xref: /netbsd-src/sys/kern/core_elf32.c (revision d48f14661dda8638fee055ba15d35bdfb29b9fa8)
1 /*	$NetBSD: core_elf32.c,v 1.25 2006/05/14 21:15:11 elad 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 1.25 2006/05/14 21:15:11 elad Exp $");
44 
45 /* If not included by core_elf64.c, ELFSIZE won't be defined. */
46 #ifndef ELFSIZE
47 #define	ELFSIZE		32
48 #endif
49 
50 #include <sys/param.h>
51 #include <sys/systm.h>
52 #include <sys/proc.h>
53 #include <sys/vnode.h>
54 #include <sys/exec.h>
55 #include <sys/exec_elf.h>
56 #include <sys/ptrace.h>
57 #include <sys/malloc.h>
58 #include <sys/kauth.h>
59 
60 #include <machine/reg.h>
61 
62 #include <uvm/uvm_extern.h>
63 
64 struct countsegs_state {
65 	int	npsections;
66 };
67 
68 static int	ELFNAMEEND(coredump_countsegs)(struct proc *, void *,
69 		    struct uvm_coredump_state *);
70 
71 struct writesegs_state {
72 	Elf_Phdr *psections;
73 	off_t	secoff;
74 };
75 
76 static int	ELFNAMEEND(coredump_writeseghdrs)(struct proc *, void *,
77 		    struct uvm_coredump_state *);
78 
79 static int	ELFNAMEEND(coredump_notes)(struct proc *, struct lwp *, void *,
80 		    size_t *);
81 static int	ELFNAMEEND(coredump_note)(struct proc *, struct lwp *, void *,
82 		    size_t *);
83 
84 #define	ELFROUNDSIZE	4	/* XXX Should it be sizeof(Elf_Word)? */
85 #define	elfround(x)	roundup((x), ELFROUNDSIZE)
86 
87 #define elf_process_read_regs	CONCAT(process_read_regs, ELFSIZE)
88 #define elf_process_read_fpregs	CONCAT(process_read_fpregs, ELFSIZE)
89 #define elf_reg			CONCAT(process_reg, ELFSIZE)
90 #define elf_fpreg		CONCAT(process_fpreg, ELFSIZE)
91 
92 int
93 ELFNAMEEND(coredump)(struct lwp *l, void *cookie)
94 {
95 	struct proc *p;
96 	Elf_Ehdr ehdr;
97 	Elf_Phdr phdr, *psections;
98 	struct countsegs_state cs;
99 	struct writesegs_state ws;
100 	off_t notestart, secstart, offset;
101 	size_t notesize;
102 	int error, i;
103 
104 	psections = NULL;
105 	p = l->l_proc;
106 	/*
107 	 * We have to make a total of 3 passes across the map:
108 	 *
109 	 *	1. Count the number of map entries (the number of
110 	 *	   PT_LOAD sections).
111 	 *
112 	 *	2. Write the P-section headers.
113 	 *
114 	 *	3. Write the P-sections.
115 	 */
116 
117 	/* Pass 1: count the entries. */
118 	cs.npsections = 0;
119 	error = uvm_coredump_walkmap(p, NULL,
120 	    ELFNAMEEND(coredump_countsegs), &cs);
121 	if (error)
122 		goto out;
123 
124 	/* Count the PT_NOTE section. */
125 	cs.npsections++;
126 
127 	/* Get the size of the notes. */
128 	error = ELFNAMEEND(coredump_notes)(p, l, NULL, &notesize);
129 	if (error)
130 		goto out;
131 
132 	memset(&ehdr.e_ident[EI_PAD], 0, sizeof(ehdr.e_ident) - EI_PAD);
133 	memcpy(ehdr.e_ident, ELFMAG, SELFMAG);
134 #if ELFSIZE == 32
135 	ehdr.e_ident[EI_CLASS] = ELFCLASS32;
136 #elif ELFSIZE == 64
137 	ehdr.e_ident[EI_CLASS] = ELFCLASS64;
138 #endif
139 	ehdr.e_ident[EI_DATA] = ELFDEFNNAME(MACHDEP_ENDIANNESS);
140 	ehdr.e_ident[EI_VERSION] = EV_CURRENT;
141 	/* XXX Should be the OSABI/ABI version of the executable. */
142 	ehdr.e_ident[EI_OSABI] = ELFOSABI_SYSV;
143 	ehdr.e_ident[EI_ABIVERSION] = 0;
144 
145 	ehdr.e_type = ET_CORE;
146 	/* XXX This should be the e_machine of the executable. */
147 	ehdr.e_machine = ELFDEFNNAME(MACHDEP_ID);
148 	ehdr.e_version = EV_CURRENT;
149 	ehdr.e_entry = 0;
150 	ehdr.e_phoff = sizeof(ehdr);
151 	ehdr.e_shoff = 0;
152 	ehdr.e_flags = 0;
153 	ehdr.e_ehsize = sizeof(ehdr);
154 	ehdr.e_phentsize = sizeof(Elf_Phdr);
155 	ehdr.e_phnum = cs.npsections;
156 	ehdr.e_shentsize = 0;
157 	ehdr.e_shnum = 0;
158 	ehdr.e_shstrndx = 0;
159 
160 	/* Write out the ELF header. */
161 	error = coredump_write(cookie, UIO_SYSSPACE, &ehdr, sizeof(ehdr));
162 	if (error)
163 		goto out;
164 
165 	offset = sizeof(ehdr);
166 
167 	notestart = offset + sizeof(phdr) * cs.npsections;
168 	secstart = notestart + notesize;
169 
170 	psections = malloc(cs.npsections * sizeof(Elf_Phdr),
171 	    M_TEMP, M_WAITOK|M_ZERO);
172 
173 	/* Pass 2: now write the P-section headers. */
174 	ws.secoff = secstart;
175 	ws.psections = psections;
176 	error = uvm_coredump_walkmap(p, cookie,
177 	    ELFNAMEEND(coredump_writeseghdrs), &ws);
178 	if (error)
179 		goto out;
180 
181 	/* Write out the PT_NOTE header. */
182 	ws.psections->p_type = PT_NOTE;
183 	ws.psections->p_offset = notestart;
184 	ws.psections->p_vaddr = 0;
185 	ws.psections->p_paddr = 0;
186 	ws.psections->p_filesz = notesize;
187 	ws.psections->p_memsz = 0;
188 	ws.psections->p_flags = PF_R;
189 	ws.psections->p_align = ELFROUNDSIZE;
190 
191 	error = coredump_write(cookie, UIO_SYSSPACE, psections,
192 	    cs.npsections * sizeof(Elf_Phdr));
193 	if (error)
194 		goto out;
195 
196 #ifdef DIAGNOSTIC
197 	offset += cs.npsections * sizeof(Elf_Phdr);
198 	if (offset != notestart)
199 		panic("coredump: offset %lld != notestart %lld",
200 		    (long long) offset, (long long) notestart);
201 #endif
202 
203 	/* Write out the notes. */
204 	error = ELFNAMEEND(coredump_notes)(p, l, cookie, &notesize);
205 	if (error)
206 		goto out;
207 
208 #ifdef DIAGNOSTIC
209 	offset += notesize;
210 	if (offset != secstart)
211 		panic("coredump: offset %lld != secstart %lld",
212 		    (long long) offset, (long long) secstart);
213 #endif
214 
215 	/* Pass 3: finally, write the sections themselves. */
216 	for (i = 0; i < cs.npsections - 1; i++) {
217 		if (psections[i].p_filesz == 0)
218 			continue;
219 
220 #ifdef DIAGNOSTIC
221 		if (offset != psections[i].p_offset)
222 			panic("coredump: offset %lld != p_offset[%d] %lld",
223 			    (long long) offset, i,
224 			    (long long) psections[i].p_filesz);
225 #endif
226 
227 		error = coredump_write(cookie, UIO_USERSPACE,
228 		    (void *)(vaddr_t)psections[i].p_vaddr,
229 		    psections[i].p_filesz);
230 		if (error)
231 			goto out;
232 
233 #ifdef DIAGNOSTIC
234 		offset += psections[i].p_filesz;
235 #endif
236 	}
237 
238   out:
239 	if (psections)
240 		free(psections, M_TEMP);
241 	return (error);
242 }
243 
244 static int
245 ELFNAMEEND(coredump_countsegs)(struct proc *p, void *iocookie,
246     struct uvm_coredump_state *us)
247 {
248 	struct countsegs_state *cs = us->cookie;
249 
250 	cs->npsections++;
251 	return (0);
252 }
253 
254 static int
255 ELFNAMEEND(coredump_writeseghdrs)(struct proc *p, void *iocookie,
256     struct uvm_coredump_state *us)
257 {
258 	struct writesegs_state *ws = us->cookie;
259 	Elf_Phdr phdr;
260 	vsize_t size, realsize;
261 	vaddr_t end;
262 	int error;
263 
264 	size = us->end - us->start;
265 	realsize = us->realend - us->start;
266 	end = us->realend;
267 
268 	while (realsize > 0) {
269 		long buf[1024 / sizeof(long)];
270 		size_t slen = realsize > sizeof(buf) ? sizeof(buf) : realsize;
271 		const long *ep;
272 		int i;
273 
274 		end -= slen;
275 		if ((error = copyin_proc(p, (void *)end, buf, slen)) != 0)
276 			return error;
277 
278 		ep = (const long *) &buf[slen / sizeof(buf[0])];
279 		for (i = 0, ep--; buf <= ep; ep--, i++) {
280 			if (*ep)
281 				break;
282 		}
283 		realsize -= i * sizeof(buf[0]);
284 		if (i * sizeof(buf[0]) < slen)
285 			break;
286 	}
287 
288 	phdr.p_type = PT_LOAD;
289 	phdr.p_offset = ws->secoff;
290 	phdr.p_vaddr = us->start;
291 	phdr.p_paddr = 0;
292 	phdr.p_filesz = realsize;
293 	phdr.p_memsz = size;
294 	phdr.p_flags = 0;
295 	if (us->prot & VM_PROT_READ)
296 		phdr.p_flags |= PF_R;
297 	if (us->prot & VM_PROT_WRITE)
298 		phdr.p_flags |= PF_W;
299 	if (us->prot & VM_PROT_EXECUTE)
300 		phdr.p_flags |= PF_X;
301 	phdr.p_align = PAGE_SIZE;
302 
303 	ws->secoff += phdr.p_filesz;
304 	*ws->psections++ = phdr;
305 
306 	return (0);
307 }
308 
309 static int
310 ELFNAMEEND(coredump_notes)(struct proc *p, struct lwp *l,
311     void *iocookie, size_t *sizep)
312 {
313 	struct netbsd_elfcore_procinfo cpi;
314 	Elf_Nhdr nhdr;
315 	size_t size, notesize;
316 	int error;
317 	struct lwp *l0;
318 
319 	size = 0;
320 
321 	/* First, write an elfcore_procinfo. */
322 	notesize = sizeof(nhdr) + elfround(sizeof(ELF_NOTE_NETBSD_CORE_NAME)) +
323 	    elfround(sizeof(cpi));
324 	if (iocookie) {
325 		cpi.cpi_version = NETBSD_ELFCORE_PROCINFO_VERSION;
326 		cpi.cpi_cpisize = sizeof(cpi);
327 		cpi.cpi_signo = p->p_sigctx.ps_signo;
328 		cpi.cpi_sigcode = p->p_sigctx.ps_code;
329 		cpi.cpi_siglwp = p->p_sigctx.ps_lwp;
330 
331 		memcpy(&cpi.cpi_sigpend, &p->p_sigctx.ps_siglist,
332 		    sizeof(cpi.cpi_sigpend));
333 		memcpy(&cpi.cpi_sigmask, &p->p_sigctx.ps_sigmask,
334 		    sizeof(cpi.cpi_sigmask));
335 		memcpy(&cpi.cpi_sigignore, &p->p_sigctx.ps_sigignore,
336 		    sizeof(cpi.cpi_sigignore));
337 		memcpy(&cpi.cpi_sigcatch, &p->p_sigctx.ps_sigcatch,
338 		    sizeof(cpi.cpi_sigcatch));
339 
340 		cpi.cpi_pid = p->p_pid;
341 		cpi.cpi_ppid = p->p_pptr->p_pid;
342 		cpi.cpi_pgrp = p->p_pgid;
343 		cpi.cpi_sid = p->p_session->s_sid;
344 
345 		cpi.cpi_ruid = kauth_cred_getuid(p->p_cred);
346 		cpi.cpi_euid = kauth_cred_geteuid(p->p_cred);
347 		cpi.cpi_svuid = kauth_cred_getsvuid(p->p_cred);
348 
349 		cpi.cpi_rgid = kauth_cred_getgid(p->p_cred);
350 		cpi.cpi_egid = kauth_cred_getegid(p->p_cred);
351 		cpi.cpi_svgid = kauth_cred_getsvgid(p->p_cred);
352 
353 		cpi.cpi_nlwps = p->p_nlwps;
354 		(void)strncpy(cpi.cpi_name, p->p_comm, sizeof(cpi.cpi_name));
355 		cpi.cpi_name[sizeof(cpi.cpi_name) - 1] = '\0';
356 
357 		nhdr.n_namesz = sizeof(ELF_NOTE_NETBSD_CORE_NAME);
358 		nhdr.n_descsz = sizeof(cpi);
359 		nhdr.n_type = ELF_NOTE_NETBSD_CORE_PROCINFO;
360 
361 		error = ELFNAMEEND(coredump_writenote)(p, iocookie, &nhdr,
362 		    ELF_NOTE_NETBSD_CORE_NAME "\0\0\0", &cpi);
363 		if (error)
364 			return (error);
365 	}
366 
367 	size += notesize;
368 
369 	/* XXX Add hook for machdep per-proc notes. */
370 
371 	/*
372 	 * Now write the register info for the thread that caused the
373 	 * coredump.
374 	 */
375 	error = ELFNAMEEND(coredump_note)(p, l, iocookie, &notesize);
376 	if (error)
377 		return (error);
378 	size += notesize;
379 
380 	/*
381 	 * Now, for each LWP, write the register info and any other
382 	 * per-LWP notes.
383 	 */
384 	LIST_FOREACH(l0, &p->p_lwps, l_sibling) {
385 		if (l0 == l)		/* we've taken care of this thread */
386 			continue;
387 		error = ELFNAMEEND(coredump_note)(p, l0, iocookie, &notesize);
388 		if (error)
389 			return (error);
390 		size += notesize;
391 	}
392 
393 	*sizep = size;
394 	return (0);
395 }
396 
397 static int
398 ELFNAMEEND(coredump_note)(struct proc *p, struct lwp *l, void *iocookie,
399     size_t *sizep)
400 {
401 	Elf_Nhdr nhdr;
402 	int size, notesize, error;
403 	int namesize;
404 	char name[64+ELFROUNDSIZE];
405 	elf_reg intreg;
406 #ifdef PT_GETFPREGS
407 	elf_fpreg freg;
408 #endif
409 
410 	size = 0;
411 
412 	snprintf(name, sizeof(name)-ELFROUNDSIZE, "%s@%d",
413 	    ELF_NOTE_NETBSD_CORE_NAME, l->l_lid);
414 	namesize = strlen(name) + 1;
415 	memset(name + namesize, 0, elfround(namesize) - namesize);
416 
417 	notesize = sizeof(nhdr) + elfround(namesize) + elfround(sizeof(intreg));
418 	if (iocookie) {
419 		PHOLD(l);
420 		error = elf_process_read_regs(l, &intreg);
421 		PRELE(l);
422 		if (error)
423 			return (error);
424 
425 		nhdr.n_namesz = namesize;
426 		nhdr.n_descsz = sizeof(intreg);
427 		nhdr.n_type = PT_GETREGS;
428 
429 		error = ELFNAMEEND(coredump_writenote)(p, iocookie, &nhdr,
430 		    name, &intreg);
431 		if (error)
432 			return (error);
433 
434 	}
435 	size += notesize;
436 
437 #ifdef PT_GETFPREGS
438 	notesize = sizeof(nhdr) + elfround(namesize) + elfround(sizeof(freg));
439 	if (iocookie) {
440 		PHOLD(l);
441 		error = elf_process_read_fpregs(l, &freg);
442 		PRELE(l);
443 		if (error)
444 			return (error);
445 
446 		nhdr.n_namesz = namesize;
447 		nhdr.n_descsz = sizeof(freg);
448 		nhdr.n_type = PT_GETFPREGS;
449 
450 		error = ELFNAMEEND(coredump_writenote)(p, iocookie, &nhdr,
451 		    name, &freg);
452 		if (error)
453 			return (error);
454 	}
455 	size += notesize;
456 #endif
457 	*sizep = size;
458 	/* XXX Add hook for machdep per-LWP notes. */
459 	return (0);
460 }
461 
462 int
463 ELFNAMEEND(coredump_writenote)(struct proc *p, void *cookie, Elf_Nhdr *nhdr,
464     const char *name, void *data)
465 {
466 	int error;
467 
468 	error = coredump_write(cookie, UIO_SYSSPACE, nhdr, sizeof(*nhdr));
469 	if (error)
470 		return error;
471 
472 	error = coredump_write(cookie, UIO_SYSSPACE, name,
473 	    elfround(nhdr->n_namesz));
474 	if (error)
475 		return error;
476 
477 	return coredump_write(cookie, UIO_SYSSPACE, data, nhdr->n_descsz);
478 }
479