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
|
/*
* Copyright (C) 2000 Jeff Dike (jdike@karaya.com)
* Licensed under the GPL
*/
#include <stdio.h>
#include <unistd.h>
#include <stdlib.h>
#include <signal.h>
#include <errno.h>
#include <stdarg.h>
#include <string.h>
#include <sys/mman.h>
#include "user_util.h"
#include "kern_util.h"
#include "user.h"
#include "signal_user.h"
#include "signal_kern.h"
#include "sysdep/sigcontext.h"
#include "sigcontext.h"
void set_sigstack(void *sig_stack, int size)
{
stack_t stack = ((stack_t) { .ss_flags = 0,
.ss_sp = (__ptr_t) sig_stack,
.ss_size = size - sizeof(void *) });
if(sigaltstack(&stack, NULL) != 0)
panic("enabling signal stack failed, errno = %d\n", errno);
}
void set_handler(int sig, void (*handler)(int), int flags, ...)
{
struct sigaction action;
va_list ap;
int mask;
va_start(ap, flags);
action.sa_handler = handler;
sigemptyset(&action.sa_mask);
while((mask = va_arg(ap, int)) != -1){
sigaddset(&action.sa_mask, mask);
}
va_end(ap);
action.sa_flags = flags;
action.sa_restorer = NULL;
if(sigaction(sig, &action, NULL) < 0)
panic("sigaction failed");
}
int change_sig(int signal, int on)
{
sigset_t sigset, old;
sigemptyset(&sigset);
sigaddset(&sigset, signal);
sigprocmask(on ? SIG_UNBLOCK : SIG_BLOCK, &sigset, &old);
return(!sigismember(&old, signal));
}
/* Both here and in set/get_signal we don't touch SIGPROF, because we must not
* disable profiling; it's safe because the profiling code does not interact
* with the kernel code at all.*/
static void change_signals(int type)
{
sigset_t mask;
sigemptyset(&mask);
sigaddset(&mask, SIGVTALRM);
sigaddset(&mask, SIGALRM);
sigaddset(&mask, SIGIO);
if(sigprocmask(type, &mask, NULL) < 0)
panic("Failed to change signal mask - errno = %d", errno);
}
void block_signals(void)
{
change_signals(SIG_BLOCK);
}
void unblock_signals(void)
{
change_signals(SIG_UNBLOCK);
}
/* These are the asynchronous signals. SIGVTALRM and SIGARLM are handled
* together under SIGVTALRM_BIT. SIGPROF is excluded because we want to
* be able to profile all of UML, not just the non-critical sections. If
* profiling is not thread-safe, then that is not my problem. We can disable
* profiling when SMP is enabled in that case.
*/
#define SIGIO_BIT 0
#define SIGVTALRM_BIT 1
static int enable_mask(sigset_t *mask)
{
int sigs;
sigs = sigismember(mask, SIGIO) ? 0 : 1 << SIGIO_BIT;
sigs |= sigismember(mask, SIGVTALRM) ? 0 : 1 << SIGVTALRM_BIT;
sigs |= sigismember(mask, SIGALRM) ? 0 : 1 << SIGVTALRM_BIT;
return(sigs);
}
int get_signals(void)
{
sigset_t mask;
if(sigprocmask(SIG_SETMASK, NULL, &mask) < 0)
panic("Failed to get signal mask");
return(enable_mask(&mask));
}
int set_signals(int enable)
{
sigset_t mask;
int ret;
sigemptyset(&mask);
if(enable & (1 << SIGIO_BIT))
sigaddset(&mask, SIGIO);
if(enable & (1 << SIGVTALRM_BIT)){
sigaddset(&mask, SIGVTALRM);
sigaddset(&mask, SIGALRM);
}
/* This is safe - sigprocmask is guaranteed to copy locally the
* value of new_set, do his work and then, at the end, write to
* old_set.
*/
if(sigprocmask(SIG_UNBLOCK, &mask, &mask) < 0)
panic("Failed to enable signals");
ret = enable_mask(&mask);
sigemptyset(&mask);
if((enable & (1 << SIGIO_BIT)) == 0)
sigaddset(&mask, SIGIO);
if((enable & (1 << SIGVTALRM_BIT)) == 0){
sigaddset(&mask, SIGVTALRM);
sigaddset(&mask, SIGALRM);
}
if(sigprocmask(SIG_BLOCK, &mask, NULL) < 0)
panic("Failed to block signals");
return(ret);
}
/*
* Overrides for Emacs so that we follow Linus's tabbing style.
* Emacs will notice this stuff at the end of the file and automatically
* adjust the settings for this buffer only. This must remain at the end
* of the file.
* ---------------------------------------------------------------------------
* Local variables:
* c-file-style: "linux"
* End:
*/
|
