jcs.org
qemu with hax to log dma reads & writes
jcs.org/2018/11/12/vfio
linux-user: fix TARGET_NSIG and _NSIG uses
Valid signal numbers are between 1 (SIGHUP) and SIGRTMAX.
System includes define _NSIG to SIGRTMAX + 1, but
QEMU (like kernel) defines TARGET_NSIG to TARGET_SIGRTMAX.
Fix all the checks involving the signal range.
Signed-off-by: Laurent Vivier <laurent@vivier.eu>
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Tested-by: Taylor Simpson <tsimpson@quicinc.com>
Message-Id: <20200212125658.644558-4-laurent@vivier.eu>
+37
-15
+37
-15
linux-user/signal.c
+37
-15
linux-user/signal.c
···
30
30
static void host_signal_handler(int host_signum, siginfo_t *info,
31
31
void *puc);
32
32
33
+
34
+
/*
35
+
* System includes define _NSIG as SIGRTMAX + 1,
36
+
* but qemu (like the kernel) defines TARGET_NSIG as TARGET_SIGRTMAX
37
+
* and the first signal is SIGHUP defined as 1
38
+
* Signal number 0 is reserved for use as kill(pid, 0), to test whether
39
+
* a process exists without sending it a signal.
40
+
*/
41
+
QEMU_BUILD_BUG_ON(__SIGRTMAX + 1 != _NSIG);
33
42
static uint8_t host_to_target_signal_table[_NSIG] = {
34
43
[SIGHUP] = TARGET_SIGHUP,
35
44
[SIGINT] = TARGET_SIGINT,
···
67
76
[SIGSYS] = TARGET_SIGSYS,
68
77
/* next signals stay the same */
69
78
};
70
-
static uint8_t target_to_host_signal_table[_NSIG];
71
79
80
+
static uint8_t target_to_host_signal_table[TARGET_NSIG + 1];
81
+
82
+
/* valid sig is between 1 and _NSIG - 1 */
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83
int host_to_target_signal(int sig)
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84
{
74
-
if (sig < 0 || sig >= _NSIG)
85
+
if (sig < 1 || sig >= _NSIG) {
75
86
return sig;
87
+
}
76
88
return host_to_target_signal_table[sig];
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89
}
78
90
91
+
/* valid sig is between 1 and TARGET_NSIG */
79
92
int target_to_host_signal(int sig)
80
93
{
81
-
if (sig < 0 || sig >= _NSIG)
94
+
if (sig < 1 || sig > TARGET_NSIG) {
82
95
return sig;
96
+
}
83
97
return target_to_host_signal_table[sig];
84
98
}
85
99
···
100
114
void host_to_target_sigset_internal(target_sigset_t *d,
101
115
const sigset_t *s)
102
116
{
103
-
int i;
117
+
int host_sig, target_sig;
104
118
target_sigemptyset(d);
105
-
for (i = 1; i <= TARGET_NSIG; i++) {
106
-
if (sigismember(s, i)) {
107
-
target_sigaddset(d, host_to_target_signal(i));
119
+
for (host_sig = 1; host_sig < _NSIG; host_sig++) {
120
+
target_sig = host_to_target_signal(host_sig);
121
+
if (target_sig < 1 || target_sig > TARGET_NSIG) {
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+
continue;
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+
}
124
+
if (sigismember(s, host_sig)) {
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+
target_sigaddset(d, target_sig);
108
126
}
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127
}
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128
}
···
122
140
void target_to_host_sigset_internal(sigset_t *d,
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const target_sigset_t *s)
124
142
{
125
-
int i;
143
+
int host_sig, target_sig;
126
144
sigemptyset(d);
127
-
for (i = 1; i <= TARGET_NSIG; i++) {
128
-
if (target_sigismember(s, i)) {
129
-
sigaddset(d, target_to_host_signal(i));
145
+
for (target_sig = 1; target_sig <= TARGET_NSIG; target_sig++) {
146
+
host_sig = target_to_host_signal(target_sig);
147
+
if (host_sig < 1 || host_sig >= _NSIG) {
148
+
continue;
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+
}
150
+
if (target_sigismember(s, target_sig)) {
151
+
sigaddset(d, host_sig);
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152
}
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}
132
154
}
···
492
514
if (host_to_target_signal_table[host_sig] == 0) {
493
515
host_to_target_signal_table[host_sig] = host_sig;
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516
}
495
-
}
496
-
for (host_sig = 1; host_sig < _NSIG; host_sig++) {
497
517
target_sig = host_to_target_signal_table[host_sig];
498
-
target_to_host_signal_table[target_sig] = host_sig;
518
+
if (target_sig <= TARGET_NSIG) {
519
+
target_to_host_signal_table[target_sig] = host_sig;
520
+
}
499
521
}
500
522
}
501
523
···
518
540
act.sa_sigaction = host_signal_handler;
519
541
for(i = 1; i <= TARGET_NSIG; i++) {
520
542
#ifdef TARGET_GPROF
521
-
if (i == SIGPROF) {
543
+
if (i == TARGET_SIGPROF) {
522
544
continue;
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545
}
524
546
#endif