aboutsummaryrefslogtreecommitdiff
path: root/arch/arm/kernel/sys_arm.c
blob: 76cbb055dd05ee2e8620bc1a3f1dc322f1333aeb (plain)
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
/*
 *  linux/arch/arm/kernel/sys_arm.c
 *
 *  Copyright (C) People who wrote linux/arch/i386/kernel/sys_i386.c
 *  Copyright (C) 1995, 1996 Russell King.
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License version 2 as
 * published by the Free Software Foundation.
 *
 *  This file contains various random system calls that
 *  have a non-standard calling sequence on the Linux/arm
 *  platform.
 */
#include <linux/export.h>
#include <linux/errno.h>
#include <linux/sched.h>
#include <linux/mm.h>
#include <linux/sem.h>
#include <linux/msg.h>
#include <linux/shm.h>
#include <linux/stat.h>
#include <linux/syscalls.h>
#include <linux/mman.h>
#include <linux/fs.h>
#include <linux/file.h>
#include <linux/ipc.h>
#include <linux/uaccess.h>
#include <linux/slab.h>

/* Fork a new task - this creates a new program thread.
 * This is called indirectly via a small wrapper
 */
asmlinkage int sys_fork(struct pt_regs *regs)
{
#ifdef CONFIG_MMU
	return do_fork(SIGCHLD, regs->ARM_sp, regs, 0, NULL, NULL);
#else
	/* can not support in nommu mode */
	return(-EINVAL);
#endif
}

/* Clone a task - this clones the calling program thread.
 * This is called indirectly via a small wrapper
 */
asmlinkage int sys_clone(unsigned long clone_flags, unsigned long newsp,
			 int __user *parent_tidptr, int tls_val,
			 int __user *child_tidptr, struct pt_regs *regs)
{
	if (!newsp)
		newsp = regs->ARM_sp;

	return do_fork(clone_flags, newsp, regs, 0, parent_tidptr, child_tidptr);
}

asmlinkage int sys_vfork(struct pt_regs *regs)
{
	return do_fork(CLONE_VFORK | CLONE_VM | SIGCHLD, regs->ARM_sp, regs, 0, NULL, NULL);
}

/* sys_execve() executes a new program.
 * This is called indirectly via a small wrapper
 */
asmlinkage int sys_execve(const char __user *filenamei,
			  const char __user *const __user *argv,
			  const char __user *const __user *envp, struct pt_regs *regs)
{
	int error;
	char * filename;

	filename = getname(filenamei);
	error = PTR_ERR(filename);
	if (IS_ERR(filename))
		goto out;
	error = do_execve(filename, argv, envp, regs);
	putname(filename);
out:
	return error;
}

int kernel_execve(const char *filename,
		  const char *const argv[],
		  const char *const envp[])
{
	struct pt_regs regs;
	int ret;

	memset(&regs, 0, sizeof(struct pt_regs));
	ret = do_execve(filename,
			(const char __user *const __user *)argv,
			(const char __user *const __user *)envp, &regs);
	if (ret < 0)
		goto out;

	/*
	 * Save argc to the register structure for userspace.
	 */
	regs.ARM_r0 = ret;

	/*
	 * We were successful.  We won't be returning to our caller, but
	 * instead to user space by manipulating the kernel stack.
	 */
	asm(	"add	r0, %0, %1\n\t"
		"mov	r1, %2\n\t"
		"mov	r2, %3\n\t"
		"bl	memmove\n\t"	/* copy regs to top of stack */
		"mov	r8, #0\n\t"	/* not a syscall */
		"mov	r9, %0\n\t"	/* thread structure */
		"mov	sp, r0\n\t"	/* reposition stack pointer */
		"b	ret_to_user"
		:
		: "r" (current_thread_info()),
		  "Ir" (THREAD_START_SP - sizeof(regs)),
		  "r" (&regs),
		  "Ir" (sizeof(regs))
		: "r0", "r1", "r2", "r3", "r8", "r9", "ip", "lr", "memory");

 out:
	return ret;
}
EXPORT_SYMBOL(kernel_execve);

/*
 * Since loff_t is a 64 bit type we avoid a lot of ABI hassle
 * with a different argument ordering.
 */
asmlinkage long sys_arm_fadvise64_64(int fd, int advice,
				     loff_t offset, loff_t len)
{
	return sys_fadvise64_64(fd, offset, len, advice);
}