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glibc  2.9
Classes | Defines | Functions | Variables
dlfcn.h File Reference
#include <dlfcn/dlfcn.h>
#include <link.h>
#include <stdbool.h>

Go to the source code of this file.

Classes

struct  dlfcn_hook

Defines

#define __RTLD_DLOPEN   0x80000000
#define __RTLD_SPROF   0x40000000
#define __RTLD_OPENEXEC   0x20000000
#define __RTLD_CALLMAP   0x10000000
#define __RTLD_AUDIT   0x08000000
#define __LM_ID_CALLER   -2
#define __dlfcn_argc   __libc_argc
#define __dlfcn_argv   __libc_argv
#define __libc_dlopen(name)   __libc_dlopen_mode (name, RTLD_LAZY | __RTLD_DLOPEN)
#define DL_CALLER_DECL   , void *dl_caller
#define DL_CALLER   dl_caller

Functions

void * __libc_dlopen_mode (__const char *__name, int __mode)
void * __libc_dlsym (void *__map, __const char *__name)
int __libc_dlclose (void *__map)
 libc_hidden_proto (__libc_dlopen_mode) libc_hidden_proto(__libc_dlsym) libc_hidden_proto(__libc_dlclose) struct link_map
void _dl_close (void *map) attribute_hidden
void _dl_close_worker (struct link_map *map) attribute_hidden
void * _dl_sym (void *handle, const char *name, void *who) internal_function
void * _dl_vsym (void *handle, const char *name, const char *version, void *who) internal_function
int _dl_catch_error (const char **objname, const char **errstring, bool *mallocedp, void(*operate)(void *), void *args) internal_function
int _dlerror_run (void(*operate)(void *), void *args) internal_function
 libdl_hidden_proto (_dlfcn_hook) extern void *__dlopen(const char *file
void * __dlmopen (Lmid_t nsid, const char *file, int mode DL_CALLER_DECL) attribute_hidden
int __dlclose (void *handle) attribute_hidden
void * __dlsym (void *handle, const char *name DL_CALLER_DECL) attribute_hidden
void * __dlvsym (void *handle, const char *name, const char *version DL_CALLER_DECL) attribute_hidden
char * __dlerror (void) attribute_hidden
int __dladdr (const void *address, Dl_info *info) attribute_hidden
int __dladdr1 (const void *address, Dl_info *info, void **extra_info, int flags) attribute_hidden
int __dlinfo (void *handle, int request, void *arg DL_CALLER_DECL) attribute_hidden
void * __libc_dlsym_private (struct link_map *map, const char *name) attribute_hidden
void __libc_register_dl_open_hook (struct link_map *map) attribute_hidden
void __libc_register_dlfcn_hook (struct link_map *map) attribute_hidden

Variables

int __libc_argc attribute_hidden
struct dlfcn_hook_dlfcn_hook

Define Documentation

#define __dlfcn_argc   __libc_argc

Definition at line 24 of file dlfcn.h.

#define __dlfcn_argv   __libc_argv

Definition at line 25 of file dlfcn.h.

Definition at line 31 of file dlfcn.h.

#define __LM_ID_CALLER   -2

Definition at line 13 of file dlfcn.h.

#define __RTLD_AUDIT   0x08000000

Definition at line 11 of file dlfcn.h.

#define __RTLD_CALLMAP   0x10000000

Definition at line 10 of file dlfcn.h.

#define __RTLD_DLOPEN   0x80000000

Definition at line 7 of file dlfcn.h.

#define __RTLD_OPENEXEC   0x20000000

Definition at line 9 of file dlfcn.h.

#define __RTLD_SPROF   0x40000000

Definition at line 8 of file dlfcn.h.

#define DL_CALLER   dl_caller

Definition at line 95 of file dlfcn.h.

#define DL_CALLER_DECL   , void *dl_caller

Definition at line 94 of file dlfcn.h.


Function Documentation

int __dladdr ( const void *  address,
Dl_info *  info 
)

Definition at line 34 of file dladdr.c.

{
# ifdef SHARED
  if (__builtin_expect (_dlfcn_hook != NULL, 0))
    return _dlfcn_hook->dladdr (address, info);
# endif
  return _dl_addr (address, info, NULL, NULL);
}

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int __dladdr1 ( const void *  address,
Dl_info *  info,
void **  extra_info,
int  flags 
)

Definition at line 33 of file dladdr1.c.

{
# ifdef SHARED
  if (__builtin_expect (_dlfcn_hook != NULL, 0))
    return _dlfcn_hook->dladdr1 (address, info, extra, flags);
# endif

  switch (flags)
    {
    default:                /* Make this an error?  */
    case 0:
      return _dl_addr (address, info, NULL, NULL);
    case RTLD_DL_SYMENT:
      return _dl_addr (address, info, NULL, (const ElfW(Sym) **) extra);
    case RTLD_DL_LINKMAP:
      return _dl_addr (address, info, (struct link_map **) extra, NULL);
    }
}

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int __dlclose ( void *  handle)

Definition at line 41 of file dlclose.c.

{
# ifdef SHARED
  if (__builtin_expect (_dlfcn_hook != NULL, 0))
    return _dlfcn_hook->dlclose (handle);
# endif

  return _dlerror_run (dlclose_doit, handle) ? -1 : 0;
}

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char* __dlerror ( void  )

Definition at line 61 of file dlerror.c.

{
  char *buf = NULL;
  struct dl_action_result *result;

# ifdef SHARED
  if (__builtin_expect (_dlfcn_hook != NULL, 0))
    return _dlfcn_hook->dlerror ();
# endif

  /* If we have not yet initialized the buffer do it now.  */
  __libc_once (once, init);

  /* Get error string.  */
  result = (struct dl_action_result *) __libc_getspecific (key);
  if (result == NULL)
    result = &last_result;

  /* Test whether we already returned the string.  */
  if (result->returned != 0)
    {
      /* We can now free the string.  */
      if (result->errstring != NULL)
       {
         if (strcmp (result->errstring, "out of memory") != 0)
           free ((char *) result->errstring);
         result->errstring = NULL;
       }
    }
  else if (result->errstring != NULL)
    {
      buf = (char *) result->errstring;
      int n;
      if (result->errcode == 0)
       n = __asprintf (&buf, "%s%s%s",
                     result->objname,
                     result->objname[0] == '\0' ? "" : ": ",
                     _(result->errstring));
      else
       n = __asprintf (&buf, "%s%s%s: %s",
                     result->objname,
                     result->objname[0] == '\0' ? "" : ": ",
                     _(result->errstring),
                     strerror (result->errcode));
      if (n != -1)
       {
         /* We don't need the error string anymore.  */
         if (strcmp (result->errstring, "out of memory") != 0)
           free ((char *) result->errstring);
         result->errstring = buf;
       }

      /* Mark the error as returned.  */
      result->returned = 1;
    }

  return buf;
}

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int __dlinfo ( void *  handle,
int  request,
void *arg  DL_CALLER_DECL 
)

Definition at line 112 of file dlinfo.c.

{
# ifdef SHARED
  if (__builtin_expect (_dlfcn_hook != NULL, 0))
    return _dlfcn_hook->dlinfo (handle, request, arg,
                            DL_CALLER);
# endif

  struct dlinfo_args args = { (ElfW(Addr)) DL_CALLER,
                           handle, request, arg };
  return _dlerror_run (&dlinfo_doit, &args) ? -1 : 0;
}

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void* __dlmopen ( Lmid_t  nsid,
const char *  file,
int mode  DL_CALLER_DECL 
)

Definition at line 80 of file dlmopen.c.

{
# ifdef SHARED
  if (__builtin_expect (_dlfcn_hook != NULL, 0))
    return _dlfcn_hook->dlmopen (nsid, file, mode, RETURN_ADDRESS (0));
# endif

  struct dlmopen_args args;
  args.nsid = nsid;
  args.file = file;
  args.mode = mode;
  args.caller = DL_CALLER;

# ifdef SHARED
  return _dlerror_run (dlmopen_doit, &args) ? NULL : args.new;
# else
  if (_dlerror_run (dlmopen_doit, &args))
    return NULL;

  __libc_register_dl_open_hook ((struct link_map *) args.new);
  __libc_register_dlfcn_hook ((struct link_map *) args.new);

  return args.new;
# endif
}

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void* __dlsym ( void *  handle,
const char *name  DL_CALLER_DECL 
)

Definition at line 56 of file dlsym.c.

{
# ifdef SHARED
  if (__builtin_expect (_dlfcn_hook != NULL, 0))
    return _dlfcn_hook->dlsym (handle, name, DL_CALLER);
# endif

  struct dlsym_args args;
  args.who = DL_CALLER;
  args.handle = handle;
  args.name = name;

  /* Protect against concurrent loads and unloads.  */
  __rtld_lock_lock_recursive (GL(dl_load_lock));

  void *result = (_dlerror_run (dlsym_doit, &args) ? NULL : args.sym);

  __rtld_lock_unlock_recursive (GL(dl_load_lock));

  return result;
}

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void* __dlvsym ( void *  handle,
const char *  name,
const char *version  DL_CALLER_DECL 
)
int __libc_dlclose ( void *  __map)

Definition at line 37 of file dl-libc.c.

{
  _dl_close (map);
  return 0;
}

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void* __libc_dlopen_mode ( __const char *  __name,
int  __mode 
)
void* __libc_dlsym ( void *  __map,
__const char *  __name 
)
void* __libc_dlsym_private ( struct link_map map,
const char *  name 
)

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void __libc_register_dl_open_hook ( struct link_map map)

Definition at line 186 of file dl-libc.c.

{
  struct dl_open_hook **hook;

  hook = (struct dl_open_hook **) __libc_dlsym_private (map, "_dl_open_hook");
  if (hook != NULL)
    *hook = &_dl_open_hook;
}

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void __libc_register_dlfcn_hook ( struct link_map map)

Definition at line 243 of file dlerror.c.

{
  struct dlfcn_hook **hook;

  hook = (struct dlfcn_hook **) __libc_dlsym_private (map, "_dlfcn_hook");
  if (hook != NULL)
    *hook = &_dlfcn_hooks;
}

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int _dl_catch_error ( const char **  objname,
const char **  errstring,
bool *  mallocedp,
void(*)(void *)  operate,
void *  args 
)

Definition at line 158 of file dl-error.c.

{
  int errcode;
  struct catch *volatile old;
  struct catch c;
  /* We need not handle `receiver' since setting a `catch' is handled
     before it.  */

  /* Some systems (e.g., SPARC) handle constructors to local variables
     inefficient.  So we initialize `c' by hand.  */
  c.errstring = NULL;

  struct catch **const catchp = &CATCH_HOOK;
  old = *catchp;
  /* Do not save the signal mask.  */
  errcode = __sigsetjmp (c.env, 0);
  if (__builtin_expect (errcode, 0) == 0)
    {
      *catchp = &c;
      (*operate) (args);
      *catchp = old;
      *objname = NULL;
      *errstring = NULL;
      *mallocedp = false;
      return 0;
    }

  /* We get here only if we longjmp'd out of OPERATE.  */
  *catchp = old;
  *objname = c.objname;
  *errstring = c.errstring;
  *mallocedp = c.malloced;
  return errcode == -1 ? 0 : errcode;
}

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void _dl_close ( void *  map)

Definition at line 712 of file dl-close.c.

{
  struct link_map *map = _map;

  /* First see whether we can remove the object at all.  */
  if (__builtin_expect (map->l_flags_1 & DF_1_NODELETE, 0))
    {
      assert (map->l_init_called);
      /* Nope.  Do nothing.  */
      return;
    }

  if (__builtin_expect (map->l_direct_opencount, 1) == 0)
    GLRO(dl_signal_error) (0, map->l_name, NULL, N_("shared object not open"));

  /* Acquire the lock.  */
  __rtld_lock_lock_recursive (GL(dl_load_lock));

  _dl_close_worker (map);

  __rtld_lock_unlock_recursive (GL(dl_load_lock));
}

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void _dl_close_worker ( struct link_map map)

Definition at line 109 of file dl-close.c.

{
  /* One less direct use.  */
  --map->l_direct_opencount;

  /* If _dl_close is called recursively (some destructor call dlclose),
     just record that the parent _dl_close will need to do garbage collection
     again and return.  */
  static enum { not_pending, pending, rerun } dl_close_state;

  if (map->l_direct_opencount > 0 || map->l_type != lt_loaded
      || dl_close_state != not_pending)
    {
      if (map->l_direct_opencount == 0 && map->l_type == lt_loaded)
       dl_close_state = rerun;

      /* There are still references to this object.  Do nothing more.  */
      if (__builtin_expect (GLRO(dl_debug_mask) & DL_DEBUG_FILES, 0))
       _dl_debug_printf ("\nclosing file=%s; direct_opencount=%u\n",
                       map->l_name, map->l_direct_opencount);

      return;
    }

  Lmid_t nsid = map->l_ns;
  struct link_namespaces *ns = &GL(dl_ns)[nsid];

 retry:
  dl_close_state = pending;

  bool any_tls = false;
  const unsigned int nloaded = ns->_ns_nloaded;
  char used[nloaded];
  char done[nloaded];
  struct link_map *maps[nloaded];

  /* Run over the list and assign indexes to the link maps and enter
     them into the MAPS array.  */
  int idx = 0;
  for (struct link_map *l = ns->_ns_loaded; l != NULL; l = l->l_next)
    {
      l->l_idx = idx;
      maps[idx] = l;
      ++idx;
    }
  assert (idx == nloaded);

  /* Prepare the bitmaps.  */
  memset (used, '\0', sizeof (used));
  memset (done, '\0', sizeof (done));

  /* Keep track of the lowest index link map we have covered already.  */
  int done_index = -1;
  while (++done_index < nloaded)
    {
      struct link_map *l = maps[done_index];

      if (done[done_index])
       /* Already handled.  */
       continue;

      /* Check whether this object is still used.  */
      if (l->l_type == lt_loaded
         && l->l_direct_opencount == 0
         && (l->l_flags_1 & DF_1_NODELETE) == 0
         && !used[done_index])
       continue;

      /* We need this object and we handle it now.  */
      done[done_index] = 1;
      used[done_index] = 1;
      /* Signal the object is still needed.  */
      l->l_idx = IDX_STILL_USED;

      /* Mark all dependencies as used.  */
      if (l->l_initfini != NULL)
       {
         struct link_map **lp = &l->l_initfini[1];
         while (*lp != NULL)
           {
             if ((*lp)->l_idx != IDX_STILL_USED)
              {
                assert ((*lp)->l_idx >= 0 && (*lp)->l_idx < nloaded);

                if (!used[(*lp)->l_idx])
                  {
                    used[(*lp)->l_idx] = 1;
                    if ((*lp)->l_idx - 1 < done_index)
                     done_index = (*lp)->l_idx - 1;
                  }
              }

             ++lp;
           }
       }
      /* And the same for relocation dependencies.  */
      if (l->l_reldeps != NULL)
       for (unsigned int j = 0; j < l->l_reldeps->act; ++j)
         {
           struct link_map *jmap = l->l_reldeps->list[j];

           if (jmap->l_idx != IDX_STILL_USED)
             {
              assert (jmap->l_idx >= 0 && jmap->l_idx < nloaded);

              if (!used[jmap->l_idx])
                {
                  used[jmap->l_idx] = 1;
                  if (jmap->l_idx - 1 < done_index)
                    done_index = jmap->l_idx - 1;
                }
             }
         }
    }

  /* Sort the entries.  */
  _dl_sort_fini (ns->_ns_loaded, maps, nloaded, used, nsid);

  /* Call all termination functions at once.  */
#ifdef SHARED
  bool do_audit = GLRO(dl_naudit) > 0 && !ns->_ns_loaded->l_auditing;
#endif
  bool unload_any = false;
  bool scope_mem_left = false;
  unsigned int unload_global = 0;
  unsigned int first_loaded = ~0;
  for (unsigned int i = 0; i < nloaded; ++i)
    {
      struct link_map *imap = maps[i];

      /* All elements must be in the same namespace.  */
      assert (imap->l_ns == nsid);

      if (!used[i])
       {
         assert (imap->l_type == lt_loaded
                && (imap->l_flags_1 & DF_1_NODELETE) == 0);

         /* Call its termination function.  Do not do it for
            half-cooked objects.  */
         if (imap->l_init_called)
           {
             /* When debugging print a message first.  */
             if (__builtin_expect (GLRO(dl_debug_mask) & DL_DEBUG_IMPCALLS,
                                0))
              _dl_debug_printf ("\ncalling fini: %s [%lu]\n\n",
                              imap->l_name, nsid);

             if (imap->l_info[DT_FINI_ARRAY] != NULL)
              {
                ElfW(Addr) *array =
                  (ElfW(Addr) *) (imap->l_addr
                                + imap->l_info[DT_FINI_ARRAY]->d_un.d_ptr);
                unsigned int sz = (imap->l_info[DT_FINI_ARRAYSZ]->d_un.d_val
                                 / sizeof (ElfW(Addr)));

                while (sz-- > 0)
                  ((fini_t) array[sz]) ();
              }

             /* Next try the old-style destructor.  */
             if (imap->l_info[DT_FINI] != NULL)
              (*(void (*) (void)) DL_DT_FINI_ADDRESS
               (imap, ((void *) imap->l_addr
                      + imap->l_info[DT_FINI]->d_un.d_ptr))) ();
           }

#ifdef SHARED
         /* Auditing checkpoint: we have a new object.  */
         if (__builtin_expect (do_audit, 0))
           {
             struct audit_ifaces *afct = GLRO(dl_audit);
             for (unsigned int cnt = 0; cnt < GLRO(dl_naudit); ++cnt)
              {
                if (afct->objclose != NULL)
                  /* Return value is ignored.  */
                  (void) afct->objclose (&imap->l_audit[cnt].cookie);

                afct = afct->next;
              }
           }
#endif

         /* This object must not be used anymore.  */
         imap->l_removed = 1;

         /* We indeed have an object to remove.  */
         unload_any = true;

         if (imap->l_global)
           ++unload_global;

         /* Remember where the first dynamically loaded object is.  */
         if (i < first_loaded)
           first_loaded = i;
       }
      /* Else used[i].  */
      else if (imap->l_type == lt_loaded)
       {
         struct r_scope_elem *new_list = NULL;

         if (imap->l_searchlist.r_list == NULL && imap->l_initfini != NULL)
           {
             /* The object is still used.  But one of the objects we are
               unloading right now is responsible for loading it.  If
               the current object does not have it's own scope yet we
               have to create one.  This has to be done before running
               the finalizers.

               To do this count the number of dependencies.  */
             unsigned int cnt;
             for (cnt = 1; imap->l_initfini[cnt] != NULL; ++cnt)
              ;

             /* We simply reuse the l_initfini list.  */
             imap->l_searchlist.r_list = &imap->l_initfini[cnt + 1];
             imap->l_searchlist.r_nlist = cnt;

             new_list = &imap->l_searchlist;
           }

         /* Count the number of scopes which remain after the unload.
            When we add the local search list count it.  Always add
            one for the terminating NULL pointer.  */
         size_t remain = (new_list != NULL) + 1;
         bool removed_any = false;
         for (size_t cnt = 0; imap->l_scope[cnt] != NULL; ++cnt)
           /* This relies on l_scope[] entries being always set either
              to its own l_symbolic_searchlist address, or some map's
              l_searchlist address.  */
           if (imap->l_scope[cnt] != &imap->l_symbolic_searchlist)
             {
              struct link_map *tmap = (struct link_map *)
                ((char *) imap->l_scope[cnt]
                 - offsetof (struct link_map, l_searchlist));
              assert (tmap->l_ns == nsid);
              if (tmap->l_idx == IDX_STILL_USED)
                ++remain;
              else
                removed_any = true;
             }
           else
             ++remain;

         if (removed_any)
           {
             /* Always allocate a new array for the scope.  This is
               necessary since we must be able to determine the last
               user of the current array.  If possible use the link map's
               memory.  */
             size_t new_size;
             struct r_scope_elem **newp;

#define SCOPE_ELEMS(imap) \
  (sizeof (imap->l_scope_mem) / sizeof (imap->l_scope_mem[0]))

             if (imap->l_scope != imap->l_scope_mem
                && remain < SCOPE_ELEMS (imap))
              {
                new_size = SCOPE_ELEMS (imap);
                newp = imap->l_scope_mem;
              }
             else
              {
                new_size = imap->l_scope_max;
                newp = (struct r_scope_elem **)
                  malloc (new_size * sizeof (struct r_scope_elem *));
                if (newp == NULL)
                  _dl_signal_error (ENOMEM, "dlclose", NULL,
                                  N_("cannot create scope list"));
              }

             /* Copy over the remaining scope elements.  */
             remain = 0;
             for (size_t cnt = 0; imap->l_scope[cnt] != NULL; ++cnt)
              {
                if (imap->l_scope[cnt] != &imap->l_symbolic_searchlist)
                  {
                    struct link_map *tmap = (struct link_map *)
                     ((char *) imap->l_scope[cnt]
                      - offsetof (struct link_map, l_searchlist));
                    if (tmap->l_idx != IDX_STILL_USED)
                     {
                       /* Remove the scope.  Or replace with own map's
                          scope.  */
                       if (new_list != NULL)
                         {
                           newp[remain++] = new_list;
                           new_list = NULL;
                         }
                       continue;
                     }
                  }

                newp[remain++] = imap->l_scope[cnt];
              }
             newp[remain] = NULL;

             struct r_scope_elem **old = imap->l_scope;

             imap->l_scope = newp;

             /* No user anymore, we can free it now.  */
             if (old != imap->l_scope_mem)
              {
                if (_dl_scope_free (old))
                  /* If _dl_scope_free used THREAD_GSCOPE_WAIT (),
                     no need to repeat it.  */
                  scope_mem_left = false;
              }
             else
              scope_mem_left = true;

             imap->l_scope_max = new_size;
           }

         /* The loader is gone, so mark the object as not having one.
            Note: l_idx != IDX_STILL_USED -> object will be removed.  */
         if (imap->l_loader != NULL
             && imap->l_loader->l_idx != IDX_STILL_USED)
           imap->l_loader = NULL;

         /* Remember where the first dynamically loaded object is.  */
         if (i < first_loaded)
           first_loaded = i;
       }
    }

  /* If there are no objects to unload, do nothing further.  */
  if (!unload_any)
    goto out;

#ifdef SHARED
  /* Auditing checkpoint: we will start deleting objects.  */
  if (__builtin_expect (do_audit, 0))
    {
      struct link_map *head = ns->_ns_loaded;
      struct audit_ifaces *afct = GLRO(dl_audit);
      /* Do not call the functions for any auditing object.  */
      if (head->l_auditing == 0)
       {
         for (unsigned int cnt = 0; cnt < GLRO(dl_naudit); ++cnt)
           {
             if (afct->activity != NULL)
              afct->activity (&head->l_audit[cnt].cookie, LA_ACT_DELETE);

             afct = afct->next;
           }
       }
    }
#endif

  /* Notify the debugger we are about to remove some loaded objects.  */
  struct r_debug *r = _dl_debug_initialize (0, nsid);
  r->r_state = RT_DELETE;
  _dl_debug_state ();

  if (unload_global)
    {
      /* Some objects are in the global scope list.  Remove them.  */
      struct r_scope_elem *ns_msl = ns->_ns_main_searchlist;
      unsigned int i;
      unsigned int j = 0;
      unsigned int cnt = ns_msl->r_nlist;

      while (cnt > 0 && ns_msl->r_list[cnt - 1]->l_removed)
       --cnt;

      if (cnt + unload_global == ns_msl->r_nlist)
       /* Speed up removing most recently added objects.  */
       j = cnt;
      else
       for (i = 0; i < cnt; i++)
         if (ns_msl->r_list[i]->l_removed == 0)
           {
             if (i != j)
              ns_msl->r_list[j] = ns_msl->r_list[i];
             j++;
           }
      ns_msl->r_nlist = j;
    }

  if (!RTLD_SINGLE_THREAD_P
      && (unload_global
         || scope_mem_left
         || (GL(dl_scope_free_list) != NULL
             && GL(dl_scope_free_list)->count)))
    {
      THREAD_GSCOPE_WAIT ();

      /* Now we can free any queued old scopes.  */
      struct dl_scope_free_list *fsl = GL(dl_scope_free_list);
      if (fsl != NULL)
       while (fsl->count > 0)
         free (fsl->list[--fsl->count]);
    }

  size_t tls_free_start;
  size_t tls_free_end;
  tls_free_start = tls_free_end = NO_TLS_OFFSET;

  /* Check each element of the search list to see if all references to
     it are gone.  */
  for (unsigned int i = first_loaded; i < nloaded; ++i)
    {
      struct link_map *imap = maps[i];
      if (!used[i])
       {
         assert (imap->l_type == lt_loaded);

         /* That was the last reference, and this was a dlopen-loaded
            object.  We can unmap it.  */

         /* Remove the object from the dtv slotinfo array if it uses TLS.  */
         if (__builtin_expect (imap->l_tls_blocksize > 0, 0))
           {
             any_tls = true;

             if (GL(dl_tls_dtv_slotinfo_list) != NULL
                && ! remove_slotinfo (imap->l_tls_modid,
                                   GL(dl_tls_dtv_slotinfo_list), 0,
                                   imap->l_init_called))
              /* All dynamically loaded modules with TLS are unloaded.  */
              GL(dl_tls_max_dtv_idx) = GL(dl_tls_static_nelem);

             if (imap->l_tls_offset != NO_TLS_OFFSET
                && imap->l_tls_offset != FORCED_DYNAMIC_TLS_OFFSET)
              {
                /* Collect a contiguous chunk built from the objects in
                   this search list, going in either direction.  When the
                   whole chunk is at the end of the used area then we can
                   reclaim it.  */
#if TLS_TCB_AT_TP
                if (tls_free_start == NO_TLS_OFFSET
                    || (size_t) imap->l_tls_offset == tls_free_start)
                  {
                    /* Extend the contiguous chunk being reclaimed.  */
                    tls_free_start
                     = imap->l_tls_offset - imap->l_tls_blocksize;

                    if (tls_free_end == NO_TLS_OFFSET)
                     tls_free_end = imap->l_tls_offset;
                  }
                else if (imap->l_tls_offset - imap->l_tls_blocksize
                        == tls_free_end)
                  /* Extend the chunk backwards.  */
                  tls_free_end = imap->l_tls_offset;
                else
                  {
                    /* This isn't contiguous with the last chunk freed.
                      One of them will be leaked unless we can free
                      one block right away.  */
                    if (tls_free_end == GL(dl_tls_static_used))
                     {
                       GL(dl_tls_static_used) = tls_free_start;
                       tls_free_end = imap->l_tls_offset;
                       tls_free_start
                         = tls_free_end - imap->l_tls_blocksize;
                     }
                    else if ((size_t) imap->l_tls_offset
                            == GL(dl_tls_static_used))
                     GL(dl_tls_static_used)
                       = imap->l_tls_offset - imap->l_tls_blocksize;
                    else if (tls_free_end < (size_t) imap->l_tls_offset)
                     {
                       /* We pick the later block.  It has a chance to
                          be freed.  */
                       tls_free_end = imap->l_tls_offset;
                       tls_free_start
                         = tls_free_end - imap->l_tls_blocksize;
                     }
                  }
#elif TLS_DTV_AT_TP
                if ((size_t) imap->l_tls_offset == tls_free_end)
                  /* Extend the contiguous chunk being reclaimed.  */
                  tls_free_end -= imap->l_tls_blocksize;
                else if (imap->l_tls_offset + imap->l_tls_blocksize
                        == tls_free_start)
                  /* Extend the chunk backwards.  */
                  tls_free_start = imap->l_tls_offset;
                else
                  {
                    /* This isn't contiguous with the last chunk freed.
                      One of them will be leaked.  */
                    if (tls_free_end == GL(dl_tls_static_used))
                     GL(dl_tls_static_used) = tls_free_start;
                    tls_free_start = imap->l_tls_offset;
                    tls_free_end = tls_free_start + imap->l_tls_blocksize;
                  }
#else
# error "Either TLS_TCB_AT_TP or TLS_DTV_AT_TP must be defined"
#endif
              }
           }

         /* We can unmap all the maps at once.  We determined the
            start address and length when we loaded the object and
            the `munmap' call does the rest.  */
         DL_UNMAP (imap);

         /* Finally, unlink the data structure and free it.  */
         if (imap->l_prev != NULL)
           imap->l_prev->l_next = imap->l_next;
         else
           {
#ifdef SHARED
             assert (nsid != LM_ID_BASE);
#endif
             ns->_ns_loaded = imap->l_next;
           }

         --ns->_ns_nloaded;
         if (imap->l_next != NULL)
           imap->l_next->l_prev = imap->l_prev;

         free (imap->l_versions);
         if (imap->l_origin != (char *) -1)
           free ((char *) imap->l_origin);

         free (imap->l_reldeps);

         /* Print debugging message.  */
         if (__builtin_expect (GLRO(dl_debug_mask) & DL_DEBUG_FILES, 0))
           _dl_debug_printf ("\nfile=%s [%lu];  destroying link map\n",
                           imap->l_name, imap->l_ns);

         /* This name always is allocated.  */
         free (imap->l_name);
         /* Remove the list with all the names of the shared object.  */

         struct libname_list *lnp = imap->l_libname;
         do
           {
             struct libname_list *this = lnp;
             lnp = lnp->next;
             if (!this->dont_free)
              free (this);
           }
         while (lnp != NULL);

         /* Remove the searchlists.  */
         free (imap->l_initfini);

         /* Remove the scope array if we allocated it.  */
         if (imap->l_scope != imap->l_scope_mem)
           free (imap->l_scope);

         if (imap->l_phdr_allocated)
           free ((void *) imap->l_phdr);

         if (imap->l_rpath_dirs.dirs != (void *) -1)
           free (imap->l_rpath_dirs.dirs);
         if (imap->l_runpath_dirs.dirs != (void *) -1)
           free (imap->l_runpath_dirs.dirs);

         free (imap);
       }
    }

  /* If we removed any object which uses TLS bump the generation counter.  */
  if (any_tls)
    {
      if (__builtin_expect (++GL(dl_tls_generation) == 0, 0))
       _dl_fatal_printf ("TLS generation counter wrapped!  Please report as described in <http://www.gnu.org/software/libc/bugs.html>.\n");

      if (tls_free_end == GL(dl_tls_static_used))
       GL(dl_tls_static_used) = tls_free_start;
    }

#ifdef SHARED
  /* Auditing checkpoint: we have deleted all objects.  */
  if (__builtin_expect (do_audit, 0))
    {
      struct link_map *head = ns->_ns_loaded;
      /* Do not call the functions for any auditing object.  */
      if (head->l_auditing == 0)
       {
         struct audit_ifaces *afct = GLRO(dl_audit);
         for (unsigned int cnt = 0; cnt < GLRO(dl_naudit); ++cnt)
           {
             if (afct->activity != NULL)
              afct->activity (&head->l_audit[cnt].cookie, LA_ACT_CONSISTENT);

             afct = afct->next;
           }
       }
    }
#endif

  /* Notify the debugger those objects are finalized and gone.  */
  r->r_state = RT_CONSISTENT;
  _dl_debug_state ();

  /* Recheck if we need to retry, release the lock.  */
 out:
  if (dl_close_state == rerun)
    goto retry;

  dl_close_state = not_pending;
}

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void* _dl_sym ( void *  handle,
const char *  name,
void *  who 
)

Definition at line 271 of file dl-sym.c.

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void* _dl_vsym ( void *  handle,
const char *  name,
const char *  version,
void *  who 
)

Definition at line 254 of file dl-sym.c.

{
  struct r_found_version vers;

  /* Compute hash value to the version string.  */
  vers.name = version;
  vers.hidden = 1;
  vers.hash = _dl_elf_hash (version);
  /* We don't have a specific file where the symbol can be found.  */
  vers.filename = NULL;

  return do_sym (handle, name, who, &vers, 0);
}

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int _dlerror_run ( void(*)(void *)  operate,
void *  args 
)

Definition at line 125 of file dlerror.c.

{
  struct dl_action_result *result;

  /* If we have not yet initialized the buffer do it now.  */
  __libc_once (once, init);

  /* Get error string and number.  */
  if (static_buf != NULL)
    result = static_buf;
  else
    {
      /* We don't use the static buffer and so we have a key.  Use it
        to get the thread-specific buffer.  */
      result = __libc_getspecific (key);
      if (result == NULL)
       {
         result = (struct dl_action_result *) calloc (1, sizeof (*result));
         if (result == NULL)
           /* We are out of memory.  Since this is no really critical
              situation we carry on by using the global variable.
              This might lead to conflicts between the threads but
              they soon all will have memory problems.  */
           result = &last_result;
         else
           /* Set the tsd.  */
           __libc_setspecific (key, result);
       }
    }

  if (result->errstring != NULL)
    {
      /* Free the error string from the last failed command.  This can
        happen if `dlerror' was not run after an error was found.  */
      if (result->malloced)
       free ((char *) result->errstring);
      result->errstring = NULL;
    }

  result->errcode = GLRO(dl_catch_error) (&result->objname, &result->errstring,
                                     &result->malloced, operate, args);

  /* If no error we mark that no error string is available.  */
  result->returned = result->errstring == NULL;

  return result->errstring != NULL;
}

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Variable Documentation

Definition at line 22 of file dlfcn.h.