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
140
141
|
/*
* linux/kernel/futex_compat.c
*
* Futex compatibililty routines.
*
* Copyright 2006, Red Hat, Inc., Ingo Molnar
*/
#include <linux/linkage.h>
#include <linux/compat.h>
#include <linux/futex.h>
#include <asm/uaccess.h>
/*
* Walk curr->robust_list (very carefully, it's a userspace list!)
* and mark any locks found there dead, and notify any waiters.
*
* We silently return on any sign of list-walking problem.
*/
void compat_exit_robust_list(struct task_struct *curr)
{
struct compat_robust_list_head __user *head = curr->compat_robust_list;
struct robust_list __user *entry, *pending;
compat_uptr_t uentry, upending;
unsigned int limit = ROBUST_LIST_LIMIT;
compat_long_t futex_offset;
/*
* Fetch the list head (which was registered earlier, via
* sys_set_robust_list()):
*/
if (get_user(uentry, &head->list.next))
return;
entry = compat_ptr(uentry);
/*
* Fetch the relative futex offset:
*/
if (get_user(futex_offset, &head->futex_offset))
return;
/*
* Fetch any possibly pending lock-add first, and handle it
* if it exists:
*/
if (get_user(upending, &head->list_op_pending))
return;
pending = compat_ptr(upending);
if (upending)
handle_futex_death((void *)pending + futex_offset, curr);
while (compat_ptr(uentry) != &head->list) {
/*
* A pending lock might already be on the list, so
* dont process it twice:
*/
if (entry != pending)
if (handle_futex_death((void *)entry + futex_offset,
curr))
return;
/*
* Fetch the next entry in the list:
*/
if (get_user(uentry, (compat_uptr_t *)&entry->next))
return;
entry = compat_ptr(uentry);
/*
* Avoid excessively long or circular lists:
*/
if (!--limit)
break;
cond_resched();
}
}
asmlinkage long
compat_sys_set_robust_list(struct compat_robust_list_head __user *head,
compat_size_t len)
{
if (unlikely(len != sizeof(*head)))
return -EINVAL;
current->compat_robust_list = head;
return 0;
}
asmlinkage long
compat_sys_get_robust_list(int pid, compat_uptr_t *head_ptr,
compat_size_t __user *len_ptr)
{
struct compat_robust_list_head *head;
unsigned long ret;
if (!pid)
head = current->compat_robust_list;
else {
struct task_struct *p;
ret = -ESRCH;
read_lock(&tasklist_lock);
p = find_task_by_pid(pid);
if (!p)
goto err_unlock;
ret = -EPERM;
if ((current->euid != p->euid) && (current->euid != p->uid) &&
!capable(CAP_SYS_PTRACE))
goto err_unlock;
head = p->compat_robust_list;
read_unlock(&tasklist_lock);
}
if (put_user(sizeof(*head), len_ptr))
return -EFAULT;
return put_user(ptr_to_compat(head), head_ptr);
err_unlock:
read_unlock(&tasklist_lock);
return ret;
}
asmlinkage long compat_sys_futex(u32 __user *uaddr, int op, u32 val,
struct compat_timespec __user *utime, u32 __user *uaddr2,
u32 val3)
{
struct timespec t;
unsigned long timeout = MAX_SCHEDULE_TIMEOUT;
int val2 = 0;
if ((op == FUTEX_WAIT) && utime) {
if (get_compat_timespec(&t, utime))
return -EFAULT;
timeout = timespec_to_jiffies(&t) + 1;
}
if (op >= FUTEX_REQUEUE)
val2 = (int) (unsigned long) utime;
return do_futex(uaddr, op, val, timeout, uaddr2, val2, val3);
}
|
