| /* |
| * Copyright (C) 2020 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> |
| #include <asm/signal.h> |
| #include <linux/sched.h> |
| |
| ENTRY(vfork) |
| // t0 = __get_tls()[TLS_SLOT_THREAD_ID] |
| mv t0, tp |
| ld t0, TLS_SLOT_THREAD_ID * 8(t0) |
| |
| // Set cached_pid_ to 0, vforked_ to 1, and stash the previous value. |
| li t1, 0x80000000 |
| lw t2, 20(t0) |
| sw t1, 20(t0) |
| |
| li a0, (CLONE_VM | CLONE_VFORK | SIGCHLD) |
| li a1, 0 //uses a duplicate of the parent's stack |
| li a2, 0 |
| li a3, 0 |
| li a4, 0 |
| |
| li a7, __NR_clone |
| ecall |
| |
| // if (rc == 0) we're the child, and finished... |
| beqz a0, .L_success |
| |
| // else if (rc != 0): reset cached_pid_ and vforked_... |
| sw t2, 20(t0) |
| // ...and work out whether we succeeded or failed. |
| bltz a0, .L_failure |
| .L_success: |
| ret |
| |
| .L_failure: |
| neg a0, a0 |
| tail __set_errno_internal |
| END(vfork) |