The algorithm for scanning dependencies upon dlclose is
less than immediately obvious. This patch adds two bits
of comments that explain why you start the dependency
search at l_initfini[1], and why you need to restart
the search.
---
2013-05-09 Carlos O'Donell <carlos@redhat.com>
* elf/dl-close.c (_dl_close_worker): Add comments.
When unmapping the first object in a namespace, the runtime linker
did not update the externally visible pointer. This resulted in
debuggers seeing pointers to memory that had been freed.
[BZ #13579] Do not free l_initfini and allow it to be reused
on subsequent dl_open calls for the same library. This fixes
the invalid memory access in do_lookup_x when the previously
free'd l_initfini was accessed through l_searchlist when a
library had been opened for the second time.
* elf/dl-close.c (_dl_close): Check for it.
* elf/dl-reloc.c (CHECK_STATIC_TLS): Likewise.
(_dl_allocate_static_tls): Likewise.
* elf/dl-tls.c (_dl_allocate_tls_init): Likewise.
(__tls_get_addr): Protect from race conditions in setting l_tls_offset
to it.
* elf/tst-tls16.c: New file.
* elf/tst-tlsmod16a.c: New file.
* elf/tst-tlsmod16b.c: New file.
* elf/Makefile: Add rules to build and run tst-tls16.
void * pointers instead of struct link_map **.
(_dl_scope_free): Change argument type to void *.
* include/link.h (struct link_map): Change type of l_reldeps
to struct link_map_reldeps, move l_reldepsact into that
struct too.
* elf/dl-deps.c: Include atomic.h.
(_dl_map_object_deps): Only change l->l_initfini when it is
fully populated, use _dl_scope_free for freeing it. Optimize
removal of libs from reldeps by using l_reserved flag, when
some removal is needed, allocate a new list instead of
reallocating and free the old with _dl_scope_free. Adjust
for l_reldeps and l_reldepsact changes.
* elf/dl-lookup.c (add_dependency): Likewise. Reorganize to allow
searching in l_initfini and l_reldeps without holding dl_load_lock.
* elf/dl-fini.c (_dl_sort_fini): Adjust for l_reldeps and
l_reldepsact changes.
* elf/dl-close.c (_dl_close_worker): Likewise.
* elf/dl-open.c (_dl_scope_free): Change argument type to void *.
2007-06-13 Jakub Jelinek <jakub@redhat.com>
* include/link.h: Don't include rtld-lowlevel.h.
(struct link_map): Remove l_scope_lock.
* sysdeps/generic/ldsodefs.h: Don't include rtld-lowlevel.h.
(_dl_scope_free_list): New field (variable) in _rtld_global.
(DL_LOOKUP_SCOPE_LOCK): Remove.
(_dl_scope_free): New prototype.
* elf/dl-runtime.c (_dl_fixup): Don't use __rtld_mrlock_*lock.
Don't pass DL_LOOKUP_SCOPE_LOCK to _dl_lookup_symbol_x.
(_dl_profile_fixup): Likewise.
* elf/dl-sym.c (do_sym): Likewise. Use wrapped _dl_lookup_symbol_x
whenever !RTLD_SINGLE_THREAD_P, use THREAD_GSCOPE_SET_FLAG and
THREAD_GSCOPE_RESET_FLAG around it.
* elf/dl-close.c (_dl_close_worker): Don't use
__rtld_mrlock_{change,done}. Call _dl_scope_free on the old
scope. Make sure THREAD_GSCOPE_WAIT () happens if any old
scopes were queued or if l_scope_mem has been abandoned.
* elf/dl-open.c (_dl_scope_free): New function.
(dl_open_worker): Use it. Don't use __rtld_mrlock_{change,done}.
* elf/dl-support.c (_dl_scope_free_list): New variable.
* elf/dl-lookup.c (add_dependency): Remove flags argument.
Remove DL_LOOKUP_SCOPE_LOCK handling.
(_dl_lookup_symbol_x): Adjust caller. Remove DL_LOOKUP_SCOPE_LOCK
handling.
* elf/dl-object.c (_dl_new_object): Don't use
__rtld_mrlock_initialize.
2007-06-19 Ulrich Drepper <drepper@redhat.com>
global scope, wait for all lookups to finish afterwards.
* elf/dl-open.c (add_to_global): When global scope array must
grow, allocate a new one and free old array only after all
lookups finish.
* elf/dl-runtime.c (_dl_fixup): Protect using global scope.
(_dl_lookup_symbol_x): Likewise.
* elf/dl-support.c: Define _dl_wait_lookup_done.
* sysdeps/generic/ldsodefs.h (struct rtld_global): Add
_dl_wait_lookup_done.
split out locking and parameter checking.
(_dl_close): Call _dl_close_worker after locking and checking.
* elf/dl-open.c (_dl_open): Call _dl_close_worker instead of
_dl_close.
we are sure we do not need it anymore for _dl_close. Also move
* elf/dl-lookup.c (_dl_debug_bindings): Remove unused symbol_scope
argument.
(_dl_lookup_symbol_x): Adjust caller.
* sysdeps/generic/ldsodefs.h (struct link_namespaces): Remove
_ns_global_scope.
* elf/rtld.c (dl_main): Don't initialize _ns_global_scope.
* elf/dl-libc.c: Revert l_scope name changes.
* elf/dl-load.c: Likewise.
* elf/dl-object.c: Likewise.
* elf/rtld.c: Likewise.
* elf/dl-close.c (_dl_close): Likewise.
* elf/dl-open.c (dl_open_worker): Likewise. If not SINGLE_THREAD_P,
always use __rtld_mrlock_{change,done}. Always free old scope list
here if not l_scope_mem.
* elf/dl-runtime.c (_dl_fixup, _dl_profile_fixup): Revert l_scope name
change. Never free scope list here. Just __rtld_mrlock_lock before
the lookup and __rtld_mrlock_unlock it after the lookup.
* elf/dl-sym.c: Likewise.
* include/link.h (struct r_scoperec): Remove.
(struct link_map): Replace l_scoperec with l_scope, l_scoperec_mem
with l_scope_mem and l_scoperec_lock with l_scope_lock.
2006-10-17 Jakub Jelinek <jakub@redhat.com>
* sunrpc/xdr_mem.c (xdrmem_setpos): Don't compare addresses
as signed longs, check for x_base + pos overflow.
* sunrpc/Makefile (tests): Add tst-xdrmem2.
* sunrpc/tst-xdrmem2.c: New test.
2006-10-18 Ulrich Drepper <drepper@redhat.com>
* elf/dl-lookup.c (_dl_lookup_symbol_x): Add warning to
_dl_lookup_symbol_x code.
2006-10-17 Jakub Jelinek <jakub@redhat.com>
* elf/dl-runtime.c: Include sysdep-cancel.h.
(_dl_fixup, _dl_profile_fixup): Use __rtld_mrlock_* and
scoperec->nusers only if !SINGLE_THREAD_P. Use atomic_*
instead of catomic_* macros.
* elf/dl-sym.c: Include sysdep-cancel.h.
(do_sym): Use __rtld_mrlock_* and scoperec->nusers only
if !SINGLE_THREAD_P. Use atomic_* instead of catomic_* macros.
* elf/dl-close.c: Include sysdep-cancel.h.
(_dl_close): Use __rtld_mrlock_* and scoperec->nusers only
if !SINGLE_THREAD_P. Use atomic_* instead of catomic_* macros.
* elf/dl-open.c: Include sysdep-cancel.h.
(dl_open_worker): Use __rtld_mrlock_* and scoperec->nusers only
if !SINGLE_THREAD_P. Use atomic_* instead of catomic_* macros.
2006-10-17 Jakub Jelinek <jakub@redhat.com>
[BZ #3313]
* malloc/malloc.c (malloc_consolidate): Set maxfb to address of last
fastbin rather than end of fastbin array.
2006-10-18 Ulrich Drepper <drepper@redhat.com>
* sysdeps/i386/i486/bits/atomic.h (catomic_decrement): Use correct
body macro.
* sysdeps/x86_64/bits/atomic.h
(__arch_c_compare_and_exchange_val_64_acq): Add missing casts.
(catomic_decrement): Use correct body macro.
2006-10-17 Jakub Jelinek <jakub@redhat.com>
* include/atomic.h: Add a unique prefix to all local variables
in macros.
* csu/tst-atomic.c (do_test): Test also catomic_* macros.
* include/link.h: Include <rtld-lowlevel.h>. Define struct
Implement reference counting of scope records.
* elf/dl-close.c (_dl_close): Remove all scopes from removed objects
from the list in objects which remain. Always allocate new scope
record.
* elf/dl-open.c (dl_open_worker): When growing array for scopes,
don't resize, allocate a new one.
* elf/dl-runtime.c: Update reference counters before using a scope
array.
* elf/dl-sym.c: Likewise.
* elf/dl-libc.c: Adjust for l_scope name change.
* elf/dl-load.c: Likewise.
* elf/dl-object.c: Likewise.
* elf/rtld.c: Likewise.
* include/link.h: Inlcude <rtld-lowlevel.h>. Define struct
r_scoperec. Replace r_scope with pointer to r_scoperec structure.
Add l_scoperec_lock.
* sysdeps/generic/ldsodefs.h: Include <rtld-lowlevel.h>.
* sysdeps/generic/rtld-lowlevel.h: New file.
* include/atomic.h: Rename atomic_and to atomic_and_val and
atomic_or to atomic_or_val. Define new macros atomic_and and
atomic_or which do not return values.
* sysdeps/x86_64/bits/atomic.h: Define atomic_and and atomic_or.
Various cleanups.
* sysdeps/i386/i486/bits/atomic.h: Likewise.
sure no reference to the unloaded map's search list remains in the
dependency's scope.
2006-09-16 Jakub Jelinek <jakub@redhat.com>
* elf/Makefile: Add rules to build and run unload7 test.
* elf/unload7.c: New test.
* elf/unload7mod1.c: New file.
* elf/unload7mod2.c: New file.
(_dl_close): If called recursively, just remember GC needs to be rerun
and decrease l_direct_opencount. Avoid GC if l_direct_opencount
decreased to 1. Rerun GC at the end if any destructor unloaded some
additional libraries.
* elf/Makefile: Add rules to build and run unload6 test.
* elf/unload6.c: New test.
* elf/unload6mod1.c: New file.
* elf/unload6mod2.c: New file.
* elf/unload6mod3.c: New file.
* malloc/hooks.c (mem2chunk_check): Add magic_p argument, set *magic_p
if magic_p is not NULL.
(top_check): Invoke MALLOC_FAILURE_ACTION if MORECORE failed.
(malloc_check): Fail if sz == -1.
(free_check): Adjust mem2chunk_check caller.
(realloc_check): Likewise. Fail if bytes == -1. If bytes == 0 and
oldmem != NULL, call free_check and return NULL. If reallocating
and returning NULL, invert magic byte again to make oldmem valid
region for further checking.
(memalign_check): Fail if bytes == -1.
* malloc/Makefile: Add rules to build and run tst-mcheck.
* malloc/tst-mcheck.c: New test.
function _dl_sort_fini.
(_dl_sort_fini): New function.
* sysdeps/generic/ldsodefs.h: Declare _dl_sort_fini.
* elf/dl-close.c (_dl_close): Call _dl_sort_fini before running
destructors to call them in the right order.
Change type of l_idx to int.
* elf/dl-close.c: Basically rewrite. Do not use l_opencount to
determine whether a DSO has to be unloaded. Instead compute this
in this function.
* elf/dl-deps.c: No need to manipulate l_opencount anymore.
* elf/dl-lookup.c: Likewise.
* elf/rtld.c: Likewise
* elf/dl-open.c: Likewise. Use l_init_called to determine whether
object was just loaded.
* elf/dl-fini.c: Bump l_direct_opencount instead of l_opencount.
* elf/dl-load.c (_dl_map_object_from_fd): Do not recognize DSO which
is about to be unloaded as a match.
(_dl_map_object): Likewise.
* elf/do-lookup.h (do_lookup_x): Do not look into DSO which is about
to be unloaded.
* elf/circleload1.c: Don't use l_opencount anymore.
* elf/neededtest.c: Likewise.
* elf/neededtest2.c: Likewise.
* elf/neededtest3.c: Likewise.
* elf/neededtest4.c: Likewise.
* elf/unload.c: Likewise.
* elf/unload2.c: Likewise.
* elf/loadtest.c: Likewise.
* elf/rtld.c: Preloading errors are now never fatal.
2005-03-08 Jakub Jelinek <jakub@redhat.com>
* elf/Makefile: Add rules to build and run unload5 test.
* elf/unload5.c: New file.
2005-03-08 Jakub Jelinek <jakub@redhat.com>
* elf/Makefile: Add rules to build and run unload4 test.
* elf/unload4.c: New file.
* elf/unload4mod1.c: New file.
* elf/unload4mod2.c: New file.
* elf/unload4mod3.c: New file.
* elf/unload4mod4.c: New file.
2005-03-01 H.J. Lu <hongjiu.lu@intel.com>
[BZ #776]
* iconv/iconvconfig.c: Fix comment for the output file.
(write_output): Clear padding in header.
2005-03-03 Ulrich Drepper <drepper@redhat.com>
* elf/dl-close.c (_dl_close): Don't try to set up new searchpath if the
loader is closed. Fixes unload3.
* elf/tst-global1.c: New file.
* elf/Makefile (tests): Add tst-global1.
2005-03-03 Jakub Jelinek <jakub@redhat.com>
* elf/Makefile: Add rules to build and run unload3 test.
* elf/unload3.c: New test.
* elf/unload3mod1.c: New file.
* elf/unload3mod2.c: New file.
* elf/unload3mod3.c: New file.
* elf/unload3mod4.c: New file.
2005-01-09 Ulrich Drepper <drepper@redhat.com>
* elf/dl-debug.c (_dl_debug_initialize): Take extra parameter and
use it to select the r_debug structure for that namespace.
* elf/dl-close.c (_dl_close): Adjust call to _dl_debug_initialize.
* elf/dl-load.c (_dl_map_object_from_fd): Likewise.
* elf/dl-open.c (_dl_open): Likewise.
* elf/rtld.c (dl_main): Likewise.
* sysdeps/generic/ldsodefs.h (struct link_namespaces): Add _ns_debug
member.
(_dl_debug_initialize): Add new parameter in declaration.
* elf/dl-close.c (_dl_close): Make sure auditing callbacks are not
called for the auditing objects themselves.
* elf/dl-load.c (_dl_map_object_from_fd): Likewise.
2004-10-14 Jakub Jelinek <jakub@redhat.com>
* elf/rtld.c (_dl_start): Fix one last dl_loaded.
* elf/dl-load.c (_dl_map_object_from_fd): Avoid definition of
label when it is not needed.
* elf/dl-close.c (_dl_close): Typo: & -> &&.
Update.
Add support for namespaces in the dynamic linker.
* dlfcn/Makefile (libdl-routines): Add dlmopen.
* dlfcn/Versions [libdl, GLIBC_2.3.4]: Add dlmopen.
* dlfcn/dlfcn.h: Define Lmid_t, LM_ID_BASE, and LM_ID_NEWLM.
Declare dlmopen. Document RTLD_DI_LMID.
* dlfcn/dlinfo.c: Handle RTLD_DI_LMID.
* dlfcn/dlmopen.c: New file.
* dlfcn/dlopen.c: Pass new parameter to _dl_open.
* dlfcn/dlopenold.c: Likewise.
* elf/dl-addr.c: Adjust for removal of GL(dl_loaded).
* elf/dl-caller.c: Likewise.
* elf/dl-close.c: Likewise.
* elf/dl-conflict.c: Likewise.
* elf/dl-debug.c: Likewise.
* elf/dl-lookup.c: Likewise.
* elf/dl-sym.c: Likewise.
* elf/dl-version.c: Likewise.
* elf/do-lookup.h: Likewise.
* elf/rtld.c: Likewise.
* sysdeps/unix/sysv/linux/i386/dl-librecon.h: Likewise.
* elf/dl-depsc: Likewise. Add new parameter to _dl_map_object.
* elf/dl-fini.c: Call destructors in all namespaces.
* elf/dl-iteratephdr.c: Compute total nloaded. Adjust for removal of
GL(dl_loaded).
* elf/dl-libc.c: Pass new parameter to _dl_open. Adjust for removal
of GL(dl_loaded).
* elf/dl-load.c (_dl_map_object_from_fd): Don't load ld.so a second
time. Reuse the one from the main namespace in all others.
Pass new parameter to _dl_new_object.
Adjust for removal of GL(dl_loaded).
* elf/dl-object.c: Take new parameter. Use it to initialize l_ns.
Adjust for removal of GL(dl_loaded).
* elf/dl-open.c (_dl_open): Take new parameter.
Adjust for removal of GL(dl_loaded).
* elf/dl-support.c: Replace global _dl_loaded etc variables with
_dl_ns variable.
* include/dlfcn.h: Adjust prototype of _dl_open.
Define __LM_ID_CALLER.
* include/link.h: Add l_real, l_ns, and l_direct_opencount elements.
* sysdeps/generic/dl-tls.c: Bump TLS_STATIC_SURPLUS. Since libc is
using TLS we need memory appropriate to the number of namespaces.
* sysdeps/generic/ldsodefs.h (struct rtld_global): Replace _dl_loaded,
_dl_nloaded, _dl_global_scope, _dl_main_searchlist, and
_dl_global_scope_alloc with _dl_ns element. Define DL_NNS.
Adjust prototypes of _dl_map_object and member in rtld_global_ro.
* malloc/malloc.c: Include <dlfcn.h>.
* malloc/arena.c (ptmalloc_init): If libc is not in primary namespace,
never use brk.
* elf/Makefile: Add rules to build and run tst-dlmopen1 and
tst-dlmopen2.
* elf/tst-dlmopen1.c: New file.
* elf/tst-dlmopen1mod.c: New file.
* elf/tst-dlmopen2.c: New file.
* elf/dl-close.c: Improve reference counting by tracking direct loads.
* elf/dl-lookup.c (add_dependency): Likewise.
* elf/dl-open.c (dl_open_worker): Likewise.
* elf/rtld.c (dl_main): Likewise.
2004-09-09 GOTO Masanori <gotom@debian.or.jp>
[BZ #77]
* elf/dl-close.c: Count down l_opencount to check not only for
l_reldeps, but also l_initfini.
2004-10-13 Ulrich Drepper <drepper@redhat.com>
