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) 1994, 2010, Oracle and/or its affiliates. All rights reserved.
24 */
25
26 #include <stdio.h>
27 #include <dlfcn.h>
28 #include <libelf.h>
29 #include <link.h>
30 #include <debug.h>
31 #include "msg.h"
32 #include "_libld.h"
33
34 /*
35 * Table which defines the default functions to be called by the library
36 * SUPPORT (-S <libname>). These functions can be redefined by the
37 * ld_support_loadso() routine.
38 */
39 static Support_list support[LDS_NUM] = {
40 {MSG_ORIG(MSG_SUP_VERSION), NULL}, /* LDS_VERSION */
41 {MSG_ORIG(MSG_SUP_INPUT_DONE), NULL}, /* LDS_INPUT_DONE */
42 #if defined(_ELF64)
43 {MSG_ORIG(MSG_SUP_START_64), NULL}, /* LDS_START */
44 {MSG_ORIG(MSG_SUP_ATEXIT_64), NULL}, /* LDS_ATEXIT */
45 {MSG_ORIG(MSG_SUP_OPEN_64), NULL}, /* LDS_OPEN */
46 {MSG_ORIG(MSG_SUP_FILE_64), NULL}, /* LDS_FILE */
47 {MSG_ORIG(MSG_SUP_INSEC_64), NULL}, /* LDS_INSEC */
48 {MSG_ORIG(MSG_SUP_SEC_64), NULL} /* LDS_SEC */
49 #else /* Elf32 */
50 {MSG_ORIG(MSG_SUP_START), NULL}, /* LDS_START */
51 {MSG_ORIG(MSG_SUP_ATEXIT), NULL}, /* LDS_ATEXIT */
52 {MSG_ORIG(MSG_SUP_OPEN), NULL}, /* LDS_OPEN */
53 {MSG_ORIG(MSG_SUP_FILE), NULL}, /* LDS_FILE */
54 {MSG_ORIG(MSG_SUP_INSEC), NULL}, /* LDS_INSEC */
55 {MSG_ORIG(MSG_SUP_SEC), NULL} /* LDS_SEC */
56 #endif
57 };
58
59 /*
60 * Loads in a support shared object specified using the SGS_SUPPORT environment
61 * variable or the -S ld option, and determines which interface functions are
62 * provided by that object.
63 */
64 uintptr_t
ld_sup_loadso(Ofl_desc * ofl,const char * obj)65 ld_sup_loadso(Ofl_desc *ofl, const char *obj)
66 {
67 void *handle, *fptr;
68 uint_t interface, version = LD_SUP_VERSION1;
69
70 /*
71 * Load the required support library. If we are unable to load it fail
72 * with a fatal error.
73 */
74 if ((handle = dlopen(obj, (RTLD_LAZY | RTLD_FIRST))) == NULL) {
75 ld_eprintf(ofl, ERR_FATAL, MSG_INTL(MSG_SUP_NOLOAD),
76 obj, dlerror());
77 return (S_ERROR);
78 }
79
80 for (interface = 0; interface < LDS_NUM; interface++) {
81 Func_list fl;
82
83 if ((fptr = dlsym(handle, support[interface].sup_name)) == NULL)
84 continue;
85
86 DBG_CALL(Dbg_support_load(ofl->ofl_lml, obj,
87 support[interface].sup_name));
88
89 if (interface == LDS_VERSION) {
90 DBG_CALL(Dbg_support_action(ofl->ofl_lml, obj,
91 support[LDS_VERSION].sup_name, LDS_VERSION, 0));
92
93 version = ((uint_t(*)())fptr)(LD_SUP_VCURRENT);
94
95 /*
96 * If version is LD_SUP_VNONE, unload the support
97 * library and act as if it was never requested.
98 * This provides the support library with a mechanism
99 * for opting out of the process.
100 *
101 * Note that this depends on LDS_VERSION being the
102 * first item in support[]. If this were not true,
103 * then other functions from the library might be
104 * entered into the function lists, and unloading
105 * the object would cause corruption.
106 */
107 assert(LDS_VERSION == 0);
108 if (version == LD_SUP_VNONE) {
109 DBG_CALL(Dbg_support_vnone(ofl->ofl_lml,
110 obj));
111 (void) dlclose(handle);
112 return (1);
113 }
114
115 /*
116 * If the support library has a version higher
117 * than we support, we are unable to accept it.
118 */
119 if (version > LD_SUP_VCURRENT) {
120 ld_eprintf(ofl, ERR_FATAL,
121 MSG_INTL(MSG_SUP_BADVERSION), obj,
122 LD_SUP_VCURRENT, version);
123 (void) dlclose(handle);
124 return (S_ERROR);
125 }
126 }
127
128 fl.fl_obj = obj;
129 fl.fl_fptr = fptr;
130 fl.fl_version = version;
131 if (alist_append(&support[interface].sup_funcs, &fl,
132 sizeof (Func_list), AL_CNT_SUPPORT) == NULL)
133 return (S_ERROR);
134 }
135 return (1);
136 }
137
138 /*
139 * Wrapper routines for the ld support library calls.
140 */
141 void
ld_sup_start(Ofl_desc * ofl,const Half etype,const char * caller)142 ld_sup_start(Ofl_desc *ofl, const Half etype, const char *caller)
143 {
144 Func_list *flp;
145 Aliste idx;
146
147 for (ALIST_TRAVERSE(support[LDS_START].sup_funcs, idx, flp)) {
148 DBG_CALL(Dbg_support_action(ofl->ofl_lml, flp->fl_obj,
149 support[LDS_START].sup_name, LDS_START, ofl->ofl_name));
150 (*flp->fl_fptr)(ofl->ofl_name, etype, caller);
151 }
152 }
153
154 void
ld_sup_atexit(Ofl_desc * ofl,int ecode)155 ld_sup_atexit(Ofl_desc *ofl, int ecode)
156 {
157 Func_list *flp;
158 Aliste idx;
159
160 for (ALIST_TRAVERSE(support[LDS_ATEXIT].sup_funcs, idx, flp)) {
161 DBG_CALL(Dbg_support_action(ofl->ofl_lml, flp->fl_obj,
162 support[LDS_ATEXIT].sup_name, LDS_ATEXIT, 0));
163 (*flp->fl_fptr)(ecode);
164 }
165 }
166
167 void
ld_sup_open(Ofl_desc * ofl,const char ** opath,const char ** ofile,int * ofd,int flags,Elf ** oelf,Elf * ref,size_t off,const Elf_Kind ekind)168 ld_sup_open(Ofl_desc *ofl, const char **opath, const char **ofile, int *ofd,
169 int flags, Elf **oelf, Elf *ref, size_t off, const Elf_Kind ekind)
170 {
171 Func_list *flp;
172 Aliste idx;
173
174 for (ALIST_TRAVERSE(support[LDS_OPEN].sup_funcs, idx, flp)) {
175 const char *npath = *opath;
176 const char *nfile = *ofile;
177 Elf *nelf = *oelf;
178 int nfd = *ofd;
179 int _flags = 0;
180
181 /*
182 * This interface was introduced in VERSION3. Only call this
183 * function for libraries reporting support for version 3 or
184 * above.
185 */
186 if (flp->fl_version < LD_SUP_VERSION3)
187 continue;
188
189 if (!(flags & FLG_IF_CMDLINE))
190 _flags |= LD_SUP_DERIVED;
191 if (!(flags & FLG_IF_NEEDED))
192 _flags |= LD_SUP_INHERITED;
193 if (flags & FLG_IF_EXTRACT)
194 _flags |= LD_SUP_EXTRACTED;
195
196 /*
197 * If the present object is an extracted archive member, make
198 * sure the archive offset is reset so that the caller can
199 * obtain an ELF descriptor to the same member (an elf_begin()
200 * moves the offset to the next member).
201 */
202 if (flags & FLG_IF_EXTRACT)
203 (void) elf_rand(ref, off);
204
205 DBG_CALL(Dbg_support_action(ofl->ofl_lml, flp->fl_obj,
206 support[LDS_OPEN].sup_name, LDS_OPEN, *opath));
207 (*flp->fl_fptr)(&npath, &nfile, &nfd, _flags, &nelf, ref, off,
208 ekind);
209
210 /*
211 * If the file descriptor, ELF descriptor, or file names have
212 * been modified, then diagnose the differences and return the
213 * new data. As a basic test, make sure the support library
214 * hasn't nulled out data ld(1) will try and dereference.
215 */
216 if ((npath != *opath) || (nfd != *ofd) || (nelf != *oelf)) {
217 DBG_CALL(Dbg_file_modified(ofl->ofl_lml, flp->fl_obj,
218 *opath, npath, *ofd, nfd, *oelf, nelf));
219 if (npath)
220 *opath = npath;
221 if (nfile)
222 *ofile = nfile;
223 *ofd = nfd;
224 *oelf = nelf;
225 }
226 }
227 }
228
229 void
ld_sup_file(Ofl_desc * ofl,const char * ifile,const Elf_Kind ekind,int flags,Elf * elf)230 ld_sup_file(Ofl_desc *ofl, const char *ifile, const Elf_Kind ekind, int flags,
231 Elf *elf)
232 {
233 Func_list *flp;
234 Aliste idx;
235
236 for (ALIST_TRAVERSE(support[LDS_FILE].sup_funcs, idx, flp)) {
237 int _flags = 0;
238
239 if (!(flags & FLG_IF_CMDLINE))
240 _flags |= LD_SUP_DERIVED;
241 if (!(flags & FLG_IF_NEEDED))
242 _flags |= LD_SUP_INHERITED;
243 if (flags & FLG_IF_EXTRACT)
244 _flags |= LD_SUP_EXTRACTED;
245
246 DBG_CALL(Dbg_support_action(ofl->ofl_lml, flp->fl_obj,
247 support[LDS_FILE].sup_name, LDS_FILE, ifile));
248 (*flp->fl_fptr)(ifile, ekind, _flags, elf);
249 }
250 }
251
252 uintptr_t
ld_sup_input_section(Ofl_desc * ofl,Ifl_desc * ifl,const char * sname,Shdr ** oshdr,Word ndx,Elf_Scn * scn,Elf * elf)253 ld_sup_input_section(Ofl_desc *ofl, Ifl_desc *ifl, const char *sname,
254 Shdr **oshdr, Word ndx, Elf_Scn *scn, Elf *elf)
255 {
256 Func_list *flp;
257 Aliste idx;
258 uint_t flags = 0;
259 Elf_Data *data = NULL;
260
261 for (ALIST_TRAVERSE(support[LDS_INSEC].sup_funcs, idx, flp)) {
262 Shdr *nshdr = *oshdr;
263
264 /*
265 * This interface was introduced in VERSION2. Only call this
266 * function for libraries reporting support for version 2 or
267 * above.
268 */
269 if (flp->fl_version < LD_SUP_VERSION2)
270 continue;
271
272 if ((data == NULL) &&
273 ((data = elf_getdata(scn, NULL)) == NULL)) {
274 ld_eprintf(ofl, ERR_ELF, MSG_INTL(MSG_ELF_GETDATA),
275 ifl->ifl_name);
276 return (S_ERROR);
277 }
278
279 DBG_CALL(Dbg_support_action(ofl->ofl_lml, flp->fl_obj,
280 support[LDS_INSEC].sup_name, LDS_INSEC, sname));
281 (*flp->fl_fptr)(sname, &nshdr, ndx, data, elf, &flags);
282
283 /*
284 * If the section header has been re-allocated (known to occur
285 * with libCCexcept.so), then diagnose the section header
286 * difference and return the new section header.
287 */
288 if (nshdr != *oshdr) {
289 Ehdr *ehdr = ifl->ifl_ehdr;
290
291 DBG_CALL(Dbg_shdr_modified(ofl->ofl_lml, flp->fl_obj,
292 ehdr->e_ident[EI_OSABI], ehdr->e_machine, ndx,
293 *oshdr, nshdr, sname));
294 *oshdr = nshdr;
295 }
296 }
297 return (0);
298 }
299
300 void
ld_sup_section(Ofl_desc * ofl,const char * scn,Shdr * shdr,Word ndx,Elf_Data * data,Elf * elf)301 ld_sup_section(Ofl_desc *ofl, const char *scn, Shdr *shdr, Word ndx,
302 Elf_Data *data, Elf *elf)
303 {
304 Func_list *flp;
305 Aliste idx;
306
307 for (ALIST_TRAVERSE(support[LDS_SEC].sup_funcs, idx, flp)) {
308 DBG_CALL(Dbg_support_action(ofl->ofl_lml, flp->fl_obj,
309 support[LDS_SEC].sup_name, LDS_SEC, scn));
310 (*flp->fl_fptr)(scn, shdr, ndx, data, elf);
311 }
312 }
313
314 void
ld_sup_input_done(Ofl_desc * ofl)315 ld_sup_input_done(Ofl_desc *ofl)
316 {
317 Func_list *flp;
318 Aliste idx;
319 uint_t flags = 0;
320
321 for (ALIST_TRAVERSE(support[LDS_INPUT_DONE].sup_funcs, idx, flp)) {
322 /*
323 * This interface was introduced in VERSION2. Only call this
324 * function for libraries reporting support for version 2 or
325 * above.
326 */
327 if (flp->fl_version < LD_SUP_VERSION2)
328 continue;
329
330 DBG_CALL(Dbg_support_action(ofl->ofl_lml, flp->fl_obj,
331 support[LDS_INPUT_DONE].sup_name, LDS_INPUT_DONE, 0));
332 (*flp->fl_fptr)(&flags);
333 }
334 }
335