linux: Add ptrace(2) support on arm64

This moves linux_ptrace.c from sys/amd64/linux/ to sys/compat/linux/,
making it possible to use it on architectures other than amd64.
It also enables Linux ptrace(2) on arm64.

Relnotes:	yes
Sponsored By:	EPSRC
Differential Revision:	https://reviews.freebsd.org/D32868

sys/arm64/linux/linux_ptrace.c

@@ -1,56 +0,0 @@
-/*-
- * SPDX-License-Identifier: BSD-2-Clause-FreeBSD
- *
- * Copyright (C) 2018 Turing Robotic Industries Inc.
- *
- * 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.
- *
- * $FreeBSD$
- */
-
-#include <sys/cdefs.h>
-__FBSDID("$FreeBSD$");
-
-#include <sys/param.h>
-#include <sys/kernel.h>
-#include <sys/sdt.h>
-#include <sys/proc.h>
-#include <sys/ptrace.h>
-
-#include <arm64/linux/linux.h>
-#include <arm64/linux/linux_proto.h>
-#include <compat/linux/linux_dtrace.h>
-
-/* DTrace init */
-LIN_SDT_PROVIDER_DECLARE(LINUX_DTRACE);
-
-/* DTrace probes */
-LIN_SDT_PROBE_DEFINE0(ptrace, linux_ptrace, todo);
-
-int
-linux_ptrace(struct thread *td, struct linux_ptrace_args *uap)
-{
-
-	/* LINUXTODO: implement arm64 linux_ptrace */
-	LIN_SDT_PROBE0(ptrace, linux_ptrace, todo);
-	return (EDOOFUS);
-}

sys/compat/linux/linux_misc.c

@@ -1024,7 +1024,7 @@ linux_common_wait(struct thread *td, int pid, int *statusp,
 		} else if (WIFSTOPPED(tmpstat)) {
 			tmpstat = (tmpstat & 0xffff00ff) |
 			    (bsd_to_linux_signal(WSTOPSIG(tmpstat)) << 8);
-#if defined(__amd64__) && !defined(COMPAT_LINUX32)
+#if defined(__aarch64__) || (defined(__amd64__) && !defined(COMPAT_LINUX32))
 			if (WSTOPSIG(status) == SIGTRAP) {
 				tmpstat = linux_ptrace_status(td,
 				    siginfo.si_pid, tmpstat);

sys/compat/linux/linux_misc.h

@@ -153,7 +153,7 @@ extern int stclohz;
 /* Linux syslog flags */
 #define	LINUX_SYSLOG_ACTION_READ_ALL	3
 
-#if defined(__amd64__) && !defined(COMPAT_LINUX32)
+#if defined(__aarch64__) || (defined(__amd64__) && !defined(COMPAT_LINUX32))
 int linux_ptrace_status(struct thread *td, int pid, int status);
 #endif
 void linux_to_bsd_waitopts(int options, int *bsdopts);