projects / thirdparty / glibc.git / blame
| Commit | Line | Data |
|---|---|---|
| b168057a | 1 | /* Copyright (C) 1999-2015 Free Software Foundation, Inc. |
| 554066b8 MS |
2 | |
| 3 | This file is part of the GNU C Library. | |
| 4 | ||
| 5 | The GNU C Library is free software; you can redistribute it and/or | |
| 6 | modify it under the terms of the GNU Lesser General Public License as | |
| 7 | published by the Free Software Foundation; either version 2.1 of the | |
| 8 | License, or (at your option) any later version. | |
| 9 | ||
| 10 | The GNU C Library is distributed in the hope that it will be useful, | |
| 11 | but WITHOUT ANY WARRANTY; without even the implied warranty of | |
| 12 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU | |
| 13 | Lesser General Public License for more details. | |
| 14 | ||
| 15 | You should have received a copy of the GNU Lesser General Public | |
| 16 | License along with the GNU C Library; if not, see | |
| 17 | <http://www.gnu.org/licenses/>. */ | |
| 18 | ||
| 19 | #include <sysdep.h> | |
| 20 | #define _ERRNO_H 1 | |
| 21 | #include <bits/errno.h> | |
| 554066b8 MS |
22 | |
| 23 | /* Clone the calling process, but without copying the whole address space. | |
| 24 | The calling process is suspended until the new process exits or is | |
| 25 | replaced by a call to `execve'. Return -1 for errors, 0 to the new process, | |
| 26 | and the process ID of the new process to the old process. */ | |
| 27 | ||
| 28 | ENTRY (__vfork) | |
| 29 | ||
| 89b4bd6b RH |
30 | /* Save the TCB-cached PID away in w3, and then negate the TCB |
| 31 | field. But if it's zero, set it to 0x80000000 instead. See | |
| 32 | raise.c for the logic that relies on this value. */ | |
| 33 | mrs x2, tpidr_el0 | |
| 34 | sub x2, x2, #PTHREAD_SIZEOF | |
| 35 | ldr w3, [x2, #PTHREAD_PID_OFFSET] | |
| 36 | mov w1, #0x80000000 | |
| 37 | negs w0, w3 | |
| 38 | csel w0, w1, w0, eq | |
| 39 | str w0, [x2, #PTHREAD_PID_OFFSET] | |
| 40 | ||
| 554066b8 MS |
41 | mov x0, #0x4111 /* CLONE_VM | CLONE_VFORK | SIGCHLD */ |
| 42 | mov x1, sp | |
| 43 | DO_CALL (clone, 2) | |
| 89b4bd6b RH |
44 | |
| 45 | /* Restore the original value of the TCB cache of the PID, if we're | |
| 46 | the parent. But in the child (syscall return value equals zero), | |
| 47 | leave things as they are. */ | |
| 48 | cbz x0, 1f | |
| 49 | str w3, [x2, #PTHREAD_PID_OFFSET] | |
| 50 | 1: | |
| 554066b8 | 51 | cmn x0, #4095 |
| 89b4bd6b | 52 | b.cs .Lsyscall_error |
| 554066b8 | 53 | RET |
| 554066b8 MS |
54 | |
| 55 | PSEUDO_END (__vfork) | |
| 56 | libc_hidden_def (__vfork) | |
| 57 | ||
| 58 | weak_alias (__vfork, vfork) | |
| 89b4bd6b | 59 | strong_alias (__vfork, __libc_vfork) |