mach: Add __mach_setup_thread_call ()

This is just like mach_setup_thread (), but it's suitable for making the
thread call a function correctly, as opposed to explicitly setting the
thread's stack and instruction pointers to the given values. Internally,
it uses MACHINE_THREAD_STATE_SETUP_CALL.

Unlike mach_setup_thread (), which is exported via mach.h for the
benefit of the Hurd exec server, __mach_setup_thread_call () is private
to glibc for the time being.

Signed-off-by: Sergey Bugaev <bugaevc@gmail.com>
Message-Id: <20230517191436.73636-5-bugaevc@gmail.com>

1 files changed, 32 insertions, 0 deletions

diff --git a/mach/setup-thread.h b/mach/setup-thread.h
new file mode 100644
index 0000000000..b4c94d1d5b
--- /dev/null
+++ b/mach/setup-thread.h
@@ -0,0 +1,32 @@
+/* Setup a Mach thread.
+   Copyright (C) 1993-2023 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+
+   The GNU C Library is free software; you can redistribute it and/or
+   modify it under the terms of the GNU Lesser General Public
+   License as published by the Free Software Foundation; either
+   version 2.1 of the License, or (at your option) any later version.
+
+   The GNU C Library is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+   Lesser General Public License for more details.
+
+   You should have received a copy of the GNU Lesser General Public
+   License along with the GNU C Library; if not, see
+   <https://www.gnu.org/licenses/>.  */
+
+#ifndef	_MACH_SETUP_THREAD_H
+
+#define	_MACH_SETUP_THREAD_H	1
+
+#include <mach.h>
+
+/* Like mach_setup_thread (), but suitable for setting up function
+   calls.  */
+kern_return_t __mach_setup_thread_call (task_t task, thread_t thread,
+					void *function,
+					vm_address_t *stack_base,
+					vm_size_t *stack_size);
+
+#endif	/* mach/setup-thread.h */