diff options
Diffstat (limited to 'lib/libc/amd64/gen/rfork_thread.S')
| -rw-r--r-- | lib/libc/amd64/gen/rfork_thread.S | 99 |
1 files changed, 99 insertions, 0 deletions
diff --git a/lib/libc/amd64/gen/rfork_thread.S b/lib/libc/amd64/gen/rfork_thread.S new file mode 100644 index 000000000000..5e764db831f5 --- /dev/null +++ b/lib/libc/amd64/gen/rfork_thread.S @@ -0,0 +1,99 @@ +/*- + * 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 + jmp HIDENAME(cerror) +END(rfork_thread) + + .section .note.GNU-stack,"",%progbits |