| 1 | /* Copyright (C) 1997-2024 Free Software Foundation, Inc. |
| 2 | This file is part of the GNU C Library. |
| 3 | |
| 4 | The GNU C Library is free software; you can redistribute it and/or |
| 5 | modify it under the terms of the GNU Lesser General Public |
| 6 | License as published by the Free Software Foundation; either |
| 7 | version 2.1 of the License, or (at your option) any later version. |
| 8 | |
| 9 | The GNU C Library is distributed in the hope that it will be useful, |
| 10 | but WITHOUT ANY WARRANTY; without even the implied warranty of |
| 11 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU |
| 12 | Lesser General Public License for more details. |
| 13 | |
| 14 | You should have received a copy of the GNU Lesser General Public |
| 15 | License along with the GNU C Library; if not, see |
| 16 | <https://www.gnu.org/licenses/>. */ |
| 17 | |
| 18 | /* clone() is even more special than fork() as it mucks with stacks |
| 19 | and invokes a function in the right context after its all over. */ |
| 20 | |
| 21 | #include <asm/errno.h> |
| 22 | #include <tcb-offsets.h> |
| 23 | #include <sysdep.h> |
| 24 | |
| 25 | /* int clone(int (*fn)(void *arg), void *child_stack, int flags, void *arg, |
| 26 | pid_t *ptid, void *tls, pid_t *ctid); */ |
| 27 | |
| 28 | .register %g2,#scratch |
| 29 | .register %g3,#scratch |
| 30 | |
| 31 | .text |
| 32 | |
| 33 | ENTRY (__clone) |
| 34 | save %sp, -192, %sp |
| 35 | cfi_def_cfa_register(%fp) |
| 36 | cfi_window_save |
| 37 | cfi_register(%o7, %i7) |
| 38 | |
| 39 | /* sanity check arguments */ |
| 40 | brz,pn %i0, 99f /* fn non-NULL? */ |
| 41 | mov %i0, %g2 |
| 42 | brz,pn %i1, 99f /* child_stack non-NULL? */ |
| 43 | mov %i2, %o0 /* clone flags */ |
| 44 | |
| 45 | /* The child_stack is the top of the stack, allocate one |
| 46 | whole stack frame from that as this is what the kernel |
| 47 | expects. Also, subtract STACK_BIAS. */ |
| 48 | sub %i1, 192 + 0x7ff, %o1 |
| 49 | mov %i3, %g3 |
| 50 | |
| 51 | mov %i4,%o2 /* PTID */ |
| 52 | mov %i5,%o3 /* TLS */ |
| 53 | ldx [%fp+0x7ff+176],%o4 /* CTID */ |
| 54 | |
| 55 | /* Do the system call */ |
| 56 | set __NR_clone, %g1 |
| 57 | ta 0x6d |
| 58 | bcs,pn %xcc, 98f |
| 59 | nop |
| 60 | brnz,pn %o1, __thread_start |
| 61 | nop |
| 62 | jmpl %i7 + 8, %g0 |
| 63 | restore %o0, %g0, %o0 |
| 64 | 99: mov EINVAL, %o0 |
| 65 | 98: call HIDDEN_JUMPTARGET(__errno_location) |
| 66 | mov %o0, %i0 |
| 67 | st %i0, [%o0] |
| 68 | jmpl %i7 + 8, %g0 |
| 69 | restore %g0,-1,%o0 |
| 70 | END(__clone) |
| 71 | |
| 72 | .type __thread_start,@function |
| 73 | __thread_start: |
| 74 | mov %g0, %fp /* terminate backtrace */ |
| 75 | call %g2 |
| 76 | mov %g3,%o0 |
| 77 | set __NR_exit, %g1 |
| 78 | ta 0x6d |
| 79 | nop |
| 80 | |
| 81 | .size __thread_start, .-__thread_start |
| 82 | |
| 83 | libc_hidden_def (__clone) |
| 84 | weak_alias (__clone, clone) |
| 85 | |