platform_bionic/libc/arch-x86_64/bionic/__bionic_clone.S
Elliott Hughes 072ff571d9 Use L() in libc/arch-x86_64/bionic/*.S.
I did look at a wider cleanup of libc/arch-x86_64/string/*.S but was
horrified by what I found there, with apparently-useless macros that
may actually be relevant because source files include each other. So
I'll leave the Intel-written stuff alone until/unless I actually have
reason to touch it, and just clean up our corner instead.

Test: treehugger
Change-Id: Id749f79d2fab4a2956efe9e807a067e16cd606ec
2023-08-07 09:34:06 -07:00

76 lines
2.8 KiB
ArmAsm

/*
* Copyright (C) 2013 The Android Open Source Project
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* * Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* * 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 COPYRIGHT HOLDERS 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
* COPYRIGHT OWNER 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 <private/bionic_asm.h>
// pid_t __bionic_clone(int flags, void* child_stack, pid_t* parent_tid, void* tls, pid_t* child_tid, int (*fn)(void*), void* arg);
ENTRY_PRIVATE(__bionic_clone)
# Copy 'fn' and 'arg' onto the child stack.
movq %r9, -16(%rsi) # fn
movq 8(%rsp), %rax # Read 'arg'.
movq %rax, -8(%rsi) # Write 'arg'.
subq $16, %rsi
# Translate to the kernel calling convention and swap the 'tls' and 'child_tid' arguments.
# They're flipped for x86-64 compared to all our other architectures and __bionic_clone.
movq %r8, %r10
movq %rcx, %r8
# Make the system call.
movl $__NR_clone, %eax
syscall
# Check result.
testq %rax, %rax
jz L(bc_child)
jg L(bc_parent)
# An error occurred, set errno and return -1.
negl %eax
movl %eax, %edi
call __set_errno_internal
ret
L(bc_child):
# We don't want anyone to unwind past this point.
.cfi_undefined %rip
.cfi_undefined %rbp
# We're in the child now, so call __start_thread
# with the arguments from the child stack moved into
# the appropriate registers.
popq %rdi # fn
popq %rsi # arg
call __start_thread
hlt
L(bc_parent):
# We're the parent; nothing to do.
ret
END(__bionic_clone)