xref: /illumos-gate/usr/src/uts/common/exec/elf/elf.c (revision bc0adaff12f765cf25f5cc993be869deebd1e62d)
1 /*
2  * CDDL HEADER START
3  *
4  * The contents of this file are subject to the terms of the
5  * Common Development and Distribution License (the "License").
6  * You may not use this file except in compliance with the License.
7  *
8  * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
9  * or http://www.opensolaris.org/os/licensing.
10  * See the License for the specific language governing permissions
11  * and limitations under the License.
12  *
13  * When distributing Covered Code, include this CDDL HEADER in each
14  * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
15  * If applicable, add the following below this CDDL HEADER, with the
16  * fields enclosed by brackets "[]" replaced with your own identifying
17  * information: Portions Copyright [yyyy] [name of copyright owner]
18  *
19  * CDDL HEADER END
20  */
21 
22 /*
23  * Copyright (c) 1989, 2010, Oracle and/or its affiliates. All rights reserved.
24  */
25 
26 /*	Copyright (c) 1984, 1986, 1987, 1988, 1989 AT&T	*/
27 /*	   All Rights Reserved	*/
28 /*
29  * Copyright (c) 2018, Joyent, Inc.
30  */
31 
32 #include <sys/types.h>
33 #include <sys/param.h>
34 #include <sys/thread.h>
35 #include <sys/sysmacros.h>
36 #include <sys/signal.h>
37 #include <sys/cred.h>
38 #include <sys/user.h>
39 #include <sys/errno.h>
40 #include <sys/vnode.h>
41 #include <sys/mman.h>
42 #include <sys/kmem.h>
43 #include <sys/proc.h>
44 #include <sys/pathname.h>
45 #include <sys/policy.h>
46 #include <sys/cmn_err.h>
47 #include <sys/systm.h>
48 #include <sys/elf.h>
49 #include <sys/vmsystm.h>
50 #include <sys/debug.h>
51 #include <sys/auxv.h>
52 #include <sys/exec.h>
53 #include <sys/prsystm.h>
54 #include <vm/as.h>
55 #include <vm/rm.h>
56 #include <vm/seg.h>
57 #include <vm/seg_vn.h>
58 #include <sys/modctl.h>
59 #include <sys/systeminfo.h>
60 #include <sys/vmparam.h>
61 #include <sys/machelf.h>
62 #include <sys/shm_impl.h>
63 #include <sys/archsystm.h>
64 #include <sys/fasttrap.h>
65 #include <sys/brand.h>
66 #include "elf_impl.h"
67 #include <sys/sdt.h>
68 #include <sys/siginfo.h>
69 #include <sys/random.h>
70 
71 #if defined(__x86)
72 #include <sys/comm_page_util.h>
73 #include <sys/fp.h>
74 #endif /* defined(__x86) */
75 
76 
77 extern int at_flags;
78 extern volatile size_t aslr_max_brk_skew;
79 
80 #define	ORIGIN_STR	"ORIGIN"
81 #define	ORIGIN_STR_SIZE	6
82 
83 static int getelfhead(vnode_t *, cred_t *, Ehdr *, int *, int *, int *);
84 static int getelfphdr(vnode_t *, cred_t *, const Ehdr *, int, caddr_t *,
85     ssize_t *);
86 static int getelfshdr(vnode_t *, cred_t *, const Ehdr *, int, int, caddr_t *,
87     ssize_t *, caddr_t *, ssize_t *);
88 static size_t elfsize(Ehdr *, int, caddr_t, uintptr_t *);
89 static int mapelfexec(vnode_t *, Ehdr *, int, caddr_t,
90     Phdr **, Phdr **, Phdr **, Phdr **, Phdr *,
91     caddr_t *, caddr_t *, intptr_t *, intptr_t *, size_t, long *, size_t *);
92 
93 typedef enum {
94 	STR_CTF,
95 	STR_SYMTAB,
96 	STR_DYNSYM,
97 	STR_STRTAB,
98 	STR_DYNSTR,
99 	STR_SHSTRTAB,
100 	STR_NUM
101 } shstrtype_t;
102 
103 static const char *shstrtab_data[] = {
104 	".SUNW_ctf",
105 	".symtab",
106 	".dynsym",
107 	".strtab",
108 	".dynstr",
109 	".shstrtab"
110 };
111 
112 typedef struct shstrtab {
113 	int	sst_ndx[STR_NUM];
114 	int	sst_cur;
115 } shstrtab_t;
116 
117 static void
118 shstrtab_init(shstrtab_t *s)
119 {
120 	bzero(&s->sst_ndx, sizeof (s->sst_ndx));
121 	s->sst_cur = 1;
122 }
123 
124 static int
125 shstrtab_ndx(shstrtab_t *s, shstrtype_t type)
126 {
127 	int ret;
128 
129 	if ((ret = s->sst_ndx[type]) != 0)
130 		return (ret);
131 
132 	ret = s->sst_ndx[type] = s->sst_cur;
133 	s->sst_cur += strlen(shstrtab_data[type]) + 1;
134 
135 	return (ret);
136 }
137 
138 static size_t
139 shstrtab_size(const shstrtab_t *s)
140 {
141 	return (s->sst_cur);
142 }
143 
144 static void
145 shstrtab_dump(const shstrtab_t *s, char *buf)
146 {
147 	int i, ndx;
148 
149 	*buf = '\0';
150 	for (i = 0; i < STR_NUM; i++) {
151 		if ((ndx = s->sst_ndx[i]) != 0)
152 			(void) strcpy(buf + ndx, shstrtab_data[i]);
153 	}
154 }
155 
156 static int
157 dtrace_safe_phdr(Phdr *phdrp, struct uarg *args, uintptr_t base)
158 {
159 	ASSERT(phdrp->p_type == PT_SUNWDTRACE);
160 
161 	/*
162 	 * See the comment in fasttrap.h for information on how to safely
163 	 * update this program header.
164 	 */
165 	if (phdrp->p_memsz < PT_SUNWDTRACE_SIZE ||
166 	    (phdrp->p_flags & (PF_R | PF_W | PF_X)) != (PF_R | PF_W | PF_X))
167 		return (-1);
168 
169 	args->thrptr = phdrp->p_vaddr + base;
170 
171 	return (0);
172 }
173 
174 static int
175 handle_secflag_dt(proc_t *p, uint_t dt, uint_t val)
176 {
177 	uint_t flag;
178 
179 	switch (dt) {
180 	case DT_SUNW_ASLR:
181 		flag = PROC_SEC_ASLR;
182 		break;
183 	default:
184 		return (EINVAL);
185 	}
186 
187 	if (val == 0) {
188 		if (secflag_isset(p->p_secflags.psf_lower, flag))
189 			return (EPERM);
190 		if ((secpolicy_psecflags(CRED(), p, p) != 0) &&
191 		    secflag_isset(p->p_secflags.psf_inherit, flag))
192 			return (EPERM);
193 
194 		secflag_clear(&p->p_secflags.psf_effective, flag);
195 	} else {
196 		if (!secflag_isset(p->p_secflags.psf_upper, flag))
197 			return (EPERM);
198 
199 		if ((secpolicy_psecflags(CRED(), p, p) != 0) &&
200 		    !secflag_isset(p->p_secflags.psf_inherit, flag))
201 			return (EPERM);
202 
203 		secflag_set(&p->p_secflags.psf_effective, flag);
204 	}
205 
206 	return (0);
207 }
208 
209 /*
210  * Map in the executable pointed to by vp. Returns 0 on success.
211  */
212 int
213 mapexec_brand(vnode_t *vp, uarg_t *args, Ehdr *ehdr, Addr *uphdr_vaddr,
214     intptr_t *voffset, caddr_t exec_file, int *interp, caddr_t *bssbase,
215     caddr_t *brkbase, size_t *brksize, uintptr_t *lddatap)
216 {
217 	size_t		len;
218 	struct vattr	vat;
219 	caddr_t		phdrbase = NULL;
220 	ssize_t		phdrsize;
221 	int		nshdrs, shstrndx, nphdrs;
222 	int		error = 0;
223 	Phdr		*uphdr = NULL;
224 	Phdr		*junk = NULL;
225 	Phdr		*dynphdr = NULL;
226 	Phdr		*dtrphdr = NULL;
227 	uintptr_t	lddata;
228 	long		execsz;
229 	intptr_t	minaddr;
230 
231 	if (lddatap != NULL)
232 		*lddatap = NULL;
233 
234 	if (error = execpermissions(vp, &vat, args)) {
235 		uprintf("%s: Cannot execute %s\n", exec_file, args->pathname);
236 		return (error);
237 	}
238 
239 	if ((error = getelfhead(vp, CRED(), ehdr, &nshdrs, &shstrndx,
240 	    &nphdrs)) != 0 ||
241 	    (error = getelfphdr(vp, CRED(), ehdr, nphdrs, &phdrbase,
242 	    &phdrsize)) != 0) {
243 		uprintf("%s: Cannot read %s\n", exec_file, args->pathname);
244 		return (error);
245 	}
246 
247 	if ((len = elfsize(ehdr, nphdrs, phdrbase, &lddata)) == 0) {
248 		uprintf("%s: Nothing to load in %s", exec_file, args->pathname);
249 		kmem_free(phdrbase, phdrsize);
250 		return (ENOEXEC);
251 	}
252 	if (lddatap != NULL)
253 		*lddatap = lddata;
254 
255 	if (error = mapelfexec(vp, ehdr, nphdrs, phdrbase, &uphdr, &dynphdr,
256 	    &junk, &dtrphdr, NULL, bssbase, brkbase, voffset, &minaddr,
257 	    len, &execsz, brksize)) {
258 		uprintf("%s: Cannot map %s\n", exec_file, args->pathname);
259 		kmem_free(phdrbase, phdrsize);
260 		return (error);
261 	}
262 
263 	/*
264 	 * Inform our caller if the executable needs an interpreter.
265 	 */
266 	*interp = (dynphdr == NULL) ? 0 : 1;
267 
268 	/*
269 	 * If this is a statically linked executable, voffset should indicate
270 	 * the address of the executable itself (it normally holds the address
271 	 * of the interpreter).
272 	 */
273 	if (ehdr->e_type == ET_EXEC && *interp == 0)
274 		*voffset = minaddr;
275 
276 	if (uphdr != NULL) {
277 		*uphdr_vaddr = uphdr->p_vaddr;
278 	} else {
279 		*uphdr_vaddr = (Addr)-1;
280 	}
281 
282 	kmem_free(phdrbase, phdrsize);
283 	return (error);
284 }
285 
286 /*ARGSUSED*/
287 int
288 elfexec(vnode_t *vp, execa_t *uap, uarg_t *args, intpdata_t *idatap,
289     int level, long *execsz, int setid, caddr_t exec_file, cred_t *cred,
290     int brand_action)
291 {
292 	caddr_t		phdrbase = NULL;
293 	caddr_t		bssbase = 0;
294 	caddr_t		brkbase = 0;
295 	size_t		brksize = 0;
296 	ssize_t		dlnsize;
297 	aux_entry_t	*aux;
298 	int		error;
299 	ssize_t		resid;
300 	int		fd = -1;
301 	intptr_t	voffset;
302 	Phdr		*intphdr = NULL;
303 	Phdr		*dynamicphdr = NULL;
304 	Phdr		*stphdr = NULL;
305 	Phdr		*uphdr = NULL;
306 	Phdr		*junk = NULL;
307 	size_t		len;
308 	ssize_t		phdrsize;
309 	int		postfixsize = 0;
310 	int		i, hsize;
311 	Phdr		*phdrp;
312 	Phdr		*dataphdrp = NULL;
313 	Phdr		*dtrphdr;
314 	Phdr		*capphdr = NULL;
315 	Cap		*cap = NULL;
316 	ssize_t		capsize;
317 	Dyn		*dyn = NULL;
318 	int		hasu = 0;
319 	int		hasauxv = 0;
320 	int		hasintp = 0;
321 	int		branded = 0;
322 
323 	struct proc *p = ttoproc(curthread);
324 	struct user *up = PTOU(p);
325 	struct bigwad {
326 		Ehdr	ehdr;
327 		aux_entry_t	elfargs[__KERN_NAUXV_IMPL];
328 		char		dl_name[MAXPATHLEN];
329 		char		pathbuf[MAXPATHLEN];
330 		struct vattr	vattr;
331 		struct execenv	exenv;
332 	} *bigwad;	/* kmem_alloc this behemoth so we don't blow stack */
333 	Ehdr		*ehdrp;
334 	int		nshdrs, shstrndx, nphdrs;
335 	char		*dlnp;
336 	char		*pathbufp;
337 	rlim64_t	limit;
338 	rlim64_t	roundlimit;
339 
340 	ASSERT(p->p_model == DATAMODEL_ILP32 || p->p_model == DATAMODEL_LP64);
341 
342 	bigwad = kmem_alloc(sizeof (struct bigwad), KM_SLEEP);
343 	ehdrp = &bigwad->ehdr;
344 	dlnp = bigwad->dl_name;
345 	pathbufp = bigwad->pathbuf;
346 
347 	/*
348 	 * Obtain ELF and program header information.
349 	 */
350 	if ((error = getelfhead(vp, CRED(), ehdrp, &nshdrs, &shstrndx,
351 	    &nphdrs)) != 0 ||
352 	    (error = getelfphdr(vp, CRED(), ehdrp, nphdrs, &phdrbase,
353 	    &phdrsize)) != 0)
354 		goto out;
355 
356 	/*
357 	 * Prevent executing an ELF file that has no entry point.
358 	 */
359 	if (ehdrp->e_entry == 0) {
360 		uprintf("%s: Bad entry point\n", exec_file);
361 		goto bad;
362 	}
363 
364 	/*
365 	 * Put data model that we're exec-ing to into the args passed to
366 	 * exec_args(), so it will know what it is copying to on new stack.
367 	 * Now that we know whether we are exec-ing a 32-bit or 64-bit
368 	 * executable, we can set execsz with the appropriate NCARGS.
369 	 */
370 #ifdef	_LP64
371 	if (ehdrp->e_ident[EI_CLASS] == ELFCLASS32) {
372 		args->to_model = DATAMODEL_ILP32;
373 		*execsz = btopr(SINCR) + btopr(SSIZE) + btopr(NCARGS32-1);
374 	} else {
375 		args->to_model = DATAMODEL_LP64;
376 		args->stk_prot &= ~PROT_EXEC;
377 #if defined(__i386) || defined(__amd64)
378 		args->dat_prot &= ~PROT_EXEC;
379 #endif
380 		*execsz = btopr(SINCR) + btopr(SSIZE) + btopr(NCARGS64-1);
381 	}
382 #else	/* _LP64 */
383 	args->to_model = DATAMODEL_ILP32;
384 	*execsz = btopr(SINCR) + btopr(SSIZE) + btopr(NCARGS-1);
385 #endif	/* _LP64 */
386 
387 	/*
388 	 * We delay invoking the brand callback until we've figured out
389 	 * what kind of elf binary we're trying to run, 32-bit or 64-bit.
390 	 * We do this because now the brand library can just check
391 	 * args->to_model to see if the target is 32-bit or 64-bit without
392 	 * having do duplicate all the code above.
393 	 *
394 	 * The level checks associated with brand handling below are used to
395 	 * prevent a loop since the brand elfexec function typically comes back
396 	 * through this function. We must check <= here since the nested
397 	 * handling in the #! interpreter code will increment the level before
398 	 * calling gexec to run the final elfexec interpreter.
399 	 */
400 	if ((level <= INTP_MAXDEPTH) &&
401 	    (brand_action != EBA_NATIVE) && (PROC_IS_BRANDED(p))) {
402 		error = BROP(p)->b_elfexec(vp, uap, args,
403 		    idatap, level + 1, execsz, setid, exec_file, cred,
404 		    brand_action);
405 		goto out;
406 	}
407 
408 	/*
409 	 * Determine aux size now so that stack can be built
410 	 * in one shot (except actual copyout of aux image),
411 	 * determine any non-default stack protections,
412 	 * and still have this code be machine independent.
413 	 */
414 	hsize = ehdrp->e_phentsize;
415 	phdrp = (Phdr *)phdrbase;
416 	for (i = nphdrs; i > 0; i--) {
417 		switch (phdrp->p_type) {
418 		case PT_INTERP:
419 			hasauxv = hasintp = 1;
420 			break;
421 		case PT_PHDR:
422 			hasu = 1;
423 			break;
424 		case PT_SUNWSTACK:
425 			args->stk_prot = PROT_USER;
426 			if (phdrp->p_flags & PF_R)
427 				args->stk_prot |= PROT_READ;
428 			if (phdrp->p_flags & PF_W)
429 				args->stk_prot |= PROT_WRITE;
430 			if (phdrp->p_flags & PF_X)
431 				args->stk_prot |= PROT_EXEC;
432 			break;
433 		case PT_LOAD:
434 			dataphdrp = phdrp;
435 			break;
436 		case PT_SUNWCAP:
437 			capphdr = phdrp;
438 			break;
439 		case PT_DYNAMIC:
440 			dynamicphdr = phdrp;
441 			break;
442 		}
443 		phdrp = (Phdr *)((caddr_t)phdrp + hsize);
444 	}
445 
446 	if (ehdrp->e_type != ET_EXEC) {
447 		dataphdrp = NULL;
448 		hasauxv = 1;
449 	}
450 
451 	/* Copy BSS permissions to args->dat_prot */
452 	if (dataphdrp != NULL) {
453 		args->dat_prot = PROT_USER;
454 		if (dataphdrp->p_flags & PF_R)
455 			args->dat_prot |= PROT_READ;
456 		if (dataphdrp->p_flags & PF_W)
457 			args->dat_prot |= PROT_WRITE;
458 		if (dataphdrp->p_flags & PF_X)
459 			args->dat_prot |= PROT_EXEC;
460 	}
461 
462 	/*
463 	 * If a auxvector will be required - reserve the space for
464 	 * it now.  This may be increased by exec_args if there are
465 	 * ISA-specific types (included in __KERN_NAUXV_IMPL).
466 	 */
467 	if (hasauxv) {
468 		/*
469 		 * If a AUX vector is being built - the base AUX
470 		 * entries are:
471 		 *
472 		 *	AT_BASE
473 		 *	AT_FLAGS
474 		 *	AT_PAGESZ
475 		 *	AT_SUN_AUXFLAGS
476 		 *	AT_SUN_HWCAP
477 		 *	AT_SUN_HWCAP2
478 		 *	AT_SUN_PLATFORM (added in stk_copyout)
479 		 *	AT_SUN_EXECNAME (added in stk_copyout)
480 		 *	AT_NULL
481 		 *
482 		 * total == 9
483 		 */
484 		if (hasintp && hasu) {
485 			/*
486 			 * Has PT_INTERP & PT_PHDR - the auxvectors that
487 			 * will be built are:
488 			 *
489 			 *	AT_PHDR
490 			 *	AT_PHENT
491 			 *	AT_PHNUM
492 			 *	AT_ENTRY
493 			 *	AT_LDDATA
494 			 *
495 			 * total = 5
496 			 */
497 			args->auxsize = (9 + 5) * sizeof (aux_entry_t);
498 		} else if (hasintp) {
499 			/*
500 			 * Has PT_INTERP but no PT_PHDR
501 			 *
502 			 *	AT_EXECFD
503 			 *	AT_LDDATA
504 			 *
505 			 * total = 2
506 			 */
507 			args->auxsize = (9 + 2) * sizeof (aux_entry_t);
508 		} else {
509 			args->auxsize = 9 * sizeof (aux_entry_t);
510 		}
511 	} else {
512 		args->auxsize = 0;
513 	}
514 
515 	/*
516 	 * If this binary is using an emulator, we need to add an
517 	 * AT_SUN_EMULATOR aux entry.
518 	 */
519 	if (args->emulator != NULL)
520 		args->auxsize += sizeof (aux_entry_t);
521 
522 	/*
523 	 * On supported kernels (x86_64) make room in the auxv for the
524 	 * AT_SUN_COMMPAGE entry.  This will go unpopulated on i86xpv systems
525 	 * which do not provide such functionality.
526 	 *
527 	 * Additionally cover the floating point information AT_SUN_FPSIZE and
528 	 * AT_SUN_FPTYPE.
529 	 */
530 #if defined(__amd64)
531 	args->auxsize += 3 * sizeof (aux_entry_t);
532 #endif /* defined(__amd64) */
533 
534 	if ((brand_action != EBA_NATIVE) && (PROC_IS_BRANDED(p))) {
535 		branded = 1;
536 		/*
537 		 * We will be adding 4 entries to the aux vectors.  One for
538 		 * the the brandname and 3 for the brand specific aux vectors.
539 		 */
540 		args->auxsize += 4 * sizeof (aux_entry_t);
541 	}
542 
543 	/* If the binary has an explicit ASLR flag, it must be honoured */
544 	if ((dynamicphdr != NULL) &&
545 	    (dynamicphdr->p_filesz > 0)) {
546 		Dyn *dp;
547 		off_t i = 0;
548 
549 #define	DYN_STRIDE	100
550 		for (i = 0; i < dynamicphdr->p_filesz;
551 		    i += sizeof (*dyn) * DYN_STRIDE) {
552 			int ndyns = (dynamicphdr->p_filesz - i) / sizeof (*dyn);
553 			size_t dynsize;
554 
555 			ndyns = MIN(DYN_STRIDE, ndyns);
556 			dynsize = ndyns * sizeof (*dyn);
557 
558 			dyn = kmem_alloc(dynsize, KM_SLEEP);
559 
560 			if ((error = vn_rdwr(UIO_READ, vp, (caddr_t)dyn,
561 			    dynsize, (offset_t)(dynamicphdr->p_offset + i),
562 			    UIO_SYSSPACE, 0, (rlim64_t)0,
563 			    CRED(), &resid)) != 0) {
564 				uprintf("%s: cannot read .dynamic section\n",
565 				    exec_file);
566 				goto out;
567 			}
568 
569 			for (dp = dyn; dp < (dyn + ndyns); dp++) {
570 				if (dp->d_tag == DT_SUNW_ASLR) {
571 					if ((error = handle_secflag_dt(p,
572 					    DT_SUNW_ASLR,
573 					    dp->d_un.d_val)) != 0) {
574 						uprintf("%s: error setting "
575 						    "security-flag from "
576 						    "DT_SUNW_ASLR: %d\n",
577 						    exec_file, error);
578 						goto out;
579 					}
580 				}
581 			}
582 
583 			kmem_free(dyn, dynsize);
584 		}
585 	}
586 
587 	/* Hardware/Software capabilities */
588 	if (capphdr != NULL &&
589 	    (capsize = capphdr->p_filesz) > 0 &&
590 	    capsize <= 16 * sizeof (*cap)) {
591 		int ncaps = capsize / sizeof (*cap);
592 		Cap *cp;
593 
594 		cap = kmem_alloc(capsize, KM_SLEEP);
595 		if ((error = vn_rdwr(UIO_READ, vp, (caddr_t)cap,
596 		    capsize, (offset_t)capphdr->p_offset,
597 		    UIO_SYSSPACE, 0, (rlim64_t)0, CRED(), &resid)) != 0) {
598 			uprintf("%s: Cannot read capabilities section\n",
599 			    exec_file);
600 			goto out;
601 		}
602 		for (cp = cap; cp < cap + ncaps; cp++) {
603 			if (cp->c_tag == CA_SUNW_SF_1 &&
604 			    (cp->c_un.c_val & SF1_SUNW_ADDR32)) {
605 				if (args->to_model == DATAMODEL_LP64)
606 					args->addr32 = 1;
607 				break;
608 			}
609 		}
610 	}
611 
612 	aux = bigwad->elfargs;
613 	/*
614 	 * Move args to the user's stack.
615 	 * This can fill in the AT_SUN_PLATFORM and AT_SUN_EXECNAME aux entries.
616 	 */
617 	if ((error = exec_args(uap, args, idatap, (void **)&aux)) != 0) {
618 		if (error == -1) {
619 			error = ENOEXEC;
620 			goto bad;
621 		}
622 		goto out;
623 	}
624 	/* we're single threaded after this point */
625 
626 	/*
627 	 * If this is an ET_DYN executable (shared object),
628 	 * determine its memory size so that mapelfexec() can load it.
629 	 */
630 	if (ehdrp->e_type == ET_DYN)
631 		len = elfsize(ehdrp, nphdrs, phdrbase, NULL);
632 	else
633 		len = 0;
634 
635 	dtrphdr = NULL;
636 
637 	if ((error = mapelfexec(vp, ehdrp, nphdrs, phdrbase, &uphdr, &intphdr,
638 	    &stphdr, &dtrphdr, dataphdrp, &bssbase, &brkbase, &voffset, NULL,
639 	    len, execsz, &brksize)) != 0)
640 		goto bad;
641 
642 	if (uphdr != NULL && intphdr == NULL)
643 		goto bad;
644 
645 	if (dtrphdr != NULL && dtrace_safe_phdr(dtrphdr, args, voffset) != 0) {
646 		uprintf("%s: Bad DTrace phdr in %s\n", exec_file, exec_file);
647 		goto bad;
648 	}
649 
650 	if (intphdr != NULL) {
651 		size_t		len;
652 		uintptr_t	lddata;
653 		char		*p;
654 		struct vnode	*nvp;
655 
656 		dlnsize = intphdr->p_filesz;
657 
658 		if (dlnsize > MAXPATHLEN || dlnsize <= 0)
659 			goto bad;
660 
661 		/*
662 		 * Read in "interpreter" pathname.
663 		 */
664 		if ((error = vn_rdwr(UIO_READ, vp, dlnp, intphdr->p_filesz,
665 		    (offset_t)intphdr->p_offset, UIO_SYSSPACE, 0, (rlim64_t)0,
666 		    CRED(), &resid)) != 0) {
667 			uprintf("%s: Cannot obtain interpreter pathname\n",
668 			    exec_file);
669 			goto bad;
670 		}
671 
672 		if (resid != 0 || dlnp[dlnsize - 1] != '\0')
673 			goto bad;
674 
675 		/*
676 		 * Search for '$ORIGIN' token in interpreter path.
677 		 * If found, expand it.
678 		 */
679 		for (p = dlnp; p = strchr(p, '$'); ) {
680 			uint_t	len, curlen;
681 			char	*_ptr;
682 
683 			if (strncmp(++p, ORIGIN_STR, ORIGIN_STR_SIZE))
684 				continue;
685 
686 			/*
687 			 * We don't support $ORIGIN on setid programs to close
688 			 * a potential attack vector.
689 			 */
690 			if ((setid & EXECSETID_SETID) != 0) {
691 				error = ENOEXEC;
692 				goto bad;
693 			}
694 
695 			curlen = 0;
696 			len = p - dlnp - 1;
697 			if (len) {
698 				bcopy(dlnp, pathbufp, len);
699 				curlen += len;
700 			}
701 			if (_ptr = strrchr(args->pathname, '/')) {
702 				len = _ptr - args->pathname;
703 				if ((curlen + len) > MAXPATHLEN)
704 					break;
705 
706 				bcopy(args->pathname, &pathbufp[curlen], len);
707 				curlen += len;
708 			} else {
709 				/*
710 				 * executable is a basename found in the
711 				 * current directory.  So - just substitue
712 				 * '.' for ORIGIN.
713 				 */
714 				pathbufp[curlen] = '.';
715 				curlen++;
716 			}
717 			p += ORIGIN_STR_SIZE;
718 			len = strlen(p);
719 
720 			if ((curlen + len) > MAXPATHLEN)
721 				break;
722 			bcopy(p, &pathbufp[curlen], len);
723 			curlen += len;
724 			pathbufp[curlen++] = '\0';
725 			bcopy(pathbufp, dlnp, curlen);
726 		}
727 
728 		/*
729 		 * /usr/lib/ld.so.1 is known to be a symlink to /lib/ld.so.1
730 		 * (and /usr/lib/64/ld.so.1 is a symlink to /lib/64/ld.so.1).
731 		 * Just in case /usr is not mounted, change it now.
732 		 */
733 		if (strcmp(dlnp, USR_LIB_RTLD) == 0)
734 			dlnp += 4;
735 		error = lookupname(dlnp, UIO_SYSSPACE, FOLLOW, NULLVPP, &nvp);
736 		if (error && dlnp != bigwad->dl_name) {
737 			/* new kernel, old user-level */
738 			error = lookupname(dlnp -= 4, UIO_SYSSPACE, FOLLOW,
739 			    NULLVPP, &nvp);
740 		}
741 		if (error) {
742 			uprintf("%s: Cannot find %s\n", exec_file, dlnp);
743 			goto bad;
744 		}
745 
746 		/*
747 		 * Setup the "aux" vector.
748 		 */
749 		if (uphdr) {
750 			if (ehdrp->e_type == ET_DYN) {
751 				/* don't use the first page */
752 				bigwad->exenv.ex_brkbase = (caddr_t)PAGESIZE;
753 				bigwad->exenv.ex_bssbase = (caddr_t)PAGESIZE;
754 			} else {
755 				bigwad->exenv.ex_bssbase = bssbase;
756 				bigwad->exenv.ex_brkbase = brkbase;
757 			}
758 			bigwad->exenv.ex_brksize = brksize;
759 			bigwad->exenv.ex_magic = elfmagic;
760 			bigwad->exenv.ex_vp = vp;
761 			setexecenv(&bigwad->exenv);
762 
763 			ADDAUX(aux, AT_PHDR, uphdr->p_vaddr + voffset)
764 			ADDAUX(aux, AT_PHENT, ehdrp->e_phentsize)
765 			ADDAUX(aux, AT_PHNUM, nphdrs)
766 			ADDAUX(aux, AT_ENTRY, ehdrp->e_entry + voffset)
767 		} else {
768 			if ((error = execopen(&vp, &fd)) != 0) {
769 				VN_RELE(nvp);
770 				goto bad;
771 			}
772 
773 			ADDAUX(aux, AT_EXECFD, fd)
774 		}
775 
776 		if ((error = execpermissions(nvp, &bigwad->vattr, args)) != 0) {
777 			VN_RELE(nvp);
778 			uprintf("%s: Cannot execute %s\n", exec_file, dlnp);
779 			goto bad;
780 		}
781 
782 		/*
783 		 * Now obtain the ELF header along with the entire program
784 		 * header contained in "nvp".
785 		 */
786 		kmem_free(phdrbase, phdrsize);
787 		phdrbase = NULL;
788 		if ((error = getelfhead(nvp, CRED(), ehdrp, &nshdrs,
789 		    &shstrndx, &nphdrs)) != 0 ||
790 		    (error = getelfphdr(nvp, CRED(), ehdrp, nphdrs, &phdrbase,
791 		    &phdrsize)) != 0) {
792 			VN_RELE(nvp);
793 			uprintf("%s: Cannot read %s\n", exec_file, dlnp);
794 			goto bad;
795 		}
796 
797 		/*
798 		 * Determine memory size of the "interpreter's" loadable
799 		 * sections.  This size is then used to obtain the virtual
800 		 * address of a hole, in the user's address space, large
801 		 * enough to map the "interpreter".
802 		 */
803 		if ((len = elfsize(ehdrp, nphdrs, phdrbase, &lddata)) == 0) {
804 			VN_RELE(nvp);
805 			uprintf("%s: Nothing to load in %s\n", exec_file, dlnp);
806 			goto bad;
807 		}
808 
809 		dtrphdr = NULL;
810 
811 		error = mapelfexec(nvp, ehdrp, nphdrs, phdrbase, &junk, &junk,
812 		    &junk, &dtrphdr, NULL, NULL, NULL, &voffset, NULL, len,
813 		    execsz, NULL);
814 		if (error || junk != NULL) {
815 			VN_RELE(nvp);
816 			uprintf("%s: Cannot map %s\n", exec_file, dlnp);
817 			goto bad;
818 		}
819 
820 		/*
821 		 * We use the DTrace program header to initialize the
822 		 * architecture-specific user per-LWP location. The dtrace
823 		 * fasttrap provider requires ready access to per-LWP scratch
824 		 * space. We assume that there is only one such program header
825 		 * in the interpreter.
826 		 */
827 		if (dtrphdr != NULL &&
828 		    dtrace_safe_phdr(dtrphdr, args, voffset) != 0) {
829 			VN_RELE(nvp);
830 			uprintf("%s: Bad DTrace phdr in %s\n", exec_file, dlnp);
831 			goto bad;
832 		}
833 
834 		VN_RELE(nvp);
835 		ADDAUX(aux, AT_SUN_LDDATA, voffset + lddata)
836 	}
837 
838 	if (hasauxv) {
839 		int auxf = AF_SUN_HWCAPVERIFY;
840 #if defined(__amd64)
841 		size_t fpsize;
842 		int fptype;
843 #endif /* defined(__amd64) */
844 
845 		/*
846 		 * Note: AT_SUN_PLATFORM and AT_SUN_EXECNAME were filled in via
847 		 * exec_args()
848 		 */
849 		ADDAUX(aux, AT_BASE, voffset)
850 		ADDAUX(aux, AT_FLAGS, at_flags)
851 		ADDAUX(aux, AT_PAGESZ, PAGESIZE)
852 		/*
853 		 * Linker flags. (security)
854 		 * p_flag not yet set at this time.
855 		 * We rely on gexec() to provide us with the information.
856 		 * If the application is set-uid but this is not reflected
857 		 * in a mismatch between real/effective uids/gids, then
858 		 * don't treat this as a set-uid exec.  So we care about
859 		 * the EXECSETID_UGIDS flag but not the ...SETID flag.
860 		 */
861 		if ((setid &= ~EXECSETID_SETID) != 0)
862 			auxf |= AF_SUN_SETUGID;
863 
864 		/*
865 		 * If we're running a native process from within a branded
866 		 * zone under pfexec then we clear the AF_SUN_SETUGID flag so
867 		 * that the native ld.so.1 is able to link with the native
868 		 * libraries instead of using the brand libraries that are
869 		 * installed in the zone.  We only do this for processes
870 		 * which we trust because we see they are already running
871 		 * under pfexec (where uid != euid).  This prevents a
872 		 * malicious user within the zone from crafting a wrapper to
873 		 * run native suid commands with unsecure libraries interposed.
874 		 */
875 		if ((brand_action == EBA_NATIVE) && (PROC_IS_BRANDED(p) &&
876 		    (setid &= ~EXECSETID_SETID) != 0))
877 			auxf &= ~AF_SUN_SETUGID;
878 
879 		/*
880 		 * Record the user addr of the auxflags aux vector entry
881 		 * since brands may optionally want to manipulate this field.
882 		 */
883 		args->auxp_auxflags =
884 		    (char *)((char *)args->stackend +
885 		    ((char *)&aux->a_type -
886 		    (char *)bigwad->elfargs));
887 		ADDAUX(aux, AT_SUN_AUXFLAGS, auxf);
888 
889 		/*
890 		 * Hardware capability flag word (performance hints)
891 		 * Used for choosing faster library routines.
892 		 * (Potentially different between 32-bit and 64-bit ABIs)
893 		 */
894 #if defined(_LP64)
895 		if (args->to_model == DATAMODEL_NATIVE) {
896 			ADDAUX(aux, AT_SUN_HWCAP, auxv_hwcap)
897 			ADDAUX(aux, AT_SUN_HWCAP2, auxv_hwcap_2)
898 		} else {
899 			ADDAUX(aux, AT_SUN_HWCAP, auxv_hwcap32)
900 			ADDAUX(aux, AT_SUN_HWCAP2, auxv_hwcap32_2)
901 		}
902 #else
903 		ADDAUX(aux, AT_SUN_HWCAP, auxv_hwcap)
904 		ADDAUX(aux, AT_SUN_HWCAP2, auxv_hwcap_2)
905 #endif
906 		if (branded) {
907 			/*
908 			 * Reserve space for the brand-private aux vectors,
909 			 * and record the user addr of that space.
910 			 */
911 			args->auxp_brand =
912 			    (char *)((char *)args->stackend +
913 			    ((char *)&aux->a_type -
914 			    (char *)bigwad->elfargs));
915 			ADDAUX(aux, AT_SUN_BRAND_AUX1, 0)
916 			ADDAUX(aux, AT_SUN_BRAND_AUX2, 0)
917 			ADDAUX(aux, AT_SUN_BRAND_AUX3, 0)
918 		}
919 
920 		/*
921 		 * Add the comm page auxv entry, mapping it in if needed. Also
922 		 * take care of the FPU entries.
923 		 */
924 #if defined(__amd64)
925 		if (args->commpage != NULL ||
926 		    (args->commpage = (uintptr_t)comm_page_mapin()) != NULL) {
927 			ADDAUX(aux, AT_SUN_COMMPAGE, args->commpage)
928 		} else {
929 			/*
930 			 * If the comm page cannot be mapped, pad out the auxv
931 			 * to satisfy later size checks.
932 			 */
933 			ADDAUX(aux, AT_NULL, 0)
934 		}
935 
936 		fptype = AT_386_FPINFO_NONE;
937 		fpu_auxv_info(&fptype, &fpsize);
938 		if (fptype != AT_386_FPINFO_NONE) {
939 			ADDAUX(aux, AT_SUN_FPTYPE, fptype)
940 			ADDAUX(aux, AT_SUN_FPSIZE, fpsize)
941 		} else {
942 			ADDAUX(aux, AT_NULL, 0)
943 			ADDAUX(aux, AT_NULL, 0)
944 		}
945 #endif /* defined(__amd64) */
946 
947 		ADDAUX(aux, AT_NULL, 0)
948 		postfixsize = (char *)aux - (char *)bigwad->elfargs;
949 
950 		/*
951 		 * We make assumptions above when we determine how many aux
952 		 * vector entries we will be adding. However, if we have an
953 		 * invalid elf file, it is possible that mapelfexec might
954 		 * behave differently (but not return an error), in which case
955 		 * the number of aux entries we actually add will be different.
956 		 * We detect that now and error out.
957 		 */
958 		if (postfixsize != args->auxsize) {
959 			DTRACE_PROBE2(elfexec_badaux, int, postfixsize,
960 			    int, args->auxsize);
961 			goto bad;
962 		}
963 		ASSERT(postfixsize <= __KERN_NAUXV_IMPL * sizeof (aux_entry_t));
964 	}
965 
966 	/*
967 	 * For the 64-bit kernel, the limit is big enough that rounding it up
968 	 * to a page can overflow the 64-bit limit, so we check for btopr()
969 	 * overflowing here by comparing it with the unrounded limit in pages.
970 	 * If it hasn't overflowed, compare the exec size with the rounded up
971 	 * limit in pages.  Otherwise, just compare with the unrounded limit.
972 	 */
973 	limit = btop(p->p_vmem_ctl);
974 	roundlimit = btopr(p->p_vmem_ctl);
975 	if ((roundlimit > limit && *execsz > roundlimit) ||
976 	    (roundlimit < limit && *execsz > limit)) {
977 		mutex_enter(&p->p_lock);
978 		(void) rctl_action(rctlproc_legacy[RLIMIT_VMEM], p->p_rctls, p,
979 		    RCA_SAFE);
980 		mutex_exit(&p->p_lock);
981 		error = ENOMEM;
982 		goto bad;
983 	}
984 
985 	bzero(up->u_auxv, sizeof (up->u_auxv));
986 	up->u_commpagep = args->commpage;
987 	if (postfixsize) {
988 		int num_auxv;
989 
990 		/*
991 		 * Copy the aux vector to the user stack.
992 		 */
993 		error = execpoststack(args, bigwad->elfargs, postfixsize);
994 		if (error)
995 			goto bad;
996 
997 		/*
998 		 * Copy auxv to the process's user structure for use by /proc.
999 		 * If this is a branded process, the brand's exec routine will
1000 		 * copy it's private entries to the user structure later. It
1001 		 * relies on the fact that the blank entries are at the end.
1002 		 */
1003 		num_auxv = postfixsize / sizeof (aux_entry_t);
1004 		ASSERT(num_auxv <= sizeof (up->u_auxv) / sizeof (auxv_t));
1005 		aux = bigwad->elfargs;
1006 		for (i = 0; i < num_auxv; i++) {
1007 			up->u_auxv[i].a_type = aux[i].a_type;
1008 			up->u_auxv[i].a_un.a_val = (aux_val_t)aux[i].a_un.a_val;
1009 		}
1010 	}
1011 
1012 	/*
1013 	 * Pass back the starting address so we can set the program counter.
1014 	 */
1015 	args->entry = (uintptr_t)(ehdrp->e_entry + voffset);
1016 
1017 	if (!uphdr) {
1018 		if (ehdrp->e_type == ET_DYN) {
1019 			/*
1020 			 * If we are executing a shared library which doesn't
1021 			 * have a interpreter (probably ld.so.1) then
1022 			 * we don't set the brkbase now.  Instead we
1023 			 * delay it's setting until the first call
1024 			 * via grow.c::brk().  This permits ld.so.1 to
1025 			 * initialize brkbase to the tail of the executable it
1026 			 * loads (which is where it needs to be).
1027 			 */
1028 			bigwad->exenv.ex_brkbase = (caddr_t)0;
1029 			bigwad->exenv.ex_bssbase = (caddr_t)0;
1030 			bigwad->exenv.ex_brksize = 0;
1031 		} else {
1032 			bigwad->exenv.ex_brkbase = brkbase;
1033 			bigwad->exenv.ex_bssbase = bssbase;
1034 			bigwad->exenv.ex_brksize = brksize;
1035 		}
1036 		bigwad->exenv.ex_magic = elfmagic;
1037 		bigwad->exenv.ex_vp = vp;
1038 		setexecenv(&bigwad->exenv);
1039 	}
1040 
1041 	ASSERT(error == 0);
1042 	goto out;
1043 
1044 bad:
1045 	if (fd != -1)		/* did we open the a.out yet */
1046 		(void) execclose(fd);
1047 
1048 	psignal(p, SIGKILL);
1049 
1050 	if (error == 0)
1051 		error = ENOEXEC;
1052 out:
1053 	if (phdrbase != NULL)
1054 		kmem_free(phdrbase, phdrsize);
1055 	if (cap != NULL)
1056 		kmem_free(cap, capsize);
1057 	kmem_free(bigwad, sizeof (struct bigwad));
1058 	return (error);
1059 }
1060 
1061 /*
1062  * Compute the memory size requirement for the ELF file.
1063  */
1064 static size_t
1065 elfsize(Ehdr *ehdrp, int nphdrs, caddr_t phdrbase, uintptr_t *lddata)
1066 {
1067 	size_t	len;
1068 	Phdr	*phdrp = (Phdr *)phdrbase;
1069 	int	hsize = ehdrp->e_phentsize;
1070 	int	first = 1;
1071 	int	dfirst = 1;	/* first data segment */
1072 	uintptr_t loaddr = 0;
1073 	uintptr_t hiaddr = 0;
1074 	uintptr_t lo, hi;
1075 	int	i;
1076 
1077 	for (i = nphdrs; i > 0; i--) {
1078 		if (phdrp->p_type == PT_LOAD) {
1079 			lo = phdrp->p_vaddr;
1080 			hi = lo + phdrp->p_memsz;
1081 			if (first) {
1082 				loaddr = lo;
1083 				hiaddr = hi;
1084 				first = 0;
1085 			} else {
1086 				if (loaddr > lo)
1087 					loaddr = lo;
1088 				if (hiaddr < hi)
1089 					hiaddr = hi;
1090 			}
1091 
1092 			/*
1093 			 * save the address of the first data segment
1094 			 * of a object - used for the AT_SUNW_LDDATA
1095 			 * aux entry.
1096 			 */
1097 			if ((lddata != NULL) && dfirst &&
1098 			    (phdrp->p_flags & PF_W)) {
1099 				*lddata = lo;
1100 				dfirst = 0;
1101 			}
1102 		}
1103 		phdrp = (Phdr *)((caddr_t)phdrp + hsize);
1104 	}
1105 
1106 	len = hiaddr - (loaddr & PAGEMASK);
1107 	len = roundup(len, PAGESIZE);
1108 
1109 	return (len);
1110 }
1111 
1112 /*
1113  * Read in the ELF header and program header table.
1114  * SUSV3 requires:
1115  *	ENOEXEC	File format is not recognized
1116  *	EINVAL	Format recognized but execution not supported
1117  */
1118 static int
1119 getelfhead(vnode_t *vp, cred_t *credp, Ehdr *ehdr, int *nshdrs, int *shstrndx,
1120     int *nphdrs)
1121 {
1122 	int error;
1123 	ssize_t resid;
1124 
1125 	/*
1126 	 * We got here by the first two bytes in ident,
1127 	 * now read the entire ELF header.
1128 	 */
1129 	if ((error = vn_rdwr(UIO_READ, vp, (caddr_t)ehdr,
1130 	    sizeof (Ehdr), (offset_t)0, UIO_SYSSPACE, 0,
1131 	    (rlim64_t)0, credp, &resid)) != 0)
1132 		return (error);
1133 
1134 	/*
1135 	 * Since a separate version is compiled for handling 32-bit and
1136 	 * 64-bit ELF executables on a 64-bit kernel, the 64-bit version
1137 	 * doesn't need to be able to deal with 32-bit ELF files.
1138 	 */
1139 	if (resid != 0 ||
1140 	    ehdr->e_ident[EI_MAG2] != ELFMAG2 ||
1141 	    ehdr->e_ident[EI_MAG3] != ELFMAG3)
1142 		return (ENOEXEC);
1143 
1144 	if ((ehdr->e_type != ET_EXEC && ehdr->e_type != ET_DYN) ||
1145 #if defined(_ILP32) || defined(_ELF32_COMPAT)
1146 	    ehdr->e_ident[EI_CLASS] != ELFCLASS32 ||
1147 #else
1148 	    ehdr->e_ident[EI_CLASS] != ELFCLASS64 ||
1149 #endif
1150 	    !elfheadcheck(ehdr->e_ident[EI_DATA], ehdr->e_machine,
1151 	    ehdr->e_flags))
1152 		return (EINVAL);
1153 
1154 	*nshdrs = ehdr->e_shnum;
1155 	*shstrndx = ehdr->e_shstrndx;
1156 	*nphdrs = ehdr->e_phnum;
1157 
1158 	/*
1159 	 * If e_shnum, e_shstrndx, or e_phnum is its sentinel value, we need
1160 	 * to read in the section header at index zero to acces the true
1161 	 * values for those fields.
1162 	 */
1163 	if ((*nshdrs == 0 && ehdr->e_shoff != 0) ||
1164 	    *shstrndx == SHN_XINDEX || *nphdrs == PN_XNUM) {
1165 		Shdr shdr;
1166 
1167 		if (ehdr->e_shoff == 0)
1168 			return (EINVAL);
1169 
1170 		if ((error = vn_rdwr(UIO_READ, vp, (caddr_t)&shdr,
1171 		    sizeof (shdr), (offset_t)ehdr->e_shoff, UIO_SYSSPACE, 0,
1172 		    (rlim64_t)0, credp, &resid)) != 0)
1173 			return (error);
1174 
1175 		if (*nshdrs == 0)
1176 			*nshdrs = shdr.sh_size;
1177 		if (*shstrndx == SHN_XINDEX)
1178 			*shstrndx = shdr.sh_link;
1179 		if (*nphdrs == PN_XNUM && shdr.sh_info != 0)
1180 			*nphdrs = shdr.sh_info;
1181 	}
1182 
1183 	return (0);
1184 }
1185 
1186 #ifdef _ELF32_COMPAT
1187 extern size_t elf_nphdr_max;
1188 #else
1189 size_t elf_nphdr_max = 1000;
1190 #endif
1191 
1192 static int
1193 getelfphdr(vnode_t *vp, cred_t *credp, const Ehdr *ehdr, int nphdrs,
1194     caddr_t *phbasep, ssize_t *phsizep)
1195 {
1196 	ssize_t resid, minsize;
1197 	int err;
1198 
1199 	/*
1200 	 * Since we're going to be using e_phentsize to iterate down the
1201 	 * array of program headers, it must be 8-byte aligned or else
1202 	 * a we might cause a misaligned access. We use all members through
1203 	 * p_flags on 32-bit ELF files and p_memsz on 64-bit ELF files so
1204 	 * e_phentsize must be at least large enough to include those
1205 	 * members.
1206 	 */
1207 #if !defined(_LP64) || defined(_ELF32_COMPAT)
1208 	minsize = offsetof(Phdr, p_flags) + sizeof (((Phdr *)NULL)->p_flags);
1209 #else
1210 	minsize = offsetof(Phdr, p_memsz) + sizeof (((Phdr *)NULL)->p_memsz);
1211 #endif
1212 	if (ehdr->e_phentsize < minsize || (ehdr->e_phentsize & 3))
1213 		return (EINVAL);
1214 
1215 	*phsizep = nphdrs * ehdr->e_phentsize;
1216 
1217 	if (*phsizep > sizeof (Phdr) * elf_nphdr_max) {
1218 		if ((*phbasep = kmem_alloc(*phsizep, KM_NOSLEEP)) == NULL)
1219 			return (ENOMEM);
1220 	} else {
1221 		*phbasep = kmem_alloc(*phsizep, KM_SLEEP);
1222 	}
1223 
1224 	if ((err = vn_rdwr(UIO_READ, vp, *phbasep, *phsizep,
1225 	    (offset_t)ehdr->e_phoff, UIO_SYSSPACE, 0, (rlim64_t)0,
1226 	    credp, &resid)) != 0) {
1227 		kmem_free(*phbasep, *phsizep);
1228 		*phbasep = NULL;
1229 		return (err);
1230 	}
1231 
1232 	return (0);
1233 }
1234 
1235 #ifdef _ELF32_COMPAT
1236 extern size_t elf_nshdr_max;
1237 extern size_t elf_shstrtab_max;
1238 #else
1239 size_t elf_nshdr_max = 10000;
1240 size_t elf_shstrtab_max = 100 * 1024;
1241 #endif
1242 
1243 
1244 static int
1245 getelfshdr(vnode_t *vp, cred_t *credp, const Ehdr *ehdr,
1246     int nshdrs, int shstrndx, caddr_t *shbasep, ssize_t *shsizep,
1247     char **shstrbasep, ssize_t *shstrsizep)
1248 {
1249 	ssize_t resid, minsize;
1250 	int err;
1251 	Shdr *shdr;
1252 
1253 	/*
1254 	 * Since we're going to be using e_shentsize to iterate down the
1255 	 * array of section headers, it must be 8-byte aligned or else
1256 	 * a we might cause a misaligned access. We use all members through
1257 	 * sh_entsize (on both 32- and 64-bit ELF files) so e_shentsize
1258 	 * must be at least large enough to include that member. The index
1259 	 * of the string table section must also be valid.
1260 	 */
1261 	minsize = offsetof(Shdr, sh_entsize) + sizeof (shdr->sh_entsize);
1262 	if (ehdr->e_shentsize < minsize || (ehdr->e_shentsize & 3) ||
1263 	    shstrndx >= nshdrs)
1264 		return (EINVAL);
1265 
1266 	*shsizep = nshdrs * ehdr->e_shentsize;
1267 
1268 	if (*shsizep > sizeof (Shdr) * elf_nshdr_max) {
1269 		if ((*shbasep = kmem_alloc(*shsizep, KM_NOSLEEP)) == NULL)
1270 			return (ENOMEM);
1271 	} else {
1272 		*shbasep = kmem_alloc(*shsizep, KM_SLEEP);
1273 	}
1274 
1275 	if ((err = vn_rdwr(UIO_READ, vp, *shbasep, *shsizep,
1276 	    (offset_t)ehdr->e_shoff, UIO_SYSSPACE, 0, (rlim64_t)0,
1277 	    credp, &resid)) != 0) {
1278 		kmem_free(*shbasep, *shsizep);
1279 		return (err);
1280 	}
1281 
1282 	/*
1283 	 * Pull the section string table out of the vnode; fail if the size
1284 	 * is zero.
1285 	 */
1286 	shdr = (Shdr *)(*shbasep + shstrndx * ehdr->e_shentsize);
1287 	if ((*shstrsizep = shdr->sh_size) == 0) {
1288 		kmem_free(*shbasep, *shsizep);
1289 		return (EINVAL);
1290 	}
1291 
1292 	if (*shstrsizep > elf_shstrtab_max) {
1293 		if ((*shstrbasep = kmem_alloc(*shstrsizep,
1294 		    KM_NOSLEEP)) == NULL) {
1295 			kmem_free(*shbasep, *shsizep);
1296 			return (ENOMEM);
1297 		}
1298 	} else {
1299 		*shstrbasep = kmem_alloc(*shstrsizep, KM_SLEEP);
1300 	}
1301 
1302 	if ((err = vn_rdwr(UIO_READ, vp, *shstrbasep, *shstrsizep,
1303 	    (offset_t)shdr->sh_offset, UIO_SYSSPACE, 0, (rlim64_t)0,
1304 	    credp, &resid)) != 0) {
1305 		kmem_free(*shbasep, *shsizep);
1306 		kmem_free(*shstrbasep, *shstrsizep);
1307 		return (err);
1308 	}
1309 
1310 	/*
1311 	 * Make sure the strtab is null-terminated to make sure we
1312 	 * don't run off the end of the table.
1313 	 */
1314 	(*shstrbasep)[*shstrsizep - 1] = '\0';
1315 
1316 	return (0);
1317 }
1318 
1319 static int
1320 mapelfexec(
1321 	vnode_t *vp,
1322 	Ehdr *ehdr,
1323 	int nphdrs,
1324 	caddr_t phdrbase,
1325 	Phdr **uphdr,
1326 	Phdr **intphdr,
1327 	Phdr **stphdr,
1328 	Phdr **dtphdr,
1329 	Phdr *dataphdrp,
1330 	caddr_t *bssbase,
1331 	caddr_t *brkbase,
1332 	intptr_t *voffset,
1333 	intptr_t *minaddr,
1334 	size_t len,
1335 	long *execsz,
1336 	size_t *brksize)
1337 {
1338 	Phdr *phdr;
1339 	int i, prot, error;
1340 	caddr_t addr = NULL;
1341 	size_t zfodsz;
1342 	int ptload = 0;
1343 	int page;
1344 	off_t offset;
1345 	int hsize = ehdr->e_phentsize;
1346 	caddr_t mintmp = (caddr_t)-1;
1347 	extern int use_brk_lpg;
1348 
1349 	if (ehdr->e_type == ET_DYN) {
1350 		secflagset_t flags = 0;
1351 		/*
1352 		 * Obtain the virtual address of a hole in the
1353 		 * address space to map the "interpreter".
1354 		 */
1355 		if (secflag_enabled(curproc, PROC_SEC_ASLR))
1356 			flags |= _MAP_RANDOMIZE;
1357 
1358 		map_addr(&addr, len, (offset_t)0, 1, flags);
1359 		if (addr == NULL)
1360 			return (ENOMEM);
1361 		*voffset = (intptr_t)addr;
1362 
1363 		/*
1364 		 * Calculate the minimum vaddr so it can be subtracted out.
1365 		 * According to the ELF specification, since PT_LOAD sections
1366 		 * must be sorted by increasing p_vaddr values, this is
1367 		 * guaranteed to be the first PT_LOAD section.
1368 		 */
1369 		phdr = (Phdr *)phdrbase;
1370 		for (i = nphdrs; i > 0; i--) {
1371 			if (phdr->p_type == PT_LOAD) {
1372 				*voffset -= (uintptr_t)phdr->p_vaddr;
1373 				break;
1374 			}
1375 			phdr = (Phdr *)((caddr_t)phdr + hsize);
1376 		}
1377 
1378 	} else {
1379 		*voffset = 0;
1380 	}
1381 	phdr = (Phdr *)phdrbase;
1382 	for (i = nphdrs; i > 0; i--) {
1383 		switch (phdr->p_type) {
1384 		case PT_LOAD:
1385 			if ((*intphdr != NULL) && (*uphdr == NULL))
1386 				return (0);
1387 
1388 			ptload = 1;
1389 			prot = PROT_USER;
1390 			if (phdr->p_flags & PF_R)
1391 				prot |= PROT_READ;
1392 			if (phdr->p_flags & PF_W)
1393 				prot |= PROT_WRITE;
1394 			if (phdr->p_flags & PF_X)
1395 				prot |= PROT_EXEC;
1396 
1397 			addr = (caddr_t)((uintptr_t)phdr->p_vaddr + *voffset);
1398 
1399 			/*
1400 			 * Keep track of the segment with the lowest starting
1401 			 * address.
1402 			 */
1403 			if (addr < mintmp)
1404 				mintmp = addr;
1405 
1406 			zfodsz = (size_t)phdr->p_memsz - phdr->p_filesz;
1407 
1408 			offset = phdr->p_offset;
1409 			if (((uintptr_t)offset & PAGEOFFSET) ==
1410 			    ((uintptr_t)addr & PAGEOFFSET) &&
1411 			    (!(vp->v_flag & VNOMAP))) {
1412 				page = 1;
1413 			} else {
1414 				page = 0;
1415 			}
1416 
1417 			/*
1418 			 * Set the heap pagesize for OOB when the bss size
1419 			 * is known and use_brk_lpg is not 0.
1420 			 */
1421 			if (brksize != NULL && use_brk_lpg &&
1422 			    zfodsz != 0 && phdr == dataphdrp &&
1423 			    (prot & PROT_WRITE)) {
1424 				size_t tlen = P2NPHASE((uintptr_t)addr +
1425 				    phdr->p_filesz, PAGESIZE);
1426 
1427 				if (zfodsz > tlen) {
1428 					curproc->p_brkpageszc =
1429 					    page_szc(map_pgsz(MAPPGSZ_HEAP,
1430 					    curproc, addr + phdr->p_filesz +
1431 					    tlen, zfodsz - tlen, 0));
1432 				}
1433 			}
1434 
1435 			if (curproc->p_brkpageszc != 0 && phdr == dataphdrp &&
1436 			    (prot & PROT_WRITE)) {
1437 				uint_t	szc = curproc->p_brkpageszc;
1438 				size_t pgsz = page_get_pagesize(szc);
1439 				caddr_t ebss = addr + phdr->p_memsz;
1440 				/*
1441 				 * If we need extra space to keep the BSS an
1442 				 * integral number of pages in size, some of
1443 				 * that space may fall beyond p_brkbase, so we
1444 				 * need to set p_brksize to account for it
1445 				 * being (logically) part of the brk.
1446 				 */
1447 				size_t extra_zfodsz;
1448 
1449 				ASSERT(pgsz > PAGESIZE);
1450 
1451 				extra_zfodsz = P2NPHASE((uintptr_t)ebss, pgsz);
1452 
1453 				if (error = execmap(vp, addr, phdr->p_filesz,
1454 				    zfodsz + extra_zfodsz, phdr->p_offset,
1455 				    prot, page, szc))
1456 					goto bad;
1457 				if (brksize != NULL)
1458 					*brksize = extra_zfodsz;
1459 			} else {
1460 				if (error = execmap(vp, addr, phdr->p_filesz,
1461 				    zfodsz, phdr->p_offset, prot, page, 0))
1462 					goto bad;
1463 			}
1464 
1465 			if (bssbase != NULL && addr >= *bssbase &&
1466 			    phdr == dataphdrp) {
1467 				*bssbase = addr + phdr->p_filesz;
1468 			}
1469 			if (brkbase != NULL && addr >= *brkbase) {
1470 				*brkbase = addr + phdr->p_memsz;
1471 			}
1472 
1473 			*execsz += btopr(phdr->p_memsz);
1474 			break;
1475 
1476 		case PT_INTERP:
1477 			if (ptload)
1478 				goto bad;
1479 			*intphdr = phdr;
1480 			break;
1481 
1482 		case PT_SHLIB:
1483 			*stphdr = phdr;
1484 			break;
1485 
1486 		case PT_PHDR:
1487 			if (ptload)
1488 				goto bad;
1489 			*uphdr = phdr;
1490 			break;
1491 
1492 		case PT_NULL:
1493 		case PT_DYNAMIC:
1494 		case PT_NOTE:
1495 			break;
1496 
1497 		case PT_SUNWDTRACE:
1498 			if (dtphdr != NULL)
1499 				*dtphdr = phdr;
1500 			break;
1501 
1502 		default:
1503 			break;
1504 		}
1505 		phdr = (Phdr *)((caddr_t)phdr + hsize);
1506 	}
1507 
1508 	if (minaddr != NULL) {
1509 		ASSERT(mintmp != (caddr_t)-1);
1510 		*minaddr = (intptr_t)mintmp;
1511 	}
1512 
1513 	if (brkbase != NULL && secflag_enabled(curproc, PROC_SEC_ASLR)) {
1514 		size_t off;
1515 		uintptr_t base = (uintptr_t)*brkbase;
1516 		uintptr_t oend = base + *brksize;
1517 
1518 		ASSERT(ISP2(aslr_max_brk_skew));
1519 
1520 		(void) random_get_pseudo_bytes((uint8_t *)&off, sizeof (off));
1521 		base += P2PHASE(off, aslr_max_brk_skew);
1522 		base = P2ROUNDUP(base, PAGESIZE);
1523 		*brkbase = (caddr_t)base;
1524 		/*
1525 		 * Above, we set *brksize to account for the possibility we
1526 		 * had to grow the 'brk' in padding out the BSS to a page
1527 		 * boundary.
1528 		 *
1529 		 * We now need to adjust that based on where we now are
1530 		 * actually putting the brk.
1531 		 */
1532 		if (oend > base)
1533 			*brksize = oend - base;
1534 		else
1535 			*brksize = 0;
1536 	}
1537 
1538 	return (0);
1539 bad:
1540 	if (error == 0)
1541 		error = EINVAL;
1542 	return (error);
1543 }
1544 
1545 int
1546 elfnote(vnode_t *vp, offset_t *offsetp, int type, int descsz, void *desc,
1547     rlim64_t rlimit, cred_t *credp)
1548 {
1549 	Note note;
1550 	int error;
1551 
1552 	bzero(&note, sizeof (note));
1553 	bcopy("CORE", note.name, 4);
1554 	note.nhdr.n_type = type;
1555 	/*
1556 	 * The System V ABI states that n_namesz must be the length of the
1557 	 * string that follows the Nhdr structure including the terminating
1558 	 * null. The ABI also specifies that sufficient padding should be
1559 	 * included so that the description that follows the name string
1560 	 * begins on a 4- or 8-byte boundary for 32- and 64-bit binaries
1561 	 * respectively. However, since this change was not made correctly
1562 	 * at the time of the 64-bit port, both 32- and 64-bit binaries
1563 	 * descriptions are only guaranteed to begin on a 4-byte boundary.
1564 	 */
1565 	note.nhdr.n_namesz = 5;
1566 	note.nhdr.n_descsz = roundup(descsz, sizeof (Word));
1567 
1568 	if (error = core_write(vp, UIO_SYSSPACE, *offsetp, &note,
1569 	    sizeof (note), rlimit, credp))
1570 		return (error);
1571 
1572 	*offsetp += sizeof (note);
1573 
1574 	if (error = core_write(vp, UIO_SYSSPACE, *offsetp, desc,
1575 	    note.nhdr.n_descsz, rlimit, credp))
1576 		return (error);
1577 
1578 	*offsetp += note.nhdr.n_descsz;
1579 	return (0);
1580 }
1581 
1582 /*
1583  * Copy the section data from one vnode to the section of another vnode.
1584  */
1585 static void
1586 copy_scn(Shdr *src, vnode_t *src_vp, Shdr *dst, vnode_t *dst_vp, Off *doffset,
1587     void *buf, size_t size, cred_t *credp, rlim64_t rlimit)
1588 {
1589 	ssize_t resid;
1590 	size_t len, n = src->sh_size;
1591 	offset_t off = 0;
1592 
1593 	while (n != 0) {
1594 		len = MIN(size, n);
1595 		if (vn_rdwr(UIO_READ, src_vp, buf, len, src->sh_offset + off,
1596 		    UIO_SYSSPACE, 0, (rlim64_t)0, credp, &resid) != 0 ||
1597 		    resid >= len ||
1598 		    core_write(dst_vp, UIO_SYSSPACE, *doffset + off,
1599 		    buf, len - resid, rlimit, credp) != 0) {
1600 			dst->sh_size = 0;
1601 			dst->sh_offset = 0;
1602 			return;
1603 		}
1604 
1605 		ASSERT(n >= len - resid);
1606 
1607 		n -= len - resid;
1608 		off += len - resid;
1609 	}
1610 
1611 	*doffset += src->sh_size;
1612 }
1613 
1614 #ifdef _ELF32_COMPAT
1615 extern size_t elf_datasz_max;
1616 #else
1617 size_t elf_datasz_max = 1 * 1024 * 1024;
1618 #endif
1619 
1620 /*
1621  * This function processes mappings that correspond to load objects to
1622  * examine their respective sections for elfcore(). It's called once with
1623  * v set to NULL to count the number of sections that we're going to need
1624  * and then again with v set to some allocated buffer that we fill in with
1625  * all the section data.
1626  */
1627 static int
1628 process_scns(core_content_t content, proc_t *p, cred_t *credp, vnode_t *vp,
1629     Shdr *v, int nv, rlim64_t rlimit, Off *doffsetp, int *nshdrsp)
1630 {
1631 	vnode_t *lastvp = NULL;
1632 	struct seg *seg;
1633 	int i, j;
1634 	void *data = NULL;
1635 	size_t datasz = 0;
1636 	shstrtab_t shstrtab;
1637 	struct as *as = p->p_as;
1638 	int error = 0;
1639 
1640 	if (v != NULL)
1641 		shstrtab_init(&shstrtab);
1642 
1643 	i = 1;
1644 	for (seg = AS_SEGFIRST(as); seg != NULL; seg = AS_SEGNEXT(as, seg)) {
1645 		uint_t prot;
1646 		vnode_t *mvp;
1647 		void *tmp = NULL;
1648 		caddr_t saddr = seg->s_base;
1649 		caddr_t naddr;
1650 		caddr_t eaddr;
1651 		size_t segsize;
1652 
1653 		Ehdr ehdr;
1654 		int nshdrs, shstrndx, nphdrs;
1655 		caddr_t shbase;
1656 		ssize_t shsize;
1657 		char *shstrbase;
1658 		ssize_t shstrsize;
1659 
1660 		Shdr *shdr;
1661 		const char *name;
1662 		size_t sz;
1663 		uintptr_t off;
1664 
1665 		int ctf_ndx = 0;
1666 		int symtab_ndx = 0;
1667 
1668 		/*
1669 		 * Since we're just looking for text segments of load
1670 		 * objects, we only care about the protection bits; we don't
1671 		 * care about the actual size of the segment so we use the
1672 		 * reserved size. If the segment's size is zero, there's
1673 		 * something fishy going on so we ignore this segment.
1674 		 */
1675 		if (seg->s_ops != &segvn_ops ||
1676 		    SEGOP_GETVP(seg, seg->s_base, &mvp) != 0 ||
1677 		    mvp == lastvp || mvp == NULL || mvp->v_type != VREG ||
1678 		    (segsize = pr_getsegsize(seg, 1)) == 0)
1679 			continue;
1680 
1681 		eaddr = saddr + segsize;
1682 		prot = pr_getprot(seg, 1, &tmp, &saddr, &naddr, eaddr);
1683 		pr_getprot_done(&tmp);
1684 
1685 		/*
1686 		 * Skip this segment unless the protection bits look like
1687 		 * what we'd expect for a text segment.
1688 		 */
1689 		if ((prot & (PROT_WRITE | PROT_EXEC)) != PROT_EXEC)
1690 			continue;
1691 
1692 		if (getelfhead(mvp, credp, &ehdr, &nshdrs, &shstrndx,
1693 		    &nphdrs) != 0 ||
1694 		    getelfshdr(mvp, credp, &ehdr, nshdrs, shstrndx,
1695 		    &shbase, &shsize, &shstrbase, &shstrsize) != 0)
1696 			continue;
1697 
1698 		off = ehdr.e_shentsize;
1699 		for (j = 1; j < nshdrs; j++, off += ehdr.e_shentsize) {
1700 			Shdr *symtab = NULL, *strtab;
1701 
1702 			shdr = (Shdr *)(shbase + off);
1703 
1704 			if (shdr->sh_name >= shstrsize)
1705 				continue;
1706 
1707 			name = shstrbase + shdr->sh_name;
1708 
1709 			if (strcmp(name, shstrtab_data[STR_CTF]) == 0) {
1710 				if ((content & CC_CONTENT_CTF) == 0 ||
1711 				    ctf_ndx != 0)
1712 					continue;
1713 
1714 				if (shdr->sh_link > 0 &&
1715 				    shdr->sh_link < nshdrs) {
1716 					symtab = (Shdr *)(shbase +
1717 					    shdr->sh_link * ehdr.e_shentsize);
1718 				}
1719 
1720 				if (v != NULL && i < nv - 1) {
1721 					if (shdr->sh_size > datasz &&
1722 					    shdr->sh_size <= elf_datasz_max) {
1723 						if (data != NULL)
1724 							kmem_free(data, datasz);
1725 
1726 						datasz = shdr->sh_size;
1727 						data = kmem_alloc(datasz,
1728 						    KM_SLEEP);
1729 					}
1730 
1731 					v[i].sh_name = shstrtab_ndx(&shstrtab,
1732 					    STR_CTF);
1733 					v[i].sh_addr = (Addr)(uintptr_t)saddr;
1734 					v[i].sh_type = SHT_PROGBITS;
1735 					v[i].sh_addralign = 4;
1736 					*doffsetp = roundup(*doffsetp,
1737 					    v[i].sh_addralign);
1738 					v[i].sh_offset = *doffsetp;
1739 					v[i].sh_size = shdr->sh_size;
1740 					if (symtab == NULL)  {
1741 						v[i].sh_link = 0;
1742 					} else if (symtab->sh_type ==
1743 					    SHT_SYMTAB &&
1744 					    symtab_ndx != 0) {
1745 						v[i].sh_link =
1746 						    symtab_ndx;
1747 					} else {
1748 						v[i].sh_link = i + 1;
1749 					}
1750 
1751 					copy_scn(shdr, mvp, &v[i], vp,
1752 					    doffsetp, data, datasz, credp,
1753 					    rlimit);
1754 				}
1755 
1756 				ctf_ndx = i++;
1757 
1758 				/*
1759 				 * We've already dumped the symtab.
1760 				 */
1761 				if (symtab != NULL &&
1762 				    symtab->sh_type == SHT_SYMTAB &&
1763 				    symtab_ndx != 0)
1764 					continue;
1765 
1766 			} else if (strcmp(name,
1767 			    shstrtab_data[STR_SYMTAB]) == 0) {
1768 				if ((content & CC_CONTENT_SYMTAB) == 0 ||
1769 				    symtab != 0)
1770 					continue;
1771 
1772 				symtab = shdr;
1773 			}
1774 
1775 			if (symtab != NULL) {
1776 				if ((symtab->sh_type != SHT_DYNSYM &&
1777 				    symtab->sh_type != SHT_SYMTAB) ||
1778 				    symtab->sh_link == 0 ||
1779 				    symtab->sh_link >= nshdrs)
1780 					continue;
1781 
1782 				strtab = (Shdr *)(shbase +
1783 				    symtab->sh_link * ehdr.e_shentsize);
1784 
1785 				if (strtab->sh_type != SHT_STRTAB)
1786 					continue;
1787 
1788 				if (v != NULL && i < nv - 2) {
1789 					sz = MAX(symtab->sh_size,
1790 					    strtab->sh_size);
1791 					if (sz > datasz &&
1792 					    sz <= elf_datasz_max) {
1793 						if (data != NULL)
1794 							kmem_free(data, datasz);
1795 
1796 						datasz = sz;
1797 						data = kmem_alloc(datasz,
1798 						    KM_SLEEP);
1799 					}
1800 
1801 					if (symtab->sh_type == SHT_DYNSYM) {
1802 						v[i].sh_name = shstrtab_ndx(
1803 						    &shstrtab, STR_DYNSYM);
1804 						v[i + 1].sh_name = shstrtab_ndx(
1805 						    &shstrtab, STR_DYNSTR);
1806 					} else {
1807 						v[i].sh_name = shstrtab_ndx(
1808 						    &shstrtab, STR_SYMTAB);
1809 						v[i + 1].sh_name = shstrtab_ndx(
1810 						    &shstrtab, STR_STRTAB);
1811 					}
1812 
1813 					v[i].sh_type = symtab->sh_type;
1814 					v[i].sh_addr = symtab->sh_addr;
1815 					if (ehdr.e_type == ET_DYN ||
1816 					    v[i].sh_addr == 0)
1817 						v[i].sh_addr +=
1818 						    (Addr)(uintptr_t)saddr;
1819 					v[i].sh_addralign =
1820 					    symtab->sh_addralign;
1821 					*doffsetp = roundup(*doffsetp,
1822 					    v[i].sh_addralign);
1823 					v[i].sh_offset = *doffsetp;
1824 					v[i].sh_size = symtab->sh_size;
1825 					v[i].sh_link = i + 1;
1826 					v[i].sh_entsize = symtab->sh_entsize;
1827 					v[i].sh_info = symtab->sh_info;
1828 
1829 					copy_scn(symtab, mvp, &v[i], vp,
1830 					    doffsetp, data, datasz, credp,
1831 					    rlimit);
1832 
1833 					v[i + 1].sh_type = SHT_STRTAB;
1834 					v[i + 1].sh_flags = SHF_STRINGS;
1835 					v[i + 1].sh_addr = symtab->sh_addr;
1836 					if (ehdr.e_type == ET_DYN ||
1837 					    v[i + 1].sh_addr == 0)
1838 						v[i + 1].sh_addr +=
1839 						    (Addr)(uintptr_t)saddr;
1840 					v[i + 1].sh_addralign =
1841 					    strtab->sh_addralign;
1842 					*doffsetp = roundup(*doffsetp,
1843 					    v[i + 1].sh_addralign);
1844 					v[i + 1].sh_offset = *doffsetp;
1845 					v[i + 1].sh_size = strtab->sh_size;
1846 
1847 					copy_scn(strtab, mvp, &v[i + 1], vp,
1848 					    doffsetp, data, datasz, credp,
1849 					    rlimit);
1850 				}
1851 
1852 				if (symtab->sh_type == SHT_SYMTAB)
1853 					symtab_ndx = i;
1854 				i += 2;
1855 			}
1856 		}
1857 
1858 		kmem_free(shstrbase, shstrsize);
1859 		kmem_free(shbase, shsize);
1860 
1861 		lastvp = mvp;
1862 	}
1863 
1864 	if (v == NULL) {
1865 		if (i == 1)
1866 			*nshdrsp = 0;
1867 		else
1868 			*nshdrsp = i + 1;
1869 		goto done;
1870 	}
1871 
1872 	if (i != nv - 1) {
1873 		cmn_err(CE_WARN, "elfcore: core dump failed for "
1874 		    "process %d; address space is changing", p->p_pid);
1875 		error = EIO;
1876 		goto done;
1877 	}
1878 
1879 	v[i].sh_name = shstrtab_ndx(&shstrtab, STR_SHSTRTAB);
1880 	v[i].sh_size = shstrtab_size(&shstrtab);
1881 	v[i].sh_addralign = 1;
1882 	*doffsetp = roundup(*doffsetp, v[i].sh_addralign);
1883 	v[i].sh_offset = *doffsetp;
1884 	v[i].sh_flags = SHF_STRINGS;
1885 	v[i].sh_type = SHT_STRTAB;
1886 
1887 	if (v[i].sh_size > datasz) {
1888 		if (data != NULL)
1889 			kmem_free(data, datasz);
1890 
1891 		datasz = v[i].sh_size;
1892 		data = kmem_alloc(datasz,
1893 		    KM_SLEEP);
1894 	}
1895 
1896 	shstrtab_dump(&shstrtab, data);
1897 
1898 	if ((error = core_write(vp, UIO_SYSSPACE, *doffsetp,
1899 	    data, v[i].sh_size, rlimit, credp)) != 0)
1900 		goto done;
1901 
1902 	*doffsetp += v[i].sh_size;
1903 
1904 done:
1905 	if (data != NULL)
1906 		kmem_free(data, datasz);
1907 
1908 	return (error);
1909 }
1910 
1911 int
1912 elfcore(vnode_t *vp, proc_t *p, cred_t *credp, rlim64_t rlimit, int sig,
1913     core_content_t content)
1914 {
1915 	offset_t poffset, soffset;
1916 	Off doffset;
1917 	int error, i, nphdrs, nshdrs;
1918 	int overflow = 0;
1919 	struct seg *seg;
1920 	struct as *as = p->p_as;
1921 	union {
1922 		Ehdr ehdr;
1923 		Phdr phdr[1];
1924 		Shdr shdr[1];
1925 	} *bigwad;
1926 	size_t bigsize;
1927 	size_t phdrsz, shdrsz;
1928 	Ehdr *ehdr;
1929 	Phdr *v;
1930 	caddr_t brkbase;
1931 	size_t brksize;
1932 	caddr_t stkbase;
1933 	size_t stksize;
1934 	int ntries = 0;
1935 	klwp_t *lwp = ttolwp(curthread);
1936 
1937 top:
1938 	/*
1939 	 * Make sure we have everything we need (registers, etc.).
1940 	 * All other lwps have already stopped and are in an orderly state.
1941 	 */
1942 	ASSERT(p == ttoproc(curthread));
1943 	prstop(0, 0);
1944 
1945 	AS_LOCK_ENTER(as, RW_WRITER);
1946 	nphdrs = prnsegs(as, 0) + 2;		/* two CORE note sections */
1947 
1948 	/*
1949 	 * Count the number of section headers we're going to need.
1950 	 */
1951 	nshdrs = 0;
1952 	if (content & (CC_CONTENT_CTF | CC_CONTENT_SYMTAB)) {
1953 		(void) process_scns(content, p, credp, NULL, NULL, NULL, 0,
1954 		    NULL, &nshdrs);
1955 	}
1956 	AS_LOCK_EXIT(as);
1957 
1958 	ASSERT(nshdrs == 0 || nshdrs > 1);
1959 
1960 	/*
1961 	 * The core file contents may required zero section headers, but if
1962 	 * we overflow the 16 bits allotted to the program header count in
1963 	 * the ELF header, we'll need that program header at index zero.
1964 	 */
1965 	if (nshdrs == 0 && nphdrs >= PN_XNUM)
1966 		nshdrs = 1;
1967 
1968 	phdrsz = nphdrs * sizeof (Phdr);
1969 	shdrsz = nshdrs * sizeof (Shdr);
1970 
1971 	bigsize = MAX(sizeof (*bigwad), MAX(phdrsz, shdrsz));
1972 	bigwad = kmem_alloc(bigsize, KM_SLEEP);
1973 
1974 	ehdr = &bigwad->ehdr;
1975 	bzero(ehdr, sizeof (*ehdr));
1976 
1977 	ehdr->e_ident[EI_MAG0] = ELFMAG0;
1978 	ehdr->e_ident[EI_MAG1] = ELFMAG1;
1979 	ehdr->e_ident[EI_MAG2] = ELFMAG2;
1980 	ehdr->e_ident[EI_MAG3] = ELFMAG3;
1981 	ehdr->e_ident[EI_CLASS] = ELFCLASS;
1982 	ehdr->e_type = ET_CORE;
1983 
1984 #if !defined(_LP64) || defined(_ELF32_COMPAT)
1985 
1986 #if defined(__sparc)
1987 	ehdr->e_ident[EI_DATA] = ELFDATA2MSB;
1988 	ehdr->e_machine = EM_SPARC;
1989 #elif defined(__i386) || defined(__i386_COMPAT)
1990 	ehdr->e_ident[EI_DATA] = ELFDATA2LSB;
1991 	ehdr->e_machine = EM_386;
1992 #else
1993 #error "no recognized machine type is defined"
1994 #endif
1995 
1996 #else	/* !defined(_LP64) || defined(_ELF32_COMPAT) */
1997 
1998 #if defined(__sparc)
1999 	ehdr->e_ident[EI_DATA] = ELFDATA2MSB;
2000 	ehdr->e_machine = EM_SPARCV9;
2001 #elif defined(__amd64)
2002 	ehdr->e_ident[EI_DATA] = ELFDATA2LSB;
2003 	ehdr->e_machine = EM_AMD64;
2004 #else
2005 #error "no recognized 64-bit machine type is defined"
2006 #endif
2007 
2008 #endif	/* !defined(_LP64) || defined(_ELF32_COMPAT) */
2009 
2010 	/*
2011 	 * If the count of program headers or section headers or the index
2012 	 * of the section string table can't fit in the mere 16 bits
2013 	 * shortsightedly allotted to them in the ELF header, we use the
2014 	 * extended formats and put the real values in the section header
2015 	 * as index 0.
2016 	 */
2017 	ehdr->e_version = EV_CURRENT;
2018 	ehdr->e_ehsize = sizeof (Ehdr);
2019 
2020 	if (nphdrs >= PN_XNUM)
2021 		ehdr->e_phnum = PN_XNUM;
2022 	else
2023 		ehdr->e_phnum = (unsigned short)nphdrs;
2024 
2025 	ehdr->e_phoff = sizeof (Ehdr);
2026 	ehdr->e_phentsize = sizeof (Phdr);
2027 
2028 	if (nshdrs > 0) {
2029 		if (nshdrs >= SHN_LORESERVE)
2030 			ehdr->e_shnum = 0;
2031 		else
2032 			ehdr->e_shnum = (unsigned short)nshdrs;
2033 
2034 		if (nshdrs - 1 >= SHN_LORESERVE)
2035 			ehdr->e_shstrndx = SHN_XINDEX;
2036 		else
2037 			ehdr->e_shstrndx = (unsigned short)(nshdrs - 1);
2038 
2039 		ehdr->e_shoff = ehdr->e_phoff + ehdr->e_phentsize * nphdrs;
2040 		ehdr->e_shentsize = sizeof (Shdr);
2041 	}
2042 
2043 	if (error = core_write(vp, UIO_SYSSPACE, (offset_t)0, ehdr,
2044 	    sizeof (Ehdr), rlimit, credp))
2045 		goto done;
2046 
2047 	poffset = sizeof (Ehdr);
2048 	soffset = sizeof (Ehdr) + phdrsz;
2049 	doffset = sizeof (Ehdr) + phdrsz + shdrsz;
2050 
2051 	v = &bigwad->phdr[0];
2052 	bzero(v, phdrsz);
2053 
2054 	setup_old_note_header(&v[0], p);
2055 	v[0].p_offset = doffset = roundup(doffset, sizeof (Word));
2056 	doffset += v[0].p_filesz;
2057 
2058 	setup_note_header(&v[1], p);
2059 	v[1].p_offset = doffset = roundup(doffset, sizeof (Word));
2060 	doffset += v[1].p_filesz;
2061 
2062 	mutex_enter(&p->p_lock);
2063 
2064 	brkbase = p->p_brkbase;
2065 	brksize = p->p_brksize;
2066 
2067 	stkbase = p->p_usrstack - p->p_stksize;
2068 	stksize = p->p_stksize;
2069 
2070 	mutex_exit(&p->p_lock);
2071 
2072 	AS_LOCK_ENTER(as, RW_WRITER);
2073 	i = 2;
2074 	for (seg = AS_SEGFIRST(as); seg != NULL; seg = AS_SEGNEXT(as, seg)) {
2075 		caddr_t eaddr = seg->s_base + pr_getsegsize(seg, 0);
2076 		caddr_t saddr, naddr;
2077 		void *tmp = NULL;
2078 		extern struct seg_ops segspt_shmops;
2079 
2080 		if ((seg->s_flags & S_HOLE) != 0) {
2081 			continue;
2082 		}
2083 
2084 		for (saddr = seg->s_base; saddr < eaddr; saddr = naddr) {
2085 			uint_t prot;
2086 			size_t size;
2087 			int type;
2088 			vnode_t *mvp;
2089 
2090 			prot = pr_getprot(seg, 0, &tmp, &saddr, &naddr, eaddr);
2091 			prot &= PROT_READ | PROT_WRITE | PROT_EXEC;
2092 			if ((size = (size_t)(naddr - saddr)) == 0)
2093 				continue;
2094 			if (i == nphdrs) {
2095 				overflow++;
2096 				continue;
2097 			}
2098 			v[i].p_type = PT_LOAD;
2099 			v[i].p_vaddr = (Addr)(uintptr_t)saddr;
2100 			v[i].p_memsz = size;
2101 			if (prot & PROT_READ)
2102 				v[i].p_flags |= PF_R;
2103 			if (prot & PROT_WRITE)
2104 				v[i].p_flags |= PF_W;
2105 			if (prot & PROT_EXEC)
2106 				v[i].p_flags |= PF_X;
2107 
2108 			/*
2109 			 * Figure out which mappings to include in the core.
2110 			 */
2111 			type = SEGOP_GETTYPE(seg, saddr);
2112 
2113 			if (saddr == stkbase && size == stksize) {
2114 				if (!(content & CC_CONTENT_STACK))
2115 					goto exclude;
2116 
2117 			} else if (saddr == brkbase && size == brksize) {
2118 				if (!(content & CC_CONTENT_HEAP))
2119 					goto exclude;
2120 
2121 			} else if (seg->s_ops == &segspt_shmops) {
2122 				if (type & MAP_NORESERVE) {
2123 					if (!(content & CC_CONTENT_DISM))
2124 						goto exclude;
2125 				} else {
2126 					if (!(content & CC_CONTENT_ISM))
2127 						goto exclude;
2128 				}
2129 
2130 			} else if (seg->s_ops != &segvn_ops) {
2131 				goto exclude;
2132 
2133 			} else if (type & MAP_SHARED) {
2134 				if (shmgetid(p, saddr) != SHMID_NONE) {
2135 					if (!(content & CC_CONTENT_SHM))
2136 						goto exclude;
2137 
2138 				} else if (SEGOP_GETVP(seg, seg->s_base,
2139 				    &mvp) != 0 || mvp == NULL ||
2140 				    mvp->v_type != VREG) {
2141 					if (!(content & CC_CONTENT_SHANON))
2142 						goto exclude;
2143 
2144 				} else {
2145 					if (!(content & CC_CONTENT_SHFILE))
2146 						goto exclude;
2147 				}
2148 
2149 			} else if (SEGOP_GETVP(seg, seg->s_base, &mvp) != 0 ||
2150 			    mvp == NULL || mvp->v_type != VREG) {
2151 				if (!(content & CC_CONTENT_ANON))
2152 					goto exclude;
2153 
2154 			} else if (prot == (PROT_READ | PROT_EXEC)) {
2155 				if (!(content & CC_CONTENT_TEXT))
2156 					goto exclude;
2157 
2158 			} else if (prot == PROT_READ) {
2159 				if (!(content & CC_CONTENT_RODATA))
2160 					goto exclude;
2161 
2162 			} else {
2163 				if (!(content & CC_CONTENT_DATA))
2164 					goto exclude;
2165 			}
2166 
2167 			doffset = roundup(doffset, sizeof (Word));
2168 			v[i].p_offset = doffset;
2169 			v[i].p_filesz = size;
2170 			doffset += size;
2171 exclude:
2172 			i++;
2173 		}
2174 		ASSERT(tmp == NULL);
2175 	}
2176 	AS_LOCK_EXIT(as);
2177 
2178 	if (overflow || i != nphdrs) {
2179 		if (ntries++ == 0) {
2180 			kmem_free(bigwad, bigsize);
2181 			overflow = 0;
2182 			goto top;
2183 		}
2184 		cmn_err(CE_WARN, "elfcore: core dump failed for "
2185 		    "process %d; address space is changing", p->p_pid);
2186 		error = EIO;
2187 		goto done;
2188 	}
2189 
2190 	if ((error = core_write(vp, UIO_SYSSPACE, poffset,
2191 	    v, phdrsz, rlimit, credp)) != 0)
2192 		goto done;
2193 
2194 	if ((error = write_old_elfnotes(p, sig, vp, v[0].p_offset, rlimit,
2195 	    credp)) != 0)
2196 		goto done;
2197 
2198 	if ((error = write_elfnotes(p, sig, vp, v[1].p_offset, rlimit,
2199 	    credp, content)) != 0)
2200 		goto done;
2201 
2202 	for (i = 2; i < nphdrs; i++) {
2203 		prkillinfo_t killinfo;
2204 		sigqueue_t *sq;
2205 		int sig, j;
2206 
2207 		if (v[i].p_filesz == 0)
2208 			continue;
2209 
2210 		/*
2211 		 * If dumping out this segment fails, rather than failing
2212 		 * the core dump entirely, we reset the size of the mapping
2213 		 * to zero to indicate that the data is absent from the core
2214 		 * file and or in the PF_SUNW_FAILURE flag to differentiate
2215 		 * this from mappings that were excluded due to the core file
2216 		 * content settings.
2217 		 */
2218 		if ((error = core_seg(p, vp, v[i].p_offset,
2219 		    (caddr_t)(uintptr_t)v[i].p_vaddr, v[i].p_filesz,
2220 		    rlimit, credp)) == 0) {
2221 			continue;
2222 		}
2223 
2224 		if ((sig = lwp->lwp_cursig) == 0) {
2225 			/*
2226 			 * We failed due to something other than a signal.
2227 			 * Since the space reserved for the segment is now
2228 			 * unused, we stash the errno in the first four
2229 			 * bytes. This undocumented interface will let us
2230 			 * understand the nature of the failure.
2231 			 */
2232 			(void) core_write(vp, UIO_SYSSPACE, v[i].p_offset,
2233 			    &error, sizeof (error), rlimit, credp);
2234 
2235 			v[i].p_filesz = 0;
2236 			v[i].p_flags |= PF_SUNW_FAILURE;
2237 			if ((error = core_write(vp, UIO_SYSSPACE,
2238 			    poffset + sizeof (v[i]) * i, &v[i], sizeof (v[i]),
2239 			    rlimit, credp)) != 0)
2240 				goto done;
2241 
2242 			continue;
2243 		}
2244 
2245 		/*
2246 		 * We took a signal.  We want to abort the dump entirely, but
2247 		 * we also want to indicate what failed and why.  We therefore
2248 		 * use the space reserved for the first failing segment to
2249 		 * write our error (which, for purposes of compatability with
2250 		 * older core dump readers, we set to EINTR) followed by any
2251 		 * siginfo associated with the signal.
2252 		 */
2253 		bzero(&killinfo, sizeof (killinfo));
2254 		killinfo.prk_error = EINTR;
2255 
2256 		sq = sig == SIGKILL ? curproc->p_killsqp : lwp->lwp_curinfo;
2257 
2258 		if (sq != NULL) {
2259 			bcopy(&sq->sq_info, &killinfo.prk_info,
2260 			    sizeof (sq->sq_info));
2261 		} else {
2262 			killinfo.prk_info.si_signo = lwp->lwp_cursig;
2263 			killinfo.prk_info.si_code = SI_NOINFO;
2264 		}
2265 
2266 #if (defined(_SYSCALL32_IMPL) || defined(_LP64))
2267 		/*
2268 		 * If this is a 32-bit process, we need to translate from the
2269 		 * native siginfo to the 32-bit variant.  (Core readers must
2270 		 * always have the same data model as their target or must
2271 		 * be aware of -- and compensate for -- data model differences.)
2272 		 */
2273 		if (curproc->p_model == DATAMODEL_ILP32) {
2274 			siginfo32_t si32;
2275 
2276 			siginfo_kto32((k_siginfo_t *)&killinfo.prk_info, &si32);
2277 			bcopy(&si32, &killinfo.prk_info, sizeof (si32));
2278 		}
2279 #endif
2280 
2281 		(void) core_write(vp, UIO_SYSSPACE, v[i].p_offset,
2282 		    &killinfo, sizeof (killinfo), rlimit, credp);
2283 
2284 		/*
2285 		 * For the segment on which we took the signal, indicate that
2286 		 * its data now refers to a siginfo.
2287 		 */
2288 		v[i].p_filesz = 0;
2289 		v[i].p_flags |= PF_SUNW_FAILURE | PF_SUNW_KILLED |
2290 		    PF_SUNW_SIGINFO;
2291 
2292 		/*
2293 		 * And for every other segment, indicate that its absence
2294 		 * is due to a signal.
2295 		 */
2296 		for (j = i + 1; j < nphdrs; j++) {
2297 			v[j].p_filesz = 0;
2298 			v[j].p_flags |= PF_SUNW_FAILURE | PF_SUNW_KILLED;
2299 		}
2300 
2301 		/*
2302 		 * Finally, write out our modified program headers.
2303 		 */
2304 		if ((error = core_write(vp, UIO_SYSSPACE,
2305 		    poffset + sizeof (v[i]) * i, &v[i],
2306 		    sizeof (v[i]) * (nphdrs - i), rlimit, credp)) != 0)
2307 			goto done;
2308 
2309 		break;
2310 	}
2311 
2312 	if (nshdrs > 0) {
2313 		bzero(&bigwad->shdr[0], shdrsz);
2314 
2315 		if (nshdrs >= SHN_LORESERVE)
2316 			bigwad->shdr[0].sh_size = nshdrs;
2317 
2318 		if (nshdrs - 1 >= SHN_LORESERVE)
2319 			bigwad->shdr[0].sh_link = nshdrs - 1;
2320 
2321 		if (nphdrs >= PN_XNUM)
2322 			bigwad->shdr[0].sh_info = nphdrs;
2323 
2324 		if (nshdrs > 1) {
2325 			AS_LOCK_ENTER(as, RW_WRITER);
2326 			if ((error = process_scns(content, p, credp, vp,
2327 			    &bigwad->shdr[0], nshdrs, rlimit, &doffset,
2328 			    NULL)) != 0) {
2329 				AS_LOCK_EXIT(as);
2330 				goto done;
2331 			}
2332 			AS_LOCK_EXIT(as);
2333 		}
2334 
2335 		if ((error = core_write(vp, UIO_SYSSPACE, soffset,
2336 		    &bigwad->shdr[0], shdrsz, rlimit, credp)) != 0)
2337 			goto done;
2338 	}
2339 
2340 done:
2341 	kmem_free(bigwad, bigsize);
2342 	return (error);
2343 }
2344 
2345 #ifndef	_ELF32_COMPAT
2346 
2347 static struct execsw esw = {
2348 #ifdef	_LP64
2349 	elf64magicstr,
2350 #else	/* _LP64 */
2351 	elf32magicstr,
2352 #endif	/* _LP64 */
2353 	0,
2354 	5,
2355 	elfexec,
2356 	elfcore
2357 };
2358 
2359 static struct modlexec modlexec = {
2360 	&mod_execops, "exec module for elf", &esw
2361 };
2362 
2363 #ifdef	_LP64
2364 extern int elf32exec(vnode_t *vp, execa_t *uap, uarg_t *args,
2365 			intpdata_t *idatap, int level, long *execsz,
2366 			int setid, caddr_t exec_file, cred_t *cred,
2367 			int brand_action);
2368 extern int elf32core(vnode_t *vp, proc_t *p, cred_t *credp,
2369 			rlim64_t rlimit, int sig, core_content_t content);
2370 
2371 static struct execsw esw32 = {
2372 	elf32magicstr,
2373 	0,
2374 	5,
2375 	elf32exec,
2376 	elf32core
2377 };
2378 
2379 static struct modlexec modlexec32 = {
2380 	&mod_execops, "32-bit exec module for elf", &esw32
2381 };
2382 #endif	/* _LP64 */
2383 
2384 static struct modlinkage modlinkage = {
2385 	MODREV_1,
2386 	(void *)&modlexec,
2387 #ifdef	_LP64
2388 	(void *)&modlexec32,
2389 #endif	/* _LP64 */
2390 	NULL
2391 };
2392 
2393 int
2394 _init(void)
2395 {
2396 	return (mod_install(&modlinkage));
2397 }
2398 
2399 int
2400 _fini(void)
2401 {
2402 	return (mod_remove(&modlinkage));
2403 }
2404 
2405 int
2406 _info(struct modinfo *modinfop)
2407 {
2408 	return (mod_info(&modlinkage, modinfop));
2409 }
2410 
2411 #endif	/* !_ELF32_COMPAT */
2412