1 /* Wrapper around clone system call. PowerPC64 version.
2 Copyright (C) 1997-2021 Free Software Foundation, Inc.
3 This file is part of the GNU C Library.
5 The GNU C Library is free software; you can redistribute it and/or
6 modify it under the terms of the GNU Lesser General Public
7 License as published by the Free Software Foundation; either
8 version 2.1 of the License, or (at your option) any later version.
10 The GNU C Library is distributed in the hope that it will be useful,
11 but WITHOUT ANY WARRANTY; without even the implied warranty of
12 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
13 Lesser General Public License for more details.
15 You should have received a copy of the GNU Lesser General Public
16 License along with the GNU C Library; if not, see
17 <https://www.gnu.org/licenses/>. */
21 #include <bits/errno.h>
23 /* This is the only really unusual system call in PPC linux, but not
24 because of any weirdness in the system call itself; because of
25 all the freaky stuff we have to do to make the call useful. */
27 /* int [r3] clone(int (*fn)(void *arg) [r3], void *child_stack [r4],
28 int flags [r5], void *arg [r6], void *parent_tid [r7],
29 void *tls [r8], void *child_tid [r9]); */
34 /* Check for child_stack == NULL || fn == NULL. */
37 cror cr0*4+eq,cr1*4+eq,cr0*4+eq
40 /* Save some regs in the "red zone". */
52 /* Set up stack frame for child. */
55 stdu r0,-FRAME_MIN_SIZE_PARM(r4)
57 /* Save fn, args, stack across syscall. */
58 mr r30,r3 /* Function in r30. */
59 mr r29,r5 /* Flags in r29. */
60 mr r31,r6 /* Argument in r31. */
62 /* 'flags' argument is first parameter to clone syscall.
63 Second is the stack pointer, already in r4. */
65 /* Move the parent_tid, child_tid and tls arguments. */
70 /* End FDE now, because in the child the unwind info will be
77 CHECK_SCV_SUPPORT r28 0f
78 /* This is equivalent to DO_CALL_SCV, but we cannot use the macro here
79 because it uses CFI directives and we just called cfi_endproc. */
81 std r9,FRAME_LR_SAVE(r1)
86 ld r9,FRAME_LR_SAVE(r1)
89 /* Check for child process. */
90 /* When using scv, error is indicated by negative r3. */
93 #endif /* USE_PPC_SCV */
96 /* Check for child process. */
97 /* With sc, error is indicated by cr0.SO. */
99 crandc cr1*4+eq,cr1*4+eq,cr0*4+so
101 bne- cr1,L(parent) /* The '-' is to minimise the race. */
103 std r2,FRAME_TOC_SAVE(r1)
104 /* Call procedure. */
105 PPC64_LOAD_FUNCPTR r30
108 ld r2,FRAME_TOC_SAVE(r1)
110 li r0,(SYS_ify(exit))
112 /* We won't ever get here but provide a nop so that the linker
113 will insert a toc adjusting stub if necessary. */
119 TAIL_CALL_SYSCALL_ERROR
122 /* Check if scv is available. */
125 /* Parent. Restore registers & return. */
147 1: TAIL_CALL_SYSCALL_ERROR
152 libc_hidden_def (__clone)
153 weak_alias (__clone, clone)