xref: /illumos-gate/usr/src/cmd/sgs/rtld/common/cap.c (revision d1a180b0452ce86577a43be3245d2eacdeec1a34)
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, Version 1.0 only
6  * (the "License").  You may not use this file except in compliance
7  * with the License.
8  *
9  * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
10  * or http://www.opensolaris.org/os/licensing.
11  * See the License for the specific language governing permissions
12  * and limitations under the License.
13  *
14  * When distributing Covered Code, include this CDDL HEADER in each
15  * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
16  * If applicable, add the following below this CDDL HEADER, with the
17  * fields enclosed by brackets "[]" replaced with your own identifying
18  * information: Portions Copyright [yyyy] [name of copyright owner]
19  *
20  * CDDL HEADER END
21  */
22 /*
23  * Copyright 2005 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	<string.h>
35 #include	<limits.h>
36 #include	"conv.h"
37 #include	"_rtld.h"
38 #include	"_audit.h"
39 #include	"_elf.h"
40 #include	"msg.h"
41 #include	"debug.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_hwcap_1_str(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 		 * Note, this file descriptor might be duplicating information
122 		 * from the global fmap descriptor.  If so, clean up the global
123 		 * descriptor to prevent a duplicate (unnecessary) unmap.
124 		 */
125 		if (fmap->fm_maddr == fdp->fd_fmap.fm_maddr)
126 			fmap->fm_maddr = 0;
127 	}
128 	if (fdp->fd_fd)
129 		(void) close(fdp->fd_fd);
130 	if (fdp->fd_pname && (fdp->fd_pname != fdp->fd_nname))
131 		free((void *)fdp->fd_pname);
132 	if (fdp->fd_nname)
133 		free((void *)fdp->fd_nname);
134 }
135 
136 /*
137  * When $HWCAP is used to represent dependencies, take the associated directory
138  * and analyze all the files it contains.
139  */
140 int
141 hwcap_dir(Alist ** fdalpp, Lm_list * lml, const char *name, Rt_map * clmp,
142     uint_t flags, Rej_desc *rej)
143 {
144 	char		path[PATH_MAX], *dst;
145 	const char	*src;
146 	DIR		*dir;
147 	struct dirent	*dirent;
148 	Aliste		off;
149 	Alist		*fdalp = 0;
150 	Fdesc		*fdp;
151 	int		error = 0;
152 
153 	/*
154 	 * Access the directory in preparation for reading its entries.  If
155 	 * successful, establish the initial pathname.
156 	 */
157 	if ((dir = opendir(name)) == 0) {
158 		Rej_desc	_rej = { 0 };
159 
160 		_rej.rej_type = SGS_REJ_STR;
161 		_rej.rej_name = name;
162 		_rej.rej_str = strerror(errno);
163 		DBG_CALL(Dbg_file_rejected(&_rej));
164 		rejection_inherit(rej, &_rej, 0);
165 		return (0);
166 	}
167 
168 	for (dst = path, src = name; *src; dst++, src++)
169 		*dst = *src;
170 	*dst++ = '/';
171 
172 	/*
173 	 * Read each entry from the directory and determine whether it is a
174 	 * valid ELF file.
175 	 */
176 	while ((dirent = readdir(dir)) != NULL) {
177 		const char	*file = dirent->d_name;
178 		char		*_dst;
179 		Fdesc		fdesc = { 0 };
180 		Rej_desc	_rej = { 0 };
181 
182 		/*
183 		 * Ignore "." and ".." entries.
184 		 */
185 		if ((file[0] == '.') && ((file[1] == '\0') ||
186 		    ((file[1] == '.') && (file[2] == '\0'))))
187 			continue;
188 
189 		/*
190 		 * Complete the full pathname, and verify its usability.
191 		 */
192 		for (_dst = dst, src = file, file = dst; *src; _dst++, src++)
193 			*_dst = *src;
194 		*_dst = '\0';
195 
196 		if ((name = strdup(path)) == 0) {
197 			error = 1;
198 			break;
199 		}
200 		if ((name = load_trace(lml, name, clmp)) == 0)
201 			continue;
202 
203 		if (find_path(lml, name, clmp, flags, &fdesc, &_rej) == 0)
204 			rejection_inherit(rej, &_rej, &fdesc);
205 		else {
206 			DBG_CALL(Dbg_cap_hw_candidate(name));
207 
208 			/*
209 			 * If this object has already been loaded, obtain the
210 			 * hardware capabilities for later sorting.  Otherwise
211 			 * we have a new candidate.
212 			 */
213 			if (fdesc.fd_lmp)
214 				fdesc.fd_fmap.fm_hwptr = HWCAP(fdesc.fd_lmp);
215 			else
216 				fdesc.fd_fmap = *fmap;
217 
218 			if (alist_append(&fdalp, &fdesc,
219 			    sizeof (Fdesc), 10) == 0) {
220 				remove_fdesc(&fdesc);
221 				error = 1;
222 				break;
223 			}
224 		}
225 
226 		/*
227 		 * Clear the global file mapping structure so that the mapping
228 		 * for this file won't be overriden.
229 		 */
230 		fmap->fm_mflags = MAP_PRIVATE;
231 		fmap->fm_maddr = 0;
232 		fmap->fm_msize = syspagsz;
233 		fmap->fm_hwptr = 0;
234 
235 	}
236 	(void) closedir(dir);
237 
238 	/*
239 	 * If no objects have been found, we're done.  Also, if an allocation
240 	 * error occurred while processing any object, remove any objects that
241 	 * had already been added to the list and return.
242 	 */
243 	if ((fdalp == 0) || error) {
244 		if (fdalp) {
245 			for (ALIST_TRAVERSE(fdalp, off, fdp))
246 				remove_fdesc(fdp);
247 			free(fdalp);
248 		}
249 		return (0);
250 	}
251 
252 	/*
253 	 * Having processed and retained all candidates from this directory,
254 	 * sort them, based on the precedence of their hardware capabilities.
255 	 */
256 	qsort(&(fdalp->al_data[0]), ((fdalp->al_next - (sizeof (Alist) -
257 	    sizeof (void *))) / fdalp->al_size), fdalp->al_size, compare);
258 
259 	*fdalpp = fdalp;
260 	return (1);
261 }
262 
263 static Pnode *
264 _hwcap_filtees(Pnode ** pnpp, Aliste nlmco, Rt_map * flmp, const char *ref,
265     const char *dir, int mode, uint_t flags)
266 {
267 	Alist		*fdalp = 0;
268 	Aliste		off;
269 	Pnode		*fpnp = 0, *lpnp, *npnp = (*pnpp)->p_next;
270 	Fdesc		*fdp;
271 	Lm_list		*lml = LIST(flmp);
272 	int		unused = 0;
273 	Rej_desc	rej = { 0 };
274 
275 	if (hwcap_dir(&fdalp, lml, dir, flmp, flags, &rej) == 0) {
276 		remove_rej(&rej);
277 		return (0);
278 	}
279 
280 	/*
281 	 * Now complete the mapping of each of the ordered objects, adding
282 	 * each object to a new Pnode.
283 	 */
284 	for (ALIST_TRAVERSE(fdalp, off, fdp)) {
285 		Rt_map	*nlmp;
286 		Grp_hdl	*ghp;
287 		Pnode	*pnp;
288 
289 		if (unused) {
290 			/*
291 			 * Flush out objects remaining.
292 			 */
293 			remove_fdesc(fdp);
294 			continue;
295 		}
296 
297 		/*
298 		 * Complete mapping the file, obtaining a handle, and continue
299 		 * to analyze the object, establishing dependencies and
300 		 * relocating.  Remove the file descriptor at this point, as it
301 		 * is no longer required.
302 		 */
303 		DBG_CALL(Dbg_file_filtee(NAME(flmp), fdp->fd_nname, 0));
304 
305 		nlmp = load_path(lml, nlmco, fdp->fd_nname, flmp, mode,
306 		    (flags | FLG_RT_HANDLE), &ghp, fdp, &rej);
307 		remove_fdesc(fdp);
308 
309 		if (nlmp == 0)
310 			continue;
311 
312 		/*
313 		 * Audit the filter/filtee established.  A return of 0
314 		 * indicates the auditor wishes to ignore this filtee.
315 		 */
316 		if ((lml->lm_tflags | FLAGS1(flmp)) &
317 		    LML_TFLG_AUD_OBJFILTER) {
318 			if (audit_objfilter(flmp, ref, nlmp, 0) == 0) {
319 				DBG_CALL(Dbg_file_filtee(0, NAME(nlmp), 1));
320 				(void) dlclose_core(ghp, flmp);
321 				continue;
322 			}
323 		}
324 
325 		ghp->gh_flags |= GPH_FILTEE;
326 
327 		/*
328 		 * Finish processing the objects associated with this request.
329 		 */
330 		if ((analyze_lmc(lml, nlmco, nlmp) == 0) ||
331 		    (relocate_lmc(lml, nlmco, nlmp) == 0)) {
332 			(void) dlclose_core(ghp, flmp);
333 			continue;
334 		}
335 
336 		/*
337 		 * Create a new Pnode to represent this filtee, and substitute
338 		 * the calling Pnode (which was used to represent the hardware
339 		 * capability directory).
340 		 */
341 		if ((pnp = calloc(1, sizeof (Pnode))) == 0) {
342 			(void) dlclose_core(ghp, flmp);
343 			continue;
344 		}
345 		if ((pnp->p_name = strdup(NAME(nlmp))) == 0) {
346 			(void) dlclose_core(ghp, flmp);
347 			free(pnp);
348 			continue;
349 		}
350 		pnp->p_len = strlen(NAME(nlmp));
351 		pnp->p_info = (void *)ghp;
352 		pnp->p_next = npnp;
353 
354 		/*
355 		 * Finally, if the filtee is part of a link-map control list
356 		 * that is equivalent, or less, than the filter control list,
357 		 * create an association between the filter and filtee.  This
358 		 * association provides sufficient information to tear down the
359 		 * filter and filtee if necessary.
360 		 */
361 		if ((CNTL(nlmp) <= CNTL(flmp)) &&
362 		    (hdl_add(ghp, flmp, GPD_FILTER) == 0)) {
363 			(void) dlclose_core(ghp, flmp);
364 			free((void *)pnp->p_name);
365 			free(pnp);
366 			continue;
367 		}
368 
369 		if (fpnp == 0) {
370 			Pnode	*opnp = (*pnpp);
371 			/*
372 			 * If this is the first pnode, reuse the original after
373 			 * freeing any of its pathnames.
374 			 */
375 			if (opnp->p_name)
376 				free((void *)opnp->p_name);
377 			if (opnp->p_oname)
378 				free((void *)opnp->p_oname);
379 			*opnp = *pnp;
380 			free((void *)pnp);
381 			fpnp = lpnp = opnp;
382 		} else {
383 			lpnp->p_next = pnp;
384 			lpnp = pnp;
385 		}
386 
387 		/*
388 		 * If this object is marked an end-filtee, we're done.
389 		 */
390 		if (FLAGS1(nlmp) & FL1_RT_ENDFILTE)
391 			unused = 1;
392 	}
393 
394 	free(fdalp);
395 	return (fpnp);
396 }
397 
398 Pnode *
399 hwcap_filtees(Pnode ** pnpp, Aliste nlmco, Dyninfo * dip, Rt_map * flmp,
400     const char *ref, int mode, uint_t flags)
401 {
402 	Pnode		*pnp = *pnpp;
403 	const char	*dir = pnp->p_name;
404 
405 	DBG_CALL(Dbg_cap_hw_filter(dir, NAME(flmp)));
406 
407 	if ((pnp = _hwcap_filtees(pnpp, nlmco, flmp, ref, dir, mode,
408 	    flags)) != 0)
409 		return (pnp);
410 
411 	/*
412 	 * If no hardware capability filtees have been found, provide suitable
413 	 * diagnostics and mark the incoming Pnode as unused.
414 	 */
415 	if ((LIST(flmp)->lm_flags & LML_FLG_TRC_ENABLE) &&
416 	    (dip->di_flags & FLG_DI_AUXFLTR) && (rtld_flags & RT_FL_WARNFLTR))
417 		(void) printf(MSG_INTL(MSG_LDD_HWCAP_NFOUND), dir);
418 
419 	DBG_CALL(Dbg_cap_hw_filter(dir, 0));
420 
421 	pnp = *pnpp;
422 	pnp->p_len = 0;
423 	return (pnp);
424 }
425 
426 /*
427  * Load an individual hardware capabilities object.
428  */
429 Rt_map *
430 load_hwcap(Lm_list * lml, Aliste lmco, const char *dir, Rt_map * clmp,
431     uint_t mode, uint_t flags, Grp_hdl ** hdl, Rej_desc *rej)
432 {
433 	Alist		*fdalp = 0;
434 	Aliste		off;
435 	Fdesc		*fdp;
436 	int		found = 0;
437 	Rt_map		*lmp = 0;
438 
439 	/*
440 	 * Obtain the sorted list of hardware capabilites objects available.
441 	 */
442 	if (hwcap_dir(&fdalp, lml, dir, clmp, flags, rej) == 0)
443 		return (0);
444 
445 	/*
446 	 * From the list of hardware capability objects, use the first and
447 	 * discard the rest.
448 	 */
449 	for (ALIST_TRAVERSE(fdalp, off, fdp)) {
450 		if ((found == 0) && ((lmp = load_path(lml, lmco, fdp->fd_nname,
451 		    clmp, mode, flags, hdl, fdp, rej)) != 0))
452 			found++;
453 
454 		/*
455 		 * Remove the used file descriptor and any objects remaining.
456 		 */
457 		remove_fdesc(fdp);
458 	}
459 
460 	free(fdalp);
461 	return (lmp);
462 }
463