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sourceware.org Git - glibc.git/blob - elf/dl-version.c
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 /* Display information about what we are doing while debugging. */
83 if (_dl_debug_versions
)
84 _dl_debug_message (1, "checking for version `", string
, "' in file ",
85 map
->l_name
[0] ? map
->l_name
: _dl_argv
[0],
86 " required by file ", name
, "\n", NULL
);
88 if (map
->l_info
[VERSTAG (DT_VERDEF
)] == NULL
)
90 /* The file has no symbol versioning. I.e., the dependent
91 object was linked against another version of this file. We
92 only print a message if verbose output is requested. */
94 _dl_signal_error (0, map
->l_name
, make_string ("\
95 no version information available (required by ",
100 def_offset
= map
->l_info
[VERSTAG (DT_VERDEF
)]->d_un
.d_ptr
;
101 assert (def_offset
!= 0);
103 def
= (ElfW(Verdef
) *) ((char *) map
->l_addr
+ def_offset
);
106 /* Currently the version number of the definition entry is 1.
107 Make sure all we see is this version. */
108 if (def
->vd_version
!= 1)
111 buf
[sizeof (buf
) - 1] = '\0';
112 _dl_signal_error (0, map
->l_name
,
113 make_string ("unsupported version ",
114 _itoa_word (def
->vd_version
,
115 &buf
[sizeof (buf
) - 1],
117 " of Verdef record"));
121 /* Compare the hash values. */
122 if (hash
== def
->vd_hash
)
124 ElfW(Verdaux
) *aux
= (ElfW(Verdaux
) *) ((char *) def
+ def
->vd_aux
);
126 /* To be safe, compare the string as well. */
127 if (strcmp (string
, strtab
+ aux
->vda_name
) == 0)
132 /* If no more definitions we failed to find what we want. */
133 if (def
->vd_next
== 0)
136 /* Next definition. */
137 def
= (ElfW(Verdef
) *) ((char *) def
+ def
->vd_next
);
140 /* Symbol not found. If it was a weak reference it is not fatal. */
144 _dl_signal_error (0, map
->l_name
,
145 make_string ("weak version `", string
,
146 "' not found (required by ", name
,
151 _dl_signal_error (0, map
->l_name
,
152 make_string ("version `", string
,
153 "' not found (required by ", name
, ")"));
159 _dl_check_map_versions (struct link_map
*map
, int verbose
)
163 /* Pointer to section with needed versions. */
165 /* Pointer to dynamic section with definitions. */
167 /* We need to find out which is the highest version index used
169 unsigned int ndx_high
= 0;
171 /* If we don't have a string table, we must be ok. */
172 if (map
->l_info
[DT_STRTAB
] == NULL
)
174 strtab
= (const char *) (map
->l_addr
+ map
->l_info
[DT_STRTAB
]->d_un
.d_ptr
);
176 dyn
= map
->l_info
[VERSTAG (DT_VERNEED
)];
177 def
= map
->l_info
[VERSTAG (DT_VERDEF
)];
181 /* This file requires special versions from its dependencies. */
182 ElfW(Verneed
) *ent
= (ElfW(Verneed
) *) (map
->l_addr
+ dyn
->d_un
.d_ptr
);
184 /* Currently the version number of the needed entry is 1.
185 Make sure all we see is this version. */
186 if (ent
->vn_version
!= 1)
189 buf
[sizeof (buf
) - 1] = '\0';
190 _dl_signal_error (0, (*map
->l_name
? map
->l_name
: _dl_argv
[0]),
191 make_string ("unsupported version ",
192 _itoa_word (ent
->vn_version
,
193 &buf
[sizeof (buf
) - 1],
195 " of Verneed record\n"));
202 struct link_map
*needed
= find_needed (strtab
+ ent
->vn_file
, map
);
204 /* If NEEDED is NULL this means a dependency was not found
205 and no stub entry was created. This should never happen. */
206 assert (needed
!= NULL
);
208 /* NEEDED is the map for the file we need. Now look for the
209 dependency symbols. */
210 aux
= (ElfW(Vernaux
) *) ((char *) ent
+ ent
->vn_aux
);
213 /* Match the symbol. */
214 result
|= match_symbol ((*map
->l_name
215 ? map
->l_name
: _dl_argv
[0]),
217 strtab
+ aux
->vna_name
,
219 aux
->vna_flags
& VER_FLG_WEAK
);
221 /* Compare the version index. */
222 if ((unsigned int) (aux
->vna_other
& 0x7fff) > ndx_high
)
223 ndx_high
= aux
->vna_other
& 0x7fff;
225 if (aux
->vna_next
== 0)
226 /* No more symbols. */
230 aux
= (ElfW(Vernaux
) *) ((char *) aux
+ aux
->vna_next
);
233 if (ent
->vn_next
== 0)
234 /* No more dependencies. */
237 /* Next dependency. */
238 ent
= (ElfW(Verneed
) *) ((char *) ent
+ ent
->vn_next
);
242 /* We also must store the names of the defined versions. Determine
243 the maximum index here as well.
245 XXX We could avoid the loop by just taking the number of definitions
246 as an upper bound of new indeces. */
250 ent
= (ElfW(Verdef
) *) (map
->l_addr
+ def
->d_un
.d_ptr
);
253 if ((unsigned int) (ent
->vd_ndx
& 0x7fff) > ndx_high
)
254 ndx_high
= ent
->vd_ndx
& 0x7fff;
256 if (ent
->vd_next
== 0)
257 /* No more definitions. */
260 ent
= (ElfW(Verdef
) *) ((char *) ent
+ ent
->vd_next
);
266 /* Now we are ready to build the array with the version names
267 which can be indexed by the version index in the VERSYM
269 map
->l_versions
= (struct r_found_version
*)
270 calloc (ndx_high
+ 1, sizeof (*map
->l_versions
));
271 if (map
->l_versions
== NULL
)
273 _dl_signal_error (ENOMEM
, (*map
->l_name
? map
->l_name
: _dl_argv
[0]),
274 "cannot allocate version reference table");
279 /* Store the number of available symbols. */
280 map
->l_nversions
= ndx_high
+ 1;
282 /* Compute the pointer to the version symbols. */
283 map
->l_versyms
= ((void *) map
->l_addr
284 + map
->l_info
[VERSTAG (DT_VERSYM
)]->d_un
.d_ptr
);
289 ent
= (ElfW(Verneed
) *) (map
->l_addr
+ dyn
->d_un
.d_ptr
);
293 aux
= (ElfW(Vernaux
) *) ((char *) ent
+ ent
->vn_aux
);
296 ElfW(Half
) ndx
= aux
->vna_other
& 0x7fff;
297 map
->l_versions
[ndx
].hash
= aux
->vna_hash
;
298 map
->l_versions
[ndx
].hidden
= aux
->vna_other
& 0x8000;
299 map
->l_versions
[ndx
].name
= &strtab
[aux
->vna_name
];
300 map
->l_versions
[ndx
].filename
= &strtab
[ent
->vn_file
];
302 if (aux
->vna_next
== 0)
303 /* No more symbols. */
306 /* Advance to next symbol. */
307 aux
= (ElfW(Vernaux
) *) ((char *) aux
+ aux
->vna_next
);
310 if (ent
->vn_next
== 0)
311 /* No more dependencies. */
314 /* Advance to next dependency. */
315 ent
= (ElfW(Verneed
) *) ((char *) ent
+ ent
->vn_next
);
319 /* And insert the defined versions. */
323 ent
= (ElfW(Verdef
) *) (map
->l_addr
+ def
->d_un
.d_ptr
);
327 aux
= (ElfW(Verdaux
) *) ((char *) ent
+ ent
->vd_aux
);
329 if ((ent
->vd_flags
& VER_FLG_BASE
) == 0)
331 /* The name of the base version should not be
332 available for matching a versioned symbol. */
333 ElfW(Half
) ndx
= ent
->vd_ndx
& 0x7fff;
334 map
->l_versions
[ndx
].hash
= ent
->vd_hash
;
335 map
->l_versions
[ndx
].name
= &strtab
[aux
->vda_name
];
336 map
->l_versions
[ndx
].filename
= NULL
;
339 if (ent
->vd_next
== 0)
340 /* No more definitions. */
343 ent
= (ElfW(Verdef
) *) ((char *) ent
+ ent
->vd_next
);
354 _dl_check_all_versions (struct link_map
*map
, int verbose
)
359 for (l
= map
; l
!= NULL
; l
= l
->l_next
)
360 result
|= l
->l_opencount
!= 0 && _dl_check_map_versions (l
, verbose
);
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