1// SPDX-License-Identifier: GPL-2.0
2
3/*
4 * This file handles the architecture independent parts of process handling..
5 */
6
7#include <linux/compat.h>
8#include <linux/errno.h>
9#include <linux/kernel.h>
10#include <linux/ptrace.h>
11#include <linux/sched.h>
12#include <linux/sched/task.h>
13#include <linux/sched/task_stack.h>
14#include <linux/signal.h>
15
16#include "kernel.h"
17
18asmlinkage long sparc_fork(struct pt_regs *regs)
19{
20 unsigned long orig_i1 = regs->u_regs[UREG_I1];
21 long ret;
22 struct kernel_clone_args args = {
23 .exit_signal = SIGCHLD,
24 /* Reuse the parent's stack for the child. */
25 .stack = regs->u_regs[UREG_FP],
26 };
27
28 ret = kernel_clone(kargs: &args);
29
30 /* If we get an error and potentially restart the system
31 * call, we're screwed because copy_thread() clobbered
32 * the parent's %o1. So detect that case and restore it
33 * here.
34 */
35 if ((unsigned long)ret >= -ERESTART_RESTARTBLOCK)
36 regs->u_regs[UREG_I1] = orig_i1;
37
38 return ret;
39}
40
41asmlinkage long sparc_vfork(struct pt_regs *regs)
42{
43 unsigned long orig_i1 = regs->u_regs[UREG_I1];
44 long ret;
45
46 struct kernel_clone_args args = {
47 .flags = CLONE_VFORK | CLONE_VM,
48 .exit_signal = SIGCHLD,
49 /* Reuse the parent's stack for the child. */
50 .stack = regs->u_regs[UREG_FP],
51 };
52
53 ret = kernel_clone(kargs: &args);
54
55 /* If we get an error and potentially restart the system
56 * call, we're screwed because copy_thread() clobbered
57 * the parent's %o1. So detect that case and restore it
58 * here.
59 */
60 if ((unsigned long)ret >= -ERESTART_RESTARTBLOCK)
61 regs->u_regs[UREG_I1] = orig_i1;
62
63 return ret;
64}
65
66asmlinkage long sparc_clone(struct pt_regs *regs)
67{
68 unsigned long orig_i1 = regs->u_regs[UREG_I1];
69 unsigned int flags = lower_32_bits(regs->u_regs[UREG_I0]);
70 long ret;
71
72 struct kernel_clone_args args = {
73 .flags = (flags & ~CSIGNAL),
74 .exit_signal = (flags & CSIGNAL),
75 .tls = regs->u_regs[UREG_I3],
76 };
77
78#ifdef CONFIG_COMPAT
79 if (test_thread_flag(TIF_32BIT)) {
80 args.pidfd = compat_ptr(regs->u_regs[UREG_I2]);
81 args.child_tid = compat_ptr(regs->u_regs[UREG_I4]);
82 args.parent_tid = compat_ptr(regs->u_regs[UREG_I2]);
83 } else
84#endif
85 {
86 args.pidfd = (int __user *)regs->u_regs[UREG_I2];
87 args.child_tid = (int __user *)regs->u_regs[UREG_I4];
88 args.parent_tid = (int __user *)regs->u_regs[UREG_I2];
89 }
90
91 /* Did userspace give setup a separate stack for the child or are we
92 * reusing the parent's?
93 */
94 if (regs->u_regs[UREG_I1])
95 args.stack = regs->u_regs[UREG_I1];
96 else
97 args.stack = regs->u_regs[UREG_FP];
98
99 ret = kernel_clone(kargs: &args);
100
101 /* If we get an error and potentially restart the system
102 * call, we're screwed because copy_thread() clobbered
103 * the parent's %o1. So detect that case and restore it
104 * here.
105 */
106 if ((unsigned long)ret >= -ERESTART_RESTARTBLOCK)
107 regs->u_regs[UREG_I1] = orig_i1;
108
109 return ret;
110}
111

source code of linux/arch/sparc/kernel/process.c