xref: /titanic_41/usr/src/uts/common/exec/elf/elf.c (revision dd7afb26c5036958cddc0c2c1e499571664a6ed0)
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 2016 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/cmn_err.h>
46 #include <sys/systm.h>
47 #include <sys/elf.h>
48 #include <sys/vmsystm.h>
49 #include <sys/debug.h>
50 #include <sys/auxv.h>
51 #include <sys/exec.h>
52 #include <sys/prsystm.h>
53 #include <vm/as.h>
54 #include <vm/rm.h>
55 #include <vm/seg.h>
56 #include <vm/seg_vn.h>
57 #include <sys/modctl.h>
58 #include <sys/systeminfo.h>
59 #include <sys/vmparam.h>
60 #include <sys/machelf.h>
61 #include <sys/shm_impl.h>
62 #include <sys/archsystm.h>
63 #include <sys/fasttrap.h>
64 #include <sys/brand.h>
65 #include "elf_impl.h"
66 #include <sys/sdt.h>
67 #include <sys/siginfo.h>
68 
69 #if defined(__x86)
70 #include <sys/comm_page_util.h>
71 #endif /* defined(__x86) */
72 
73 
74 extern int at_flags;
75 
76 #define	ORIGIN_STR	"ORIGIN"
77 #define	ORIGIN_STR_SIZE	6
78 
79 static int getelfhead(vnode_t *, cred_t *, Ehdr *, int *, int *, int *);
80 static int getelfphdr(vnode_t *, cred_t *, const Ehdr *, int, caddr_t *,
81     ssize_t *);
82 static int getelfshdr(vnode_t *, cred_t *, const Ehdr *, int, int, caddr_t *,
83     ssize_t *, caddr_t *, ssize_t *);
84 static size_t elfsize(Ehdr *, int, caddr_t, uintptr_t *);
85 static int mapelfexec(vnode_t *, Ehdr *, int, caddr_t,
86     Phdr **, Phdr **, Phdr **, Phdr **, Phdr *,
87     caddr_t *, caddr_t *, intptr_t *, intptr_t *, size_t, long *, size_t *);
88 
89 typedef enum {
90 	STR_CTF,
91 	STR_SYMTAB,
92 	STR_DYNSYM,
93 	STR_STRTAB,
94 	STR_DYNSTR,
95 	STR_SHSTRTAB,
96 	STR_NUM
97 } shstrtype_t;
98 
99 static const char *shstrtab_data[] = {
100 	".SUNW_ctf",
101 	".symtab",
102 	".dynsym",
103 	".strtab",
104 	".dynstr",
105 	".shstrtab"
106 };
107 
108 typedef struct shstrtab {
109 	int	sst_ndx[STR_NUM];
110 	int	sst_cur;
111 } shstrtab_t;
112 
113 static void
shstrtab_init(shstrtab_t * s)114 shstrtab_init(shstrtab_t *s)
115 {
116 	bzero(&s->sst_ndx, sizeof (s->sst_ndx));
117 	s->sst_cur = 1;
118 }
119 
120 static int
shstrtab_ndx(shstrtab_t * s,shstrtype_t type)121 shstrtab_ndx(shstrtab_t *s, shstrtype_t type)
122 {
123 	int ret;
124 
125 	if ((ret = s->sst_ndx[type]) != 0)
126 		return (ret);
127 
128 	ret = s->sst_ndx[type] = s->sst_cur;
129 	s->sst_cur += strlen(shstrtab_data[type]) + 1;
130 
131 	return (ret);
132 }
133 
134 static size_t
shstrtab_size(const shstrtab_t * s)135 shstrtab_size(const shstrtab_t *s)
136 {
137 	return (s->sst_cur);
138 }
139 
140 static void
shstrtab_dump(const shstrtab_t * s,char * buf)141 shstrtab_dump(const shstrtab_t *s, char *buf)
142 {
143 	int i, ndx;
144 
145 	*buf = '\0';
146 	for (i = 0; i < STR_NUM; i++) {
147 		if ((ndx = s->sst_ndx[i]) != 0)
148 			(void) strcpy(buf + ndx, shstrtab_data[i]);
149 	}
150 }
151 
152 static int
dtrace_safe_phdr(Phdr * phdrp,struct uarg * args,uintptr_t base)153 dtrace_safe_phdr(Phdr *phdrp, struct uarg *args, uintptr_t base)
154 {
155 	ASSERT(phdrp->p_type == PT_SUNWDTRACE);
156 
157 	/*
158 	 * See the comment in fasttrap.h for information on how to safely
159 	 * update this program header.
160 	 */
161 	if (phdrp->p_memsz < PT_SUNWDTRACE_SIZE ||
162 	    (phdrp->p_flags & (PF_R | PF_W | PF_X)) != (PF_R | PF_W | PF_X))
163 		return (-1);
164 
165 	args->thrptr = phdrp->p_vaddr + base;
166 
167 	return (0);
168 }
169 
170 /*
171  * Map in the executable pointed to by vp. Returns 0 on success.
172  */
173 int
mapexec_brand(vnode_t * vp,uarg_t * args,Ehdr * ehdr,Addr * uphdr_vaddr,intptr_t * voffset,caddr_t exec_file,int * interp,caddr_t * bssbase,caddr_t * brkbase,size_t * brksize,uintptr_t * lddatap)174 mapexec_brand(vnode_t *vp, uarg_t *args, Ehdr *ehdr, Addr *uphdr_vaddr,
175     intptr_t *voffset, caddr_t exec_file, int *interp, caddr_t *bssbase,
176     caddr_t *brkbase, size_t *brksize, uintptr_t *lddatap)
177 {
178 	size_t		len;
179 	struct vattr	vat;
180 	caddr_t		phdrbase = NULL;
181 	ssize_t		phdrsize;
182 	int		nshdrs, shstrndx, nphdrs;
183 	int		error = 0;
184 	Phdr		*uphdr = NULL;
185 	Phdr		*junk = NULL;
186 	Phdr		*dynphdr = NULL;
187 	Phdr		*dtrphdr = NULL;
188 	uintptr_t	lddata;
189 	long		execsz;
190 	intptr_t	minaddr;
191 
192 	if (lddatap != NULL)
193 		*lddatap = NULL;
194 
195 	if (error = execpermissions(vp, &vat, args)) {
196 		uprintf("%s: Cannot execute %s\n", exec_file, args->pathname);
197 		return (error);
198 	}
199 
200 	if ((error = getelfhead(vp, CRED(), ehdr, &nshdrs, &shstrndx,
201 	    &nphdrs)) != 0 ||
202 	    (error = getelfphdr(vp, CRED(), ehdr, nphdrs, &phdrbase,
203 	    &phdrsize)) != 0) {
204 		uprintf("%s: Cannot read %s\n", exec_file, args->pathname);
205 		return (error);
206 	}
207 
208 	if ((len = elfsize(ehdr, nphdrs, phdrbase, &lddata)) == 0) {
209 		uprintf("%s: Nothing to load in %s", exec_file, args->pathname);
210 		kmem_free(phdrbase, phdrsize);
211 		return (ENOEXEC);
212 	}
213 	if (lddatap != NULL)
214 		*lddatap = lddata;
215 
216 	if (error = mapelfexec(vp, ehdr, nphdrs, phdrbase, &uphdr, &dynphdr,
217 	    &junk, &dtrphdr, NULL, bssbase, brkbase, voffset, &minaddr,
218 	    len, &execsz, brksize)) {
219 		uprintf("%s: Cannot map %s\n", exec_file, args->pathname);
220 		kmem_free(phdrbase, phdrsize);
221 		return (error);
222 	}
223 
224 	/*
225 	 * Inform our caller if the executable needs an interpreter.
226 	 */
227 	*interp = (dynphdr == NULL) ? 0 : 1;
228 
229 	/*
230 	 * If this is a statically linked executable, voffset should indicate
231 	 * the address of the executable itself (it normally holds the address
232 	 * of the interpreter).
233 	 */
234 	if (ehdr->e_type == ET_EXEC && *interp == 0)
235 		*voffset = minaddr;
236 
237 	if (uphdr != NULL) {
238 		*uphdr_vaddr = uphdr->p_vaddr;
239 	} else {
240 		*uphdr_vaddr = (Addr)-1;
241 	}
242 
243 	kmem_free(phdrbase, phdrsize);
244 	return (error);
245 }
246 
247 /*ARGSUSED*/
248 int
elfexec(vnode_t * vp,execa_t * uap,uarg_t * args,intpdata_t * idatap,int level,long * execsz,int setid,caddr_t exec_file,cred_t * cred,int brand_action)249 elfexec(vnode_t *vp, execa_t *uap, uarg_t *args, intpdata_t *idatap,
250     int level, long *execsz, int setid, caddr_t exec_file, cred_t *cred,
251     int brand_action)
252 {
253 	caddr_t		phdrbase = NULL;
254 	caddr_t 	bssbase = 0;
255 	caddr_t 	brkbase = 0;
256 	size_t		brksize = 0;
257 	ssize_t		dlnsize;
258 	aux_entry_t	*aux;
259 	int		error;
260 	ssize_t		resid;
261 	int		fd = -1;
262 	intptr_t	voffset;
263 	Phdr		*dyphdr = NULL;
264 	Phdr		*stphdr = NULL;
265 	Phdr		*uphdr = NULL;
266 	Phdr		*junk = NULL;
267 	size_t		len;
268 	ssize_t		phdrsize;
269 	int		postfixsize = 0;
270 	int		i, hsize;
271 	Phdr		*phdrp;
272 	Phdr		*dataphdrp = NULL;
273 	Phdr		*dtrphdr;
274 	Phdr		*capphdr = NULL;
275 	Cap		*cap = NULL;
276 	ssize_t		capsize;
277 	int		hasu = 0;
278 	int		hasauxv = 0;
279 	int		hasdy = 0;
280 	int		branded = 0;
281 
282 	struct proc *p = ttoproc(curthread);
283 	struct user *up = PTOU(p);
284 	struct bigwad {
285 		Ehdr	ehdr;
286 		aux_entry_t	elfargs[__KERN_NAUXV_IMPL];
287 		char		dl_name[MAXPATHLEN];
288 		char		pathbuf[MAXPATHLEN];
289 		struct vattr	vattr;
290 		struct execenv	exenv;
291 	} *bigwad;	/* kmem_alloc this behemoth so we don't blow stack */
292 	Ehdr		*ehdrp;
293 	int		nshdrs, shstrndx, nphdrs;
294 	char		*dlnp;
295 	char		*pathbufp;
296 	rlim64_t	limit;
297 	rlim64_t	roundlimit;
298 
299 	ASSERT(p->p_model == DATAMODEL_ILP32 || p->p_model == DATAMODEL_LP64);
300 
301 	bigwad = kmem_alloc(sizeof (struct bigwad), KM_SLEEP);
302 	ehdrp = &bigwad->ehdr;
303 	dlnp = bigwad->dl_name;
304 	pathbufp = bigwad->pathbuf;
305 
306 	/*
307 	 * Obtain ELF and program header information.
308 	 */
309 	if ((error = getelfhead(vp, CRED(), ehdrp, &nshdrs, &shstrndx,
310 	    &nphdrs)) != 0 ||
311 	    (error = getelfphdr(vp, CRED(), ehdrp, nphdrs, &phdrbase,
312 	    &phdrsize)) != 0)
313 		goto out;
314 
315 	/*
316 	 * Prevent executing an ELF file that has no entry point.
317 	 */
318 	if (ehdrp->e_entry == 0) {
319 		uprintf("%s: Bad entry point\n", exec_file);
320 		goto bad;
321 	}
322 
323 	/*
324 	 * Put data model that we're exec-ing to into the args passed to
325 	 * exec_args(), so it will know what it is copying to on new stack.
326 	 * Now that we know whether we are exec-ing a 32-bit or 64-bit
327 	 * executable, we can set execsz with the appropriate NCARGS.
328 	 */
329 #ifdef	_LP64
330 	if (ehdrp->e_ident[EI_CLASS] == ELFCLASS32) {
331 		args->to_model = DATAMODEL_ILP32;
332 		*execsz = btopr(SINCR) + btopr(SSIZE) + btopr(NCARGS32-1);
333 	} else {
334 		args->to_model = DATAMODEL_LP64;
335 		args->stk_prot &= ~PROT_EXEC;
336 #if defined(__i386) || defined(__amd64)
337 		args->dat_prot &= ~PROT_EXEC;
338 #endif
339 		*execsz = btopr(SINCR) + btopr(SSIZE) + btopr(NCARGS64-1);
340 	}
341 #else	/* _LP64 */
342 	args->to_model = DATAMODEL_ILP32;
343 	*execsz = btopr(SINCR) + btopr(SSIZE) + btopr(NCARGS-1);
344 #endif	/* _LP64 */
345 
346 	/*
347 	 * We delay invoking the brand callback until we've figured out
348 	 * what kind of elf binary we're trying to run, 32-bit or 64-bit.
349 	 * We do this because now the brand library can just check
350 	 * args->to_model to see if the target is 32-bit or 64-bit without
351 	 * having do duplicate all the code above.
352 	 */
353 	if ((level < 2) &&
354 	    (brand_action != EBA_NATIVE) && (PROC_IS_BRANDED(p))) {
355 		error = BROP(p)->b_elfexec(vp, uap, args,
356 		    idatap, level + 1, execsz, setid, exec_file, cred,
357 		    brand_action);
358 		goto out;
359 	}
360 
361 	/*
362 	 * Determine aux size now so that stack can be built
363 	 * in one shot (except actual copyout of aux image),
364 	 * determine any non-default stack protections,
365 	 * and still have this code be machine independent.
366 	 */
367 	hsize = ehdrp->e_phentsize;
368 	phdrp = (Phdr *)phdrbase;
369 	for (i = nphdrs; i > 0; i--) {
370 		switch (phdrp->p_type) {
371 		case PT_INTERP:
372 			hasauxv = hasdy = 1;
373 			break;
374 		case PT_PHDR:
375 			hasu = 1;
376 			break;
377 		case PT_SUNWSTACK:
378 			args->stk_prot = PROT_USER;
379 			if (phdrp->p_flags & PF_R)
380 				args->stk_prot |= PROT_READ;
381 			if (phdrp->p_flags & PF_W)
382 				args->stk_prot |= PROT_WRITE;
383 			if (phdrp->p_flags & PF_X)
384 				args->stk_prot |= PROT_EXEC;
385 			break;
386 		case PT_LOAD:
387 			dataphdrp = phdrp;
388 			break;
389 		case PT_SUNWCAP:
390 			capphdr = phdrp;
391 			break;
392 		}
393 		phdrp = (Phdr *)((caddr_t)phdrp + hsize);
394 	}
395 
396 	if (ehdrp->e_type != ET_EXEC) {
397 		dataphdrp = NULL;
398 		hasauxv = 1;
399 	}
400 
401 	/* Copy BSS permissions to args->dat_prot */
402 	if (dataphdrp != NULL) {
403 		args->dat_prot = PROT_USER;
404 		if (dataphdrp->p_flags & PF_R)
405 			args->dat_prot |= PROT_READ;
406 		if (dataphdrp->p_flags & PF_W)
407 			args->dat_prot |= PROT_WRITE;
408 		if (dataphdrp->p_flags & PF_X)
409 			args->dat_prot |= PROT_EXEC;
410 	}
411 
412 	/*
413 	 * If a auxvector will be required - reserve the space for
414 	 * it now.  This may be increased by exec_args if there are
415 	 * ISA-specific types (included in __KERN_NAUXV_IMPL).
416 	 */
417 	if (hasauxv) {
418 		/*
419 		 * If a AUX vector is being built - the base AUX
420 		 * entries are:
421 		 *
422 		 *	AT_BASE
423 		 *	AT_FLAGS
424 		 *	AT_PAGESZ
425 		 *	AT_SUN_AUXFLAGS
426 		 *	AT_SUN_HWCAP
427 		 *	AT_SUN_HWCAP2
428 		 *	AT_SUN_PLATFORM (added in stk_copyout)
429 		 *	AT_SUN_EXECNAME (added in stk_copyout)
430 		 *	AT_NULL
431 		 *
432 		 * total == 9
433 		 */
434 		if (hasdy && hasu) {
435 			/*
436 			 * Has PT_INTERP & PT_PHDR - the auxvectors that
437 			 * will be built are:
438 			 *
439 			 *	AT_PHDR
440 			 *	AT_PHENT
441 			 *	AT_PHNUM
442 			 *	AT_ENTRY
443 			 *	AT_LDDATA
444 			 *
445 			 * total = 5
446 			 */
447 			args->auxsize = (9 + 5) * sizeof (aux_entry_t);
448 		} else if (hasdy) {
449 			/*
450 			 * Has PT_INTERP but no PT_PHDR
451 			 *
452 			 *	AT_EXECFD
453 			 *	AT_LDDATA
454 			 *
455 			 * total = 2
456 			 */
457 			args->auxsize = (9 + 2) * sizeof (aux_entry_t);
458 		} else {
459 			args->auxsize = 9 * sizeof (aux_entry_t);
460 		}
461 	} else {
462 		args->auxsize = 0;
463 	}
464 
465 	/*
466 	 * If this binary is using an emulator, we need to add an
467 	 * AT_SUN_EMULATOR aux entry.
468 	 */
469 	if (args->emulator != NULL)
470 		args->auxsize += sizeof (aux_entry_t);
471 
472 	/*
473 	 * On supported kernels (x86_64) make room in the auxv for the
474 	 * AT_SUN_COMMPAGE entry.  This will go unpopulated on i86xpv systems
475 	 * which do not provide such functionality.
476 	 */
477 #if defined(__amd64)
478 	args->auxsize += sizeof (aux_entry_t);
479 #endif /* defined(__amd64) */
480 
481 	if ((brand_action != EBA_NATIVE) && (PROC_IS_BRANDED(p))) {
482 		branded = 1;
483 		/*
484 		 * We will be adding 4 entries to the aux vectors.  One for
485 		 * the the brandname and 3 for the brand specific aux vectors.
486 		 */
487 		args->auxsize += 4 * sizeof (aux_entry_t);
488 	}
489 
490 	/* Hardware/Software capabilities */
491 	if (capphdr != NULL &&
492 	    (capsize = capphdr->p_filesz) > 0 &&
493 	    capsize <= 16 * sizeof (*cap)) {
494 		int ncaps = capsize / sizeof (*cap);
495 		Cap *cp;
496 
497 		cap = kmem_alloc(capsize, KM_SLEEP);
498 		if ((error = vn_rdwr(UIO_READ, vp, (caddr_t)cap,
499 		    capsize, (offset_t)capphdr->p_offset,
500 		    UIO_SYSSPACE, 0, (rlim64_t)0, CRED(), &resid)) != 0) {
501 			uprintf("%s: Cannot read capabilities section\n",
502 			    exec_file);
503 			goto out;
504 		}
505 		for (cp = cap; cp < cap + ncaps; cp++) {
506 			if (cp->c_tag == CA_SUNW_SF_1 &&
507 			    (cp->c_un.c_val & SF1_SUNW_ADDR32)) {
508 				if (args->to_model == DATAMODEL_LP64)
509 					args->addr32 = 1;
510 				break;
511 			}
512 		}
513 	}
514 
515 	aux = bigwad->elfargs;
516 	/*
517 	 * Move args to the user's stack.
518 	 * This can fill in the AT_SUN_PLATFORM and AT_SUN_EXECNAME aux entries.
519 	 */
520 	if ((error = exec_args(uap, args, idatap, (void **)&aux)) != 0) {
521 		if (error == -1) {
522 			error = ENOEXEC;
523 			goto bad;
524 		}
525 		goto out;
526 	}
527 	/* we're single threaded after this point */
528 
529 	/*
530 	 * If this is an ET_DYN executable (shared object),
531 	 * determine its memory size so that mapelfexec() can load it.
532 	 */
533 	if (ehdrp->e_type == ET_DYN)
534 		len = elfsize(ehdrp, nphdrs, phdrbase, NULL);
535 	else
536 		len = 0;
537 
538 	dtrphdr = NULL;
539 
540 	if ((error = mapelfexec(vp, ehdrp, nphdrs, phdrbase, &uphdr, &dyphdr,
541 	    &stphdr, &dtrphdr, dataphdrp, &bssbase, &brkbase, &voffset, NULL,
542 	    len, execsz, &brksize)) != 0)
543 		goto bad;
544 
545 	if (uphdr != NULL && dyphdr == NULL)
546 		goto bad;
547 
548 	if (dtrphdr != NULL && dtrace_safe_phdr(dtrphdr, args, voffset) != 0) {
549 		uprintf("%s: Bad DTrace phdr in %s\n", exec_file, exec_file);
550 		goto bad;
551 	}
552 
553 	if (dyphdr != NULL) {
554 		size_t		len;
555 		uintptr_t	lddata;
556 		char		*p;
557 		struct vnode	*nvp;
558 
559 		dlnsize = dyphdr->p_filesz;
560 
561 		if (dlnsize > MAXPATHLEN || dlnsize <= 0)
562 			goto bad;
563 
564 		/*
565 		 * Read in "interpreter" pathname.
566 		 */
567 		if ((error = vn_rdwr(UIO_READ, vp, dlnp, dyphdr->p_filesz,
568 		    (offset_t)dyphdr->p_offset, UIO_SYSSPACE, 0, (rlim64_t)0,
569 		    CRED(), &resid)) != 0) {
570 			uprintf("%s: Cannot obtain interpreter pathname\n",
571 			    exec_file);
572 			goto bad;
573 		}
574 
575 		if (resid != 0 || dlnp[dlnsize - 1] != '\0')
576 			goto bad;
577 
578 		/*
579 		 * Search for '$ORIGIN' token in interpreter path.
580 		 * If found, expand it.
581 		 */
582 		for (p = dlnp; p = strchr(p, '$'); ) {
583 			uint_t	len, curlen;
584 			char	*_ptr;
585 
586 			if (strncmp(++p, ORIGIN_STR, ORIGIN_STR_SIZE))
587 				continue;
588 
589 			curlen = 0;
590 			len = p - dlnp - 1;
591 			if (len) {
592 				bcopy(dlnp, pathbufp, len);
593 				curlen += len;
594 			}
595 			if (_ptr = strrchr(args->pathname, '/')) {
596 				len = _ptr - args->pathname;
597 				if ((curlen + len) > MAXPATHLEN)
598 					break;
599 
600 				bcopy(args->pathname, &pathbufp[curlen], len);
601 				curlen += len;
602 			} else {
603 				/*
604 				 * executable is a basename found in the
605 				 * current directory.  So - just substitue
606 				 * '.' for ORIGIN.
607 				 */
608 				pathbufp[curlen] = '.';
609 				curlen++;
610 			}
611 			p += ORIGIN_STR_SIZE;
612 			len = strlen(p);
613 
614 			if ((curlen + len) > MAXPATHLEN)
615 				break;
616 			bcopy(p, &pathbufp[curlen], len);
617 			curlen += len;
618 			pathbufp[curlen++] = '\0';
619 			bcopy(pathbufp, dlnp, curlen);
620 		}
621 
622 		/*
623 		 * /usr/lib/ld.so.1 is known to be a symlink to /lib/ld.so.1
624 		 * (and /usr/lib/64/ld.so.1 is a symlink to /lib/64/ld.so.1).
625 		 * Just in case /usr is not mounted, change it now.
626 		 */
627 		if (strcmp(dlnp, USR_LIB_RTLD) == 0)
628 			dlnp += 4;
629 		error = lookupname(dlnp, UIO_SYSSPACE, FOLLOW, NULLVPP, &nvp);
630 		if (error && dlnp != bigwad->dl_name) {
631 			/* new kernel, old user-level */
632 			error = lookupname(dlnp -= 4, UIO_SYSSPACE, FOLLOW,
633 			    NULLVPP, &nvp);
634 		}
635 		if (error) {
636 			uprintf("%s: Cannot find %s\n", exec_file, dlnp);
637 			goto bad;
638 		}
639 
640 		/*
641 		 * Setup the "aux" vector.
642 		 */
643 		if (uphdr) {
644 			if (ehdrp->e_type == ET_DYN) {
645 				/* don't use the first page */
646 				bigwad->exenv.ex_brkbase = (caddr_t)PAGESIZE;
647 				bigwad->exenv.ex_bssbase = (caddr_t)PAGESIZE;
648 			} else {
649 				bigwad->exenv.ex_bssbase = bssbase;
650 				bigwad->exenv.ex_brkbase = brkbase;
651 			}
652 			bigwad->exenv.ex_brksize = brksize;
653 			bigwad->exenv.ex_magic = elfmagic;
654 			bigwad->exenv.ex_vp = vp;
655 			setexecenv(&bigwad->exenv);
656 
657 			ADDAUX(aux, AT_PHDR, uphdr->p_vaddr + voffset)
658 			ADDAUX(aux, AT_PHENT, ehdrp->e_phentsize)
659 			ADDAUX(aux, AT_PHNUM, nphdrs)
660 			ADDAUX(aux, AT_ENTRY, ehdrp->e_entry + voffset)
661 		} else {
662 			if ((error = execopen(&vp, &fd)) != 0) {
663 				VN_RELE(nvp);
664 				goto bad;
665 			}
666 
667 			ADDAUX(aux, AT_EXECFD, fd)
668 		}
669 
670 		if ((error = execpermissions(nvp, &bigwad->vattr, args)) != 0) {
671 			VN_RELE(nvp);
672 			uprintf("%s: Cannot execute %s\n", exec_file, dlnp);
673 			goto bad;
674 		}
675 
676 		/*
677 		 * Now obtain the ELF header along with the entire program
678 		 * header contained in "nvp".
679 		 */
680 		kmem_free(phdrbase, phdrsize);
681 		phdrbase = NULL;
682 		if ((error = getelfhead(nvp, CRED(), ehdrp, &nshdrs,
683 		    &shstrndx, &nphdrs)) != 0 ||
684 		    (error = getelfphdr(nvp, CRED(), ehdrp, nphdrs, &phdrbase,
685 		    &phdrsize)) != 0) {
686 			VN_RELE(nvp);
687 			uprintf("%s: Cannot read %s\n", exec_file, dlnp);
688 			goto bad;
689 		}
690 
691 		/*
692 		 * Determine memory size of the "interpreter's" loadable
693 		 * sections.  This size is then used to obtain the virtual
694 		 * address of a hole, in the user's address space, large
695 		 * enough to map the "interpreter".
696 		 */
697 		if ((len = elfsize(ehdrp, nphdrs, phdrbase, &lddata)) == 0) {
698 			VN_RELE(nvp);
699 			uprintf("%s: Nothing to load in %s\n", exec_file, dlnp);
700 			goto bad;
701 		}
702 
703 		dtrphdr = NULL;
704 
705 		error = mapelfexec(nvp, ehdrp, nphdrs, phdrbase, &junk, &junk,
706 		    &junk, &dtrphdr, NULL, NULL, NULL, &voffset, NULL, len,
707 		    execsz, NULL);
708 		if (error || junk != NULL) {
709 			VN_RELE(nvp);
710 			uprintf("%s: Cannot map %s\n", exec_file, dlnp);
711 			goto bad;
712 		}
713 
714 		/*
715 		 * We use the DTrace program header to initialize the
716 		 * architecture-specific user per-LWP location. The dtrace
717 		 * fasttrap provider requires ready access to per-LWP scratch
718 		 * space. We assume that there is only one such program header
719 		 * in the interpreter.
720 		 */
721 		if (dtrphdr != NULL &&
722 		    dtrace_safe_phdr(dtrphdr, args, voffset) != 0) {
723 			VN_RELE(nvp);
724 			uprintf("%s: Bad DTrace phdr in %s\n", exec_file, dlnp);
725 			goto bad;
726 		}
727 
728 		VN_RELE(nvp);
729 		ADDAUX(aux, AT_SUN_LDDATA, voffset + lddata)
730 	}
731 
732 	if (hasauxv) {
733 		int auxf = AF_SUN_HWCAPVERIFY;
734 
735 		/*
736 		 * Note: AT_SUN_PLATFORM and AT_SUN_EXECNAME were filled in via
737 		 * exec_args()
738 		 */
739 		ADDAUX(aux, AT_BASE, voffset)
740 		ADDAUX(aux, AT_FLAGS, at_flags)
741 		ADDAUX(aux, AT_PAGESZ, PAGESIZE)
742 		/*
743 		 * Linker flags. (security)
744 		 * p_flag not yet set at this time.
745 		 * We rely on gexec() to provide us with the information.
746 		 * If the application is set-uid but this is not reflected
747 		 * in a mismatch between real/effective uids/gids, then
748 		 * don't treat this as a set-uid exec.  So we care about
749 		 * the EXECSETID_UGIDS flag but not the ...SETID flag.
750 		 */
751 		if ((setid &= ~EXECSETID_SETID) != 0)
752 			auxf |= AF_SUN_SETUGID;
753 
754 		/*
755 		 * If we're running a native process from within a branded
756 		 * zone under pfexec then we clear the AF_SUN_SETUGID flag so
757 		 * that the native ld.so.1 is able to link with the native
758 		 * libraries instead of using the brand libraries that are
759 		 * installed in the zone.  We only do this for processes
760 		 * which we trust because we see they are already running
761 		 * under pfexec (where uid != euid).  This prevents a
762 		 * malicious user within the zone from crafting a wrapper to
763 		 * run native suid commands with unsecure libraries interposed.
764 		 */
765 		if ((brand_action == EBA_NATIVE) && (PROC_IS_BRANDED(p) &&
766 		    (setid &= ~EXECSETID_SETID) != 0))
767 			auxf &= ~AF_SUN_SETUGID;
768 
769 		/*
770 		 * Record the user addr of the auxflags aux vector entry
771 		 * since brands may optionally want to manipulate this field.
772 		 */
773 		args->auxp_auxflags =
774 		    (char *)((char *)args->stackend +
775 		    ((char *)&aux->a_type -
776 		    (char *)bigwad->elfargs));
777 		ADDAUX(aux, AT_SUN_AUXFLAGS, auxf);
778 		/*
779 		 * Hardware capability flag word (performance hints)
780 		 * Used for choosing faster library routines.
781 		 * (Potentially different between 32-bit and 64-bit ABIs)
782 		 */
783 #if defined(_LP64)
784 		if (args->to_model == DATAMODEL_NATIVE) {
785 			ADDAUX(aux, AT_SUN_HWCAP, auxv_hwcap)
786 			ADDAUX(aux, AT_SUN_HWCAP2, auxv_hwcap_2)
787 		} else {
788 			ADDAUX(aux, AT_SUN_HWCAP, auxv_hwcap32)
789 			ADDAUX(aux, AT_SUN_HWCAP2, auxv_hwcap32_2)
790 		}
791 #else
792 		ADDAUX(aux, AT_SUN_HWCAP, auxv_hwcap)
793 		ADDAUX(aux, AT_SUN_HWCAP2, auxv_hwcap_2)
794 #endif
795 		if (branded) {
796 			/*
797 			 * Reserve space for the brand-private aux vectors,
798 			 * and record the user addr of that space.
799 			 */
800 			args->auxp_brand =
801 			    (char *)((char *)args->stackend +
802 			    ((char *)&aux->a_type -
803 			    (char *)bigwad->elfargs));
804 			ADDAUX(aux, AT_SUN_BRAND_AUX1, 0)
805 			ADDAUX(aux, AT_SUN_BRAND_AUX2, 0)
806 			ADDAUX(aux, AT_SUN_BRAND_AUX3, 0)
807 		}
808 
809 		/*
810 		 * Add the comm page auxv entry, mapping it in if needed.
811 		 */
812 #if defined(__amd64)
813 		if (args->commpage != NULL ||
814 		    (args->commpage = (uintptr_t)comm_page_mapin()) != NULL) {
815 			ADDAUX(aux, AT_SUN_COMMPAGE, args->commpage)
816 		} else {
817 			/*
818 			 * If the comm page cannot be mapped, pad out the auxv
819 			 * to satisfy later size checks.
820 			 */
821 			ADDAUX(aux, AT_NULL, 0)
822 		}
823 #endif /* defined(__amd64) */
824 
825 		ADDAUX(aux, AT_NULL, 0)
826 		postfixsize = (char *)aux - (char *)bigwad->elfargs;
827 
828 		/*
829 		 * We make assumptions above when we determine how many aux
830 		 * vector entries we will be adding. However, if we have an
831 		 * invalid elf file, it is possible that mapelfexec might
832 		 * behave differently (but not return an error), in which case
833 		 * the number of aux entries we actually add will be different.
834 		 * We detect that now and error out.
835 		 */
836 		if (postfixsize != args->auxsize) {
837 			DTRACE_PROBE2(elfexec_badaux, int, postfixsize,
838 			    int, args->auxsize);
839 			goto bad;
840 		}
841 		ASSERT(postfixsize <= __KERN_NAUXV_IMPL * sizeof (aux_entry_t));
842 	}
843 
844 	/*
845 	 * For the 64-bit kernel, the limit is big enough that rounding it up
846 	 * to a page can overflow the 64-bit limit, so we check for btopr()
847 	 * overflowing here by comparing it with the unrounded limit in pages.
848 	 * If it hasn't overflowed, compare the exec size with the rounded up
849 	 * limit in pages.  Otherwise, just compare with the unrounded limit.
850 	 */
851 	limit = btop(p->p_vmem_ctl);
852 	roundlimit = btopr(p->p_vmem_ctl);
853 	if ((roundlimit > limit && *execsz > roundlimit) ||
854 	    (roundlimit < limit && *execsz > limit)) {
855 		mutex_enter(&p->p_lock);
856 		(void) rctl_action(rctlproc_legacy[RLIMIT_VMEM], p->p_rctls, p,
857 		    RCA_SAFE);
858 		mutex_exit(&p->p_lock);
859 		error = ENOMEM;
860 		goto bad;
861 	}
862 
863 	bzero(up->u_auxv, sizeof (up->u_auxv));
864 	up->u_commpagep = args->commpage;
865 	if (postfixsize) {
866 		int num_auxv;
867 
868 		/*
869 		 * Copy the aux vector to the user stack.
870 		 */
871 		error = execpoststack(args, bigwad->elfargs, postfixsize);
872 		if (error)
873 			goto bad;
874 
875 		/*
876 		 * Copy auxv to the process's user structure for use by /proc.
877 		 * If this is a branded process, the brand's exec routine will
878 		 * copy it's private entries to the user structure later. It
879 		 * relies on the fact that the blank entries are at the end.
880 		 */
881 		num_auxv = postfixsize / sizeof (aux_entry_t);
882 		ASSERT(num_auxv <= sizeof (up->u_auxv) / sizeof (auxv_t));
883 		aux = bigwad->elfargs;
884 		for (i = 0; i < num_auxv; i++) {
885 			up->u_auxv[i].a_type = aux[i].a_type;
886 			up->u_auxv[i].a_un.a_val = (aux_val_t)aux[i].a_un.a_val;
887 		}
888 	}
889 
890 	/*
891 	 * Pass back the starting address so we can set the program counter.
892 	 */
893 	args->entry = (uintptr_t)(ehdrp->e_entry + voffset);
894 
895 	if (!uphdr) {
896 		if (ehdrp->e_type == ET_DYN) {
897 			/*
898 			 * If we are executing a shared library which doesn't
899 			 * have a interpreter (probably ld.so.1) then
900 			 * we don't set the brkbase now.  Instead we
901 			 * delay it's setting until the first call
902 			 * via grow.c::brk().  This permits ld.so.1 to
903 			 * initialize brkbase to the tail of the executable it
904 			 * loads (which is where it needs to be).
905 			 */
906 			bigwad->exenv.ex_brkbase = (caddr_t)0;
907 			bigwad->exenv.ex_bssbase = (caddr_t)0;
908 			bigwad->exenv.ex_brksize = 0;
909 		} else {
910 			bigwad->exenv.ex_brkbase = brkbase;
911 			bigwad->exenv.ex_bssbase = bssbase;
912 			bigwad->exenv.ex_brksize = brksize;
913 		}
914 		bigwad->exenv.ex_magic = elfmagic;
915 		bigwad->exenv.ex_vp = vp;
916 		setexecenv(&bigwad->exenv);
917 	}
918 
919 	ASSERT(error == 0);
920 	goto out;
921 
922 bad:
923 	if (fd != -1)		/* did we open the a.out yet */
924 		(void) execclose(fd);
925 
926 	psignal(p, SIGKILL);
927 
928 	if (error == 0)
929 		error = ENOEXEC;
930 out:
931 	if (phdrbase != NULL)
932 		kmem_free(phdrbase, phdrsize);
933 	if (cap != NULL)
934 		kmem_free(cap, capsize);
935 	kmem_free(bigwad, sizeof (struct bigwad));
936 	return (error);
937 }
938 
939 /*
940  * Compute the memory size requirement for the ELF file.
941  */
942 static size_t
elfsize(Ehdr * ehdrp,int nphdrs,caddr_t phdrbase,uintptr_t * lddata)943 elfsize(Ehdr *ehdrp, int nphdrs, caddr_t phdrbase, uintptr_t *lddata)
944 {
945 	size_t	len;
946 	Phdr	*phdrp = (Phdr *)phdrbase;
947 	int	hsize = ehdrp->e_phentsize;
948 	int	first = 1;
949 	int	dfirst = 1;	/* first data segment */
950 	uintptr_t loaddr = 0;
951 	uintptr_t hiaddr = 0;
952 	uintptr_t lo, hi;
953 	int	i;
954 
955 	for (i = nphdrs; i > 0; i--) {
956 		if (phdrp->p_type == PT_LOAD) {
957 			lo = phdrp->p_vaddr;
958 			hi = lo + phdrp->p_memsz;
959 			if (first) {
960 				loaddr = lo;
961 				hiaddr = hi;
962 				first = 0;
963 			} else {
964 				if (loaddr > lo)
965 					loaddr = lo;
966 				if (hiaddr < hi)
967 					hiaddr = hi;
968 			}
969 
970 			/*
971 			 * save the address of the first data segment
972 			 * of a object - used for the AT_SUNW_LDDATA
973 			 * aux entry.
974 			 */
975 			if ((lddata != NULL) && dfirst &&
976 			    (phdrp->p_flags & PF_W)) {
977 				*lddata = lo;
978 				dfirst = 0;
979 			}
980 		}
981 		phdrp = (Phdr *)((caddr_t)phdrp + hsize);
982 	}
983 
984 	len = hiaddr - (loaddr & PAGEMASK);
985 	len = roundup(len, PAGESIZE);
986 
987 	return (len);
988 }
989 
990 /*
991  * Read in the ELF header and program header table.
992  * SUSV3 requires:
993  *	ENOEXEC	File format is not recognized
994  *	EINVAL	Format recognized but execution not supported
995  */
996 static int
getelfhead(vnode_t * vp,cred_t * credp,Ehdr * ehdr,int * nshdrs,int * shstrndx,int * nphdrs)997 getelfhead(vnode_t *vp, cred_t *credp, Ehdr *ehdr, int *nshdrs, int *shstrndx,
998     int *nphdrs)
999 {
1000 	int error;
1001 	ssize_t resid;
1002 
1003 	/*
1004 	 * We got here by the first two bytes in ident,
1005 	 * now read the entire ELF header.
1006 	 */
1007 	if ((error = vn_rdwr(UIO_READ, vp, (caddr_t)ehdr,
1008 	    sizeof (Ehdr), (offset_t)0, UIO_SYSSPACE, 0,
1009 	    (rlim64_t)0, credp, &resid)) != 0)
1010 		return (error);
1011 
1012 	/*
1013 	 * Since a separate version is compiled for handling 32-bit and
1014 	 * 64-bit ELF executables on a 64-bit kernel, the 64-bit version
1015 	 * doesn't need to be able to deal with 32-bit ELF files.
1016 	 */
1017 	if (resid != 0 ||
1018 	    ehdr->e_ident[EI_MAG2] != ELFMAG2 ||
1019 	    ehdr->e_ident[EI_MAG3] != ELFMAG3)
1020 		return (ENOEXEC);
1021 
1022 	if ((ehdr->e_type != ET_EXEC && ehdr->e_type != ET_DYN) ||
1023 #if defined(_ILP32) || defined(_ELF32_COMPAT)
1024 	    ehdr->e_ident[EI_CLASS] != ELFCLASS32 ||
1025 #else
1026 	    ehdr->e_ident[EI_CLASS] != ELFCLASS64 ||
1027 #endif
1028 	    !elfheadcheck(ehdr->e_ident[EI_DATA], ehdr->e_machine,
1029 	    ehdr->e_flags))
1030 		return (EINVAL);
1031 
1032 	*nshdrs = ehdr->e_shnum;
1033 	*shstrndx = ehdr->e_shstrndx;
1034 	*nphdrs = ehdr->e_phnum;
1035 
1036 	/*
1037 	 * If e_shnum, e_shstrndx, or e_phnum is its sentinel value, we need
1038 	 * to read in the section header at index zero to acces the true
1039 	 * values for those fields.
1040 	 */
1041 	if ((*nshdrs == 0 && ehdr->e_shoff != 0) ||
1042 	    *shstrndx == SHN_XINDEX || *nphdrs == PN_XNUM) {
1043 		Shdr shdr;
1044 
1045 		if (ehdr->e_shoff == 0)
1046 			return (EINVAL);
1047 
1048 		if ((error = vn_rdwr(UIO_READ, vp, (caddr_t)&shdr,
1049 		    sizeof (shdr), (offset_t)ehdr->e_shoff, UIO_SYSSPACE, 0,
1050 		    (rlim64_t)0, credp, &resid)) != 0)
1051 			return (error);
1052 
1053 		if (*nshdrs == 0)
1054 			*nshdrs = shdr.sh_size;
1055 		if (*shstrndx == SHN_XINDEX)
1056 			*shstrndx = shdr.sh_link;
1057 		if (*nphdrs == PN_XNUM && shdr.sh_info != 0)
1058 			*nphdrs = shdr.sh_info;
1059 	}
1060 
1061 	return (0);
1062 }
1063 
1064 #ifdef _ELF32_COMPAT
1065 extern size_t elf_nphdr_max;
1066 #else
1067 size_t elf_nphdr_max = 1000;
1068 #endif
1069 
1070 static int
getelfphdr(vnode_t * vp,cred_t * credp,const Ehdr * ehdr,int nphdrs,caddr_t * phbasep,ssize_t * phsizep)1071 getelfphdr(vnode_t *vp, cred_t *credp, const Ehdr *ehdr, int nphdrs,
1072     caddr_t *phbasep, ssize_t *phsizep)
1073 {
1074 	ssize_t resid, minsize;
1075 	int err;
1076 
1077 	/*
1078 	 * Since we're going to be using e_phentsize to iterate down the
1079 	 * array of program headers, it must be 8-byte aligned or else
1080 	 * a we might cause a misaligned access. We use all members through
1081 	 * p_flags on 32-bit ELF files and p_memsz on 64-bit ELF files so
1082 	 * e_phentsize must be at least large enough to include those
1083 	 * members.
1084 	 */
1085 #if !defined(_LP64) || defined(_ELF32_COMPAT)
1086 	minsize = offsetof(Phdr, p_flags) + sizeof (((Phdr *)NULL)->p_flags);
1087 #else
1088 	minsize = offsetof(Phdr, p_memsz) + sizeof (((Phdr *)NULL)->p_memsz);
1089 #endif
1090 	if (ehdr->e_phentsize < minsize || (ehdr->e_phentsize & 3))
1091 		return (EINVAL);
1092 
1093 	*phsizep = nphdrs * ehdr->e_phentsize;
1094 
1095 	if (*phsizep > sizeof (Phdr) * elf_nphdr_max) {
1096 		if ((*phbasep = kmem_alloc(*phsizep, KM_NOSLEEP)) == NULL)
1097 			return (ENOMEM);
1098 	} else {
1099 		*phbasep = kmem_alloc(*phsizep, KM_SLEEP);
1100 	}
1101 
1102 	if ((err = vn_rdwr(UIO_READ, vp, *phbasep, *phsizep,
1103 	    (offset_t)ehdr->e_phoff, UIO_SYSSPACE, 0, (rlim64_t)0,
1104 	    credp, &resid)) != 0) {
1105 		kmem_free(*phbasep, *phsizep);
1106 		*phbasep = NULL;
1107 		return (err);
1108 	}
1109 
1110 	return (0);
1111 }
1112 
1113 #ifdef _ELF32_COMPAT
1114 extern size_t elf_nshdr_max;
1115 extern size_t elf_shstrtab_max;
1116 #else
1117 size_t elf_nshdr_max = 10000;
1118 size_t elf_shstrtab_max = 100 * 1024;
1119 #endif
1120 
1121 
1122 static int
getelfshdr(vnode_t * vp,cred_t * credp,const Ehdr * ehdr,int nshdrs,int shstrndx,caddr_t * shbasep,ssize_t * shsizep,char ** shstrbasep,ssize_t * shstrsizep)1123 getelfshdr(vnode_t *vp, cred_t *credp, const Ehdr *ehdr,
1124     int nshdrs, int shstrndx, caddr_t *shbasep, ssize_t *shsizep,
1125     char **shstrbasep, ssize_t *shstrsizep)
1126 {
1127 	ssize_t resid, minsize;
1128 	int err;
1129 	Shdr *shdr;
1130 
1131 	/*
1132 	 * Since we're going to be using e_shentsize to iterate down the
1133 	 * array of section headers, it must be 8-byte aligned or else
1134 	 * a we might cause a misaligned access. We use all members through
1135 	 * sh_entsize (on both 32- and 64-bit ELF files) so e_shentsize
1136 	 * must be at least large enough to include that member. The index
1137 	 * of the string table section must also be valid.
1138 	 */
1139 	minsize = offsetof(Shdr, sh_entsize) + sizeof (shdr->sh_entsize);
1140 	if (ehdr->e_shentsize < minsize || (ehdr->e_shentsize & 3) ||
1141 	    shstrndx >= nshdrs)
1142 		return (EINVAL);
1143 
1144 	*shsizep = nshdrs * ehdr->e_shentsize;
1145 
1146 	if (*shsizep > sizeof (Shdr) * elf_nshdr_max) {
1147 		if ((*shbasep = kmem_alloc(*shsizep, KM_NOSLEEP)) == NULL)
1148 			return (ENOMEM);
1149 	} else {
1150 		*shbasep = kmem_alloc(*shsizep, KM_SLEEP);
1151 	}
1152 
1153 	if ((err = vn_rdwr(UIO_READ, vp, *shbasep, *shsizep,
1154 	    (offset_t)ehdr->e_shoff, UIO_SYSSPACE, 0, (rlim64_t)0,
1155 	    credp, &resid)) != 0) {
1156 		kmem_free(*shbasep, *shsizep);
1157 		return (err);
1158 	}
1159 
1160 	/*
1161 	 * Pull the section string table out of the vnode; fail if the size
1162 	 * is zero.
1163 	 */
1164 	shdr = (Shdr *)(*shbasep + shstrndx * ehdr->e_shentsize);
1165 	if ((*shstrsizep = shdr->sh_size) == 0) {
1166 		kmem_free(*shbasep, *shsizep);
1167 		return (EINVAL);
1168 	}
1169 
1170 	if (*shstrsizep > elf_shstrtab_max) {
1171 		if ((*shstrbasep = kmem_alloc(*shstrsizep,
1172 		    KM_NOSLEEP)) == NULL) {
1173 			kmem_free(*shbasep, *shsizep);
1174 			return (ENOMEM);
1175 		}
1176 	} else {
1177 		*shstrbasep = kmem_alloc(*shstrsizep, KM_SLEEP);
1178 	}
1179 
1180 	if ((err = vn_rdwr(UIO_READ, vp, *shstrbasep, *shstrsizep,
1181 	    (offset_t)shdr->sh_offset, UIO_SYSSPACE, 0, (rlim64_t)0,
1182 	    credp, &resid)) != 0) {
1183 		kmem_free(*shbasep, *shsizep);
1184 		kmem_free(*shstrbasep, *shstrsizep);
1185 		return (err);
1186 	}
1187 
1188 	/*
1189 	 * Make sure the strtab is null-terminated to make sure we
1190 	 * don't run off the end of the table.
1191 	 */
1192 	(*shstrbasep)[*shstrsizep - 1] = '\0';
1193 
1194 	return (0);
1195 }
1196 
1197 static int
mapelfexec(vnode_t * vp,Ehdr * ehdr,int nphdrs,caddr_t phdrbase,Phdr ** uphdr,Phdr ** dyphdr,Phdr ** stphdr,Phdr ** dtphdr,Phdr * dataphdrp,caddr_t * bssbase,caddr_t * brkbase,intptr_t * voffset,intptr_t * minaddr,size_t len,long * execsz,size_t * brksize)1198 mapelfexec(
1199 	vnode_t *vp,
1200 	Ehdr *ehdr,
1201 	int nphdrs,
1202 	caddr_t phdrbase,
1203 	Phdr **uphdr,
1204 	Phdr **dyphdr,
1205 	Phdr **stphdr,
1206 	Phdr **dtphdr,
1207 	Phdr *dataphdrp,
1208 	caddr_t *bssbase,
1209 	caddr_t *brkbase,
1210 	intptr_t *voffset,
1211 	intptr_t *minaddr,
1212 	size_t len,
1213 	long *execsz,
1214 	size_t *brksize)
1215 {
1216 	Phdr *phdr;
1217 	int i, prot, error;
1218 	caddr_t addr = NULL;
1219 	size_t zfodsz;
1220 	int ptload = 0;
1221 	int page;
1222 	off_t offset;
1223 	int hsize = ehdr->e_phentsize;
1224 	caddr_t mintmp = (caddr_t)-1;
1225 	extern int use_brk_lpg;
1226 
1227 	if (ehdr->e_type == ET_DYN) {
1228 		/*
1229 		 * Obtain the virtual address of a hole in the
1230 		 * address space to map the "interpreter".
1231 		 */
1232 		map_addr(&addr, len, (offset_t)0, 1, 0);
1233 		if (addr == NULL)
1234 			return (ENOMEM);
1235 		*voffset = (intptr_t)addr;
1236 
1237 		/*
1238 		 * Calculate the minimum vaddr so it can be subtracted out.
1239 		 * According to the ELF specification, since PT_LOAD sections
1240 		 * must be sorted by increasing p_vaddr values, this is
1241 		 * guaranteed to be the first PT_LOAD section.
1242 		 */
1243 		phdr = (Phdr *)phdrbase;
1244 		for (i = nphdrs; i > 0; i--) {
1245 			if (phdr->p_type == PT_LOAD) {
1246 				*voffset -= (uintptr_t)phdr->p_vaddr;
1247 				break;
1248 			}
1249 			phdr = (Phdr *)((caddr_t)phdr + hsize);
1250 		}
1251 
1252 	} else {
1253 		*voffset = 0;
1254 	}
1255 	phdr = (Phdr *)phdrbase;
1256 	for (i = nphdrs; i > 0; i--) {
1257 		switch (phdr->p_type) {
1258 		case PT_LOAD:
1259 			if ((*dyphdr != NULL) && (*uphdr == NULL))
1260 				return (0);
1261 
1262 			ptload = 1;
1263 			prot = PROT_USER;
1264 			if (phdr->p_flags & PF_R)
1265 				prot |= PROT_READ;
1266 			if (phdr->p_flags & PF_W)
1267 				prot |= PROT_WRITE;
1268 			if (phdr->p_flags & PF_X)
1269 				prot |= PROT_EXEC;
1270 
1271 			addr = (caddr_t)((uintptr_t)phdr->p_vaddr + *voffset);
1272 
1273 			/*
1274 			 * Keep track of the segment with the lowest starting
1275 			 * address.
1276 			 */
1277 			if (addr < mintmp)
1278 				mintmp = addr;
1279 
1280 			zfodsz = (size_t)phdr->p_memsz - phdr->p_filesz;
1281 
1282 			offset = phdr->p_offset;
1283 			if (((uintptr_t)offset & PAGEOFFSET) ==
1284 			    ((uintptr_t)addr & PAGEOFFSET) &&
1285 			    (!(vp->v_flag & VNOMAP))) {
1286 				page = 1;
1287 			} else {
1288 				page = 0;
1289 			}
1290 
1291 			/*
1292 			 * Set the heap pagesize for OOB when the bss size
1293 			 * is known and use_brk_lpg is not 0.
1294 			 */
1295 			if (brksize != NULL && use_brk_lpg &&
1296 			    zfodsz != 0 && phdr == dataphdrp &&
1297 			    (prot & PROT_WRITE)) {
1298 				size_t tlen = P2NPHASE((uintptr_t)addr +
1299 				    phdr->p_filesz, PAGESIZE);
1300 
1301 				if (zfodsz > tlen) {
1302 					curproc->p_brkpageszc =
1303 					    page_szc(map_pgsz(MAPPGSZ_HEAP,
1304 					    curproc, addr + phdr->p_filesz +
1305 					    tlen, zfodsz - tlen, 0));
1306 				}
1307 			}
1308 
1309 			if (curproc->p_brkpageszc != 0 && phdr == dataphdrp &&
1310 			    (prot & PROT_WRITE)) {
1311 				uint_t	szc = curproc->p_brkpageszc;
1312 				size_t pgsz = page_get_pagesize(szc);
1313 				caddr_t ebss = addr + phdr->p_memsz;
1314 				size_t extra_zfodsz;
1315 
1316 				ASSERT(pgsz > PAGESIZE);
1317 
1318 				extra_zfodsz = P2NPHASE((uintptr_t)ebss, pgsz);
1319 
1320 				if (error = execmap(vp, addr, phdr->p_filesz,
1321 				    zfodsz + extra_zfodsz, phdr->p_offset,
1322 				    prot, page, szc))
1323 					goto bad;
1324 				if (brksize != NULL)
1325 					*brksize = extra_zfodsz;
1326 			} else {
1327 				if (error = execmap(vp, addr, phdr->p_filesz,
1328 				    zfodsz, phdr->p_offset, prot, page, 0))
1329 					goto bad;
1330 			}
1331 
1332 			if (bssbase != NULL && addr >= *bssbase &&
1333 			    phdr == dataphdrp) {
1334 				*bssbase = addr + phdr->p_filesz;
1335 			}
1336 			if (brkbase != NULL && addr >= *brkbase) {
1337 				*brkbase = addr + phdr->p_memsz;
1338 			}
1339 
1340 			*execsz += btopr(phdr->p_memsz);
1341 			break;
1342 
1343 		case PT_INTERP:
1344 			if (ptload)
1345 				goto bad;
1346 			*dyphdr = phdr;
1347 			break;
1348 
1349 		case PT_SHLIB:
1350 			*stphdr = phdr;
1351 			break;
1352 
1353 		case PT_PHDR:
1354 			if (ptload)
1355 				goto bad;
1356 			*uphdr = phdr;
1357 			break;
1358 
1359 		case PT_NULL:
1360 		case PT_DYNAMIC:
1361 		case PT_NOTE:
1362 			break;
1363 
1364 		case PT_SUNWDTRACE:
1365 			if (dtphdr != NULL)
1366 				*dtphdr = phdr;
1367 			break;
1368 
1369 		default:
1370 			break;
1371 		}
1372 		phdr = (Phdr *)((caddr_t)phdr + hsize);
1373 	}
1374 
1375 	if (minaddr != NULL) {
1376 		ASSERT(mintmp != (caddr_t)-1);
1377 		*minaddr = (intptr_t)mintmp;
1378 	}
1379 
1380 	return (0);
1381 bad:
1382 	if (error == 0)
1383 		error = EINVAL;
1384 	return (error);
1385 }
1386 
1387 int
elfnote(vnode_t * vp,offset_t * offsetp,int type,int descsz,void * desc,rlim64_t rlimit,cred_t * credp)1388 elfnote(vnode_t *vp, offset_t *offsetp, int type, int descsz, void *desc,
1389     rlim64_t rlimit, cred_t *credp)
1390 {
1391 	Note note;
1392 	int error;
1393 
1394 	bzero(&note, sizeof (note));
1395 	bcopy("CORE", note.name, 4);
1396 	note.nhdr.n_type = type;
1397 	/*
1398 	 * The System V ABI states that n_namesz must be the length of the
1399 	 * string that follows the Nhdr structure including the terminating
1400 	 * null. The ABI also specifies that sufficient padding should be
1401 	 * included so that the description that follows the name string
1402 	 * begins on a 4- or 8-byte boundary for 32- and 64-bit binaries
1403 	 * respectively. However, since this change was not made correctly
1404 	 * at the time of the 64-bit port, both 32- and 64-bit binaries
1405 	 * descriptions are only guaranteed to begin on a 4-byte boundary.
1406 	 */
1407 	note.nhdr.n_namesz = 5;
1408 	note.nhdr.n_descsz = roundup(descsz, sizeof (Word));
1409 
1410 	if (error = core_write(vp, UIO_SYSSPACE, *offsetp, &note,
1411 	    sizeof (note), rlimit, credp))
1412 		return (error);
1413 
1414 	*offsetp += sizeof (note);
1415 
1416 	if (error = core_write(vp, UIO_SYSSPACE, *offsetp, desc,
1417 	    note.nhdr.n_descsz, rlimit, credp))
1418 		return (error);
1419 
1420 	*offsetp += note.nhdr.n_descsz;
1421 	return (0);
1422 }
1423 
1424 /*
1425  * Copy the section data from one vnode to the section of another vnode.
1426  */
1427 static void
copy_scn(Shdr * src,vnode_t * src_vp,Shdr * dst,vnode_t * dst_vp,Off * doffset,void * buf,size_t size,cred_t * credp,rlim64_t rlimit)1428 copy_scn(Shdr *src, vnode_t *src_vp, Shdr *dst, vnode_t *dst_vp, Off *doffset,
1429     void *buf, size_t size, cred_t *credp, rlim64_t rlimit)
1430 {
1431 	ssize_t resid;
1432 	size_t len, n = src->sh_size;
1433 	offset_t off = 0;
1434 
1435 	while (n != 0) {
1436 		len = MIN(size, n);
1437 		if (vn_rdwr(UIO_READ, src_vp, buf, len, src->sh_offset + off,
1438 		    UIO_SYSSPACE, 0, (rlim64_t)0, credp, &resid) != 0 ||
1439 		    resid >= len ||
1440 		    core_write(dst_vp, UIO_SYSSPACE, *doffset + off,
1441 		    buf, len - resid, rlimit, credp) != 0) {
1442 			dst->sh_size = 0;
1443 			dst->sh_offset = 0;
1444 			return;
1445 		}
1446 
1447 		ASSERT(n >= len - resid);
1448 
1449 		n -= len - resid;
1450 		off += len - resid;
1451 	}
1452 
1453 	*doffset += src->sh_size;
1454 }
1455 
1456 #ifdef _ELF32_COMPAT
1457 extern size_t elf_datasz_max;
1458 #else
1459 size_t elf_datasz_max = 1 * 1024 * 1024;
1460 #endif
1461 
1462 /*
1463  * This function processes mappings that correspond to load objects to
1464  * examine their respective sections for elfcore(). It's called once with
1465  * v set to NULL to count the number of sections that we're going to need
1466  * and then again with v set to some allocated buffer that we fill in with
1467  * all the section data.
1468  */
1469 static int
process_scns(core_content_t content,proc_t * p,cred_t * credp,vnode_t * vp,Shdr * v,int nv,rlim64_t rlimit,Off * doffsetp,int * nshdrsp)1470 process_scns(core_content_t content, proc_t *p, cred_t *credp, vnode_t *vp,
1471     Shdr *v, int nv, rlim64_t rlimit, Off *doffsetp, int *nshdrsp)
1472 {
1473 	vnode_t *lastvp = NULL;
1474 	struct seg *seg;
1475 	int i, j;
1476 	void *data = NULL;
1477 	size_t datasz = 0;
1478 	shstrtab_t shstrtab;
1479 	struct as *as = p->p_as;
1480 	int error = 0;
1481 
1482 	if (v != NULL)
1483 		shstrtab_init(&shstrtab);
1484 
1485 	i = 1;
1486 	for (seg = AS_SEGFIRST(as); seg != NULL; seg = AS_SEGNEXT(as, seg)) {
1487 		uint_t prot;
1488 		vnode_t *mvp;
1489 		void *tmp = NULL;
1490 		caddr_t saddr = seg->s_base;
1491 		caddr_t naddr;
1492 		caddr_t eaddr;
1493 		size_t segsize;
1494 
1495 		Ehdr ehdr;
1496 		int nshdrs, shstrndx, nphdrs;
1497 		caddr_t shbase;
1498 		ssize_t shsize;
1499 		char *shstrbase;
1500 		ssize_t shstrsize;
1501 
1502 		Shdr *shdr;
1503 		const char *name;
1504 		size_t sz;
1505 		uintptr_t off;
1506 
1507 		int ctf_ndx = 0;
1508 		int symtab_ndx = 0;
1509 
1510 		/*
1511 		 * Since we're just looking for text segments of load
1512 		 * objects, we only care about the protection bits; we don't
1513 		 * care about the actual size of the segment so we use the
1514 		 * reserved size. If the segment's size is zero, there's
1515 		 * something fishy going on so we ignore this segment.
1516 		 */
1517 		if (seg->s_ops != &segvn_ops ||
1518 		    SEGOP_GETVP(seg, seg->s_base, &mvp) != 0 ||
1519 		    mvp == lastvp || mvp == NULL || mvp->v_type != VREG ||
1520 		    (segsize = pr_getsegsize(seg, 1)) == 0)
1521 			continue;
1522 
1523 		eaddr = saddr + segsize;
1524 		prot = pr_getprot(seg, 1, &tmp, &saddr, &naddr, eaddr);
1525 		pr_getprot_done(&tmp);
1526 
1527 		/*
1528 		 * Skip this segment unless the protection bits look like
1529 		 * what we'd expect for a text segment.
1530 		 */
1531 		if ((prot & (PROT_WRITE | PROT_EXEC)) != PROT_EXEC)
1532 			continue;
1533 
1534 		if (getelfhead(mvp, credp, &ehdr, &nshdrs, &shstrndx,
1535 		    &nphdrs) != 0 ||
1536 		    getelfshdr(mvp, credp, &ehdr, nshdrs, shstrndx,
1537 		    &shbase, &shsize, &shstrbase, &shstrsize) != 0)
1538 			continue;
1539 
1540 		off = ehdr.e_shentsize;
1541 		for (j = 1; j < nshdrs; j++, off += ehdr.e_shentsize) {
1542 			Shdr *symtab = NULL, *strtab;
1543 
1544 			shdr = (Shdr *)(shbase + off);
1545 
1546 			if (shdr->sh_name >= shstrsize)
1547 				continue;
1548 
1549 			name = shstrbase + shdr->sh_name;
1550 
1551 			if (strcmp(name, shstrtab_data[STR_CTF]) == 0) {
1552 				if ((content & CC_CONTENT_CTF) == 0 ||
1553 				    ctf_ndx != 0)
1554 					continue;
1555 
1556 				if (shdr->sh_link > 0 &&
1557 				    shdr->sh_link < nshdrs) {
1558 					symtab = (Shdr *)(shbase +
1559 					    shdr->sh_link * ehdr.e_shentsize);
1560 				}
1561 
1562 				if (v != NULL && i < nv - 1) {
1563 					if (shdr->sh_size > datasz &&
1564 					    shdr->sh_size <= elf_datasz_max) {
1565 						if (data != NULL)
1566 							kmem_free(data, datasz);
1567 
1568 						datasz = shdr->sh_size;
1569 						data = kmem_alloc(datasz,
1570 						    KM_SLEEP);
1571 					}
1572 
1573 					v[i].sh_name = shstrtab_ndx(&shstrtab,
1574 					    STR_CTF);
1575 					v[i].sh_addr = (Addr)(uintptr_t)saddr;
1576 					v[i].sh_type = SHT_PROGBITS;
1577 					v[i].sh_addralign = 4;
1578 					*doffsetp = roundup(*doffsetp,
1579 					    v[i].sh_addralign);
1580 					v[i].sh_offset = *doffsetp;
1581 					v[i].sh_size = shdr->sh_size;
1582 					if (symtab == NULL)  {
1583 						v[i].sh_link = 0;
1584 					} else if (symtab->sh_type ==
1585 					    SHT_SYMTAB &&
1586 					    symtab_ndx != 0) {
1587 						v[i].sh_link =
1588 						    symtab_ndx;
1589 					} else {
1590 						v[i].sh_link = i + 1;
1591 					}
1592 
1593 					copy_scn(shdr, mvp, &v[i], vp,
1594 					    doffsetp, data, datasz, credp,
1595 					    rlimit);
1596 				}
1597 
1598 				ctf_ndx = i++;
1599 
1600 				/*
1601 				 * We've already dumped the symtab.
1602 				 */
1603 				if (symtab != NULL &&
1604 				    symtab->sh_type == SHT_SYMTAB &&
1605 				    symtab_ndx != 0)
1606 					continue;
1607 
1608 			} else if (strcmp(name,
1609 			    shstrtab_data[STR_SYMTAB]) == 0) {
1610 				if ((content & CC_CONTENT_SYMTAB) == 0 ||
1611 				    symtab != 0)
1612 					continue;
1613 
1614 				symtab = shdr;
1615 			}
1616 
1617 			if (symtab != NULL) {
1618 				if ((symtab->sh_type != SHT_DYNSYM &&
1619 				    symtab->sh_type != SHT_SYMTAB) ||
1620 				    symtab->sh_link == 0 ||
1621 				    symtab->sh_link >= nshdrs)
1622 					continue;
1623 
1624 				strtab = (Shdr *)(shbase +
1625 				    symtab->sh_link * ehdr.e_shentsize);
1626 
1627 				if (strtab->sh_type != SHT_STRTAB)
1628 					continue;
1629 
1630 				if (v != NULL && i < nv - 2) {
1631 					sz = MAX(symtab->sh_size,
1632 					    strtab->sh_size);
1633 					if (sz > datasz &&
1634 					    sz <= elf_datasz_max) {
1635 						if (data != NULL)
1636 							kmem_free(data, datasz);
1637 
1638 						datasz = sz;
1639 						data = kmem_alloc(datasz,
1640 						    KM_SLEEP);
1641 					}
1642 
1643 					if (symtab->sh_type == SHT_DYNSYM) {
1644 						v[i].sh_name = shstrtab_ndx(
1645 						    &shstrtab, STR_DYNSYM);
1646 						v[i + 1].sh_name = shstrtab_ndx(
1647 						    &shstrtab, STR_DYNSTR);
1648 					} else {
1649 						v[i].sh_name = shstrtab_ndx(
1650 						    &shstrtab, STR_SYMTAB);
1651 						v[i + 1].sh_name = shstrtab_ndx(
1652 						    &shstrtab, STR_STRTAB);
1653 					}
1654 
1655 					v[i].sh_type = symtab->sh_type;
1656 					v[i].sh_addr = symtab->sh_addr;
1657 					if (ehdr.e_type == ET_DYN ||
1658 					    v[i].sh_addr == 0)
1659 						v[i].sh_addr +=
1660 						    (Addr)(uintptr_t)saddr;
1661 					v[i].sh_addralign =
1662 					    symtab->sh_addralign;
1663 					*doffsetp = roundup(*doffsetp,
1664 					    v[i].sh_addralign);
1665 					v[i].sh_offset = *doffsetp;
1666 					v[i].sh_size = symtab->sh_size;
1667 					v[i].sh_link = i + 1;
1668 					v[i].sh_entsize = symtab->sh_entsize;
1669 					v[i].sh_info = symtab->sh_info;
1670 
1671 					copy_scn(symtab, mvp, &v[i], vp,
1672 					    doffsetp, data, datasz, credp,
1673 					    rlimit);
1674 
1675 					v[i + 1].sh_type = SHT_STRTAB;
1676 					v[i + 1].sh_flags = SHF_STRINGS;
1677 					v[i + 1].sh_addr = symtab->sh_addr;
1678 					if (ehdr.e_type == ET_DYN ||
1679 					    v[i + 1].sh_addr == 0)
1680 						v[i + 1].sh_addr +=
1681 						    (Addr)(uintptr_t)saddr;
1682 					v[i + 1].sh_addralign =
1683 					    strtab->sh_addralign;
1684 					*doffsetp = roundup(*doffsetp,
1685 					    v[i + 1].sh_addralign);
1686 					v[i + 1].sh_offset = *doffsetp;
1687 					v[i + 1].sh_size = strtab->sh_size;
1688 
1689 					copy_scn(strtab, mvp, &v[i + 1], vp,
1690 					    doffsetp, data, datasz, credp,
1691 					    rlimit);
1692 				}
1693 
1694 				if (symtab->sh_type == SHT_SYMTAB)
1695 					symtab_ndx = i;
1696 				i += 2;
1697 			}
1698 		}
1699 
1700 		kmem_free(shstrbase, shstrsize);
1701 		kmem_free(shbase, shsize);
1702 
1703 		lastvp = mvp;
1704 	}
1705 
1706 	if (v == NULL) {
1707 		if (i == 1)
1708 			*nshdrsp = 0;
1709 		else
1710 			*nshdrsp = i + 1;
1711 		goto done;
1712 	}
1713 
1714 	if (i != nv - 1) {
1715 		cmn_err(CE_WARN, "elfcore: core dump failed for "
1716 		    "process %d; address space is changing", p->p_pid);
1717 		error = EIO;
1718 		goto done;
1719 	}
1720 
1721 	v[i].sh_name = shstrtab_ndx(&shstrtab, STR_SHSTRTAB);
1722 	v[i].sh_size = shstrtab_size(&shstrtab);
1723 	v[i].sh_addralign = 1;
1724 	*doffsetp = roundup(*doffsetp, v[i].sh_addralign);
1725 	v[i].sh_offset = *doffsetp;
1726 	v[i].sh_flags = SHF_STRINGS;
1727 	v[i].sh_type = SHT_STRTAB;
1728 
1729 	if (v[i].sh_size > datasz) {
1730 		if (data != NULL)
1731 			kmem_free(data, datasz);
1732 
1733 		datasz = v[i].sh_size;
1734 		data = kmem_alloc(datasz,
1735 		    KM_SLEEP);
1736 	}
1737 
1738 	shstrtab_dump(&shstrtab, data);
1739 
1740 	if ((error = core_write(vp, UIO_SYSSPACE, *doffsetp,
1741 	    data, v[i].sh_size, rlimit, credp)) != 0)
1742 		goto done;
1743 
1744 	*doffsetp += v[i].sh_size;
1745 
1746 done:
1747 	if (data != NULL)
1748 		kmem_free(data, datasz);
1749 
1750 	return (error);
1751 }
1752 
1753 int
elfcore(vnode_t * vp,proc_t * p,cred_t * credp,rlim64_t rlimit,int sig,core_content_t content)1754 elfcore(vnode_t *vp, proc_t *p, cred_t *credp, rlim64_t rlimit, int sig,
1755     core_content_t content)
1756 {
1757 	offset_t poffset, soffset;
1758 	Off doffset;
1759 	int error, i, nphdrs, nshdrs;
1760 	int overflow = 0;
1761 	struct seg *seg;
1762 	struct as *as = p->p_as;
1763 	union {
1764 		Ehdr ehdr;
1765 		Phdr phdr[1];
1766 		Shdr shdr[1];
1767 	} *bigwad;
1768 	size_t bigsize;
1769 	size_t phdrsz, shdrsz;
1770 	Ehdr *ehdr;
1771 	Phdr *v;
1772 	caddr_t brkbase;
1773 	size_t brksize;
1774 	caddr_t stkbase;
1775 	size_t stksize;
1776 	int ntries = 0;
1777 	klwp_t *lwp = ttolwp(curthread);
1778 
1779 top:
1780 	/*
1781 	 * Make sure we have everything we need (registers, etc.).
1782 	 * All other lwps have already stopped and are in an orderly state.
1783 	 */
1784 	ASSERT(p == ttoproc(curthread));
1785 	prstop(0, 0);
1786 
1787 	AS_LOCK_ENTER(as, RW_WRITER);
1788 	nphdrs = prnsegs(as, 0) + 2;		/* two CORE note sections */
1789 
1790 	/*
1791 	 * Count the number of section headers we're going to need.
1792 	 */
1793 	nshdrs = 0;
1794 	if (content & (CC_CONTENT_CTF | CC_CONTENT_SYMTAB)) {
1795 		(void) process_scns(content, p, credp, NULL, NULL, NULL, 0,
1796 		    NULL, &nshdrs);
1797 	}
1798 	AS_LOCK_EXIT(as);
1799 
1800 	ASSERT(nshdrs == 0 || nshdrs > 1);
1801 
1802 	/*
1803 	 * The core file contents may required zero section headers, but if
1804 	 * we overflow the 16 bits allotted to the program header count in
1805 	 * the ELF header, we'll need that program header at index zero.
1806 	 */
1807 	if (nshdrs == 0 && nphdrs >= PN_XNUM)
1808 		nshdrs = 1;
1809 
1810 	phdrsz = nphdrs * sizeof (Phdr);
1811 	shdrsz = nshdrs * sizeof (Shdr);
1812 
1813 	bigsize = MAX(sizeof (*bigwad), MAX(phdrsz, shdrsz));
1814 	bigwad = kmem_alloc(bigsize, KM_SLEEP);
1815 
1816 	ehdr = &bigwad->ehdr;
1817 	bzero(ehdr, sizeof (*ehdr));
1818 
1819 	ehdr->e_ident[EI_MAG0] = ELFMAG0;
1820 	ehdr->e_ident[EI_MAG1] = ELFMAG1;
1821 	ehdr->e_ident[EI_MAG2] = ELFMAG2;
1822 	ehdr->e_ident[EI_MAG3] = ELFMAG3;
1823 	ehdr->e_ident[EI_CLASS] = ELFCLASS;
1824 	ehdr->e_type = ET_CORE;
1825 
1826 #if !defined(_LP64) || defined(_ELF32_COMPAT)
1827 
1828 #if defined(__sparc)
1829 	ehdr->e_ident[EI_DATA] = ELFDATA2MSB;
1830 	ehdr->e_machine = EM_SPARC;
1831 #elif defined(__i386) || defined(__i386_COMPAT)
1832 	ehdr->e_ident[EI_DATA] = ELFDATA2LSB;
1833 	ehdr->e_machine = EM_386;
1834 #else
1835 #error "no recognized machine type is defined"
1836 #endif
1837 
1838 #else	/* !defined(_LP64) || defined(_ELF32_COMPAT) */
1839 
1840 #if defined(__sparc)
1841 	ehdr->e_ident[EI_DATA] = ELFDATA2MSB;
1842 	ehdr->e_machine = EM_SPARCV9;
1843 #elif defined(__amd64)
1844 	ehdr->e_ident[EI_DATA] = ELFDATA2LSB;
1845 	ehdr->e_machine = EM_AMD64;
1846 #else
1847 #error "no recognized 64-bit machine type is defined"
1848 #endif
1849 
1850 #endif	/* !defined(_LP64) || defined(_ELF32_COMPAT) */
1851 
1852 	/*
1853 	 * If the count of program headers or section headers or the index
1854 	 * of the section string table can't fit in the mere 16 bits
1855 	 * shortsightedly allotted to them in the ELF header, we use the
1856 	 * extended formats and put the real values in the section header
1857 	 * as index 0.
1858 	 */
1859 	ehdr->e_version = EV_CURRENT;
1860 	ehdr->e_ehsize = sizeof (Ehdr);
1861 
1862 	if (nphdrs >= PN_XNUM)
1863 		ehdr->e_phnum = PN_XNUM;
1864 	else
1865 		ehdr->e_phnum = (unsigned short)nphdrs;
1866 
1867 	ehdr->e_phoff = sizeof (Ehdr);
1868 	ehdr->e_phentsize = sizeof (Phdr);
1869 
1870 	if (nshdrs > 0) {
1871 		if (nshdrs >= SHN_LORESERVE)
1872 			ehdr->e_shnum = 0;
1873 		else
1874 			ehdr->e_shnum = (unsigned short)nshdrs;
1875 
1876 		if (nshdrs - 1 >= SHN_LORESERVE)
1877 			ehdr->e_shstrndx = SHN_XINDEX;
1878 		else
1879 			ehdr->e_shstrndx = (unsigned short)(nshdrs - 1);
1880 
1881 		ehdr->e_shoff = ehdr->e_phoff + ehdr->e_phentsize * nphdrs;
1882 		ehdr->e_shentsize = sizeof (Shdr);
1883 	}
1884 
1885 	if (error = core_write(vp, UIO_SYSSPACE, (offset_t)0, ehdr,
1886 	    sizeof (Ehdr), rlimit, credp))
1887 		goto done;
1888 
1889 	poffset = sizeof (Ehdr);
1890 	soffset = sizeof (Ehdr) + phdrsz;
1891 	doffset = sizeof (Ehdr) + phdrsz + shdrsz;
1892 
1893 	v = &bigwad->phdr[0];
1894 	bzero(v, phdrsz);
1895 
1896 	setup_old_note_header(&v[0], p);
1897 	v[0].p_offset = doffset = roundup(doffset, sizeof (Word));
1898 	doffset += v[0].p_filesz;
1899 
1900 	setup_note_header(&v[1], p);
1901 	v[1].p_offset = doffset = roundup(doffset, sizeof (Word));
1902 	doffset += v[1].p_filesz;
1903 
1904 	mutex_enter(&p->p_lock);
1905 
1906 	brkbase = p->p_brkbase;
1907 	brksize = p->p_brksize;
1908 
1909 	stkbase = p->p_usrstack - p->p_stksize;
1910 	stksize = p->p_stksize;
1911 
1912 	mutex_exit(&p->p_lock);
1913 
1914 	AS_LOCK_ENTER(as, RW_WRITER);
1915 	i = 2;
1916 	for (seg = AS_SEGFIRST(as); seg != NULL; seg = AS_SEGNEXT(as, seg)) {
1917 		caddr_t eaddr = seg->s_base + pr_getsegsize(seg, 0);
1918 		caddr_t saddr, naddr;
1919 		void *tmp = NULL;
1920 		extern struct seg_ops segspt_shmops;
1921 
1922 		for (saddr = seg->s_base; saddr < eaddr; saddr = naddr) {
1923 			uint_t prot;
1924 			size_t size;
1925 			int type;
1926 			vnode_t *mvp;
1927 
1928 			prot = pr_getprot(seg, 0, &tmp, &saddr, &naddr, eaddr);
1929 			prot &= PROT_READ | PROT_WRITE | PROT_EXEC;
1930 			if ((size = (size_t)(naddr - saddr)) == 0)
1931 				continue;
1932 			if (i == nphdrs) {
1933 				overflow++;
1934 				continue;
1935 			}
1936 			v[i].p_type = PT_LOAD;
1937 			v[i].p_vaddr = (Addr)(uintptr_t)saddr;
1938 			v[i].p_memsz = size;
1939 			if (prot & PROT_READ)
1940 				v[i].p_flags |= PF_R;
1941 			if (prot & PROT_WRITE)
1942 				v[i].p_flags |= PF_W;
1943 			if (prot & PROT_EXEC)
1944 				v[i].p_flags |= PF_X;
1945 
1946 			/*
1947 			 * Figure out which mappings to include in the core.
1948 			 */
1949 			type = SEGOP_GETTYPE(seg, saddr);
1950 
1951 			if (saddr == stkbase && size == stksize) {
1952 				if (!(content & CC_CONTENT_STACK))
1953 					goto exclude;
1954 
1955 			} else if (saddr == brkbase && size == brksize) {
1956 				if (!(content & CC_CONTENT_HEAP))
1957 					goto exclude;
1958 
1959 			} else if (seg->s_ops == &segspt_shmops) {
1960 				if (type & MAP_NORESERVE) {
1961 					if (!(content & CC_CONTENT_DISM))
1962 						goto exclude;
1963 				} else {
1964 					if (!(content & CC_CONTENT_ISM))
1965 						goto exclude;
1966 				}
1967 
1968 			} else if (seg->s_ops != &segvn_ops) {
1969 				goto exclude;
1970 
1971 			} else if (type & MAP_SHARED) {
1972 				if (shmgetid(p, saddr) != SHMID_NONE) {
1973 					if (!(content & CC_CONTENT_SHM))
1974 						goto exclude;
1975 
1976 				} else if (SEGOP_GETVP(seg, seg->s_base,
1977 				    &mvp) != 0 || mvp == NULL ||
1978 				    mvp->v_type != VREG) {
1979 					if (!(content & CC_CONTENT_SHANON))
1980 						goto exclude;
1981 
1982 				} else {
1983 					if (!(content & CC_CONTENT_SHFILE))
1984 						goto exclude;
1985 				}
1986 
1987 			} else if (SEGOP_GETVP(seg, seg->s_base, &mvp) != 0 ||
1988 			    mvp == NULL || mvp->v_type != VREG) {
1989 				if (!(content & CC_CONTENT_ANON))
1990 					goto exclude;
1991 
1992 			} else if (prot == (PROT_READ | PROT_EXEC)) {
1993 				if (!(content & CC_CONTENT_TEXT))
1994 					goto exclude;
1995 
1996 			} else if (prot == PROT_READ) {
1997 				if (!(content & CC_CONTENT_RODATA))
1998 					goto exclude;
1999 
2000 			} else {
2001 				if (!(content & CC_CONTENT_DATA))
2002 					goto exclude;
2003 			}
2004 
2005 			doffset = roundup(doffset, sizeof (Word));
2006 			v[i].p_offset = doffset;
2007 			v[i].p_filesz = size;
2008 			doffset += size;
2009 exclude:
2010 			i++;
2011 		}
2012 		ASSERT(tmp == NULL);
2013 	}
2014 	AS_LOCK_EXIT(as);
2015 
2016 	if (overflow || i != nphdrs) {
2017 		if (ntries++ == 0) {
2018 			kmem_free(bigwad, bigsize);
2019 			overflow = 0;
2020 			goto top;
2021 		}
2022 		cmn_err(CE_WARN, "elfcore: core dump failed for "
2023 		    "process %d; address space is changing", p->p_pid);
2024 		error = EIO;
2025 		goto done;
2026 	}
2027 
2028 	if ((error = core_write(vp, UIO_SYSSPACE, poffset,
2029 	    v, phdrsz, rlimit, credp)) != 0)
2030 		goto done;
2031 
2032 	if ((error = write_old_elfnotes(p, sig, vp, v[0].p_offset, rlimit,
2033 	    credp)) != 0)
2034 		goto done;
2035 
2036 	if ((error = write_elfnotes(p, sig, vp, v[1].p_offset, rlimit,
2037 	    credp, content)) != 0)
2038 		goto done;
2039 
2040 	for (i = 2; i < nphdrs; i++) {
2041 		prkillinfo_t killinfo;
2042 		sigqueue_t *sq;
2043 		int sig, j;
2044 
2045 		if (v[i].p_filesz == 0)
2046 			continue;
2047 
2048 		/*
2049 		 * If dumping out this segment fails, rather than failing
2050 		 * the core dump entirely, we reset the size of the mapping
2051 		 * to zero to indicate that the data is absent from the core
2052 		 * file and or in the PF_SUNW_FAILURE flag to differentiate
2053 		 * this from mappings that were excluded due to the core file
2054 		 * content settings.
2055 		 */
2056 		if ((error = core_seg(p, vp, v[i].p_offset,
2057 		    (caddr_t)(uintptr_t)v[i].p_vaddr, v[i].p_filesz,
2058 		    rlimit, credp)) == 0) {
2059 			continue;
2060 		}
2061 
2062 		if ((sig = lwp->lwp_cursig) == 0) {
2063 			/*
2064 			 * We failed due to something other than a signal.
2065 			 * Since the space reserved for the segment is now
2066 			 * unused, we stash the errno in the first four
2067 			 * bytes. This undocumented interface will let us
2068 			 * understand the nature of the failure.
2069 			 */
2070 			(void) core_write(vp, UIO_SYSSPACE, v[i].p_offset,
2071 			    &error, sizeof (error), rlimit, credp);
2072 
2073 			v[i].p_filesz = 0;
2074 			v[i].p_flags |= PF_SUNW_FAILURE;
2075 			if ((error = core_write(vp, UIO_SYSSPACE,
2076 			    poffset + sizeof (v[i]) * i, &v[i], sizeof (v[i]),
2077 			    rlimit, credp)) != 0)
2078 				goto done;
2079 
2080 			continue;
2081 		}
2082 
2083 		/*
2084 		 * We took a signal.  We want to abort the dump entirely, but
2085 		 * we also want to indicate what failed and why.  We therefore
2086 		 * use the space reserved for the first failing segment to
2087 		 * write our error (which, for purposes of compatability with
2088 		 * older core dump readers, we set to EINTR) followed by any
2089 		 * siginfo associated with the signal.
2090 		 */
2091 		bzero(&killinfo, sizeof (killinfo));
2092 		killinfo.prk_error = EINTR;
2093 
2094 		sq = sig == SIGKILL ? curproc->p_killsqp : lwp->lwp_curinfo;
2095 
2096 		if (sq != NULL) {
2097 			bcopy(&sq->sq_info, &killinfo.prk_info,
2098 			    sizeof (sq->sq_info));
2099 		} else {
2100 			killinfo.prk_info.si_signo = lwp->lwp_cursig;
2101 			killinfo.prk_info.si_code = SI_NOINFO;
2102 		}
2103 
2104 #if (defined(_SYSCALL32_IMPL) || defined(_LP64))
2105 		/*
2106 		 * If this is a 32-bit process, we need to translate from the
2107 		 * native siginfo to the 32-bit variant.  (Core readers must
2108 		 * always have the same data model as their target or must
2109 		 * be aware of -- and compensate for -- data model differences.)
2110 		 */
2111 		if (curproc->p_model == DATAMODEL_ILP32) {
2112 			siginfo32_t si32;
2113 
2114 			siginfo_kto32((k_siginfo_t *)&killinfo.prk_info, &si32);
2115 			bcopy(&si32, &killinfo.prk_info, sizeof (si32));
2116 		}
2117 #endif
2118 
2119 		(void) core_write(vp, UIO_SYSSPACE, v[i].p_offset,
2120 		    &killinfo, sizeof (killinfo), rlimit, credp);
2121 
2122 		/*
2123 		 * For the segment on which we took the signal, indicate that
2124 		 * its data now refers to a siginfo.
2125 		 */
2126 		v[i].p_filesz = 0;
2127 		v[i].p_flags |= PF_SUNW_FAILURE | PF_SUNW_KILLED |
2128 		    PF_SUNW_SIGINFO;
2129 
2130 		/*
2131 		 * And for every other segment, indicate that its absence
2132 		 * is due to a signal.
2133 		 */
2134 		for (j = i + 1; j < nphdrs; j++) {
2135 			v[j].p_filesz = 0;
2136 			v[j].p_flags |= PF_SUNW_FAILURE | PF_SUNW_KILLED;
2137 		}
2138 
2139 		/*
2140 		 * Finally, write out our modified program headers.
2141 		 */
2142 		if ((error = core_write(vp, UIO_SYSSPACE,
2143 		    poffset + sizeof (v[i]) * i, &v[i],
2144 		    sizeof (v[i]) * (nphdrs - i), rlimit, credp)) != 0)
2145 			goto done;
2146 
2147 		break;
2148 	}
2149 
2150 	if (nshdrs > 0) {
2151 		bzero(&bigwad->shdr[0], shdrsz);
2152 
2153 		if (nshdrs >= SHN_LORESERVE)
2154 			bigwad->shdr[0].sh_size = nshdrs;
2155 
2156 		if (nshdrs - 1 >= SHN_LORESERVE)
2157 			bigwad->shdr[0].sh_link = nshdrs - 1;
2158 
2159 		if (nphdrs >= PN_XNUM)
2160 			bigwad->shdr[0].sh_info = nphdrs;
2161 
2162 		if (nshdrs > 1) {
2163 			AS_LOCK_ENTER(as, RW_WRITER);
2164 			if ((error = process_scns(content, p, credp, vp,
2165 			    &bigwad->shdr[0], nshdrs, rlimit, &doffset,
2166 			    NULL)) != 0) {
2167 				AS_LOCK_EXIT(as);
2168 				goto done;
2169 			}
2170 			AS_LOCK_EXIT(as);
2171 		}
2172 
2173 		if ((error = core_write(vp, UIO_SYSSPACE, soffset,
2174 		    &bigwad->shdr[0], shdrsz, rlimit, credp)) != 0)
2175 			goto done;
2176 	}
2177 
2178 done:
2179 	kmem_free(bigwad, bigsize);
2180 	return (error);
2181 }
2182 
2183 #ifndef	_ELF32_COMPAT
2184 
2185 static struct execsw esw = {
2186 #ifdef	_LP64
2187 	elf64magicstr,
2188 #else	/* _LP64 */
2189 	elf32magicstr,
2190 #endif	/* _LP64 */
2191 	0,
2192 	5,
2193 	elfexec,
2194 	elfcore
2195 };
2196 
2197 static struct modlexec modlexec = {
2198 	&mod_execops, "exec module for elf", &esw
2199 };
2200 
2201 #ifdef	_LP64
2202 extern int elf32exec(vnode_t *vp, execa_t *uap, uarg_t *args,
2203 			intpdata_t *idatap, int level, long *execsz,
2204 			int setid, caddr_t exec_file, cred_t *cred,
2205 			int brand_action);
2206 extern int elf32core(vnode_t *vp, proc_t *p, cred_t *credp,
2207 			rlim64_t rlimit, int sig, core_content_t content);
2208 
2209 static struct execsw esw32 = {
2210 	elf32magicstr,
2211 	0,
2212 	5,
2213 	elf32exec,
2214 	elf32core
2215 };
2216 
2217 static struct modlexec modlexec32 = {
2218 	&mod_execops, "32-bit exec module for elf", &esw32
2219 };
2220 #endif	/* _LP64 */
2221 
2222 static struct modlinkage modlinkage = {
2223 	MODREV_1,
2224 	(void *)&modlexec,
2225 #ifdef	_LP64
2226 	(void *)&modlexec32,
2227 #endif	/* _LP64 */
2228 	NULL
2229 };
2230 
2231 int
_init(void)2232 _init(void)
2233 {
2234 	return (mod_install(&modlinkage));
2235 }
2236 
2237 int
_fini(void)2238 _fini(void)
2239 {
2240 	return (mod_remove(&modlinkage));
2241 }
2242 
2243 int
_info(struct modinfo * modinfop)2244 _info(struct modinfo *modinfop)
2245 {
2246 	return (mod_info(&modlinkage, modinfop));
2247 }
2248 
2249 #endif	/* !_ELF32_COMPAT */
2250