* sysdeps/powerpc/powerpc64/multiarch/strnlen-power7.S: Likewise.
* sysdeps/powerpc/powerpc64/multiarch/wcscpy.c: Likewise.
-2014-01-03 Andrew Hunter <ahh@google.com>
-
- * elf/dl-open.c (dl_open_worker): New comment.
- * elf/dl-reloc.c (_dl_try_allocate_static_tls): Use
- atomic_compare_and_exchange_bool_acq
- (_dl_allocate_static_tls): Block signals.
- * elf/dl-tls.c (allocate_and_init): Return void.
- (_dl_update_slotinfo): Block signals, use atomic update.
-
2014-01-03 Joseph Myers <joseph@codesourcery.com>
* sysdeps/powerpc/nofpu/libm-test-ulps: Regenerated.
generation of the DSO we are allocating data for. */
_dl_update_slotinfo (imap->l_tls_modid);
#endif
- /* We do this iteration under a signal mask in dl-reloc; why not
- here? Because these symbols are new and dlopen hasn't
- returned yet. So we can't possibly be racing with a TLS
- access to them from another thread. */
+
GL(dl_init_static_tls) (imap);
assert (imap->l_need_tls_init == 0);
}
License along with the GNU C Library; if not, see
<http://www.gnu.org/licenses/>. */
-#include <atomic.h>
#include <errno.h>
#include <libintl.h>
-#include <signal.h>
#include <stdlib.h>
#include <unistd.h>
#include <ldsodefs.h>
size_t offset = GL(dl_tls_static_used) + (freebytes - n * map->l_tls_align
- map->l_tls_firstbyte_offset);
+
+ map->l_tls_offset = GL(dl_tls_static_used) = offset;
#elif TLS_DTV_AT_TP
/* dl_tls_static_used includes the TCB at the beginning. */
size_t offset = (((GL(dl_tls_static_used)
if (used > GL(dl_tls_static_size))
goto fail;
-#else
-# error "Either TLS_TCB_AT_TP or TLS_DTV_AT_TP must be defined"
-#endif
- /* We've computed the new value we want, now try to install it. */
- ptrdiff_t val;
- if ((val = map->l_tls_offset) == NO_TLS_OFFSET)
- {
- /* l_tls_offset starts out at NO_TLS_OFFSET, and all attempts to
- change it go from NO_TLS_OFFSET to some other value. We use
- compare_and_exchange to ensure only one attempt succeeds. We
- don't actually need any memory ordering here, but _acq is the
- weakest available. */
- (void ) atomic_compare_and_exchange_bool_acq (&map->l_tls_offset,
- offset,
- NO_TLS_OFFSET);
- val = map->l_tls_offset;
- assert (val != NO_TLS_OFFSET);
- }
- if (val != offset)
- {
- /* We'd like to set a static offset for this section, but another
- thread has already used a dynamic TLS block for it. Since we can
- only use static offsets if everyone does (and it's not practical
- to move that thread's dynamic block), we have to fail. */
- goto fail;
- }
- /* We installed the value; now update the globals. */
-#if TLS_TCB_AT_TP
- GL(dl_tls_static_used) = offset;
-#elif TLS_DTV_AT_TP
+ map->l_tls_offset = offset;
map->l_tls_firstbyte_offset = GL(dl_tls_static_used);
GL(dl_tls_static_used) = used;
#else
internal_function __attribute_noinline__
_dl_allocate_static_tls (struct link_map *map)
{
- /* We wrap this in a signal mask because it has to iterate all threads
- (including this one) and update this map's TLS entry. A signal handler
- accessing TLS would try to do the same update and break. */
- sigset_t old;
- _dl_mask_all_signals (&old);
- int err = -1;
- if (map->l_tls_offset != FORCED_DYNAMIC_TLS_OFFSET)
- err = _dl_try_allocate_static_tls (map);
-
- _dl_unmask_signals (&old);
- if (err != 0)
+ if (map->l_tls_offset == FORCED_DYNAMIC_TLS_OFFSET
+ || _dl_try_allocate_static_tls (map))
{
_dl_signal_error (0, map->l_name, NULL, N_("\
cannot allocate memory in static TLS block"));
<http://www.gnu.org/licenses/>. */
#include <assert.h>
-#include <atomic.h>
#include <errno.h>
#include <libintl.h>
#include <signal.h>
# endif
-static void
-allocate_and_init (dtv_t *dtv, struct link_map *map)
+static void *
+allocate_and_init (struct link_map *map)
{
void *newp;
newp = __signal_safe_memalign (map->l_tls_align, map->l_tls_blocksize);
if (newp == NULL)
oom ();
- /* Initialize the memory. Since this is our thread's space, we are
- under a signal mask, and no one has touched this section before,
- we can safely just overwrite whatever's there. */
+ /* Initialize the memory. */
memset (__mempcpy (newp, map->l_tls_initimage, map->l_tls_initimage_size),
'\0', map->l_tls_blocksize - map->l_tls_initimage_size);
- dtv->pointer.val = newp;
+ return newp;
}
the entry we need. */
size_t new_gen = listp->slotinfo[idx].gen;
size_t total = 0;
- sigset_t old;
-
- _dl_mask_all_signals (&old);
- /* We use the signal mask as a lock against reentrancy here.
- Check that a signal taken before the lock didn't already
- update us. */
- dtv = THREAD_DTV ();
- if (dtv[0].counter >= listp->slotinfo[idx].gen)
- goto out;
+
/* We have to look through the entire dtv slotinfo list. */
listp = GL(dl_tls_dtv_slotinfo_list);
do
/* This will be the new maximum generation counter. */
dtv[0].counter = new_gen;
- out:
- _dl_unmask_signals (&old);
}
return the_map;
the_map = listp->slotinfo[idx].map;
}
- sigset_t old;
- _dl_mask_all_signals (&old);
-
- /* As with update_slotinfo, we use the sigmask as a check against
- reentrancy. */
- if (dtv[GET_ADDR_MODULE].pointer.val != TLS_DTV_UNALLOCATED)
- goto out;
-
- /* Synchronize against a parallel dlopen() forcing this variable
- into static storage. If that happens, we have to be more careful
- about initializing the area, as that dlopen() will be iterating
- the threads to do so itself. */
- ptrdiff_t offset;
- if ((offset = the_map->l_tls_offset) == NO_TLS_OFFSET)
- {
- /* l_tls_offset starts out at NO_TLS_OFFSET, and all attempts to
- change it go from NO_TLS_OFFSET to some other value. We use
- compare_and_exchange to ensure only one attempt succeeds. We
- don't actually need any memory ordering here, but _acq is the
- weakest available. */
- (void) atomic_compare_and_exchange_bool_acq (&the_map->l_tls_offset,
- FORCED_DYNAMIC_TLS_OFFSET,
- NO_TLS_OFFSET);
- offset = the_map->l_tls_offset;
- assert (offset != NO_TLS_OFFSET);
- }
- if (offset == FORCED_DYNAMIC_TLS_OFFSET)
- {
- allocate_and_init (&dtv[GET_ADDR_MODULE], the_map);
- }
- else
+
+ again:
+ /* Make sure that, if a dlopen running in parallel forces the
+ variable into static storage, we'll wait until the address in the
+ static TLS block is set up, and use that. If we're undecided
+ yet, make sure we make the decision holding the lock as well. */
+ if (__builtin_expect (the_map->l_tls_offset
+ != FORCED_DYNAMIC_TLS_OFFSET, 0))
{
- void **pp = &dtv[GET_ADDR_MODULE].pointer.val;
- while (atomic_forced_read (*pp) == TLS_DTV_UNALLOCATED)
+ __rtld_lock_lock_recursive (GL(dl_load_lock));
+ if (__builtin_expect (the_map->l_tls_offset == NO_TLS_OFFSET, 1))
{
- /* for lack of a better (safe) thing to do, just spin.
- Someone else (not us; it's done under a signal mask) set
- this map to a static TLS offset, and they'll iterate all
- threads to initialize it. They'll eventually write
- to pointer.val, at which point we know they've fully
- completed initialization. */
- atomic_delay ();
+ the_map->l_tls_offset = FORCED_DYNAMIC_TLS_OFFSET;
+ __rtld_lock_unlock_recursive (GL(dl_load_lock));
+ }
+ else
+ {
+ __rtld_lock_unlock_recursive (GL(dl_load_lock));
+ if (__builtin_expect (the_map->l_tls_offset
+ != FORCED_DYNAMIC_TLS_OFFSET, 1))
+ {
+ void *p = dtv[GET_ADDR_MODULE].pointer.val;
+ if (__builtin_expect (p == TLS_DTV_UNALLOCATED, 0))
+ goto again;
+
+ return (char *) p + GET_ADDR_OFFSET;
+ }
}
- /* Make sure we've picked up their initialization of the actual
- block; this pairs against the write barrier in
- init_one_static_tls, guaranteeing that we see their write of
- the tls_initimage into the static region. */
- atomic_read_barrier ();
}
-out:
- assert (dtv[GET_ADDR_MODULE].pointer.val != TLS_DTV_UNALLOCATED);
- _dl_unmask_signals (&old);
+ void *p = dtv[GET_ADDR_MODULE].pointer.val = allocate_and_init (the_map);
+ dtv[GET_ADDR_MODULE].pointer.is_static = false;
- return (char *) dtv[GET_ADDR_MODULE].pointer.val + GET_ADDR_OFFSET;
+ return (char *) p + GET_ADDR_OFFSET;
}
(do_test): Call it.
* tst-tls7mod.c (action): Move sem_post to caller.
-2014-01-03 Andrew Hunter <ahh@google.com>
-
- * nptl/Makefile (tst-tls7): New test.
- * nptl/tst-tls7.c: New file.
- * nptl/tst-tls7mod.c: New file.
- * nptl/allocatestack.c (init_one_static_tls): Use atomic barrier.
-
-2013-12-12 Adhemerval Zanella <azanella@linux.vnet.ibm.com>
+2011-12-12 Adhemerval Zanella <azanella@linux.vnet.ibm.com>
* sysdeps/powerpc/tls.h (struct tcbhead_t): Add DSO and TAR fields.
* nptl/sysdeps/powerpc/tcb-offsets.sym: Likewise.
tst-oncex3 tst-oncex4
endif
ifeq ($(build-shared),yes)
-tests += tst-atfork2 tst-tls3 tst-tls4 tst-tls5 tst-tls7 tst-_res1 tst-fini1 \
+tests += tst-atfork2 tst-tls3 tst-tls4 tst-tls5 tst-_res1 tst-fini1 \
tst-stackguard1
tests-nolibpthread += tst-fini1
ifeq ($(have-z-execstack),yes)
modules-names = tst-atfork2mod tst-tls3mod tst-tls4moda tst-tls4modb \
tst-tls5mod tst-tls5moda tst-tls5modb tst-tls5modc \
tst-tls5modd tst-tls5mode tst-tls5modf \
- tst-_res1mod1 tst-_res1mod2 tst-execstack-mod tst-fini1mod \
- tst-tls7mod
+ tst-_res1mod1 tst-_res1mod2 tst-execstack-mod tst-fini1mod
extra-test-objs += $(addsuffix .os,$(strip $(modules-names))) tst-cleanup4aux.o
test-extras += $(modules-names) tst-cleanup4aux
test-modules = $(addprefix $(objpfx),$(addsuffix .so,$(modules-names)))
tst-tls5modd.so-no-z-defs = yes
tst-tls5mode.so-no-z-defs = yes
tst-tls5modf.so-no-z-defs = yes
-tst-tls7mod.so-no-z-defs = yes
ifeq ($(build-shared),yes)
# Build all the modules even when not actually running test programs.
LDFLAGS-tst-tls5 = $(no-as-needed)
LDFLAGS-tst-tls5mod.so = -Wl,-soname,tst-tls5mod.so
-# ensure free(malloc()) isn't optimized out
-CFLAGS-tst-tls7.c = -fno-builtin-malloc -fno-builtin-free
-$(objpfx)tst-tls7: $(libdl) $(shared-thread-library)
-$(objpfx)tst-tls7.out: $(objpfx)tst-tls7mod.so
-$(objpfx)tst-tls7mod.so: $(shared-thread-library)
-
ifeq ($(build-shared),yes)
ifeq ($(run-built-tests),yes)
tests: $(objpfx)tst-tls6.out
# error "Either TLS_TCB_AT_TP or TLS_DTV_AT_TP must be defined"
# endif
- /* Initialize the memory. */
- memset (__mempcpy (dest, map->l_tls_initimage, map->l_tls_initimage_size),
- '\0', map->l_tls_blocksize - map->l_tls_initimage_size);
-
/* Fill in the DTV slot so that a later LD/GD access will find it. */
- dtv[map->l_tls_modid].pointer.is_static = true;
- /* Pairs against the read barrier in tls_get_attr_tail, guaranteeing
- any thread waiting for an update to pointer.val sees the
- initimage write. */
- atomic_write_barrier ();
dtv[map->l_tls_modid].pointer.val = dest;
+ dtv[map->l_tls_modid].pointer.is_static = true;
+ /* Initialize the memory. */
+ memset (__mempcpy (dest, map->l_tls_initimage, map->l_tls_initimage_size),
+ '\0', map->l_tls_blocksize - map->l_tls_initimage_size);
}
void
+++ /dev/null
-/* Copyright (C) 2013 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/>. */
-
-
-/* This test checks that TLS in a dlopened object works when first accessed
- from a signal handler. */
-
-#include <assert.h>
-#include <atomic.h>
-#include <dlfcn.h>
-#include <pthread.h>
-#include <semaphore.h>
-#include <signal.h>
-#include <stdio.h>
-#include <stdlib.h>
-
-void *
-spin (void *ignored)
-{
- while (1)
- {
- /* busywork */
- free (malloc (128));
- }
-
- /* never reached */
- return NULL;
-}
-
-static void (*tls7mod_action) (int, siginfo_t *, void *);
-
-static void
-action (int signo, siginfo_t *info, void *ignored)
-{
- sem_t *sem = info->si_value.sival_ptr;
-
- atomic_read_barrier ();
- assert (tls7mod_action != NULL);
- (*tls7mod_action) (signo, info, ignored);
-
- /* This sem_post may trigger dlclose, which will invalidate tls7mod_action.
- It is important to do that only after tls7mod_action is no longer
- active. */
- sem_post (sem);
-}
-
-int
-do_test (void)
-{
- pthread_t th[10];
-
- for (int i = 0; i < 10; ++i)
- {
- if (pthread_create (&th[i], NULL, spin, NULL))
- {
- puts ("pthread_create failed");
- exit (1);
- }
- }
-#define NITERS 75
-
- for (int i = 0; i < NITERS; ++i)
- {
- void *h = dlopen ("tst-tls7mod.so", RTLD_LAZY);
- if (h == NULL)
- {
- puts ("dlopen failed");
- exit (1);
- }
-
- tls7mod_action = dlsym (h, "action");
- if (tls7mod_action == NULL)
- {
- puts ("dlsym for action failed");
- exit (1);
- }
- atomic_write_barrier ();
-
- struct sigaction sa;
- sa.sa_sigaction = action;
- sigemptyset (&sa.sa_mask);
- sa.sa_flags = SA_SIGINFO;
- if (sigaction (SIGUSR1, &sa, NULL))
- {
- puts ("sigaction failed");
- exit (1);
- }
-
- sem_t sem;
- if (sem_init (&sem, 0, 0))
- {
- puts ("sem_init failed");
- }
-
- sigval_t val;
- val.sival_ptr = &sem;
- for (int i = 0; i < 10; ++i)
- {
- if (pthread_sigqueue (th[i], SIGUSR1, val))
- {
- puts ("pthread_sigqueue failed");
- }
- }
-
-
- for (int i = 0; i < 10; ++i)
- {
- if (sem_wait (&sem))
- {
- puts ("sem_wait failed");
- }
- }
-
- /* Paranoia. */
- tls7mod_action = NULL;
-
- if (dlclose (h))
- {
- puts ("dlclose failed");
- exit (1);
- }
- }
- return 0;
-}
-
-#define TIMEOUT 8
-
-#define TEST_FUNCTION do_test ()
-#include "../test-skeleton.c"
+++ /dev/null
-/* Copyright (C) 2013 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/>. */
-
-/* Dynamic module with TLS to be accessed by a signal handler to check safety
- of that mode. */
-
-#include <semaphore.h>
-#include <signal.h>
-#include <unistd.h>
-
-/* This is an unlikely value to see in incorrectly initialized TLS
- block -- make sure we're initialized properly. */
-static __thread intptr_t tls_data = 0xdeadbeef;
-
-void
-action (int signo, siginfo_t *info, void *ignored)
-{
- if (tls_data != 0xdeadbeef)
- {
- write (STDOUT_FILENO, "wrong TLS value\n", 17);
- _exit (1);
- }
-
- /* arbitrary choice, just write something unique-ish. */
- tls_data = (intptr_t) info;
-}
projects / external / glibc.git / commitdiff