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
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
|
/** \ingroup rpmio
* \file rpmio/rpmsq.c
*/
#include "system.h"
#include <signal.h>
#include <sys/signal.h>
#include <errno.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <rpm/rpmsq.h>
#include <rpm/rpmlog.h>
#include "debug.h"
static __thread int disableInterruptSafety;
static __thread sigset_t rpmsqCaught;
static __thread sigset_t rpmsqActive;
typedef struct rpmsig_s * rpmsig;
static void rpmsqIgn(int signum, siginfo_t *info, void *context)
{
}
static void rpmsqTerm(int signum, siginfo_t *info, void *context)
{
if (info->si_pid == 0) {
rpmlog(RPMLOG_DEBUG,
"exiting on signal %d (killed by death, eh?)\n", signum);
} else {
int lvl = (signum == SIGPIPE) ? RPMLOG_DEBUG : RPMLOG_WARNING;
rpmlog(lvl,
_("exiting on signal %d from pid %d\n"), signum, info->si_pid);
}
/* exit 128 + signum for compatibility with bash(1) */
exit(128 + signum);
}
static struct rpmsig_s {
int signum;
rpmsqAction_t defhandler;
rpmsqAction_t handler;
siginfo_t siginfo;
struct sigaction oact;
} rpmsigTbl[] = {
{ SIGINT, rpmsqTerm, NULL },
{ SIGQUIT, rpmsqTerm, NULL },
{ SIGHUP, rpmsqTerm, NULL },
{ SIGTERM, rpmsqTerm, NULL },
{ SIGPIPE, rpmsqTerm, NULL },
{ -1, NULL, NULL },
};
static int rpmsigGet(int signum, struct rpmsig_s **sig)
{
for (rpmsig tbl = rpmsigTbl; tbl->signum >= 0; tbl++) {
if (tbl->signum == signum) {
*sig = tbl;
return 1;
}
}
return 0;
}
int rpmsqIsCaught(int signum)
{
return sigismember(&rpmsqCaught, signum);
}
static void rpmsqHandler(int signum, siginfo_t * info, void * context)
{
int save = errno;
if (sigismember(&rpmsqActive, signum)) {
if (!sigismember(&rpmsqCaught, signum)) {
rpmsig sig = NULL;
if (rpmsigGet(signum, &sig)) {
(void) sigaddset(&rpmsqCaught, signum);
memcpy(&sig->siginfo, info, sizeof(*info));
}
}
}
errno = save;
}
rpmsqAction_t rpmsqSetAction(int signum, rpmsqAction_t handler)
{
rpmsig sig = NULL;
rpmsqAction_t oh = RPMSQ_ERR;
if (rpmsigGet(signum, &sig)) {
oh = sig->handler;
sig->handler = (handler == RPMSQ_IGN) ? rpmsqIgn : handler;
}
return oh;
}
int rpmsqActivate(int state)
{
sigset_t newMask, oldMask;
if (disableInterruptSafety)
return 0;
(void) sigfillset(&newMask);
(void) pthread_sigmask(SIG_BLOCK, &newMask, &oldMask);
if (state) {
struct sigaction sa;
for (rpmsig tbl = rpmsigTbl; tbl->signum >= 0; tbl++) {
sigdelset(&rpmsqCaught, tbl->signum);
memset(&tbl->siginfo, 0, sizeof(tbl->siginfo));
/* XXX Don't set a signal handler if already SIG_IGN */
sigaction(tbl->signum, NULL, &tbl->oact);
if (tbl->oact.sa_handler == SIG_IGN)
continue;
sigemptyset (&sa.sa_mask);
sa.sa_flags = SA_SIGINFO;
sa.sa_sigaction = rpmsqHandler;
if (sigaction(tbl->signum, &sa, &tbl->oact) == 0)
sigaddset(&rpmsqActive, tbl->signum);
}
} else {
for (rpmsig tbl = rpmsigTbl; tbl->signum >= 0; tbl++) {
if (!sigismember(&rpmsqActive, tbl->signum))
continue;
if (sigaction(tbl->signum, &tbl->oact, NULL) == 0) {
sigdelset(&rpmsqActive, tbl->signum);
sigdelset(&rpmsqCaught, tbl->signum);
memset(&tbl->siginfo, 0, sizeof(tbl->siginfo));
}
}
}
pthread_sigmask(SIG_SETMASK, &oldMask, NULL);
return 0;
}
int rpmsqPoll(void)
{
sigset_t newMask, oldMask;
int n = 0;
/* block all signals while processing the queue */
(void) sigfillset(&newMask);
(void) pthread_sigmask(SIG_BLOCK, &newMask, &oldMask);
for (rpmsig tbl = rpmsigTbl; tbl->signum >= 0; tbl++) {
/* honor blocked signals in polling too */
if (sigismember(&oldMask, tbl->signum))
continue;
if (sigismember(&rpmsqCaught, tbl->signum)) {
rpmsqAction_t handler = (tbl->handler != NULL) ? tbl->handler :
tbl->defhandler;
/* delete signal before running handler to prevent recursing */
sigdelset(&rpmsqCaught, tbl->signum);
handler(tbl->signum, &tbl->siginfo, NULL);
memset(&tbl->siginfo, 0, sizeof(tbl->siginfo));
n++;
}
}
pthread_sigmask(SIG_SETMASK, &oldMask, NULL);
return n;
}
int rpmsqBlock(int op)
{
static __thread sigset_t oldMask;
static __thread int blocked = 0;
sigset_t newMask;
int ret = 0;
if (op == SIG_BLOCK) {
blocked++;
if (blocked == 1) {
sigfillset(&newMask);
sigdelset(&newMask, SIGABRT);
sigdelset(&newMask, SIGBUS);
sigdelset(&newMask, SIGFPE);
sigdelset(&newMask, SIGILL);
sigdelset(&newMask, SIGSEGV);
sigdelset(&newMask, SIGTSTP);
ret = pthread_sigmask(SIG_BLOCK, &newMask, &oldMask);
}
} else if (op == SIG_UNBLOCK) {
blocked--;
if (blocked == 0) {
ret = pthread_sigmask(SIG_SETMASK, &oldMask, NULL);
rpmsqPoll();
} else if (blocked < 0) {
blocked = 0;
ret = -1;
}
}
return ret;
}
/** \ingroup rpmio
*
* By default, librpm will trap various unix signals such as SIGINT and SIGTERM,
* in order to avoid process exit while locks are held or a transaction is being
* performed. However, there exist tools that operate on non-running roots (traditionally
* build systems such as mock), as well as deployment tools such as rpm-ostree.
*
* These tools are more robust against interruption - typically they
* will just throw away the partially constructed root. This function
* is designed for use by those tools, so an operator can happily
* press Control-C.
*
* It's recommended to call this once only at process startup if this
* behavior is desired (and to then avoid using librpm against "live"
* databases), because currently signal handlers will not be retroactively
* applied if a database is open.
*/
void rpmsqSetInterruptSafety(int on)
{
disableInterruptSafety = !on;
}
|
