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) 1992, 2010, Oracle and/or its affiliates. All rights reserved.
24 */
25
26 /*
27 * Object file dependent suport for ELF objects.
28 */
29
30 #include <sys/mman.h>
31 #include <stdio.h>
32 #include <unistd.h>
33 #include <libelf.h>
34 #include <string.h>
35 #include <dlfcn.h>
36 #include <debug.h>
37 #include <libld.h>
38 #include "_rtld.h"
39 #include "_audit.h"
40 #include "_elf.h"
41
42 static Rt_map *olmp = NULL;
43 static Alist *mpalp = NULL;
44
45 static Ehdr dehdr = { { ELFMAG0, ELFMAG1, ELFMAG2, ELFMAG3,
46 M_CLASS, M_DATA }, 0, M_MACH, EV_CURRENT };
47
48 /*
49 * Process a relocatable object. The static object link map pointer is used as
50 * a flag to determine whether a concatenation is already in progress (ie. an
51 * LD_PRELOAD may specify a list of objects). The link map returned simply
52 * specifies an `object' flag which the caller can interpret and thus call
53 * elf_obj_fini() to complete the concatenation.
54 */
55 static Rt_map *
56 elf_obj_init(Lm_list *lml, Aliste lmco, const char *oname)
57 {
58 Ofl_desc *ofl;
59 const char *name;
60 size_t lmsz;
61
62 /*
63 * Allocate the name of this object, as the original name may be
64 * associated with a data buffer that can be reused to load the
65 * dependencies needed to processes this object.
66 */
67 if ((name = stravl_insert(oname, 0, 0, 0)) == NULL)
68 return (NULL);
69
70 /*
71 * Initialize an output file descriptor and the entrance criteria.
72 */
73 if ((ofl = calloc(sizeof (Ofl_desc), 1)) == NULL)
74 return (NULL);
75
76 ofl->ofl_dehdr = &dehdr;
77
78 ofl->ofl_flags = (FLG_OF_DYNAMIC | FLG_OF_SHAROBJ | FLG_OF_STRIP);
79 ofl->ofl_flags1 = (FLG_OF1_RELDYN | FLG_OF1_TEXTOFF | FLG_OF1_MEMORY);
80 ofl->ofl_lml = lml;
81
82 /*
83 * As ent_setup() will effectively lazy load the necessary support
84 * libraries, make sure ld.so.1 is initialized for plt relocations.
85 * Then configure libld.so to process objects of the desired target
86 * type (this is the first call to libld.so, which will effectively
87 * lazyload it).
88 */
89 if ((elf_rtld_load() == 0) || (ld_init_target(lml, M_MACH) != 0)) {
90 free(ofl);
91 return (NULL);
92 }
93
94 /*
95 * Obtain a generic set of entrance criteria, and generate a link map
96 * place holder and use the ELFPRV() element to maintain the output
97 * file descriptor.
98 */
99 lmsz = S_DROUND(sizeof (Rt_map)) + sizeof (Rt_elfp);
100 if ((ld_ent_setup(ofl, syspagsz) == S_ERROR) ||
101 ((olmp = calloc(lmsz, 1)) == NULL)) {
102 free(ofl);
103 return (NULL);
104 }
105
106 DBG_CALL(Dbg_file_elf(lml, name, 0, 0, lml->lm_lmidstr, lmco));
107 FLAGS(olmp) |= FLG_RT_OBJECT;
108 ELFPRV(olmp) = (void *)ofl;
109
110 /*
111 * Initialize string tables.
112 */
113 if (ld_init_strings(ofl) == S_ERROR) {
114 free(ofl);
115 free(olmp);
116 olmp = NULL;
117 return (NULL);
118 }
119
120 /*
121 * Assign the output file name to be the initial object that got us
122 * here. This name is being used for diagnostic purposes only as we
123 * don't actually generate an output file unless debugging is enabled.
124 */
125 ofl->ofl_name = name;
126 NAME(olmp) = (char *)name;
127 LIST(olmp) = lml;
128
129 lm_append(lml, lmco, olmp);
130 return (olmp);
131 }
132
133 /*
134 * Define a structure to retain the mapping information of the original
135 * relocatable object. Typically, mmapobj(2) maps a relocatable object into one
136 * mapping. However, if padding has been enabled by a debugger, then additional
137 * padding segments may have been added. elf_obj_file() needs to know which
138 * segment is the relocatable objects data, and retain the initial segment and
139 * the associated segment number for unmapping this object later (see
140 * elf_obj_fini()). Note, even if padding is enabled, the final shared object
141 * that is created by the link-editor for this relocatable object will have no
142 * associated padding, as ld(1) has no capabilities to provide padding.
143 */
144 typedef struct {
145 mmapobj_result_t *md_mpp;
146 uint_t md_mnum;
147 } Mmap_desc;
148
149 /*
150 * Initial processing of a relocatable object. If this is the first object
151 * encountered we need to initialize some structures, then simply call the
152 * link-edit functionality to provide the initial processing of the file (ie.
153 * reads in sections and symbols, performs symbol resolution if more that one
154 * object file have been specified, and assigns input sections to output
155 * sections).
156 */
157 Rt_map *
158 elf_obj_file(Lm_list *lml, Aliste lmco, Rt_map *clmp, const char *name,
159 mmapobj_result_t *hmpp, mmapobj_result_t *mpp, uint_t mnum)
160 {
161 Rej_desc rej;
162 Mmap_desc md;
163
164 /*
165 * If this is the first relocatable object (LD_PRELOAD could provide a
166 * list of objects), initialize an input file descriptor and a link map.
167 */
168 if ((olmp == NULL) && ((olmp = elf_obj_init(lml, lmco, name)) == NULL))
169 return (NULL);
170
171 DBG_CALL(Dbg_util_nl(lml, DBG_NL_STD));
172
173 /*
174 * Keep track of the input image, as this must be free'd after all ELF
175 * processing is completed.
176 */
177 md.md_mpp = mpp;
178 md.md_mnum = mnum;
179 if (alist_append(&mpalp, &md, sizeof (Mmap_desc),
180 AL_CNT_MPOBJS) == NULL) {
181 remove_so(lml, olmp, clmp);
182 return (NULL);
183 }
184
185 /*
186 * Pass the object mapping to the link-editor to commence processing the
187 * file.
188 */
189 if (ld_process_mem(name, name, hmpp->mr_addr, hmpp->mr_msize,
190 (Ofl_desc *)ELFPRV(olmp), &rej) == (Ifl_desc *)S_ERROR) {
191 remove_so(lml, olmp, clmp);
192 return (NULL);
193 }
194
195 return (olmp);
196 }
197
198 /*
199 * Ensure any platform or machine capability names are valid.
200 */
201 inline static int
202 check_plat_names(Syscapset *scapset, Alist *caps, Rej_desc *rej)
203 {
204 Capstr *capstr;
205 Aliste idx;
206
207 for (ALIST_TRAVERSE(caps, idx, capstr)) {
208 if (platcap_check(scapset, capstr->cs_str, rej) == 1)
209 return (1);
210 }
211 return (0);
212 }
213
214 inline static int
215 check_mach_names(Syscapset *scapset, Alist *caps, Rej_desc *rej)
216 {
217 Capstr *capstr;
218 Aliste idx;
219
220 for (ALIST_TRAVERSE(caps, idx, capstr)) {
221 if (machcap_check(scapset, capstr->cs_str, rej) == 1)
222 return (1);
223 }
224 return (0);
225 }
226
227 /*
228 * Finish relocatable object processing. Having already initially processed one
229 * or more objects, complete the generation of a shared object image by calling
230 * the appropriate link-edit functionality (refer to sgs/ld/common/main.c).
231 */
232 Rt_map *
233 elf_obj_fini(Lm_list *lml, Rt_map *lmp, Rt_map *clmp, int *in_nfavl)
234 {
235 Ofl_desc *ofl = (Ofl_desc *)ELFPRV(lmp);
236 Rt_map *nlmp, *tlmp;
237 Ehdr *ehdr;
238 Phdr *phdr;
239 mmapobj_result_t *mpp, *hmpp;
240 uint_t phnum;
241 int mnum;
242 Lm_cntl *lmc;
243 Aliste idx1;
244 Mmap_desc *mdp;
245 Fdesc fd = { 0 };
246 Grp_hdl *ghp;
247 Rej_desc rej = { 0 };
248 Syscapset *scapset;
249 elfcap_mask_t omsk;
250 Alist *oalp;
251
252 DBG_CALL(Dbg_util_nl(lml, DBG_NL_STD));
253
254 if (ld_reloc_init(ofl) == S_ERROR)
255 return (NULL);
256 if (ld_sym_validate(ofl) == S_ERROR)
257 return (NULL);
258
259 /*
260 * At this point, all input section processing is complete. If any
261 * capabilities have been established, ensure that they are appropriate
262 * for this system.
263 */
264 if (pnavl_recorded(&capavl, ofl->ofl_name, NULL, NULL))
265 scapset = alt_scapset;
266 else
267 scapset = org_scapset;
268
269 if ((((omsk = ofl->ofl_ocapset.oc_hw_1.cm_val) != 0) &&
270 (hwcap1_check(scapset, omsk, &rej) == 0)) ||
271 (((omsk = ofl->ofl_ocapset.oc_sf_1.cm_val) != 0) &&
272 (sfcap1_check(scapset, omsk, &rej) == 0)) ||
273 (((omsk = ofl->ofl_ocapset.oc_hw_2.cm_val) != 0) &&
274 (hwcap2_check(scapset, omsk, &rej) == 0)) ||
275 (((oalp = ofl->ofl_ocapset.oc_plat.cl_val) != NULL) &&
276 (check_plat_names(scapset, oalp, &rej) == 0)) ||
277 (((oalp = ofl->ofl_ocapset.oc_mach.cl_val) != NULL) &&
278 (check_mach_names(scapset, oalp, &rej) == 0))) {
279 if ((lml_main.lm_flags & LML_FLG_TRC_LDDSTUB) && lmp &&
280 (FLAGS1(lmp) & FL1_RT_LDDSTUB) && (NEXT(lmp) == NULL)) {
281 /* LINTED */
282 (void) printf(MSG_INTL(ldd_reject[rej.rej_type]),
283 ofl->ofl_name, rej.rej_str);
284 }
285 return (NULL);
286 }
287
288 /*
289 * Finish creating the output file.
290 */
291 if (ld_make_sections(ofl) == S_ERROR)
292 return (NULL);
293 if (ld_create_outfile(ofl) == S_ERROR)
294 return (NULL);
295 if (ld_update_outfile(ofl) == S_ERROR)
296 return (NULL);
297 if (ld_reloc_process(ofl) == S_ERROR)
298 return (NULL);
299
300 /*
301 * At this point we have a memory image of the shared object. The link
302 * editor would normally simply write this to the required output file.
303 * If we're debugging generate a standard temporary output file.
304 */
305 DBG_CALL(Dbg_file_output(ofl));
306
307 /*
308 * Allocate a mapping array to retain mapped segment information.
309 */
310 ehdr = ofl->ofl_nehdr;
311 phdr = ofl->ofl_phdr;
312
313 if ((mpp = hmpp = calloc(ehdr->e_phnum,
314 sizeof (mmapobj_result_t))) == NULL)
315 return (NULL);
316 for (mnum = 0, phnum = 0; phnum < ehdr->e_phnum; phnum++) {
317 if (phdr[phnum].p_type != PT_LOAD)
318 continue;
319
320 mpp[mnum].mr_addr = (caddr_t)((uintptr_t)phdr[phnum].p_vaddr +
321 (uintptr_t)ehdr);
322 mpp[mnum].mr_msize = phdr[phnum].p_memsz;
323 mpp[mnum].mr_fsize = phdr[phnum].p_filesz;
324 mpp[mnum].mr_prot = (PROT_READ | PROT_WRITE | PROT_EXEC);
325 mnum++;
326 }
327
328 /*
329 * Generate a new link map representing the memory image created.
330 */
331 fd.fd_nname = ofl->ofl_name;
332 if ((nlmp = elf_new_lmp(lml, CNTL(olmp), &fd, (Addr)hmpp->mr_addr,
333 ofl->ofl_size, NULL, clmp, in_nfavl)) == NULL)
334 return (NULL);
335
336 MMAPS(nlmp) = hmpp;
337 MMAPCNT(nlmp) = mnum;
338 PADSTART(nlmp) = (ulong_t)hmpp->mr_addr;
339 PADIMLEN(nlmp) = mpp->mr_addr + mpp->mr_msize - hmpp->mr_addr;
340
341 /*
342 * Replace the original (temporary) link map with the new link map.
343 */
344 /* LINTED */
345 lmc = (Lm_cntl *)alist_item_by_offset(lml->lm_lists, CNTL(nlmp));
346 lml->lm_obj--;
347
348 if ((tlmp = PREV_RT_MAP(nlmp)) == olmp)
349 tlmp = nlmp;
350
351 if (PREV(olmp)) {
352 NEXT(PREV_RT_MAP(olmp)) = (Link_map *)nlmp;
353 PREV(nlmp) = PREV(olmp);
354 } else {
355 PREV(nlmp) = NULL;
356 lmc->lc_head = nlmp;
357 if (CNTL(nlmp) == ALIST_OFF_DATA)
358 lml->lm_head = nlmp;
359 }
360
361 if (NEXT(olmp) != (Link_map *)nlmp) {
362 NEXT(nlmp) = NEXT(olmp);
363 PREV(NEXT_RT_MAP(olmp)) = (Link_map *)nlmp;
364 }
365
366 NEXT(tlmp) = NULL;
367
368 lmc->lc_tail = tlmp;
369 if (CNTL(nlmp) == ALIST_OFF_DATA)
370 lml->lm_tail = tlmp;
371
372 HANDLES(nlmp) = HANDLES(olmp);
373 GROUPS(nlmp) = GROUPS(olmp);
374 STDEV(nlmp) = STDEV(olmp);
375 STINO(nlmp) = STINO(olmp);
376
377 FLAGS(nlmp) |= ((FLAGS(olmp) & ~FLG_RT_OBJECT) | FLG_RT_IMGALLOC);
378 FLAGS1(nlmp) |= FLAGS1(olmp);
379 MODE(nlmp) |= MODE(olmp);
380
381 NAME(nlmp) = NAME(olmp);
382
383 /*
384 * Reassign any original handles to the new link-map.
385 */
386 for (APLIST_TRAVERSE(HANDLES(nlmp), idx1, ghp)) {
387 Grp_desc *gdp;
388 Aliste idx2;
389
390 ghp->gh_ownlmp = nlmp;
391
392 for (ALIST_TRAVERSE(ghp->gh_depends, idx2, gdp)) {
393 if (gdp->gd_depend == olmp) {
394 gdp->gd_depend = nlmp;
395 break;
396 }
397 }
398 }
399
400 ld_ofl_cleanup(ofl);
401 free(ELFPRV(olmp));
402 free(olmp);
403 olmp = 0;
404
405 /*
406 * Unmap the original relocatable object.
407 */
408 for (ALIST_TRAVERSE(mpalp, idx1, mdp)) {
409 unmap_obj(mdp->md_mpp, mdp->md_mnum);
410 free(mdp->md_mpp);
411 }
412 free(mpalp);
413 mpalp = NULL;
414
415 /*
416 * Now that we've allocated our permanent link map structure, expand the
417 * PATHNAME() and insert this path name into the FullPathNode AVL tree.
418 */
419 (void) fullpath(nlmp, 0);
420 if (fpavl_insert(lml, nlmp, PATHNAME(nlmp), 0) == 0)
421 return (NULL);
422
423 /*
424 * If we're being audited tell the audit library of the file we've just
425 * opened.
426 */
427 if ((lml->lm_tflags | AFLAGS(nlmp)) & LML_TFLG_AUD_MASK) {
428 if (audit_objopen(nlmp, nlmp) == 0)
429 return (NULL);
430 }
431 return (nlmp);
432 }