projects / thirdparty / glibc.git / blame
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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 | |
| 3214b89b AJ |
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 |
| ab84e3ff PE |
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) | |
| 5675da1e RM |
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 | ||
| 73886008 UW |
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 | |
| 5675da1e RM |
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) |