| /* |
| * 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 <platform/bionic/tls_defines.h> |
| #include <private/bionic_asm.h> |
| |
| // This custom code preserves the return address across the system call. |
| |
| ENTRY_WEAK_FOR_NATIVE_BRIDGE(vfork) |
| popq %rdi // Grab the return address. |
| |
| // Set cached_pid_ to 0, vforked_ to 1, and stash the previous value. |
| mov %fs:0, %r8 |
| mov (TLS_SLOT_THREAD_ID * 8)(%r8), %r8 |
| movl 20(%r8), %r9d |
| movl $0x80000000, 20(%r8) |
| |
| movl $__NR_vfork, %eax |
| syscall |
| pushq %rdi // Restore the return address. |
| |
| test %eax, %eax |
| jz 1f |
| |
| // rc != 0: restore the previous cached_pid_/vforked_ values. |
| movl %r9d, 20(%r8) |
| |
| cmpq $-MAX_ERRNO, %rax |
| jb 1f |
| negl %eax |
| movl %eax, %edi |
| call __set_errno_internal |
| 1: |
| ret |
| END(vfork) |
