Use STB_SECONDARY on pthread functions in libchjl/pthread/2.22

Use STB_SECONDARY binding on pthread functions in libc so that they will
be preempted by definitions in libpthread at link-time as well as at
run-time.

	* csu/libc-tls.c (__pthread_initialize_minimal): Mark it
	secondary if HAVE_ASM_SECONDARY_DIRECTIVE is defined.
	* misc/error.c (error): Replace pthread_setcancelstate with
	__pthread_setcancelstate.
	(error_at_line): Likewise.
	* posix/wordexp.c (parse_comm): Likewise.
	* stdlib/fmtmsg.c (fmtmsg): Likewise.
	* nptl/Makefile:
	(routines): Add libc-pthread-secondary.
	(CFLAGS-libc-pthread-secondary.c): New.
	* nptl/Versions [HAVE_ASM_SECONDARY_DIRECTIVE] (libc:GLIBC_2.0):
	Add pthread_once.
	[HAVE_ASM_SECONDARY_DIRECTIVE] (libc:GLIBC_PRIVATE): Add
	_pthread_cleanup_pop_restore, _pthread_cleanup_push_defer,
	__pthread_getspecific, __pthread_setspecific,
	__pthread_key_create, __pthread_mutex_lock,
	__pthread_mutex_unlock, __pthread_once,
	__pthread_rwlock_rdlock, __pthread_rwlock_wrlock,
	__pthread_rwlock_unlock and __pthread_unwind.
	[HAVE_ASM_SECONDARY_DIRECTIVE] (libpthread:GLIBC_PRIVATE):
	Likewise.
	* cleanup_defer_compat.c: Include <shlib-compat.h>.
	Add GLIBC_2_0 and GLIBC_PRIVATE versions for
	_pthread_cleanup_pop_restore and _pthread_cleanup_push_defer.
	* nptl/forward.c [HAVE_ASM_SECONDARY_DIRECTIVE] (FORWARD2): New.
	(FORWARD_NORETURN): Likewise.
	(pthread_setcancelstate): Renamed to ...
	(__pthread_setcancelstate): This.
	(pthread_setcancelstate): Add an alias.
	* nptl/libc-pthread-secondary.c: New file.
	* nptl/nptl-init.c (pthread_functions): Don't include secondary
	pthread functions in libc if HAVE_ASM_SECONDARY_DIRECTIVE is
	defined.  Replace ptr_pthread_setcancelstate with
	ptr___pthread_setcancelstate.
	* sysdeps/nptl/pthread-functions.h (pthread_functions): Likewise.
	* nptl/pthread_getspecific.c: Include <shlib-compat.h>.
	Add GLIBC_2_0 and GLIBC_PRIVATE versions for
	__pthread_getspecific.
	* nptl/pthread_key_create.c: Include <shlib-compat.h>.
	Add GLIBC_2_0 and GLIBC_PRIVATE versions for
	__pthread_key_create.
	* nptl/pthread_mutex_lock.c: Include <shlib-compat.h>.
	Add GLIBC_2_0 and GLIBC_PRIVATE versions for
	__pthread_mutex_lock.
	* nptl/pthread_mutex_unlock.c: Include <shlib-compat.h>.
	Add GLIBC_2_0 and GLIBC_PRIVATE versions for
	__pthread_mutex_unlock.
	* nptl/pthread_once.c: Include <shlib-compat.h>.
	Add GLIBC_2_0 and GLIBC_PRIVATE versions for
	__pthread_once.
	* nptl/pthread_rwlock_rdlock.c: Include <shlib-compat.h>.
	Add GLIBC_2_0 and GLIBC_PRIVATE versions for
	__pthread_rwlock_rdlock.
	* nptl/pthread_rwlock_unlock.c: Include <shlib-compat.h>.
	Add GLIBC_2_0 and GLIBC_PRIVATE versions for
	__pthread_rwlock_unlock.
	* nptl/pthread_rwlock_wrlock.c: Include <shlib-compat.h>.
	Add GLIBC_2_0 and GLIBC_PRIVATE versions for
	__pthread_rwlock_wrlock.
	* nptl/pthread_setspecific.c: Include <shlib-compat.h>.
	Add GLIBC_2_0 and GLIBC_PRIVATE versions for
	__pthread_setspecific.
	* nptl/pthreadP.h (__pthread_unwind): Don't mark it weak if
	HAVE_ASM_SECONDARY_DIRECTIVE is defined.
	(__pthread_cond_broadcast_2_0): Declare only if not in libc.
	(__pthread_cond_destroy_2_0): Likewise.
	(__pthread_cond_init_2_0): Likewise.
	(__pthread_cond_signal_2_0): Likewise.
	(__pthread_cond_timedwait_2_0): Likewise.
	(__pthread_cond_wait_2_0): Likewise.
	* scripts/abilist.awk: Support secondary symbols.
	* sysdeps/generic/localplt.data: Add __pthread_getspecific,
	__pthread_key_create, __pthread_once, __pthread_rwlock_rdlock,
	__pthread_rwlock_wrlock, __pthread_rwlock_unlock,
	__pthread_setcancelstate, __pthread_setspecific,
	__pthread_unwind.  _pthread_cleanup_pop_restore and
	_pthread_cleanup_push_defer.
	* sysdeps/unix/sysv/linux/i386/localplt.data: Likewise.
	* sysdeps/x86_64/localplt.data: Likewise.
	* sysdeps/nptl/bits/libc-lockP.h (PTFAVAIL): Defined as 1 if
	HAVE_ASM_SECONDARY_DIRECTIVE is defined.
	(__libc_maybe_call): Always call FUNC if
	HAVE_ASM_SECONDARY_DIRECTIVE is defined.
	(__libc_ptf_call): Likewise.
	(__libc_ptf_call_always): Likewise.
	(__pthread_mutex_init): Don't mark it weak if
	HAVE_ASM_SECONDARY_DIRECTIVE is defined.
	(__pthread_mutex_destroy): Likewise.
	(__pthread_mutex_lock): Likewise.
	(__pthread_mutex_trylock): Likewise.
	(__pthread_mutex_unlock): Likewise.
	(__pthread_mutexattr_init): Likewise.
	(__pthread_mutexattr_destroy): Likewise.
	(__pthread_mutexattr_settype): Likewise.
	(__pthread_rwlock_destroy): Likewise.
	(__pthread_rwlock_rdlock): Likewise.
	(__pthread_rwlock_tryrdlock): Likewise.
	(__pthread_rwlock_wrlock): Likewise.
	(__pthread_rwlock_trywrlock): Likewise.
	(__pthread_rwlock_unlock): Likewise.
	(__pthread_key_create): Likewise.
	(__pthread_setspecific): Likewise.
	(__pthread_getspecific): Likewise.
	(__pthread_once): Likewise.
	(__pthread_initialize): Likewise.
	(__pthread_atfork): Likewise.
	(_pthread_cleanup_push_defer): Likewise.
	(_pthread_cleanup_pop_restore): Likewise.
	(__pthread_setcancelstate): New prototype.
	(pthread_setcancelstate): Renamed to ...
	(__pthread_setcancelstate): This.  Don't mark it weak if
	HAVE_ASM_SECONDARY_DIRECTIVE is defined.
	* sysdeps/nptl/jmp-unwind.c: Include <bits/libc-lock.h>
	instead of <nptl/pthreadP.h>.
	(__pthread_cleanup_upto): Don't mark it weak if
	HAVE_ASM_SECONDARY_DIRECTIVE is defined.
	(_longjmp_unwind): Use __libc_ptf_call.
	* sysdeps/unix/sysv/linux/s390/jmp-unwind.c: Likewise.
	* sysdeps/unix/sysv/linux/fatal-prepare.h (FATAL_PREPARE): Always
	call __pthread_setcancelstate if HAVE_ASM_SECONDARY_DIRECTIVE is
	defined.  Replace pthread_setcancelstate with
	__pthread_setcancelstate.
	* sysdeps/unix/sysv/linux/i386/libc.abilist: Add pthread_once.
	* sysdeps/unix/sysv/linux/x86_64/64/libc.abilist: Likewise.
	* sysdeps/unix/sysv/linux/x86_64/x32/libc.abilist: Likewise.
	* sysdeps/unix/sysv/linux/i386/i486/libc-lowlevellock.S: Make
	__lll_lock_wait_private and __lll_unlock_wake_private weak in
	libc.a.
	* sysdeps/unix/sysv/linux/x86_64/libc-lowlevellock.S: Likewise.
	* sysdeps/unix/sysv/linux/x86_64/cancellation.S (__pthread_unwind):
	Don't mark it weak if HAVE_ASM_SECONDARY_DIRECTIVE is defined.

14 files changed, 110 insertions, 63 deletions

diff --git a/sysdeps/generic/localplt.data b/sysdeps/generic/localplt.data
index 1a40cf9841..5b1463f584 100644
--- a/sysdeps/generic/localplt.data
+++ b/sysdeps/generic/localplt.data
@@ -1,6 +1,18 @@
 # See scripts/check-localplt.awk for how this file is processed.
 # PLT use is required for the malloc family and for matherr because
 # users can define their own functions and have library internals call them.
+# pthread functions may be preempted by libpthread at run-time.
+libc.so: __pthread_getspecific
+libc.so: __pthread_key_create
+libc.so: __pthread_once
+libc.so: __pthread_rwlock_rdlock
+libc.so: __pthread_rwlock_unlock
+libc.so: __pthread_rwlock_wrlock
+libc.so: __pthread_setcancelstate
+libc.so: __pthread_setspecific
+libc.so: __pthread_unwind
+libc.so: _pthread_cleanup_pop_restore
+libc.so: _pthread_cleanup_push_defer
 libc.so: calloc
 libc.so: free
 libc.so: malloc
diff --git a/sysdeps/nptl/bits/libc-lockP.h b/sysdeps/nptl/bits/libc-lockP.h
index f55f6212ec..f5753afb32 100644
--- a/sysdeps/nptl/bits/libc-lockP.h
+++ b/sysdeps/nptl/bits/libc-lockP.h
@@ -99,39 +99,51 @@ typedef pthread_key_t __libc_key_t;
 #define __rtld_lock_initialize(NAME) \
   (void) ((NAME) = (__rtld_lock_recursive_t) _RTLD_LOCK_RECURSIVE_INITIALIZER)
 
+#ifdef HAVE_ASM_SECONDARY_DIRECTIVE
+/* All pthread functions are available.  */
+# define PTFAVAIL(NAME) 1
+
+/* When secondary symbols are used, FUNC is implemented to return ELSE so
+   that we can always call FUNC.  */
+# define __libc_maybe_call(FUNC, ARGS, ELSE) FUNC ARGS
+# define __libc_ptf_call(FUNC, ARGS, ELSE) FUNC ARGS
+# define __libc_ptf_call_always(FUNC, ARGS) FUNC ARGS
+#else
 /* If we check for a weakly referenced symbol and then perform a
    normal jump to it te code generated for some platforms in case of
    PIC is unnecessarily slow.  What would happen is that the function
    is first referenced as data and then it is called indirectly
    through the PLT.  We can make this a direct jump.  */
-#ifdef __PIC__
-# define __libc_maybe_call(FUNC, ARGS, ELSE) \
-  (__extension__ ({ __typeof (FUNC) *_fn = (FUNC); \
-		    _fn != NULL ? (*_fn) ARGS : ELSE; }))
-#else
-# define __libc_maybe_call(FUNC, ARGS, ELSE) \
-  (FUNC != NULL ? FUNC ARGS : ELSE)
-#endif
+# ifdef __PIC__
+#  define __libc_maybe_call(FUNC, ARGS, ELSE) \
+   (__extension__ ({ __typeof (FUNC) *_fn = (FUNC); \
+		     _fn != NULL ? (*_fn) ARGS : ELSE; }))
+# else
+#  define __libc_maybe_call(FUNC, ARGS, ELSE) \
+   (FUNC != NULL ? FUNC ARGS : ELSE)
+# endif
 
 /* Call thread functions through the function pointer table.  */
-#if defined SHARED && IS_IN (libc)
-# define PTFAVAIL(NAME) __libc_pthread_functions_init
-# define __libc_ptf_call(FUNC, ARGS, ELSE) \
+# if defined SHARED && IS_IN (libc) \
+     && !defined HAVE_ASM_SECONDARY_DIRECTIVE
+#  define PTFAVAIL(NAME) __libc_pthread_functions_init
+#  define __libc_ptf_call(FUNC, ARGS, ELSE) \
   (__libc_pthread_functions_init ? PTHFCT_CALL (ptr_##FUNC, ARGS) : ELSE)
-# define __libc_ptf_call_always(FUNC, ARGS) \
+#  define __libc_ptf_call_always(FUNC, ARGS) \
   PTHFCT_CALL (ptr_##FUNC, ARGS)
-#elif IS_IN (libpthread)
-# define PTFAVAIL(NAME) 1
-# define __libc_ptf_call(FUNC, ARGS, ELSE) \
+# elif IS_IN (libpthread)
+#  define PTFAVAIL(NAME) 1
+#  define __libc_ptf_call(FUNC, ARGS, ELSE) \
   FUNC ARGS
-# define __libc_ptf_call_always(FUNC, ARGS) \
+#  define __libc_ptf_call_always(FUNC, ARGS) \
   FUNC ARGS
-#else
-# define PTFAVAIL(NAME) (NAME != NULL)
-# define __libc_ptf_call(FUNC, ARGS, ELSE) \
-  __libc_maybe_call (FUNC, ARGS, ELSE)
-# define __libc_ptf_call_always(FUNC, ARGS) \
+# else
+#  define PTFAVAIL(NAME) (NAME != NULL)
+#  define __libc_ptf_call(FUNC, ARGS, ELSE) \
+   __libc_maybe_call (FUNC, ARGS, ELSE)
+#  define __libc_ptf_call_always(FUNC, ARGS) \
   FUNC ARGS
+# endif
 #endif
 
 
@@ -364,6 +376,8 @@ extern int __pthread_rwlock_unlock (pthread_rwlock_t *__rwlock);
 extern int __pthread_key_create (pthread_key_t *__key,
 				 void (*__destr_function) (void *));
 
+extern int __pthread_setcancelstate (int state, int *oldstate);
+
 extern int __pthread_setspecific (pthread_key_t __key,
 				  const void *__pointer);
 
@@ -379,8 +393,9 @@ extern int __pthread_atfork (void (*__prepare) (void),
 
 
 /* Make the pthread functions weak so that we can elide them from
-   single-threaded processes.  */
-#ifndef __NO_WEAK_PTHREAD_ALIASES
+   single-threaded processes unless secondary symbols are used.  */
+#if !defined __NO_WEAK_PTHREAD_ALIASES \
+    && !defined HAVE_ASM_SECONDARY_DIRECTIVE
 # ifdef weak_extern
 weak_extern (__pthread_mutex_init)
 weak_extern (__pthread_mutex_destroy)
@@ -405,7 +420,7 @@ weak_extern (__pthread_initialize)
 weak_extern (__pthread_atfork)
 weak_extern (_pthread_cleanup_push_defer)
 weak_extern (_pthread_cleanup_pop_restore)
-weak_extern (pthread_setcancelstate)
+weak_extern (__pthread_setcancelstate)
 # else
 #  pragma weak __pthread_mutex_init
 #  pragma weak __pthread_mutex_destroy
@@ -429,7 +444,7 @@ weak_extern (pthread_setcancelstate)
 #  pragma weak __pthread_atfork
 #  pragma weak _pthread_cleanup_push_defer
 #  pragma weak _pthread_cleanup_pop_restore
-#  pragma weak pthread_setcancelstate
+#  pragma weak __pthread_setcancelstate
 # endif
 #endif
 
diff --git a/sysdeps/nptl/jmp-unwind.c b/sysdeps/nptl/jmp-unwind.c
index 8e019867a7..6f19c6215d 100644
--- a/sysdeps/nptl/jmp-unwind.c
+++ b/sysdeps/nptl/jmp-unwind.c
@@ -18,21 +18,17 @@
 
 #include <setjmp.h>
 #include <stddef.h>
-#include <nptl/pthreadP.h>
+#include <bits/libc-lock.h>
 
 extern void __pthread_cleanup_upto (__jmp_buf env, char *targetframe);
+#ifndef HAVE_ASM_SECONDARY_DIRECTIVE
 #pragma weak __pthread_cleanup_upto
+#endif
 
 
 void
 _longjmp_unwind (jmp_buf env, int val)
 {
-#ifdef SHARED
-  if (__libc_pthread_functions_init)
-    PTHFCT_CALL (ptr___pthread_cleanup_upto, (env->__jmpbuf,
-					      CURRENT_STACK_FRAME));
-#else
-  if (__pthread_cleanup_upto != NULL)
-    __pthread_cleanup_upto (env->__jmpbuf, CURRENT_STACK_FRAME);
-#endif
+  __libc_ptf_call (__pthread_cleanup_upto, (env->__jmpbuf,
+					    CURRENT_STACK_FRAME), 0);
 }
diff --git a/sysdeps/nptl/pthread-functions.h b/sysdeps/nptl/pthread-functions.h
index 0784c59cab..f6238ab663 100644
--- a/sysdeps/nptl/pthread-functions.h
+++ b/sysdeps/nptl/pthread-functions.h
@@ -30,6 +30,7 @@ struct xid_command;
    the thread functions.  */
 struct pthread_functions
 {
+#ifndef HAVE_ASM_SECONDARY_DIRECTIVE
   int (*ptr_pthread_attr_destroy) (pthread_attr_t *);
   int (*ptr___pthread_attr_init_2_0) (pthread_attr_t *);
   int (*ptr___pthread_attr_init_2_1) (pthread_attr_t *);
@@ -75,9 +76,8 @@ struct pthread_functions
   int (*ptr_pthread_mutex_lock) (pthread_mutex_t *);
   int (*ptr_pthread_mutex_unlock) (pthread_mutex_t *);
   pthread_t (*ptr_pthread_self) (void);
-  int (*ptr_pthread_setcancelstate) (int, int *);
+  int (*ptr___pthread_setcancelstate) (int, int *);
   int (*ptr_pthread_setcanceltype) (int, int *);
-  void (*ptr___pthread_cleanup_upto) (__jmp_buf, char *);
   int (*ptr___pthread_once) (pthread_once_t *, void (*) (void));
   int (*ptr___pthread_rwlock_rdlock) (pthread_rwlock_t *);
   int (*ptr___pthread_rwlock_wrlock) (pthread_rwlock_t *);
@@ -89,10 +89,12 @@ struct pthread_functions
 					   void (*) (void *), void *);
   void (*ptr__pthread_cleanup_pop_restore) (struct _pthread_cleanup_buffer *,
 					    int);
-#define HAVE_PTR_NTHREADS
-  unsigned int *ptr_nthreads;
   void (*ptr___pthread_unwind) (__pthread_unwind_buf_t *)
        __attribute ((noreturn)) __cleanup_fct_attribute;
+#endif
+  void (*ptr___pthread_cleanup_upto) (__jmp_buf, char *);
+#define HAVE_PTR_NTHREADS
+  unsigned int *ptr_nthreads;
   void (*ptr__nptl_deallocate_tsd) (void);
   int (*ptr__nptl_setxid) (struct xid_command *);
   void (*ptr_freeres) (void);
diff --git a/sysdeps/unix/sysv/linux/fatal-prepare.h b/sysdeps/unix/sysv/linux/fatal-prepare.h
index 45d88ce911..2a89567299 100644
--- a/sysdeps/unix/sysv/linux/fatal-prepare.h
+++ b/sysdeps/unix/sysv/linux/fatal-prepare.h
@@ -19,19 +19,6 @@
 
 /* We have to completely disable cancellation.  assert() must not be a
    cancellation point but the implementation uses write() etc.  */
-#ifdef SHARED
-# include <pthread-functions.h>
-# define FATAL_PREPARE \
-  {									      \
-    if (__libc_pthread_functions_init)					      \
-      PTHFCT_CALL (ptr_pthread_setcancelstate, (PTHREAD_CANCEL_DISABLE,	      \
-						NULL));			      \
-  }
-#else
-# pragma weak pthread_setcancelstate
-# define FATAL_PREPARE \
-  {									      \
-    if (pthread_setcancelstate != NULL)					      \
-      pthread_setcancelstate (PTHREAD_CANCEL_DISABLE, NULL);		      \
-  }
-#endif
+#define FATAL_PREPARE \
+  __libc_ptf_call (__pthread_setcancelstate, \
+		   (PTHREAD_CANCEL_DISABLE, NULL), 0)
diff --git a/sysdeps/unix/sysv/linux/i386/i486/libc-lowlevellock.S b/sysdeps/unix/sysv/linux/i386/i486/libc-lowlevellock.S
index 111e9c88ed..cf3f206445 100644
--- a/sysdeps/unix/sysv/linux/i386/i486/libc-lowlevellock.S
+++ b/sysdeps/unix/sysv/linux/i386/i486/libc-lowlevellock.S
@@ -16,4 +16,10 @@
    License along with the GNU C Library; if not, see
    <http://www.gnu.org/licenses/>.  */
 
+#if IS_IN (libc) && !defined SHARED
+/* Allow libpthread.a to override the ones in libc.a.  */
+	weak_extern (__lll_lock_wait_private)
+	weak_extern (__lll_unlock_wake_private)
+#endif
+
 #include "lowlevellock.S"
diff --git a/sysdeps/unix/sysv/linux/i386/libc.abilist b/sysdeps/unix/sysv/linux/i386/libc.abilist
index fcf1b72ab5..fe41fbd6ac 100644
--- a/sysdeps/unix/sysv/linux/i386/libc.abilist
+++ b/sysdeps/unix/sysv/linux/i386/libc.abilist
@@ -868,6 +868,7 @@ GLIBC_2.0
  pthread_mutex_init F
  pthread_mutex_lock F
  pthread_mutex_unlock F
+ pthread_once F
  pthread_self F
  pthread_setcancelstate F
  pthread_setcanceltype F
diff --git a/sysdeps/unix/sysv/linux/i386/localplt.data b/sysdeps/unix/sysv/linux/i386/localplt.data
index 2e03821dfd..f9efb05c41 100644
--- a/sysdeps/unix/sysv/linux/i386/localplt.data
+++ b/sysdeps/unix/sysv/linux/i386/localplt.data
@@ -6,6 +6,18 @@ libc.so: free + REL R_386_GLOB_DAT
 libc.so: malloc + REL R_386_GLOB_DAT
 libc.so: memalign
 libc.so: realloc
+# pthread functions may be preempted by libpthread at run-time.
+libc.so: __pthread_getspecific
+libc.so: __pthread_key_create
+libc.so: __pthread_once
+libc.so: __pthread_rwlock_rdlock
+libc.so: __pthread_rwlock_unlock
+libc.so: __pthread_rwlock_wrlock
+libc.so: __pthread_setcancelstate
+libc.so: __pthread_setspecific
+libc.so: __pthread_unwind
+libc.so: _pthread_cleanup_pop_restore
+libc.so: _pthread_cleanup_push_defer
 libm.so: matherr
 # The dynamic loader uses __libc_memalign internally to allocate aligned
 # TLS storage. The other malloc family of functions are expected to allow
diff --git a/sysdeps/unix/sysv/linux/s390/jmp-unwind.c b/sysdeps/unix/sysv/linux/s390/jmp-unwind.c
index 52fe1019f2..b7f9080e5a 100644
--- a/sysdeps/unix/sysv/linux/s390/jmp-unwind.c
+++ b/sysdeps/unix/sysv/linux/s390/jmp-unwind.c
@@ -18,10 +18,12 @@
 
 #include <setjmp.h>
 #include <stddef.h>
-#include <nptl/pthreadP.h>
+#include <bits/libc-lock.h>
 
 extern void __pthread_cleanup_upto (__jmp_buf env, char *targetframe);
+#ifndef HAVE_ASM_SECONDARY_DIRECTIVE
 #pragma weak __pthread_cleanup_upto
+#endif
 
 
 void
@@ -29,11 +31,5 @@ _longjmp_unwind (jmp_buf env, int val)
 {
   char local_var;
 
-#ifdef SHARED
-  if (__libc_pthread_functions_init)
-    PTHFCT_CALL (ptr___pthread_cleanup_upto, (env->__jmpbuf, &local_var));
-#else
-  if (__pthread_cleanup_upto != NULL)
-    __pthread_cleanup_upto (env->__jmpbuf, &local_var);
-#endif
+  __libc_ptf_call (__pthread_cleanup_upto, (env->__jmpbuf, &local_var), 0);
 }
diff --git a/sysdeps/unix/sysv/linux/x86_64/64/libc.abilist b/sysdeps/unix/sysv/linux/x86_64/64/libc.abilist
index b377b04e48..5be5d5ad05 100644
--- a/sysdeps/unix/sysv/linux/x86_64/64/libc.abilist
+++ b/sysdeps/unix/sysv/linux/x86_64/64/libc.abilist
@@ -1299,6 +1299,7 @@ GLIBC_2.2.5
  pthread_mutex_init F
  pthread_mutex_lock F
  pthread_mutex_unlock F
+ pthread_once F
  pthread_self F
  pthread_setcancelstate F
  pthread_setcanceltype F
diff --git a/sysdeps/unix/sysv/linux/x86_64/cancellation.S b/sysdeps/unix/sysv/linux/x86_64/cancellation.S
index 4c34bebc42..52a27dcc5e 100644
--- a/sysdeps/unix/sysv/linux/x86_64/cancellation.S
+++ b/sysdeps/unix/sysv/linux/x86_64/cancellation.S
@@ -26,7 +26,7 @@
 #  define __pthread_unwind __GI___pthread_unwind
 # endif
 #else
-# ifndef SHARED
+# if !defined SHARED && !defined HAVE_ASM_SECONDARY_DIRECTIVE
 	.weak __pthread_unwind
 # endif
 #endif
diff --git a/sysdeps/unix/sysv/linux/x86_64/libc-lowlevellock.S b/sysdeps/unix/sysv/linux/x86_64/libc-lowlevellock.S
index 111e9c88ed..cf3f206445 100644
--- a/sysdeps/unix/sysv/linux/x86_64/libc-lowlevellock.S
+++ b/sysdeps/unix/sysv/linux/x86_64/libc-lowlevellock.S
@@ -16,4 +16,10 @@
    License along with the GNU C Library; if not, see
    <http://www.gnu.org/licenses/>.  */
 
+#if IS_IN (libc) && !defined SHARED
+/* Allow libpthread.a to override the ones in libc.a.  */
+	weak_extern (__lll_lock_wait_private)
+	weak_extern (__lll_unlock_wake_private)
+#endif
+
 #include "lowlevellock.S"
diff --git a/sysdeps/unix/sysv/linux/x86_64/x32/libc.abilist b/sysdeps/unix/sysv/linux/x86_64/x32/libc.abilist
index 5f7032980b..ac95bfa196 100644
--- a/sysdeps/unix/sysv/linux/x86_64/x32/libc.abilist
+++ b/sysdeps/unix/sysv/linux/x86_64/x32/libc.abilist
@@ -1448,6 +1448,7 @@ GLIBC_2.16
  pthread_mutex_init F
  pthread_mutex_lock F
  pthread_mutex_unlock F
+ pthread_once F
  pthread_self F
  pthread_setcancelstate F
  pthread_setcanceltype F
diff --git a/sysdeps/x86_64/localplt.data b/sysdeps/x86_64/localplt.data
index d140476dfe..6ca015229d 100644
--- a/sysdeps/x86_64/localplt.data
+++ b/sysdeps/x86_64/localplt.data
@@ -3,6 +3,18 @@
 # users can define their own functions and have library internals call them.
 # Linker in binutils 2.26 and newer consolidates R_X86_64_JUMP_SLOT
 # relocation with R_X86_64_GLOB_DAT relocation against the same symbol.
+# pthread functions may be preempted by libpthread at run-time.
+libc.so: __pthread_getspecific
+libc.so: __pthread_key_create
+libc.so: __pthread_once
+libc.so: __pthread_rwlock_rdlock
+libc.so: __pthread_rwlock_unlock
+libc.so: __pthread_rwlock_wrlock
+libc.so: __pthread_setcancelstate
+libc.so: __pthread_setspecific
+libc.so: __pthread_unwind
+libc.so: _pthread_cleanup_pop_restore
+libc.so: _pthread_cleanup_push_defer
 libc.so: calloc
 libc.so: free + RELA R_X86_64_GLOB_DAT
 libc.so: malloc + RELA R_X86_64_GLOB_DAT