xref: /netbsd-src/sys/kern/core_elf32.c (revision 6dffe8d42bd46273f674d7ab834e7be9b1af990e)
1 /*	$NetBSD: core_elf32.c,v 1.33 2008/11/19 18:36:06 ad 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 1.33 2008/11/19 18:36:06 ad 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 #define elf_process_read_fpregs	CONCAT(process_read_fpregs, ELFSIZE)
94 #define elf_reg			CONCAT(process_reg, ELFSIZE)
95 #define elf_fpreg		CONCAT(process_fpreg, ELFSIZE)
96 
97 int
98 ELFNAMEEND(coredump)(struct lwp *l, void *cookie)
99 {
100 	struct proc *p;
101 	Elf_Ehdr ehdr;
102 	Elf_Phdr phdr, *psections;
103 	struct countsegs_state cs;
104 	struct writesegs_state ws;
105 	off_t notestart, secstart, offset;
106 	size_t notesize;
107 	int error, i;
108 
109 	psections = NULL;
110 	p = l->l_proc;
111 	/*
112 	 * We have to make a total of 3 passes across the map:
113 	 *
114 	 *	1. Count the number of map entries (the number of
115 	 *	   PT_LOAD sections).
116 	 *
117 	 *	2. Write the P-section headers.
118 	 *
119 	 *	3. Write the P-sections.
120 	 */
121 
122 	/* Pass 1: count the entries. */
123 	cs.npsections = 0;
124 	error = uvm_coredump_walkmap(p, NULL,
125 	    ELFNAMEEND(coredump_countsegs), &cs);
126 	if (error)
127 		goto out;
128 
129 	/* Count the PT_NOTE section. */
130 	cs.npsections++;
131 
132 	/* Get the size of the notes. */
133 	error = ELFNAMEEND(coredump_notes)(p, l, NULL, &notesize);
134 	if (error)
135 		goto out;
136 
137 	memset(&ehdr.e_ident[EI_PAD], 0, sizeof(ehdr.e_ident) - EI_PAD);
138 	memcpy(ehdr.e_ident, ELFMAG, SELFMAG);
139 #if ELFSIZE == 32
140 	ehdr.e_ident[EI_CLASS] = ELFCLASS32;
141 #elif ELFSIZE == 64
142 	ehdr.e_ident[EI_CLASS] = ELFCLASS64;
143 #endif
144 	ehdr.e_ident[EI_DATA] = ELFDEFNNAME(MACHDEP_ENDIANNESS);
145 	ehdr.e_ident[EI_VERSION] = EV_CURRENT;
146 	/* XXX Should be the OSABI/ABI version of the executable. */
147 	ehdr.e_ident[EI_OSABI] = ELFOSABI_SYSV;
148 	ehdr.e_ident[EI_ABIVERSION] = 0;
149 
150 	ehdr.e_type = ET_CORE;
151 	/* XXX This should be the e_machine of the executable. */
152 	ehdr.e_machine = ELFDEFNNAME(MACHDEP_ID);
153 	ehdr.e_version = EV_CURRENT;
154 	ehdr.e_entry = 0;
155 	ehdr.e_phoff = sizeof(ehdr);
156 	ehdr.e_shoff = 0;
157 	ehdr.e_flags = 0;
158 	ehdr.e_ehsize = sizeof(ehdr);
159 	ehdr.e_phentsize = sizeof(Elf_Phdr);
160 	ehdr.e_phnum = cs.npsections;
161 	ehdr.e_shentsize = 0;
162 	ehdr.e_shnum = 0;
163 	ehdr.e_shstrndx = 0;
164 
165 	/* Write out the ELF header. */
166 	error = coredump_write(cookie, UIO_SYSSPACE, &ehdr, sizeof(ehdr));
167 	if (error)
168 		goto out;
169 
170 	offset = sizeof(ehdr);
171 
172 	notestart = offset + sizeof(phdr) * cs.npsections;
173 	secstart = notestart + notesize;
174 
175 	psections = malloc(cs.npsections * sizeof(Elf_Phdr),
176 	    M_TEMP, M_WAITOK|M_ZERO);
177 
178 	/* Pass 2: now write the P-section headers. */
179 	ws.secoff = secstart;
180 	ws.psections = psections;
181 	error = uvm_coredump_walkmap(p, cookie,
182 	    ELFNAMEEND(coredump_writeseghdrs), &ws);
183 	if (error)
184 		goto out;
185 
186 	/* Write out the PT_NOTE header. */
187 	ws.psections->p_type = PT_NOTE;
188 	ws.psections->p_offset = notestart;
189 	ws.psections->p_vaddr = 0;
190 	ws.psections->p_paddr = 0;
191 	ws.psections->p_filesz = notesize;
192 	ws.psections->p_memsz = 0;
193 	ws.psections->p_flags = PF_R;
194 	ws.psections->p_align = ELFROUNDSIZE;
195 
196 	error = coredump_write(cookie, UIO_SYSSPACE, psections,
197 	    cs.npsections * sizeof(Elf_Phdr));
198 	if (error)
199 		goto out;
200 
201 #ifdef DIAGNOSTIC
202 	offset += cs.npsections * sizeof(Elf_Phdr);
203 	if (offset != notestart)
204 		panic("coredump: offset %lld != notestart %lld",
205 		    (long long) offset, (long long) notestart);
206 #endif
207 
208 	/* Write out the notes. */
209 	error = ELFNAMEEND(coredump_notes)(p, l, cookie, &notesize);
210 	if (error)
211 		goto out;
212 
213 #ifdef DIAGNOSTIC
214 	offset += notesize;
215 	if (offset != secstart)
216 		panic("coredump: offset %lld != secstart %lld",
217 		    (long long) offset, (long long) secstart);
218 #endif
219 
220 	/* Pass 3: finally, write the sections themselves. */
221 	for (i = 0; i < cs.npsections - 1; i++) {
222 		if (psections[i].p_filesz == 0)
223 			continue;
224 
225 #ifdef DIAGNOSTIC
226 		if (offset != psections[i].p_offset)
227 			panic("coredump: offset %lld != p_offset[%d] %lld",
228 			    (long long) offset, i,
229 			    (long long) psections[i].p_filesz);
230 #endif
231 
232 		error = coredump_write(cookie, UIO_USERSPACE,
233 		    (void *)(vaddr_t)psections[i].p_vaddr,
234 		    psections[i].p_filesz);
235 		if (error)
236 			goto out;
237 
238 #ifdef DIAGNOSTIC
239 		offset += psections[i].p_filesz;
240 #endif
241 	}
242 
243   out:
244 	if (psections)
245 		free(psections, M_TEMP);
246 	return (error);
247 }
248 
249 static int
250 ELFNAMEEND(coredump_countsegs)(struct proc *p, void *iocookie,
251     struct uvm_coredump_state *us)
252 {
253 	struct countsegs_state *cs = us->cookie;
254 
255 	cs->npsections++;
256 	return (0);
257 }
258 
259 static int
260 ELFNAMEEND(coredump_writeseghdrs)(struct proc *p, void *iocookie,
261     struct uvm_coredump_state *us)
262 {
263 	struct writesegs_state *ws = us->cookie;
264 	Elf_Phdr phdr;
265 	vsize_t size, realsize;
266 	vaddr_t end;
267 	int error;
268 
269 	size = us->end - us->start;
270 	realsize = us->realend - us->start;
271 	end = us->realend;
272 
273 	while (realsize > 0) {
274 		long buf[1024 / sizeof(long)];
275 		size_t slen = realsize > sizeof(buf) ? sizeof(buf) : realsize;
276 		const long *ep;
277 		int i;
278 
279 		end -= slen;
280 		if ((error = copyin_proc(p, (void *)end, buf, slen)) != 0)
281 			return error;
282 
283 		ep = (const long *) &buf[slen / sizeof(buf[0])];
284 		for (i = 0, ep--; buf <= ep; ep--, i++) {
285 			if (*ep)
286 				break;
287 		}
288 		realsize -= i * sizeof(buf[0]);
289 		if (i * sizeof(buf[0]) < slen)
290 			break;
291 	}
292 
293 	phdr.p_type = PT_LOAD;
294 	phdr.p_offset = ws->secoff;
295 	phdr.p_vaddr = us->start;
296 	phdr.p_paddr = 0;
297 	phdr.p_filesz = realsize;
298 	phdr.p_memsz = size;
299 	phdr.p_flags = 0;
300 	if (us->prot & VM_PROT_READ)
301 		phdr.p_flags |= PF_R;
302 	if (us->prot & VM_PROT_WRITE)
303 		phdr.p_flags |= PF_W;
304 	if (us->prot & VM_PROT_EXECUTE)
305 		phdr.p_flags |= PF_X;
306 	phdr.p_align = PAGE_SIZE;
307 
308 	ws->secoff += phdr.p_filesz;
309 	*ws->psections++ = phdr;
310 
311 	return (0);
312 }
313 
314 static int
315 ELFNAMEEND(coredump_notes)(struct proc *p, struct lwp *l,
316     void *iocookie, size_t *sizep)
317 {
318 	struct netbsd_elfcore_procinfo cpi;
319 	Elf_Nhdr nhdr;
320 	size_t size, notesize;
321 	int error;
322 	struct lwp *l0;
323 	sigset_t ss1, ss2;
324 
325 	size = 0;
326 
327 	/* First, write an elfcore_procinfo. */
328 	notesize = sizeof(nhdr) + elfround(sizeof(ELF_NOTE_NETBSD_CORE_NAME)) +
329 	    elfround(sizeof(cpi));
330 	if (iocookie) {
331 		cpi.cpi_version = NETBSD_ELFCORE_PROCINFO_VERSION;
332 		cpi.cpi_cpisize = sizeof(cpi);
333 		cpi.cpi_signo = p->p_sigctx.ps_signo;
334 		cpi.cpi_sigcode = p->p_sigctx.ps_code;
335 		cpi.cpi_siglwp = p->p_sigctx.ps_lwp;
336 
337 		/*
338 		 * XXX This should be per-LWP.
339 		 */
340 		ss1 = p->p_sigpend.sp_set;
341 		sigemptyset(&ss2);
342 		LIST_FOREACH(l0, &p->p_lwps, l_sibling) {
343 			sigplusset(&l0->l_sigpend.sp_set, &ss1);
344 			sigplusset(&l0->l_sigmask, &ss2);
345 		}
346 		memcpy(&cpi.cpi_sigpend, &ss1, sizeof(cpi.cpi_sigpend));
347 		memcpy(&cpi.cpi_sigmask, &ss2, sizeof(cpi.cpi_sigmask));
348 		memcpy(&cpi.cpi_sigignore, &p->p_sigctx.ps_sigignore,
349 		    sizeof(cpi.cpi_sigignore));
350 		memcpy(&cpi.cpi_sigcatch, &p->p_sigctx.ps_sigcatch,
351 		    sizeof(cpi.cpi_sigcatch));
352 
353 		cpi.cpi_pid = p->p_pid;
354 		mutex_enter(proc_lock);
355 		cpi.cpi_ppid = p->p_pptr->p_pid;
356 		cpi.cpi_pgrp = p->p_pgid;
357 		cpi.cpi_sid = p->p_session->s_sid;
358 		mutex_exit(proc_lock);
359 
360 		cpi.cpi_ruid = kauth_cred_getuid(l->l_cred);
361 		cpi.cpi_euid = kauth_cred_geteuid(l->l_cred);
362 		cpi.cpi_svuid = kauth_cred_getsvuid(l->l_cred);
363 
364 		cpi.cpi_rgid = kauth_cred_getgid(l->l_cred);
365 		cpi.cpi_egid = kauth_cred_getegid(l->l_cred);
366 		cpi.cpi_svgid = kauth_cred_getsvgid(l->l_cred);
367 
368 		cpi.cpi_nlwps = p->p_nlwps;
369 		(void)strncpy(cpi.cpi_name, p->p_comm, sizeof(cpi.cpi_name));
370 		cpi.cpi_name[sizeof(cpi.cpi_name) - 1] = '\0';
371 
372 		nhdr.n_namesz = sizeof(ELF_NOTE_NETBSD_CORE_NAME);
373 		nhdr.n_descsz = sizeof(cpi);
374 		nhdr.n_type = ELF_NOTE_NETBSD_CORE_PROCINFO;
375 
376 		error = ELFNAMEEND(coredump_writenote)(p, iocookie, &nhdr,
377 		    ELF_NOTE_NETBSD_CORE_NAME "\0\0\0", &cpi);
378 		if (error)
379 			return (error);
380 	}
381 
382 	size += notesize;
383 
384 	/* XXX Add hook for machdep per-proc notes. */
385 
386 	/*
387 	 * Now write the register info for the thread that caused the
388 	 * coredump.
389 	 */
390 	error = ELFNAMEEND(coredump_note)(p, l, iocookie, &notesize);
391 	if (error)
392 		return (error);
393 	size += notesize;
394 
395 	/*
396 	 * Now, for each LWP, write the register info and any other
397 	 * per-LWP notes.  Since we're dumping core, we don't bother
398 	 * locking.
399 	 */
400 	LIST_FOREACH(l0, &p->p_lwps, l_sibling) {
401 		if (l0 == l)		/* we've taken care of this thread */
402 			continue;
403 		error = ELFNAMEEND(coredump_note)(p, l0, iocookie, &notesize);
404 		if (error)
405 			return (error);
406 		size += notesize;
407 	}
408 
409 	*sizep = size;
410 	return (0);
411 }
412 
413 static int
414 ELFNAMEEND(coredump_note)(struct proc *p, struct lwp *l, void *iocookie,
415     size_t *sizep)
416 {
417 	Elf_Nhdr nhdr;
418 	int size, notesize, error;
419 	int namesize;
420 	char name[64+ELFROUNDSIZE];
421 	elf_reg intreg;
422 #ifdef PT_GETFPREGS
423 	elf_fpreg freg;
424 #endif
425 
426 	size = 0;
427 
428 	snprintf(name, sizeof(name)-ELFROUNDSIZE, "%s@%d",
429 	    ELF_NOTE_NETBSD_CORE_NAME, l->l_lid);
430 	namesize = strlen(name) + 1;
431 	memset(name + namesize, 0, elfround(namesize) - namesize);
432 
433 	notesize = sizeof(nhdr) + elfround(namesize) + elfround(sizeof(intreg));
434 	if (iocookie) {
435 		uvm_lwp_hold(l);
436 		error = elf_process_read_regs(l, &intreg);
437 		uvm_lwp_rele(l);
438 		if (error)
439 			return (error);
440 
441 		nhdr.n_namesz = namesize;
442 		nhdr.n_descsz = sizeof(intreg);
443 		nhdr.n_type = PT_GETREGS;
444 
445 		error = ELFNAMEEND(coredump_writenote)(p, iocookie, &nhdr,
446 		    name, &intreg);
447 		if (error)
448 			return (error);
449 
450 	}
451 	size += notesize;
452 
453 #ifdef PT_GETFPREGS
454 	notesize = sizeof(nhdr) + elfround(namesize) + elfround(sizeof(freg));
455 	if (iocookie) {
456 		uvm_lwp_hold(l);
457 		error = elf_process_read_fpregs(l, &freg);
458 		uvm_lwp_rele(l);
459 		if (error)
460 			return (error);
461 
462 		nhdr.n_namesz = namesize;
463 		nhdr.n_descsz = sizeof(freg);
464 		nhdr.n_type = PT_GETFPREGS;
465 
466 		error = ELFNAMEEND(coredump_writenote)(p, iocookie, &nhdr,
467 		    name, &freg);
468 		if (error)
469 			return (error);
470 	}
471 	size += notesize;
472 #endif
473 	*sizep = size;
474 	/* XXX Add hook for machdep per-LWP notes. */
475 	return (0);
476 }
477 
478 int
479 ELFNAMEEND(coredump_writenote)(struct proc *p, void *cookie, Elf_Nhdr *nhdr,
480     const char *name, void *data)
481 {
482 	int error;
483 
484 	error = coredump_write(cookie, UIO_SYSSPACE, nhdr, sizeof(*nhdr));
485 	if (error)
486 		return error;
487 
488 	error = coredump_write(cookie, UIO_SYSSPACE, name,
489 	    elfround(nhdr->n_namesz));
490 	if (error)
491 		return error;
492 
493 	return coredump_write(cookie, UIO_SYSSPACE, data, nhdr->n_descsz);
494 }
495 
496 #else	/* COREDUMP */
497 
498 int
499 ELFNAMEEND(coredump)(struct lwp *l, void *cookie)
500 {
501 
502 	return ENOSYS;
503 }
504 
505 #endif	/* COREDUMP */
506