| Elliott Hughes | ebc19a9 | 2022-10-14 23:25:36 +0000 | [diff] [blame] | 1 | /* |
| 2 | * Copyright (C) 2022 The Android Open Source Project |
| 3 | * All rights reserved. |
| 4 | * |
| 5 | * Redistribution and use in source and binary forms, with or without |
| 6 | * modification, are permitted provided that the following conditions |
| 7 | * are met: |
| 8 | * * Redistributions of source code must retain the above copyright |
| 9 | * notice, this list of conditions and the following disclaimer. |
| 10 | * * Redistributions in binary form must reproduce the above copyright |
| 11 | * notice, this list of conditions and the following disclaimer in |
| 12 | * the documentation and/or other materials provided with the |
| 13 | * distribution. |
| 14 | * |
| 15 | * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS |
| 16 | * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT |
| 17 | * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS |
| 18 | * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE |
| 19 | * COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, |
| 20 | * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, |
| 21 | * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS |
| 22 | * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED |
| 23 | * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, |
| 24 | * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT |
| 25 | * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF |
| 26 | * SUCH DAMAGE. |
| 27 | */ |
| 28 | |
| 29 | #include <private/bionic_asm.h> |
| 30 | |
| 31 | // pid_t __bionic_clone(int flags, void* child_stack, pid_t* parent_tid, void* tls, pid_t* child_tid, int (*fn)(void*), void* arg); |
| 32 | |
| 33 | ENTRY_PRIVATE(__bionic_clone) |
| 34 | # Push 'fn' and 'arg' onto the child stack. |
| 35 | addi a1, a1, -16 |
| 36 | sd a5, 0(a1) |
| Elliott Hughes | c800a3b | 2022-10-18 20:01:58 +0000 | [diff] [blame^] | 37 | sd a6, 8(a1) |
| Elliott Hughes | ebc19a9 | 2022-10-14 23:25:36 +0000 | [diff] [blame] | 38 | |
| 39 | # Make the system call. |
| 40 | li a7, __NR_clone |
| 41 | ecall |
| 42 | |
| 43 | # Are we the child? |
| 44 | beqz a0, .L_bc_child |
| 45 | |
| 46 | # Did the clone(2) fail? |
| 47 | bltz a0, .L_bc_failure |
| 48 | # Nope, we're the parent, and our work here is done. |
| 49 | ret |
| 50 | |
| 51 | .L_bc_failure: |
| 52 | # Set errno if something went wrong. |
| 53 | neg a0, a0 |
| 54 | j __set_errno_internal |
| 55 | |
| 56 | .L_bc_child: |
| 57 | # We're in the child now. Set the end of the frame record chain. |
| 58 | li fp, 0 |
| 59 | # Setting ra to 0 will make the unwinder stop at __start_thread. |
| 60 | li ra, 0 |
| 61 | # Call __start_thread with the 'fn' and 'arg' we stored on the child stack. |
| 62 | ld a0, 0(sp) |
| 63 | ld a1, 8(sp) |
| 64 | addi sp, sp, 16 |
| 65 | j __start_thread |
| 66 | END(__bionic_clone) |