }
1818 note = (const Elf_Note *)((const char *)(note + 1) +
1819 roundup2(note->n_namesz, sizeof(Elf32_Addr)) +
1820 roundup2(note->n_descsz, sizeof(Elf32_Addr)));
1821 }
1822
1823 if (!limited_to_first_page) {
1824 if (data != NULL)
1825 kfree(data, M_TEMP);
1826 exec_unmap_page(lwb);
1827 }
1828 return (found);
1829 }
1830
1831 /*
1832 * The interpreter program header may be located beyond the first page, so
1833 * regardless of its location, a copy of the interpreter path is created so
1834 * that it may be safely referenced by the calling function in all case. The
1835 * memory is allocated by calling function, and the copying is done here.
1836 */
1837 static boolean_t
1838 extract_interpreter(struct image_params *imgp, const Elf_Phdr *pinterpreter,
1839 char *data)
1840 {
1841 boolean_t limited_to_first_page;
1842 const boolean_t result_success = FALSE;
1843 const boolean_t result_failure = TRUE;
1844 __ElfN(Off) pathloc, firstloc;
1845 __ElfN(Size) pathsz, firstlen, endbyte;
1846 struct lwbuf *lwb;
1847 struct lwbuf lwb_cache;
1848 const char *page;
1849
1850 if (hdr_overflow(pinterpreter->p_offset, pinterpreter->p_filesz))
1851 return (result_failure);
1852 pathsz = pinterpreter->p_filesz;
1853 pathloc = pinterpreter->p_offset;
1854 endbyte = pathloc + pathsz;
1855
1856 limited_to_first_page = pathloc < PAGE_SIZE && endbyte < PAGE_SIZE;
1857 if (limited_to_first_page) {
1858 bcopy(imgp->image_header + pathloc, data, pathsz);
1859 return (result_success);
1860 }
1861
1862 firstloc = pathloc & PAGE_MASK;
1863 firstlen = PAGE_SIZE - firstloc;
1864
1865 lwb = &lwb_cache;
1866 if (exec_map_page(imgp, pathloc >> PAGE_SHIFT, &lwb, &page))
1867 return (result_failure);
1868
1869 if (firstlen < pathsz) { /* crosses page boundary */
1870 bcopy(page + firstloc, data, firstlen);
1871
1872 exec_unmap_page(lwb);
1873 lwb = &lwb_cache;
1874 if (exec_map_page(imgp, (pathloc >> PAGE_SHIFT) + 1, &lwb,
1875 &page))
1876 return (result_failure);
1877 bcopy(page, data + firstlen, pathsz - firstlen);
1878 } else
1879 bcopy(page + firstloc, data, pathsz);
1880
1881 exec_unmap_page(lwb);
1882 return (result_success);
1883 }
1884
1885 static boolean_t
1886 __elfN(bsd_trans_osrel)(const Elf_Note *note, int32_t *osrel)
1887 {
1888 uintptr_t p;
1889
1890 p = (uintptr_t)(note + 1);
1891 p += roundup2(note->n_namesz, sizeof(Elf32_Addr));
1892 *osrel = *(const int32_t *)(p);
1893
1894 return (TRUE);
1895 }
1896
1897 /*
1898 * Tell kern_execve.c about it, with a little help from the linker.
1899 */
1900 #if defined(__x86_64__)
1901 static struct execsw elf_execsw = {exec_elf64_imgact, "ELF64"};
1902 EXEC_SET_ORDERED(elf64, elf_execsw, SI_ORDER_FIRST);
1903 #else /* i386 assumed */
1904 static struct execsw elf_execsw = {exec_elf32_imgact, "ELF32"};
1905 EXEC_SET_ORDERED(elf32, elf_execsw, SI_ORDER_FIRST);
1906 #endif
1907
1908 static vm_prot_t
1909 __elfN(trans_prot)(Elf_Word flags)
1910 {
1911 vm_prot_t prot;
1912
1913 prot = 0;
1914 if (flags & PF_X)
1915 prot |= VM_PROT_EXECUTE;
1916 if (flags & PF_W)
1917 prot |= VM_PROT_WRITE;
1918 if (flags & PF_R)
1919 prot |= VM_PROT_READ;
1920 return (prot);
1921 }
1922
1923 static Elf_Word
1924 __elfN(untrans_prot)(vm_prot_t prot)
1925 {
1926 Elf_Word flags;
1927
1928 flags = 0;
1929 if (prot & VM_PROT_EXECUTE)
1930 flags |= PF_X;
1931 if (prot & VM_PROT_READ)
1932 flags |= PF_R;
1933 if (prot & VM_PROT_WRITE)
1934 flags |= PF_W;
1935 return (flags);
1936 }
1937
1938 static u_long
1939 pie_base_hint(struct proc *p)
1940 {
1941 u_long base;
1942
1943 if (elf_pie_base_mmap)
1944 base = vm_map_hint(p, 0, VM_PROT_READ | VM_PROT_EXECUTE);
1945 else
1946 base = ET_DYN_LOAD_ADDR;
1947 return base;
1948 }
DragonFly BSD