c0a777e8d0
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.
154 lines
4.9 KiB
C
154 lines
4.9 KiB
C
/* Defintions for lowlevel handling in ld.so.
|
|
Copyright (C) 2006 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, write to the Free
|
|
Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
|
|
02111-1307 USA. */
|
|
|
|
#ifndef _RTLD_LOWLEVEL_H
|
|
#define _RTLD_LOWLEVEL_H 1
|
|
|
|
#include <atomic.h>
|
|
#include <lowlevellock.h>
|
|
|
|
|
|
/* Special multi-reader lock used in ld.so. */
|
|
#define __RTLD_MRLOCK_WRITER 1
|
|
#define __RTLD_MRLOCK_RWAIT 2
|
|
#define __RTLD_MRLOCK_WWAIT 4
|
|
#define __RTLD_MRLOCK_RBITS \
|
|
~(__RTLD_MRLOCK_WRITER | __RTLD_MRLOCK_RWAIT | __RTLD_MRLOCK_WWAIT)
|
|
#define __RTLD_MRLOCK_INC 8
|
|
#define __RTLD_MRLOCK_TRIES 5
|
|
|
|
|
|
typedef int __rtld_mrlock_t;
|
|
|
|
|
|
#define __rtld_mrlock_define(CLASS,NAME) \
|
|
CLASS __rtld_mrlock_t NAME;
|
|
|
|
|
|
#define _RTLD_MRLOCK_INITIALIZER 0
|
|
#define __rtld_mrlock_initialize(NAME) \
|
|
(void) ((NAME) = 0
|
|
|
|
|
|
#define __rtld_mrlock_lock(lock) \
|
|
do { \
|
|
__label__ out; \
|
|
while (1) \
|
|
{ \
|
|
int oldval; \
|
|
for (int tries = 0; tries < __RTLD_MRLOCK_TRIES; ++tries) \
|
|
{ \
|
|
oldval = lock; \
|
|
while (__builtin_expect ((oldval \
|
|
& (__RTLD_MRLOCK_WRITER \
|
|
| __RTLD_MRLOCK_WWAIT)) \
|
|
== 0, 1)) \
|
|
{ \
|
|
int newval = ((oldval & __RTLD_MRLOCK_RBITS) \
|
|
+ __RTLD_MRLOCK_INC); \
|
|
int ret = atomic_compare_and_exchange_val_acq (&(lock), \
|
|
newval, \
|
|
oldval); \
|
|
if (__builtin_expect (ret == oldval, 1)) \
|
|
goto out; \
|
|
oldval = ret; \
|
|
} \
|
|
atomic_delay (); \
|
|
} \
|
|
if ((oldval & __RTLD_MRLOCK_RWAIT) == 0) \
|
|
{ \
|
|
atomic_or (&(lock), __RTLD_MRLOCK_RWAIT); \
|
|
oldval |= __RTLD_MRLOCK_RWAIT; \
|
|
} \
|
|
lll_futex_wait (lock, oldval); \
|
|
} \
|
|
out:; \
|
|
} while (0)
|
|
|
|
|
|
#define __rtld_mrlock_unlock(lock) \
|
|
do { \
|
|
int oldval = atomic_exchange_and_add (&(lock), -__RTLD_MRLOCK_INC); \
|
|
if (__builtin_expect ((oldval \
|
|
& (__RTLD_MRLOCK_RBITS | __RTLD_MRLOCK_WWAIT)) \
|
|
== (__RTLD_MRLOCK_INC | __RTLD_MRLOCK_WWAIT), 0)) \
|
|
/* We have to wake all threads since there might be some queued \
|
|
readers already. */ \
|
|
lll_futex_wake (&(lock), 0x7fffffff); \
|
|
} while (0)
|
|
|
|
|
|
/* There can only ever be one thread trying to get the exclusive lock. */
|
|
#define __rtld_mrlock_change(lock) \
|
|
do { \
|
|
__label__ out; \
|
|
while (1) \
|
|
{ \
|
|
int oldval; \
|
|
for (int tries = 0; tries < __RTLD_MRLOCK_TRIES; ++tries) \
|
|
{ \
|
|
oldval = lock; \
|
|
while (__builtin_expect ((oldval & __RTLD_MRLOCK_RBITS) == 0, 1)) \
|
|
{ \
|
|
int newval = ((oldval & __RTLD_MRLOCK_RWAIT) \
|
|
+ __RTLD_MRLOCK_WRITER); \
|
|
int ret = atomic_compare_and_exchange_val_acq (&(lock), \
|
|
newval, \
|
|
oldval); \
|
|
if (__builtin_expect (ret == oldval, 1)) \
|
|
goto out; \
|
|
oldval = ret; \
|
|
} \
|
|
atomic_delay (); \
|
|
} \
|
|
atomic_or (&(lock), __RTLD_MRLOCK_WWAIT); \
|
|
oldval |= __RTLD_MRLOCK_WWAIT; \
|
|
lll_futex_wait (lock, oldval); \
|
|
} \
|
|
out:; \
|
|
} while (0)
|
|
|
|
|
|
#define __rtld_mrlock_done(lock) \
|
|
do { \
|
|
int oldval = atomic_exchange_and_add (&(lock), -__RTLD_MRLOCK_WRITER); \
|
|
if (__builtin_expect ((oldval & __RTLD_MRLOCK_RWAIT) != 0, 0)) \
|
|
lll_futex_wake (&(lock), 0x7fffffff); \
|
|
} while (0)
|
|
|
|
|
|
/* Function to wait for variable become zero. Used in ld.so for
|
|
reference counters. */
|
|
#define __rtld_waitzero(word) \
|
|
do { \
|
|
while (1) \
|
|
{ \
|
|
int val = word; \
|
|
if (val == 0) \
|
|
break; \
|
|
lll_futex_wait (&(word), val); \
|
|
} \
|
|
} while (0)
|
|
|
|
|
|
#define __rtld_notify(word) \
|
|
lll_futex_wake (&(word), 1)
|
|
|
|
#endif
|