| 1 | /* Wrapper around clone system call. 64 bit S/390 version. |
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| 2 | Copyright (C) 2001-2024 Free Software Foundation, Inc. |
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| 3 | This file is part of the GNU C Library. |
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| 4 | |
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| 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 |
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| 7 | License as published by the Free Software Foundation; either |
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| 8 | version 2.1 of the License, or (at your option) any later version. |
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| 9 | |
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| 10 | The GNU C Library is distributed in the hope that it will be useful, |
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| 11 | but WITHOUT ANY WARRANTY; without even the implied warranty of |
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| 12 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU |
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| 13 | Lesser General Public License for more details. |
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| 14 | |
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| 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 |
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| 17 | <https://www.gnu.org/licenses/>. */ |
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| 18 | |
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| 19 | /* clone is even more special than fork as it mucks with stacks |
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| 20 | and invokes a function in the right context after its all over. */ |
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| 21 | |
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| 22 | #include <sysdep.h> |
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| 23 | #include <tls.h> |
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| 24 | #define _ERRNO_H 1 |
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| 25 | #include <bits/errno.h> |
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| 26 | |
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| 27 | /* int __clone(int (*fn)(void *arg), void *child_stack, int flags, void *arg, |
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| 28 | pid_t *parent_tid, void *tls, pid_t *child_tid); */ |
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| 29 | /* sys_clone (void *child_stack, unsigned long flags, |
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| 30 | pid_t *parent_tid, pid_t *child_tid, void *tls); */ |
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| 31 | |
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| 32 | .text |
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| 33 | ENTRY(__clone) |
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| 34 | stmg %r6,%r7,48(%r15) /* Save registers. */ |
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| 35 | cfi_offset (%r7,-104) |
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| 36 | cfi_offset (%r6,-112) |
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| 37 | ltgr %r7,%r2 /* check fn and move to %r7 */ |
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| 38 | jz error /* no NULL function pointers */ |
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| 39 | lghi %r0,-16 /* Align the child_stack to a ... */ |
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| 40 | ngr %r3,%r0 /* double word boundary and ... */ |
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| 41 | jz error /* avoid NULL stack pointers. */ |
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| 42 | lgr %r0,%r5 /* move *arg out of the way */ |
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| 43 | lgr %r2,%r3 /* move child_stack to %r2 */ |
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| 44 | lgr %r3,%r4 /* move flags to %r3 */ |
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| 45 | lgr %r4,%r6 /* move parent_tid to %r4 */ |
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| 46 | lg %r5,168(%r15) /* load child_tid from stack */ |
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| 47 | lg %r6,160(%r15) /* load tls from stack */ |
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| 48 | lghi %r1,SYS_ify (clone) |
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| 49 | svc 0 |
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| 50 | ltgr %r2,%r2 /* check return code */ |
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| 51 | jz thread_start |
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| 52 | lmg %r6,%r7,48(%r15) /* Restore registers. */ |
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| 53 | jgm SYSCALL_ERROR_LABEL |
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| 54 | br %r14 |
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| 55 | error: |
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| 56 | lghi %r2,-EINVAL |
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| 57 | lmg %r6,%r7,48(%r15) /* Restore registers. */ |
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| 58 | jg SYSCALL_ERROR_LABEL |
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| 59 | PSEUDO_END (__clone) |
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| 60 | |
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| 61 | thread_start: |
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| 62 | cfi_startproc |
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| 63 | /* Mark r14 as undefined in order to stop unwinding here! */ |
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| 64 | cfi_undefined (r14) |
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| 65 | /* fn is in gpr 7, arg in gpr 0 */ |
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| 66 | lgr %r2,%r0 /* set first parameter to void *arg */ |
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| 67 | aghi %r15,-160 /* make room on the stack for the save area */ |
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| 68 | xc 0(8,%r15),0(%r15) |
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| 69 | basr %r14,%r7 /* jump to fn */ |
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| 70 | DO_CALL (exit, 1) |
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| 71 | cfi_endproc |
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| 72 | |
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| 73 | libc_hidden_def (__clone) |
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| 74 | weak_alias (__clone, clone) |
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| 75 | |
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