mirror of
https://sourceware.org/git/glibc.git
synced 2024-12-13 06:40:09 +00:00
024a7640ab
The fix for bug 19329 caused a regression such that pthread_create can
deadlock when concurrent ctors from dlopen are waiting for it to finish.
Use a new GL(dl_load_tls_lock) in pthread_create that is not taken
around ctors in dlopen.
The new lock is also used in __tls_get_addr instead of GL(dl_load_lock).
The new lock is held in _dl_open_worker and _dl_close_worker around
most of the logic before/after the init/fini routines. When init/fini
routines are running then TLS is in a consistent, usable state.
In _dl_open_worker the new lock requires catching and reraising dlopen
failures that happen in the critical section.
The new lock is reinitialized in a fork child, to keep the existing
behaviour and it is kept recursive in case malloc interposition or TLS
access from signal handlers can retake it. It is not obvious if this
is necessary or helps, but avoids changing the preexisting behaviour.
The new lock may be more appropriate for dl_iterate_phdr too than
GL(dl_load_write_lock), since TLS state of an incompletely loaded
module may be accessed. If the new lock can replace the old one,
that can be a separate change.
Fixes bug 28357.
Reviewed-by: Adhemerval Zanella <adhemerval.zanella@linaro.org>
(cherry picked from commit 83b5323261
)
976 lines
31 KiB
C
976 lines
31 KiB
C
/* Load a shared object at runtime, relocate it, and run its initializer.
|
|
Copyright (C) 1996-2021 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
|
|
<https://www.gnu.org/licenses/>. */
|
|
|
|
#include <assert.h>
|
|
#include <dlfcn.h>
|
|
#include <errno.h>
|
|
#include <libintl.h>
|
|
#include <stdio.h>
|
|
#include <stdlib.h>
|
|
#include <string.h>
|
|
#include <unistd.h>
|
|
#include <sys/mman.h> /* Check whether MAP_COPY is defined. */
|
|
#include <sys/param.h>
|
|
#include <libc-lock.h>
|
|
#include <ldsodefs.h>
|
|
#include <sysdep-cancel.h>
|
|
#include <tls.h>
|
|
#include <stap-probe.h>
|
|
#include <atomic.h>
|
|
#include <libc-internal.h>
|
|
#include <array_length.h>
|
|
#include <libc-early-init.h>
|
|
#include <gnu/lib-names.h>
|
|
|
|
#include <dl-dst.h>
|
|
#include <dl-prop.h>
|
|
|
|
|
|
/* We must be careful not to leave us in an inconsistent state. Thus we
|
|
catch any error and re-raise it after cleaning up. */
|
|
|
|
struct dl_open_args
|
|
{
|
|
const char *file;
|
|
int mode;
|
|
/* This is the caller of the dlopen() function. */
|
|
const void *caller_dlopen;
|
|
struct link_map *map;
|
|
/* Namespace ID. */
|
|
Lmid_t nsid;
|
|
|
|
/* Original value of _ns_global_scope_pending_adds. Set by
|
|
dl_open_worker. Only valid if nsid is a real namespace
|
|
(non-negative). */
|
|
unsigned int original_global_scope_pending_adds;
|
|
|
|
/* Set to true by dl_open_worker if libc.so was already loaded into
|
|
the namespace at the time dl_open_worker was called. This is
|
|
used to determine whether libc.so early initialization has
|
|
already been done before, and whether to roll back the cached
|
|
libc_map value in the namespace in case of a dlopen failure. */
|
|
bool libc_already_loaded;
|
|
|
|
/* Set to true if the end of dl_open_worker_begin was reached. */
|
|
bool worker_continue;
|
|
|
|
/* Original parameters to the program and the current environment. */
|
|
int argc;
|
|
char **argv;
|
|
char **env;
|
|
};
|
|
|
|
/* Called in case the global scope cannot be extended. */
|
|
static void __attribute__ ((noreturn))
|
|
add_to_global_resize_failure (struct link_map *new)
|
|
{
|
|
_dl_signal_error (ENOMEM, new->l_libname->name, NULL,
|
|
N_ ("cannot extend global scope"));
|
|
}
|
|
|
|
/* Grow the global scope array for the namespace, so that all the new
|
|
global objects can be added later in add_to_global_update, without
|
|
risk of memory allocation failure. add_to_global_resize raises
|
|
exceptions for memory allocation errors. */
|
|
static void
|
|
add_to_global_resize (struct link_map *new)
|
|
{
|
|
struct link_namespaces *ns = &GL (dl_ns)[new->l_ns];
|
|
|
|
/* Count the objects we have to put in the global scope. */
|
|
unsigned int to_add = 0;
|
|
for (unsigned int cnt = 0; cnt < new->l_searchlist.r_nlist; ++cnt)
|
|
if (new->l_searchlist.r_list[cnt]->l_global == 0)
|
|
++to_add;
|
|
|
|
/* The symbols of the new objects and its dependencies are to be
|
|
introduced into the global scope that will be used to resolve
|
|
references from other dynamically-loaded objects.
|
|
|
|
The global scope is the searchlist in the main link map. We
|
|
extend this list if necessary. There is one problem though:
|
|
since this structure was allocated very early (before the libc
|
|
is loaded) the memory it uses is allocated by the malloc()-stub
|
|
in the ld.so. When we come here these functions are not used
|
|
anymore. Instead the malloc() implementation of the libc is
|
|
used. But this means the block from the main map cannot be used
|
|
in an realloc() call. Therefore we allocate a completely new
|
|
array the first time we have to add something to the locale scope. */
|
|
|
|
if (__builtin_add_overflow (ns->_ns_global_scope_pending_adds, to_add,
|
|
&ns->_ns_global_scope_pending_adds))
|
|
add_to_global_resize_failure (new);
|
|
|
|
unsigned int new_size = 0; /* 0 means no new allocation. */
|
|
void *old_global = NULL; /* Old allocation if free-able. */
|
|
|
|
/* Minimum required element count for resizing. Adjusted below for
|
|
an exponential resizing policy. */
|
|
size_t required_new_size;
|
|
if (__builtin_add_overflow (ns->_ns_main_searchlist->r_nlist,
|
|
ns->_ns_global_scope_pending_adds,
|
|
&required_new_size))
|
|
add_to_global_resize_failure (new);
|
|
|
|
if (ns->_ns_global_scope_alloc == 0)
|
|
{
|
|
if (__builtin_add_overflow (required_new_size, 8, &new_size))
|
|
add_to_global_resize_failure (new);
|
|
}
|
|
else if (required_new_size > ns->_ns_global_scope_alloc)
|
|
{
|
|
if (__builtin_mul_overflow (required_new_size, 2, &new_size))
|
|
add_to_global_resize_failure (new);
|
|
|
|
/* The old array was allocated with our malloc, not the minimal
|
|
malloc. */
|
|
old_global = ns->_ns_main_searchlist->r_list;
|
|
}
|
|
|
|
if (new_size > 0)
|
|
{
|
|
size_t allocation_size;
|
|
if (__builtin_mul_overflow (new_size, sizeof (struct link_map *),
|
|
&allocation_size))
|
|
add_to_global_resize_failure (new);
|
|
struct link_map **new_global = malloc (allocation_size);
|
|
if (new_global == NULL)
|
|
add_to_global_resize_failure (new);
|
|
|
|
/* Copy over the old entries. */
|
|
memcpy (new_global, ns->_ns_main_searchlist->r_list,
|
|
ns->_ns_main_searchlist->r_nlist * sizeof (struct link_map *));
|
|
|
|
ns->_ns_global_scope_alloc = new_size;
|
|
ns->_ns_main_searchlist->r_list = new_global;
|
|
|
|
if (!RTLD_SINGLE_THREAD_P)
|
|
THREAD_GSCOPE_WAIT ();
|
|
|
|
free (old_global);
|
|
}
|
|
}
|
|
|
|
/* Actually add the new global objects to the global scope. Must be
|
|
called after add_to_global_resize. This function cannot fail. */
|
|
static void
|
|
add_to_global_update (struct link_map *new)
|
|
{
|
|
struct link_namespaces *ns = &GL (dl_ns)[new->l_ns];
|
|
|
|
/* Now add the new entries. */
|
|
unsigned int new_nlist = ns->_ns_main_searchlist->r_nlist;
|
|
for (unsigned int cnt = 0; cnt < new->l_searchlist.r_nlist; ++cnt)
|
|
{
|
|
struct link_map *map = new->l_searchlist.r_list[cnt];
|
|
|
|
if (map->l_global == 0)
|
|
{
|
|
map->l_global = 1;
|
|
|
|
/* The array has been resized by add_to_global_resize. */
|
|
assert (new_nlist < ns->_ns_global_scope_alloc);
|
|
|
|
ns->_ns_main_searchlist->r_list[new_nlist++] = map;
|
|
|
|
/* We modify the global scope. Report this. */
|
|
if (__glibc_unlikely (GLRO(dl_debug_mask) & DL_DEBUG_SCOPES))
|
|
_dl_debug_printf ("\nadd %s [%lu] to global scope\n",
|
|
map->l_name, map->l_ns);
|
|
}
|
|
}
|
|
|
|
/* Some of the pending adds have been performed by the loop above.
|
|
Adjust the counter accordingly. */
|
|
unsigned int added = new_nlist - ns->_ns_main_searchlist->r_nlist;
|
|
assert (added <= ns->_ns_global_scope_pending_adds);
|
|
ns->_ns_global_scope_pending_adds -= added;
|
|
|
|
atomic_write_barrier ();
|
|
ns->_ns_main_searchlist->r_nlist = new_nlist;
|
|
}
|
|
|
|
/* Search link maps in all namespaces for the DSO that contains the object at
|
|
address ADDR. Returns the pointer to the link map of the matching DSO, or
|
|
NULL if a match is not found. */
|
|
struct link_map *
|
|
_dl_find_dso_for_object (const ElfW(Addr) addr)
|
|
{
|
|
struct link_map *l;
|
|
|
|
/* Find the highest-addressed object that ADDR is not below. */
|
|
for (Lmid_t ns = 0; ns < GL(dl_nns); ++ns)
|
|
for (l = GL(dl_ns)[ns]._ns_loaded; l != NULL; l = l->l_next)
|
|
if (addr >= l->l_map_start && addr < l->l_map_end
|
|
&& (l->l_contiguous
|
|
|| _dl_addr_inside_object (l, (ElfW(Addr)) addr)))
|
|
{
|
|
assert (ns == l->l_ns);
|
|
return l;
|
|
}
|
|
return NULL;
|
|
}
|
|
rtld_hidden_def (_dl_find_dso_for_object);
|
|
|
|
/* Return true if NEW is found in the scope for MAP. */
|
|
static size_t
|
|
scope_has_map (struct link_map *map, struct link_map *new)
|
|
{
|
|
size_t cnt;
|
|
for (cnt = 0; map->l_scope[cnt] != NULL; ++cnt)
|
|
if (map->l_scope[cnt] == &new->l_searchlist)
|
|
return true;
|
|
return false;
|
|
}
|
|
|
|
/* Return the length of the scope for MAP. */
|
|
static size_t
|
|
scope_size (struct link_map *map)
|
|
{
|
|
size_t cnt;
|
|
for (cnt = 0; map->l_scope[cnt] != NULL; )
|
|
++cnt;
|
|
return cnt;
|
|
}
|
|
|
|
/* Resize the scopes of depended-upon objects, so that the new object
|
|
can be added later without further allocation of memory. This
|
|
function can raise an exceptions due to malloc failure. */
|
|
static void
|
|
resize_scopes (struct link_map *new)
|
|
{
|
|
/* If the file is not loaded now as a dependency, add the search
|
|
list of the newly loaded object to the scope. */
|
|
for (unsigned int i = 0; i < new->l_searchlist.r_nlist; ++i)
|
|
{
|
|
struct link_map *imap = new->l_searchlist.r_list[i];
|
|
|
|
/* If the initializer has been called already, the object has
|
|
not been loaded here and now. */
|
|
if (imap->l_init_called && imap->l_type == lt_loaded)
|
|
{
|
|
if (scope_has_map (imap, new))
|
|
/* Avoid duplicates. */
|
|
continue;
|
|
|
|
size_t cnt = scope_size (imap);
|
|
if (__glibc_unlikely (cnt + 1 >= imap->l_scope_max))
|
|
{
|
|
/* The l_scope array is too small. Allocate a new one
|
|
dynamically. */
|
|
size_t new_size;
|
|
struct r_scope_elem **newp;
|
|
|
|
if (imap->l_scope != imap->l_scope_mem
|
|
&& imap->l_scope_max < array_length (imap->l_scope_mem))
|
|
{
|
|
/* If the current l_scope memory is not pointing to
|
|
the static memory in the structure, but the
|
|
static memory in the structure is large enough to
|
|
use for cnt + 1 scope entries, then switch to
|
|
using the static memory. */
|
|
new_size = array_length (imap->l_scope_mem);
|
|
newp = imap->l_scope_mem;
|
|
}
|
|
else
|
|
{
|
|
new_size = imap->l_scope_max * 2;
|
|
newp = (struct r_scope_elem **)
|
|
malloc (new_size * sizeof (struct r_scope_elem *));
|
|
if (newp == NULL)
|
|
_dl_signal_error (ENOMEM, "dlopen", NULL,
|
|
N_("cannot create scope list"));
|
|
}
|
|
|
|
/* Copy the array and the terminating NULL. */
|
|
memcpy (newp, imap->l_scope,
|
|
(cnt + 1) * sizeof (imap->l_scope[0]));
|
|
struct r_scope_elem **old = imap->l_scope;
|
|
|
|
imap->l_scope = newp;
|
|
|
|
if (old != imap->l_scope_mem)
|
|
_dl_scope_free (old);
|
|
|
|
imap->l_scope_max = new_size;
|
|
}
|
|
}
|
|
}
|
|
}
|
|
|
|
/* Second stage of resize_scopes: Add NEW to the scopes. Also print
|
|
debugging information about scopes if requested.
|
|
|
|
This function cannot raise an exception because all required memory
|
|
has been allocated by a previous call to resize_scopes. */
|
|
static void
|
|
update_scopes (struct link_map *new)
|
|
{
|
|
for (unsigned int i = 0; i < new->l_searchlist.r_nlist; ++i)
|
|
{
|
|
struct link_map *imap = new->l_searchlist.r_list[i];
|
|
int from_scope = 0;
|
|
|
|
if (imap->l_init_called && imap->l_type == lt_loaded)
|
|
{
|
|
if (scope_has_map (imap, new))
|
|
/* Avoid duplicates. */
|
|
continue;
|
|
|
|
size_t cnt = scope_size (imap);
|
|
/* Assert that resize_scopes has sufficiently enlarged the
|
|
array. */
|
|
assert (cnt + 1 < imap->l_scope_max);
|
|
|
|
/* First terminate the extended list. Otherwise a thread
|
|
might use the new last element and then use the garbage
|
|
at offset IDX+1. */
|
|
imap->l_scope[cnt + 1] = NULL;
|
|
atomic_write_barrier ();
|
|
imap->l_scope[cnt] = &new->l_searchlist;
|
|
|
|
from_scope = cnt;
|
|
}
|
|
|
|
/* Print scope information. */
|
|
if (__glibc_unlikely (GLRO(dl_debug_mask) & DL_DEBUG_SCOPES))
|
|
_dl_show_scope (imap, from_scope);
|
|
}
|
|
}
|
|
|
|
/* Call _dl_add_to_slotinfo with DO_ADD set to false, to allocate
|
|
space in GL (dl_tls_dtv_slotinfo_list). This can raise an
|
|
exception. The return value is true if any of the new objects use
|
|
TLS. */
|
|
static bool
|
|
resize_tls_slotinfo (struct link_map *new)
|
|
{
|
|
bool any_tls = false;
|
|
for (unsigned int i = 0; i < new->l_searchlist.r_nlist; ++i)
|
|
{
|
|
struct link_map *imap = new->l_searchlist.r_list[i];
|
|
|
|
/* Only add TLS memory if this object is loaded now and
|
|
therefore is not yet initialized. */
|
|
if (! imap->l_init_called && imap->l_tls_blocksize > 0)
|
|
{
|
|
_dl_add_to_slotinfo (imap, false);
|
|
any_tls = true;
|
|
}
|
|
}
|
|
return any_tls;
|
|
}
|
|
|
|
/* Second stage of TLS update, after resize_tls_slotinfo. This
|
|
function does not raise any exception. It should only be called if
|
|
resize_tls_slotinfo returned true. */
|
|
static void
|
|
update_tls_slotinfo (struct link_map *new)
|
|
{
|
|
unsigned int first_static_tls = new->l_searchlist.r_nlist;
|
|
for (unsigned int i = 0; i < new->l_searchlist.r_nlist; ++i)
|
|
{
|
|
struct link_map *imap = new->l_searchlist.r_list[i];
|
|
|
|
/* Only add TLS memory if this object is loaded now and
|
|
therefore is not yet initialized. */
|
|
if (! imap->l_init_called && imap->l_tls_blocksize > 0)
|
|
{
|
|
_dl_add_to_slotinfo (imap, true);
|
|
|
|
if (imap->l_need_tls_init
|
|
&& first_static_tls == new->l_searchlist.r_nlist)
|
|
first_static_tls = i;
|
|
}
|
|
}
|
|
|
|
size_t newgen = GL(dl_tls_generation) + 1;
|
|
if (__glibc_unlikely (newgen == 0))
|
|
_dl_fatal_printf (N_("\
|
|
TLS generation counter wrapped! Please report this."));
|
|
/* Can be read concurrently. */
|
|
atomic_store_relaxed (&GL(dl_tls_generation), newgen);
|
|
|
|
/* We need a second pass for static tls data, because
|
|
_dl_update_slotinfo must not be run while calls to
|
|
_dl_add_to_slotinfo are still pending. */
|
|
for (unsigned int i = first_static_tls; i < new->l_searchlist.r_nlist; ++i)
|
|
{
|
|
struct link_map *imap = new->l_searchlist.r_list[i];
|
|
|
|
if (imap->l_need_tls_init
|
|
&& ! imap->l_init_called
|
|
&& imap->l_tls_blocksize > 0)
|
|
{
|
|
/* For static TLS we have to allocate the memory here and
|
|
now, but we can delay updating the DTV. */
|
|
imap->l_need_tls_init = 0;
|
|
#ifdef SHARED
|
|
/* Update the slot information data for at least the
|
|
generation of the DSO we are allocating data for. */
|
|
|
|
/* FIXME: This can terminate the process on memory
|
|
allocation failure. It is not possible to raise
|
|
exceptions from this context; to fix this bug,
|
|
_dl_update_slotinfo would have to be split into two
|
|
operations, similar to resize_scopes and update_scopes
|
|
above. This is related to bug 16134. */
|
|
_dl_update_slotinfo (imap->l_tls_modid);
|
|
#endif
|
|
|
|
dl_init_static_tls (imap);
|
|
assert (imap->l_need_tls_init == 0);
|
|
}
|
|
}
|
|
}
|
|
|
|
/* Mark the objects as NODELETE if required. This is delayed until
|
|
after dlopen failure is not possible, so that _dl_close can clean
|
|
up objects if necessary. */
|
|
static void
|
|
activate_nodelete (struct link_map *new)
|
|
{
|
|
/* It is necessary to traverse the entire namespace. References to
|
|
objects in the global scope and unique symbol bindings can force
|
|
NODELETE status for objects outside the local scope. */
|
|
for (struct link_map *l = GL (dl_ns)[new->l_ns]._ns_loaded; l != NULL;
|
|
l = l->l_next)
|
|
if (l->l_nodelete_pending)
|
|
{
|
|
if (__glibc_unlikely (GLRO (dl_debug_mask) & DL_DEBUG_FILES))
|
|
_dl_debug_printf ("activating NODELETE for %s [%lu]\n",
|
|
l->l_name, l->l_ns);
|
|
|
|
/* The flag can already be true at this point, e.g. a signal
|
|
handler may have triggered lazy binding and set NODELETE
|
|
status immediately. */
|
|
l->l_nodelete_active = true;
|
|
|
|
/* This is just a debugging aid, to indicate that
|
|
activate_nodelete has run for this map. */
|
|
l->l_nodelete_pending = false;
|
|
}
|
|
}
|
|
|
|
/* struct dl_init_args and call_dl_init are used to call _dl_init with
|
|
exception handling disabled. */
|
|
struct dl_init_args
|
|
{
|
|
struct link_map *new;
|
|
int argc;
|
|
char **argv;
|
|
char **env;
|
|
};
|
|
|
|
static void
|
|
call_dl_init (void *closure)
|
|
{
|
|
struct dl_init_args *args = closure;
|
|
_dl_init (args->new, args->argc, args->argv, args->env);
|
|
}
|
|
|
|
static void
|
|
dl_open_worker_begin (void *a)
|
|
{
|
|
struct dl_open_args *args = a;
|
|
const char *file = args->file;
|
|
int mode = args->mode;
|
|
struct link_map *call_map = NULL;
|
|
|
|
/* Determine the caller's map if necessary. This is needed in case
|
|
we have a DST, when we don't know the namespace ID we have to put
|
|
the new object in, or when the file name has no path in which
|
|
case we need to look along the RUNPATH/RPATH of the caller. */
|
|
const char *dst = strchr (file, '$');
|
|
if (dst != NULL || args->nsid == __LM_ID_CALLER
|
|
|| strchr (file, '/') == NULL)
|
|
{
|
|
const void *caller_dlopen = args->caller_dlopen;
|
|
|
|
/* We have to find out from which object the caller is calling.
|
|
By default we assume this is the main application. */
|
|
call_map = GL(dl_ns)[LM_ID_BASE]._ns_loaded;
|
|
|
|
struct link_map *l = _dl_find_dso_for_object ((ElfW(Addr)) caller_dlopen);
|
|
|
|
if (l)
|
|
call_map = l;
|
|
|
|
if (args->nsid == __LM_ID_CALLER)
|
|
args->nsid = call_map->l_ns;
|
|
}
|
|
|
|
/* The namespace ID is now known. Keep track of whether libc.so was
|
|
already loaded, to determine whether it is necessary to call the
|
|
early initialization routine (or clear libc_map on error). */
|
|
args->libc_already_loaded = GL(dl_ns)[args->nsid].libc_map != NULL;
|
|
|
|
/* Retain the old value, so that it can be restored. */
|
|
args->original_global_scope_pending_adds
|
|
= GL (dl_ns)[args->nsid]._ns_global_scope_pending_adds;
|
|
|
|
/* One might be tempted to assert that we are RT_CONSISTENT at this point, but that
|
|
may not be true if this is a recursive call to dlopen. */
|
|
_dl_debug_initialize (0, args->nsid);
|
|
|
|
/* Load the named object. */
|
|
struct link_map *new;
|
|
args->map = new = _dl_map_object (call_map, file, lt_loaded, 0,
|
|
mode | __RTLD_CALLMAP, args->nsid);
|
|
|
|
/* If the pointer returned is NULL this means the RTLD_NOLOAD flag is
|
|
set and the object is not already loaded. */
|
|
if (new == NULL)
|
|
{
|
|
assert (mode & RTLD_NOLOAD);
|
|
return;
|
|
}
|
|
|
|
if (__glibc_unlikely (mode & __RTLD_SPROF))
|
|
/* This happens only if we load a DSO for 'sprof'. */
|
|
return;
|
|
|
|
/* This object is directly loaded. */
|
|
++new->l_direct_opencount;
|
|
|
|
/* It was already open. */
|
|
if (__glibc_unlikely (new->l_searchlist.r_list != NULL))
|
|
{
|
|
/* Let the user know about the opencount. */
|
|
if (__glibc_unlikely (GLRO(dl_debug_mask) & DL_DEBUG_FILES))
|
|
_dl_debug_printf ("opening file=%s [%lu]; direct_opencount=%u\n\n",
|
|
new->l_name, new->l_ns, new->l_direct_opencount);
|
|
|
|
/* If the user requested the object to be in the global
|
|
namespace but it is not so far, prepare to add it now. This
|
|
can raise an exception to do a malloc failure. */
|
|
if ((mode & RTLD_GLOBAL) && new->l_global == 0)
|
|
add_to_global_resize (new);
|
|
|
|
/* Mark the object as not deletable if the RTLD_NODELETE flags
|
|
was passed. */
|
|
if (__glibc_unlikely (mode & RTLD_NODELETE))
|
|
{
|
|
if (__glibc_unlikely (GLRO (dl_debug_mask) & DL_DEBUG_FILES)
|
|
&& !new->l_nodelete_active)
|
|
_dl_debug_printf ("marking %s [%lu] as NODELETE\n",
|
|
new->l_name, new->l_ns);
|
|
new->l_nodelete_active = true;
|
|
}
|
|
|
|
/* Finalize the addition to the global scope. */
|
|
if ((mode & RTLD_GLOBAL) && new->l_global == 0)
|
|
add_to_global_update (new);
|
|
|
|
assert (_dl_debug_initialize (0, args->nsid)->r_state == RT_CONSISTENT);
|
|
|
|
return;
|
|
}
|
|
|
|
/* Schedule NODELETE marking for the directly loaded object if
|
|
requested. */
|
|
if (__glibc_unlikely (mode & RTLD_NODELETE))
|
|
new->l_nodelete_pending = true;
|
|
|
|
/* Load that object's dependencies. */
|
|
_dl_map_object_deps (new, NULL, 0, 0,
|
|
mode & (__RTLD_DLOPEN | RTLD_DEEPBIND | __RTLD_AUDIT));
|
|
|
|
/* So far, so good. Now check the versions. */
|
|
for (unsigned int i = 0; i < new->l_searchlist.r_nlist; ++i)
|
|
if (new->l_searchlist.r_list[i]->l_real->l_versions == NULL)
|
|
{
|
|
struct link_map *map = new->l_searchlist.r_list[i]->l_real;
|
|
_dl_check_map_versions (map, 0, 0);
|
|
#ifndef SHARED
|
|
/* During static dlopen, check if ld.so has been loaded.
|
|
Perform partial initialization in this case. This must
|
|
come after the symbol versioning initialization in
|
|
_dl_check_map_versions. */
|
|
if (map->l_info[DT_SONAME] != NULL
|
|
&& strcmp (((const char *) D_PTR (map, l_info[DT_STRTAB])
|
|
+ map->l_info[DT_SONAME]->d_un.d_val), LD_SO) == 0)
|
|
__rtld_static_init (map);
|
|
#endif
|
|
}
|
|
|
|
#ifdef SHARED
|
|
/* Auditing checkpoint: we have added all objects. */
|
|
if (__glibc_unlikely (GLRO(dl_naudit) > 0))
|
|
{
|
|
struct link_map *head = GL(dl_ns)[new->l_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)
|
|
{
|
|
struct auditstate *state = link_map_audit_state (head, cnt);
|
|
afct->activity (&state->cookie, LA_ACT_CONSISTENT);
|
|
}
|
|
|
|
afct = afct->next;
|
|
}
|
|
}
|
|
}
|
|
#endif
|
|
|
|
/* Notify the debugger all new objects are now ready to go. */
|
|
struct r_debug *r = _dl_debug_initialize (0, args->nsid);
|
|
r->r_state = RT_CONSISTENT;
|
|
_dl_debug_state ();
|
|
LIBC_PROBE (map_complete, 3, args->nsid, r, new);
|
|
|
|
_dl_open_check (new);
|
|
|
|
/* Print scope information. */
|
|
if (__glibc_unlikely (GLRO(dl_debug_mask) & DL_DEBUG_SCOPES))
|
|
_dl_show_scope (new, 0);
|
|
|
|
/* Only do lazy relocation if `LD_BIND_NOW' is not set. */
|
|
int reloc_mode = mode & __RTLD_AUDIT;
|
|
if (GLRO(dl_lazy))
|
|
reloc_mode |= mode & RTLD_LAZY;
|
|
|
|
/* Objects must be sorted by dependency for the relocation process.
|
|
This allows IFUNC relocations to work and it also means copy
|
|
relocation of dependencies are if necessary overwritten.
|
|
__dl_map_object_deps has already sorted l_initfini for us. */
|
|
unsigned int first = UINT_MAX;
|
|
unsigned int last = 0;
|
|
unsigned int j = 0;
|
|
struct link_map *l = new->l_initfini[0];
|
|
do
|
|
{
|
|
if (! l->l_real->l_relocated)
|
|
{
|
|
if (first == UINT_MAX)
|
|
first = j;
|
|
last = j + 1;
|
|
}
|
|
l = new->l_initfini[++j];
|
|
}
|
|
while (l != NULL);
|
|
|
|
int relocation_in_progress = 0;
|
|
|
|
/* Perform relocation. This can trigger lazy binding in IFUNC
|
|
resolvers. For NODELETE mappings, these dependencies are not
|
|
recorded because the flag has not been applied to the newly
|
|
loaded objects. This means that upon dlopen failure, these
|
|
NODELETE objects can be unloaded despite existing references to
|
|
them. However, such relocation dependencies in IFUNC resolvers
|
|
are undefined anyway, so this is not a problem. */
|
|
|
|
for (unsigned int i = last; i-- > first; )
|
|
{
|
|
l = new->l_initfini[i];
|
|
|
|
if (l->l_real->l_relocated)
|
|
continue;
|
|
|
|
if (! relocation_in_progress)
|
|
{
|
|
/* Notify the debugger that relocations are about to happen. */
|
|
LIBC_PROBE (reloc_start, 2, args->nsid, r);
|
|
relocation_in_progress = 1;
|
|
}
|
|
|
|
#ifdef SHARED
|
|
if (__glibc_unlikely (GLRO(dl_profile) != NULL))
|
|
{
|
|
/* If this here is the shared object which we want to profile
|
|
make sure the profile is started. We can find out whether
|
|
this is necessary or not by observing the `_dl_profile_map'
|
|
variable. If it was NULL but is not NULL afterwards we must
|
|
start the profiling. */
|
|
struct link_map *old_profile_map = GL(dl_profile_map);
|
|
|
|
_dl_relocate_object (l, l->l_scope, reloc_mode | RTLD_LAZY, 1);
|
|
|
|
if (old_profile_map == NULL && GL(dl_profile_map) != NULL)
|
|
{
|
|
/* We must prepare the profiling. */
|
|
_dl_start_profile ();
|
|
|
|
/* Prevent unloading the object. */
|
|
GL(dl_profile_map)->l_nodelete_active = true;
|
|
}
|
|
}
|
|
else
|
|
#endif
|
|
_dl_relocate_object (l, l->l_scope, reloc_mode, 0);
|
|
}
|
|
|
|
/* This only performs the memory allocations. The actual update of
|
|
the scopes happens below, after failure is impossible. */
|
|
resize_scopes (new);
|
|
|
|
/* Increase the size of the GL (dl_tls_dtv_slotinfo_list) data
|
|
structure. */
|
|
bool any_tls = resize_tls_slotinfo (new);
|
|
|
|
/* Perform the necessary allocations for adding new global objects
|
|
to the global scope below. */
|
|
if (mode & RTLD_GLOBAL)
|
|
add_to_global_resize (new);
|
|
|
|
/* Demarcation point: After this, no recoverable errors are allowed.
|
|
All memory allocations for new objects must have happened
|
|
before. */
|
|
|
|
/* Finalize the NODELETE status first. This comes before
|
|
update_scopes, so that lazy binding will not see pending NODELETE
|
|
state for newly loaded objects. There is a compiler barrier in
|
|
update_scopes which ensures that the changes from
|
|
activate_nodelete are visible before new objects show up in the
|
|
local scope. */
|
|
activate_nodelete (new);
|
|
|
|
/* Second stage after resize_scopes: Actually perform the scope
|
|
update. After this, dlsym and lazy binding can bind to new
|
|
objects. */
|
|
update_scopes (new);
|
|
|
|
/* FIXME: It is unclear whether the order here is correct.
|
|
Shouldn't new objects be made available for binding (and thus
|
|
execution) only after there TLS data has been set up fully?
|
|
Fixing bug 16134 will likely make this distinction less
|
|
important. */
|
|
|
|
/* Second stage after resize_tls_slotinfo: Update the slotinfo data
|
|
structures. */
|
|
if (any_tls)
|
|
/* FIXME: This calls _dl_update_slotinfo, which aborts the process
|
|
on memory allocation failure. See bug 16134. */
|
|
update_tls_slotinfo (new);
|
|
|
|
/* Notify the debugger all new objects have been relocated. */
|
|
if (relocation_in_progress)
|
|
LIBC_PROBE (reloc_complete, 3, args->nsid, r, new);
|
|
|
|
/* If libc.so was not there before, attempt to call its early
|
|
initialization routine. Indicate to the initialization routine
|
|
whether the libc being initialized is the one in the base
|
|
namespace. */
|
|
if (!args->libc_already_loaded)
|
|
{
|
|
/* dlopen cannot be used to load an initial libc by design. */
|
|
struct link_map *libc_map = GL(dl_ns)[args->nsid].libc_map;
|
|
_dl_call_libc_early_init (libc_map, false);
|
|
}
|
|
|
|
args->worker_continue = true;
|
|
}
|
|
|
|
static void
|
|
dl_open_worker (void *a)
|
|
{
|
|
struct dl_open_args *args = a;
|
|
|
|
args->worker_continue = false;
|
|
|
|
{
|
|
/* Protects global and module specific TLS state. */
|
|
__rtld_lock_lock_recursive (GL(dl_load_tls_lock));
|
|
|
|
struct dl_exception ex;
|
|
int err = _dl_catch_exception (&ex, dl_open_worker_begin, args);
|
|
|
|
__rtld_lock_unlock_recursive (GL(dl_load_tls_lock));
|
|
|
|
if (__glibc_unlikely (ex.errstring != NULL))
|
|
/* Reraise the error. */
|
|
_dl_signal_exception (err, &ex, NULL);
|
|
}
|
|
|
|
if (!args->worker_continue)
|
|
return;
|
|
|
|
int mode = args->mode;
|
|
struct link_map *new = args->map;
|
|
|
|
/* Run the initializer functions of new objects. Temporarily
|
|
disable the exception handler, so that lazy binding failures are
|
|
fatal. */
|
|
{
|
|
struct dl_init_args init_args =
|
|
{
|
|
.new = new,
|
|
.argc = args->argc,
|
|
.argv = args->argv,
|
|
.env = args->env
|
|
};
|
|
_dl_catch_exception (NULL, call_dl_init, &init_args);
|
|
}
|
|
|
|
/* Now we can make the new map available in the global scope. */
|
|
if (mode & RTLD_GLOBAL)
|
|
add_to_global_update (new);
|
|
|
|
/* Let the user know about the opencount. */
|
|
if (__glibc_unlikely (GLRO(dl_debug_mask) & DL_DEBUG_FILES))
|
|
_dl_debug_printf ("opening file=%s [%lu]; direct_opencount=%u\n\n",
|
|
new->l_name, new->l_ns, new->l_direct_opencount);
|
|
}
|
|
|
|
void *
|
|
_dl_open (const char *file, int mode, const void *caller_dlopen, Lmid_t nsid,
|
|
int argc, char *argv[], char *env[])
|
|
{
|
|
if ((mode & RTLD_BINDING_MASK) == 0)
|
|
/* One of the flags must be set. */
|
|
_dl_signal_error (EINVAL, file, NULL, N_("invalid mode for dlopen()"));
|
|
|
|
/* Make sure we are alone. */
|
|
__rtld_lock_lock_recursive (GL(dl_load_lock));
|
|
|
|
if (__glibc_unlikely (nsid == LM_ID_NEWLM))
|
|
{
|
|
/* Find a new namespace. */
|
|
for (nsid = 1; DL_NNS > 1 && nsid < GL(dl_nns); ++nsid)
|
|
if (GL(dl_ns)[nsid]._ns_loaded == NULL)
|
|
break;
|
|
|
|
if (__glibc_unlikely (nsid == DL_NNS))
|
|
{
|
|
/* No more namespace available. */
|
|
__rtld_lock_unlock_recursive (GL(dl_load_lock));
|
|
|
|
_dl_signal_error (EINVAL, file, NULL, N_("\
|
|
no more namespaces available for dlmopen()"));
|
|
}
|
|
else if (nsid == GL(dl_nns))
|
|
{
|
|
__rtld_lock_initialize (GL(dl_ns)[nsid]._ns_unique_sym_table.lock);
|
|
++GL(dl_nns);
|
|
}
|
|
|
|
_dl_debug_initialize (0, nsid)->r_state = RT_CONSISTENT;
|
|
}
|
|
/* Never allow loading a DSO in a namespace which is empty. Such
|
|
direct placements is only causing problems. Also don't allow
|
|
loading into a namespace used for auditing. */
|
|
else if (__glibc_unlikely (nsid != LM_ID_BASE && nsid != __LM_ID_CALLER)
|
|
&& (__glibc_unlikely (nsid < 0 || nsid >= GL(dl_nns))
|
|
/* This prevents the [NSID] index expressions from being
|
|
evaluated, so the compiler won't think that we are
|
|
accessing an invalid index here in the !SHARED case where
|
|
DL_NNS is 1 and so any NSID != 0 is invalid. */
|
|
|| DL_NNS == 1
|
|
|| GL(dl_ns)[nsid]._ns_nloaded == 0
|
|
|| GL(dl_ns)[nsid]._ns_loaded->l_auditing))
|
|
_dl_signal_error (EINVAL, file, NULL,
|
|
N_("invalid target namespace in dlmopen()"));
|
|
|
|
struct dl_open_args args;
|
|
args.file = file;
|
|
args.mode = mode;
|
|
args.caller_dlopen = caller_dlopen;
|
|
args.map = NULL;
|
|
args.nsid = nsid;
|
|
/* args.libc_already_loaded is always assigned by dl_open_worker
|
|
(before any explicit/non-local returns). */
|
|
args.argc = argc;
|
|
args.argv = argv;
|
|
args.env = env;
|
|
|
|
struct dl_exception exception;
|
|
int errcode = _dl_catch_exception (&exception, dl_open_worker, &args);
|
|
|
|
#if defined USE_LDCONFIG && !defined MAP_COPY
|
|
/* We must unmap the cache file. */
|
|
_dl_unload_cache ();
|
|
#endif
|
|
|
|
/* Do this for both the error and success cases. The old value has
|
|
only been determined if the namespace ID was assigned (i.e., it
|
|
is not __LM_ID_CALLER). In the success case, we actually may
|
|
have consumed more pending adds than planned (because the local
|
|
scopes overlap in case of a recursive dlopen, the inner dlopen
|
|
doing some of the globalization work of the outer dlopen), so the
|
|
old pending adds value is larger than absolutely necessary.
|
|
Since it is just a conservative upper bound, this is harmless.
|
|
The top-level dlopen call will restore the field to zero. */
|
|
if (args.nsid >= 0)
|
|
GL (dl_ns)[args.nsid]._ns_global_scope_pending_adds
|
|
= args.original_global_scope_pending_adds;
|
|
|
|
/* See if an error occurred during loading. */
|
|
if (__glibc_unlikely (exception.errstring != NULL))
|
|
{
|
|
/* Avoid keeping around a dangling reference to the libc.so link
|
|
map in case it has been cached in libc_map. */
|
|
if (!args.libc_already_loaded)
|
|
GL(dl_ns)[args.nsid].libc_map = NULL;
|
|
|
|
/* Remove the object from memory. It may be in an inconsistent
|
|
state if relocation failed, for example. */
|
|
if (args.map)
|
|
{
|
|
_dl_close_worker (args.map, true);
|
|
|
|
/* All l_nodelete_pending objects should have been deleted
|
|
at this point, which is why it is not necessary to reset
|
|
the flag here. */
|
|
}
|
|
|
|
assert (_dl_debug_initialize (0, args.nsid)->r_state == RT_CONSISTENT);
|
|
|
|
/* Release the lock. */
|
|
__rtld_lock_unlock_recursive (GL(dl_load_lock));
|
|
|
|
/* Reraise the error. */
|
|
_dl_signal_exception (errcode, &exception, NULL);
|
|
}
|
|
|
|
assert (_dl_debug_initialize (0, args.nsid)->r_state == RT_CONSISTENT);
|
|
|
|
/* Release the lock. */
|
|
__rtld_lock_unlock_recursive (GL(dl_load_lock));
|
|
|
|
return args.map;
|
|
}
|
|
|
|
|
|
void
|
|
_dl_show_scope (struct link_map *l, int from)
|
|
{
|
|
_dl_debug_printf ("object=%s [%lu]\n",
|
|
DSO_FILENAME (l->l_name), l->l_ns);
|
|
if (l->l_scope != NULL)
|
|
for (int scope_cnt = from; l->l_scope[scope_cnt] != NULL; ++scope_cnt)
|
|
{
|
|
_dl_debug_printf (" scope %u:", scope_cnt);
|
|
|
|
for (unsigned int cnt = 0; cnt < l->l_scope[scope_cnt]->r_nlist; ++cnt)
|
|
if (*l->l_scope[scope_cnt]->r_list[cnt]->l_name)
|
|
_dl_debug_printf_c (" %s",
|
|
l->l_scope[scope_cnt]->r_list[cnt]->l_name);
|
|
else
|
|
_dl_debug_printf_c (" %s", RTLD_PROGNAME);
|
|
|
|
_dl_debug_printf_c ("\n");
|
|
}
|
|
else
|
|
_dl_debug_printf (" no scope\n");
|
|
_dl_debug_printf ("\n");
|
|
}
|