about summary refs log tree commit diff
path: root/sysdeps/unix/sysv/linux/mips/clone3.S
blob: 1d16bfcef6e03a1330577c551aed15972afa8a56 (plain) (blame)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
/* The clone3 syscall wrapper.  Linux/mips version.
   Copyright (C) 2023 Free Software Foundation, Inc.

   This file is part of the GNU C Library.

   The GNU C Library is free software; you can redistribute it and/or
   modify it under the terms of the GNU Lesser General Public
   License as published by the Free Software Foundation; either
   version 2.1 of the License, or (at your option) any later version.

   The GNU C Library is distributed in the hope that it will be useful,
   but WITHOUT ANY WARRANTY; without even the implied warranty of
   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
   Lesser General Public License for more details.

   You should have received a copy of the GNU Lesser General Public
   License along with the GNU C Library; if not, see
   <https://www.gnu.org/licenses/>.  */

#include <sys/asm.h>
#include <sysdep.h>
#define _ERRNO_H        1
#include <bits/errno.h>

/* The userland implementation is:
   int clone3 (struct clone_args *cl_args, size_t size,
               int (*func)(void *arg), void *arg);

   the kernel entry is:
   int clone3 (struct clone_args *cl_args, size_t size);

   The parameters are passed in registers from userland:
   a0/$4: cl_args
   a1/$5: size
   a2/$6: func
   a3/$7: arg  */

	.text
	.set		nomips16
#if _MIPS_SIM == _ABIO32
# define EXTRA_LOCALS 1
#else
# define EXTRA_LOCALS 0
#endif
#define FRAMESZ ((NARGSAVE*SZREG)+ALSZ)&ALMASK
GPOFF= FRAMESZ-(1*SZREG)
NESTED(__clone3, SZREG, sp)
#ifdef __PIC__
	SETUP_GP
#endif
#if FRAMESZ
	PTR_SUBU sp, FRAMESZ
	cfi_adjust_cfa_offset (FRAMESZ)
#endif
	SETUP_GP64_STACK (GPOFF, __clone3)
#ifdef __PIC__
	SAVE_GP (GPOFF)
#endif
#ifdef PROF
	.set	noat
	move	$1,ra
	jal	_mcount
	.set	at
#endif

	/* Sanity check args.  */
	li	v0, EINVAL
	beqz	a0, L(error)	/* No NULL cl_args pointer.  */
	beqz	a2, L(error)	/* No NULL function pointer.  */

	move	$8, a3		/* a3 is set to 0/1 for syscall success/error
				   while a4/$8 is returned unmodified.  */

	/* Do the system call, the kernel expects:
	   v0: system call number
	   a0: cl_args
	   a1: size  */
	li		v0, __NR_clone3
	cfi_endproc
	syscall

	bnez		a3, L(error)
	beqz		v0, L(thread_start_clone3)

	/* Successful return from the parent */
	cfi_startproc
#if FRAMESZ
	cfi_adjust_cfa_offset (FRAMESZ)
#endif
	SETUP_GP64_STACK_CFI (GPOFF)
	cfi_remember_state
	RESTORE_GP64_STACK
#if FRAMESZ
	PTR_ADDU	sp, FRAMESZ
	cfi_adjust_cfa_offset (-FRAMESZ)
#endif
	ret

L(error):
	cfi_restore_state
#ifdef __PIC__
	PTR_LA		t9, __syscall_error
	RESTORE_GP64_STACK
	PTR_ADDU	sp, FRAMESZ
	cfi_adjust_cfa_offset (-FRAMESZ)
	jr		t9
#else
	RESTORE_GP64_STACK
	PTR_ADDU	sp, FRAMESZ
	cfi_adjust_cfa_offset (-FRAMESZ)
	j		__syscall_error
#endif
END (__clone3)

/* Load up the arguments to the function.  Put this block of code in
   its own function so that we can terminate the stack trace with our
   debug info.  */

ENTRY(__thread_start_clone3)
L(thread_start_clone3):
	cfi_undefined ($31)
	/* cp is already loaded.  */
	SAVE_GP (GPOFF)
	/* The stackframe has been created on entry of clone3.  */

	/* Restore the arg for user's function.  */
	move		t9, a2		/* Function pointer.  */
	move		a0, $8		/* Argument pointer.  */

	/* Call the user's function.  */
	jal		t9

	move		a0, v0
	li		v0, __NR_exit
	syscall
END(__thread_start_clone3)

libc_hidden_def (__clone3)
weak_alias (__clone3, clone3)