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b168057a | 1 | /* Copyright (C) 1999-2015 Free Software Foundation, Inc. |
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2 | This file is part of the GNU C Library. |
3 | Contributed by Philip Blundell <philb@gnu.org>. | |
4 | ||
5 | The GNU C Library is free software; you can redistribute it and/or | |
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6 | modify it under the terms of the GNU Lesser General Public |
7 | License as published by the Free Software Foundation; either | |
8 | version 2.1 of the License, or (at your option) any later version. | |
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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 | |
3214b89b | 13 | Lesser General Public License for more details. |
74804c97 | 14 | |
3214b89b | 15 | You should have received a copy of the GNU Lesser General Public |
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16 | License along with the GNU C Library. If not, see |
17 | <http://www.gnu.org/licenses/>. */ | |
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18 | |
19 | #include <sysdep.h> | |
20 | #define _ERRNO_H 1 | |
21 | #include <bits/errno.h> | |
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22 | #include <tcb-offsets.h> |
23 | ||
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24 | |
25 | /* Clone the calling process, but without copying the whole address space. | |
26 | The calling process is suspended until the new process exits or is | |
27 | replaced by a call to `execve'. Return -1 for errors, 0 to the new process, | |
28 | and the process ID of the new process to the old process. */ | |
29 | ||
30 | ENTRY (__vfork) | |
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31 | /* Save the PID value. */ |
32 | GET_TLS (r2) | |
33 | NEGOFF_ADJ_BASE2 (r2, r0, PID_OFFSET) /* Save the TLS addr in r2. */ | |
34 | ldr r3, NEGOFF_OFF1 (r2, PID_OFFSET) /* Load the saved PID. */ | |
35 | rsbs r0, r3, #0 /* Negate it, and test for zero. */ | |
36 | /* Use 0x80000000 if it was 0. See raise.c for how this is used. */ | |
37 | it eq | |
38 | moveq r0, #0x80000000 | |
39 | str r0, NEGOFF_OFF1 (r2, PID_OFFSET) /* Store the temp PID. */ | |
40 | ||
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41 | /* The DO_CALL macro saves r7 on the stack, to enable generation |
42 | of ARM unwind info. Since the stack is initially shared between | |
43 | parent and child of vfork, that saved value could be corrupted. | |
44 | To avoid this problem, we save r7 into ip as well, and restore | |
45 | from there. */ | |
46 | mov ip, r7 | |
47 | cfi_register (r7, ip) | |
48 | .fnstart | |
55668624 | 49 | push { r7 } |
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50 | cfi_adjust_cfa_offset (4) |
51 | .save { r7 } | |
52 | ldr r7, =SYS_ify (vfork) | |
53 | swi 0x0 | |
54 | .fnend | |
55 | add sp, sp, #4 | |
56 | cfi_adjust_cfa_offset (-4) | |
57 | mov r7, ip | |
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58 | cfi_restore (r7) |
59 | ||
60 | /* Restore the old PID value in the parent. */ | |
61 | cmp r0, #0 /* If we are the parent... */ | |
62 | it ne | |
63 | strne r3, NEGOFF_OFF1 (r2, PID_OFFSET) /* restore the saved PID. */ | |
64 | ||
74804c97 | 65 | cmn a1, #4096 |
6ccd0107 | 66 | it cc |
47f0752a | 67 | RETINSTR(cc, lr) |
74804c97 | 68 | |
02a9f771 | 69 | b PLTJMP(SYSCALL_ERROR) |
74804c97 | 70 | PSEUDO_END (__vfork) |
db160231 | 71 | libc_hidden_def (__vfork) |
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72 | |
73 | weak_alias (__vfork, vfork) | |
5675da1e | 74 | strong_alias (__vfork, __libc_vfork) |