xref: /titanic_41/usr/src/cmd/sgs/rtld/common/cap.c (revision 257873cfc1dd3337766407f80397db60a56f2f5a)
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 2008 Sun Microsystems, Inc.  All rights reserved.
24  * Use is subject to license terms.
25  */
26 
27 #include	<sys/types.h>
28 #include	<sys/mman.h>
29 #include	<dirent.h>
30 #include	<stdio.h>
31 #include	<stdlib.h>
32 #include	<string.h>
33 #include	<limits.h>
34 #include	<debug.h>
35 #include	<conv.h>
36 #include	"_rtld.h"
37 #include	"_audit.h"
38 #include	"msg.h"
39 
40 /*
41  * qsort(3c) comparison function.
42  */
43 static int
44 compare(const void *fdesc1, const void *fdesc2)
45 {
46 	ulong_t	hwcap1 = ((Fdesc *)fdesc1)->fd_fmap.fm_hwptr;
47 	ulong_t	hwcap2 = ((Fdesc *)fdesc2)->fd_fmap.fm_hwptr;
48 
49 	if (hwcap1 && (hwcap2 == 0))
50 		return (-1);
51 	if ((hwcap1 == 0) && hwcap2)
52 		return (1);
53 	if ((hwcap1 == 0) && (hwcap2 == 0))
54 		return (0);
55 
56 	if (hwcap1 > hwcap2)
57 		return (-1);
58 	if (hwcap1 < hwcap2)
59 		return (1);
60 	return (0);
61 }
62 
63 /*
64  * Process any hardware and software capabilities.
65  */
66 int
67 cap_check(Rej_desc *rej, Ehdr *ehdr)
68 {
69 	Cap	*cptr;
70 	Phdr	*phdr;
71 	int	cnt;
72 
73 	/* LINTED */
74 	phdr = (Phdr *)((char *)ehdr + ehdr->e_phoff);
75 	for (cnt = 0; cnt < ehdr->e_phnum; cnt++, phdr++) {
76 		Lword	val;
77 
78 		if (phdr->p_type != PT_SUNWCAP)
79 			continue;
80 
81 		/* LINTED */
82 		for (cptr = (Cap *)((char *)ehdr + phdr->p_offset);
83 		    (cptr->c_tag != CA_SUNW_NULL); cptr++) {
84 
85 			if ((cptr->c_tag == CA_SUNW_HW_1) &&
86 			    (rtld_flags2 & RT_FL2_HWCAP)) {
87 				/*
88 				 * If this object defines a set of hardware
89 				 * capability requirements, ensure the kernel
90 				 * can cope with them.
91 				 */
92 				if ((val = (cptr->c_un.c_val & ~hwcap)) != 0) {
93 					static Conv_cap_val_hw1_buf_t cap_buf;
94 
95 					rej->rej_type = SGS_REJ_HWCAP_1;
96 					rej->rej_str =
97 					    conv_cap_val_hw1(val, M_MACH, 0,
98 					    &cap_buf);
99 					return (0);
100 				}
101 
102 				/*
103 				 * Retain this hardware capabilities value for
104 				 * possible later inspection should this object
105 				 * be processed as a filtee.
106 				 */
107 				fmap->fm_hwptr = cptr->c_un.c_val;
108 
109 			}
110 #if	defined(_ELF64)
111 			if (cptr->c_tag == CA_SUNW_SF_1) {
112 				/*
113 				 * A 64-bit executable that started the process
114 				 * can be restricted to a 32-bit address space.
115 				 * A 64-bit dependency that is restricted to a
116 				 * 32-bit address space can not be loaded unless
117 				 * the executable has established this
118 				 * requirement.
119 				 */
120 				if ((cptr->c_un.c_val & SF1_SUNW_ADDR32) &&
121 				    ((rtld_flags2 & RT_FL2_ADDR32) == 0)) {
122 					static Conv_cap_val_sf1_buf_t cap_buf;
123 
124 					rej->rej_type = SGS_REJ_SFCAP_1;
125 					rej->rej_str =
126 					    conv_cap_val_sf1(SF1_SUNW_ADDR32,
127 					    M_MACH, 0, &cap_buf);
128 					return (0);
129 				}
130 			}
131 #endif
132 		}
133 	}
134 	return (1);
135 }
136 
137 static void
138 remove_fdesc(Fdesc *fdp)
139 {
140 #if	defined(MAP_ALIGN)
141 	if (fdp->fd_fmap.fm_maddr &&
142 	    ((fdp->fd_fmap.fm_mflags & MAP_ALIGN) == 0)) {
143 #else
144 	if (fdp->fd_fmap.fm_maddr) {
145 #endif
146 		(void) munmap(fdp->fd_fmap.fm_maddr, fdp->fd_fmap.fm_msize);
147 
148 		/*
149 		 * Note, this file descriptor might be duplicating information
150 		 * from the global fmap descriptor.  If so, clean up the global
151 		 * descriptor to prevent a duplicate (unnecessary) unmap.
152 		 */
153 		if (fmap->fm_maddr == fdp->fd_fmap.fm_maddr) {
154 			fmap->fm_maddr = 0;
155 			fmap_setup();
156 		}
157 	}
158 	if (fdp->fd_fd)
159 		(void) close(fdp->fd_fd);
160 	if (fdp->fd_pname && (fdp->fd_pname != fdp->fd_nname))
161 		free((void *)fdp->fd_pname);
162 	if (fdp->fd_nname)
163 		free((void *)fdp->fd_nname);
164 }
165 
166 /*
167  * When $HWCAP is used to represent dependencies, take the associated directory
168  * and analyze all the files it contains.
169  */
170 static int
171 hwcap_dir(Alist **fdalpp, Lm_list *lml, const char *name, Rt_map *clmp,
172     uint_t flags, Rej_desc *rej, int *in_nfavl)
173 {
174 	char		path[PATH_MAX], *dst;
175 	const char	*src;
176 	DIR		*dir;
177 	struct dirent	*dirent;
178 	Aliste		idx;
179 	Alist		*fdalp = NULL;
180 	Fdesc		*fdp;
181 	int		error = 0;
182 
183 	/*
184 	 * Access the directory in preparation for reading its entries.  If
185 	 * successful, establish the initial pathname.
186 	 */
187 	if ((dir = opendir(name)) == 0) {
188 		Rej_desc	_rej = { 0 };
189 
190 		_rej.rej_type = SGS_REJ_STR;
191 		_rej.rej_name = name;
192 		_rej.rej_str = strerror(errno);
193 		DBG_CALL(Dbg_file_rejected(lml, &_rej, M_MACH));
194 		rejection_inherit(rej, &_rej);
195 		return (0);
196 	}
197 
198 	for (dst = path, src = name; *src; dst++, src++)
199 		*dst = *src;
200 	*dst++ = '/';
201 
202 	/*
203 	 * Read each entry from the directory and determine whether it is a
204 	 * valid ELF file.
205 	 */
206 	while ((dirent = readdir(dir)) != NULL) {
207 		const char	*file = dirent->d_name, *oname;
208 		char		*_dst;
209 		Fdesc		fdesc = { 0 };
210 		Rej_desc	_rej = { 0 };
211 
212 		/*
213 		 * Ignore "." and ".." entries.
214 		 */
215 		if ((file[0] == '.') && ((file[1] == '\0') ||
216 		    ((file[1] == '.') && (file[2] == '\0'))))
217 			continue;
218 
219 		/*
220 		 * Complete the full pathname, and verify its usability.  Note,
221 		 * an auditor can supply an alternative name.
222 		 */
223 		for (_dst = dst, src = file, file = dst; *src; _dst++, src++)
224 			*_dst = *src;
225 		*_dst = '\0';
226 
227 		if ((oname = strdup(path)) == NULL) {
228 			error = 1;
229 			break;
230 		}
231 
232 		if (load_trace(lml, &oname, clmp) == 0) {
233 			free((void *)oname);
234 			continue;
235 		}
236 		name = oname;
237 
238 		/*
239 		 * Note, all directory entries are processed by find_path(),
240 		 * even entries that are directories themselves.  This single
241 		 * point for control keeps the number of stat()'s down, and
242 		 * provides a single point for error diagnostics.
243 		 */
244 		if (find_path(lml, name, clmp, flags, &fdesc,
245 		    &_rej, in_nfavl) == 0) {
246 			rejection_inherit(rej, &_rej);
247 			if ((rej->rej_name != _rej.rej_name) &&
248 			    (_rej.rej_name == name))
249 				free((void *)name);
250 			continue;
251 		}
252 
253 		DBG_CALL(Dbg_cap_hw_candidate(lml, name));
254 
255 		/*
256 		 * If this object has already been loaded, obtain the hardware
257 		 * capabilities for later sorting.  Otherwise we have a new
258 		 * candidate.
259 		 */
260 		if (fdesc.fd_lmp)
261 			fdesc.fd_fmap.fm_hwptr = HWCAP(fdesc.fd_lmp);
262 		else
263 			fdesc.fd_fmap = *fmap;
264 
265 		if (alist_append(&fdalp, &fdesc, sizeof (Fdesc), 10) == 0) {
266 			remove_fdesc(&fdesc);
267 			error = 1;
268 			break;
269 		}
270 
271 		/*
272 		 * Clear the global file mapping structure so that the mapping
273 		 * for this file won't be overriden.
274 		 */
275 		fmap->fm_mflags = MAP_PRIVATE;
276 		fmap->fm_maddr = 0;
277 		fmap->fm_msize = FMAP_SIZE;
278 		fmap->fm_hwptr = 0;
279 	}
280 	(void) closedir(dir);
281 
282 	/*
283 	 * If no objects have been found, we're done.  Also, if an allocation
284 	 * error occurred while processing any object, remove any objects that
285 	 * had already been added to the list and return.
286 	 */
287 	if ((fdalp == NULL) || error) {
288 		if (fdalp) {
289 			for (ALIST_TRAVERSE(fdalp, idx, fdp))
290 				remove_fdesc(fdp);
291 			free(fdalp);
292 		}
293 		return (0);
294 	}
295 
296 	/*
297 	 * Having processed and retained all candidates from this directory,
298 	 * sort them, based on the precedence of their hardware capabilities.
299 	 */
300 	qsort(fdalp->al_data, fdalp->al_nitems, fdalp->al_size, compare);
301 
302 	*fdalpp = fdalp;
303 	return (1);
304 }
305 
306 static Pnode *
307 _hwcap_filtees(Pnode **pnpp, Aliste nlmco, Lm_cntl *nlmc, Rt_map *flmp,
308     const char *ref, const char *dir, int mode, uint_t flags, int *in_nfavl)
309 {
310 	Alist		*fdalp = NULL;
311 	Aliste		idx;
312 	Pnode		*fpnp = 0, *lpnp, *npnp = (*pnpp)->p_next;
313 	Fdesc		*fdp;
314 	Lm_list		*lml = LIST(flmp);
315 	int		unused = 0;
316 	Rej_desc	rej = { 0 };
317 
318 	if (hwcap_dir(&fdalp, lml, dir, flmp, flags, &rej, in_nfavl) == 0) {
319 		remove_rej(&rej);
320 		return (0);
321 	}
322 
323 	/*
324 	 * Now complete the mapping of each of the ordered objects, adding
325 	 * each object to a new Pnode.
326 	 */
327 	for (ALIST_TRAVERSE(fdalp, idx, fdp)) {
328 		Rt_map	*nlmp;
329 		Grp_hdl	*ghp = 0;
330 		Pnode	*pnp;
331 		int	audit = 0;
332 
333 		if (unused) {
334 			/*
335 			 * Flush out objects remaining.
336 			 */
337 			remove_fdesc(fdp);
338 			continue;
339 		}
340 
341 		/*
342 		 * Complete mapping the file, obtaining a handle, and continue
343 		 * to analyze the object, establishing dependencies and
344 		 * relocating.  Remove the file descriptor at this point, as it
345 		 * is no longer required.
346 		 */
347 		DBG_CALL(Dbg_file_filtee(lml, NAME(flmp), fdp->fd_nname, 0));
348 
349 		nlmp = load_path(lml, nlmco, &fdp->fd_nname, flmp, mode,
350 		    (flags | FLG_RT_HANDLE), &ghp, fdp, &rej, in_nfavl);
351 		remove_fdesc(fdp);
352 		if (nlmp == 0)
353 			continue;
354 
355 		/*
356 		 * Create a new Pnode to represent this filtee, and substitute
357 		 * the calling Pnode (which was used to represent the hardware
358 		 * capability directory).
359 		 */
360 		if ((pnp = calloc(1, sizeof (Pnode))) == 0) {
361 			if (ghp) {
362 				remove_lmc(lml, flmp, nlmc, nlmco,
363 				    fdp->fd_nname);
364 			}
365 			return (0);
366 		}
367 		if ((pnp->p_name = strdup(NAME(nlmp))) == NULL) {
368 			if (ghp) {
369 				remove_lmc(lml, flmp, nlmc, nlmco,
370 				    fdp->fd_nname);
371 			}
372 			free(pnp);
373 			return (0);
374 		}
375 		pnp->p_len = strlen(NAME(nlmp));
376 		pnp->p_info = (void *)ghp;
377 		pnp->p_next = npnp;
378 
379 		if (fpnp == 0) {
380 			Pnode	*opnp = (*pnpp);
381 
382 			/*
383 			 * If this is the first pnode, reuse the original after
384 			 * freeing any of its pathnames.
385 			 */
386 			if (opnp->p_name)
387 				free((void *)opnp->p_name);
388 			if (opnp->p_oname)
389 				free((void *)opnp->p_oname);
390 			*opnp = *pnp;
391 			free((void *)pnp);
392 			fpnp = lpnp = pnp = opnp;
393 		} else {
394 			lpnp->p_next = pnp;
395 			lpnp = pnp;
396 		}
397 
398 		/*
399 		 * Establish the filter handle to prevent any recursion.
400 		 */
401 		if (nlmp && ghp) {
402 			ghp->gh_flags |= GPH_FILTEE;
403 			pnp->p_info = (void *)ghp;
404 		}
405 
406 		/*
407 		 * Audit the filter/filtee established.  A return of 0
408 		 * indicates the auditor wishes to ignore this filtee.
409 		 */
410 		if (nlmp && (lml->lm_tflags | FLAGS1(flmp)) &
411 		    LML_TFLG_AUD_OBJFILTER) {
412 			if (audit_objfilter(flmp, ref, nlmp, 0) == 0) {
413 				audit = 1;
414 				nlmp = 0;
415 			}
416 		}
417 
418 		/*
419 		 * Finish processing the objects associated with this request.
420 		 */
421 		if (nlmp && ghp &&
422 		    ((analyze_lmc(lml, nlmco, nlmp, in_nfavl) == 0) ||
423 		    (relocate_lmc(lml, nlmco, flmp, nlmp, in_nfavl) == 0)))
424 			nlmp = 0;
425 
426 		/*
427 		 * If the filtee has been successfully processed, then create
428 		 * an association between the filter and the filtee.  This
429 		 * association provides sufficient information to tear down the
430 		 * filter and filtee if necessary.
431 		 */
432 		DBG_CALL(Dbg_file_hdl_title(DBG_HDL_ADD));
433 		if (nlmp && ghp && (hdl_add(ghp, flmp, GPD_FILTER) == 0))
434 			nlmp = 0;
435 
436 		/*
437 		 * If this object is marked an end-filtee, we're done.
438 		 */
439 		if (nlmp && ghp && (FLAGS1(nlmp) & FL1_RT_ENDFILTE))
440 			unused = 1;
441 
442 		/*
443 		 * If this filtee loading has failed, generate a diagnostic.
444 		 * Null out the pnode entry, and continue the search.
445 		 */
446 		if (nlmp == 0) {
447 			/*
448 			 * If attempting to load this filtee required a new
449 			 * link-map control list to which this request has
450 			 * added objects, then remove all the objects that
451 			 * have been associated to this request.
452 			 */
453 			if (nlmc && nlmc->lc_head)
454 				remove_lmc(lml, flmp, nlmc, nlmco, pnp->p_name);
455 
456 			DBG_CALL(Dbg_file_filtee(lml, 0, pnp->p_name, audit));
457 
458 			pnp->p_len = 0;
459 			pnp->p_info = 0;
460 		}
461 	}
462 
463 	free(fdalp);
464 	return (fpnp);
465 }
466 
467 Pnode *
468 hwcap_filtees(Pnode **pnpp, Aliste nlmco, Lm_cntl *nlmc, Dyninfo *dip,
469     Rt_map *flmp, const char *ref, int mode, uint_t flags, int *in_nfavl)
470 {
471 	Pnode		*pnp = *pnpp;
472 	const char	*dir = pnp->p_name;
473 	Lm_list		*flml = LIST(flmp);
474 
475 	DBG_CALL(Dbg_cap_hw_filter(flml, dir, flmp));
476 
477 	if ((pnp = _hwcap_filtees(pnpp, nlmco, nlmc, flmp, ref, dir, mode,
478 	    flags, in_nfavl)) != 0)
479 		return (pnp);
480 
481 	/*
482 	 * If no hardware capability filtees have been found, provide suitable
483 	 * diagnostics and mark the incoming Pnode as unused.
484 	 */
485 	if ((flml->lm_flags & LML_FLG_TRC_ENABLE) &&
486 	    (dip->di_flags & FLG_DI_AUXFLTR) && (rtld_flags & RT_FL_WARNFLTR))
487 		(void) printf(MSG_INTL(MSG_LDD_HWCAP_NFOUND), dir);
488 
489 	DBG_CALL(Dbg_cap_hw_filter(flml, dir, 0));
490 
491 	pnp = *pnpp;
492 	pnp->p_len = 0;
493 	return (pnp);
494 }
495 
496 /*
497  * Load an individual hardware capabilities object.
498  */
499 Rt_map *
500 load_hwcap(Lm_list *lml, Aliste lmco, const char *dir, Rt_map *clmp,
501     uint_t mode, uint_t flags, Grp_hdl **hdl, Rej_desc *rej, int *in_nfavl)
502 {
503 	Alist		*fdalp = NULL;
504 	Aliste		idx;
505 	Fdesc		*fdp;
506 	int		found = 0;
507 	Rt_map		*lmp = 0;
508 
509 	/*
510 	 * Obtain the sorted list of hardware capabilites objects available.
511 	 */
512 	if (hwcap_dir(&fdalp, lml, dir, clmp, flags, rej, in_nfavl) == 0)
513 		return (0);
514 
515 	/*
516 	 * From the list of hardware capability objects, use the first and
517 	 * discard the rest.
518 	 */
519 	for (ALIST_TRAVERSE(fdalp, idx, fdp)) {
520 		if ((found == 0) && ((lmp = load_path(lml, lmco, &fdp->fd_nname,
521 		    clmp, mode, flags, hdl, fdp, rej, in_nfavl)) != 0))
522 			found++;
523 
524 		/*
525 		 * Remove the used file descriptor and any objects remaining.
526 		 */
527 		remove_fdesc(fdp);
528 	}
529 
530 	free(fdalp);
531 	return (lmp);
532 }
533