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sourceware.org Git - glibc.git/blob - elf/dl-version.c
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1 /* Handle symbol and library versioning.
2 Copyright (C) 1997, 1998 Free Software Foundation, Inc.
3 This file is part of the GNU C Library.
4 Contributed by Ulrich Drepper <drepper@cygnus.com>, 1997.
6 The GNU C Library is free software; you can redistribute it and/or
7 modify it under the terms of the GNU Library General Public License as
8 published by the Free Software Foundation; either version 2 of the
9 License, or (at your option) any later version.
11 The GNU C Library is distributed in the hope that it will be useful,
12 but WITHOUT ANY WARRANTY; without even the implied warranty of
13 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
14 Library General Public License for more details.
16 You should have received a copy of the GNU Library General Public
17 License along with the GNU C Library; see the file COPYING.LIB. If not,
18 write to the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
19 Boston, MA 02111-1307, USA. */
28 #include <stdio-common/_itoa.h>
31 #define VERSTAG(tag) (DT_NUM + DT_PROCNUM + DT_VERSIONTAGIDX (tag))
34 #define make_string(string, rest...) \
36 const char *all[] = { string, ## rest }; \
41 for (cnt = 0; cnt < sizeof (all) / sizeof (all[0]); ++cnt) \
42 len += strlen (all[cnt]); \
44 cp = result = alloca (len); \
45 for (cnt = 0; cnt < sizeof (all) / sizeof (all[0]); ++cnt) \
46 cp = __stpcpy (cp, all[cnt]); \
52 static inline struct link_map
*
53 find_needed (const char *name
, struct link_map
*map
)
55 struct link_map
*tmap
;
58 for (tmap
= _dl_loaded
; tmap
!= NULL
; tmap
= tmap
->l_next
)
59 if (_dl_name_match_p (name
, tmap
))
62 /* The required object is not in the global scope, look to see if it is
63 a dependency of the current object. */
64 for (n
= 0; n
< map
->l_nsearchlist
; n
++)
65 if (_dl_name_match_p (name
, map
->l_searchlist
[n
]))
66 return map
->l_searchlist
[n
];
68 /* Should never happen. */
74 match_symbol (const char *name
, ElfW(Word
) hash
, const char *string
,
75 struct link_map
*map
, int verbose
, int weak
)
77 const char *strtab
= (const char *) (map
->l_addr
78 + map
->l_info
[DT_STRTAB
]->d_un
.d_ptr
);
79 ElfW(Addr
) def_offset
;
82 if (map
->l_info
[VERSTAG (DT_VERDEF
)] == NULL
)
84 /* The file has no symbol versioning. I.e., the dependent
85 object was linked against another version of this file. We
86 only print a message if verbose output is requested. */
88 _dl_signal_error (0, map
->l_name
, make_string ("\
89 no version information available (required by ",
94 def_offset
= map
->l_info
[VERSTAG (DT_VERDEF
)]->d_un
.d_ptr
;
95 assert (def_offset
!= 0);
97 def
= (ElfW(Verdef
) *) ((char *) map
->l_addr
+ def_offset
);
100 /* Currently the version number of the definition entry is 1.
101 Make sure all we see is this version. */
102 if (def
->vd_version
!= 1)
105 buf
[sizeof (buf
) - 1] = '\0';
106 _dl_signal_error (0, map
->l_name
,
107 make_string ("unsupported version ",
108 _itoa_word (def
->vd_version
,
109 &buf
[sizeof (buf
) - 1],
111 " of Verdef record"));
115 /* Compare the hash values. */
116 if (hash
== def
->vd_hash
)
118 ElfW(Verdaux
) *aux
= (ElfW(Verdaux
) *) ((char *) def
+ def
->vd_aux
);
120 /* To be safe, compare the string as well. */
121 if (strcmp (string
, strtab
+ aux
->vda_name
) == 0)
126 /* If no more definitions we failed to find what we want. */
127 if (def
->vd_next
== 0)
130 /* Next definition. */
131 def
= (ElfW(Verdef
) *) ((char *) def
+ def
->vd_next
);
134 /* Symbol not found. If it was a weak reference it is not fatal. */
138 _dl_signal_error (0, map
->l_name
,
139 make_string ("weak version `", string
,
140 "' not found (required by ", name
,
145 _dl_signal_error (0, map
->l_name
,
146 make_string ("version `", string
,
147 "' not found (required by ", name
, ")"));
153 _dl_check_map_versions (struct link_map
*map
, int verbose
)
157 /* Pointer to section with needed versions. */
159 /* Pointer to dynamic section with definitions. */
161 /* We need to find out which is the highest version index used
163 unsigned int ndx_high
= 0;
165 /* If we don't have a string table, we must be ok. */
166 if (map
->l_info
[DT_STRTAB
] == NULL
)
168 strtab
= (const char *) (map
->l_addr
+ map
->l_info
[DT_STRTAB
]->d_un
.d_ptr
);
170 dyn
= map
->l_info
[VERSTAG (DT_VERNEED
)];
171 def
= map
->l_info
[VERSTAG (DT_VERDEF
)];
175 /* This file requires special versions from its dependencies. */
176 ElfW(Verneed
) *ent
= (ElfW(Verneed
) *) (map
->l_addr
+ dyn
->d_un
.d_ptr
);
178 /* Currently the version number of the needed entry is 1.
179 Make sure all we see is this version. */
180 if (ent
->vn_version
!= 1)
183 buf
[sizeof (buf
) - 1] = '\0';
184 _dl_signal_error (0, (*map
->l_name
? map
->l_name
: _dl_argv
[0]),
185 make_string ("unsupported version ",
186 _itoa_word (ent
->vn_version
,
187 &buf
[sizeof (buf
) - 1],
189 " of Verneed record\n"));
196 struct link_map
*needed
= find_needed (strtab
+ ent
->vn_file
, map
);
198 /* If NEEDED is NULL this means a dependency was not found
199 and no stub entry was created. This should never happen. */
200 assert (needed
!= NULL
);
202 /* NEEDED is the map for the file we need. Now look for the
203 dependency symbols. */
204 aux
= (ElfW(Vernaux
) *) ((char *) ent
+ ent
->vn_aux
);
207 /* Match the symbol. */
208 result
|= match_symbol ((*map
->l_name
209 ? map
->l_name
: _dl_argv
[0]),
211 strtab
+ aux
->vna_name
,
213 aux
->vna_flags
& VER_FLG_WEAK
);
215 /* Compare the version index. */
216 if ((unsigned int) (aux
->vna_other
& 0x7fff) > ndx_high
)
217 ndx_high
= aux
->vna_other
& 0x7fff;
219 if (aux
->vna_next
== 0)
220 /* No more symbols. */
224 aux
= (ElfW(Vernaux
) *) ((char *) aux
+ aux
->vna_next
);
227 if (ent
->vn_next
== 0)
228 /* No more dependencies. */
231 /* Next dependency. */
232 ent
= (ElfW(Verneed
) *) ((char *) ent
+ ent
->vn_next
);
236 /* We also must store the names of the defined versions. Determine
237 the maximum index here as well.
239 XXX We could avoid the loop by just taking the number of definitions
240 as an upper bound of new indeces. */
244 ent
= (ElfW(Verdef
) *) (map
->l_addr
+ def
->d_un
.d_ptr
);
247 if ((unsigned int) (ent
->vd_ndx
& 0x7fff) > ndx_high
)
248 ndx_high
= ent
->vd_ndx
& 0x7fff;
250 if (ent
->vd_next
== 0)
251 /* No more definitions. */
254 ent
= (ElfW(Verdef
) *) ((char *) ent
+ ent
->vd_next
);
260 /* Now we are ready to build the array with the version names
261 which can be indexed by the version index in the VERSYM
263 map
->l_versions
= (struct r_found_version
*)
264 calloc (ndx_high
+ 1, sizeof (*map
->l_versions
));
265 if (map
->l_versions
== NULL
)
267 _dl_signal_error (ENOMEM
, (*map
->l_name
? map
->l_name
: _dl_argv
[0]),
268 "cannot allocate version reference table");
273 /* Store the number of available symbols. */
274 map
->l_nversions
= ndx_high
+ 1;
276 /* Compute the pointer to the version symbols. */
277 map
->l_versyms
= ((void *) map
->l_addr
278 + map
->l_info
[VERSTAG (DT_VERSYM
)]->d_un
.d_ptr
);
283 ent
= (ElfW(Verneed
) *) (map
->l_addr
+ dyn
->d_un
.d_ptr
);
287 aux
= (ElfW(Vernaux
) *) ((char *) ent
+ ent
->vn_aux
);
290 ElfW(Half
) ndx
= aux
->vna_other
& 0x7fff;
291 map
->l_versions
[ndx
].hash
= aux
->vna_hash
;
292 map
->l_versions
[ndx
].hidden
= aux
->vna_other
& 0x8000;
293 map
->l_versions
[ndx
].name
= &strtab
[aux
->vna_name
];
294 map
->l_versions
[ndx
].filename
= &strtab
[ent
->vn_file
];
296 if (aux
->vna_next
== 0)
297 /* No more symbols. */
300 /* Advance to next symbol. */
301 aux
= (ElfW(Vernaux
) *) ((char *) aux
+ aux
->vna_next
);
304 if (ent
->vn_next
== 0)
305 /* No more dependencies. */
308 /* Advance to next dependency. */
309 ent
= (ElfW(Verneed
) *) ((char *) ent
+ ent
->vn_next
);
313 /* And insert the defined versions. */
317 ent
= (ElfW(Verdef
) *) (map
->l_addr
+ def
->d_un
.d_ptr
);
321 aux
= (ElfW(Verdaux
) *) ((char *) ent
+ ent
->vd_aux
);
323 if ((ent
->vd_flags
& VER_FLG_BASE
) == 0)
325 /* The name of the base version should not be
326 available for matching a versioned symbol. */
327 ElfW(Half
) ndx
= ent
->vd_ndx
& 0x7fff;
328 map
->l_versions
[ndx
].hash
= ent
->vd_hash
;
329 map
->l_versions
[ndx
].name
= &strtab
[aux
->vda_name
];
330 map
->l_versions
[ndx
].filename
= NULL
;
333 if (ent
->vd_next
== 0)
334 /* No more definitions. */
337 ent
= (ElfW(Verdef
) *) ((char *) ent
+ ent
->vd_next
);
348 _dl_check_all_versions (struct link_map
*map
, int verbose
)
353 for (l
= map
; l
!= NULL
; l
= l
->l_next
)
354 result
|= l
->l_opencount
!= 0 && _dl_check_map_versions (l
, verbose
);
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