xref: /netbsd-src/sys/kern/core_elf32.c (revision b1c86f5f087524e68db12794ee9c3e3da1ab17a0)
1 /*	$NetBSD: core_elf32.c,v 1.35 2009/12/14 00:48:35 matt 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 1.35 2009/12/14 00:48:35 matt 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/malloc.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 countsegs_state {
70 	int	npsections;
71 };
72 
73 static int	ELFNAMEEND(coredump_countsegs)(struct proc *, void *,
74 		    struct uvm_coredump_state *);
75 
76 struct writesegs_state {
77 	Elf_Phdr *psections;
78 	off_t	secoff;
79 };
80 
81 static int	ELFNAMEEND(coredump_writeseghdrs)(struct proc *, void *,
82 		    struct uvm_coredump_state *);
83 
84 static int	ELFNAMEEND(coredump_notes)(struct proc *, struct lwp *, void *,
85 		    size_t *);
86 static int	ELFNAMEEND(coredump_note)(struct proc *, struct lwp *, void *,
87 		    size_t *);
88 
89 #define	ELFROUNDSIZE	4	/* XXX Should it be sizeof(Elf_Word)? */
90 #define	elfround(x)	roundup((x), ELFROUNDSIZE)
91 
92 #define elf_process_read_regs	CONCAT(process_read_regs, ELFSIZE)
93 #ifdef __HAVE_PROCESS_XFPREGS
94 #define elf_process_read_xfpregs CONCAT(process_read_xfpregs, ELFSIZE)
95 #else
96 #define elf_process_read_fpregs	CONCAT(process_read_fpregs, ELFSIZE)
97 #endif
98 #define elf_reg			CONCAT(process_reg, ELFSIZE)
99 #define elf_fpreg		CONCAT(process_fpreg, ELFSIZE)
100 
101 int
102 ELFNAMEEND(coredump)(struct lwp *l, void *cookie)
103 {
104 	struct proc *p;
105 	Elf_Ehdr ehdr;
106 	Elf_Phdr phdr, *psections;
107 	struct countsegs_state cs;
108 	struct writesegs_state ws;
109 	off_t notestart, secstart, offset;
110 	size_t notesize;
111 	int error, i;
112 
113 	psections = NULL;
114 	p = l->l_proc;
115 	/*
116 	 * We have to make a total of 3 passes across the map:
117 	 *
118 	 *	1. Count the number of map entries (the number of
119 	 *	   PT_LOAD sections).
120 	 *
121 	 *	2. Write the P-section headers.
122 	 *
123 	 *	3. Write the P-sections.
124 	 */
125 
126 	/* Pass 1: count the entries. */
127 	cs.npsections = 0;
128 	error = uvm_coredump_walkmap(p, NULL,
129 	    ELFNAMEEND(coredump_countsegs), &cs);
130 	if (error)
131 		goto out;
132 
133 	/* Count the PT_NOTE section. */
134 	cs.npsections++;
135 
136 	/* Get the size of the notes. */
137 	error = ELFNAMEEND(coredump_notes)(p, l, NULL, &notesize);
138 	if (error)
139 		goto out;
140 
141 	memset(&ehdr.e_ident[EI_PAD], 0, sizeof(ehdr.e_ident) - EI_PAD);
142 	memcpy(ehdr.e_ident, ELFMAG, SELFMAG);
143 #if ELFSIZE == 32
144 	ehdr.e_ident[EI_CLASS] = ELFCLASS32;
145 #elif ELFSIZE == 64
146 	ehdr.e_ident[EI_CLASS] = ELFCLASS64;
147 #endif
148 	ehdr.e_ident[EI_DATA] = ELFDEFNNAME(MACHDEP_ENDIANNESS);
149 	ehdr.e_ident[EI_VERSION] = EV_CURRENT;
150 	/* XXX Should be the OSABI/ABI version of the executable. */
151 	ehdr.e_ident[EI_OSABI] = ELFOSABI_SYSV;
152 	ehdr.e_ident[EI_ABIVERSION] = 0;
153 
154 	ehdr.e_type = ET_CORE;
155 	/* XXX This should be the e_machine of the executable. */
156 	ehdr.e_machine = ELFDEFNNAME(MACHDEP_ID);
157 	ehdr.e_version = EV_CURRENT;
158 	ehdr.e_entry = 0;
159 	ehdr.e_phoff = sizeof(ehdr);
160 	ehdr.e_shoff = 0;
161 	ehdr.e_flags = 0;
162 	ehdr.e_ehsize = sizeof(ehdr);
163 	ehdr.e_phentsize = sizeof(Elf_Phdr);
164 	ehdr.e_phnum = cs.npsections;
165 	ehdr.e_shentsize = 0;
166 	ehdr.e_shnum = 0;
167 	ehdr.e_shstrndx = 0;
168 
169 #ifdef ELF_MD_COREDUMP_SETUP
170 	ELF_MD_COREDUMP_SETUP(l, &ehdr);
171 #endif
172 
173 	/* Write out the ELF header. */
174 	error = coredump_write(cookie, UIO_SYSSPACE, &ehdr, sizeof(ehdr));
175 	if (error)
176 		goto out;
177 
178 	offset = sizeof(ehdr);
179 
180 	notestart = offset + sizeof(phdr) * cs.npsections;
181 	secstart = notestart + notesize;
182 
183 	psections = malloc(cs.npsections * sizeof(Elf_Phdr),
184 	    M_TEMP, M_WAITOK|M_ZERO);
185 
186 	/* Pass 2: now write the P-section headers. */
187 	ws.secoff = secstart;
188 	ws.psections = psections;
189 	error = uvm_coredump_walkmap(p, cookie,
190 	    ELFNAMEEND(coredump_writeseghdrs), &ws);
191 	if (error)
192 		goto out;
193 
194 	/* Write out the PT_NOTE header. */
195 	ws.psections->p_type = PT_NOTE;
196 	ws.psections->p_offset = notestart;
197 	ws.psections->p_vaddr = 0;
198 	ws.psections->p_paddr = 0;
199 	ws.psections->p_filesz = notesize;
200 	ws.psections->p_memsz = 0;
201 	ws.psections->p_flags = PF_R;
202 	ws.psections->p_align = ELFROUNDSIZE;
203 
204 	error = coredump_write(cookie, UIO_SYSSPACE, psections,
205 	    cs.npsections * sizeof(Elf_Phdr));
206 	if (error)
207 		goto out;
208 
209 #ifdef DIAGNOSTIC
210 	offset += cs.npsections * sizeof(Elf_Phdr);
211 	if (offset != notestart)
212 		panic("coredump: offset %lld != notestart %lld",
213 		    (long long) offset, (long long) notestart);
214 #endif
215 
216 	/* Write out the notes. */
217 	error = ELFNAMEEND(coredump_notes)(p, l, cookie, &notesize);
218 	if (error)
219 		goto out;
220 
221 #ifdef DIAGNOSTIC
222 	offset += notesize;
223 	if (offset != secstart)
224 		panic("coredump: offset %lld != secstart %lld",
225 		    (long long) offset, (long long) secstart);
226 #endif
227 
228 	/* Pass 3: finally, write the sections themselves. */
229 	for (i = 0; i < cs.npsections - 1; i++) {
230 		if (psections[i].p_filesz == 0)
231 			continue;
232 
233 #ifdef DIAGNOSTIC
234 		if (offset != psections[i].p_offset)
235 			panic("coredump: offset %lld != p_offset[%d] %lld",
236 			    (long long) offset, i,
237 			    (long long) psections[i].p_filesz);
238 #endif
239 
240 		error = coredump_write(cookie, UIO_USERSPACE,
241 		    (void *)(vaddr_t)psections[i].p_vaddr,
242 		    psections[i].p_filesz);
243 		if (error)
244 			goto out;
245 
246 #ifdef DIAGNOSTIC
247 		offset += psections[i].p_filesz;
248 #endif
249 	}
250 
251   out:
252 	if (psections)
253 		free(psections, M_TEMP);
254 	return (error);
255 }
256 
257 static int
258 ELFNAMEEND(coredump_countsegs)(struct proc *p, void *iocookie,
259     struct uvm_coredump_state *us)
260 {
261 	struct countsegs_state *cs = us->cookie;
262 
263 	cs->npsections++;
264 	return (0);
265 }
266 
267 static int
268 ELFNAMEEND(coredump_writeseghdrs)(struct proc *p, void *iocookie,
269     struct uvm_coredump_state *us)
270 {
271 	struct writesegs_state *ws = us->cookie;
272 	Elf_Phdr phdr;
273 	vsize_t size, realsize;
274 	vaddr_t end;
275 	int error;
276 
277 	size = us->end - us->start;
278 	realsize = us->realend - us->start;
279 	end = us->realend;
280 
281 	while (realsize > 0) {
282 		long buf[1024 / sizeof(long)];
283 		size_t slen = realsize > sizeof(buf) ? sizeof(buf) : realsize;
284 		const long *ep;
285 		int i;
286 
287 		end -= slen;
288 		if ((error = copyin_proc(p, (void *)end, buf, slen)) != 0)
289 			return error;
290 
291 		ep = (const long *) &buf[slen / sizeof(buf[0])];
292 		for (i = 0, ep--; buf <= ep; ep--, i++) {
293 			if (*ep)
294 				break;
295 		}
296 		realsize -= i * sizeof(buf[0]);
297 		if (i * sizeof(buf[0]) < slen)
298 			break;
299 	}
300 
301 	phdr.p_type = PT_LOAD;
302 	phdr.p_offset = ws->secoff;
303 	phdr.p_vaddr = us->start;
304 	phdr.p_paddr = 0;
305 	phdr.p_filesz = realsize;
306 	phdr.p_memsz = size;
307 	phdr.p_flags = 0;
308 	if (us->prot & VM_PROT_READ)
309 		phdr.p_flags |= PF_R;
310 	if (us->prot & VM_PROT_WRITE)
311 		phdr.p_flags |= PF_W;
312 	if (us->prot & VM_PROT_EXECUTE)
313 		phdr.p_flags |= PF_X;
314 	phdr.p_align = PAGE_SIZE;
315 
316 	ws->secoff += phdr.p_filesz;
317 	*ws->psections++ = phdr;
318 
319 	return (0);
320 }
321 
322 static int
323 ELFNAMEEND(coredump_notes)(struct proc *p, struct lwp *l,
324     void *iocookie, size_t *sizep)
325 {
326 	struct netbsd_elfcore_procinfo cpi;
327 	Elf_Nhdr nhdr;
328 	size_t size, notesize;
329 	int error;
330 	struct lwp *l0;
331 	sigset_t ss1, ss2;
332 
333 	size = 0;
334 
335 	/* First, write an elfcore_procinfo. */
336 	notesize = sizeof(nhdr) + elfround(sizeof(ELF_NOTE_NETBSD_CORE_NAME)) +
337 	    elfround(sizeof(cpi));
338 	if (iocookie) {
339 		cpi.cpi_version = NETBSD_ELFCORE_PROCINFO_VERSION;
340 		cpi.cpi_cpisize = sizeof(cpi);
341 		cpi.cpi_signo = p->p_sigctx.ps_signo;
342 		cpi.cpi_sigcode = p->p_sigctx.ps_code;
343 		cpi.cpi_siglwp = p->p_sigctx.ps_lwp;
344 
345 		/*
346 		 * XXX This should be per-LWP.
347 		 */
348 		ss1 = p->p_sigpend.sp_set;
349 		sigemptyset(&ss2);
350 		LIST_FOREACH(l0, &p->p_lwps, l_sibling) {
351 			sigplusset(&l0->l_sigpend.sp_set, &ss1);
352 			sigplusset(&l0->l_sigmask, &ss2);
353 		}
354 		memcpy(&cpi.cpi_sigpend, &ss1, sizeof(cpi.cpi_sigpend));
355 		memcpy(&cpi.cpi_sigmask, &ss2, sizeof(cpi.cpi_sigmask));
356 		memcpy(&cpi.cpi_sigignore, &p->p_sigctx.ps_sigignore,
357 		    sizeof(cpi.cpi_sigignore));
358 		memcpy(&cpi.cpi_sigcatch, &p->p_sigctx.ps_sigcatch,
359 		    sizeof(cpi.cpi_sigcatch));
360 
361 		cpi.cpi_pid = p->p_pid;
362 		mutex_enter(proc_lock);
363 		cpi.cpi_ppid = p->p_pptr->p_pid;
364 		cpi.cpi_pgrp = p->p_pgid;
365 		cpi.cpi_sid = p->p_session->s_sid;
366 		mutex_exit(proc_lock);
367 
368 		cpi.cpi_ruid = kauth_cred_getuid(l->l_cred);
369 		cpi.cpi_euid = kauth_cred_geteuid(l->l_cred);
370 		cpi.cpi_svuid = kauth_cred_getsvuid(l->l_cred);
371 
372 		cpi.cpi_rgid = kauth_cred_getgid(l->l_cred);
373 		cpi.cpi_egid = kauth_cred_getegid(l->l_cred);
374 		cpi.cpi_svgid = kauth_cred_getsvgid(l->l_cred);
375 
376 		cpi.cpi_nlwps = p->p_nlwps;
377 		(void)strncpy(cpi.cpi_name, p->p_comm, sizeof(cpi.cpi_name));
378 		cpi.cpi_name[sizeof(cpi.cpi_name) - 1] = '\0';
379 
380 		nhdr.n_namesz = sizeof(ELF_NOTE_NETBSD_CORE_NAME);
381 		nhdr.n_descsz = sizeof(cpi);
382 		nhdr.n_type = ELF_NOTE_NETBSD_CORE_PROCINFO;
383 
384 		error = ELFNAMEEND(coredump_writenote)(p, iocookie, &nhdr,
385 		    ELF_NOTE_NETBSD_CORE_NAME "\0\0\0", &cpi);
386 		if (error)
387 			return (error);
388 	}
389 
390 	size += notesize;
391 
392 	/* XXX Add hook for machdep per-proc notes. */
393 
394 	/*
395 	 * Now write the register info for the thread that caused the
396 	 * coredump.
397 	 */
398 	error = ELFNAMEEND(coredump_note)(p, l, iocookie, &notesize);
399 	if (error)
400 		return (error);
401 	size += notesize;
402 
403 	/*
404 	 * Now, for each LWP, write the register info and any other
405 	 * per-LWP notes.  Since we're dumping core, we don't bother
406 	 * locking.
407 	 */
408 	LIST_FOREACH(l0, &p->p_lwps, l_sibling) {
409 		if (l0 == l)		/* we've taken care of this thread */
410 			continue;
411 		error = ELFNAMEEND(coredump_note)(p, l0, iocookie, &notesize);
412 		if (error)
413 			return (error);
414 		size += notesize;
415 	}
416 
417 	*sizep = size;
418 	return (0);
419 }
420 
421 static int
422 ELFNAMEEND(coredump_note)(struct proc *p, struct lwp *l, void *iocookie,
423     size_t *sizep)
424 {
425 	Elf_Nhdr nhdr;
426 	int size, notesize, error;
427 	int namesize;
428 	char name[64+ELFROUNDSIZE];
429 	elf_reg intreg;
430 #ifdef PT_GETFPREGS
431 	elf_fpreg freg;
432 #endif
433 
434 	size = 0;
435 
436 	snprintf(name, sizeof(name)-ELFROUNDSIZE, "%s@%d",
437 	    ELF_NOTE_NETBSD_CORE_NAME, l->l_lid);
438 	namesize = strlen(name) + 1;
439 	memset(name + namesize, 0, elfround(namesize) - namesize);
440 
441 	notesize = sizeof(nhdr) + elfround(namesize) + elfround(sizeof(intreg));
442 	if (iocookie) {
443 		error = elf_process_read_regs(l, &intreg);
444 		if (error)
445 			return (error);
446 
447 		nhdr.n_namesz = namesize;
448 		nhdr.n_descsz = sizeof(intreg);
449 		nhdr.n_type = PT_GETREGS;
450 
451 		error = ELFNAMEEND(coredump_writenote)(p, iocookie, &nhdr,
452 		    name, &intreg);
453 		if (error)
454 			return (error);
455 
456 	}
457 	size += notesize;
458 
459 #ifdef PT_GETFPREGS
460 	notesize = sizeof(nhdr) + elfround(namesize) + elfround(sizeof(freg));
461 	if (iocookie) {
462 		size_t freglen = sizeof(freg);
463 #ifdef __HAVE_PROCESS_XFPREGS
464 		error = elf_process_read_xfpregs(l, &freg, &freglen);
465 #else
466 		error = elf_process_read_fpregs(l, &freg);
467 #endif
468 		if (error)
469 			return (error);
470 
471 		nhdr.n_namesz = namesize;
472 		nhdr.n_descsz = freglen;
473 		nhdr.n_type = PT_GETFPREGS;
474 
475 		error = ELFNAMEEND(coredump_writenote)(p, iocookie, &nhdr,
476 		    name, &freg);
477 		if (error)
478 			return (error);
479 	}
480 	size += notesize;
481 #endif
482 	*sizep = size;
483 	/* XXX Add hook for machdep per-LWP notes. */
484 	return (0);
485 }
486 
487 int
488 ELFNAMEEND(coredump_writenote)(struct proc *p, void *cookie, Elf_Nhdr *nhdr,
489     const char *name, void *data)
490 {
491 	int error;
492 
493 	error = coredump_write(cookie, UIO_SYSSPACE, nhdr, sizeof(*nhdr));
494 	if (error)
495 		return error;
496 
497 	error = coredump_write(cookie, UIO_SYSSPACE, name,
498 	    elfround(nhdr->n_namesz));
499 	if (error)
500 		return error;
501 
502 	return coredump_write(cookie, UIO_SYSSPACE, data, nhdr->n_descsz);
503 }
504 
505 #else	/* COREDUMP */
506 
507 int
508 ELFNAMEEND(coredump)(struct lwp *l, void *cookie)
509 {
510 
511 	return ENOSYS;
512 }
513 
514 #endif	/* COREDUMP */
515