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
|
/*
* Copyright 2003 PathScale, Inc.
*
* Licensed under the GPL
*/
#include "linux/linkage.h"
#include "linux/slab.h"
#include "linux/shm.h"
#include "linux/utsname.h"
#include "linux/personality.h"
#include "asm/uaccess.h"
#define __FRAME_OFFSETS
#include "asm/ptrace.h"
#include "asm/unistd.h"
#include "asm/prctl.h" /* XXX This should get the constants from libc */
#include "kern.h"
#include "os.h"
asmlinkage long sys_uname64(struct new_utsname __user * name)
{
int err;
down_read(&uts_sem);
err = copy_to_user(name, utsname(), sizeof (*name));
up_read(&uts_sem);
if (personality(current->personality) == PER_LINUX32)
err |= copy_to_user(&name->machine, "i686", 5);
return err ? -EFAULT : 0;
}
long arch_prctl(struct task_struct *task, int code, unsigned long __user *addr)
{
unsigned long *ptr = addr, tmp;
long ret;
int pid = task->mm->context.skas.id.u.pid;
/*
* With ARCH_SET_FS (and ARCH_SET_GS is treated similarly to
* be safe), we need to call arch_prctl on the host because
* setting %fs may result in something else happening (like a
* GDT or thread.fs being set instead). So, we let the host
* fiddle the registers and thread struct and restore the
* registers afterwards.
*
* So, the saved registers are stored to the process (this
* needed because a stub may have been the last thing to run),
* arch_prctl is run on the host, then the registers are read
* back.
*/
switch(code){
case ARCH_SET_FS:
case ARCH_SET_GS:
restore_registers(pid, ¤t->thread.regs.regs);
break;
case ARCH_GET_FS:
case ARCH_GET_GS:
/*
* With these two, we read to a local pointer and
* put_user it to the userspace pointer that we were
* given. If addr isn't valid (because it hasn't been
* faulted in or is just bogus), we want put_user to
* fault it in (or return -EFAULT) instead of having
* the host return -EFAULT.
*/
ptr = &tmp;
}
ret = os_arch_prctl(pid, code, ptr);
if(ret)
return ret;
switch(code){
case ARCH_SET_FS:
current->thread.arch.fs = (unsigned long) ptr;
save_registers(pid, ¤t->thread.regs.regs);
break;
case ARCH_SET_GS:
save_registers(pid, ¤t->thread.regs.regs);
break;
case ARCH_GET_FS:
ret = put_user(tmp, addr);
break;
case ARCH_GET_GS:
ret = put_user(tmp, addr);
break;
}
return ret;
}
long sys_arch_prctl(int code, unsigned long addr)
{
return arch_prctl(current, code, (unsigned long __user *) addr);
}
long sys_clone(unsigned long clone_flags, unsigned long newsp,
void __user *parent_tid, void __user *child_tid)
{
long ret;
if (!newsp)
newsp = UPT_SP(¤t->thread.regs.regs);
current->thread.forking = 1;
ret = do_fork(clone_flags, newsp, ¤t->thread.regs, 0, parent_tid,
child_tid);
current->thread.forking = 0;
return ret;
}
void arch_switch_to(struct task_struct *from, struct task_struct *to)
{
if((to->thread.arch.fs == 0) || (to->mm == NULL))
return;
arch_prctl(to, ARCH_SET_FS, (void __user *) to->thread.arch.fs);
}
|
