core_elf32.c revision 1.36.6.2 1 /* $NetBSD: core_elf32.c,v 1.36.6.2 2017/12/03 11:38:44 jdolecek Exp $ */
2
3 /*
4 * Copyright (c) 2001 Wasabi Systems, Inc.
5 * All rights reserved.
6 *
7 * Written by Jason R. Thorpe for Wasabi Systems, Inc.
8 *
9 * Redistribution and use in source and binary forms, with or without
10 * modification, are permitted provided that the following conditions
11 * are met:
12 * 1. Redistributions of source code must retain the above copyright
13 * notice, this list of conditions and the following disclaimer.
14 * 2. Redistributions in binary form must reproduce the above copyright
15 * notice, this list of conditions and the following disclaimer in the
16 * documentation and/or other materials provided with the distribution.
17 * 3. All advertising materials mentioning features or use of this software
18 * must display the following acknowledgement:
19 * This product includes software developed for the NetBSD Project by
20 * Wasabi Systems, Inc.
21 * 4. The name of Wasabi Systems, Inc. may not be used to endorse
22 * or promote products derived from this software without specific prior
23 * written permission.
24 *
25 * THIS SOFTWARE IS PROVIDED BY WASABI SYSTEMS, INC. ``AS IS'' AND
26 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
27 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
28 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL WASABI SYSTEMS, INC
29 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
30 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
31 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
32 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
33 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
34 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
35 * POSSIBILITY OF SUCH DAMAGE.
36 */
37
38 /*
39 * core_elf32.c/core_elf64.c: Support for the Elf32/Elf64 core file format.
40 */
41
42 #include <sys/cdefs.h>
43 __KERNEL_RCSID(1, "$NetBSD: core_elf32.c,v 1.36.6.2 2017/12/03 11:38:44 jdolecek Exp $");
44
45 #ifdef _KERNEL_OPT
46 #include "opt_coredump.h"
47 #include "opt_compat_netbsd32.h"
48 #endif
49
50 #ifndef ELFSIZE
51 #define ELFSIZE 32
52 #endif
53
54 #include <sys/param.h>
55 #include <sys/systm.h>
56 #include <sys/proc.h>
57 #include <sys/vnode.h>
58 #include <sys/exec.h>
59 #include <sys/exec_elf.h>
60 #include <sys/ptrace.h>
61 #include <sys/kmem.h>
62 #include <sys/kauth.h>
63
64 #include <machine/reg.h>
65
66 #include <uvm/uvm_extern.h>
67
68 #ifdef COREDUMP
69
70 struct writesegs_state {
71 Elf_Phdr *psections;
72 proc_t *p;
73 off_t secoff;
74 size_t npsections;
75 };
76
77 /*
78 * We need to know how big the 'notes' are before we write the main header.
79 * To avoid problems with double-processing we save the data.
80 */
81 struct note_buf {
82 struct note_buf *nb_next;
83 unsigned char nb_data[4096 - sizeof (void *)];
84 };
85
86 struct note_state {
87 struct note_buf *ns_first;
88 struct note_buf *ns_last;
89 unsigned int ns_count; /* Of full buffers */
90 unsigned int ns_offset; /* Write point in last buffer */
91 };
92
93 static int ELFNAMEEND(coredump_getseghdrs)(struct uvm_coredump_state *);
94
95 static int ELFNAMEEND(coredump_notes)(struct lwp *, struct note_state *);
96 static int ELFNAMEEND(coredump_note)(struct lwp *, struct note_state *);
97
98 /* The 'note' section names and data are always 4-byte aligned. */
99 #define ELFROUNDSIZE 4 /* XXX Should it be sizeof(Elf_Word)? */
100
101 #define elf_process_read_regs CONCAT(process_read_regs, ELFSIZE)
102 #define elf_process_read_fpregs CONCAT(process_read_fpregs, ELFSIZE)
103 #define elf_reg CONCAT(process_reg, ELFSIZE)
104 #define elf_fpreg CONCAT(process_fpreg, ELFSIZE)
105
106 int
107 ELFNAMEEND(coredump)(struct lwp *l, struct coredump_iostate *cookie)
108 {
109 Elf_Ehdr ehdr;
110 Elf_Shdr shdr;
111 Elf_Phdr *psections;
112 size_t psectionssize;
113 int npsections;
114 struct writesegs_state ws;
115 off_t notestart;
116 size_t notesize;
117 int error, i;
118
119 struct note_state ns;
120 struct note_buf *nb;
121
122 psections = NULL;
123
124 /* Get all of the notes (mostly all the registers). */
125 ns.ns_first = kmem_alloc(sizeof *ns.ns_first, KM_SLEEP);
126 ns.ns_last = ns.ns_first;
127 ns.ns_count = 0;
128 ns.ns_offset = 0;
129 error = ELFNAMEEND(coredump_notes)(l, &ns);
130 ns.ns_last->nb_next = NULL;
131 if (error)
132 goto out;
133 notesize = ns.ns_count * sizeof nb->nb_data + ns.ns_offset;
134
135 /*
136 * We have to make a total of 3 passes across the map:
137 *
138 * 1. Count the number of map entries (the number of
139 * PT_LOAD sections in the dump).
140 *
141 * 2. Write the P-section headers.
142 *
143 * 3. Write the P-sections.
144 */
145
146 /* Pass 1: count the entries. */
147 npsections = uvm_coredump_count_segs(l->l_proc);
148 /* Allow for the PT_NOTE section. */
149 npsections++;
150
151 /* Build the main elf header */
152 memset(&ehdr.e_ident[EI_PAD], 0, sizeof(ehdr.e_ident) - EI_PAD);
153 memcpy(ehdr.e_ident, ELFMAG, SELFMAG);
154 #if ELFSIZE == 32
155 ehdr.e_ident[EI_CLASS] = ELFCLASS32;
156 #elif ELFSIZE == 64
157 ehdr.e_ident[EI_CLASS] = ELFCLASS64;
158 #endif
159 ehdr.e_ident[EI_DATA] = ELFDEFNNAME(MACHDEP_ENDIANNESS);
160 ehdr.e_ident[EI_VERSION] = EV_CURRENT;
161 /*
162 * NetBSD sets generic SYSV OSABI and ABI version 0
163 * Native ELF files are distinguishable with NetBSD specific notes
164 */
165 ehdr.e_ident[EI_OSABI] = ELFOSABI_SYSV;
166 ehdr.e_ident[EI_ABIVERSION] = 0;
167
168 ehdr.e_type = ET_CORE;
169 /* XXX This should be the e_machine of the executable. */
170 ehdr.e_machine = ELFDEFNNAME(MACHDEP_ID);
171 ehdr.e_version = EV_CURRENT;
172 ehdr.e_entry = 0;
173 ehdr.e_flags = 0;
174 ehdr.e_ehsize = sizeof(ehdr);
175 ehdr.e_phentsize = sizeof(Elf_Phdr);
176 if (npsections < PN_XNUM) {
177 ehdr.e_phnum = npsections;
178 ehdr.e_shentsize = 0;
179 ehdr.e_shnum = 0;
180 ehdr.e_shoff = 0;
181 ehdr.e_phoff = sizeof(ehdr);
182 } else {
183 ehdr.e_phnum = PN_XNUM;
184 ehdr.e_shentsize = sizeof(Elf_Shdr);
185 ehdr.e_shnum = 1;
186 ehdr.e_shoff = sizeof(ehdr);
187 ehdr.e_phoff = sizeof(ehdr) + sizeof(shdr);
188 }
189 ehdr.e_shstrndx = 0;
190
191 #ifdef ELF_MD_COREDUMP_SETUP
192 ELF_MD_COREDUMP_SETUP(l, &ehdr);
193 #endif
194
195 /* Write out the ELF header. */
196 error = coredump_write(cookie, UIO_SYSSPACE, &ehdr, sizeof(ehdr));
197 if (error)
198 goto out;
199
200 /* Write out sections, if needed */
201 if (npsections >= PN_XNUM) {
202 memset(&shdr, 0, sizeof(shdr));
203 shdr.sh_type = SHT_NULL;
204 shdr.sh_info = npsections;
205 error = coredump_write(cookie, UIO_SYSSPACE, &shdr,
206 sizeof(shdr));
207 if (error)
208 goto out;
209 }
210
211 psectionssize = npsections * sizeof(*psections);
212 notestart = ehdr.e_phoff + psectionssize;
213
214 psections = kmem_zalloc(psectionssize, KM_SLEEP);
215
216 /* Pass 2: now find the P-section headers. */
217 ws.secoff = notestart + notesize;
218 ws.psections = psections;
219 ws.npsections = npsections - 1;
220 ws.p = l->l_proc;
221 error = uvm_coredump_walkmap(l->l_proc, ELFNAMEEND(coredump_getseghdrs),
222 &ws);
223 if (error)
224 goto out;
225 if (ws.npsections != 0) {
226 /* A section went away */
227 error = ENOMEM;
228 goto out;
229 }
230
231 /* Add the PT_NOTE header after the P-section headers. */
232 ws.psections->p_type = PT_NOTE;
233 ws.psections->p_offset = notestart;
234 ws.psections->p_vaddr = 0;
235 ws.psections->p_paddr = 0;
236 ws.psections->p_filesz = notesize;
237 ws.psections->p_memsz = 0;
238 ws.psections->p_flags = PF_R;
239 ws.psections->p_align = ELFROUNDSIZE;
240
241 /* Write the P-section headers followed by the PT_NOTE header */
242 error = coredump_write(cookie, UIO_SYSSPACE, psections, psectionssize);
243 if (error)
244 goto out;
245
246 #ifdef DIAGNOSTIC
247 if (coredump_offset(cookie) != notestart)
248 panic("coredump: offset %lld != notestart %lld",
249 (long long) coredump_offset(cookie),
250 (long long) notestart);
251 #endif
252
253 /* Write out the notes. */
254 for (nb = ns.ns_first; nb != NULL; nb = nb->nb_next) {
255 error = coredump_write(cookie, UIO_SYSSPACE, nb->nb_data,
256 nb->nb_next == NULL ? ns.ns_offset : sizeof nb->nb_data);
257 if (error)
258 goto out;
259 }
260
261 /* Finally, write the sections themselves. */
262 for (i = 0; i < npsections - 1; i++) {
263 if (psections[i].p_filesz == 0)
264 continue;
265
266 #ifdef DIAGNOSTIC
267 if (coredump_offset(cookie) != psections[i].p_offset)
268 panic("coredump: offset %lld != p_offset[%d] %lld",
269 (long long) coredump_offset(cookie), i,
270 (long long) psections[i].p_filesz);
271 #endif
272
273 error = coredump_write(cookie, UIO_USERSPACE,
274 (void *)(vaddr_t)psections[i].p_vaddr,
275 psections[i].p_filesz);
276 if (error)
277 goto out;
278 }
279
280 out:
281 if (psections)
282 kmem_free(psections, psectionssize);
283 while ((nb = ns.ns_first) != NULL) {
284 ns.ns_first = nb->nb_next;
285 kmem_free(nb, sizeof *nb);
286 }
287 return (error);
288 }
289
290 static int
291 ELFNAMEEND(coredump_getseghdrs)(struct uvm_coredump_state *us)
292 {
293 struct writesegs_state *ws = us->cookie;
294 Elf_Phdr phdr;
295 vsize_t size, realsize;
296 vaddr_t end;
297 int error;
298
299 /* Don't overrun if there are more sections */
300 if (ws->npsections == 0)
301 return ENOMEM;
302 ws->npsections--;
303
304 size = us->end - us->start;
305 realsize = us->realend - us->start;
306 end = us->realend;
307
308 /* Don't bother writing out trailing zeros */
309 while (realsize > 0) {
310 long buf[1024 / sizeof(long)];
311 size_t slen = realsize > sizeof(buf) ? sizeof(buf) : realsize;
312 const long *ep;
313 int i;
314
315 end -= slen;
316 if ((error = copyin_proc(ws->p, (void *)end, buf, slen)) != 0)
317 return error;
318
319 ep = (const long *) &buf[slen / sizeof(buf[0])];
320 for (i = 0, ep--; buf <= ep; ep--, i++) {
321 if (*ep)
322 break;
323 }
324 realsize -= i * sizeof(buf[0]);
325 if (i * sizeof(buf[0]) < slen)
326 break;
327 }
328
329 phdr.p_type = PT_LOAD;
330 phdr.p_offset = ws->secoff;
331 phdr.p_vaddr = us->start;
332 phdr.p_paddr = 0;
333 phdr.p_filesz = realsize;
334 phdr.p_memsz = size;
335 phdr.p_flags = 0;
336 if (us->prot & VM_PROT_READ)
337 phdr.p_flags |= PF_R;
338 if (us->prot & VM_PROT_WRITE)
339 phdr.p_flags |= PF_W;
340 if (us->prot & VM_PROT_EXECUTE)
341 phdr.p_flags |= PF_X;
342 phdr.p_align = PAGE_SIZE;
343
344 ws->secoff += phdr.p_filesz;
345 *ws->psections++ = phdr;
346
347 return (0);
348 }
349
350 static void
351 coredump_note_procinfo(struct lwp *l, struct note_state *ns)
352 {
353 struct proc *p;
354 struct netbsd_elfcore_procinfo cpi;
355 struct lwp *l0;
356 sigset_t ss1, ss2;
357
358 p = l->l_proc;
359
360 /* First, write an elfcore_procinfo. */
361 cpi.cpi_version = NETBSD_ELFCORE_PROCINFO_VERSION;
362 cpi.cpi_cpisize = sizeof(cpi);
363 cpi.cpi_signo = p->p_sigctx.ps_info._signo;
364 cpi.cpi_sigcode = p->p_sigctx.ps_info._code;
365 cpi.cpi_siglwp = p->p_sigctx.ps_lwp;
366
367 /*
368 * XXX This should be per-LWP.
369 */
370 ss1 = p->p_sigpend.sp_set;
371 sigemptyset(&ss2);
372 LIST_FOREACH(l0, &p->p_lwps, l_sibling) {
373 sigplusset(&l0->l_sigpend.sp_set, &ss1);
374 sigplusset(&l0->l_sigmask, &ss2);
375 }
376 memcpy(&cpi.cpi_sigpend, &ss1, sizeof(cpi.cpi_sigpend));
377 memcpy(&cpi.cpi_sigmask, &ss2, sizeof(cpi.cpi_sigmask));
378 memcpy(&cpi.cpi_sigignore, &p->p_sigctx.ps_sigignore,
379 sizeof(cpi.cpi_sigignore));
380 memcpy(&cpi.cpi_sigcatch, &p->p_sigctx.ps_sigcatch,
381 sizeof(cpi.cpi_sigcatch));
382
383 cpi.cpi_pid = p->p_pid;
384 mutex_enter(proc_lock);
385 cpi.cpi_ppid = p->p_pptr->p_pid;
386 cpi.cpi_pgrp = p->p_pgid;
387 cpi.cpi_sid = p->p_session->s_sid;
388 mutex_exit(proc_lock);
389
390 cpi.cpi_ruid = kauth_cred_getuid(l->l_cred);
391 cpi.cpi_euid = kauth_cred_geteuid(l->l_cred);
392 cpi.cpi_svuid = kauth_cred_getsvuid(l->l_cred);
393
394 cpi.cpi_rgid = kauth_cred_getgid(l->l_cred);
395 cpi.cpi_egid = kauth_cred_getegid(l->l_cred);
396 cpi.cpi_svgid = kauth_cred_getsvgid(l->l_cred);
397
398 cpi.cpi_nlwps = p->p_nlwps;
399 (void)strncpy(cpi.cpi_name, p->p_comm, sizeof(cpi.cpi_name));
400 cpi.cpi_name[sizeof(cpi.cpi_name) - 1] = '\0';
401
402 ELFNAMEEND(coredump_savenote)(ns, ELF_NOTE_NETBSD_CORE_PROCINFO,
403 ELF_NOTE_NETBSD_CORE_NAME, &cpi, sizeof(cpi));
404 }
405
406 static int
407 coredump_note_auxv(struct lwp *l, struct note_state *ns)
408 {
409 int error;
410 size_t len;
411 void *kauxv;
412
413 if ((error = proc_getauxv(l->l_proc, &kauxv, &len)) != 0)
414 return error;
415
416 ELFNAMEEND(coredump_savenote)(ns, ELF_NOTE_NETBSD_CORE_AUXV,
417 ELF_NOTE_NETBSD_CORE_NAME, kauxv, len);
418
419 kmem_free(kauxv, len);
420 return 0;
421 }
422
423 static int
424 ELFNAMEEND(coredump_notes)(struct lwp *l, struct note_state *ns)
425 {
426 int error;
427 struct lwp *l0;
428 struct proc *p = l->l_proc;
429
430 coredump_note_procinfo(l, ns);
431 error = coredump_note_auxv(l, ns);
432 if (error)
433 return error;
434
435 /* XXX Add hook for machdep per-proc notes. */
436
437 /*
438 * Now write the register info for the thread that caused the
439 * coredump.
440 */
441 error = ELFNAMEEND(coredump_note)(l, ns);
442 if (error)
443 return error;
444
445 /*
446 * Now, for each LWP, write the register info and any other
447 * per-LWP notes.
448 * Lock in case this is a gcore requested dump.
449 */
450 mutex_enter(p->p_lock);
451 LIST_FOREACH(l0, &p->p_lwps, l_sibling) {
452 if (l0 == l) /* we've taken care of this thread */
453 continue;
454 error = ELFNAMEEND(coredump_note)(l0, ns);
455 if (error)
456 break;
457 }
458 mutex_exit(p->p_lock);
459
460 return error;
461 }
462
463 static int
464 ELFNAMEEND(coredump_note)(struct lwp *l, struct note_state *ns)
465 {
466 int error;
467 char name[64];
468 elf_reg intreg;
469 #ifdef PT_GETFPREGS
470 elf_fpreg freg;
471 size_t freglen;
472 #endif
473
474 snprintf(name, sizeof(name), "%s@%d",
475 ELF_NOTE_NETBSD_CORE_NAME, l->l_lid);
476
477 error = elf_process_read_regs(l, &intreg);
478 if (error)
479 return (error);
480
481 ELFNAMEEND(coredump_savenote)(ns, PT_GETREGS, name, &intreg,
482 sizeof(intreg));
483
484 #ifdef PT_GETFPREGS
485 freglen = sizeof(freg);
486 error = elf_process_read_fpregs(l, &freg, &freglen);
487 if (error)
488 return (error);
489
490 ELFNAMEEND(coredump_savenote)(ns, PT_GETFPREGS, name, &freg, freglen);
491 #endif
492 /* XXX Add hook for machdep per-LWP notes. */
493 return (0);
494 }
495
496 static void
497 save_note_bytes(struct note_state *ns, const void *data, size_t len)
498 {
499 struct note_buf *nb = ns->ns_last;
500 size_t copylen;
501 unsigned char *wp;
502
503 /*
504 * Just copy the data into a buffer list.
505 * All but the last buffer is full.
506 */
507 for (;;) {
508 copylen = min(len, sizeof nb->nb_data - ns->ns_offset);
509 wp = nb->nb_data + ns->ns_offset;
510 memcpy(wp, data, copylen);
511 if (copylen == len)
512 break;
513 nb->nb_next = kmem_alloc(sizeof *nb->nb_next, KM_SLEEP);
514 nb = nb->nb_next;
515 ns->ns_last = nb;
516 ns->ns_count++;
517 ns->ns_offset = 0;
518 len -= copylen;
519 data = (const unsigned char *)data + copylen;
520 }
521
522 while (copylen & (ELFROUNDSIZE - 1))
523 wp[copylen++] = 0;
524
525 ns->ns_offset += copylen;
526 }
527
528 void
529 ELFNAMEEND(coredump_savenote)(struct note_state *ns, unsigned int type,
530 const char *name, void *data, size_t data_len)
531 {
532 Elf_Nhdr nhdr;
533
534 nhdr.n_namesz = strlen(name) + 1;
535 nhdr.n_descsz = data_len;
536 nhdr.n_type = type;
537
538 save_note_bytes(ns, &nhdr, sizeof (nhdr));
539 save_note_bytes(ns, name, nhdr.n_namesz);
540 save_note_bytes(ns, data, data_len);
541 }
542
543 #else /* COREDUMP */
544
545 int
546 ELFNAMEEND(coredump)(struct lwp *l, struct coredump_iostate *cookie)
547 {
548
549 return ENOSYS;
550 }
551
552 #endif /* COREDUMP */
553