| 1 | /* Copyright (C) 1999-2022 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 | /* clone() is even more special than fork() as it mucks with stacks |
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| 19 | and invokes a function in the right context after its all over. */ |
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| 20 | |
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| 21 | #include <sysdep.h> |
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| 22 | #define _ERRNO_H 1 |
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| 23 | #include <bits/errno.h> |
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| 24 | #include <tcb-offsets.h> |
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| 25 | |
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| 26 | /* int clone(int (*fn)(void *arg), void *child_stack, int flags, void *arg, |
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| 27 | pid_t *ptid, void *tls, pid_t *ctid); */ |
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| 28 | |
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| 29 | .text |
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| 30 | ENTRY(__clone) |
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| 31 | /* sanity check arguments. */ |
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| 32 | tst r4, r4 |
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| 33 | bt/s 0f |
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| 34 | tst r5, r5 |
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| 35 | bf 1f |
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| 36 | 0: |
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| 37 | bra .Lsyscall_error |
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| 38 | mov #-EINVAL,r0 |
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| 39 | 1: |
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| 40 | /* insert the args onto the new stack */ |
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| 41 | mov.l r7, @-r5 |
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| 42 | /* save the function pointer as the 0th element */ |
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| 43 | mov.l r4, @-r5 |
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| 44 | |
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| 45 | /* do the system call */ |
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| 46 | mov r6, r4 |
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| 47 | mov.l @r15, r6 |
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| 48 | mov.l @(8,r15), r7 |
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| 49 | mov.l @(4,r15), r0 |
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| 50 | mov #+SYS_ify(clone), r3 |
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| 51 | trapa #0x15 |
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| 52 | mov r0, r1 |
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| 53 | mov #-12, r2 |
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| 54 | shad r2, r1 |
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| 55 | not r1, r1 // r1=0 means r0 = -1 to -4095 |
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| 56 | tst r1, r1 // i.e. error in linux |
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| 57 | bf .Lclone_end |
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| 58 | .Lsyscall_error: |
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| 59 | SYSCALL_ERROR_HANDLER |
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| 60 | .Lclone_end: |
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| 61 | tst r0, r0 |
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| 62 | bt 2f |
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| 63 | .Lpseudo_end: |
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| 64 | rts |
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| 65 | nop |
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| 66 | 2: |
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| 67 | /* terminate the stack frame */ |
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| 68 | mov #0, r14 |
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| 69 | |
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| 70 | /* thread starts */ |
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| 71 | mov.l @r15, r1 |
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| 72 | jsr @r1 |
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| 73 | mov.l @(4,r15), r4 |
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| 74 | |
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| 75 | /* we are done, passing the return value through r0 */ |
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| 76 | mov r0, r4 |
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| 77 | mov #+SYS_ify(exit), r3 |
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| 78 | trapa #0x15 |
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| 79 | .align 2 |
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| 80 | .LG: |
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| 81 | .long _GLOBAL_OFFSET_TABLE_ |
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| 82 | .L3: |
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| 83 | .long PLTJMP(C_SYMBOL_NAME(_exit)) |
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| 84 | PSEUDO_END (__clone) |
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| 85 | |
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| 86 | libc_hidden_def (__clone) |
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| 87 | weak_alias (__clone, clone) |
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| 88 | |
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