-
Notifications
You must be signed in to change notification settings - Fork 1
/
signal.c
430 lines (367 loc) · 11.6 KB
/
signal.c
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
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
/* Copyright 2013-2024
* Kaz Kylheku <kaz@kylheku.com>
* Vancouver, Canada
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions are met:
*
* 1. Redistributions of source code must retain the above copyright notice,
* this list of conditions and the following disclaimer.
*
* 2. Redistributions in binary form must reproduce the above copyright notice,
* this list of conditions and the following disclaimer in the documentation
* and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
* AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE
* LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
* CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
* SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
* INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
* CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
* ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
* POSSIBILITY OF SUCH DAMAGE.
*/
#include <stdlib.h>
#include <string.h>
#include <errno.h>
#include <wchar.h>
#include <signal.h>
#include "config.h"
#if HAVE_SYS_TIME
#include <sys/time.h>
#endif
#if HAVE_VALGRIND
#include <valgrind/memcheck.h>
#endif
#include "lib.h"
#include "gc.h"
#include "sysif.h"
#include "signal.h"
#include "unwind.h"
#include "eval.h"
#include "txr.h"
#define MAX_SIG 32
volatile sig_atomic_t async_sig_enabled = 0;
static volatile sig_atomic_t interrupt_count = 0;
small_sigset_t sig_blocked_cache;
static val sig_lambda[MAX_SIG];
volatile unsigned long sig_deferred;
static int is_cpu_exception(int sig)
{
switch (sig) {
case SIGFPE: case SIGILL:
case SIGSEGV: case SIGBUS:
case SIGTRAP:
return 1;
default:
return 0;
}
}
static void sig_reload_cache(void)
{
sigset_t set;
if (sigprocmask(SIG_BLOCK, 0, &set) == 0)
memcpy(&sig_blocked_cache, &set, sizeof sig_blocked_cache);
}
static void sig_handler(int sig)
{
val lambda = sig_lambda[sig];
int gc = 0;
int as = 0;
int exc = is_cpu_exception(sig);
int ic = interrupt_count++;
int in_interrupt = ic > 0;
val *stack_lim = 0;
if (exc) {
gc = gc_state(0);
stack_lim = gc_stack_limit;
as = async_sig_enabled;
async_sig_enabled = 1;
gc_stack_limit = 0;
}
sig_reload_cache();
if (lambda) {
if (!in_interrupt && async_sig_enabled) {
uw_simple_catch_begin;
async_sig_enabled = 0;
if (gc_inprogress())
gc_cancel();
if (funcall2(lambda, num_fast(sig), t))
sig_deferred |= (1UL << sig);
uw_unwind {
interrupt_count = ic;
}
async_sig_enabled = 1;
uw_catch_end;
} else {
sig_deferred |= (1UL << sig);
}
}
if (exc) {
gc_stack_limit = stack_lim;
async_sig_enabled = as;
gc_state(gc);
}
interrupt_count = ic;
}
static val kill_wrap(val pid, val sig)
{
val self = lit("kill");
cnum p = c_num(pid, self), s = c_num(default_arg(sig, num_fast(SIGTERM)), self);
int res = kill(p, s);
if (opt_compat && opt_compat <= 114)
return num(res);
return tnil(res == 0);
}
static val raise_wrap(val sig)
{
val self = lit("raise");
int res = raise(c_num(sig, self));
return tnil(res == 0);
}
void sig_init(void)
{
int i;
for (i = 0; i < MAX_SIG; i++) {
/* t means SIG_DFL, which is what signals
* are before we manipulate them. */
sig_lambda[i] = t;
prot1(&sig_lambda[i]);
}
reg_varl(intern(lit("sig-hup"), user_package), num_fast(SIGHUP));
reg_varl(intern(lit("sig-int"), user_package), num_fast(SIGINT));
reg_varl(intern(lit("sig-quit"), user_package), num_fast(SIGQUIT));
reg_varl(intern(lit("sig-ill"), user_package), num_fast(SIGILL));
reg_varl(intern(lit("sig-trap"), user_package), num_fast(SIGTRAP));
reg_varl(intern(lit("sig-abrt"), user_package), num_fast(SIGABRT));
reg_varl(intern(lit("sig-bus"), user_package), num_fast(SIGBUS));
reg_varl(intern(lit("sig-fpe"), user_package), num_fast(SIGFPE));
reg_varl(intern(lit("sig-kill"), user_package), num_fast(SIGKILL));
reg_varl(intern(lit("sig-usr1"), user_package), num_fast(SIGUSR1));
reg_varl(intern(lit("sig-segv"), user_package), num_fast(SIGSEGV));
reg_varl(intern(lit("sig-usr2"), user_package), num_fast(SIGUSR2));
reg_varl(intern(lit("sig-pipe"), user_package), num_fast(SIGPIPE));
reg_varl(intern(lit("sig-alrm"), user_package), num_fast(SIGALRM));
reg_varl(intern(lit("sig-term"), user_package), num_fast(SIGTERM));
reg_varl(intern(lit("sig-chld"), user_package), num_fast(SIGCHLD));
reg_varl(intern(lit("sig-cont"), user_package), num_fast(SIGCONT));
reg_varl(intern(lit("sig-stop"), user_package), num_fast(SIGSTOP));
reg_varl(intern(lit("sig-tstp"), user_package), num_fast(SIGTSTP));
reg_varl(intern(lit("sig-ttin"), user_package), num_fast(SIGTTIN));
reg_varl(intern(lit("sig-ttou"), user_package), num_fast(SIGTTOU));
reg_varl(intern(lit("sig-urg"), user_package), num_fast(SIGURG));
reg_varl(intern(lit("sig-xcpu"), user_package), num_fast(SIGXCPU));
reg_varl(intern(lit("sig-xfsz"), user_package), num_fast(SIGXFSZ));
reg_varl(intern(lit("sig-vtalrm"), user_package), num_fast(SIGVTALRM));
reg_varl(intern(lit("sig-prof"), user_package), num_fast(SIGPROF));
#ifdef SIGPOLL
reg_varl(intern(lit("sig-poll"), user_package), num_fast(SIGPOLL));
#endif
reg_varl(intern(lit("sig-sys"), user_package), num_fast(SIGSYS));
#ifdef SIGWINCH
reg_varl(intern(lit("sig-winch"), user_package), num_fast(SIGWINCH));
#endif
#ifdef SIGIOT
reg_varl(intern(lit("sig-iot"), user_package), num_fast(SIGIOT));
#endif
#ifdef SIGSTKFLT
reg_varl(intern(lit("sig-stkflt"), user_package), num_fast(SIGSTKFLT));
#endif
#ifdef SIGIO
reg_varl(intern(lit("sig-io"), user_package), num_fast(SIGIO));
#endif
#ifdef SIGLOST
reg_varl(intern(lit("sig-lost"), user_package), num_fast(SIGLOST));
#endif
#ifdef SIGPWR
reg_varl(intern(lit("sig-pwr"), user_package), num_fast(SIGPWR));
#endif
#if HAVE_ITIMER
reg_varl(intern(lit("itimer-real"), user_package), num_fast(ITIMER_REAL));
reg_varl(intern(lit("itimer-virtual"), user_package), num_fast(ITIMER_VIRTUAL));
reg_varl(intern(lit("itimer-prof"), user_package), num_fast(ITIMER_PROF));
reg_fun(intern(lit("getitimer"), user_package), func_n1(getitimer_wrap));
reg_fun(intern(lit("setitimer"), user_package), func_n3(setitimer_wrap));
#endif
reg_fun(intern(lit("set-sig-handler"), user_package), func_n2(set_sig_handler));
reg_fun(intern(lit("get-sig-handler"), user_package), func_n1(get_sig_handler));
reg_fun(intern(lit("sig-check"), user_package), func_n0(sig_check));
reg_fun(intern(lit("kill"), user_package), func_n2o(kill_wrap, 1));
reg_fun(intern(lit("raise"), user_package), func_n1(raise_wrap));
sig_reload_cache();
}
#if HAVE_SIGALTSTACK
static mem_t *stack;
static int stack_refcount;
static void addref_alt_stack(void)
{
if (stack_refcount++ == 0) {
stack_t ss;
stack = chk_malloc(SIGSTKSZ);
ss.ss_sp = stack;
ss.ss_size = SIGSTKSZ;
ss.ss_flags = 0;
if (sigaltstack(&ss, NULL) == -1) {
free(stack);
stack = 0;
}
}
}
static void release_alt_stack(void)
{
if (--stack_refcount == 0) {
stack_t ss;
if (!stack)
return;
ss.ss_sp = stack;
ss.ss_size = SIGSTKSZ;
ss.ss_flags = SS_DISABLE;
if (sigaltstack(&ss, NULL) == -1)
return;
free(stack);
stack = 0;
}
}
#endif
static void small_sigfillset(small_sigset_t *ss)
{
ss->set = convert(unsigned int, -1);
}
val set_sig_handler(val signo, val lambda)
{
static struct sigaction blank;
val self = lit("set-sig-handler");
cnum sig = c_num(signo, self);
val old;
small_sigset_t block, saved;
small_sigfillset(&block);
sig_mask(SIG_BLOCK, &block, &saved);
if (sig < 0 || sig >= MAX_SIG)
uw_throwf(error_s, lit("~a: signal ~s out of range"), self, sig, nao);
old = sig_lambda[sig];
if (lambda != old) {
unsigned long mask = 1UL << sig;
if (lambda == nil || lambda == t) {
signal(sig, if3(lambda, SIG_DFL, SIG_IGN));
sig_deferred &= ~mask;
#if HAVE_SIGALTSTACK
if ((sig == SIGSEGV || sig == SIGBUS) && old != t && old != nil)
release_alt_stack();
#endif
} else {
struct sigaction sa = blank;
type_check(self, lambda, FUN);
sa.sa_flags = SA_RESTART;
sa.sa_handler = sig_handler;
sigfillset(&sa.sa_mask);
#if HAVE_SIGALTSTACK
if ((sig == SIGSEGV || sig == SIGBUS) && (old == t || old == nil)) {
addref_alt_stack();
sa.sa_flags |= SA_ONSTACK;
}
#endif
sigaction(sig, &sa, 0);
}
sig_lambda[sig] = lambda;
}
sig_mask(SIG_SETMASK, &saved, 0);
return old;
}
val get_sig_handler(val signo)
{
val self = lit("get-sig-handler");
cnum sig = c_num(signo, self);
if (sig < 0 || sig >= MAX_SIG)
uw_throwf(error_s, lit("~a: signal ~s out of range"), self, sig, nao);
return sig_lambda[sig];
}
val sig_check(void)
{
unsigned long sd;
int i;
if ((sd = sig_deferred) == 0)
return nil;
for (i = 0; i < MAX_SIG; i++) {
unsigned long mask = 1UL << i;
if ((sd & mask) != 0) {
sd &= ~mask;
sig_deferred = sd;
funcall2(sig_lambda[i], num_fast(i), nil);
}
}
return t;
}
int sig_mask(int how, const small_sigset_t *set, small_sigset_t *oldset)
{
small_sigset_t newset;
const small_sigset_t *pnew;
switch (how) {
case SIG_SETMASK:
pnew = set;
break;
case SIG_BLOCK:
pnew = &newset;
newset.set = sig_blocked_cache.set | set->set;
break;
case SIG_UNBLOCK:
pnew = &newset;
newset.set = sig_blocked_cache.set & ~set->set;
break;
default:
errno = EINVAL;
return -1;
}
if (sig_blocked_cache.set != pnew->set) {
static sigset_t blank;
sigset_t real_newset = blank, real_oldset;
int ret;
sig_blocked_cache = *pnew;
#if HAVE_VALGRIND
VALGRIND_MAKE_MEM_DEFINED(&real_oldset, sizeof real_oldset);
#endif
memcpy(&real_newset, &sig_blocked_cache, sizeof sig_blocked_cache);
ret = sigprocmask(SIG_SETMASK, &real_newset, &real_oldset);
if (ret == 0 && oldset != 0)
memcpy(oldset, &real_oldset, sizeof *oldset);
return ret;
}
if (oldset != 0)
*oldset = sig_blocked_cache;
return 0;
}
#if HAVE_ITIMER
static val tv_to_usec(val sec, val usec)
{
const val meg = num_fast(1000000);
return plus(mul(sec, meg), usec);
}
val getitimer_wrap(val which)
{
val self = lit("getitimer");
struct itimerval itv;
if (getitimer(c_num(which, self), &itv) < 0)
return nil;
return list(tv_to_usec(num_time(itv.it_interval.tv_sec), num(itv.it_interval.tv_usec)),
tv_to_usec(num_time(itv.it_value.tv_sec), num(itv.it_value.tv_usec)),
nao);
}
val setitimer_wrap(val which, val interval, val currval)
{
val self = lit("setitimer");
struct itimerval itn, itv;
const val meg = num_fast(1000000);
itn.it_interval.tv_sec = c_time(trunc(interval, meg), self);
itn.it_interval.tv_usec = c_num(mod(interval, meg), self);
itn.it_value.tv_sec = c_time(trunc(currval, meg), self);
itn.it_value.tv_usec = c_num(mod(currval, meg), self);
if (setitimer(c_num(which, self), &itn, &itv) < 0)
return nil;
return list(tv_to_usec(num_time(itv.it_interval.tv_sec), num(itv.it_interval.tv_usec)),
tv_to_usec(num_time(itv.it_value.tv_sec), num(itv.it_value.tv_usec)),
nao);
}
#endif