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glibc  2.9
Defines | Functions
dl-object.c File Reference
#include <errno.h>
#include <string.h>
#include <stdlib.h>
#include <unistd.h>
#include <ldsodefs.h>
#include <assert.h>

Go to the source code of this file.

Defines

#define audit_space   0

Functions

struct link_map *internal_function _dl_new_object (char *realname, const char *libname, int type, struct link_map *loader, int mode, Lmid_t nsid)

Define Documentation

#define audit_space   0

Function Documentation

struct link_map* internal_function _dl_new_object ( char *  realname,
const char *  libname,
int  type,
struct link_map loader,
int  mode,
Lmid_t  nsid 
) [read]

Definition at line 34 of file dl-object.c.

{
  struct link_map *l;
  int idx;
  size_t libname_len = strlen (libname) + 1;
  struct link_map *new;
  struct libname_list *newname;
#ifdef SHARED
  /* We create the map for the executable before we know whether we have
     auditing libraries and if yes, how many.  Assume the worst.  */
  unsigned int naudit = GLRO(dl_naudit) ?: ((mode & __RTLD_OPENEXEC)
                                       ? DL_NNS : 0);
  size_t audit_space = naudit * sizeof (new->l_audit[0]);
#else
# define audit_space 0
#endif

  new = (struct link_map *) calloc (sizeof (*new) + audit_space
                                + sizeof (struct link_map *)
                                + sizeof (*newname) + libname_len, 1);
  if (new == NULL)
    return NULL;

  new->l_real = new;
  new->l_symbolic_searchlist.r_list = (struct link_map **) ((char *) (new + 1)
                                                     + audit_space);

  new->l_libname = newname
    = (struct libname_list *) (new->l_symbolic_searchlist.r_list + 1);
  newname->name = (char *) memcpy (newname + 1, libname, libname_len);
  /* newname->next = NULL;  We use calloc therefore not necessary.  */
  newname->dont_free = 1;

  new->l_name = realname;
  new->l_type = type;
  new->l_loader = loader;
#if NO_TLS_OFFSET != 0
  new->l_tls_offset = NO_TLS_OFFSET;
#endif
  new->l_ns = nsid;

#ifdef SHARED
  for (unsigned int cnt = 0; cnt < naudit; ++cnt)
    {
      new->l_audit[cnt].cookie = (uintptr_t) new;
      /* new->l_audit[cnt].bindflags = 0; */
    }
#endif

  /* new->l_global = 0;     We use calloc therefore not necessary.  */

  /* Use the 'l_scope_mem' array by default for the the 'l_scope'
     information.  If we need more entries we will allocate a large
     array dynamically.  */
  new->l_scope = new->l_scope_mem;
  new->l_scope_max = sizeof (new->l_scope_mem) / sizeof (new->l_scope_mem[0]);

  /* Counter for the scopes we have to handle.  */
  idx = 0;

  if (GL(dl_ns)[nsid]._ns_loaded != NULL)
    {
      l = GL(dl_ns)[nsid]._ns_loaded;
      while (l->l_next != NULL)
       l = l->l_next;
      new->l_prev = l;
      /* new->l_next = NULL;       Would be necessary but we use calloc.  */
      l->l_next = new;

      /* Add the global scope.  */
      new->l_scope[idx++] = &GL(dl_ns)[nsid]._ns_loaded->l_searchlist;
    }
  else
    GL(dl_ns)[nsid]._ns_loaded = new;
  ++GL(dl_ns)[nsid]._ns_nloaded;
  new->l_serial = GL(dl_load_adds);
  ++GL(dl_load_adds);

  /* If we have no loader the new object acts as it.  */
  if (loader == NULL)
    loader = new;
  else
    /* Determine the local scope.  */
    while (loader->l_loader != NULL)
      loader = loader->l_loader;

  /* Insert the scope if it isn't the global scope we already added.  */
  if (idx == 0 || &loader->l_searchlist != new->l_scope[0])
    {
      if ((mode & RTLD_DEEPBIND) != 0 && idx != 0)
       {
         new->l_scope[1] = new->l_scope[0];
         idx = 0;
       }

      new->l_scope[idx] = &loader->l_searchlist;
    }

  new->l_local_scope[0] = &new->l_searchlist;

  /* Don't try to find the origin for the main map which has the name "".  */
  if (realname[0] != '\0')
    {
      size_t realname_len = strlen (realname) + 1;
      char *origin;
      char *cp;

      if (realname[0] == '/')
       {
         /* It is an absolute path.  Use it.  But we have to make a
            copy since we strip out the trailing slash.  */
         cp = origin = (char *) malloc (realname_len);
         if (origin == NULL)
           {
             origin = (char *) -1;
             goto out;
           }
       }
      else
       {
         size_t len = realname_len;
         char *result = NULL;

         /* Get the current directory name.  */
         origin = NULL;
         do
           {
             char *new_origin;

             len += 128;
             new_origin = (char *) realloc (origin, len);
             if (new_origin == NULL)
              /* We exit the loop.  Note that result == NULL.  */
              break;
             origin = new_origin;
           }
         while ((result = __getcwd (origin, len - realname_len)) == NULL
               && errno == ERANGE);

         if (result == NULL)
           {
             /* We were not able to determine the current directory.
                Note that free(origin) is OK if origin == NULL.  */
             free (origin);
             origin = (char *) -1;
             goto out;
           }

         /* Find the end of the path and see whether we have to add a
            slash.  We could use rawmemchr but this need not be
            fast.  */
         cp = (strchr) (origin, '\0');
         if (cp[-1] != '/')
           *cp++ = '/';
       }

      /* Add the real file name.  */
      cp = __mempcpy (cp, realname, realname_len);

      /* Now remove the filename and the slash.  Leave the slash if
        the name is something like "/foo".  */
      do
       --cp;
      while (*cp != '/');

      if (cp == origin)
       /* Keep the only slash which is the first character.  */
       ++cp;
      *cp = '\0';

    out:
      new->l_origin = origin;
    }

  return new;
}

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