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