libthr: Preresolve selected EABI symbols on arm.

Add the ability to pre-resolve architecture-specific EABI symbols and
use it on arm for selected EABI functions. These functions can be called
with rtld bind lock write-locked, so they should be resolved in forward.

Reported by:	Mark Millard <marklmi@yahoo.com>, John F Carr <jfc@mit.edu>
Reviewed by:	kib, imp
MFC after:	1 week
Differential Revision:  https://reviews.freebsd.org/D46104

(cherry picked from commit 5670b8cc36)

lib/libthr/arch/aarch64/include/pthread_md.h

@@ -49,4 +49,9 @@ _get_curthread(void)
 	return (_tcb_get()->tcb_thread);
 }
 
+static __inline void
+_thr_resolve_machdep(void)
+{
+}
+
 #endif /* _PTHREAD_MD_H_ */

lib/libthr/arch/amd64/include/pthread_md.h

@@ -54,4 +54,9 @@ _get_curthread(void)
 
 #define	HAS__UMTX_OP_ERR	1
 
+static __inline void
+_thr_resolve_machdep(void)
+{
+}
+
 #endif

lib/libthr/arch/arm/Makefile.inc

@@ -0,0 +1,3 @@
+.PATH: ${.CURDIR}/arch/arm
+SRCS+= \
+ thr_rtld_arm.c

lib/libthr/arch/arm/thr_rtld_arm.c

@@ -0,0 +1,67 @@
+/*-
+ * SPDX-License-Identifier: BSD-2-Clause
+ *
+ * Copyright (c) 2024, Michal Meloun <mmel@freebsd.org>
+ *
+ * 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 unmodified, 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 ``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 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 <stdlib.h>
+#include <string.h>
+
+#include "thr_private.h"
+
+int __aeabi_idiv(int , int );
+unsigned __aeabi_uidiv(unsigned, unsigned );
+
+struct {int q; int r;} __aeabi_idivmod(int, int );
+struct {unsigned q; unsigned r;} __aeabi_uidivmod(unsigned, unsigned);
+
+struct {int64_t q; int64_t r;} __aeabi_ldivmod(int64_t, int64_t);
+struct {uint64_t q; uint64_t r;} __aeabi_uldivmod(uint64_t, uint64_t);
+
+void __aeabi_memset(void *dest, size_t n, int c);
+void __aeabi_memclr(void *dest, size_t n);
+void __aeabi_memmove(void *dest, void *src, size_t n);
+void __aeabi_memcpy(void *dest, void *src, size_t n);
+void __aeabi_memcmp(void *dest, void *src, size_t n);
+
+void
+_thr_resolve_machdep(void)
+{
+	char tmp[2];
+
+	__aeabi_idiv(1, 1);
+	__aeabi_uidiv(1, 1);
+
+	__aeabi_idivmod(1, 1);
+	__aeabi_uidivmod(1, 1);
+
+	__aeabi_ldivmod(1, 1);
+	__aeabi_uldivmod(1, 1);
+
+	__aeabi_memset(tmp, 1, 0);
+	__aeabi_memclr(tmp, 1);
+	__aeabi_memmove(tmp, tmp + 1, 1);
+	__aeabi_memcpy(tmp, tmp + 1, 1);
+	__aeabi_memcmp(tmp, tmp + 1, 1);
+}

lib/libthr/arch/i386/include/pthread_md.h

@@ -54,4 +54,9 @@ _get_curthread(void)
 
 #define HAS__UMTX_OP_ERR	1
 
+static __inline void
+_thr_resolve_machdep(void)
+{
+}
+
 #endif

lib/libthr/arch/mips/include/pthread_md.h

@@ -50,4 +50,9 @@ _get_curthread(void)
 	return (NULL);
 }
 
+static __inline void
+_thr_resolve_machdep(void)
+{
+}
+
 #endif /* _PTHREAD_MD_H_ */

lib/libthr/arch/powerpc/include/pthread_md.h

@@ -51,4 +51,9 @@ _get_curthread(void)
 
 #define	HAS__UMTX_OP_ERR	1
 
+static __inline void
+_thr_resolve_machdep(void)
+{
+}
+
 #endif /* _PTHREAD_MD_H_ */

lib/libthr/arch/riscv/include/pthread_md.h

@@ -56,4 +56,9 @@ _get_curthread(void)
 	return (NULL);
 }
 
+static __inline void
+_thr_resolve_machdep(void)
+{
+}
+
 #endif /* _PTHREAD_MD_H_ */

lib/libthr/thread/thr_private.h

@@ -1102,6 +1102,7 @@ int __Tthr_mutex_lock(pthread_mutex_t *);
 int __Tthr_mutex_trylock(pthread_mutex_t *);
 bool __thr_get_main_stack_base(char **base);
 bool __thr_get_main_stack_lim(size_t *lim);
+void _thr_resolve_machdep(void);
 
 __END_DECLS
 __NULLABILITY_PRAGMA_POP

lib/libthr/thread/thr_rtld.c

@@ -275,6 +275,9 @@ _thr_rtld_init(void)
 	_thr_signal_block_check_fast();
 	_thr_signal_block_setup(curthread);
 
+	/* resolve machine depended functions, if any */
+	_thr_resolve_machdep();
+
 	uc_len = __getcontextx_size();
 	uc = alloca(uc_len);
 	getcontext(uc);