xref: /titanic_41/usr/src/cmd/sgs/rtld/common/cap.c (revision f48205be61a214698b763ff550ab9e657525104c)
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 2007 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 			rej->rej_type = SGS_REJ_HWCAP_1;
97 			rej->rej_str = conv_cap_val_hw1(val, M_MACH);
98 			return (0);
99 		}
100 
101 		/*
102 		 * Retain this hardware capabilities pointer for possible later
103 		 * inspection should this object be processed as a filtee.
104 		 */
105 		fmap->fm_hwptr = cptr->c_un.c_val;
106 	}
107 	return (1);
108 }
109 
110 static void
111 remove_fdesc(Fdesc *fdp)
112 {
113 #if	defined(MAP_ALIGN)
114 	if (fdp->fd_fmap.fm_maddr &&
115 	    ((fdp->fd_fmap.fm_mflags & MAP_ALIGN) == 0)) {
116 #else
117 	if (fdp->fd_fmap.fm_maddr) {
118 #endif
119 		(void) munmap(fdp->fd_fmap.fm_maddr, fdp->fd_fmap.fm_msize);
120 
121 		/*
122 		 * Note, this file descriptor might be duplicating information
123 		 * from the global fmap descriptor.  If so, clean up the global
124 		 * descriptor to prevent a duplicate (unnecessary) unmap.
125 		 */
126 		if (fmap->fm_maddr == fdp->fd_fmap.fm_maddr) {
127 			fmap->fm_maddr = 0;
128 			fmap_setup();
129 		}
130 	}
131 	if (fdp->fd_fd)
132 		(void) close(fdp->fd_fd);
133 	if (fdp->fd_pname && (fdp->fd_pname != fdp->fd_nname))
134 		free((void *)fdp->fd_pname);
135 	if (fdp->fd_nname)
136 		free((void *)fdp->fd_nname);
137 }
138 
139 /*
140  * When $HWCAP is used to represent dependencies, take the associated directory
141  * and analyze all the files it contains.
142  */
143 int
144 hwcap_dir(Alist **fdalpp, Lm_list *lml, const char *name, Rt_map *clmp,
145     uint_t flags, Rej_desc *rej)
146 {
147 	char		path[PATH_MAX], *dst;
148 	const char	*src;
149 	DIR		*dir;
150 	struct dirent	*dirent;
151 	Aliste		off;
152 	Alist		*fdalp = 0;
153 	Fdesc		*fdp;
154 	int		error = 0;
155 
156 	/*
157 	 * Access the directory in preparation for reading its entries.  If
158 	 * successful, establish the initial pathname.
159 	 */
160 	if ((dir = opendir(name)) == 0) {
161 		Rej_desc	_rej = { 0 };
162 
163 		_rej.rej_type = SGS_REJ_STR;
164 		_rej.rej_name = name;
165 		_rej.rej_str = strerror(errno);
166 		DBG_CALL(Dbg_file_rejected(lml, &_rej));
167 		rejection_inherit(rej, &_rej);
168 		return (0);
169 	}
170 
171 	for (dst = path, src = name; *src; dst++, src++)
172 		*dst = *src;
173 	*dst++ = '/';
174 
175 	/*
176 	 * Read each entry from the directory and determine whether it is a
177 	 * valid ELF file.
178 	 */
179 	while ((dirent = readdir(dir)) != NULL) {
180 		const char	*file = dirent->d_name;
181 		char		*_dst, *_name;
182 		Fdesc		fdesc = { 0 };
183 		Rej_desc	_rej = { 0 };
184 
185 		/*
186 		 * Ignore "." and ".." entries.
187 		 */
188 		if ((file[0] == '.') && ((file[1] == '\0') ||
189 		    ((file[1] == '.') && (file[2] == '\0'))))
190 			continue;
191 
192 		/*
193 		 * Complete the full pathname, and verify its usability.
194 		 */
195 		for (_dst = dst, src = file, file = dst; *src; _dst++, src++)
196 			*_dst = *src;
197 		*_dst = '\0';
198 
199 		if ((_name = strdup(path)) == NULL) {
200 			error = 1;
201 			break;
202 		}
203 
204 		if ((name = load_trace(lml, _name, clmp)) == 0) {
205 			free((void *)_name);
206 			continue;
207 		}
208 
209 		/*
210 		 * Note, all directory entries are processed by find_path(),
211 		 * even entries that are directories themselves.  This single
212 		 * point for control keeps the number of stat()'s down, and
213 		 * provides a single point for error diagnostics.
214 		 */
215 		if (find_path(lml, name, clmp, flags, &fdesc, &_rej) == 0) {
216 			rejection_inherit(rej, &_rej);
217 			if ((rej->rej_name != _rej.rej_name) &&
218 			    (_rej.rej_name == name))
219 				free((void *)name);
220 			continue;
221 		}
222 
223 		DBG_CALL(Dbg_cap_hw_candidate(lml, name));
224 
225 		/*
226 		 * If this object has already been loaded, obtain the hardware
227 		 * capabilities for later sorting.  Otherwise we have a new
228 		 * candidate.
229 		 */
230 		if (fdesc.fd_lmp)
231 			fdesc.fd_fmap.fm_hwptr = HWCAP(fdesc.fd_lmp);
232 		else
233 			fdesc.fd_fmap = *fmap;
234 
235 		if (alist_append(&fdalp, &fdesc, sizeof (Fdesc), 10) == 0) {
236 			remove_fdesc(&fdesc);
237 			error = 1;
238 			break;
239 		}
240 
241 		/*
242 		 * Clear the global file mapping structure so that the mapping
243 		 * for this file won't be overriden.
244 		 */
245 		fmap->fm_mflags = MAP_PRIVATE;
246 		fmap->fm_maddr = 0;
247 		fmap->fm_msize = syspagsz;
248 		fmap->fm_hwptr = 0;
249 	}
250 	(void) closedir(dir);
251 
252 	/*
253 	 * If no objects have been found, we're done.  Also, if an allocation
254 	 * error occurred while processing any object, remove any objects that
255 	 * had already been added to the list and return.
256 	 */
257 	if ((fdalp == 0) || error) {
258 		if (fdalp) {
259 			for (ALIST_TRAVERSE(fdalp, off, fdp))
260 				remove_fdesc(fdp);
261 			free(fdalp);
262 		}
263 		return (0);
264 	}
265 
266 	/*
267 	 * Having processed and retained all candidates from this directory,
268 	 * sort them, based on the precedence of their hardware capabilities.
269 	 */
270 	qsort(&(fdalp->al_data[0]), ((fdalp->al_next - (sizeof (Alist) -
271 	    sizeof (void *))) / fdalp->al_size), fdalp->al_size, compare);
272 
273 	*fdalpp = fdalp;
274 	return (1);
275 }
276 
277 static Pnode *
278 _hwcap_filtees(Pnode **pnpp, Aliste nlmco, Lm_cntl *nlmc, Rt_map *flmp,
279     const char *ref, const char *dir, int mode, uint_t flags)
280 {
281 	Alist		*fdalp = 0;
282 	Aliste		off;
283 	Pnode		*fpnp = 0, *lpnp, *npnp = (*pnpp)->p_next;
284 	Fdesc		*fdp;
285 	Lm_list		*lml = LIST(flmp);
286 	int		unused = 0;
287 	Rej_desc	rej = { 0 };
288 
289 	if (hwcap_dir(&fdalp, lml, dir, flmp, flags, &rej) == 0) {
290 		remove_rej(&rej);
291 		return (0);
292 	}
293 
294 	/*
295 	 * Now complete the mapping of each of the ordered objects, adding
296 	 * each object to a new Pnode.
297 	 */
298 	for (ALIST_TRAVERSE(fdalp, off, fdp)) {
299 		Rt_map	*nlmp;
300 		Grp_hdl	*ghp = 0;
301 		Pnode	*pnp;
302 		int	audit = 0;
303 
304 		if (unused) {
305 			/*
306 			 * Flush out objects remaining.
307 			 */
308 			remove_fdesc(fdp);
309 			continue;
310 		}
311 
312 		/*
313 		 * Complete mapping the file, obtaining a handle, and continue
314 		 * to analyze the object, establishing dependencies and
315 		 * relocating.  Remove the file descriptor at this point, as it
316 		 * is no longer required.
317 		 */
318 		DBG_CALL(Dbg_file_filtee(lml, NAME(flmp), fdp->fd_nname, 0));
319 
320 		nlmp = load_path(lml, nlmco, fdp->fd_nname, flmp, mode,
321 		    (flags | FLG_RT_HANDLE), &ghp, fdp, &rej);
322 		remove_fdesc(fdp);
323 		if (nlmp == 0)
324 			continue;
325 
326 		/*
327 		 * Create a new Pnode to represent this filtee, and substitute
328 		 * the calling Pnode (which was used to represent the hardware
329 		 * capability directory).
330 		 */
331 		if ((pnp = calloc(1, sizeof (Pnode))) == 0) {
332 			if (ghp) {
333 				remove_lmc(lml, flmp, nlmc, nlmco,
334 				    fdp->fd_nname);
335 			}
336 			return (0);
337 		}
338 		if ((pnp->p_name = strdup(NAME(nlmp))) == NULL) {
339 			if (ghp) {
340 				remove_lmc(lml, flmp, nlmc, nlmco,
341 				    fdp->fd_nname);
342 			}
343 			free(pnp);
344 			return (0);
345 		}
346 		pnp->p_len = strlen(NAME(nlmp));
347 		pnp->p_info = (void *)ghp;
348 		pnp->p_next = npnp;
349 
350 		if (fpnp == 0) {
351 			Pnode	*opnp = (*pnpp);
352 
353 			/*
354 			 * If this is the first pnode, reuse the original after
355 			 * freeing any of its pathnames.
356 			 */
357 			if (opnp->p_name)
358 				free((void *)opnp->p_name);
359 			if (opnp->p_oname)
360 				free((void *)opnp->p_oname);
361 			*opnp = *pnp;
362 			free((void *)pnp);
363 			fpnp = lpnp = pnp = opnp;
364 		} else {
365 			lpnp->p_next = pnp;
366 			lpnp = pnp;
367 		}
368 
369 		/*
370 		 * Establish the filter handle to prevent any recursion.
371 		 */
372 		if (nlmp && ghp) {
373 			ghp->gh_flags |= GPH_FILTEE;
374 			pnp->p_info = (void *)ghp;
375 		}
376 
377 		/*
378 		 * Audit the filter/filtee established.  A return of 0
379 		 * indicates the auditor wishes to ignore this filtee.
380 		 */
381 		if (nlmp && (lml->lm_tflags | FLAGS1(flmp)) &
382 		    LML_TFLG_AUD_OBJFILTER) {
383 			if (audit_objfilter(flmp, ref, nlmp, 0) == 0) {
384 				audit = 1;
385 				nlmp = 0;
386 			}
387 		}
388 
389 		/*
390 		 * Finish processing the objects associated with this request.
391 		 */
392 		if (nlmp && ghp && ((analyze_lmc(lml, nlmco, nlmp) == 0) ||
393 		    (relocate_lmc(lml, nlmco, flmp, nlmp) == 0)))
394 			nlmp = 0;
395 
396 		/*
397 		 * If the filtee has been successfully processed, then create
398 		 * an association between the filter and the filtee.  This
399 		 * association provides sufficient information to tear down the
400 		 * filter and filtee if necessary.
401 		 */
402 		DBG_CALL(Dbg_file_hdl_title(DBG_DEP_ADD));
403 		if (nlmp && ghp && (hdl_add(ghp, flmp, GPD_FILTER) == 0))
404 			nlmp = 0;
405 
406 		/*
407 		 * If this object is marked an end-filtee, we're done.
408 		 */
409 		if (nlmp && ghp && (FLAGS1(nlmp) & FL1_RT_ENDFILTE))
410 			unused = 1;
411 
412 		/*
413 		 * If this filtee loading has failed, generate a diagnostic.
414 		 * Null out the pnode entry, and continue the search.
415 		 */
416 		if (nlmp == 0) {
417 			/*
418 			 * If attempting to load this filtee required a new
419 			 * link-map control list to which this request has
420 			 * added objects, then remove all the objects that
421 			 * have been associated to this request.
422 			 */
423 			if (nlmc && nlmc->lc_head)
424 				remove_lmc(lml, flmp, nlmc, nlmco, pnp->p_name);
425 
426 			DBG_CALL(Dbg_file_filtee(lml, 0, pnp->p_name, audit));
427 
428 			pnp->p_len = 0;
429 			pnp->p_info = 0;
430 		}
431 	}
432 
433 	free(fdalp);
434 	return (fpnp);
435 }
436 
437 Pnode *
438 hwcap_filtees(Pnode **pnpp, Aliste nlmco, Lm_cntl *nlmc, Dyninfo *dip,
439     Rt_map *flmp, const char *ref, int mode, uint_t flags)
440 {
441 	Pnode		*pnp = *pnpp;
442 	const char	*dir = pnp->p_name;
443 	Lm_list		*flml = LIST(flmp);
444 
445 	DBG_CALL(Dbg_cap_hw_filter(flml, dir, flmp));
446 
447 	if ((pnp = _hwcap_filtees(pnpp, nlmco, nlmc, flmp, ref, dir, mode,
448 	    flags)) != 0)
449 		return (pnp);
450 
451 	/*
452 	 * If no hardware capability filtees have been found, provide suitable
453 	 * diagnostics and mark the incoming Pnode as unused.
454 	 */
455 	if ((flml->lm_flags & LML_FLG_TRC_ENABLE) &&
456 	    (dip->di_flags & FLG_DI_AUXFLTR) && (rtld_flags & RT_FL_WARNFLTR))
457 		(void) printf(MSG_INTL(MSG_LDD_HWCAP_NFOUND), dir);
458 
459 	DBG_CALL(Dbg_cap_hw_filter(flml, dir, 0));
460 
461 	pnp = *pnpp;
462 	pnp->p_len = 0;
463 	return (pnp);
464 }
465 
466 /*
467  * Load an individual hardware capabilities object.
468  */
469 Rt_map *
470 load_hwcap(Lm_list *lml, Aliste lmco, const char *dir, Rt_map *clmp,
471     uint_t mode, uint_t flags, Grp_hdl **hdl, Rej_desc *rej)
472 {
473 	Alist		*fdalp = 0;
474 	Aliste		off;
475 	Fdesc		*fdp;
476 	int		found = 0;
477 	Rt_map		*lmp = 0;
478 
479 	/*
480 	 * Obtain the sorted list of hardware capabilites objects available.
481 	 */
482 	if (hwcap_dir(&fdalp, lml, dir, clmp, flags, rej) == 0)
483 		return (0);
484 
485 	/*
486 	 * From the list of hardware capability objects, use the first and
487 	 * discard the rest.
488 	 */
489 	for (ALIST_TRAVERSE(fdalp, off, fdp)) {
490 		if ((found == 0) && ((lmp = load_path(lml, lmco, fdp->fd_nname,
491 		    clmp, mode, flags, hdl, fdp, rej)) != 0))
492 			found++;
493 
494 		/*
495 		 * Remove the used file descriptor and any objects remaining.
496 		 */
497 		remove_fdesc(fdp);
498 	}
499 
500 	free(fdalp);
501 	return (lmp);
502 }
503