Untangle jemalloc and mutexes initialization.

The need to use libc malloc(3) from some places in libthr always
caused issues.  For instance, per-thread key allocation was switched to
use plain mmap(2) to get storage, because some third party mallocs
used keys for implementation of calloc(3).

Even more important, libthr calls calloc(3) during initialization of
pthread mutexes, and jemalloc uses pthread mutexes.  Jemalloc provides
some way to both postpone the initialization, and to make
initialization to use specialized allocator, but this is very fragile
and often breaks.  See the referenced PR for another example.

Add the small malloc implementation used by rtld, to libthr. Use it in
thr_spec.c and for mutexes initialization. This avoids the issues with
mutual dependencies between malloc and libthr in principle.  The
drawback is that some more allocations are not interceptable for
alternate malloc implementations.  There should be not too much memory
use from this allocator, and the alternative, direct use of mmap(2) is
obviously worse.

PR:	235211
MFC after:	2 weeks
Sponsored by:	The FreeBSD Foundation
Differential revision:	https://reviews.freebsd.org/D18988

lib/libthr/Makefile

@@ -27,6 +27,7 @@ CFLAGS+=-I${SRCTOP}/lib/libthread_db
 CFLAGS+=-Winline
 
 CFLAGS.thr_stack.c+=	-Wno-cast-align
+CFLAGS.malloc.c+=	-Wno-cast-align
 .include <bsd.compiler.mk>
 .if !(${COMPILER_TYPE} == "gcc" && ${COMPILER_VERSION} < 40300)
 CFLAGS.thr_symbols.c+=	-Wno-missing-variable-declarations
@@ -50,12 +51,14 @@ CFLAGS+=-D_PTHREADS_INVARIANTS
 PRECIOUSLIB=
 
 .PATH: ${.CURDIR}/arch/${MACHINE_CPUARCH}/${MACHINE_CPUARCH}
+.PATH: ${SRCTOP}/libexec/rtld-elf
 
 .if exists(${.CURDIR}/arch/${MACHINE_CPUARCH}/Makefile.inc)
 .include "${.CURDIR}/arch/${MACHINE_CPUARCH}/Makefile.inc"
 .endif
 .include "${.CURDIR}/sys/Makefile.inc"
 .include "${.CURDIR}/thread/Makefile.inc"
+SRCS+= malloc.c
 
 .if ${MK_INSTALLLIB} != "no"
 SYMLINKS+=lib${LIB}.a ${LIBDIR}/libpthread.a

lib/libthr/thread/Makefile.inc

@@ -31,6 +31,7 @@ SRCS+= \
 	thr_kern.c \
 	thr_kill.c \
 	thr_main_np.c \
+	thr_malloc.c \
 	thr_multi_np.c \
 	thr_mutex.c \
 	thr_mutexattr.c \

lib/libthr/thread/thr_fork.c

@@ -170,6 +170,7 @@ __thr_fork(void)
 	 */
 	if (_thr_isthreaded() != 0) {
 		was_threaded = 1;
+		__thr_malloc_prefork(curthread);
 		_malloc_prefork();
 		__thr_pshared_atfork_pre();
 		_rtld_atfork_pre(rtld_locks);
@@ -197,6 +198,10 @@ __thr_fork(void)
 		 */
 		curthread->tlflags &= ~TLFLAGS_IN_TDLIST;
 
+		/* before thr_self() */
+		if (was_threaded)
+			__thr_malloc_postfork(curthread);
+
 		/* child is a new kernel thread. */
 		thr_self(&curthread->tid);
 
@@ -241,6 +246,7 @@ __thr_fork(void)
 		_thr_signal_postfork();
 
 		if (was_threaded) {
+			__thr_malloc_postfork(curthread);
 			_rtld_atfork_post(rtld_locks);
 			__thr_pshared_atfork_post();
 			_malloc_postfork();

lib/libthr/thread/thr_init.c

@@ -461,6 +461,7 @@ init_private(void)
 	 */
 	if (init_once == 0) {
 		__thr_pshared_init();
+		__thr_malloc_init();
 		/* Find the stack top */
 		mib[0] = CTL_KERN;
 		mib[1] = KERN_USRSTACK;

lib/libthr/thread/thr_malloc.c

@@ -0,0 +1,137 @@
+/*-
+ * SPDX-License-Identifier: BSD-2-Clause-FreeBSD
+ *
+ * Copyright (c) 2019 The FreeBSD Foundation
+ * All rights reserved.
+ *
+ * This software was developed by Konstantin Belousov <kib@FreeBSD.org>
+ * under sponsorship from the FreeBSD Foundation.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+ * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ */
+
+#include <sys/cdefs.h>
+__FBSDID("$FreeBSD$");
+
+#include <sys/types.h>
+#include <sys/mman.h>
+#include <rtld_malloc.h>
+#include "thr_private.h"
+
+int npagesizes;
+size_t *pagesizes;
+static size_t pagesizes_d[2];
+static struct umutex thr_malloc_umtx;
+
+void
+__thr_malloc_init(void)
+{
+
+	npagesizes = getpagesizes(pagesizes_d, nitems(pagesizes_d));
+	if (npagesizes == -1) {
+		npagesizes = 1;
+		pagesizes_d[0] = PAGE_SIZE;
+	}
+	pagesizes = pagesizes_d;
+	_thr_umutex_init(&thr_malloc_umtx);
+}
+
+static void
+thr_malloc_lock(struct pthread *curthread)
+{
+
+	curthread->locklevel++;
+	_thr_umutex_lock(&thr_malloc_umtx, TID(curthread));
+}
+
+static void
+thr_malloc_unlock(struct pthread *curthread)
+{
+
+	_thr_umutex_unlock(&thr_malloc_umtx, TID(curthread));
+	curthread->locklevel--;
+	_thr_ast(curthread);
+}
+
+void *
+__thr_calloc(size_t num, size_t size)
+{
+	struct pthread *curthread;
+	void *res;
+
+	curthread = _get_curthread();
+	thr_malloc_lock(curthread);
+	res = __crt_calloc(num, size);
+	thr_malloc_unlock(curthread);
+	return (res);
+}
+
+void
+__thr_free(void *cp)
+{
+	struct pthread *curthread;
+
+	curthread = _get_curthread();
+	thr_malloc_lock(curthread);
+	__crt_free(cp);
+	thr_malloc_unlock(curthread);
+}
+
+void *
+__thr_malloc(size_t nbytes)
+{
+	struct pthread *curthread;
+	void *res;
+
+	curthread = _get_curthread();
+	thr_malloc_lock(curthread);
+	res = __crt_malloc(nbytes);
+	thr_malloc_unlock(curthread);
+	return (res);
+}
+
+void *
+__thr_realloc(void *cp, size_t nbytes)
+{
+	struct pthread *curthread;
+	void *res;
+
+	curthread = _get_curthread();
+	thr_malloc_lock(curthread);
+	res = __crt_realloc(cp, nbytes);
+	thr_malloc_unlock(curthread);
+	return (res);
+}
+
+void
+__thr_malloc_prefork(struct pthread *curthread)
+{
+
+	_thr_umutex_lock(&thr_malloc_umtx, TID(curthread));
+}
+
+void
+__thr_malloc_postfork(struct pthread *curthread)
+{
+
+	_thr_umutex_unlock(&thr_malloc_umtx, TID(curthread));
+}

lib/libthr/thread/thr_mutex.c

@@ -306,10 +306,11 @@ init_static(struct pthread *thread, pthread_mutex_t *mutex)
 	THR_LOCK_ACQUIRE(thread, &_mutex_static_lock);
 
 	if (*mutex == THR_MUTEX_INITIALIZER)
-		ret = mutex_init(mutex, &_pthread_mutexattr_default, calloc);
+		ret = mutex_init(mutex, &_pthread_mutexattr_default,
+		    __thr_calloc);
 	else if (*mutex == THR_ADAPTIVE_MUTEX_INITIALIZER)
 		ret = mutex_init(mutex, &_pthread_mutexattr_adaptive_default,
-		    calloc);
+		    __thr_calloc);
 	else
 		ret = 0;
 	THR_LOCK_RELEASE(thread, &_mutex_static_lock);
@@ -390,7 +391,7 @@ __pthread_mutex_init(pthread_mutex_t * __restrict mutex,
 	if (mutex_attr == NULL ||
 	    (*mutex_attr)->m_pshared == PTHREAD_PROCESS_PRIVATE) {
 		return (mutex_init(mutex, mutex_attr ? *mutex_attr : NULL,
-		    calloc));
+		    __thr_calloc));
 	}
 	pmtx = __thr_pshared_offpage(__DECONST(void *, mutex), 1);
 	if (pmtx == NULL)
@@ -483,7 +484,7 @@ _pthread_mutex_destroy(pthread_mutex_t *mutex)
 		} else {
 			*mutex = THR_MUTEX_DESTROYED;
 			mutex_assert_not_owned(_get_curthread(), m);
-			free(m);
+			__thr_free(m);
 			ret = 0;
 		}
 	}

lib/libthr/thread/thr_private.h

@@ -1003,6 +1003,14 @@ void __thr_pshared_destroy(void *key) __hidden;
 void __thr_pshared_atfork_pre(void) __hidden;
 void __thr_pshared_atfork_post(void) __hidden;
 
+void *__thr_calloc(size_t num, size_t size);
+void __thr_free(void *cp);
+void *__thr_malloc(size_t nbytes);
+void *__thr_realloc(void *cp, size_t nbytes);
+void __thr_malloc_init(void);
+void __thr_malloc_prefork(struct pthread *curthread);
+void __thr_malloc_postfork(struct pthread *curthread);
+
 __END_DECLS
 __NULLABILITY_PRAGMA_POP
 

lib/libthr/thread/thr_spec.c

@@ -155,8 +155,7 @@ _thread_cleanupspecific(void)
 		}
 	}
 	THR_LOCK_RELEASE(curthread, &_keytable_lock);
-	munmap(curthread->specific, PTHREAD_KEYS_MAX * sizeof(struct
-	    pthread_specific_elem));
+	__thr_free(curthread->specific);
 	curthread->specific = NULL;
 	if (curthread->specific_data_count > 0) {
 		stderr_debug("Thread %p has exited with leftover "
@@ -179,10 +178,9 @@ _pthread_setspecific(pthread_key_t userkey, const void *value)
 
 	pthread = _get_curthread();
 	if (pthread->specific == NULL) {
-		tmp = mmap(NULL, PTHREAD_KEYS_MAX *
-		    sizeof(struct pthread_specific_elem),
-		    PROT_READ | PROT_WRITE, MAP_PRIVATE | MAP_ANON, -1, 0);
-		if (tmp == MAP_FAILED)
+		tmp = __thr_calloc(PTHREAD_KEYS_MAX,
+		    sizeof(struct pthread_specific_elem));
+		if (tmp == NULL)
 			return (ENOMEM);
 		pthread->specific = tmp;
 	}