| 1 | /* Copyright (C) 1999-2024 Free Software Foundation, Inc. |
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| 2 | This file is part of the GNU C Library. |
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| 3 | |
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| 4 | The GNU C Library is free software; you can redistribute it and/or |
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| 5 | modify it under the terms of the GNU Lesser General Public |
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| 6 | License as published by the Free Software Foundation; either |
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| 7 | version 2.1 of the License, or (at your option) any later version. |
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| 8 | |
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| 9 | The GNU C Library is distributed in the hope that it will be useful, |
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| 10 | but WITHOUT ANY WARRANTY; without even the implied warranty of |
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| 11 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU |
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| 12 | Lesser General Public License for more details. |
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| 13 | |
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| 14 | You should have received a copy of the GNU Lesser General Public |
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| 15 | License along with the GNU C Library; if not, see |
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| 16 | <https://www.gnu.org/licenses/>. */ |
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| 17 | |
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| 18 | #include <sysdep.h> |
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| 19 | #define _ERRNO_H 1 |
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| 20 | #include <bits/errno.h> |
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| 21 | #include <tcb-offsets.h> |
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| 22 | |
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| 23 | |
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| 24 | /* Clone the calling process, but without copying the whole address space. |
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| 25 | The calling process is suspended until the new process exits or is |
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| 26 | replaced by a call to `execve'. Return -1 for errors, 0 to the new process, |
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| 27 | and the process ID of the new process to the old process. */ |
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| 28 | |
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| 29 | ENTRY (__vfork) |
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| 30 | |
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| 31 | /* Pop the return PC value into ECX. */ |
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| 32 | popl %ecx |
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| 33 | cfi_adjust_cfa_offset (-4) |
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| 34 | cfi_register (%eip, %ecx) |
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| 35 | |
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| 36 | /* Stuff the syscall number in EAX and enter into the kernel. */ |
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| 37 | movl $SYS_ify (vfork), %eax |
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| 38 | int $0x80 |
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| 39 | |
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| 40 | /* Jump to the return PC. Don't jump directly since this |
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| 41 | disturbs the branch target cache. Instead push the return |
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| 42 | address back on the stack. */ |
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| 43 | pushl %ecx |
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| 44 | cfi_adjust_cfa_offset (4) |
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| 45 | |
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| 46 | cmpl $-4095, %eax |
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| 47 | /* Branch forward if it failed. */ |
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| 48 | jae SYSCALL_ERROR_LABEL |
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| 49 | |
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| 50 | ret |
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| 51 | |
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| 52 | PSEUDO_END (__vfork) |
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| 53 | libc_hidden_def (__vfork) |
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| 54 | |
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| 55 | weak_alias (__vfork, vfork) |
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| 56 | strong_alias (__vfork, __libc_vfork) |
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| 57 | |
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