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b168057a | 1 | /* Copyright (C) 2003-2015 Free Software Foundation, Inc. |
b398ae3c UD |
2 | This file is part of the GNU C Library. |
3 | ||
4 | The GNU C Library is free software; you can redistribute it and/or | |
5 | modify it under the terms of the GNU Lesser General Public | |
6 | License as published by the Free Software Foundation; either | |
7 | version 2.1 of the License, or (at your option) any later version. | |
8 | ||
9 | The GNU C Library is distributed in the hope that it will be useful, | |
10 | but WITHOUT ANY WARRANTY; without even the implied warranty of | |
11 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU | |
12 | Lesser General Public License for more details. | |
13 | ||
14 | You should have received a copy of the GNU Lesser General Public | |
59ba27a6 PE |
15 | License along with the GNU C Library; if not, see |
16 | <http://www.gnu.org/licenses/>. */ | |
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17 | |
18 | #include <sysdep.h> | |
19 | #define _ERRNO_H 1 | |
20 | #include <bits/errno.h> | |
3d1024e8 | 21 | #include <tcb-offsets.h> |
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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) | |
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29 | |
30 | /* Load the TCB-cached PID value and negates it. If It it is zero | |
31 | sets it to 0x800000. And then sets its value again on TCB field. | |
32 | See raise.c for the logic that relies on this value. */ | |
33 | ||
34 | lwz r0,PID(r2) | |
35 | cmpwi cr0,r0,0 | |
36 | neg r0,r0 | |
37 | bne- cr0,1f | |
38 | lis r0,0x8000 | |
39 | 1: stw r0,PID(r2) | |
40 | ||
b398ae3c | 41 | DO_CALL (SYS_ify (vfork)) |
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42 | |
43 | cmpwi cr1,r3,0 | |
44 | beqlr- 1 | |
45 | ||
46 | /* Restore the original value of the TCB cache of the PID, if we're | |
47 | the parent. But in the child (syscall return value equals zero), | |
48 | leave things as they are. */ | |
49 | lwz r0,PID(r2) | |
50 | /* Cannot use clrlwi. here, because cr0 needs to be preserved | |
51 | until PSEUDO_RET. */ | |
52 | clrlwi r4,r0,1 | |
53 | cmpwi cr1,r4,0 | |
54 | beq- cr1,1f | |
55 | neg r4,r0 | |
56 | 1: stw r4,PID(r2) | |
57 | ||
b398ae3c | 58 | PSEUDO_RET |
3d1024e8 | 59 | |
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60 | PSEUDO_END (__vfork) |
61 | libc_hidden_def (__vfork) | |
62 | ||
63 | weak_alias (__vfork, vfork) | |
3d1024e8 | 64 | strong_alias (__vfork, __libc_vfork) |