| 1 | /* Wrapper around clone system call. C-SKY ABIV2 version. |
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| 2 | Copyright (C) 2018-2024 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 | #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 *ptid, struct user_desc *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 | cmpnei a0, 0 /* No NULL function pointers. */ |
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| 33 | bf __error_arg |
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| 34 | cmpnei a1, 0 /* No NULL stack pointers. */ |
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| 35 | bf __error_arg |
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| 36 | |
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| 37 | subi a1, 8 |
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| 38 | stw a0, (a1, 0) /* Insert the function into the new stack. */ |
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| 39 | stw a3, (a1, 4) /* Insert the args into the new stack. */ |
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| 40 | |
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| 41 | mov t1, r7 /* Save r7. */ |
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| 42 | mov t2, r4 /* Save r4. */ |
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| 43 | |
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| 44 | /* The syscall expects the args to be in different slots. */ |
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| 45 | mov a0, a2 |
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| 46 | ldw a2, (sp, 0) |
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| 47 | ldw a3, (sp, 8) |
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| 48 | ldw r4, (sp, 4) |
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| 49 | lrw r7, __NR_clone |
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| 50 | trap 0 |
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| 51 | |
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| 52 | mov r7, t1 /* Restore r7. */ |
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| 53 | mov r4, t2 /* Restore r4. */ |
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| 54 | btsti a0, 31 /* Check if return is less than zero. */ |
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| 55 | bt __do_syscall_error |
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| 56 | cmpnei a0, 0 |
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| 57 | bf __thread_start |
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| 58 | rts |
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| 59 | |
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| 60 | __error_arg: |
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| 61 | lrw a0, -EINVAL |
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| 62 | |
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| 63 | __do_syscall_error: |
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| 64 | #ifdef __PIC__ |
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| 65 | subi sp, 8 |
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| 66 | stw gb, (sp, 0) |
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| 67 | stw r15, (sp, 4) |
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| 68 | grs gb, .Lgetpc |
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| 69 | .Lgetpc: |
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| 70 | lrw t0, .Lgetpc@GOTPC |
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| 71 | addu gb, gb, t0 |
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| 72 | lrw t0, __syscall_error@PLT |
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| 73 | ldr.w t0, (gb, t0 << 0) |
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| 74 | jsr t0 |
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| 75 | ldw gb, (sp, 0) |
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| 76 | ldw r15, (sp, 4) |
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| 77 | addi sp, 8 |
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| 78 | #else |
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| 79 | jmpi __syscall_error |
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| 80 | #endif /* __PIC__ */ |
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| 81 | rts |
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| 82 | PSEUDO_END (__clone) |
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| 83 | |
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| 84 | ENTRY (__thread_start) |
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| 85 | .cfi_label .Ldummy |
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| 86 | cfi_undefined (lr) |
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| 87 | ldw a0, (sp, 4) /* Restore args from new sp. */ |
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| 88 | ldw a1, (sp, 0) /* Restore function from new sp. */ |
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| 89 | addi sp, 8 |
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| 90 | jsr a1 |
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| 91 | |
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| 92 | /* exit */ |
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| 93 | lrw r7, __NR_exit |
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| 94 | trap 0 |
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| 95 | END (__thread_start) |
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| 96 | |
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| 97 | libc_hidden_def (__clone) |
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| 98 | weak_alias (__clone, clone) |
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| 99 | |
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