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sourceware.org Git - glibc.git/blob - elf/dl-close.c
094db533ddfd9735dea40d3144bcb4ea765f7e88
1 /* Close a shared object opened by `_dl_open'.
2 Copyright (C) 1996-2001, 2002 Free Software Foundation, Inc.
3 This file is part of the GNU C Library.
5 The GNU C Library is free software; you can redistribute it and/or
6 modify it under the terms of the GNU Lesser General Public
7 License as published by the Free Software Foundation; either
8 version 2.1 of the License, or (at your option) any later version.
10 The GNU C Library is distributed in the hope that it will be useful,
11 but WITHOUT ANY WARRANTY; without even the implied warranty of
12 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
13 Lesser General Public License for more details.
15 You should have received a copy of the GNU Lesser General Public
16 License along with the GNU C Library; if not, write to the Free
17 Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
26 #include <bits/libc-lock.h>
28 #include <sys/types.h>
32 /* Type of the constructor functions. */
33 typedef void (*fini_t
) (void);
37 /* Returns true we an non-empty was found. */
39 remove_slotinfo (size_t idx
, struct dtv_slotinfo_list
*listp
, size_t disp
,
42 if (idx
- disp
>= listp
->len
)
44 if (listp
->next
== NULL
)
46 /* The index is not actually valid in the slotinfo list,
47 because this object was closed before it was fully set
48 up due to some error. */
49 assert (! should_be_there
);
53 if (remove_slotinfo (idx
, listp
->next
, disp
+ listp
->len
,
57 /* No non-empty entry. Search from the end of this element's
59 idx
= disp
+ listp
->len
;
64 struct link_map
*old_map
= listp
->slotinfo
[idx
- disp
].map
;
66 /* The entry might still be in its unused state if we are closing an
67 object that wasn't fully set up. */
68 if (__builtin_expect (old_map
!= NULL
, 1))
70 assert (old_map
->l_tls_modid
== idx
);
72 /* Mark the entry as unused. */
73 listp
->slotinfo
[idx
- disp
].gen
= GL(dl_tls_generation
) + 1;
74 listp
->slotinfo
[idx
- disp
].map
= NULL
;
77 /* If this is not the last currently used entry no need to look
79 if (idx
!= GL(dl_tls_max_dtv_idx
))
83 while (idx
- disp
> disp
== 0 ? 1 + GL(dl_tls_static_nelem
) : 0)
87 if (listp
->slotinfo
[idx
- disp
].map
!= NULL
)
89 /* Found a new last used index. */
90 GL(dl_tls_max_dtv_idx
) = idx
;
95 /* No non-entry in this list element. */
103 _dl_close (void *_map
)
107 struct link_map
**rellist
;
108 unsigned int nrellist
;
109 struct reldep_list
*next
;
111 struct link_map
**list
;
112 struct link_map
*map
= _map
;
114 unsigned int *new_opencount
;
116 bool any_tls
= false;
119 /* First see whether we can remove the object at all. */
120 if (__builtin_expect (map
->l_flags_1
& DF_1_NODELETE
, 0)
121 && map
->l_init_called
)
122 /* Nope. Do nothing. */
125 if (__builtin_expect (map
->l_opencount
, 1) == 0)
126 _dl_signal_error (0, map
->l_name
, NULL
, N_("shared object not open"));
128 /* Acquire the lock. */
129 __libc_lock_lock_recursive (GL(dl_load_lock
));
131 /* Decrement the reference count. */
132 if (map
->l_opencount
> 1 || map
->l_type
!= lt_loaded
)
134 /* There are still references to this object. Do nothing more. */
135 if (__builtin_expect (GL(dl_debug_mask
) & DL_DEBUG_FILES
, 0))
136 _dl_debug_printf ("\nclosing file=%s; opencount == %u\n",
137 map
->l_name
, map
->l_opencount
);
139 /* One decrement the object itself, not the dependencies. */
142 __libc_lock_unlock_recursive (GL(dl_load_lock
));
146 list
= map
->l_initfini
;
148 /* Compute the new l_opencount values. */
149 i
= map
->l_searchlist
.r_nlist
;
150 if (__builtin_expect (i
== 0, 0))
151 /* This can happen if we handle relocation dependencies for an
152 object which wasn't loaded directly. */
153 for (i
= 1; list
[i
] != NULL
; ++i
)
156 new_opencount
= (unsigned int *) alloca (i
* sizeof (unsigned int));
158 for (i
= 0; list
[i
] != NULL
; ++i
)
161 new_opencount
[i
] = list
[i
]->l_opencount
;
164 for (i
= 1; list
[i
] != NULL
; ++i
)
165 if ((! (list
[i
]->l_flags_1
& DF_1_NODELETE
) || ! list
[i
]->l_init_called
)
166 /* Decrement counter. */
167 && --new_opencount
[i
] == 0
168 /* Test whether this object was also loaded directly. */
169 && list
[i
]->l_searchlist
.r_list
!= NULL
)
171 /* In this case we have the decrement all the dependencies of
172 this object. They are all in MAP's dependency list. */
174 struct link_map
**dep_list
= list
[i
]->l_searchlist
.r_list
;
176 for (j
= 1; j
< list
[i
]->l_searchlist
.r_nlist
; ++j
)
177 if (! (dep_list
[j
]->l_flags_1
& DF_1_NODELETE
)
178 || ! dep_list
[j
]->l_init_called
)
180 assert (dep_list
[j
]->l_idx
< map
->l_searchlist
.r_nlist
);
181 --new_opencount
[dep_list
[j
]->l_idx
];
184 assert (new_opencount
[0] == 0);
186 /* Call all termination functions at once. */
187 for (i
= 0; list
[i
] != NULL
; ++i
)
189 struct link_map
*imap
= list
[i
];
190 if (new_opencount
[i
] == 0 && imap
->l_type
== lt_loaded
191 && (imap
->l_info
[DT_FINI
] || imap
->l_info
[DT_FINI_ARRAY
])
192 && (! (imap
->l_flags_1
& DF_1_NODELETE
) || ! imap
->l_init_called
)
193 /* Skip any half-cooked objects that were never initialized. */
194 && imap
->l_init_called
)
196 /* When debugging print a message first. */
197 if (__builtin_expect (GL(dl_debug_mask
) & DL_DEBUG_IMPCALLS
, 0))
198 _dl_debug_printf ("\ncalling fini: %s\n\n", imap
->l_name
);
200 /* Call its termination function. */
201 if (imap
->l_info
[DT_FINI_ARRAY
] != NULL
)
204 (ElfW(Addr
) *) (imap
->l_addr
205 + imap
->l_info
[DT_FINI_ARRAY
]->d_un
.d_ptr
);
206 unsigned int sz
= (imap
->l_info
[DT_FINI_ARRAYSZ
]->d_un
.d_val
207 / sizeof (ElfW(Addr
)));
210 for (cnt
= 0; cnt
< sz
; ++cnt
)
211 ((fini_t
) (imap
->l_addr
+ array
[cnt
])) ();
214 /* Next try the old-style destructor. */
215 if (imap
->l_info
[DT_FINI
] != NULL
)
216 (*(void (*) (void)) DL_DT_FINI_ADDRESS
217 (imap
, (void *) imap
->l_addr
218 + imap
->l_info
[DT_FINI
]->d_un
.d_ptr
)) ();
220 else if (new_opencount
[i
] != 0 && imap
->l_type
== lt_loaded
)
222 /* The object is still used. But the object we are unloading
223 right now is responsible for loading it and therefore we
224 have the search list of the current object in its scope.
226 struct r_scope_elem
**runp
= imap
->l_scope
;
228 while (*runp
!= NULL
)
229 if (*runp
== &map
->l_searchlist
)
231 /* Copy all later elements. */
232 while ((runp
[0] = runp
[1]) != NULL
)
240 /* Store the new l_opencount value. */
241 imap
->l_opencount
= new_opencount
[i
];
242 /* Just a sanity check. */
243 assert (imap
->l_type
== lt_loaded
|| imap
->l_opencount
> 0);
246 /* Notify the debugger we are about to remove some loaded objects. */
247 _r_debug
.r_state
= RT_DELETE
;
250 /* Check each element of the search list to see if all references to
252 for (i
= 0; list
[i
] != NULL
; ++i
)
254 struct link_map
*imap
= list
[i
];
255 if (imap
->l_opencount
== 0 && imap
->l_type
== lt_loaded
)
257 struct libname_list
*lnp
;
259 /* That was the last reference, and this was a dlopen-loaded
260 object. We can unmap it. */
261 if (__builtin_expect (imap
->l_global
, 0))
263 /* This object is in the global scope list. Remove it. */
264 unsigned int cnt
= GL(dl_main_searchlist
)->r_nlist
;
268 while (GL(dl_main_searchlist
)->r_list
[cnt
] != imap
);
270 /* The object was already correctly registered. */
271 while (++cnt
< GL(dl_main_searchlist
)->r_nlist
)
272 GL(dl_main_searchlist
)->r_list
[cnt
- 1]
273 = GL(dl_main_searchlist
)->r_list
[cnt
];
275 --GL(dl_main_searchlist
)->r_nlist
;
279 /* Remove the object from the dtv slotinfo array if it uses TLS. */
280 if (__builtin_expect (imap
->l_tls_blocksize
> 0, 0))
284 if (! remove_slotinfo (imap
->l_tls_modid
,
285 GL(dl_tls_dtv_slotinfo_list
), 0,
286 imap
->l_init_called
))
287 /* All dynamically loaded modules with TLS are unloaded. */
288 GL(dl_tls_max_dtv_idx
) = GL(dl_tls_static_nelem
);
292 /* We can unmap all the maps at once. We determined the
293 start address and length when we loaded the object and
294 the `munmap' call does the rest. */
297 /* Finally, unlink the data structure and free it. */
299 /* We will unlink the first object only if this is a statically
301 assert (imap
->l_prev
!= NULL
);
302 imap
->l_prev
->l_next
= imap
->l_next
;
304 if (imap
->l_prev
!= NULL
)
305 imap
->l_prev
->l_next
= imap
->l_next
;
307 GL(dl_loaded
) = imap
->l_next
;
311 imap
->l_next
->l_prev
= imap
->l_prev
;
313 if (imap
->l_versions
!= NULL
)
314 free (imap
->l_versions
);
315 if (imap
->l_origin
!= NULL
&& imap
->l_origin
!= (char *) -1)
316 free ((char *) imap
->l_origin
);
318 /* If the object has relocation dependencies save this
319 information for latter. */
320 if (__builtin_expect (imap
->l_reldeps
!= NULL
, 0))
322 struct reldep_list
*newrel
;
324 newrel
= (struct reldep_list
*) alloca (sizeof (*reldeps
));
325 newrel
->rellist
= imap
->l_reldeps
;
326 newrel
->nrellist
= imap
->l_reldepsact
;
327 newrel
->next
= reldeps
;
332 /* This name always is allocated. */
334 /* Remove the list with all the names of the shared object. */
335 lnp
= imap
->l_libname
;
338 struct libname_list
*this = lnp
;
340 if (!this->dont_free
)
345 /* Remove the searchlists. */
347 free (imap
->l_initfini
);
349 /* Remove the scope array if we allocated it. */
350 if (imap
->l_scope
!= imap
->l_scope_mem
)
351 free (imap
->l_scope
);
353 if (imap
->l_phdr_allocated
)
354 free ((void *) imap
->l_phdr
);
356 if (imap
->l_rpath_dirs
.dirs
!= (void *) -1)
357 free (imap
->l_rpath_dirs
.dirs
);
358 if (imap
->l_runpath_dirs
.dirs
!= (void *) -1)
359 free (imap
->l_runpath_dirs
.dirs
);
366 /* If we removed any object which uses TLS bumnp the generation
369 if (__builtin_expect (++GL(dl_tls_generation
) == 0, 0))
370 __libc_fatal (_("TLS generation counter wrapped! Please send report with the 'glibcbug' script."));
373 /* Notify the debugger those objects are finalized and gone. */
374 _r_debug
.r_state
= RT_CONSISTENT
;
377 /* Now we can perhaps also remove the modules for which we had
378 dependencies because of symbol lookup. */
379 while (__builtin_expect (reldeps
!= NULL
, 0))
381 while (reldeps
->nrellist
-- > 0)
382 _dl_close (reldeps
->rellist
[reldeps
->nrellist
]);
384 free (reldeps
->rellist
);
386 reldeps
= reldeps
->next
;
391 /* Release the lock. */
392 __libc_lock_unlock_recursive (GL(dl_load_lock
));
394 libc_hidden_def (_dl_close
)
399 free_slotinfo (struct dtv_slotinfo_list
*elemp
)
404 /* Nothing here, all is removed (or there never was anything). */
407 if (!free_slotinfo (elemp
->next
))
408 /* We cannot free the entry. */
411 /* The least we could do is remove next element (if there was any). */
414 for (cnt
= 0; cnt
< elemp
->len
; ++cnt
)
415 if (elemp
->slotinfo
[cnt
].map
!= NULL
)
419 /* We can remove the list element. */
430 if (__builtin_expect (GL(dl_global_scope_alloc
), 0) != 0
431 && GL(dl_main_searchlist
)->r_nlist
== GL(dl_initial_searchlist
).r_nlist
)
433 /* All object dynamically loaded by the program are unloaded. Free
434 the memory allocated for the global scope variable. */
435 struct link_map
**old
= GL(dl_main_searchlist
)->r_list
;
437 /* Put the old map in. */
438 GL(dl_main_searchlist
)->r_list
= GL(dl_initial_searchlist
).r_list
;
439 /* Signal that the original map is used. */
440 GL(dl_global_scope_alloc
) = 0;
442 /* Now free the old map. */
447 /* Free the memory allocated for the dtv slotinfo array. We can do
448 this only if all modules which used this memory are unloaded.
449 Also, the first element of the list does not have to be
450 deallocated. It was allocated in the dynamic linker (i.e., with
451 a different malloc). */
452 if (free_slotinfo (GL(dl_tls_dtv_slotinfo_list
)->next
))
453 GL(dl_tls_dtv_slotinfo_list
)->next
= NULL
;
456 text_set_element (__libc_subfreeres
, free_mem
);
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