xref: /illumos-gate/usr/src/cmd/sgs/rtld/common/cap.c (revision 51ccf66eff01cf7e19106ce91bc35ef397259faf)
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 #pragma ident	"%Z%%M%	%I%	%E% SMI"
27 
28 #include	"_synonyms.h"
29 
30 #include	<sys/types.h>
31 #include	<sys/mman.h>
32 #include	<dirent.h>
33 #include	<stdio.h>
34 #include	<stdlib.h>
35 #include	<string.h>
36 #include	<limits.h>
37 #include	<debug.h>
38 #include	<conv.h>
39 #include	"_rtld.h"
40 #include	"_audit.h"
41 #include	"msg.h"
42 
43 /*
44  * qsort(3c) comparison function.
45  */
46 static int
47 compare(const void *fdesc1, const void *fdesc2)
48 {
49 	ulong_t	hwcap1 = ((Fdesc *)fdesc1)->fd_fmap.fm_hwptr;
50 	ulong_t	hwcap2 = ((Fdesc *)fdesc2)->fd_fmap.fm_hwptr;
51 
52 	if (hwcap1 && (hwcap2 == 0))
53 		return (-1);
54 	if ((hwcap1 == 0) && hwcap2)
55 		return (1);
56 	if ((hwcap1 == 0) && (hwcap2 == 0))
57 		return (0);
58 
59 	if (hwcap1 > hwcap2)
60 		return (-1);
61 	if (hwcap1 < hwcap2)
62 		return (1);
63 	return (0);
64 }
65 
66 /*
67  * If this object defines a set of hardware capability requirements, insure the
68  * kernal can cope with them.
69  */
70 int
71 hwcap_check(Rej_desc *rej, Ehdr *ehdr)
72 {
73 	Cap	*cptr;
74 	Phdr	*phdr;
75 	int	cnt;
76 
77 	/* LINTED */
78 	phdr = (Phdr *)((char *)ehdr + ehdr->e_phoff);
79 	for (cnt = 0; cnt < ehdr->e_phnum; cnt++, phdr++) {
80 		Lword	val;
81 
82 		if (phdr->p_type != PT_SUNWCAP)
83 			continue;
84 
85 		/* LINTED */
86 		cptr = (Cap *)((char *)ehdr + phdr->p_offset);
87 		while (cptr->c_tag != CA_SUNW_NULL) {
88 			if (cptr->c_tag == CA_SUNW_HW_1)
89 				break;
90 			cptr++;
91 		}
92 		if (cptr->c_tag == CA_SUNW_NULL)
93 			break;
94 
95 		if ((val = (cptr->c_un.c_val & ~hwcap)) != 0) {
96 			static Conv_cap_val_hw1_buf_t cap_buf;
97 
98 			rej->rej_type = SGS_REJ_HWCAP_1;
99 			rej->rej_str =
100 			    conv_cap_val_hw1(val, M_MACH, 0, &cap_buf);
101 			return (0);
102 		}
103 
104 		/*
105 		 * Retain this hardware capabilities pointer for possible later
106 		 * inspection should this object be processed as a filtee.
107 		 */
108 		fmap->fm_hwptr = cptr->c_un.c_val;
109 	}
110 	return (1);
111 }
112 
113 static void
114 remove_fdesc(Fdesc *fdp)
115 {
116 #if	defined(MAP_ALIGN)
117 	if (fdp->fd_fmap.fm_maddr &&
118 	    ((fdp->fd_fmap.fm_mflags & MAP_ALIGN) == 0)) {
119 #else
120 	if (fdp->fd_fmap.fm_maddr) {
121 #endif
122 		(void) munmap(fdp->fd_fmap.fm_maddr, fdp->fd_fmap.fm_msize);
123 
124 		/*
125 		 * Note, this file descriptor might be duplicating information
126 		 * from the global fmap descriptor.  If so, clean up the global
127 		 * descriptor to prevent a duplicate (unnecessary) unmap.
128 		 */
129 		if (fmap->fm_maddr == fdp->fd_fmap.fm_maddr) {
130 			fmap->fm_maddr = 0;
131 			fmap_setup();
132 		}
133 	}
134 	if (fdp->fd_fd)
135 		(void) close(fdp->fd_fd);
136 	if (fdp->fd_pname && (fdp->fd_pname != fdp->fd_nname))
137 		free((void *)fdp->fd_pname);
138 	if (fdp->fd_nname)
139 		free((void *)fdp->fd_nname);
140 }
141 
142 /*
143  * When $HWCAP is used to represent dependencies, take the associated directory
144  * and analyze all the files it contains.
145  */
146 static int
147 hwcap_dir(Alist **fdalpp, Lm_list *lml, const char *name, Rt_map *clmp,
148     uint_t flags, Rej_desc *rej, int *in_nfavl)
149 {
150 	char		path[PATH_MAX], *dst;
151 	const char	*src;
152 	DIR		*dir;
153 	struct dirent	*dirent;
154 	Aliste		idx;
155 	Alist		*fdalp = NULL;
156 	Fdesc		*fdp;
157 	int		error = 0;
158 
159 	/*
160 	 * Access the directory in preparation for reading its entries.  If
161 	 * successful, establish the initial pathname.
162 	 */
163 	if ((dir = opendir(name)) == 0) {
164 		Rej_desc	_rej = { 0 };
165 
166 		_rej.rej_type = SGS_REJ_STR;
167 		_rej.rej_name = name;
168 		_rej.rej_str = strerror(errno);
169 		DBG_CALL(Dbg_file_rejected(lml, &_rej, M_MACH));
170 		rejection_inherit(rej, &_rej);
171 		return (0);
172 	}
173 
174 	for (dst = path, src = name; *src; dst++, src++)
175 		*dst = *src;
176 	*dst++ = '/';
177 
178 	/*
179 	 * Read each entry from the directory and determine whether it is a
180 	 * valid ELF file.
181 	 */
182 	while ((dirent = readdir(dir)) != NULL) {
183 		const char	*file = dirent->d_name, *oname;
184 		char		*_dst;
185 		Fdesc		fdesc = { 0 };
186 		Rej_desc	_rej = { 0 };
187 
188 		/*
189 		 * Ignore "." and ".." entries.
190 		 */
191 		if ((file[0] == '.') && ((file[1] == '\0') ||
192 		    ((file[1] == '.') && (file[2] == '\0'))))
193 			continue;
194 
195 		/*
196 		 * Complete the full pathname, and verify its usability.  Note,
197 		 * an auditor can supply an alternative name.
198 		 */
199 		for (_dst = dst, src = file, file = dst; *src; _dst++, src++)
200 			*_dst = *src;
201 		*_dst = '\0';
202 
203 		if ((oname = strdup(path)) == NULL) {
204 			error = 1;
205 			break;
206 		}
207 
208 		if (load_trace(lml, &oname, clmp) == 0) {
209 			free((void *)oname);
210 			continue;
211 		}
212 		name = oname;
213 
214 		/*
215 		 * Note, all directory entries are processed by find_path(),
216 		 * even entries that are directories themselves.  This single
217 		 * point for control keeps the number of stat()'s down, and
218 		 * provides a single point for error diagnostics.
219 		 */
220 		if (find_path(lml, name, clmp, flags, &fdesc,
221 		    &_rej, in_nfavl) == 0) {
222 			rejection_inherit(rej, &_rej);
223 			if ((rej->rej_name != _rej.rej_name) &&
224 			    (_rej.rej_name == name))
225 				free((void *)name);
226 			continue;
227 		}
228 
229 		DBG_CALL(Dbg_cap_hw_candidate(lml, name));
230 
231 		/*
232 		 * If this object has already been loaded, obtain the hardware
233 		 * capabilities for later sorting.  Otherwise we have a new
234 		 * candidate.
235 		 */
236 		if (fdesc.fd_lmp)
237 			fdesc.fd_fmap.fm_hwptr = HWCAP(fdesc.fd_lmp);
238 		else
239 			fdesc.fd_fmap = *fmap;
240 
241 		if (alist_append(&fdalp, &fdesc, sizeof (Fdesc), 10) == 0) {
242 			remove_fdesc(&fdesc);
243 			error = 1;
244 			break;
245 		}
246 
247 		/*
248 		 * Clear the global file mapping structure so that the mapping
249 		 * for this file won't be overriden.
250 		 */
251 		fmap->fm_mflags = MAP_PRIVATE;
252 		fmap->fm_maddr = 0;
253 		fmap->fm_msize = FMAP_SIZE;
254 		fmap->fm_hwptr = 0;
255 	}
256 	(void) closedir(dir);
257 
258 	/*
259 	 * If no objects have been found, we're done.  Also, if an allocation
260 	 * error occurred while processing any object, remove any objects that
261 	 * had already been added to the list and return.
262 	 */
263 	if ((fdalp == NULL) || error) {
264 		if (fdalp) {
265 			for (ALIST_TRAVERSE(fdalp, idx, fdp))
266 				remove_fdesc(fdp);
267 			free(fdalp);
268 		}
269 		return (0);
270 	}
271 
272 	/*
273 	 * Having processed and retained all candidates from this directory,
274 	 * sort them, based on the precedence of their hardware capabilities.
275 	 */
276 	qsort(fdalp->al_data, fdalp->al_nitems, fdalp->al_size, compare);
277 
278 	*fdalpp = fdalp;
279 	return (1);
280 }
281 
282 static Pnode *
283 _hwcap_filtees(Pnode **pnpp, Aliste nlmco, Lm_cntl *nlmc, Rt_map *flmp,
284     const char *ref, const char *dir, int mode, uint_t flags, int *in_nfavl)
285 {
286 	Alist		*fdalp = NULL;
287 	Aliste		idx;
288 	Pnode		*fpnp = 0, *lpnp, *npnp = (*pnpp)->p_next;
289 	Fdesc		*fdp;
290 	Lm_list		*lml = LIST(flmp);
291 	int		unused = 0;
292 	Rej_desc	rej = { 0 };
293 
294 	if (hwcap_dir(&fdalp, lml, dir, flmp, flags, &rej, in_nfavl) == 0) {
295 		remove_rej(&rej);
296 		return (0);
297 	}
298 
299 	/*
300 	 * Now complete the mapping of each of the ordered objects, adding
301 	 * each object to a new Pnode.
302 	 */
303 	for (ALIST_TRAVERSE(fdalp, idx, fdp)) {
304 		Rt_map	*nlmp;
305 		Grp_hdl	*ghp = 0;
306 		Pnode	*pnp;
307 		int	audit = 0;
308 
309 		if (unused) {
310 			/*
311 			 * Flush out objects remaining.
312 			 */
313 			remove_fdesc(fdp);
314 			continue;
315 		}
316 
317 		/*
318 		 * Complete mapping the file, obtaining a handle, and continue
319 		 * to analyze the object, establishing dependencies and
320 		 * relocating.  Remove the file descriptor at this point, as it
321 		 * is no longer required.
322 		 */
323 		DBG_CALL(Dbg_file_filtee(lml, NAME(flmp), fdp->fd_nname, 0));
324 
325 		nlmp = load_path(lml, nlmco, &fdp->fd_nname, flmp, mode,
326 		    (flags | FLG_RT_HANDLE), &ghp, fdp, &rej, in_nfavl);
327 		remove_fdesc(fdp);
328 		if (nlmp == 0)
329 			continue;
330 
331 		/*
332 		 * Create a new Pnode to represent this filtee, and substitute
333 		 * the calling Pnode (which was used to represent the hardware
334 		 * capability directory).
335 		 */
336 		if ((pnp = calloc(1, sizeof (Pnode))) == 0) {
337 			if (ghp) {
338 				remove_lmc(lml, flmp, nlmc, nlmco,
339 				    fdp->fd_nname);
340 			}
341 			return (0);
342 		}
343 		if ((pnp->p_name = strdup(NAME(nlmp))) == NULL) {
344 			if (ghp) {
345 				remove_lmc(lml, flmp, nlmc, nlmco,
346 				    fdp->fd_nname);
347 			}
348 			free(pnp);
349 			return (0);
350 		}
351 		pnp->p_len = strlen(NAME(nlmp));
352 		pnp->p_info = (void *)ghp;
353 		pnp->p_next = npnp;
354 
355 		if (fpnp == 0) {
356 			Pnode	*opnp = (*pnpp);
357 
358 			/*
359 			 * If this is the first pnode, reuse the original after
360 			 * freeing any of its pathnames.
361 			 */
362 			if (opnp->p_name)
363 				free((void *)opnp->p_name);
364 			if (opnp->p_oname)
365 				free((void *)opnp->p_oname);
366 			*opnp = *pnp;
367 			free((void *)pnp);
368 			fpnp = lpnp = pnp = opnp;
369 		} else {
370 			lpnp->p_next = pnp;
371 			lpnp = pnp;
372 		}
373 
374 		/*
375 		 * Establish the filter handle to prevent any recursion.
376 		 */
377 		if (nlmp && ghp) {
378 			ghp->gh_flags |= GPH_FILTEE;
379 			pnp->p_info = (void *)ghp;
380 		}
381 
382 		/*
383 		 * Audit the filter/filtee established.  A return of 0
384 		 * indicates the auditor wishes to ignore this filtee.
385 		 */
386 		if (nlmp && (lml->lm_tflags | FLAGS1(flmp)) &
387 		    LML_TFLG_AUD_OBJFILTER) {
388 			if (audit_objfilter(flmp, ref, nlmp, 0) == 0) {
389 				audit = 1;
390 				nlmp = 0;
391 			}
392 		}
393 
394 		/*
395 		 * Finish processing the objects associated with this request.
396 		 */
397 		if (nlmp && ghp &&
398 		    ((analyze_lmc(lml, nlmco, nlmp, in_nfavl) == 0) ||
399 		    (relocate_lmc(lml, nlmco, flmp, nlmp, in_nfavl) == 0)))
400 			nlmp = 0;
401 
402 		/*
403 		 * If the filtee has been successfully processed, then create
404 		 * an association between the filter and the filtee.  This
405 		 * association provides sufficient information to tear down the
406 		 * filter and filtee if necessary.
407 		 */
408 		DBG_CALL(Dbg_file_hdl_title(DBG_HDL_ADD));
409 		if (nlmp && ghp && (hdl_add(ghp, flmp, GPD_FILTER) == 0))
410 			nlmp = 0;
411 
412 		/*
413 		 * If this object is marked an end-filtee, we're done.
414 		 */
415 		if (nlmp && ghp && (FLAGS1(nlmp) & FL1_RT_ENDFILTE))
416 			unused = 1;
417 
418 		/*
419 		 * If this filtee loading has failed, generate a diagnostic.
420 		 * Null out the pnode entry, and continue the search.
421 		 */
422 		if (nlmp == 0) {
423 			/*
424 			 * If attempting to load this filtee required a new
425 			 * link-map control list to which this request has
426 			 * added objects, then remove all the objects that
427 			 * have been associated to this request.
428 			 */
429 			if (nlmc && nlmc->lc_head)
430 				remove_lmc(lml, flmp, nlmc, nlmco, pnp->p_name);
431 
432 			DBG_CALL(Dbg_file_filtee(lml, 0, pnp->p_name, audit));
433 
434 			pnp->p_len = 0;
435 			pnp->p_info = 0;
436 		}
437 	}
438 
439 	free(fdalp);
440 	return (fpnp);
441 }
442 
443 Pnode *
444 hwcap_filtees(Pnode **pnpp, Aliste nlmco, Lm_cntl *nlmc, Dyninfo *dip,
445     Rt_map *flmp, const char *ref, int mode, uint_t flags, int *in_nfavl)
446 {
447 	Pnode		*pnp = *pnpp;
448 	const char	*dir = pnp->p_name;
449 	Lm_list		*flml = LIST(flmp);
450 
451 	DBG_CALL(Dbg_cap_hw_filter(flml, dir, flmp));
452 
453 	if ((pnp = _hwcap_filtees(pnpp, nlmco, nlmc, flmp, ref, dir, mode,
454 	    flags, in_nfavl)) != 0)
455 		return (pnp);
456 
457 	/*
458 	 * If no hardware capability filtees have been found, provide suitable
459 	 * diagnostics and mark the incoming Pnode as unused.
460 	 */
461 	if ((flml->lm_flags & LML_FLG_TRC_ENABLE) &&
462 	    (dip->di_flags & FLG_DI_AUXFLTR) && (rtld_flags & RT_FL_WARNFLTR))
463 		(void) printf(MSG_INTL(MSG_LDD_HWCAP_NFOUND), dir);
464 
465 	DBG_CALL(Dbg_cap_hw_filter(flml, dir, 0));
466 
467 	pnp = *pnpp;
468 	pnp->p_len = 0;
469 	return (pnp);
470 }
471 
472 /*
473  * Load an individual hardware capabilities object.
474  */
475 Rt_map *
476 load_hwcap(Lm_list *lml, Aliste lmco, const char *dir, Rt_map *clmp,
477     uint_t mode, uint_t flags, Grp_hdl **hdl, Rej_desc *rej, int *in_nfavl)
478 {
479 	Alist		*fdalp = NULL;
480 	Aliste		idx;
481 	Fdesc		*fdp;
482 	int		found = 0;
483 	Rt_map		*lmp = 0;
484 
485 	/*
486 	 * Obtain the sorted list of hardware capabilites objects available.
487 	 */
488 	if (hwcap_dir(&fdalp, lml, dir, clmp, flags, rej, in_nfavl) == 0)
489 		return (0);
490 
491 	/*
492 	 * From the list of hardware capability objects, use the first and
493 	 * discard the rest.
494 	 */
495 	for (ALIST_TRAVERSE(fdalp, idx, fdp)) {
496 		if ((found == 0) && ((lmp = load_path(lml, lmco, &fdp->fd_nname,
497 		    clmp, mode, flags, hdl, fdp, rej, in_nfavl)) != 0))
498 			found++;
499 
500 		/*
501 		 * Remove the used file descriptor and any objects remaining.
502 		 */
503 		remove_fdesc(fdp);
504 	}
505 
506 	free(fdalp);
507 	return (lmp);
508 }
509