-
Notifications
You must be signed in to change notification settings - Fork 5.3k
/
signal.c
5880 lines (4988 loc) · 173 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
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
796
797
798
799
800
801
802
803
804
805
806
807
808
809
810
811
812
813
814
815
816
817
818
819
820
821
822
823
824
825
826
827
828
829
830
831
832
833
834
835
836
837
838
839
840
841
842
843
844
845
846
847
848
849
850
851
852
853
854
855
856
857
858
859
860
861
862
863
864
865
866
867
868
869
870
871
872
873
874
875
876
877
878
879
880
881
882
883
884
885
886
887
888
889
890
891
892
893
894
895
896
897
898
899
900
901
902
903
904
905
906
907
908
909
910
911
912
913
914
915
916
917
918
919
920
921
922
923
924
925
926
927
928
929
930
931
932
933
934
935
936
937
938
939
940
941
942
943
944
945
946
947
948
949
950
951
952
953
954
955
956
957
958
959
960
961
962
963
964
965
966
967
968
969
970
971
972
973
974
975
976
977
978
979
980
981
982
983
984
985
986
987
988
989
990
991
992
993
994
995
996
997
998
999
1000
/*
* Emulation of Linux signals
*
* Copyright (c) 2003 Fabrice Bellard
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, see <http://www.gnu.org/licenses/>.
*/
#include "qemu/osdep.h"
#include <sys/ucontext.h>
#include <sys/resource.h>
#include "qemu.h"
#include "qemu-common.h"
#include "target_signal.h"
#include "trace.h"
static struct target_sigaltstack target_sigaltstack_used = {
.ss_sp = 0,
.ss_size = 0,
.ss_flags = TARGET_SS_DISABLE,
};
static struct target_sigaction sigact_table[TARGET_NSIG];
static void host_signal_handler(int host_signum, siginfo_t *info,
void *puc);
static uint8_t host_to_target_signal_table[_NSIG] = {
[SIGHUP] = TARGET_SIGHUP,
[SIGINT] = TARGET_SIGINT,
[SIGQUIT] = TARGET_SIGQUIT,
[SIGILL] = TARGET_SIGILL,
[SIGTRAP] = TARGET_SIGTRAP,
[SIGABRT] = TARGET_SIGABRT,
/* [SIGIOT] = TARGET_SIGIOT,*/
[SIGBUS] = TARGET_SIGBUS,
[SIGFPE] = TARGET_SIGFPE,
[SIGKILL] = TARGET_SIGKILL,
[SIGUSR1] = TARGET_SIGUSR1,
[SIGSEGV] = TARGET_SIGSEGV,
[SIGUSR2] = TARGET_SIGUSR2,
[SIGPIPE] = TARGET_SIGPIPE,
[SIGALRM] = TARGET_SIGALRM,
[SIGTERM] = TARGET_SIGTERM,
#ifdef SIGSTKFLT
[SIGSTKFLT] = TARGET_SIGSTKFLT,
#endif
[SIGCHLD] = TARGET_SIGCHLD,
[SIGCONT] = TARGET_SIGCONT,
[SIGSTOP] = TARGET_SIGSTOP,
[SIGTSTP] = TARGET_SIGTSTP,
[SIGTTIN] = TARGET_SIGTTIN,
[SIGTTOU] = TARGET_SIGTTOU,
[SIGURG] = TARGET_SIGURG,
[SIGXCPU] = TARGET_SIGXCPU,
[SIGXFSZ] = TARGET_SIGXFSZ,
[SIGVTALRM] = TARGET_SIGVTALRM,
[SIGPROF] = TARGET_SIGPROF,
[SIGWINCH] = TARGET_SIGWINCH,
[SIGIO] = TARGET_SIGIO,
[SIGPWR] = TARGET_SIGPWR,
[SIGSYS] = TARGET_SIGSYS,
/* next signals stay the same */
/* Nasty hack: Reverse SIGRTMIN and SIGRTMAX to avoid overlap with
host libpthread signals. This assumes no one actually uses SIGRTMAX :-/
To fix this properly we need to do manual signal delivery multiplexed
over a single host signal. */
[__SIGRTMIN] = __SIGRTMAX,
[__SIGRTMAX] = __SIGRTMIN,
};
static uint8_t target_to_host_signal_table[_NSIG];
static inline int on_sig_stack(unsigned long sp)
{
return (sp - target_sigaltstack_used.ss_sp
< target_sigaltstack_used.ss_size);
}
static inline int sas_ss_flags(unsigned long sp)
{
return (target_sigaltstack_used.ss_size == 0 ? SS_DISABLE
: on_sig_stack(sp) ? SS_ONSTACK : 0);
}
int host_to_target_signal(int sig)
{
if (sig < 0 || sig >= _NSIG)
return sig;
return host_to_target_signal_table[sig];
}
int target_to_host_signal(int sig)
{
if (sig < 0 || sig >= _NSIG)
return sig;
return target_to_host_signal_table[sig];
}
static inline void target_sigemptyset(target_sigset_t *set)
{
memset(set, 0, sizeof(*set));
}
static inline void target_sigaddset(target_sigset_t *set, int signum)
{
signum--;
abi_ulong mask = (abi_ulong)1 << (signum % TARGET_NSIG_BPW);
set->sig[signum / TARGET_NSIG_BPW] |= mask;
}
static inline int target_sigismember(const target_sigset_t *set, int signum)
{
signum--;
abi_ulong mask = (abi_ulong)1 << (signum % TARGET_NSIG_BPW);
return ((set->sig[signum / TARGET_NSIG_BPW] & mask) != 0);
}
static void host_to_target_sigset_internal(target_sigset_t *d,
const sigset_t *s)
{
int i;
target_sigemptyset(d);
for (i = 1; i <= TARGET_NSIG; i++) {
if (sigismember(s, i)) {
target_sigaddset(d, host_to_target_signal(i));
}
}
}
void host_to_target_sigset(target_sigset_t *d, const sigset_t *s)
{
target_sigset_t d1;
int i;
host_to_target_sigset_internal(&d1, s);
for(i = 0;i < TARGET_NSIG_WORDS; i++)
d->sig[i] = tswapal(d1.sig[i]);
}
static void target_to_host_sigset_internal(sigset_t *d,
const target_sigset_t *s)
{
int i;
sigemptyset(d);
for (i = 1; i <= TARGET_NSIG; i++) {
if (target_sigismember(s, i)) {
sigaddset(d, target_to_host_signal(i));
}
}
}
void target_to_host_sigset(sigset_t *d, const target_sigset_t *s)
{
target_sigset_t s1;
int i;
for(i = 0;i < TARGET_NSIG_WORDS; i++)
s1.sig[i] = tswapal(s->sig[i]);
target_to_host_sigset_internal(d, &s1);
}
void host_to_target_old_sigset(abi_ulong *old_sigset,
const sigset_t *sigset)
{
target_sigset_t d;
host_to_target_sigset(&d, sigset);
*old_sigset = d.sig[0];
}
void target_to_host_old_sigset(sigset_t *sigset,
const abi_ulong *old_sigset)
{
target_sigset_t d;
int i;
d.sig[0] = *old_sigset;
for(i = 1;i < TARGET_NSIG_WORDS; i++)
d.sig[i] = 0;
target_to_host_sigset(sigset, &d);
}
int block_signals(void)
{
TaskState *ts = (TaskState *)thread_cpu->opaque;
sigset_t set;
int pending;
/* It's OK to block everything including SIGSEGV, because we won't
* run any further guest code before unblocking signals in
* process_pending_signals().
*/
sigfillset(&set);
sigprocmask(SIG_SETMASK, &set, 0);
pending = atomic_xchg(&ts->signal_pending, 1);
return pending;
}
/* Wrapper for sigprocmask function
* Emulates a sigprocmask in a safe way for the guest. Note that set and oldset
* are host signal set, not guest ones. Returns -TARGET_ERESTARTSYS if
* a signal was already pending and the syscall must be restarted, or
* 0 on success.
* If set is NULL, this is guaranteed not to fail.
*/
int do_sigprocmask(int how, const sigset_t *set, sigset_t *oldset)
{
TaskState *ts = (TaskState *)thread_cpu->opaque;
if (oldset) {
*oldset = ts->signal_mask;
}
if (set) {
int i;
if (block_signals()) {
return -TARGET_ERESTARTSYS;
}
switch (how) {
case SIG_BLOCK:
sigorset(&ts->signal_mask, &ts->signal_mask, set);
break;
case SIG_UNBLOCK:
for (i = 1; i <= NSIG; ++i) {
if (sigismember(set, i)) {
sigdelset(&ts->signal_mask, i);
}
}
break;
case SIG_SETMASK:
ts->signal_mask = *set;
break;
default:
g_assert_not_reached();
}
/* Silently ignore attempts to change blocking status of KILL or STOP */
sigdelset(&ts->signal_mask, SIGKILL);
sigdelset(&ts->signal_mask, SIGSTOP);
}
return 0;
}
#if !defined(TARGET_OPENRISC) && !defined(TARGET_UNICORE32) && \
!defined(TARGET_X86_64)
/* Just set the guest's signal mask to the specified value; the
* caller is assumed to have called block_signals() already.
*/
static void set_sigmask(const sigset_t *set)
{
TaskState *ts = (TaskState *)thread_cpu->opaque;
ts->signal_mask = *set;
}
#endif
/* siginfo conversion */
static inline void host_to_target_siginfo_noswap(target_siginfo_t *tinfo,
const siginfo_t *info)
{
int sig = host_to_target_signal(info->si_signo);
tinfo->si_signo = sig;
tinfo->si_errno = 0;
tinfo->si_code = info->si_code;
if (sig == TARGET_SIGILL || sig == TARGET_SIGFPE || sig == TARGET_SIGSEGV
|| sig == TARGET_SIGBUS || sig == TARGET_SIGTRAP) {
/* Should never come here, but who knows. The information for
the target is irrelevant. */
tinfo->_sifields._sigfault._addr = 0;
} else if (sig == TARGET_SIGIO) {
tinfo->_sifields._sigpoll._band = info->si_band;
tinfo->_sifields._sigpoll._fd = info->si_fd;
} else if (sig == TARGET_SIGCHLD) {
tinfo->_sifields._sigchld._pid = info->si_pid;
tinfo->_sifields._sigchld._uid = info->si_uid;
tinfo->_sifields._sigchld._status
= host_to_target_waitstatus(info->si_status);
tinfo->_sifields._sigchld._utime = info->si_utime;
tinfo->_sifields._sigchld._stime = info->si_stime;
} else if (sig >= TARGET_SIGRTMIN) {
tinfo->_sifields._rt._pid = info->si_pid;
tinfo->_sifields._rt._uid = info->si_uid;
/* XXX: potential problem if 64 bit */
tinfo->_sifields._rt._sigval.sival_ptr
= (abi_ulong)(unsigned long)info->si_value.sival_ptr;
}
}
static void tswap_siginfo(target_siginfo_t *tinfo,
const target_siginfo_t *info)
{
int sig = info->si_signo;
tinfo->si_signo = tswap32(sig);
tinfo->si_errno = tswap32(info->si_errno);
tinfo->si_code = tswap32(info->si_code);
if (sig == TARGET_SIGILL || sig == TARGET_SIGFPE || sig == TARGET_SIGSEGV
|| sig == TARGET_SIGBUS || sig == TARGET_SIGTRAP) {
tinfo->_sifields._sigfault._addr
= tswapal(info->_sifields._sigfault._addr);
} else if (sig == TARGET_SIGIO) {
tinfo->_sifields._sigpoll._band
= tswap32(info->_sifields._sigpoll._band);
tinfo->_sifields._sigpoll._fd = tswap32(info->_sifields._sigpoll._fd);
} else if (sig == TARGET_SIGCHLD) {
tinfo->_sifields._sigchld._pid
= tswap32(info->_sifields._sigchld._pid);
tinfo->_sifields._sigchld._uid
= tswap32(info->_sifields._sigchld._uid);
tinfo->_sifields._sigchld._status
= tswap32(info->_sifields._sigchld._status);
tinfo->_sifields._sigchld._utime
= tswapal(info->_sifields._sigchld._utime);
tinfo->_sifields._sigchld._stime
= tswapal(info->_sifields._sigchld._stime);
} else if (sig >= TARGET_SIGRTMIN) {
tinfo->_sifields._rt._pid = tswap32(info->_sifields._rt._pid);
tinfo->_sifields._rt._uid = tswap32(info->_sifields._rt._uid);
tinfo->_sifields._rt._sigval.sival_ptr
= tswapal(info->_sifields._rt._sigval.sival_ptr);
}
}
void host_to_target_siginfo(target_siginfo_t *tinfo, const siginfo_t *info)
{
host_to_target_siginfo_noswap(tinfo, info);
tswap_siginfo(tinfo, tinfo);
}
/* XXX: we support only POSIX RT signals are used. */
/* XXX: find a solution for 64 bit (additional malloced data is needed) */
void target_to_host_siginfo(siginfo_t *info, const target_siginfo_t *tinfo)
{
info->si_signo = tswap32(tinfo->si_signo);
info->si_errno = tswap32(tinfo->si_errno);
info->si_code = tswap32(tinfo->si_code);
info->si_pid = tswap32(tinfo->_sifields._rt._pid);
info->si_uid = tswap32(tinfo->_sifields._rt._uid);
info->si_value.sival_ptr =
(void *)(long)tswapal(tinfo->_sifields._rt._sigval.sival_ptr);
}
static int fatal_signal (int sig)
{
switch (sig) {
case TARGET_SIGCHLD:
case TARGET_SIGURG:
case TARGET_SIGWINCH:
/* Ignored by default. */
return 0;
case TARGET_SIGCONT:
case TARGET_SIGSTOP:
case TARGET_SIGTSTP:
case TARGET_SIGTTIN:
case TARGET_SIGTTOU:
/* Job control signals. */
return 0;
default:
return 1;
}
}
/* returns 1 if given signal should dump core if not handled */
static int core_dump_signal(int sig)
{
switch (sig) {
case TARGET_SIGABRT:
case TARGET_SIGFPE:
case TARGET_SIGILL:
case TARGET_SIGQUIT:
case TARGET_SIGSEGV:
case TARGET_SIGTRAP:
case TARGET_SIGBUS:
return (1);
default:
return (0);
}
}
void signal_init(void)
{
TaskState *ts = (TaskState *)thread_cpu->opaque;
struct sigaction act;
struct sigaction oact;
int i, j;
int host_sig;
/* generate signal conversion tables */
for(i = 1; i < _NSIG; i++) {
if (host_to_target_signal_table[i] == 0)
host_to_target_signal_table[i] = i;
}
for(i = 1; i < _NSIG; i++) {
j = host_to_target_signal_table[i];
target_to_host_signal_table[j] = i;
}
/* Set the signal mask from the host mask. */
sigprocmask(0, 0, &ts->signal_mask);
/* set all host signal handlers. ALL signals are blocked during
the handlers to serialize them. */
memset(sigact_table, 0, sizeof(sigact_table));
sigfillset(&act.sa_mask);
act.sa_flags = SA_SIGINFO;
act.sa_sigaction = host_signal_handler;
for(i = 1; i <= TARGET_NSIG; i++) {
host_sig = target_to_host_signal(i);
sigaction(host_sig, NULL, &oact);
if (oact.sa_sigaction == (void *)SIG_IGN) {
sigact_table[i - 1]._sa_handler = TARGET_SIG_IGN;
} else if (oact.sa_sigaction == (void *)SIG_DFL) {
sigact_table[i - 1]._sa_handler = TARGET_SIG_DFL;
}
/* If there's already a handler installed then something has
gone horribly wrong, so don't even try to handle that case. */
/* Install some handlers for our own use. We need at least
SIGSEGV and SIGBUS, to detect exceptions. We can not just
trap all signals because it affects syscall interrupt
behavior. But do trap all default-fatal signals. */
if (fatal_signal (i))
sigaction(host_sig, &act, NULL);
}
}
/* abort execution with signal */
static void QEMU_NORETURN force_sig(int target_sig)
{
CPUState *cpu = thread_cpu;
CPUArchState *env = cpu->env_ptr;
TaskState *ts = (TaskState *)cpu->opaque;
int host_sig, core_dumped = 0;
struct sigaction act;
host_sig = target_to_host_signal(target_sig);
trace_user_force_sig(env, target_sig, host_sig);
gdb_signalled(env, target_sig);
/* dump core if supported by target binary format */
if (core_dump_signal(target_sig) && (ts->bprm->core_dump != NULL)) {
stop_all_tasks();
core_dumped =
((*ts->bprm->core_dump)(target_sig, env) == 0);
}
if (core_dumped) {
/* we already dumped the core of target process, we don't want
* a coredump of qemu itself */
struct rlimit nodump;
getrlimit(RLIMIT_CORE, &nodump);
nodump.rlim_cur=0;
setrlimit(RLIMIT_CORE, &nodump);
(void) fprintf(stderr, "qemu: uncaught target signal %d (%s) - %s\n",
target_sig, strsignal(host_sig), "core dumped" );
}
/* The proper exit code for dying from an uncaught signal is
* -<signal>. The kernel doesn't allow exit() or _exit() to pass
* a negative value. To get the proper exit code we need to
* actually die from an uncaught signal. Here the default signal
* handler is installed, we send ourself a signal and we wait for
* it to arrive. */
sigfillset(&act.sa_mask);
act.sa_handler = SIG_DFL;
act.sa_flags = 0;
sigaction(host_sig, &act, NULL);
/* For some reason raise(host_sig) doesn't send the signal when
* statically linked on x86-64. */
kill(getpid(), host_sig);
/* Make sure the signal isn't masked (just reuse the mask inside
of act) */
sigdelset(&act.sa_mask, host_sig);
sigsuspend(&act.sa_mask);
/* unreachable */
abort();
}
/* queue a signal so that it will be send to the virtual CPU as soon
as possible */
int queue_signal(CPUArchState *env, int sig, target_siginfo_t *info)
{
CPUState *cpu = ENV_GET_CPU(env);
TaskState *ts = cpu->opaque;
trace_user_queue_signal(env, sig);
ts->sync_signal.info = *info;
ts->sync_signal.pending = sig;
/* signal that a new signal is pending */
atomic_set(&ts->signal_pending, 1);
return 1; /* indicates that the signal was queued */
}
#ifndef HAVE_SAFE_SYSCALL
static inline void rewind_if_in_safe_syscall(void *puc)
{
/* Default version: never rewind */
}
#endif
static void host_signal_handler(int host_signum, siginfo_t *info,
void *puc)
{
CPUArchState *env = thread_cpu->env_ptr;
CPUState *cpu = ENV_GET_CPU(env);
TaskState *ts = cpu->opaque;
int sig;
target_siginfo_t tinfo;
ucontext_t *uc = puc;
struct emulated_sigtable *k;
/* the CPU emulator uses some host signals to detect exceptions,
we forward to it some signals */
if ((host_signum == SIGSEGV || host_signum == SIGBUS)
&& info->si_code > 0) {
if (cpu_signal_handler(host_signum, info, puc))
return;
}
/* get target signal number */
sig = host_to_target_signal(host_signum);
if (sig < 1 || sig > TARGET_NSIG)
return;
trace_user_host_signal(env, host_signum, sig);
rewind_if_in_safe_syscall(puc);
host_to_target_siginfo_noswap(&tinfo, info);
k = &ts->sigtab[sig - 1];
k->info = tinfo;
k->pending = sig;
ts->signal_pending = 1;
/* Block host signals until target signal handler entered. We
* can't block SIGSEGV or SIGBUS while we're executing guest
* code in case the guest code provokes one in the window between
* now and it getting out to the main loop. Signals will be
* unblocked again in process_pending_signals().
*/
sigfillset(&uc->uc_sigmask);
sigdelset(&uc->uc_sigmask, SIGSEGV);
sigdelset(&uc->uc_sigmask, SIGBUS);
/* interrupt the virtual CPU as soon as possible */
cpu_exit(thread_cpu);
}
/* do_sigaltstack() returns target values and errnos. */
/* compare linux/kernel/signal.c:do_sigaltstack() */
abi_long do_sigaltstack(abi_ulong uss_addr, abi_ulong uoss_addr, abi_ulong sp)
{
int ret;
struct target_sigaltstack oss;
/* XXX: test errors */
if(uoss_addr)
{
__put_user(target_sigaltstack_used.ss_sp, &oss.ss_sp);
__put_user(target_sigaltstack_used.ss_size, &oss.ss_size);
__put_user(sas_ss_flags(sp), &oss.ss_flags);
}
if(uss_addr)
{
struct target_sigaltstack *uss;
struct target_sigaltstack ss;
size_t minstacksize = TARGET_MINSIGSTKSZ;
#if defined(TARGET_PPC64)
/* ELF V2 for PPC64 has a 4K minimum stack size for signal handlers */
struct image_info *image = ((TaskState *)thread_cpu->opaque)->info;
if (get_ppc64_abi(image) > 1) {
minstacksize = 4096;
}
#endif
ret = -TARGET_EFAULT;
if (!lock_user_struct(VERIFY_READ, uss, uss_addr, 1)) {
goto out;
}
__get_user(ss.ss_sp, &uss->ss_sp);
__get_user(ss.ss_size, &uss->ss_size);
__get_user(ss.ss_flags, &uss->ss_flags);
unlock_user_struct(uss, uss_addr, 0);
ret = -TARGET_EPERM;
if (on_sig_stack(sp))
goto out;
ret = -TARGET_EINVAL;
if (ss.ss_flags != TARGET_SS_DISABLE
&& ss.ss_flags != TARGET_SS_ONSTACK
&& ss.ss_flags != 0)
goto out;
if (ss.ss_flags == TARGET_SS_DISABLE) {
ss.ss_size = 0;
ss.ss_sp = 0;
} else {
ret = -TARGET_ENOMEM;
if (ss.ss_size < minstacksize) {
goto out;
}
}
target_sigaltstack_used.ss_sp = ss.ss_sp;
target_sigaltstack_used.ss_size = ss.ss_size;
}
if (uoss_addr) {
ret = -TARGET_EFAULT;
if (copy_to_user(uoss_addr, &oss, sizeof(oss)))
goto out;
}
ret = 0;
out:
return ret;
}
/* do_sigaction() return host values and errnos */
int do_sigaction(int sig, const struct target_sigaction *act,
struct target_sigaction *oact)
{
struct target_sigaction *k;
struct sigaction act1;
int host_sig;
int ret = 0;
if (sig < 1 || sig > TARGET_NSIG || sig == TARGET_SIGKILL || sig == TARGET_SIGSTOP)
return -EINVAL;
k = &sigact_table[sig - 1];
if (oact) {
__put_user(k->_sa_handler, &oact->_sa_handler);
__put_user(k->sa_flags, &oact->sa_flags);
#if !defined(TARGET_MIPS)
__put_user(k->sa_restorer, &oact->sa_restorer);
#endif
/* Not swapped. */
oact->sa_mask = k->sa_mask;
}
if (act) {
/* FIXME: This is not threadsafe. */
__get_user(k->_sa_handler, &act->_sa_handler);
__get_user(k->sa_flags, &act->sa_flags);
#if !defined(TARGET_MIPS)
__get_user(k->sa_restorer, &act->sa_restorer);
#endif
/* To be swapped in target_to_host_sigset. */
k->sa_mask = act->sa_mask;
/* we update the host linux signal state */
host_sig = target_to_host_signal(sig);
if (host_sig != SIGSEGV && host_sig != SIGBUS) {
sigfillset(&act1.sa_mask);
act1.sa_flags = SA_SIGINFO;
if (k->sa_flags & TARGET_SA_RESTART)
act1.sa_flags |= SA_RESTART;
/* NOTE: it is important to update the host kernel signal
ignore state to avoid getting unexpected interrupted
syscalls */
if (k->_sa_handler == TARGET_SIG_IGN) {
act1.sa_sigaction = (void *)SIG_IGN;
} else if (k->_sa_handler == TARGET_SIG_DFL) {
if (fatal_signal (sig))
act1.sa_sigaction = host_signal_handler;
else
act1.sa_sigaction = (void *)SIG_DFL;
} else {
act1.sa_sigaction = host_signal_handler;
}
ret = sigaction(host_sig, &act1, NULL);
}
}
return ret;
}
#if defined(TARGET_I386) && TARGET_ABI_BITS == 32
/* from the Linux kernel */
struct target_fpreg {
uint16_t significand[4];
uint16_t exponent;
};
struct target_fpxreg {
uint16_t significand[4];
uint16_t exponent;
uint16_t padding[3];
};
struct target_xmmreg {
abi_ulong element[4];
};
struct target_fpstate {
/* Regular FPU environment */
abi_ulong cw;
abi_ulong sw;
abi_ulong tag;
abi_ulong ipoff;
abi_ulong cssel;
abi_ulong dataoff;
abi_ulong datasel;
struct target_fpreg _st[8];
uint16_t status;
uint16_t magic; /* 0xffff = regular FPU data only */
/* FXSR FPU environment */
abi_ulong _fxsr_env[6]; /* FXSR FPU env is ignored */
abi_ulong mxcsr;
abi_ulong reserved;
struct target_fpxreg _fxsr_st[8]; /* FXSR FPU reg data is ignored */
struct target_xmmreg _xmm[8];
abi_ulong padding[56];
};
#define X86_FXSR_MAGIC 0x0000
struct target_sigcontext {
uint16_t gs, __gsh;
uint16_t fs, __fsh;
uint16_t es, __esh;
uint16_t ds, __dsh;
abi_ulong edi;
abi_ulong esi;
abi_ulong ebp;
abi_ulong esp;
abi_ulong ebx;
abi_ulong edx;
abi_ulong ecx;
abi_ulong eax;
abi_ulong trapno;
abi_ulong err;
abi_ulong eip;
uint16_t cs, __csh;
abi_ulong eflags;
abi_ulong esp_at_signal;
uint16_t ss, __ssh;
abi_ulong fpstate; /* pointer */
abi_ulong oldmask;
abi_ulong cr2;
};
struct target_ucontext {
abi_ulong tuc_flags;
abi_ulong tuc_link;
target_stack_t tuc_stack;
struct target_sigcontext tuc_mcontext;
target_sigset_t tuc_sigmask; /* mask last for extensibility */
};
struct sigframe
{
abi_ulong pretcode;
int sig;
struct target_sigcontext sc;
struct target_fpstate fpstate;
abi_ulong extramask[TARGET_NSIG_WORDS-1];
char retcode[8];
};
struct rt_sigframe
{
abi_ulong pretcode;
int sig;
abi_ulong pinfo;
abi_ulong puc;
struct target_siginfo info;
struct target_ucontext uc;
struct target_fpstate fpstate;
char retcode[8];
};
/*
* Set up a signal frame.
*/
/* XXX: save x87 state */
static void setup_sigcontext(struct target_sigcontext *sc,
struct target_fpstate *fpstate, CPUX86State *env, abi_ulong mask,
abi_ulong fpstate_addr)
{
CPUState *cs = CPU(x86_env_get_cpu(env));
uint16_t magic;
/* already locked in setup_frame() */
__put_user(env->segs[R_GS].selector, (unsigned int *)&sc->gs);
__put_user(env->segs[R_FS].selector, (unsigned int *)&sc->fs);
__put_user(env->segs[R_ES].selector, (unsigned int *)&sc->es);
__put_user(env->segs[R_DS].selector, (unsigned int *)&sc->ds);
__put_user(env->regs[R_EDI], &sc->edi);
__put_user(env->regs[R_ESI], &sc->esi);
__put_user(env->regs[R_EBP], &sc->ebp);
__put_user(env->regs[R_ESP], &sc->esp);
__put_user(env->regs[R_EBX], &sc->ebx);
__put_user(env->regs[R_EDX], &sc->edx);
__put_user(env->regs[R_ECX], &sc->ecx);
__put_user(env->regs[R_EAX], &sc->eax);
__put_user(cs->exception_index, &sc->trapno);
__put_user(env->error_code, &sc->err);
__put_user(env->eip, &sc->eip);
__put_user(env->segs[R_CS].selector, (unsigned int *)&sc->cs);
__put_user(env->eflags, &sc->eflags);
__put_user(env->regs[R_ESP], &sc->esp_at_signal);
__put_user(env->segs[R_SS].selector, (unsigned int *)&sc->ss);
cpu_x86_fsave(env, fpstate_addr, 1);
fpstate->status = fpstate->sw;
magic = 0xffff;
__put_user(magic, &fpstate->magic);
__put_user(fpstate_addr, &sc->fpstate);
/* non-iBCS2 extensions.. */
__put_user(mask, &sc->oldmask);
__put_user(env->cr[2], &sc->cr2);
}
/*
* Determine which stack to use..
*/
static inline abi_ulong
get_sigframe(struct target_sigaction *ka, CPUX86State *env, size_t frame_size)
{
unsigned long esp;
/* Default to using normal stack */
esp = env->regs[R_ESP];
/* This is the X/Open sanctioned signal stack switching. */
if (ka->sa_flags & TARGET_SA_ONSTACK) {
if (sas_ss_flags(esp) == 0) {
esp = target_sigaltstack_used.ss_sp + target_sigaltstack_used.ss_size;
}
} else {
/* This is the legacy signal stack switching. */
if ((env->segs[R_SS].selector & 0xffff) != __USER_DS &&
!(ka->sa_flags & TARGET_SA_RESTORER) &&
ka->sa_restorer) {
esp = (unsigned long) ka->sa_restorer;
}
}
return (esp - frame_size) & -8ul;
}
/* compare linux/arch/i386/kernel/signal.c:setup_frame() */
static void setup_frame(int sig, struct target_sigaction *ka,
target_sigset_t *set, CPUX86State *env)
{
abi_ulong frame_addr;
struct sigframe *frame;
int i;
frame_addr = get_sigframe(ka, env, sizeof(*frame));
trace_user_setup_frame(env, frame_addr);
if (!lock_user_struct(VERIFY_WRITE, frame, frame_addr, 0))
goto give_sigsegv;
__put_user(sig, &frame->sig);
setup_sigcontext(&frame->sc, &frame->fpstate, env, set->sig[0],
frame_addr + offsetof(struct sigframe, fpstate));
for(i = 1; i < TARGET_NSIG_WORDS; i++) {
__put_user(set->sig[i], &frame->extramask[i - 1]);
}
/* Set up to return from userspace. If provided, use a stub
already in userspace. */
if (ka->sa_flags & TARGET_SA_RESTORER) {
__put_user(ka->sa_restorer, &frame->pretcode);
} else {
uint16_t val16;
abi_ulong retcode_addr;
retcode_addr = frame_addr + offsetof(struct sigframe, retcode);
__put_user(retcode_addr, &frame->pretcode);
/* This is popl %eax ; movl $,%eax ; int $0x80 */
val16 = 0xb858;
__put_user(val16, (uint16_t *)(frame->retcode+0));
__put_user(TARGET_NR_sigreturn, (int *)(frame->retcode+2));
val16 = 0x80cd;
__put_user(val16, (uint16_t *)(frame->retcode+6));
}
/* Set up registers for signal handler */
env->regs[R_ESP] = frame_addr;
env->eip = ka->_sa_handler;
cpu_x86_load_seg(env, R_DS, __USER_DS);
cpu_x86_load_seg(env, R_ES, __USER_DS);
cpu_x86_load_seg(env, R_SS, __USER_DS);
cpu_x86_load_seg(env, R_CS, __USER_CS);
env->eflags &= ~TF_MASK;
unlock_user_struct(frame, frame_addr, 1);
return;
give_sigsegv:
if (sig == TARGET_SIGSEGV) {
ka->_sa_handler = TARGET_SIG_DFL;
}
force_sig(TARGET_SIGSEGV /* , current */);
}
/* compare linux/arch/i386/kernel/signal.c:setup_rt_frame() */
static void setup_rt_frame(int sig, struct target_sigaction *ka,
target_siginfo_t *info,
target_sigset_t *set, CPUX86State *env)
{
abi_ulong frame_addr, addr;
struct rt_sigframe *frame;
int i;
frame_addr = get_sigframe(ka, env, sizeof(*frame));
trace_user_setup_rt_frame(env, frame_addr);
if (!lock_user_struct(VERIFY_WRITE, frame, frame_addr, 0))
goto give_sigsegv;
__put_user(sig, &frame->sig);
addr = frame_addr + offsetof(struct rt_sigframe, info);
__put_user(addr, &frame->pinfo);
addr = frame_addr + offsetof(struct rt_sigframe, uc);
__put_user(addr, &frame->puc);
tswap_siginfo(&frame->info, info);
/* Create the ucontext. */
__put_user(0, &frame->uc.tuc_flags);
__put_user(0, &frame->uc.tuc_link);
__put_user(target_sigaltstack_used.ss_sp, &frame->uc.tuc_stack.ss_sp);
__put_user(sas_ss_flags(get_sp_from_cpustate(env)),
&frame->uc.tuc_stack.ss_flags);
__put_user(target_sigaltstack_used.ss_size,
&frame->uc.tuc_stack.ss_size);
setup_sigcontext(&frame->uc.tuc_mcontext, &frame->fpstate, env,
set->sig[0], frame_addr + offsetof(struct rt_sigframe, fpstate));
for(i = 0; i < TARGET_NSIG_WORDS; i++) {
__put_user(set->sig[i], &frame->uc.tuc_sigmask.sig[i]);
}
/* Set up to return from userspace. If provided, use a stub
already in userspace. */
if (ka->sa_flags & TARGET_SA_RESTORER) {
__put_user(ka->sa_restorer, &frame->pretcode);
} else {
uint16_t val16;
addr = frame_addr + offsetof(struct rt_sigframe, retcode);
__put_user(addr, &frame->pretcode);
/* This is movl $,%eax ; int $0x80 */
__put_user(0xb8, (char *)(frame->retcode+0));
__put_user(TARGET_NR_rt_sigreturn, (int *)(frame->retcode+1));
val16 = 0x80cd;
__put_user(val16, (uint16_t *)(frame->retcode+5));
}
/* Set up registers for signal handler */
env->regs[R_ESP] = frame_addr;
env->eip = ka->_sa_handler;
cpu_x86_load_seg(env, R_DS, __USER_DS);
cpu_x86_load_seg(env, R_ES, __USER_DS);
cpu_x86_load_seg(env, R_SS, __USER_DS);
cpu_x86_load_seg(env, R_CS, __USER_CS);
env->eflags &= ~TF_MASK;
unlock_user_struct(frame, frame_addr, 1);
return;
give_sigsegv:
if (sig == TARGET_SIGSEGV) {
ka->_sa_handler = TARGET_SIG_DFL;