Add rfork_thread(3).

svn path=/head/; revision=121074

lib/libc/amd64/gen/Makefile.inc

@@ -1,7 +1,7 @@
 #	@(#)Makefile.inc	8.1 (Berkeley) 6/4/93
 # $FreeBSD$
 
-SRCS+=	_setjmp.S setjmp.S sigsetjmp.S \
+SRCS+=	_setjmp.S rfork_thread.S setjmp.S sigsetjmp.S \
 	fabs.S modf.S \
 	frexp.c infinity.c isinf.c ldexp.c \
 	makecontext.c signalcontext.c \

lib/libc/amd64/gen/rfork_thread.S

@@ -0,0 +1,101 @@
+/*-
+ * Copyright (c) 2000 Peter Wemm <peter@FreeBSD.org>
+ * Copyright (c) 2003 Alan L. Cox <alc@cs.rice.edu>
+ * All rights reserved.
+ *
+ * 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 <machine/asm.h>
+__FBSDID("$FreeBSD$");
+
+/*
+ * With thanks to John Dyson for the original version of this.
+ */
+
+#include <SYS.h>
+
+/*
+ *              %edi   %rsi        %rdx       %rcx
+ * rfork_thread(flags, stack_addr, start_fnc, start_arg);
+ *
+ * flags:		Flags to rfork system call.  See rfork(2).
+ * stack_addr:		Top of stack for thread.
+ * start_fnc:		Address of thread function to call in child.
+ * start_arg:		Argument to pass to the thread function in child.
+ */
+
+ENTRY(rfork_thread)
+	pushq	%rbx
+	pushq	%r12
+	movq	%rdx, %rbx
+	movq	%rcx, %r12
+
+	/*
+	 * Prepare and execute the thread creation syscall
+	 */
+	movq	$SYS_rfork, %rax
+	KERNCALL
+	jb 	2f
+
+	/*
+	 * Check to see if we are in the parent or child
+	 */
+	cmpl	$0, %edx
+	jnz	1f
+	popq	%r12
+	popq	%rbx
+	ret
+
+	/*
+	 * If we are in the child (new thread), then
+	 * set-up the call to the internal subroutine.  If it
+	 * returns, then call __exit.
+	 */
+1:
+	movq	%rsi, %rsp
+	movq	%r12, %rdi 
+	call	*%rbx
+	movl	%eax, %edi
+
+	/*
+	 * Exit system call
+	 */
+#ifdef SYS_exit
+	movq	$SYS_exit, %rax
+#else
+	movq	$SYS_sys_exit, %rax
+#endif
+	KERNCALL
+
+	/*
+	 * Branch here if the thread creation fails:
+	 */
+2:
+	popq	%r12
+	popq	%rbx
+#ifdef PIC
+	movq	PIC_GOT(HIDENAME(cerror)), %rdx
+	jmp	*%rdx
+#else
+	jmp	HIDENAME(cerror)
+#endif