process.c

  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;
 21	long ret;
 22	struct kernel_clone_args args = {
 23		.exit_signal	= SIGCHLD,
 24	};
 25
 26	synchronize_user_stack();
 27
 28	orig_i1 = regs->u_regs[UREG_I1];
 29	/* Reuse the parent's stack for the child. */
 30	args.stack = regs->u_regs[UREG_FP];
 31
 32	ret = kernel_clone(&args);
 33
 34	/* If we get an error and potentially restart the system
 35	 * call, we're screwed because copy_thread() clobbered
 36	 * the parent's %o1.  So detect that case and restore it
 37	 * here.
 38	 */
 39	if ((unsigned long)ret >= -ERESTART_RESTARTBLOCK)
 40		regs->u_regs[UREG_I1] = orig_i1;
 41
 42	return ret;
 43}
 44
 45asmlinkage long sparc_vfork(struct pt_regs *regs)
 46{
 47	unsigned long orig_i1;
 48	long ret;
 49	struct kernel_clone_args args = {
 50		.flags		= CLONE_VFORK | CLONE_VM,
 51		.exit_signal	= SIGCHLD,
 52	};
 53
 54	synchronize_user_stack();
 55
 56	orig_i1 = regs->u_regs[UREG_I1];
 57	/* Reuse the parent's stack for the child. */
 58	args.stack = regs->u_regs[UREG_FP];
 59
 60	ret = kernel_clone(&args);
 61
 62	/* If we get an error and potentially restart the system
 63	 * call, we're screwed because copy_thread() clobbered
 64	 * the parent's %o1.  So detect that case and restore it
 65	 * here.
 66	 */
 67	if ((unsigned long)ret >= -ERESTART_RESTARTBLOCK)
 68		regs->u_regs[UREG_I1] = orig_i1;
 69
 70	return ret;
 71}
 72
 73asmlinkage long sparc_clone(struct pt_regs *regs)
 74{
 75	unsigned long orig_i1;
 76	unsigned int flags;
 77	long ret;
 78	struct kernel_clone_args args = {0};
 79
 80	synchronize_user_stack();
 81
 82	orig_i1 = regs->u_regs[UREG_I1];
 83	flags = lower_32_bits(regs->u_regs[UREG_I0]);
 84	args.flags		= (flags & ~CSIGNAL);
 85	args.exit_signal	= (flags & CSIGNAL);
 86	args.tls		= regs->u_regs[UREG_I3];
 87
 88#ifdef CONFIG_COMPAT
 89	if (test_thread_flag(TIF_32BIT)) {
 90		args.pidfd	= compat_ptr(regs->u_regs[UREG_I2]);
 91		args.child_tid	= compat_ptr(regs->u_regs[UREG_I4]);
 92		args.parent_tid	= compat_ptr(regs->u_regs[UREG_I2]);
 93	} else
 94#endif
 95	{
 96		args.pidfd	= (int __user *)regs->u_regs[UREG_I2];
 97		args.child_tid	= (int __user *)regs->u_regs[UREG_I4];
 98		args.parent_tid	= (int __user *)regs->u_regs[UREG_I2];
 99	}
100
101	/* Did userspace give setup a separate stack for the child or are we
102	 * reusing the parent's?
103	 */
104	if (regs->u_regs[UREG_I1])
105		args.stack = regs->u_regs[UREG_I1];
106	else
107		args.stack = regs->u_regs[UREG_FP];
108
109	ret = kernel_clone(&args);
110
111	/* If we get an error and potentially restart the system
112	 * call, we're screwed because copy_thread() clobbered
113	 * the parent's %o1.  So detect that case and restore it
114	 * here.
115	 */
116	if ((unsigned long)ret >= -ERESTART_RESTARTBLOCK)
117		regs->u_regs[UREG_I1] = orig_i1;
118
119	return ret;
120}