core_elf32.c revision 1.36.10.1 1 /* $NetBSD: core_elf32.c,v 1.36.10.1 2014/05/18 17:46:07 rmind 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 1.36.10.1 2014/05/18 17:46:07 rmind Exp $");
44
45 #ifdef _KERNEL_OPT
46 #include "opt_coredump.h"
47 #endif
48
49 #ifndef ELFSIZE
50 #define ELFSIZE 32
51 #endif
52
53 #include <sys/param.h>
54 #include <sys/systm.h>
55 #include <sys/proc.h>
56 #include <sys/vnode.h>
57 #include <sys/exec.h>
58 #include <sys/exec_elf.h>
59 #include <sys/ptrace.h>
60 #include <sys/kmem.h>
61 #include <sys/kauth.h>
62
63 #include <machine/reg.h>
64
65 #include <uvm/uvm_extern.h>
66
67 #ifdef COREDUMP
68
69 struct writesegs_state {
70 Elf_Phdr *psections;
71 proc_t *p;
72 off_t secoff;
73 size_t npsections;
74 };
75
76 /*
77 * We need to know how big the 'notes' are before we write the main header.
78 * To avoid problems with double-processing we save the data.
79 */
80 struct note_buf {
81 struct note_buf *nb_next;
82 unsigned char nb_data[4096 - sizeof (void *)];
83 };
84
85 struct note_state {
86 struct note_buf *ns_first;
87 struct note_buf *ns_last;
88 unsigned int ns_count; /* Of full buffers */
89 unsigned int ns_offset; /* Write point in last buffer */
90 };
91
92 static int ELFNAMEEND(coredump_getseghdrs)(struct uvm_coredump_state *);
93
94 static int ELFNAMEEND(coredump_notes)(struct lwp *, struct note_state *);
95 static int ELFNAMEEND(coredump_note)(struct lwp *, struct note_state *);
96
97 /* The 'note' section names and data are always 4-byte aligned. */
98 #define ELFROUNDSIZE 4 /* XXX Should it be sizeof(Elf_Word)? */
99
100 #define elf_process_read_regs CONCAT(process_read_regs, ELFSIZE)
101 #define elf_process_read_fpregs CONCAT(process_read_fpregs, ELFSIZE)
102 #define elf_reg CONCAT(process_reg, ELFSIZE)
103 #define elf_fpreg CONCAT(process_fpreg, ELFSIZE)
104
105 int
106 ELFNAMEEND(coredump)(struct lwp *l, struct coredump_iostate *cookie)
107 {
108 Elf_Ehdr ehdr;
109 Elf_Shdr shdr;
110 Elf_Phdr *psections;
111 size_t psectionssize;
112 int npsections;
113 struct writesegs_state ws;
114 off_t notestart;
115 size_t notesize;
116 int error, i;
117
118 struct note_state ns;
119 struct note_buf *nb;
120
121 psections = NULL;
122
123 /* Get all of the notes (mostly all the registers). */
124 ns.ns_first = kmem_alloc(sizeof *ns.ns_first, KM_SLEEP);
125 ns.ns_last = ns.ns_first;
126 ns.ns_count = 0;
127 ns.ns_offset = 0;
128 error = ELFNAMEEND(coredump_notes)(l, &ns);
129 ns.ns_last->nb_next = NULL;
130 if (error)
131 goto out;
132 notesize = ns.ns_count * sizeof nb->nb_data + ns.ns_offset;
133
134 /*
135 * We have to make a total of 3 passes across the map:
136 *
137 * 1. Count the number of map entries (the number of
138 * PT_LOAD sections in the dump).
139 *
140 * 2. Write the P-section headers.
141 *
142 * 3. Write the P-sections.
143 */
144
145 /* Pass 1: count the entries. */
146 npsections = uvm_coredump_count_segs(l->l_proc);
147 /* Allow for the PT_NOTE section. */
148 npsections++;
149
150 /* Build the main elf header */
151 memset(&ehdr.e_ident[EI_PAD], 0, sizeof(ehdr.e_ident) - EI_PAD);
152 memcpy(ehdr.e_ident, ELFMAG, SELFMAG);
153 #if ELFSIZE == 32
154 ehdr.e_ident[EI_CLASS] = ELFCLASS32;
155 #elif ELFSIZE == 64
156 ehdr.e_ident[EI_CLASS] = ELFCLASS64;
157 #endif
158 ehdr.e_ident[EI_DATA] = ELFDEFNNAME(MACHDEP_ENDIANNESS);
159 ehdr.e_ident[EI_VERSION] = EV_CURRENT;
160 /* XXX Should be the OSABI/ABI version of the executable. */
161 ehdr.e_ident[EI_OSABI] = ELFOSABI_SYSV;
162 ehdr.e_ident[EI_ABIVERSION] = 0;
163
164 ehdr.e_type = ET_CORE;
165 /* XXX This should be the e_machine of the executable. */
166 ehdr.e_machine = ELFDEFNNAME(MACHDEP_ID);
167 ehdr.e_version = EV_CURRENT;
168 ehdr.e_entry = 0;
169 ehdr.e_flags = 0;
170 ehdr.e_ehsize = sizeof(ehdr);
171 ehdr.e_phentsize = sizeof(Elf_Phdr);
172 if (npsections < PN_XNUM) {
173 ehdr.e_phnum = npsections;
174 ehdr.e_shentsize = 0;
175 ehdr.e_shnum = 0;
176 ehdr.e_shoff = 0;
177 ehdr.e_phoff = sizeof(ehdr);
178 } else {
179 ehdr.e_phnum = PN_XNUM;
180 ehdr.e_shentsize = sizeof(Elf_Shdr);
181 ehdr.e_shnum = 1;
182 ehdr.e_shoff = sizeof(ehdr);
183 ehdr.e_phoff = sizeof(ehdr) + sizeof(shdr);
184 }
185 ehdr.e_shstrndx = 0;
186
187 #ifdef ELF_MD_COREDUMP_SETUP
188 ELF_MD_COREDUMP_SETUP(l, &ehdr);
189 #endif
190
191 /* Write out the ELF header. */
192 error = coredump_write(cookie, UIO_SYSSPACE, &ehdr, sizeof(ehdr));
193 if (error)
194 goto out;
195
196 /* Write out sections, if needed */
197 if (npsections >= PN_XNUM) {
198 memset(&shdr, 0, sizeof(shdr));
199 shdr.sh_type = SHT_NULL;
200 shdr.sh_info = npsections;
201 error = coredump_write(cookie, UIO_SYSSPACE, &shdr,
202 sizeof(shdr));
203 if (error)
204 goto out;
205 }
206
207 psectionssize = npsections * sizeof(*psections);
208 notestart = ehdr.e_phoff + psectionssize;
209
210 psections = kmem_zalloc(psectionssize, KM_SLEEP);
211
212 /* Pass 2: now find the P-section headers. */
213 ws.secoff = notestart + notesize;
214 ws.psections = psections;
215 ws.npsections = npsections - 1;
216 ws.p = l->l_proc;
217 error = uvm_coredump_walkmap(l->l_proc, ELFNAMEEND(coredump_getseghdrs),
218 &ws);
219 if (error)
220 goto out;
221 if (ws.npsections != 0) {
222 /* A section went away */
223 error = ENOMEM;
224 goto out;
225 }
226
227 /* Add the PT_NOTE header after the P-section headers. */
228 ws.psections->p_type = PT_NOTE;
229 ws.psections->p_offset = notestart;
230 ws.psections->p_vaddr = 0;
231 ws.psections->p_paddr = 0;
232 ws.psections->p_filesz = notesize;
233 ws.psections->p_memsz = 0;
234 ws.psections->p_flags = PF_R;
235 ws.psections->p_align = ELFROUNDSIZE;
236
237 /* Write the P-section headers followed by the PT_NOTE header */
238 error = coredump_write(cookie, UIO_SYSSPACE, psections, psectionssize);
239 if (error)
240 goto out;
241
242 #ifdef DIAGNOSTIC
243 if (coredump_offset(cookie) != notestart)
244 panic("coredump: offset %lld != notestart %lld",
245 (long long) coredump_offset(cookie),
246 (long long) notestart);
247 #endif
248
249 /* Write out the notes. */
250 for (nb = ns.ns_first; nb != NULL; nb = nb->nb_next) {
251 error = coredump_write(cookie, UIO_SYSSPACE, nb->nb_data,
252 nb->nb_next == NULL ? ns.ns_offset : sizeof nb->nb_data);
253 if (error)
254 goto out;
255 }
256
257 /* Finally, write the sections themselves. */
258 for (i = 0; i < npsections - 1; i++) {
259 if (psections[i].p_filesz == 0)
260 continue;
261
262 #ifdef DIAGNOSTIC
263 if (coredump_offset(cookie) != psections[i].p_offset)
264 panic("coredump: offset %lld != p_offset[%d] %lld",
265 (long long) coredump_offset(cookie), i,
266 (long long) psections[i].p_filesz);
267 #endif
268
269 error = coredump_write(cookie, UIO_USERSPACE,
270 (void *)(vaddr_t)psections[i].p_vaddr,
271 psections[i].p_filesz);
272 if (error)
273 goto out;
274 }
275
276 out:
277 if (psections)
278 kmem_free(psections, psectionssize);
279 while ((nb = ns.ns_first) != NULL) {
280 ns.ns_first = nb->nb_next;
281 kmem_free(nb, sizeof *nb);
282 }
283 return (error);
284 }
285
286 static int
287 ELFNAMEEND(coredump_getseghdrs)(struct uvm_coredump_state *us)
288 {
289 struct writesegs_state *ws = us->cookie;
290 Elf_Phdr phdr;
291 vsize_t size, realsize;
292 vaddr_t end;
293 int error;
294
295 /* Don't overrun if there are more sections */
296 if (ws->npsections == 0)
297 return ENOMEM;
298 ws->npsections--;
299
300 size = us->end - us->start;
301 realsize = us->realend - us->start;
302 end = us->realend;
303
304 /* Don't bother writing out trailing zeros */
305 while (realsize > 0) {
306 long buf[1024 / sizeof(long)];
307 size_t slen = realsize > sizeof(buf) ? sizeof(buf) : realsize;
308 const long *ep;
309 int i;
310
311 end -= slen;
312 if ((error = copyin_proc(ws->p, (void *)end, buf, slen)) != 0)
313 return error;
314
315 ep = (const long *) &buf[slen / sizeof(buf[0])];
316 for (i = 0, ep--; buf <= ep; ep--, i++) {
317 if (*ep)
318 break;
319 }
320 realsize -= i * sizeof(buf[0]);
321 if (i * sizeof(buf[0]) < slen)
322 break;
323 }
324
325 phdr.p_type = PT_LOAD;
326 phdr.p_offset = ws->secoff;
327 phdr.p_vaddr = us->start;
328 phdr.p_paddr = 0;
329 phdr.p_filesz = realsize;
330 phdr.p_memsz = size;
331 phdr.p_flags = 0;
332 if (us->prot & VM_PROT_READ)
333 phdr.p_flags |= PF_R;
334 if (us->prot & VM_PROT_WRITE)
335 phdr.p_flags |= PF_W;
336 if (us->prot & VM_PROT_EXECUTE)
337 phdr.p_flags |= PF_X;
338 phdr.p_align = PAGE_SIZE;
339
340 ws->secoff += phdr.p_filesz;
341 *ws->psections++ = phdr;
342
343 return (0);
344 }
345
346 static int
347 ELFNAMEEND(coredump_notes)(struct lwp *l, struct note_state *ns)
348 {
349 struct proc *p;
350 struct netbsd_elfcore_procinfo cpi;
351 int error;
352 struct lwp *l0;
353 sigset_t ss1, ss2;
354
355 p = l->l_proc;
356
357 /* First, write an elfcore_procinfo. */
358 cpi.cpi_version = NETBSD_ELFCORE_PROCINFO_VERSION;
359 cpi.cpi_cpisize = sizeof(cpi);
360 cpi.cpi_signo = p->p_sigctx.ps_signo;
361 cpi.cpi_sigcode = p->p_sigctx.ps_code;
362 cpi.cpi_siglwp = p->p_sigctx.ps_lwp;
363
364 /*
365 * XXX This should be per-LWP.
366 */
367 ss1 = p->p_sigpend.sp_set;
368 sigemptyset(&ss2);
369 LIST_FOREACH(l0, &p->p_lwps, l_sibling) {
370 sigplusset(&l0->l_sigpend.sp_set, &ss1);
371 sigplusset(&l0->l_sigmask, &ss2);
372 }
373 memcpy(&cpi.cpi_sigpend, &ss1, sizeof(cpi.cpi_sigpend));
374 memcpy(&cpi.cpi_sigmask, &ss2, sizeof(cpi.cpi_sigmask));
375 memcpy(&cpi.cpi_sigignore, &p->p_sigctx.ps_sigignore,
376 sizeof(cpi.cpi_sigignore));
377 memcpy(&cpi.cpi_sigcatch, &p->p_sigctx.ps_sigcatch,
378 sizeof(cpi.cpi_sigcatch));
379
380 cpi.cpi_pid = p->p_pid;
381 mutex_enter(proc_lock);
382 cpi.cpi_ppid = p->p_pptr->p_pid;
383 cpi.cpi_pgrp = p->p_pgid;
384 cpi.cpi_sid = p->p_session->s_sid;
385 mutex_exit(proc_lock);
386
387 cpi.cpi_ruid = kauth_cred_getuid(l->l_cred);
388 cpi.cpi_euid = kauth_cred_geteuid(l->l_cred);
389 cpi.cpi_svuid = kauth_cred_getsvuid(l->l_cred);
390
391 cpi.cpi_rgid = kauth_cred_getgid(l->l_cred);
392 cpi.cpi_egid = kauth_cred_getegid(l->l_cred);
393 cpi.cpi_svgid = kauth_cred_getsvgid(l->l_cred);
394
395 cpi.cpi_nlwps = p->p_nlwps;
396 (void)strncpy(cpi.cpi_name, p->p_comm, sizeof(cpi.cpi_name));
397 cpi.cpi_name[sizeof(cpi.cpi_name) - 1] = '\0';
398
399 ELFNAMEEND(coredump_savenote)(ns, ELF_NOTE_NETBSD_CORE_PROCINFO,
400 ELF_NOTE_NETBSD_CORE_NAME, &cpi, sizeof(cpi));
401
402 /* XXX Add hook for machdep per-proc notes. */
403
404 /*
405 * Now write the register info for the thread that caused the
406 * coredump.
407 */
408 error = ELFNAMEEND(coredump_note)(l, ns);
409 if (error)
410 return (error);
411
412 /*
413 * Now, for each LWP, write the register info and any other
414 * per-LWP notes.
415 * Lock in case this is a gcore requested dump.
416 */
417 mutex_enter(p->p_lock);
418 LIST_FOREACH(l0, &p->p_lwps, l_sibling) {
419 if (l0 == l) /* we've taken care of this thread */
420 continue;
421 error = ELFNAMEEND(coredump_note)(l0, ns);
422 if (error)
423 break;
424 }
425 mutex_exit(p->p_lock);
426
427 return error;
428 }
429
430 static int
431 ELFNAMEEND(coredump_note)(struct lwp *l, struct note_state *ns)
432 {
433 int error;
434 char name[64];
435 elf_reg intreg;
436 #ifdef PT_GETFPREGS
437 elf_fpreg freg;
438 size_t freglen;
439 #endif
440
441 snprintf(name, sizeof(name), "%s@%d",
442 ELF_NOTE_NETBSD_CORE_NAME, l->l_lid);
443
444 error = elf_process_read_regs(l, &intreg);
445 if (error)
446 return (error);
447
448 ELFNAMEEND(coredump_savenote)(ns, PT_GETREGS, name, &intreg,
449 sizeof(intreg));
450
451 #ifdef PT_GETFPREGS
452 freglen = sizeof(freg);
453 error = elf_process_read_fpregs(l, &freg, &freglen);
454 if (error)
455 return (error);
456
457 ELFNAMEEND(coredump_savenote)(ns, PT_GETFPREGS, name, &freg, freglen);
458 #endif
459 /* XXX Add hook for machdep per-LWP notes. */
460 return (0);
461 }
462
463 static void
464 save_note_bytes(struct note_state *ns, const void *data, size_t len)
465 {
466 struct note_buf *nb = ns->ns_last;
467 size_t copylen;
468 unsigned char *wp;
469
470 /*
471 * Just copy the data into a buffer list.
472 * All but the last buffer is full.
473 */
474 for (;;) {
475 copylen = min(len, sizeof nb->nb_data - ns->ns_offset);
476 wp = nb->nb_data + ns->ns_offset;
477 memcpy(wp, data, copylen);
478 if (copylen == len)
479 break;
480 nb->nb_next = kmem_alloc(sizeof *nb->nb_next, KM_SLEEP);
481 nb = nb->nb_next;
482 ns->ns_last = nb;
483 ns->ns_count++;
484 ns->ns_offset = 0;
485 len -= copylen;
486 data = (const unsigned char *)data + copylen;
487 }
488
489 while (copylen & (ELFROUNDSIZE - 1))
490 wp[copylen++] = 0;
491
492 ns->ns_offset += copylen;
493 }
494
495 void
496 ELFNAMEEND(coredump_savenote)(struct note_state *ns, unsigned int type,
497 const char *name, void *data, size_t data_len)
498 {
499 Elf_Nhdr nhdr;
500
501 nhdr.n_namesz = strlen(name) + 1;
502 nhdr.n_descsz = data_len;
503 nhdr.n_type = type;
504
505 save_note_bytes(ns, &nhdr, sizeof (nhdr));
506 save_note_bytes(ns, name, nhdr.n_namesz);
507 save_note_bytes(ns, data, data_len);
508 }
509
510 #else /* COREDUMP */
511
512 int
513 ELFNAMEEND(coredump)(struct lwp *l, void *cookie)
514 {
515
516 return ENOSYS;
517 }
518
519 #endif /* COREDUMP */
520