| 1 | /* Copyright (C) 2000-2024 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 | /* 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 | #include <tls.h> |
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| 23 | #define _ERRNO_H 1 |
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| 24 | #include <bits/errno.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 *parent_tid, void *tls, pid_t *child_tid); */ |
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| 28 | /* sys_clone (void *child_stack, unsigned long flags, |
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| 29 | pid_t *parent_tid, pid_t *child_tid, void *tls); */ |
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| 30 | |
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| 31 | .text |
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| 32 | ENTRY(__clone) |
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| 33 | stm %r6,%r7,24(%r15) /* Save registers. */ |
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| 34 | cfi_offset (%r7, -68) |
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| 35 | cfi_offset (%r6, -72) |
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| 36 | ltr %r7,%r2 /* check fn and move to %r7 */ |
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| 37 | jz error /* no NULL function pointers */ |
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| 38 | lhi %r0,-8 /* Align the child_stack to a ... */ |
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| 39 | nr %r3,%r0 /* double word boundary and ... */ |
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| 40 | jz error /* avoid NULL stack pointers. */ |
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| 41 | lr %r0,%r5 /* move *arg out of the way */ |
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| 42 | lr %r2,%r3 /* move child_stack to %r2 */ |
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| 43 | lr %r3,%r4 /* move flags to %r3 */ |
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| 44 | lr %r4,%r6 /* move parent_tid to %r4 */ |
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| 45 | l %r5,100(%r15) /* load child_tid from stack */ |
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| 46 | l %r6,96(%r15) /* load tls from stack */ |
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| 47 | lhi %r1,SYS_ify(clone) |
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| 48 | svc 0 |
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| 49 | ltr %r2,%r2 /* check return code */ |
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| 50 | jz thread_start |
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| 51 | lm %r6,%r7,24(%r15) /* Load registers. */ |
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| 52 | jm SYSCALL_ERROR_LABEL |
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| 53 | br %r14 |
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| 54 | error: |
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| 55 | lhi %r2,-EINVAL |
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| 56 | lm %r6,%r7,24(%r15) /* Load registers. */ |
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| 57 | j SYSCALL_ERROR_LABEL |
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| 58 | PSEUDO_END (__clone) |
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| 59 | |
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| 60 | thread_start: |
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| 61 | cfi_startproc |
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| 62 | /* Mark r14 as undefined in order to stop unwinding here! */ |
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| 63 | cfi_undefined (r14) |
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| 64 | /* fn is in gpr 7, arg in gpr 0 */ |
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| 65 | lr %r2,%r0 /* set first parameter to void *arg */ |
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| 66 | ahi %r15,-96 /* make room on the stack for the save area */ |
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| 67 | xc 0(4,%r15),0(%r15) |
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| 68 | basr %r14,%r7 /* jump to fn */ |
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| 69 | DO_CALL (exit, 1) |
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| 70 | cfi_endproc |
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| 71 | |
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| 72 | libc_hidden_def (__clone) |
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| 73 | weak_alias (__clone, clone) |
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| 74 | |
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