| /* Storage management for the chain of loaded shared objects. |
| Copyright (C) 1995-2018 Free Software Foundation, Inc. |
| This file is part of the GNU C Library. |
| |
| The GNU C Library is free software; you can redistribute it and/or |
| modify it under the terms of the GNU Lesser General Public |
| License as published by the Free Software Foundation; either |
| version 2.1 of the License, or (at your option) any later version. |
| |
| The GNU C Library is distributed in the hope that it will be useful, |
| but WITHOUT ANY WARRANTY; without even the implied warranty of |
| MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU |
| Lesser General Public License for more details. |
| |
| You should have received a copy of the GNU Lesser General Public |
| License along with the GNU C Library; if not, see |
| <http://www.gnu.org/licenses/>. */ |
| |
| #include <errno.h> |
| #include <string.h> |
| #include <stdlib.h> |
| #include <unistd.h> |
| #include <ldsodefs.h> |
| |
| #include <assert.h> |
| |
| |
| /* Add the new link_map NEW to the end of the namespace list. */ |
| void |
| _dl_add_to_namespace_list (struct link_map *new, Lmid_t nsid) |
| { |
| /* We modify the list of loaded objects. */ |
| __rtld_lock_lock_recursive (GL(dl_load_write_lock)); |
| |
| if (GL(dl_ns)[nsid]._ns_loaded != NULL) |
| { |
| struct link_map *l = _dl_last_entry (&GL(dl_ns)[nsid]); |
| new->l_prev = l; |
| /* new->l_next = NULL; Would be necessary but we use calloc. */ |
| l->l_next = new; |
| } |
| 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); |
| |
| _dl_hash_add_object (new); |
| |
| __rtld_lock_unlock_recursive (GL(dl_load_write_lock)); |
| } |
| |
| |
| /* Allocate a `struct link_map' for a new object being loaded. */ |
| struct link_map * |
| _dl_new_object (char *realname, const char *libname, int type, |
| struct link_map *loader, int mode, Lmid_t nsid) |
| { |
| 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; |
| |
| /* When we create the executable link map, or a VDSO link map, we start |
| with "" for the l_name. In these cases "" points to ld.so rodata |
| and won't get dumped during core file generation. Therefore to assist |
| gdb and to create more self-contained core files we adjust l_name to |
| point at the newly allocated copy (which will get dumped) instead of |
| the ld.so rodata copy. */ |
| new->l_name = *realname ? realname : (char *) newname->name + libname_len - 1; |
| new->l_type = type; |
| /* If we set the bit now since we know it is never used we avoid |
| dirtying the cache line later. */ |
| if ((GLRO(dl_debug_mask) & DL_DEBUG_UNUSED) == 0) |
| new->l_used = 1; |
| 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 '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. */ |
| int idx = 0; |
| |
| if (GL(dl_ns)[nsid]._ns_loaded != NULL) |
| /* Add the global scope. */ |
| new->l_scope[idx++] = &GL(dl_ns)[nsid]._ns_loaded->l_searchlist; |
| |
| /* 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; |
| } |