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
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
|
/*
* linux/kernel/signal.c
*
* Copyright (C) 1991, 1992 Linus Torvalds
*/
#include <linux/sched.h>
#include <linux/kernel.h>
#include <linux/signal.h>
#include <linux/errno.h>
#include <linux/wait.h>
#include <linux/ptrace.h>
#include <linux/unistd.h>
#include <linux/mm.h>
#include <asm/uaccess.h>
#define _S(nr) (1<<((nr)-1))
#define _BLOCKABLE (~(_S(SIGKILL) | _S(SIGSTOP)))
#if !defined(__alpha__) && !defined(__mips__)
/*
* This call isn't used by all ports, in particular, the Alpha
* uses osf_sigprocmask instead. Maybe it should be moved into
* arch-dependent dir?
*/
asmlinkage int sys_sigprocmask(int how, sigset_t *set, sigset_t *oset)
{
sigset_t new_set, old_set = current->blocked;
int error;
if (set) {
error = get_user(new_set, set);
if (error)
return error;
new_set &= _BLOCKABLE;
switch (how) {
case SIG_BLOCK:
current->blocked |= new_set;
break;
case SIG_UNBLOCK:
current->blocked &= ~new_set;
break;
case SIG_SETMASK:
current->blocked = new_set;
break;
default:
return -EINVAL;
}
}
if (oset) {
error = put_user(old_set, oset);
if (error)
return error;
}
return 0;
}
#endif
#ifndef __alpha__
/*
* For backwards compatibility? Functionality superseded by sigprocmask.
*/
asmlinkage int sys_sgetmask(void)
{
return current->blocked;
}
asmlinkage int sys_ssetmask(int newmask)
{
int old=current->blocked;
current->blocked = newmask & _BLOCKABLE;
return old;
}
#endif
asmlinkage int sys_sigpending(sigset_t *set)
{
return put_user(current->blocked & current->signal,
/* Hack */(unsigned long *)set);
}
/*
* POSIX 3.3.1.3:
* "Setting a signal action to SIG_IGN for a signal that is pending
* shall cause the pending signal to be discarded, whether or not
* it is blocked."
*
* "Setting a signal action to SIG_DFL for a signal that is pending
* and whose default action is to ignore the signal (for example,
* SIGCHLD), shall cause the pending signal to be discarded, whether
* or not it is blocked"
*
* Note the silly behaviour of SIGCHLD: SIG_IGN means that the signal
* isn't actually ignored, but does automatic child reaping, while
* SIG_DFL is explicitly said by POSIX to force the signal to be ignored..
*/
static inline void check_pending(int signum)
{
struct sigaction *p;
p = signum - 1 + current->sig->action;
if (p->sa_handler == SIG_IGN) {
k_sigdelset(¤t->signal, signum);
return;
}
if (p->sa_handler == SIG_DFL) {
if (signum != SIGCONT && signum != SIGCHLD && signum != SIGWINCH)
return;
k_sigdelset(¤t->signal, signum);
return;
}
}
#if !defined(__alpha__) && !defined(__mips__)
/*
* For backwards compatibility? Functionality superseded by sigaction.
*/
asmlinkage unsigned long sys_signal(int signum, __sighandler_t handler)
{
int err;
struct sigaction tmp;
/*
* HACK: We still cannot handle signals > 32 due to the limited
* size of ksigset_t (which will go away).
*/
if (signum > 32)
return -EINVAL;
if (signum<1 || signum>_NSIG)
return -EINVAL;
if (signum==SIGKILL || signum==SIGSTOP)
return -EINVAL;
if (handler != SIG_DFL && handler != SIG_IGN) {
err = verify_area(VERIFY_READ, handler, 1);
if (err)
return err;
}
memset(&tmp, 0, sizeof(tmp));
tmp.sa_handler = handler;
tmp.sa_flags = SA_ONESHOT | SA_NOMASK;
handler = current->sig->action[signum-1].sa_handler;
current->sig->action[signum-1] = tmp;
check_pending(signum);
return (unsigned long) handler;
}
#endif /* !defined(__alpha__) && !defined(__mips__) */
asmlinkage int sys_sigaction(int signum, const struct sigaction * action,
struct sigaction * oldaction)
{
struct sigaction new_sa, *p;
/*
* HACK: We still cannot handle signals > 32 due to the limited
* size of ksigset_t (which will go away).
*/
if (signum > 32)
return -EINVAL;
if (signum<1 || signum>_NSIG)
return -EINVAL;
p = signum - 1 + current->sig->action;
if (action) {
int err = verify_area(VERIFY_READ, action, sizeof(*action));
if (err)
return err;
if (signum==SIGKILL || signum==SIGSTOP)
return -EINVAL;
if (copy_from_user(&new_sa, action, sizeof(struct sigaction)))
return -EFAULT;
if (new_sa.sa_handler != SIG_DFL && new_sa.sa_handler != SIG_IGN) {
err = verify_area(VERIFY_READ, new_sa.sa_handler, 1);
if (err)
return err;
}
}
if (oldaction) {
if (copy_to_user(oldaction, p, sizeof(struct sigaction)))
return -EFAULT;
}
if (action) {
*p = new_sa;
check_pending(signum);
}
return 0;
}
|
