MFC r318539 r318580 r318581 r318584 r318749 r318952 r318953 r318955

libthr: fix warnings at WARNS=6

Fix warnings about the following when WARNS=6 (which I will commit soon):

- casting away const
- no previous 'extern' declaration for non-static variable
- others as explained by #pragmas and comments
- unused parameters

libthr: disable thread-safety warnings

These warnings don't make sense for code that implements
the locking primitives.

libthr: change CHECK_AND_INIT_RWLOCK to an inline function

This was prompted by a compiler warning about 'ret' shadowing
a local variable in the callers of the macro.

libthr: Use CLI flags instead of pragmas to disable warnings

People tweaking the build system or compilers tend to look into
the Makefile and not into the source.  Having some warning controls
in the Makefile and some in the source code is surprising.

Pragmas have the advantage that they leave the warnings enabled
for more code, but that advantage isn't very relevant in these cases.

libthr: fix warnings from GCC when WARNS=6

Fix warnings about:
- redundant declarations
- a local variable shadowing a global function (dlinfo)
- an old-style function definition (with an empty parameter list)
- a variable that is possibly used uninitialized

libthr: prevent setcontext() from masking SIGTHR

__thr_setcontext() mistakenly tested for the presence of SIGCANCEL
in its local ucontext_t instead of the parameter. Therefore,
if a thread calls setcontext() with a context whose signal mask
contains SIGTHR (a.k.a. SIGCANCEL), that signal will be blocked,
preventing the thread from being cancelled or suspended.

Sponsored by:	Dell EMC

18 files changed, 106 insertions, 68 deletions

diff --git a/lib/libc/include/libc_private.h b/lib/libc/include/libc_private.h
index 384f61f..2134f34 100644
--- a/lib/libc/include/libc_private.h
+++ b/lib/libc/include/libc_private.h
@@ -42,7 +42,10 @@
  * or more threads. It is used to avoid calling locking functions
  * when they are not required.
  */
+#ifndef __LIBC_ISTHREADED_DECLARED
+#define __LIBC_ISTHREADED_DECLARED
 extern int	__isthreaded;
+#endif
 
 /*
  * Elf_Auxinfo *__elf_aux_vector, the pointer to the ELF aux vector
diff --git a/lib/libthr/Makefile b/lib/libthr/Makefile
index 5b3e3bf..60cb420 100644
--- a/lib/libthr/Makefile
+++ b/lib/libthr/Makefile
@@ -17,6 +17,7 @@ MK_SSP=	no
 LIB=thr
 SHLIB_MAJOR= 3
 WARNS?=	3
+NO_WTHREAD_SAFETY=1
 CFLAGS+=-DPTHREAD_KERNEL
 CFLAGS+=-I${SRCTOP}/lib/libc/include -I${.CURDIR}/thread \
 	-I${SRCTOP}/include
@@ -27,6 +28,12 @@ CFLAGS+=-I${SRCTOP}/libexec/rtld-elf/${MACHINE_CPUARCH}
 CFLAGS+=-I${SRCTOP}/lib/libthread_db
 CFLAGS+=-Winline
 
+CFLAGS.thr_stack.c+=	-Wno-cast-align
+.include <bsd.compiler.mk>
+.if !(${COMPILER_TYPE} == "gcc" && ${COMPILER_VERSION} < 40300)
+CFLAGS.thr_symbols.c+=	-Wno-missing-variable-declarations
+.endif
+
 .ifndef NO_THREAD_UNWIND_STACK
 CFLAGS+=-fexceptions
 CFLAGS+=-D_PTHREAD_FORCED_UNWIND
diff --git a/lib/libthr/arch/aarch64/include/pthread_md.h b/lib/libthr/arch/aarch64/include/pthread_md.h
index 14c1893..d14bce2 100644
--- a/lib/libthr/arch/aarch64/include/pthread_md.h
+++ b/lib/libthr/arch/aarch64/include/pthread_md.h
@@ -72,8 +72,6 @@ _tcb_get(void)
 	return (tcb);
 }
 
-extern struct pthread *_thr_initial;
-
 static __inline struct pthread *
 _get_curthread(void)
 {
diff --git a/lib/libthr/arch/arm/include/pthread_md.h b/lib/libthr/arch/arm/include/pthread_md.h
index 9a6b523..4ae7971 100644
--- a/lib/libthr/arch/arm/include/pthread_md.h
+++ b/lib/libthr/arch/arm/include/pthread_md.h
@@ -75,8 +75,6 @@ _tcb_get(void)
 #endif
 }
 
-extern struct pthread *_thr_initial;
-
 static __inline struct pthread *
 _get_curthread(void)
 {
diff --git a/lib/libthr/arch/mips/include/pthread_md.h b/lib/libthr/arch/mips/include/pthread_md.h
index 32af964..22aa3db 100644
--- a/lib/libthr/arch/mips/include/pthread_md.h
+++ b/lib/libthr/arch/mips/include/pthread_md.h
@@ -70,8 +70,6 @@ _tcb_get(void)
 	return tcb;
 }
 
-extern struct pthread *_thr_initial;
-
 static __inline struct pthread *
 _get_curthread(void)
 {
diff --git a/lib/libthr/arch/powerpc/include/pthread_md.h b/lib/libthr/arch/powerpc/include/pthread_md.h
index 544ee1c..699233e 100644
--- a/lib/libthr/arch/powerpc/include/pthread_md.h
+++ b/lib/libthr/arch/powerpc/include/pthread_md.h
@@ -80,8 +80,6 @@ _tcb_get(void)
 	return ((struct tcb *)(_tp - TP_OFFSET));
 }
 
-extern struct pthread *_thr_initial;
-
 static __inline struct pthread *
 _get_curthread(void)
 {
diff --git a/lib/libthr/arch/riscv/include/pthread_md.h b/lib/libthr/arch/riscv/include/pthread_md.h
index 3f51078..499da5f 100644
--- a/lib/libthr/arch/riscv/include/pthread_md.h
+++ b/lib/libthr/arch/riscv/include/pthread_md.h
@@ -78,8 +78,6 @@ _tcb_get(void)
 	return ((struct tcb *)(_tp - TP_OFFSET));
 }
 
-extern struct pthread *_thr_initial;
-
 static __inline struct pthread *
 _get_curthread(void)
 {
diff --git a/lib/libthr/thread/thr_attr.c b/lib/libthr/thread/thr_attr.c
index ff9eb2d5..a790483 100644
--- a/lib/libthr/thread/thr_attr.c
+++ b/lib/libthr/thread/thr_attr.c
@@ -607,7 +607,7 @@ _pthread_attr_setaffinity_np(pthread_attr_t *pattr, size_t cpusetsize,
 			/* Kernel checks invalid bits, we check it here too. */
 			size_t i;
 			for (i = kern_size; i < cpusetsize; ++i) {
-				if (((char *)cpusetp)[i])
+				if (((const char *)cpusetp)[i])
 					return (EINVAL);
 			}
 		}
diff --git a/lib/libthr/thread/thr_exit.c b/lib/libthr/thread/thr_exit.c
index a2d67de..1a34394 100644
--- a/lib/libthr/thread/thr_exit.c
+++ b/lib/libthr/thread/thr_exit.c
@@ -46,8 +46,6 @@ __FBSDID("$FreeBSD$");
 #include "libc_private.h"
 #include "thr_private.h"
 
-void	_pthread_exit(void *status);
-
 static void	exit_thread(void) __dead2;
 
 __weak_reference(_pthread_exit, pthread_exit);
@@ -72,7 +70,7 @@ static void
 thread_uw_init(void)
 {
 	static int inited = 0;
-	Dl_info dlinfo;
+	Dl_info dli;
 	void *handle;
 	void *forcedunwind, *getcfa;
 
@@ -80,12 +78,12 @@ thread_uw_init(void)
 	    return;
 	handle = RTLD_DEFAULT;
 	if ((forcedunwind = dlsym(handle, "_Unwind_ForcedUnwind")) != NULL) {
-	    if (dladdr(forcedunwind, &dlinfo)) {
+	    if (dladdr(forcedunwind, &dli)) {
 		/*
 		 * Make sure the address is always valid by holding the library,
 		 * also assume functions are in same library.
 		 */
-		if ((handle = dlopen(dlinfo.dli_fname, RTLD_LAZY)) != NULL) {
+		if ((handle = dlopen(dli.dli_fname, RTLD_LAZY)) != NULL) {
 		    forcedunwind = dlsym(handle, "_Unwind_ForcedUnwind");
 		    getcfa = dlsym(handle, "_Unwind_GetCFA");
 		    if (forcedunwind != NULL && getcfa != NULL) {
@@ -119,7 +117,8 @@ _Unwind_GetCFA(struct _Unwind_Context *context)
 #endif /* PIC */
 
 static void
-thread_unwind_cleanup(_Unwind_Reason_Code code, struct _Unwind_Exception *e)
+thread_unwind_cleanup(_Unwind_Reason_Code code __unused,
+    struct _Unwind_Exception *e __unused)
 {
 	/*
 	 * Specification said that _Unwind_Resume should not be used here,
@@ -130,10 +129,10 @@ thread_unwind_cleanup(_Unwind_Reason_Code code, struct _Unwind_Exception *e)
 }
 
 static _Unwind_Reason_Code
-thread_unwind_stop(int version, _Unwind_Action actions,
-	int64_t exc_class,
-	struct _Unwind_Exception *exc_obj,
-	struct _Unwind_Context *context, void *stop_parameter)
+thread_unwind_stop(int version __unused, _Unwind_Action actions,
+	int64_t exc_class __unused,
+	struct _Unwind_Exception *exc_obj __unused,
+	struct _Unwind_Context *context, void *stop_parameter __unused)
 {
 	struct pthread *curthread = _get_curthread();
 	struct pthread_cleanup *cur;
diff --git a/lib/libthr/thread/thr_kern.c b/lib/libthr/thread/thr_kern.c
index 6463f1d..64128b4 100644
--- a/lib/libthr/thread/thr_kern.c
+++ b/lib/libthr/thread/thr_kern.c
@@ -62,7 +62,7 @@ _thr_setthreaded(int threaded)
 }
 
 void
-_thr_assert_lock_level()
+_thr_assert_lock_level(void)
 {
 	PANIC("locklevel <= 0");
 }
diff --git a/lib/libthr/thread/thr_list.c b/lib/libthr/thread/thr_list.c
index ae1f124..70b85bc 100644
--- a/lib/libthr/thread/thr_list.c
+++ b/lib/libthr/thread/thr_list.c
@@ -35,8 +35,8 @@ __FBSDID("$FreeBSD$");
 #include <string.h>
 #include <pthread.h>
 
-#include "thr_private.h"
 #include "libc_private.h"
+#include "thr_private.h"
 
 /*#define DEBUG_THREAD_LIST */
 #ifdef DEBUG_THREAD_LIST
diff --git a/lib/libthr/thread/thr_mutex.c b/lib/libthr/thread/thr_mutex.c
index 877bd37..4ab7720 100644
--- a/lib/libthr/thread/thr_mutex.c
+++ b/lib/libthr/thread/thr_mutex.c
@@ -70,8 +70,6 @@ int	__pthread_mutex_trylock(pthread_mutex_t *mutex);
 int	__pthread_mutex_lock(pthread_mutex_t *mutex);
 int	__pthread_mutex_timedlock(pthread_mutex_t *mutex,
 		const struct timespec *abstime);
-int	_pthread_mutex_init_calloc_cb(pthread_mutex_t *mutex,
-    		void *(calloc_cb)(size_t, size_t));
 int	_pthread_mutex_getspinloops_np(pthread_mutex_t *mutex, int *count);
 int	_pthread_mutex_setspinloops_np(pthread_mutex_t *mutex, int count);
 int	__pthread_mutex_setspinloops_np(pthread_mutex_t *mutex, int count);
@@ -712,6 +710,7 @@ mutex_lock_common(struct pthread_mutex *m, const struct timespec *abstime,
 	struct pthread *curthread;
 	int ret, robust;
 
+	robust = 0;  /* pacify gcc */
 	curthread  = _get_curthread();
 	if (!cvattach && m->m_flags & PMUTEX_FLAG_PRIVATE)
 		THR_CRITICAL_ENTER(curthread);
diff --git a/lib/libthr/thread/thr_private.h b/lib/libthr/thread/thr_private.h
index 56ecdb4..4c9245e 100644
--- a/lib/libthr/thread/thr_private.h
+++ b/lib/libthr/thread/thr_private.h
@@ -69,6 +69,9 @@ __NULLABILITY_PRAGMA_PUSH
 	WEAK_REF(func, SYM_FBP10(sym));			\
 	SYM_DEFAULT(sym, SYM_FBP10(sym), FBSDprivate_1.0)
 
+struct pthread;
+extern struct pthread	*_thr_initial __hidden;
+
 #include "pthread_md.h"
 #include "thr_umtx.h"
 #include "thread_db.h"
@@ -701,14 +704,16 @@ do {								\
 	(curthr->report_events && 			\
 	 (((curthr)->event_mask | _thread_event_mask ) & e) != 0)
 
+#ifndef __LIBC_ISTHREADED_DECLARED
+#define __LIBC_ISTHREADED_DECLARED
 extern int __isthreaded;
+#endif
 
 /*
  * Global variables for the pthread kernel.
  */
 
 extern char		*_usrstack __hidden;
-extern struct pthread	*_thr_initial __hidden;
 
 /* For debugger */
 extern int		_libthr_debug;
@@ -835,8 +840,10 @@ int	_sched_yield(void);
 void	_pthread_cleanup_push(void (*)(void *), void *);
 void	_pthread_cleanup_pop(int);
 void	_pthread_exit_mask(void *status, sigset_t *mask) __dead2 __hidden;
+#ifndef _LIBC_PRIVATE_H_
 void	_pthread_cancel_enter(int maycancel);
 void 	_pthread_cancel_leave(int maycancel);
+#endif
 int	_pthread_mutex_consistent(pthread_mutex_t * _Nonnull);
 int	_pthread_mutexattr_getrobust(pthread_mutexattr_t * _Nonnull __restrict,
 	    int * _Nonnull __restrict);
@@ -844,46 +851,56 @@ int	_pthread_mutexattr_setrobust(pthread_mutexattr_t * _Nonnull, int);
 
 /* #include <fcntl.h> */
 #ifdef  _SYS_FCNTL_H_
+#ifndef _LIBC_PRIVATE_H_
 int     __sys_fcntl(int, int, ...);
 int     __sys_openat(int, const char *, int, ...);
-#endif
+#endif /* _LIBC_PRIVATE_H_ */
+#endif /* _SYS_FCNTL_H_ */
 
 /* #include <signal.h> */
 #ifdef _SIGNAL_H_
 int	__sys_kill(pid_t, int);
-int     __sys_sigaction(int, const struct sigaction *, struct sigaction *);
+int     __sys_sigaltstack(const struct sigaltstack *, struct sigaltstack *);
 int     __sys_sigpending(sigset_t *);
+int     __sys_sigreturn(const ucontext_t *);
+#ifndef _LIBC_PRIVATE_H_
+int     __sys_sigaction(int, const struct sigaction *, struct sigaction *);
 int     __sys_sigprocmask(int, const sigset_t *, sigset_t *);
 int     __sys_sigsuspend(const sigset_t *);
-int     __sys_sigreturn(const ucontext_t *);
-int     __sys_sigaltstack(const struct sigaltstack *, struct sigaltstack *);
-int	__sys_sigwait(const sigset_t *, int *);
 int	__sys_sigtimedwait(const sigset_t *, siginfo_t *,
 		const struct timespec *);
+int	__sys_sigwait(const sigset_t *, int *);
 int	__sys_sigwaitinfo(const sigset_t *set, siginfo_t *info);
-#endif
+#endif /* _LIBC_PRIVATE_H_ */
+#endif /* _SYS_FCNTL_H_ */
 
 /* #include <time.h> */
 #ifdef	_TIME_H_
+#ifndef _LIBC_PRIVATE_H_
 int	__sys_clock_nanosleep(clockid_t, int, const struct timespec *,
 	    struct timespec *);
 int	__sys_nanosleep(const struct timespec *, struct timespec *);
-#endif
+#endif /* _LIBC_PRIVATE_H_ */
+#endif /* _SYS_FCNTL_H_ */
 
 /* #include <sys/ucontext.h> */
 #ifdef _SYS_UCONTEXT_H_
+#ifndef _LIBC_PRIVATE_H_
 int	__sys_setcontext(const ucontext_t *ucp);
 int	__sys_swapcontext(ucontext_t *oucp, const ucontext_t *ucp);
-#endif
+#endif /* _LIBC_PRIVATE_H_ */
+#endif /* _SYS_FCNTL_H_ */
 
 /* #include <unistd.h> */
 #ifdef  _UNISTD_H_
+void	__sys_exit(int);
+pid_t	__sys_getpid(void);
+#ifndef _LIBC_PRIVATE_H_
 int     __sys_close(int);
 int	__sys_fork(void);
-pid_t	__sys_getpid(void);
 ssize_t __sys_read(int, void *, size_t);
-void	__sys_exit(int);
-#endif
+#endif /* _LIBC_PRIVATE_H_ */
+#endif /* _SYS_FCNTL_H_ */
 
 static inline int
 _thr_isthreaded(void)
diff --git a/lib/libthr/thread/thr_rwlock.c b/lib/libthr/thread/thr_rwlock.c
index 748eb52..105b35c 100644
--- a/lib/libthr/thread/thr_rwlock.c
+++ b/lib/libthr/thread/thr_rwlock.c
@@ -49,27 +49,42 @@ __weak_reference(_pthread_rwlock_unlock, pthread_rwlock_unlock);
 __weak_reference(_pthread_rwlock_wrlock, pthread_rwlock_wrlock);
 __weak_reference(_pthread_rwlock_timedwrlock, pthread_rwlock_timedwrlock);
 
-#define CHECK_AND_INIT_RWLOCK							\
-	if (*rwlock == THR_PSHARED_PTR) {					\
-		prwlock = __thr_pshared_offpage(rwlock, 0);			\
-		if (prwlock == NULL)						\
-			return (EINVAL);					\
-	} else if (__predict_false((prwlock = (*rwlock)) <=			\
-	    THR_RWLOCK_DESTROYED)) {						\
-		if (prwlock == THR_RWLOCK_INITIALIZER) {			\
-			int ret;						\
-			ret = init_static(_get_curthread(), rwlock);		\
-			if (ret)						\
-				return (ret);					\
-		} else if (prwlock == THR_RWLOCK_DESTROYED) {			\
-			return (EINVAL);					\
-		}								\
-		prwlock = *rwlock;						\
-	}
+static int init_static(struct pthread *thread, pthread_rwlock_t *rwlock);
+static int init_rwlock(pthread_rwlock_t *rwlock, pthread_rwlock_t *rwlock_out);
 
-/*
- * Prototypes
- */
+static int __always_inline
+check_and_init_rwlock(pthread_rwlock_t *rwlock, pthread_rwlock_t *rwlock_out)
+{
+	if (__predict_false(*rwlock == THR_PSHARED_PTR ||
+	    *rwlock <= THR_RWLOCK_DESTROYED))
+		return (init_rwlock(rwlock, rwlock_out));
+	*rwlock_out = *rwlock;
+	return (0);
+}
+
+static int __noinline
+init_rwlock(pthread_rwlock_t *rwlock, pthread_rwlock_t *rwlock_out)
+{
+	pthread_rwlock_t prwlock;
+	int ret;
+
+	if (*rwlock == THR_PSHARED_PTR) {
+		prwlock = __thr_pshared_offpage(rwlock, 0);
+		if (prwlock == NULL)
+			return (EINVAL);
+	} else if ((prwlock = *rwlock) <= THR_RWLOCK_DESTROYED) {
+		if (prwlock == THR_RWLOCK_INITIALIZER) {
+			ret = init_static(_get_curthread(), rwlock);
+			if (ret != 0)
+				return (ret);
+		} else if (prwlock == THR_RWLOCK_DESTROYED) {
+			return (EINVAL);
+		}
+		prwlock = *rwlock;
+	}
+	*rwlock_out = prwlock;
+	return (0);
+}
 
 static int
 rwlock_init(pthread_rwlock_t *rwlock, const pthread_rwlockattr_t *attr)
@@ -148,7 +163,9 @@ rwlock_rdlock_common(pthread_rwlock_t *rwlock, const struct timespec *abstime)
 	int flags;
 	int ret;
 
-	CHECK_AND_INIT_RWLOCK
+	ret = check_and_init_rwlock(rwlock, &prwlock);
+	if (ret != 0)
+		return (ret);
 
 	if (curthread->rdlock_count) {
 		/*
@@ -220,7 +237,9 @@ _pthread_rwlock_tryrdlock (pthread_rwlock_t *rwlock)
 	int flags;
 	int ret;
 
-	CHECK_AND_INIT_RWLOCK
+	ret = check_and_init_rwlock(rwlock, &prwlock);
+	if (ret != 0)
+		return (ret);
 
 	if (curthread->rdlock_count) {
 		/*
@@ -253,7 +272,9 @@ _pthread_rwlock_trywrlock (pthread_rwlock_t *rwlock)
 	pthread_rwlock_t prwlock;
 	int ret;
 
-	CHECK_AND_INIT_RWLOCK
+	ret = check_and_init_rwlock(rwlock, &prwlock);
+	if (ret != 0)
+		return (ret);
 
 	ret = _thr_rwlock_trywrlock(&prwlock->lock);
 	if (ret == 0)
@@ -268,7 +289,9 @@ rwlock_wrlock_common (pthread_rwlock_t *rwlock, const struct timespec *abstime)
 	pthread_rwlock_t prwlock;
 	int ret;
 
-	CHECK_AND_INIT_RWLOCK
+	ret = check_and_init_rwlock(rwlock, &prwlock);
+	if (ret != 0)
+		return (ret);
 
 	/*
 	 * POSIX said the validity of the abstimeout parameter need
diff --git a/lib/libthr/thread/thr_sig.c b/lib/libthr/thread/thr_sig.c
index 8241539..978ae61 100644
--- a/lib/libthr/thread/thr_sig.c
+++ b/lib/libthr/thread/thr_sig.c
@@ -441,7 +441,7 @@ _thr_signal_init(int dlopened)
 }
 
 void
-_thr_sigact_unload(struct dl_phdr_info *phdr_info)
+_thr_sigact_unload(struct dl_phdr_info *phdr_info __unused)
 {
 #if 0
 	struct pthread *curthread = _get_curthread();
@@ -736,8 +736,8 @@ __thr_setcontext(const ucontext_t *ucp)
 		errno = EINVAL;
 		return (-1);
 	}
-	if (!SIGISMEMBER(uc.uc_sigmask, SIGCANCEL))
-		return __sys_setcontext(ucp);
+	if (!SIGISMEMBER(ucp->uc_sigmask, SIGCANCEL))
+		return (__sys_setcontext(ucp));
 	(void) memcpy(&uc, ucp, sizeof(uc));
 	SIGDELSET(uc.uc_sigmask, SIGCANCEL);
 	return (__sys_setcontext(&uc));
diff --git a/lib/libthr/thread/thr_spec.c b/lib/libthr/thread/thr_spec.c
index 46d4ddf..303e34e 100644
--- a/lib/libthr/thread/thr_spec.c
+++ b/lib/libthr/thread/thr_spec.c
@@ -42,7 +42,7 @@ __FBSDID("$FreeBSD$");
 
 #include "thr_private.h"
 
-struct pthread_key _thread_keytable[PTHREAD_KEYS_MAX];
+static struct pthread_key _thread_keytable[PTHREAD_KEYS_MAX];
 
 __weak_reference(_pthread_key_create, pthread_key_create);
 __weak_reference(_pthread_key_delete, pthread_key_delete);
diff --git a/lib/libthr/thread/thr_umtx.c b/lib/libthr/thread/thr_umtx.c
index cd2b101..085e04e 100644
--- a/lib/libthr/thread/thr_umtx.c
+++ b/lib/libthr/thread/thr_umtx.c
@@ -168,7 +168,7 @@ __thr_umutex_timedlock(struct umutex *mtx, uint32_t id,
 }
 
 int
-__thr_umutex_unlock(struct umutex *mtx, uint32_t id)
+__thr_umutex_unlock(struct umutex *mtx)
 {
 
 	return (_umtx_op_err(mtx, UMTX_OP_MUTEX_UNLOCK, 0, 0, 0));
diff --git a/lib/libthr/thread/thr_umtx.h b/lib/libthr/thread/thr_umtx.h
index fff8729..5dae304 100644
--- a/lib/libthr/thread/thr_umtx.h
+++ b/lib/libthr/thread/thr_umtx.h
@@ -44,7 +44,7 @@ int __thr_umutex_lock(struct umutex *mtx, uint32_t id) __hidden;
 int __thr_umutex_lock_spin(struct umutex *mtx, uint32_t id) __hidden;
 int __thr_umutex_timedlock(struct umutex *mtx, uint32_t id,
 	const struct timespec *timeout) __hidden;
-int __thr_umutex_unlock(struct umutex *mtx, uint32_t id) __hidden;
+int __thr_umutex_unlock(struct umutex *mtx) __hidden;
 int __thr_umutex_trylock(struct umutex *mtx) __hidden;
 int __thr_umutex_set_ceiling(struct umutex *mtx, uint32_t ceiling,
 	uint32_t *oldceiling) __hidden;
@@ -155,7 +155,7 @@ _thr_umutex_unlock2(struct umutex *mtx, uint32_t id, int *defer)
 		if (atomic_cmpset_rel_32(&mtx->m_owner, id, noncst ?
 		    UMUTEX_RB_NOTRECOV : UMUTEX_UNOWNED))
 			return (0);
-		return (__thr_umutex_unlock(mtx, id));
+		return (__thr_umutex_unlock(mtx));
 	}
 
 	do {