aboutsummaryrefslogtreecommitdiff
path: root/linux-user/signal.c
blob: 945dd14e0c42e7276700fa780f306d6c2095f331 (plain)
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
1001
1002
1003
1004
1005
1006
1007
1008
1009
1010
1011
1012
1013
1014
1015
1016
1017
1018
1019
1020
1021
1022
1023
1024
1025
1026
1027
1028
1029
1030
1031
1032
1033
1034
1035
1036
1037
1038
1039
1040
1041
1042
1043
1044
1045
1046
1047
1048
1049
1050
1051
1052
1053
1054
1055
1056
1057
1058
1059
1060
1061
1062
1063
1064
1065
1066
1067
1068
1069
1070
1071
1072
1073
1074
1075
1076
1077
1078
1079
1080
1081
1082
1083
1084
1085
1086
1087
1088
1089
1090
1091
1092
1093
1094
1095
1096
1097
1098
1099
1100
1101
1102
1103
1104
1105
1106
1107
1108
1109
1110
1111
1112
1113
1114
1115
1116
1117
1118
1119
1120
1121
1122
1123
1124
1125
1126
1127
1128
1129
1130
1131
1132
1133
1134
1135
1136
1137
1138
1139
1140
1141
1142
1143
1144
1145
1146
1147
1148
1149
1150
1151
1152
1153
1154
1155
1156
1157
1158
1159
1160
1161
1162
1163
1164
1165
1166
1167
1168
1169
1170
1171
1172
1173
1174
1175
1176
1177
1178
1179
1180
1181
1182
1183
1184
1185
1186
1187
1188
1189
1190
1191
1192
1193
1194
1195
1196
1197
1198
1199
1200
1201
1202
1203
1204
1205
1206
1207
1208
1209
1210
1211
1212
1213
1214
1215
1216
1217
1218
1219
1220
1221
1222
1223
1224
1225
1226
1227
1228
1229
1230
1231
1232
1233
1234
1235
1236
1237
1238
1239
1240
1241
1242
1243
1244
1245
1246
1247
1248
1249
1250
1251
1252
1253
1254
1255
1256
1257
1258
1259
1260
1261
1262
1263
1264
1265
1266
1267
1268
1269
1270
1271
1272
1273
1274
1275
1276
1277
1278
1279
1280
1281
1282
1283
1284
1285
1286
1287
1288
1289
1290
1291
1292
1293
1294
1295
1296
1297
1298
1299
1300
1301
1302
1303
1304
1305
1306
1307
1308
1309
1310
1311
1312
1313
1314
1315
1316
1317
1318
1319
1320
1321
1322
1323
1324
1325
1326
1327
1328
1329
1330
1331
1332
1333
1334
1335
1336
1337
1338
1339
1340
1341
1342
1343
1344
1345
1346
1347
1348
1349
1350
1351
1352
1353
1354
1355
1356
1357
1358
1359
1360
1361
1362
1363
1364
1365
1366
1367
1368
1369
1370
1371
1372
1373
1374
1375
1376
1377
1378
1379
1380
1381
1382
1383
1384
1385
1386
1387
1388
1389
1390
1391
1392
1393
1394
1395
1396
1397
1398
1399
1400
1401
1402
1403
1404
1405
1406
1407
1408
1409
1410
1411
1412
1413
1414
1415
1416
1417
1418
1419
1420
1421
1422
1423
1424
1425
1426
1427
1428
1429
1430
1431
1432
1433
1434
1435
1436
1437
1438
1439
1440
1441
1442
1443
1444
1445
1446
1447
1448
1449
1450
1451
1452
1453
1454
1455
1456
1457
1458
1459
1460
1461
1462
1463
1464
1465
1466
1467
1468
1469
1470
1471
1472
1473
1474
1475
1476
1477
1478
1479
1480
1481
1482
1483
1484
1485
1486
1487
1488
1489
1490
1491
1492
1493
1494
1495
1496
1497
1498
1499
1500
1501
1502
1503
1504
1505
1506
1507
1508
1509
1510
1511
1512
1513
1514
1515
1516
1517
1518
1519
1520
1521
1522
1523
1524
1525
1526
1527
1528
1529
1530
1531
1532
1533
1534
1535
1536
1537
1538
1539
1540
1541
1542
1543
1544
1545
1546
1547
1548
1549
1550
1551
1552
1553
1554
1555
1556
1557
1558
1559
1560
1561
1562
1563
1564
1565
1566
1567
1568
1569
1570
1571
1572
1573
1574
1575
1576
1577
1578
1579
1580
1581
1582
1583
1584
1585
1586
1587
1588
1589
1590
1591
1592
1593
1594
1595
1596
1597
1598
1599
1600
1601
1602
1603
1604
1605
1606
1607
1608
1609
1610
1611
1612
1613
1614
1615
1616
1617
1618
1619
1620
1621
1622
1623
1624
1625
1626
1627
1628
1629
1630
1631
1632
1633
1634
1635
1636
1637
1638
1639
1640
1641
1642
1643
1644
1645
1646
1647
1648
1649
1650
1651
1652
1653
1654
1655
1656
1657
1658
1659
1660
1661
1662
1663
1664
1665
1666
1667
1668
1669
1670
1671
1672
1673
1674
1675
1676
1677
1678
1679
1680
1681
1682
1683
1684
1685
1686
1687
1688
1689
1690
1691
1692
1693
1694
1695
1696
1697
1698
1699
1700
1701
1702
1703
1704
1705
1706
1707
1708
1709
1710
1711
1712
1713
1714
1715
1716
1717
1718
1719
1720
1721
1722
1723
1724
1725
1726
1727
1728
1729
1730
1731
1732
1733
1734
1735
1736
1737
1738
1739
1740
1741
1742
1743
1744
1745
1746
1747
1748
1749
1750
1751
1752
1753
1754
1755
1756
1757
1758
1759
1760
1761
1762
1763
1764
1765
1766
1767
1768
1769
1770
1771
1772
1773
1774
1775
1776
1777
1778
1779
1780
1781
1782
1783
1784
1785
1786
1787
1788
1789
1790
1791
1792
1793
1794
1795
1796
1797
1798
1799
1800
1801
1802
1803
1804
1805
1806
1807
1808
1809
1810
1811
1812
1813
1814
1815
1816
1817
1818
1819
1820
1821
1822
1823
1824
1825
1826
1827
1828
1829
1830
1831
1832
1833
1834
1835
1836
1837
1838
1839
1840
1841
1842
1843
1844
1845
1846
1847
1848
1849
1850
1851
1852
1853
1854
1855
1856
1857
1858
1859
1860
1861
1862
1863
1864
1865
1866
1867
1868
1869
1870
1871
1872
1873
1874
1875
1876
1877
1878
1879
1880
1881
1882
1883
1884
1885
1886
1887
1888
1889
1890
1891
1892
1893
1894
1895
1896
1897
1898
1899
1900
1901
1902
1903
1904
1905
1906
1907
1908
1909
1910
1911
1912
1913
1914
1915
1916
1917
1918
1919
1920
1921
1922
1923
1924
1925
1926
1927
1928
1929
1930
1931
1932
1933
1934
1935
1936
1937
1938
1939
1940
1941
1942
1943
1944
1945
1946
1947
1948
1949
1950
1951
1952
1953
1954
1955
1956
1957
1958
1959
1960
1961
1962
1963
1964
1965
1966
1967
1968
1969
1970
1971
1972
1973
1974
1975
1976
1977
1978
1979
1980
1981
1982
1983
1984
1985
1986
1987
1988
1989
1990
1991
1992
1993
1994
1995
1996
1997
1998
1999
2000
2001
2002
2003
2004
2005
2006
2007
2008
2009
2010
2011
2012
2013
2014
2015
2016
2017
2018
2019
2020
2021
2022
2023
2024
2025
2026
2027
2028
2029
2030
2031
2032
2033
2034
2035
2036
2037
2038
2039
2040
2041
2042
2043
2044
2045
2046
2047
2048
2049
2050
2051
2052
2053
2054
2055
2056
2057
2058
2059
2060
2061
2062
2063
2064
2065
2066
2067
2068
2069
2070
2071
2072
2073
2074
2075
2076
2077
2078
2079
2080
2081
2082
2083
2084
2085
2086
2087
2088
2089
2090
2091
2092
2093
2094
2095
2096
2097
2098
2099
2100
2101
2102
2103
2104
2105
2106
2107
2108
2109
2110
2111
2112
2113
2114
2115
2116
2117
2118
2119
2120
2121
2122
2123
2124
2125
2126
2127
2128
2129
2130
2131
2132
2133
2134
2135
2136
2137
2138
2139
2140
2141
2142
/*
 *  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, write to the Free Software
 *  Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
 */
#include <stdlib.h>
#include <stdio.h>
#include <string.h>
#include <stdarg.h>
#include <unistd.h>
#include <signal.h>
#include <errno.h>
#include <sys/ucontext.h>

#include "target_signal.h"
#include "qemu.h"

//#define DEBUG_SIGNAL

#define MAX_SIGQUEUE_SIZE 1024

struct sigqueue {
    struct sigqueue *next;
    target_siginfo_t info;
};

struct emulated_sigaction {
    struct target_sigaction sa;
    int pending; /* true if signal is pending */
    struct sigqueue *first;
    struct sigqueue info; /* in order to always have memory for the
                             first signal, we put it here */
};

struct target_sigaltstack target_sigaltstack_used = {
    .ss_sp = 0,
    .ss_size = 0,
    .ss_flags = TARGET_SS_DISABLE,
};

static struct emulated_sigaction sigact_table[TARGET_NSIG];
static struct sigqueue sigqueue_table[MAX_SIGQUEUE_SIZE]; /* siginfo queue */
static struct sigqueue *first_free; /* first free siginfo queue entry */
static int signal_pending; /* non zero if a signal may be pending */

static void host_signal_handler(int host_signum, siginfo_t *info,
                                void *puc);

static uint8_t host_to_target_signal_table[65] = {
    [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 */
};
static uint8_t target_to_host_signal_table[65];

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);
}

static inline int host_to_target_signal(int sig)
{
    return host_to_target_signal_table[sig];
}

static inline int target_to_host_signal(int sig)
{
    return target_to_host_signal_table[sig];
}

static void host_to_target_sigset_internal(target_sigset_t *d,
                                           const sigset_t *s)
{
    int i;
    unsigned long sigmask;
    uint32_t target_sigmask;

    sigmask = ((unsigned long *)s)[0];
    target_sigmask = 0;
    for(i = 0; i < 32; i++) {
        if (sigmask & (1 << i))
            target_sigmask |= 1 << (host_to_target_signal(i + 1) - 1);
    }
#if TARGET_LONG_BITS == 32 && HOST_LONG_BITS == 32
    d->sig[0] = target_sigmask;
    for(i = 1;i < TARGET_NSIG_WORDS; i++) {
        d->sig[i] = ((unsigned long *)s)[i];
    }
#elif TARGET_LONG_BITS == 32 && HOST_LONG_BITS == 64 && TARGET_NSIG_WORDS == 2
    d->sig[0] = target_sigmask;
    d->sig[1] = sigmask >> 32;
#else
#warning host_to_target_sigset
#endif
}

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] = tswapl(d1.sig[i]);
}

void target_to_host_sigset_internal(sigset_t *d, const target_sigset_t *s)
{
    int i;
    unsigned long sigmask;
    target_ulong target_sigmask;

    target_sigmask = s->sig[0];
    sigmask = 0;
    for(i = 0; i < 32; i++) {
        if (target_sigmask & (1 << i))
            sigmask |= 1 << (target_to_host_signal(i + 1) - 1);
    }
#if TARGET_LONG_BITS == 32 && HOST_LONG_BITS == 32
    ((unsigned long *)d)[0] = sigmask;
    for(i = 1;i < TARGET_NSIG_WORDS; i++) {
        ((unsigned long *)d)[i] = s->sig[i];
    }
#elif TARGET_LONG_BITS == 32 && HOST_LONG_BITS == 64 && TARGET_NSIG_WORDS == 2
    ((unsigned long *)d)[0] = sigmask | ((unsigned long)(s->sig[1]) << 32);
#else
#warning target_to_host_sigset
#endif /* TARGET_LONG_BITS */
}

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] = tswapl(s->sig[i]);
    target_to_host_sigset_internal(d, &s1);
}

void host_to_target_old_sigset(target_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 target_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);
}

/* siginfo conversion */

static inline void host_to_target_siginfo_noswap(target_siginfo_t *tinfo,
                                                 const siginfo_t *info)
{
    int sig;
    sig = host_to_target_signal(info->si_signo);
    tinfo->si_signo = sig;
    tinfo->si_errno = 0;
    tinfo->si_code = 0;
    if (sig == SIGILL || sig == SIGFPE || sig == SIGSEGV ||
        sig == SIGBUS || sig == SIGTRAP) {
        /* should never come here, but who knows. The information for
           the target is irrelevant */
        tinfo->_sifields._sigfault._addr = 0;
    } else if (sig == SIGIO) {
	tinfo->_sifields._sigpoll._fd = info->si_fd;
    } 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 =
            (target_ulong)info->si_value.sival_ptr;
    }
}

static void tswap_siginfo(target_siginfo_t *tinfo,
                          const target_siginfo_t *info)
{
    int sig;
    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 == SIGILL || sig == SIGFPE || sig == SIGSEGV ||
        sig == SIGBUS || sig == SIGTRAP) {
        tinfo->_sifields._sigfault._addr =
            tswapl(info->_sifields._sigfault._addr);
    } else if (sig == SIGIO) {
	tinfo->_sifields._sigpoll._fd = tswap32(info->_sifields._sigpoll._fd);
    } 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 =
            tswapl(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 *)tswapl(tinfo->_sifields._rt._sigval.sival_ptr);
}

void signal_init(void)
{
    struct sigaction act;
    int i, j;

    /* generate signal conversion tables */
    for(i = 1; i <= 64; i++) {
        if (host_to_target_signal_table[i] == 0)
            host_to_target_signal_table[i] = i;
    }
    for(i = 1; i <= 64; i++) {
        j = host_to_target_signal_table[i];
        target_to_host_signal_table[j] = i;
    }

    /* set all host signal handlers. ALL signals are blocked during
       the handlers to serialize them. */
    sigfillset(&act.sa_mask);
    act.sa_flags = SA_SIGINFO;
    act.sa_sigaction = host_signal_handler;
    for(i = 1; i < NSIG; i++) {
        sigaction(i, &act, NULL);
    }

    memset(sigact_table, 0, sizeof(sigact_table));

    first_free = &sigqueue_table[0];
    for(i = 0; i < MAX_SIGQUEUE_SIZE - 1; i++)
        sigqueue_table[i].next = &sigqueue_table[i + 1];
    sigqueue_table[MAX_SIGQUEUE_SIZE - 1].next = NULL;
}

/* signal queue handling */

static inline struct sigqueue *alloc_sigqueue(void)
{
    struct sigqueue *q = first_free;
    if (!q)
        return NULL;
    first_free = q->next;
    return q;
}

static inline void free_sigqueue(struct sigqueue *q)
{
    q->next = first_free;
    first_free = q;
}

/* abort execution with signal */
void __attribute((noreturn)) force_sig(int sig)
{
    int host_sig;
    host_sig = target_to_host_signal(sig);
    fprintf(stderr, "qemu: uncaught target signal %d (%s) - exiting\n",
            sig, strsignal(host_sig));
#if 1
    _exit(-host_sig);
#else
    {
        struct sigaction act;
        sigemptyset(&act.sa_mask);
        act.sa_flags = SA_SIGINFO;
        act.sa_sigaction = SIG_DFL;
        sigaction(SIGABRT, &act, NULL);
        abort();
    }
#endif
}

/* queue a signal so that it will be send to the virtual CPU as soon
   as possible */
int queue_signal(int sig, target_siginfo_t *info)
{
    struct emulated_sigaction *k;
    struct sigqueue *q, **pq;
    target_ulong handler;

#if defined(DEBUG_SIGNAL)
    fprintf(stderr, "queue_signal: sig=%d\n",
            sig);
#endif
    k = &sigact_table[sig - 1];
    handler = k->sa._sa_handler;
    if (handler == TARGET_SIG_DFL) {
        /* default handler : ignore some signal. The other are fatal */
        if (sig != TARGET_SIGCHLD &&
            sig != TARGET_SIGURG &&
            sig != TARGET_SIGWINCH) {
            force_sig(sig);
        } else {
            return 0; /* indicate ignored */
        }
    } else if (handler == TARGET_SIG_IGN) {
        /* ignore signal */
        return 0;
    } else if (handler == TARGET_SIG_ERR) {
        force_sig(sig);
    } else {
        pq = &k->first;
        if (sig < TARGET_SIGRTMIN) {
            /* if non real time signal, we queue exactly one signal */
            if (!k->pending)
                q = &k->info;
            else
                return 0;
        } else {
            if (!k->pending) {
                /* first signal */
                q = &k->info;
            } else {
                q = alloc_sigqueue();
                if (!q)
                    return -EAGAIN;
                while (*pq != NULL)
                    pq = &(*pq)->next;
            }
        }
        *pq = q;
        q->info = *info;
        q->next = NULL;
        k->pending = 1;
        /* signal that a new signal is pending */
        signal_pending = 1;
        return 1; /* indicates that the signal was queued */
    }
}

static void host_signal_handler(int host_signum, siginfo_t *info,
                                void *puc)
{
    int sig;
    target_siginfo_t tinfo;

    /* the CPU emulator uses some host signals to detect exceptions,
       we we forward to it some signals */
    if (host_signum == SIGSEGV || host_signum == SIGBUS
#if defined(TARGET_I386) && defined(USE_CODE_COPY)
        || host_signum == SIGFPE
#endif
        ) {
        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;
#if defined(DEBUG_SIGNAL)
    fprintf(stderr, "qemu: got signal %d\n", sig);
#endif
    host_to_target_siginfo_noswap(&tinfo, info);
    if (queue_signal(sig, &tinfo) == 1) {
        /* interrupt the virtual CPU as soon as possible */
        cpu_interrupt(global_env, CPU_INTERRUPT_EXIT);
    }
}

int do_sigaltstack(const struct target_sigaltstack *uss,
                   struct target_sigaltstack *uoss,
                   target_ulong sp)
{
    int ret;
    struct target_sigaltstack oss;

    /* XXX: test errors */
    if(uoss)
    {
        __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)
    {
	struct target_sigaltstack ss;

	ret = -EFAULT;
	if (!access_ok(VERIFY_READ, uss, sizeof(*uss))
	    || __get_user(ss.ss_sp, &uss->ss_sp)
	    || __get_user(ss.ss_size, &uss->ss_size)
	    || __get_user(ss.ss_flags, &uss->ss_flags))
            goto out;

	ret = -EPERM;
	if (on_sig_stack(sp))
            goto out;

	ret = -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 = -ENOMEM;
            if (ss.ss_size < MINSIGSTKSZ)
                goto out;
	}

        target_sigaltstack_used.ss_sp = ss.ss_sp;
        target_sigaltstack_used.ss_size = ss.ss_size;
    }

    if (uoss) {
        ret = -EFAULT;
        if (!access_ok(VERIFY_WRITE, uoss, sizeof(oss)))
            goto out;
        memcpy(uoss, &oss, sizeof(oss));
    }

    ret = 0;
out:
    return ret;
}

int do_sigaction(int sig, const struct target_sigaction *act,
                 struct target_sigaction *oact)
{
    struct emulated_sigaction *k;
    struct sigaction act1;
    int host_sig;

    if (sig < 1 || sig > TARGET_NSIG || sig == SIGKILL || sig == SIGSTOP)
        return -EINVAL;
    k = &sigact_table[sig - 1];
#if defined(DEBUG_SIGNAL)
    fprintf(stderr, "sigaction sig=%d act=0x%08x, oact=0x%08x\n",
            sig, (int)act, (int)oact);
#endif
    if (oact) {
        oact->_sa_handler = tswapl(k->sa._sa_handler);
        oact->sa_flags = tswapl(k->sa.sa_flags);
#if !defined(TARGET_MIPS)
        oact->sa_restorer = tswapl(k->sa.sa_restorer);
#endif
        oact->sa_mask = k->sa.sa_mask;
    }
    if (act) {
        k->sa._sa_handler = tswapl(act->_sa_handler);
        k->sa.sa_flags = tswapl(act->sa_flags);
#if !defined(TARGET_MIPS)
        k->sa.sa_restorer = tswapl(act->sa_restorer);
#endif
        k->sa.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.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._sa_handler == TARGET_SIG_IGN) {
                act1.sa_sigaction = (void *)SIG_IGN;
            } else if (k->sa._sa_handler == TARGET_SIG_DFL) {
                act1.sa_sigaction = (void *)SIG_DFL;
            } else {
                act1.sa_sigaction = host_signal_handler;
            }
            sigaction(host_sig, &act1, NULL);
        }
    }
    return 0;
}

#ifndef offsetof
#define offsetof(type, field) ((size_t) &((type *)0)->field)
#endif

static inline int copy_siginfo_to_user(target_siginfo_t *tinfo,
                                       const target_siginfo_t *info)
{
    tswap_siginfo(tinfo, info);
    return 0;
}

#ifdef TARGET_I386

/* 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 {
	target_ulong element[4];
};

struct target_fpstate {
	/* Regular FPU environment */
	target_ulong 	cw;
	target_ulong	sw;
	target_ulong	tag;
	target_ulong	ipoff;
	target_ulong	cssel;
	target_ulong	dataoff;
	target_ulong	datasel;
	struct target_fpreg	_st[8];
	uint16_t	status;
	uint16_t	magic;		/* 0xffff = regular FPU data only */

	/* FXSR FPU environment */
	target_ulong	_fxsr_env[6];	/* FXSR FPU env is ignored */
	target_ulong	mxcsr;
	target_ulong	reserved;
	struct target_fpxreg	_fxsr_st[8];	/* FXSR FPU reg data is ignored */
	struct target_xmmreg	_xmm[8];
	target_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;
	target_ulong edi;
	target_ulong esi;
	target_ulong ebp;
	target_ulong esp;
	target_ulong ebx;
	target_ulong edx;
	target_ulong ecx;
	target_ulong eax;
	target_ulong trapno;
	target_ulong err;
	target_ulong eip;
	uint16_t cs, __csh;
	target_ulong eflags;
	target_ulong esp_at_signal;
	uint16_t ss, __ssh;
        target_ulong fpstate; /* pointer */
	target_ulong oldmask;
	target_ulong cr2;
};

struct target_ucontext {
        target_ulong	  tuc_flags;
	target_ulong      tuc_link;
	target_stack_t	  tuc_stack;
	struct target_sigcontext tuc_mcontext;
	target_sigset_t	  tuc_sigmask;	/* mask last for extensibility */
};

struct sigframe
{
    target_ulong pretcode;
    int sig;
    struct target_sigcontext sc;
    struct target_fpstate fpstate;
    target_ulong extramask[TARGET_NSIG_WORDS-1];
    char retcode[8];
};

struct rt_sigframe
{
    target_ulong pretcode;
    int sig;
    target_ulong pinfo;
    target_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 int
setup_sigcontext(struct target_sigcontext *sc, struct target_fpstate *fpstate,
		 CPUX86State *env, unsigned long mask)
{
	int err = 0;

	err |= __put_user(env->segs[R_GS].selector, (unsigned int *)&sc->gs);
	err |= __put_user(env->segs[R_FS].selector, (unsigned int *)&sc->fs);
	err |= __put_user(env->segs[R_ES].selector, (unsigned int *)&sc->es);
	err |= __put_user(env->segs[R_DS].selector, (unsigned int *)&sc->ds);
	err |= __put_user(env->regs[R_EDI], &sc->edi);
	err |= __put_user(env->regs[R_ESI], &sc->esi);
	err |= __put_user(env->regs[R_EBP], &sc->ebp);
	err |= __put_user(env->regs[R_ESP], &sc->esp);
	err |= __put_user(env->regs[R_EBX], &sc->ebx);
	err |= __put_user(env->regs[R_EDX], &sc->edx);
	err |= __put_user(env->regs[R_ECX], &sc->ecx);
	err |= __put_user(env->regs[R_EAX], &sc->eax);
	err |= __put_user(env->exception_index, &sc->trapno);
	err |= __put_user(env->error_code, &sc->err);
	err |= __put_user(env->eip, &sc->eip);
	err |= __put_user(env->segs[R_CS].selector, (unsigned int *)&sc->cs);
	err |= __put_user(env->eflags, &sc->eflags);
	err |= __put_user(env->regs[R_ESP], &sc->esp_at_signal);
	err |= __put_user(env->segs[R_SS].selector, (unsigned int *)&sc->ss);

        cpu_x86_fsave(env, (void *)fpstate, 1);
        fpstate->status = fpstate->sw;
        err |= __put_user(0xffff, &fpstate->magic);
        err |= __put_user(fpstate, &sc->fpstate);

	/* non-iBCS2 extensions.. */
	err |= __put_user(mask, &sc->oldmask);
	err |= __put_user(env->cr[2], &sc->cr2);
	return err;
}

/*
 * Determine which stack to use..
 */

static inline void *
get_sigframe(struct emulated_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.sa_flags & TARGET_SA_ONSTACK) {
            if (sas_ss_flags(esp) == 0)
                esp = target_sigaltstack_used.ss_sp + target_sigaltstack_used.ss_size;
        }

	/* This is the legacy signal stack switching. */
	else
        if ((env->segs[R_SS].selector & 0xffff) != __USER_DS &&
            !(ka->sa.sa_flags & TARGET_SA_RESTORER) &&
            ka->sa.sa_restorer) {
            esp = (unsigned long) ka->sa.sa_restorer;
	}
        return g2h((esp - frame_size) & -8ul);
}

static void setup_frame(int sig, struct emulated_sigaction *ka,
			target_sigset_t *set, CPUX86State *env)
{
	struct sigframe *frame;
	int i, err = 0;

	frame = get_sigframe(ka, env, sizeof(*frame));

	if (!access_ok(VERIFY_WRITE, frame, sizeof(*frame)))
		goto give_sigsegv;
	err |= __put_user((/*current->exec_domain
		           && current->exec_domain->signal_invmap
		           && sig < 32
		           ? current->exec_domain->signal_invmap[sig]
		           : */ sig),
		          &frame->sig);
	if (err)
		goto give_sigsegv;

	setup_sigcontext(&frame->sc, &frame->fpstate, env, set->sig[0]);
	if (err)
		goto give_sigsegv;

        for(i = 1; i < TARGET_NSIG_WORDS; i++) {
            if (__put_user(set->sig[i], &frame->extramask[i - 1]))
                goto give_sigsegv;
        }

	/* Set up to return from userspace.  If provided, use a stub
	   already in userspace.  */
	if (ka->sa.sa_flags & TARGET_SA_RESTORER) {
		err |= __put_user(ka->sa.sa_restorer, &frame->pretcode);
	} else {
		err |= __put_user(frame->retcode, &frame->pretcode);
		/* This is popl %eax ; movl $,%eax ; int $0x80 */
		err |= __put_user(0xb858, (short *)(frame->retcode+0));
#if defined(TARGET_X86_64)
#warning "Fix this !"
#else
		err |= __put_user(TARGET_NR_sigreturn, (int *)(frame->retcode+2));
#endif
		err |= __put_user(0x80cd, (short *)(frame->retcode+6));
	}

	if (err)
		goto give_sigsegv;

	/* Set up registers for signal handler */
	env->regs[R_ESP] = h2g(frame);
	env->eip = (unsigned long) ka->sa._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;

	return;

give_sigsegv:
	if (sig == TARGET_SIGSEGV)
		ka->sa._sa_handler = TARGET_SIG_DFL;
	force_sig(TARGET_SIGSEGV /* , current */);
}

static void setup_rt_frame(int sig, struct emulated_sigaction *ka,
                           target_siginfo_t *info,
			   target_sigset_t *set, CPUX86State *env)
{
	struct rt_sigframe *frame;
	int i, err = 0;

	frame = get_sigframe(ka, env, sizeof(*frame));

	if (!access_ok(VERIFY_WRITE, frame, sizeof(*frame)))
		goto give_sigsegv;

	err |= __put_user((/*current->exec_domain
		    	   && current->exec_domain->signal_invmap
		    	   && sig < 32
		    	   ? current->exec_domain->signal_invmap[sig]
			   : */sig),
			  &frame->sig);
	err |= __put_user((target_ulong)&frame->info, &frame->pinfo);
	err |= __put_user((target_ulong)&frame->uc, &frame->puc);
	err |= copy_siginfo_to_user(&frame->info, info);
	if (err)
		goto give_sigsegv;

	/* Create the ucontext.  */
	err |= __put_user(0, &frame->uc.tuc_flags);
	err |= __put_user(0, &frame->uc.tuc_link);
	err |= __put_user(target_sigaltstack_used.ss_sp,
			  &frame->uc.tuc_stack.ss_sp);
	err |= __put_user(sas_ss_flags(get_sp_from_cpustate(env)),
			  &frame->uc.tuc_stack.ss_flags);
	err |= __put_user(target_sigaltstack_used.ss_size,
			  &frame->uc.tuc_stack.ss_size);
	err |= setup_sigcontext(&frame->uc.tuc_mcontext, &frame->fpstate,
			        env, set->sig[0]);
        for(i = 0; i < TARGET_NSIG_WORDS; i++) {
            if (__put_user(set->sig[i], &frame->uc.tuc_sigmask.sig[i]))
                goto give_sigsegv;
        }

	/* Set up to return from userspace.  If provided, use a stub
	   already in userspace.  */
	if (ka->sa.sa_flags & TARGET_SA_RESTORER) {
		err |= __put_user(ka->sa.sa_restorer, &frame->pretcode);
	} else {
		err |= __put_user(frame->retcode, &frame->pretcode);
		/* This is movl $,%eax ; int $0x80 */
		err |= __put_user(0xb8, (char *)(frame->retcode+0));
		err |= __put_user(TARGET_NR_rt_sigreturn, (int *)(frame->retcode+1));
		err |= __put_user(0x80cd, (short *)(frame->retcode+5));
	}

	if (err)
		goto give_sigsegv;

	/* Set up registers for signal handler */
	env->regs[R_ESP] = (unsigned long) frame;
	env->eip = (unsigned long) ka->sa._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;

	return;

give_sigsegv:
	if (sig == TARGET_SIGSEGV)
		ka->sa._sa_handler = TARGET_SIG_DFL;
	force_sig(TARGET_SIGSEGV /* , current */);
}

static int
restore_sigcontext(CPUX86State *env, struct target_sigcontext *sc, int *peax)
{
	unsigned int err = 0;

        cpu_x86_load_seg(env, R_GS, lduw(&sc->gs));
        cpu_x86_load_seg(env, R_FS, lduw(&sc->fs));
        cpu_x86_load_seg(env, R_ES, lduw(&sc->es));
        cpu_x86_load_seg(env, R_DS, lduw(&sc->ds));

        env->regs[R_EDI] = ldl(&sc->edi);
        env->regs[R_ESI] = ldl(&sc->esi);
        env->regs[R_EBP] = ldl(&sc->ebp);
        env->regs[R_ESP] = ldl(&sc->esp);
        env->regs[R_EBX] = ldl(&sc->ebx);
        env->regs[R_EDX] = ldl(&sc->edx);
        env->regs[R_ECX] = ldl(&sc->ecx);
        env->eip = ldl(&sc->eip);

        cpu_x86_load_seg(env, R_CS, lduw(&sc->cs) | 3);
        cpu_x86_load_seg(env, R_SS, lduw(&sc->ss) | 3);

	{
		unsigned int tmpflags;
                tmpflags = ldl(&sc->eflags);
		env->eflags = (env->eflags & ~0x40DD5) | (tmpflags & 0x40DD5);
                //		regs->orig_eax = -1;		/* disable syscall checks */
	}

	{
		struct _fpstate * buf;
                buf = (void *)ldl(&sc->fpstate);
		if (buf) {
#if 0
			if (verify_area(VERIFY_READ, buf, sizeof(*buf)))
				goto badframe;
#endif
                        cpu_x86_frstor(env, (void *)buf, 1);
		}
	}

        *peax = ldl(&sc->eax);
	return err;
#if 0
badframe:
	return 1;
#endif
}

long do_sigreturn(CPUX86State *env)
{
    struct sigframe *frame = (struct sigframe *)g2h(env->regs[R_ESP] - 8);
    target_sigset_t target_set;
    sigset_t set;
    int eax, i;

#if defined(DEBUG_SIGNAL)
    fprintf(stderr, "do_sigreturn\n");
#endif
    /* set blocked signals */
    if (__get_user(target_set.sig[0], &frame->sc.oldmask))
        goto badframe;
    for(i = 1; i < TARGET_NSIG_WORDS; i++) {
        if (__get_user(target_set.sig[i], &frame->extramask[i - 1]))
            goto badframe;
    }

    target_to_host_sigset_internal(&set, &target_set);
    sigprocmask(SIG_SETMASK, &set, NULL);

    /* restore registers */
    if (restore_sigcontext(env, &frame->sc, &eax))
        goto badframe;
    return eax;

badframe:
    force_sig(TARGET_SIGSEGV);
    return 0;
}

long do_rt_sigreturn(CPUX86State *env)
{
	struct rt_sigframe *frame = (struct rt_sigframe *)g2h(env->regs[R_ESP] - 4);
        sigset_t set;
	int eax;

#if 0
	if (verify_area(VERIFY_READ, frame, sizeof(*frame)))
		goto badframe;
#endif
        target_to_host_sigset(&set, &frame->uc.tuc_sigmask);
        sigprocmask(SIG_SETMASK, &set, NULL);

	if (restore_sigcontext(env, &frame->uc.tuc_mcontext, &eax))
		goto badframe;

	if (do_sigaltstack(&frame->uc.tuc_stack, NULL, get_sp_from_cpustate(env)) == -EFAULT)
		goto badframe;

	return eax;

badframe:
	force_sig(TARGET_SIGSEGV);
	return 0;
}

#elif defined(TARGET_ARM)

struct target_sigcontext {
	target_ulong trap_no;
	target_ulong error_code;
	target_ulong oldmask;
	target_ulong arm_r0;
	target_ulong arm_r1;
	target_ulong arm_r2;
	target_ulong arm_r3;
	target_ulong arm_r4;
	target_ulong arm_r5;
	target_ulong arm_r6;
	target_ulong arm_r7;
	target_ulong arm_r8;
	target_ulong arm_r9;
	target_ulong arm_r10;
	target_ulong arm_fp;
	target_ulong arm_ip;
	target_ulong arm_sp;
	target_ulong arm_lr;
	target_ulong arm_pc;
	target_ulong arm_cpsr;
	target_ulong fault_address;
};

struct target_ucontext {
    target_ulong tuc_flags;
    target_ulong tuc_link;
    target_stack_t tuc_stack;
    struct target_sigcontext tuc_mcontext;
    target_sigset_t  tuc_sigmask;	/* mask last for extensibility */
};

struct sigframe
{
    struct target_sigcontext sc;
    target_ulong extramask[TARGET_NSIG_WORDS-1];
    target_ulong retcode;
};

struct rt_sigframe
{
    struct target_siginfo *pinfo;
    void *puc;
    struct target_siginfo info;
    struct target_ucontext uc;
    target_ulong retcode;
};

#define TARGET_CONFIG_CPU_32 1

/*
 * For ARM syscalls, we encode the syscall number into the instruction.
 */
#define SWI_SYS_SIGRETURN	(0xef000000|(TARGET_NR_sigreturn + ARM_SYSCALL_BASE))
#define SWI_SYS_RT_SIGRETURN	(0xef000000|(TARGET_NR_rt_sigreturn + ARM_SYSCALL_BASE))

/*
 * For Thumb syscalls, we pass the syscall number via r7.  We therefore
 * need two 16-bit instructions.
 */
#define SWI_THUMB_SIGRETURN	(0xdf00 << 16 | 0x2700 | (TARGET_NR_sigreturn))
#define SWI_THUMB_RT_SIGRETURN	(0xdf00 << 16 | 0x2700 | (TARGET_NR_rt_sigreturn))

static const target_ulong retcodes[4] = {
	SWI_SYS_SIGRETURN,	SWI_THUMB_SIGRETURN,
	SWI_SYS_RT_SIGRETURN,	SWI_THUMB_RT_SIGRETURN
};


#define __put_user_error(x,p,e) __put_user(x, p)
#define __get_user_error(x,p,e) __get_user(x, p)

static inline int valid_user_regs(CPUState *regs)
{
    return 1;
}

static int
setup_sigcontext(struct target_sigcontext *sc, /*struct _fpstate *fpstate,*/
		 CPUState *env, unsigned long mask)
{
	int err = 0;

	__put_user_error(env->regs[0], &sc->arm_r0, err);
	__put_user_error(env->regs[1], &sc->arm_r1, err);
	__put_user_error(env->regs[2], &sc->arm_r2, err);
	__put_user_error(env->regs[3], &sc->arm_r3, err);
	__put_user_error(env->regs[4], &sc->arm_r4, err);
	__put_user_error(env->regs[5], &sc->arm_r5, err);
	__put_user_error(env->regs[6], &sc->arm_r6, err);
	__put_user_error(env->regs[7], &sc->arm_r7, err);
	__put_user_error(env->regs[8], &sc->arm_r8, err);
	__put_user_error(env->regs[9], &sc->arm_r9, err);
	__put_user_error(env->regs[10], &sc->arm_r10, err);
	__put_user_error(env->regs[11], &sc->arm_fp, err);
	__put_user_error(env->regs[12], &sc->arm_ip, err);
	__put_user_error(env->regs[13], &sc->arm_sp, err);
	__put_user_error(env->regs[14], &sc->arm_lr, err);
	__put_user_error(env->regs[15], &sc->arm_pc, err);
#ifdef TARGET_CONFIG_CPU_32
	__put_user_error(cpsr_read(env), &sc->arm_cpsr, err);
#endif

	__put_user_error(/* current->thread.trap_no */ 0, &sc->trap_no, err);
	__put_user_error(/* current->thread.error_code */ 0, &sc->error_code, err);
	__put_user_error(/* current->thread.address */ 0, &sc->fault_address, err);
	__put_user_error(mask, &sc->oldmask, err);

	return err;
}

static inline void *
get_sigframe(struct emulated_sigaction *ka, CPUState *regs, int framesize)
{
	unsigned long sp = regs->regs[13];

	/*
	 * This is the X/Open sanctioned signal stack switching.
	 */
	if ((ka->sa.sa_flags & TARGET_SA_ONSTACK) && !sas_ss_flags(sp))
            sp = target_sigaltstack_used.ss_sp + target_sigaltstack_used.ss_size;
	/*
	 * ATPCS B01 mandates 8-byte alignment
	 */
	return g2h((sp - framesize) & ~7);
}

static int
setup_return(CPUState *env, struct emulated_sigaction *ka,
	     target_ulong *rc, void *frame, int usig)
{
	target_ulong handler = (target_ulong)ka->sa._sa_handler;
	target_ulong retcode;
	int thumb = 0;
#if defined(TARGET_CONFIG_CPU_32)
#if 0
	target_ulong cpsr = env->cpsr;

	/*
	 * Maybe we need to deliver a 32-bit signal to a 26-bit task.
	 */
	if (ka->sa.sa_flags & SA_THIRTYTWO)
		cpsr = (cpsr & ~MODE_MASK) | USR_MODE;

#ifdef CONFIG_ARM_THUMB
	if (elf_hwcap & HWCAP_THUMB) {
		/*
		 * The LSB of the handler determines if we're going to
		 * be using THUMB or ARM mode for this signal handler.
		 */
		thumb = handler & 1;

		if (thumb)
			cpsr |= T_BIT;
		else
			cpsr &= ~T_BIT;
	}
#endif /* CONFIG_ARM_THUMB */
#endif /* 0 */
#endif /* TARGET_CONFIG_CPU_32 */

	if (ka->sa.sa_flags & TARGET_SA_RESTORER) {
		retcode = (target_ulong)ka->sa.sa_restorer;
	} else {
		unsigned int idx = thumb;

		if (ka->sa.sa_flags & TARGET_SA_SIGINFO)
			idx += 2;

		if (__put_user(retcodes[idx], rc))
			return 1;
#if 0
		flush_icache_range((target_ulong)rc,
				   (target_ulong)(rc + 1));
#endif
		retcode = ((target_ulong)rc) + thumb;
	}

	env->regs[0] = usig;
	env->regs[13] = h2g(frame);
	env->regs[14] = retcode;
	env->regs[15] = handler & (thumb ? ~1 : ~3);

#if 0
#ifdef TARGET_CONFIG_CPU_32
	env->cpsr = cpsr;
#endif
#endif

	return 0;
}

static void setup_frame(int usig, struct emulated_sigaction *ka,
			target_sigset_t *set, CPUState *regs)
{
	struct sigframe *frame = get_sigframe(ka, regs, sizeof(*frame));
	int i, err = 0;

	err |= setup_sigcontext(&frame->sc, /*&frame->fpstate,*/ regs, set->sig[0]);

        for(i = 1; i < TARGET_NSIG_WORDS; i++) {
            if (__put_user(set->sig[i], &frame->extramask[i - 1]))
                return;
	}

	if (err == 0)
            err = setup_return(regs, ka, &frame->retcode, frame, usig);
        //	return err;
}

static void setup_rt_frame(int usig, struct emulated_sigaction *ka,
                           target_siginfo_t *info,
			   target_sigset_t *set, CPUState *env)
{
	struct rt_sigframe *frame = get_sigframe(ka, env, sizeof(*frame));
	struct target_sigaltstack stack;
	int i, err = 0;

	if (!access_ok(VERIFY_WRITE, frame, sizeof (*frame)))
            return /* 1 */;

	__put_user_error(&frame->info, (target_ulong *)&frame->pinfo, err);
	__put_user_error(&frame->uc, (target_ulong *)&frame->puc, err);
	err |= copy_siginfo_to_user(&frame->info, info);

	/* Clear all the bits of the ucontext we don't use.  */
	memset(&frame->uc, 0, offsetof(struct target_ucontext, tuc_mcontext));

        memset(&stack, 0, sizeof(stack));
        __put_user(target_sigaltstack_used.ss_sp, &stack.ss_sp);
        __put_user(target_sigaltstack_used.ss_size, &stack.ss_size);
        __put_user(sas_ss_flags(get_sp_from_cpustate(env)), &stack.ss_flags);
        if (!access_ok(VERIFY_WRITE, &frame->uc.tuc_stack, sizeof(stack)))
            err = 1;
        else
            memcpy(&frame->uc.tuc_stack, &stack, sizeof(stack));

	err |= setup_sigcontext(&frame->uc.tuc_mcontext, /*&frame->fpstate,*/
				env, set->sig[0]);
        for(i = 0; i < TARGET_NSIG_WORDS; i++) {
            if (__put_user(set->sig[i], &frame->uc.tuc_sigmask.sig[i]))
                return;
        }

	if (err == 0)
		err = setup_return(env, ka, &frame->retcode, frame, usig);

	if (err == 0) {
		/*
		 * For realtime signals we must also set the second and third
		 * arguments for the signal handler.
		 *   -- Peter Maydell <pmaydell@chiark.greenend.org.uk> 2000-12-06
		 */
            env->regs[1] = (target_ulong)frame->pinfo;
            env->regs[2] = (target_ulong)frame->puc;
	}

        //	return err;
}

static int
restore_sigcontext(CPUState *env, struct target_sigcontext *sc)
{
	int err = 0;
        uint32_t cpsr;

	__get_user_error(env->regs[0], &sc->arm_r0, err);
	__get_user_error(env->regs[1], &sc->arm_r1, err);
	__get_user_error(env->regs[2], &sc->arm_r2, err);
	__get_user_error(env->regs[3], &sc->arm_r3, err);
	__get_user_error(env->regs[4], &sc->arm_r4, err);
	__get_user_error(env->regs[5], &sc->arm_r5, err);
	__get_user_error(env->regs[6], &sc->arm_r6, err);
	__get_user_error(env->regs[7], &sc->arm_r7, err);
	__get_user_error(env->regs[8], &sc->arm_r8, err);
	__get_user_error(env->regs[9], &sc->arm_r9, err);
	__get_user_error(env->regs[10], &sc->arm_r10, err);
	__get_user_error(env->regs[11], &sc->arm_fp, err);
	__get_user_error(env->regs[12], &sc->arm_ip, err);
	__get_user_error(env->regs[13], &sc->arm_sp, err);
	__get_user_error(env->regs[14], &sc->arm_lr, err);
	__get_user_error(env->regs[15], &sc->arm_pc, err);
#ifdef TARGET_CONFIG_CPU_32
	__get_user_error(cpsr, &sc->arm_cpsr, err);
        cpsr_write(env, cpsr, 0xffffffff);
#endif

	err |= !valid_user_regs(env);

	return err;
}

long do_sigreturn(CPUState *env)
{
	struct sigframe *frame;
	target_sigset_t set;
        sigset_t host_set;
        int i;

	/*
	 * Since we stacked the signal on a 64-bit boundary,
	 * then 'sp' should be word aligned here.  If it's
	 * not, then the user is trying to mess with us.
	 */
	if (env->regs[13] & 7)
		goto badframe;

	frame = (struct sigframe *)g2h(env->regs[13]);

#if 0
	if (verify_area(VERIFY_READ, frame, sizeof (*frame)))
		goto badframe;
#endif
	if (__get_user(set.sig[0], &frame->sc.oldmask))
            goto badframe;
        for(i = 1; i < TARGET_NSIG_WORDS; i++) {
            if (__get_user(set.sig[i], &frame->extramask[i - 1]))
                goto badframe;
        }

        target_to_host_sigset_internal(&host_set, &set);
        sigprocmask(SIG_SETMASK, &host_set, NULL);

	if (restore_sigcontext(env, &frame->sc))
		goto badframe;

#if 0
	/* Send SIGTRAP if we're single-stepping */
	if (ptrace_cancel_bpt(current))
		send_sig(SIGTRAP, current, 1);
#endif
	return env->regs[0];

badframe:
        force_sig(SIGSEGV /* , current */);
	return 0;
}

long do_rt_sigreturn(CPUState *env)
{
	struct rt_sigframe *frame;
        sigset_t host_set;

	/*
	 * Since we stacked the signal on a 64-bit boundary,
	 * then 'sp' should be word aligned here.  If it's
	 * not, then the user is trying to mess with us.
	 */
	if (env->regs[13] & 7)
		goto badframe;

	frame = (struct rt_sigframe *)env->regs[13];

#if 0
	if (verify_area(VERIFY_READ, frame, sizeof (*frame)))
		goto badframe;
#endif
        target_to_host_sigset(&host_set, &frame->uc.tuc_sigmask);
        sigprocmask(SIG_SETMASK, &host_set, NULL);

	if (restore_sigcontext(env, &frame->uc.tuc_mcontext))
		goto badframe;

	if (do_sigaltstack(&frame->uc.tuc_stack, NULL, get_sp_from_cpustate(env)) == -EFAULT)
		goto badframe;

#if 0
	/* Send SIGTRAP if we're single-stepping */
	if (ptrace_cancel_bpt(current))
		send_sig(SIGTRAP, current, 1);
#endif
	return env->regs[0];

badframe:
        force_sig(SIGSEGV /* , current */);
	return 0;
}

#elif defined(TARGET_SPARC)

#define __SUNOS_MAXWIN   31

/* This is what SunOS does, so shall I. */
struct target_sigcontext {
        target_ulong sigc_onstack;      /* state to restore */

        target_ulong sigc_mask;         /* sigmask to restore */
        target_ulong sigc_sp;           /* stack pointer */
        target_ulong sigc_pc;           /* program counter */
        target_ulong sigc_npc;          /* next program counter */
        target_ulong sigc_psr;          /* for condition codes etc */
        target_ulong sigc_g1;           /* User uses these two registers */
        target_ulong sigc_o0;           /* within the trampoline code. */

        /* Now comes information regarding the users window set
         * at the time of the signal.
         */
        target_ulong sigc_oswins;       /* outstanding windows */

        /* stack ptrs for each regwin buf */
        char *sigc_spbuf[__SUNOS_MAXWIN];

        /* Windows to restore after signal */
        struct {
                target_ulong locals[8];
                target_ulong ins[8];
        } sigc_wbuf[__SUNOS_MAXWIN];
};
/* A Sparc stack frame */
struct sparc_stackf {
        target_ulong locals[8];
        target_ulong ins[6];
        struct sparc_stackf *fp;
        target_ulong callers_pc;
        char *structptr;
        target_ulong xargs[6];
        target_ulong xxargs[1];
};

typedef struct {
        struct {
                target_ulong psr;
                target_ulong pc;
                target_ulong npc;
                target_ulong y;
                target_ulong u_regs[16]; /* globals and ins */
        }               si_regs;
        int             si_mask;
} __siginfo_t;

typedef struct {
        unsigned   long si_float_regs [32];
        unsigned   long si_fsr;
        unsigned   long si_fpqdepth;
        struct {
                unsigned long *insn_addr;
                unsigned long insn;
        } si_fpqueue [16];
} qemu_siginfo_fpu_t;


struct target_signal_frame {
	struct sparc_stackf	ss;
	__siginfo_t		info;
	qemu_siginfo_fpu_t 	*fpu_save;
	target_ulong		insns[2] __attribute__ ((aligned (8)));
	target_ulong		extramask[TARGET_NSIG_WORDS - 1];
	target_ulong		extra_size; /* Should be 0 */
	qemu_siginfo_fpu_t	fpu_state;
};
struct target_rt_signal_frame {
	struct sparc_stackf	ss;
	siginfo_t		info;
	target_ulong		regs[20];
	sigset_t		mask;
	qemu_siginfo_fpu_t 	*fpu_save;
	unsigned int		insns[2];
	stack_t			stack;
	unsigned int		extra_size; /* Should be 0 */
	qemu_siginfo_fpu_t	fpu_state;
};

#define UREG_O0        16
#define UREG_O6        22
#define UREG_I0        0
#define UREG_I1        1
#define UREG_I2        2
#define UREG_I6        6
#define UREG_I7        7
#define UREG_L0	       8
#define UREG_FP        UREG_I6
#define UREG_SP        UREG_O6

static inline void *get_sigframe(struct emulated_sigaction *sa, CPUState *env, unsigned long framesize)
{
	unsigned long sp;

	sp = env->regwptr[UREG_FP];

	/* This is the X/Open sanctioned signal stack switching.  */
	if (sa->sa.sa_flags & TARGET_SA_ONSTACK) {
            if (!on_sig_stack(sp)
                && !((target_sigaltstack_used.ss_sp + target_sigaltstack_used.ss_size) & 7))
                sp = target_sigaltstack_used.ss_sp + target_sigaltstack_used.ss_size;
	}
	return g2h(sp - framesize);
}

static int
setup___siginfo(__siginfo_t *si, CPUState *env, target_ulong mask)
{
	int err = 0, i;

	err |= __put_user(env->psr, &si->si_regs.psr);
	err |= __put_user(env->pc, &si->si_regs.pc);
	err |= __put_user(env->npc, &si->si_regs.npc);
	err |= __put_user(env->y, &si->si_regs.y);
	for (i=0; i < 8; i++) {
		err |= __put_user(env->gregs[i], &si->si_regs.u_regs[i]);
	}
	for (i=0; i < 8; i++) {
		err |= __put_user(env->regwptr[UREG_I0 + i], &si->si_regs.u_regs[i+8]);
	}
	err |= __put_user(mask, &si->si_mask);
	return err;
}

#if 0
static int
setup_sigcontext(struct target_sigcontext *sc, /*struct _fpstate *fpstate,*/
		 CPUState *env, unsigned long mask)
{
	int err = 0;

	err |= __put_user(mask, &sc->sigc_mask);
	err |= __put_user(env->regwptr[UREG_SP], &sc->sigc_sp);
	err |= __put_user(env->pc, &sc->sigc_pc);
	err |= __put_user(env->npc, &sc->sigc_npc);
	err |= __put_user(env->psr, &sc->sigc_psr);
	err |= __put_user(env->gregs[1], &sc->sigc_g1);
	err |= __put_user(env->regwptr[UREG_O0], &sc->sigc_o0);

	return err;
}
#endif
#define NF_ALIGNEDSZ  (((sizeof(struct target_signal_frame) + 7) & (~7)))

static void setup_frame(int sig, struct emulated_sigaction *ka,
			target_sigset_t *set, CPUState *env)
{
	struct target_signal_frame *sf;
	int sigframe_size, err, i;

	/* 1. Make sure everything is clean */
	//synchronize_user_stack();

        sigframe_size = NF_ALIGNEDSZ;

	sf = (struct target_signal_frame *)
		get_sigframe(ka, env, sigframe_size);

	//fprintf(stderr, "sf: %x pc %x fp %x sp %x\n", sf, env->pc, env->regwptr[UREG_FP], env->regwptr[UREG_SP]);
#if 0
	if (invalid_frame_pointer(sf, sigframe_size))
		goto sigill_and_return;
#endif
	/* 2. Save the current process state */
	err = setup___siginfo(&sf->info, env, set->sig[0]);
	err |= __put_user(0, &sf->extra_size);

	//err |= save_fpu_state(regs, &sf->fpu_state);
	//err |= __put_user(&sf->fpu_state, &sf->fpu_save);

	err |= __put_user(set->sig[0], &sf->info.si_mask);
	for (i = 0; i < TARGET_NSIG_WORDS - 1; i++) {
		err |= __put_user(set->sig[i + 1], &sf->extramask[i]);
	}

	for (i = 0; i < 8; i++) {
	  	err |= __put_user(env->regwptr[i + UREG_L0], &sf->ss.locals[i]);
	}
	for (i = 0; i < 8; i++) {
	  	err |= __put_user(env->regwptr[i + UREG_I0], &sf->ss.ins[i]);
	}
	if (err)
		goto sigsegv;

	/* 3. signal handler back-trampoline and parameters */
	env->regwptr[UREG_FP] = h2g(sf);
	env->regwptr[UREG_I0] = sig;
	env->regwptr[UREG_I1] = h2g(&sf->info);
	env->regwptr[UREG_I2] = h2g(&sf->info);

	/* 4. signal handler */
	env->pc = (unsigned long) ka->sa._sa_handler;
	env->npc = (env->pc + 4);
	/* 5. return to kernel instructions */
	if (ka->sa.sa_restorer)
		env->regwptr[UREG_I7] = (unsigned long)ka->sa.sa_restorer;
	else {
		env->regwptr[UREG_I7] = h2g(&(sf->insns[0]) - 2);

		/* mov __NR_sigreturn, %g1 */
		err |= __put_user(0x821020d8, &sf->insns[0]);

		/* t 0x10 */
		err |= __put_user(0x91d02010, &sf->insns[1]);
		if (err)
			goto sigsegv;

		/* Flush instruction space. */
		//flush_sig_insns(current->mm, (unsigned long) &(sf->insns[0]));
                //		tb_flush(env);
	}
	return;

        //sigill_and_return:
	force_sig(TARGET_SIGILL);
sigsegv:
	//fprintf(stderr, "force_sig\n");
	force_sig(TARGET_SIGSEGV);
}
static inline int
restore_fpu_state(CPUState *env, qemu_siginfo_fpu_t *fpu)
{
        int err;
#if 0
#ifdef CONFIG_SMP
        if (current->flags & PF_USEDFPU)
                regs->psr &= ~PSR_EF;
#else
        if (current == last_task_used_math) {
                last_task_used_math = 0;
                regs->psr &= ~PSR_EF;
        }
#endif
        current->used_math = 1;
        current->flags &= ~PF_USEDFPU;
#endif
#if 0
        if (verify_area (VERIFY_READ, fpu, sizeof(*fpu)))
                return -EFAULT;
#endif

#if 0
        /* XXX: incorrect */
        err = __copy_from_user(&env->fpr[0], &fpu->si_float_regs[0],
	                             (sizeof(unsigned long) * 32));
#endif
        err |= __get_user(env->fsr, &fpu->si_fsr);
#if 0
        err |= __get_user(current->thread.fpqdepth, &fpu->si_fpqdepth);
        if (current->thread.fpqdepth != 0)
                err |= __copy_from_user(&current->thread.fpqueue[0],
                                        &fpu->si_fpqueue[0],
                                        ((sizeof(unsigned long) +
                                        (sizeof(unsigned long *)))*16));
#endif
        return err;
}


static void setup_rt_frame(int sig, struct emulated_sigaction *ka,
                           target_siginfo_t *info,
			   target_sigset_t *set, CPUState *env)
{
    fprintf(stderr, "setup_rt_frame: not implemented\n");
}

long do_sigreturn(CPUState *env)
{
        struct target_signal_frame *sf;
        uint32_t up_psr, pc, npc;
        target_sigset_t set;
        sigset_t host_set;
        target_ulong fpu_save;
        int err, i;

        sf = (struct target_signal_frame *)g2h(env->regwptr[UREG_FP]);
#if 0
	fprintf(stderr, "sigreturn\n");
	fprintf(stderr, "sf: %x pc %x fp %x sp %x\n", sf, env->pc, env->regwptr[UREG_FP], env->regwptr[UREG_SP]);
#endif
	//cpu_dump_state(env, stderr, fprintf, 0);

        /* 1. Make sure we are not getting garbage from the user */
#if 0
        if (verify_area (VERIFY_READ, sf, sizeof (*sf)))
                goto segv_and_exit;
#endif

        if (((uint) sf) & 3)
                goto segv_and_exit;

        err = __get_user(pc,  &sf->info.si_regs.pc);
        err |= __get_user(npc, &sf->info.si_regs.npc);

        if ((pc | npc) & 3)
                goto segv_and_exit;

        /* 2. Restore the state */
        err |= __get_user(up_psr, &sf->info.si_regs.psr);

        /* User can only change condition codes and FPU enabling in %psr. */
        env->psr = (up_psr & (PSR_ICC /* | PSR_EF */))
                  | (env->psr & ~(PSR_ICC /* | PSR_EF */));

	env->pc = pc;
	env->npc = npc;
        err |= __get_user(env->y, &sf->info.si_regs.y);
	for (i=0; i < 8; i++) {
		err |= __get_user(env->gregs[i], &sf->info.si_regs.u_regs[i]);
	}
	for (i=0; i < 8; i++) {
		err |= __get_user(env->regwptr[i + UREG_I0], &sf->info.si_regs.u_regs[i+8]);
	}

        err |= __get_user(fpu_save, (target_ulong *)&sf->fpu_save);

        //if (fpu_save)
        //        err |= restore_fpu_state(env, fpu_save);

        /* This is pretty much atomic, no amount locking would prevent
         * the races which exist anyways.
         */
        err |= __get_user(set.sig[0], &sf->info.si_mask);
        for(i = 1; i < TARGET_NSIG_WORDS; i++) {
            err |= (__get_user(set.sig[i], &sf->extramask[i - 1]));
        }

        target_to_host_sigset_internal(&host_set, &set);
        sigprocmask(SIG_SETMASK, &host_set, NULL);

        if (err)
                goto segv_and_exit;

        return env->regwptr[0];

segv_and_exit:
	force_sig(TARGET_SIGSEGV);
}

long do_rt_sigreturn(CPUState *env)
{
    fprintf(stderr, "do_rt_sigreturn: not implemented\n");
    return -ENOSYS;
}

#elif defined(TARGET_MIPS)

struct target_sigcontext {
    uint32_t   sc_regmask;     /* Unused */
    uint32_t   sc_status;
    uint64_t   sc_pc;
    uint64_t   sc_regs[32];
    uint64_t   sc_fpregs[32];
    uint32_t   sc_ownedfp;     /* Unused */
    uint32_t   sc_fpc_csr;
    uint32_t   sc_fpc_eir;     /* Unused */
    uint32_t   sc_used_math;
    uint32_t   sc_dsp;         /* dsp status, was sc_ssflags */
    uint64_t   sc_mdhi;
    uint64_t   sc_mdlo;
    target_ulong   sc_hi1;         /* Was sc_cause */
    target_ulong   sc_lo1;         /* Was sc_badvaddr */
    target_ulong   sc_hi2;         /* Was sc_sigset[4] */
    target_ulong   sc_lo2;
    target_ulong   sc_hi3;
    target_ulong   sc_lo3;
};

struct sigframe {
    uint32_t sf_ass[4];			/* argument save space for o32 */
    uint32_t sf_code[2];			/* signal trampoline */
    struct target_sigcontext sf_sc;
    target_sigset_t sf_mask;
};

/* Install trampoline to jump back from signal handler */
static inline int install_sigtramp(unsigned int *tramp,   unsigned int syscall)
{
    int err;

    /*
    * Set up the return code ...
    *
    *         li      v0, __NR__foo_sigreturn
    *         syscall
    */

    err = __put_user(0x24020000 + syscall, tramp + 0);
    err |= __put_user(0x0000000c          , tramp + 1);
    /* flush_cache_sigtramp((unsigned long) tramp); */
    return err;
}

static inline int
setup_sigcontext(CPUState *regs, struct target_sigcontext *sc)
{
    int err = 0;

    err |= __put_user(regs->PC[regs->current_tc], &sc->sc_pc);

#define save_gp_reg(i) do {   							\
        err |= __put_user(regs->gpr[i][regs->current_tc], &sc->sc_regs[i]);	\
    } while(0)
    __put_user(0, &sc->sc_regs[0]); save_gp_reg(1); save_gp_reg(2);
    save_gp_reg(3); save_gp_reg(4); save_gp_reg(5); save_gp_reg(6);
    save_gp_reg(7); save_gp_reg(8); save_gp_reg(9); save_gp_reg(10);
    save_gp_reg(11); save_gp_reg(12); save_gp_reg(13); save_gp_reg(14);
    save_gp_reg(15); save_gp_reg(16); save_gp_reg(17); save_gp_reg(18);
    save_gp_reg(19); save_gp_reg(20); save_gp_reg(21); save_gp_reg(22);
    save_gp_reg(23); save_gp_reg(24); save_gp_reg(25); save_gp_reg(26);
    save_gp_reg(27); save_gp_reg(28); save_gp_reg(29); save_gp_reg(30);
    save_gp_reg(31);
#undef save_gp_reg

    err |= __put_user(regs->HI[0][regs->current_tc], &sc->sc_mdhi);
    err |= __put_user(regs->LO[0][regs->current_tc], &sc->sc_mdlo);

    /* Not used yet, but might be useful if we ever have DSP suppport */
#if 0
    if (cpu_has_dsp) {
	err |= __put_user(mfhi1(), &sc->sc_hi1);
	err |= __put_user(mflo1(), &sc->sc_lo1);
	err |= __put_user(mfhi2(), &sc->sc_hi2);
	err |= __put_user(mflo2(), &sc->sc_lo2);
	err |= __put_user(mfhi3(), &sc->sc_hi3);
	err |= __put_user(mflo3(), &sc->sc_lo3);
	err |= __put_user(rddsp(DSP_MASK), &sc->sc_dsp);
    }
    /* same with 64 bit */
#ifdef CONFIG_64BIT
    err |= __put_user(regs->hi, &sc->sc_hi[0]);
    err |= __put_user(regs->lo, &sc->sc_lo[0]);
    if (cpu_has_dsp) {
	err |= __put_user(mfhi1(), &sc->sc_hi[1]);
	err |= __put_user(mflo1(), &sc->sc_lo[1]);
	err |= __put_user(mfhi2(), &sc->sc_hi[2]);
	err |= __put_user(mflo2(), &sc->sc_lo[2]);
	err |= __put_user(mfhi3(), &sc->sc_hi[3]);
	err |= __put_user(mflo3(), &sc->sc_lo[3]);
	err |= __put_user(rddsp(DSP_MASK), &sc->sc_dsp);
    }
#endif
#endif

#if 0
    err |= __put_user(!!used_math(), &sc->sc_used_math);

    if (!used_math())
	goto out;

    /*
    * Save FPU state to signal context.  Signal handler will "inherit"
    * current FPU state.
    */
    preempt_disable();

    if (!is_fpu_owner()) {
	own_fpu();
	restore_fp(current);
    }
    err |= save_fp_context(sc);

    preempt_enable();
    out:
#endif
    return err;
}

static inline int
restore_sigcontext(CPUState *regs, struct target_sigcontext *sc)
{
    int err = 0;

    err |= __get_user(regs->CP0_EPC, &sc->sc_pc);

    err |= __get_user(regs->HI[0][regs->current_tc], &sc->sc_mdhi);
    err |= __get_user(regs->LO[0][regs->current_tc], &sc->sc_mdlo);

#define restore_gp_reg(i) do {   							\
        err |= __get_user(regs->gpr[i][regs->current_tc], &sc->sc_regs[i]);		\
    } while(0)
    restore_gp_reg( 1); restore_gp_reg( 2); restore_gp_reg( 3);
    restore_gp_reg( 4); restore_gp_reg( 5); restore_gp_reg( 6);
    restore_gp_reg( 7); restore_gp_reg( 8); restore_gp_reg( 9);
    restore_gp_reg(10); restore_gp_reg(11); restore_gp_reg(12);
    restore_gp_reg(13); restore_gp_reg(14); restore_gp_reg(15);
    restore_gp_reg(16); restore_gp_reg(17); restore_gp_reg(18);
    restore_gp_reg(19); restore_gp_reg(20); restore_gp_reg(21);
    restore_gp_reg(22); restore_gp_reg(23); restore_gp_reg(24);
    restore_gp_reg(25); restore_gp_reg(26); restore_gp_reg(27);
    restore_gp_reg(28); restore_gp_reg(29); restore_gp_reg(30);
    restore_gp_reg(31);
#undef restore_gp_reg

#if 0
    if (cpu_has_dsp) {
	err |= __get_user(treg, &sc->sc_hi1); mthi1(treg);
	err |= __get_user(treg, &sc->sc_lo1); mtlo1(treg);
	err |= __get_user(treg, &sc->sc_hi2); mthi2(treg);
	err |= __get_user(treg, &sc->sc_lo2); mtlo2(treg);
	err |= __get_user(treg, &sc->sc_hi3); mthi3(treg);
	err |= __get_user(treg, &sc->sc_lo3); mtlo3(treg);
	err |= __get_user(treg, &sc->sc_dsp); wrdsp(treg, DSP_MASK);
    }
#ifdef CONFIG_64BIT
    err |= __get_user(regs->hi, &sc->sc_hi[0]);
    err |= __get_user(regs->lo, &sc->sc_lo[0]);
    if (cpu_has_dsp) {
	err |= __get_user(treg, &sc->sc_hi[1]); mthi1(treg);
	err |= __get_user(treg, &sc->sc_lo[1]); mthi1(treg);
	err |= __get_user(treg, &sc->sc_hi[2]); mthi2(treg);
	err |= __get_user(treg, &sc->sc_lo[2]); mthi2(treg);
	err |= __get_user(treg, &sc->sc_hi[3]); mthi3(treg);
	err |= __get_user(treg, &sc->sc_lo[3]); mthi3(treg);
	err |= __get_user(treg, &sc->sc_dsp); wrdsp(treg, DSP_MASK);
    }
#endif

    err |= __get_user(used_math, &sc->sc_used_math);
    conditional_used_math(used_math);

    preempt_disable();

    if (used_math()) {
	/* restore fpu context if we have used it before */
	own_fpu();
	err |= restore_fp_context(sc);
    } else {
	/* signal handler may have used FPU.  Give it up. */
	lose_fpu();
    }

    preempt_enable();
#endif
    return err;
}
/*
 * Determine which stack to use..
 */
static inline void *
get_sigframe(struct emulated_sigaction *ka, CPUState *regs, size_t frame_size)
{
    unsigned long sp;

    /* Default to using normal stack */
    sp = regs->gpr[29][regs->current_tc];

    /*
     * FPU emulator may have it's own trampoline active just
     * above the user stack, 16-bytes before the next lowest
     * 16 byte boundary.  Try to avoid trashing it.
     */
    sp -= 32;

    /* This is the X/Open sanctioned signal stack switching.  */
    if ((ka->sa.sa_flags & TARGET_SA_ONSTACK) && (sas_ss_flags (sp) == 0)) {
        sp = target_sigaltstack_used.ss_sp + target_sigaltstack_used.ss_size;
    }

    return g2h((sp - frame_size) & ~7);
}

static void setup_frame(int sig, struct emulated_sigaction * ka,
   		target_sigset_t *set, CPUState *regs)
{
    struct sigframe *frame;
    int i;

    frame = get_sigframe(ka, regs, sizeof(*frame));
    if (!access_ok(VERIFY_WRITE, frame, sizeof (*frame)))
	goto give_sigsegv;

    install_sigtramp(frame->sf_code, TARGET_NR_sigreturn);

    if(setup_sigcontext(regs, &frame->sf_sc))
	goto give_sigsegv;

    for(i = 0; i < TARGET_NSIG_WORDS; i++) {
	if(__put_user(set->sig[i], &frame->sf_mask.sig[i]))
	    goto give_sigsegv;
    }

    /*
    * Arguments to signal handler:
    *
    *   a0 = signal number
    *   a1 = 0 (should be cause)
    *   a2 = pointer to struct sigcontext
    *
    * $25 and PC point to the signal handler, $29 points to the
    * struct sigframe.
    */
    regs->gpr[ 4][regs->current_tc] = sig;
    regs->gpr[ 5][regs->current_tc] = 0;
    regs->gpr[ 6][regs->current_tc] = h2g(&frame->sf_sc);
    regs->gpr[29][regs->current_tc] = h2g(frame);
    regs->gpr[31][regs->current_tc] = h2g(frame->sf_code);
    /* The original kernel code sets CP0_EPC to the handler
    * since it returns to userland using eret
    * we cannot do this here, and we must set PC directly */
    regs->PC[regs->current_tc] = regs->gpr[25][regs->current_tc] = ka->sa._sa_handler;
    return;

give_sigsegv:
    force_sig(TARGET_SIGSEGV/*, current*/);
    return;
}

long do_sigreturn(CPUState *regs)
{
    struct sigframe *frame;
    sigset_t blocked;
    target_sigset_t target_set;
    int i;

#if defined(DEBUG_SIGNAL)
    fprintf(stderr, "do_sigreturn\n");
#endif
    frame = (struct sigframe *) regs->gpr[29][regs->current_tc];
    if (!access_ok(VERIFY_READ, frame, sizeof(*frame)))
   	goto badframe;

    for(i = 0; i < TARGET_NSIG_WORDS; i++) {
   	if(__get_user(target_set.sig[i], &frame->sf_mask.sig[i]))
	    goto badframe;
    }

    target_to_host_sigset_internal(&blocked, &target_set);
    sigprocmask(SIG_SETMASK, &blocked, NULL);

    if (restore_sigcontext(regs, &frame->sf_sc))
   	goto badframe;

#if 0
    /*
     * Don't let your children do this ...
     */
    __asm__ __volatile__(
   	"move\t$29, %0\n\t"
   	"j\tsyscall_exit"
   	:/* no outputs */
   	:"r" (&regs));
    /* Unreached */
#endif

    regs->PC[regs->current_tc] = regs->CP0_EPC;
    /* I am not sure this is right, but it seems to work
    * maybe a problem with nested signals ? */
    regs->CP0_EPC = 0;
    return 0;

badframe:
    force_sig(TARGET_SIGSEGV/*, current*/);
    return 0;
}

static void setup_rt_frame(int sig, struct emulated_sigaction *ka,
                           target_siginfo_t *info,
			   target_sigset_t *set, CPUState *env)
{
    fprintf(stderr, "setup_rt_frame: not implemented\n");
}

long do_rt_sigreturn(CPUState *env)
{
    fprintf(stderr, "do_rt_sigreturn: not implemented\n");
    return -ENOSYS;
}

#else

static void setup_frame(int sig, struct emulated_sigaction *ka,
			target_sigset_t *set, CPUState *env)
{
    fprintf(stderr, "setup_frame: not implemented\n");
}

static void setup_rt_frame(int sig, struct emulated_sigaction *ka,
                           target_siginfo_t *info,
			   target_sigset_t *set, CPUState *env)
{
    fprintf(stderr, "setup_rt_frame: not implemented\n");
}

long do_sigreturn(CPUState *env)
{
    fprintf(stderr, "do_sigreturn: not implemented\n");
    return -ENOSYS;
}

long do_rt_sigreturn(CPUState *env)
{
    fprintf(stderr, "do_rt_sigreturn: not implemented\n");
    return -ENOSYS;
}

#endif

void process_pending_signals(void *cpu_env)
{
    int sig;
    target_ulong handler;
    sigset_t set, old_set;
    target_sigset_t target_old_set;
    struct emulated_sigaction *k;
    struct sigqueue *q;

    if (!signal_pending)
        return;

    k = sigact_table;
    for(sig = 1; sig <= TARGET_NSIG; sig++) {
        if (k->pending)
            goto handle_signal;
        k++;
    }
    /* if no signal is pending, just return */
    signal_pending = 0;
    return;

 handle_signal:
#ifdef DEBUG_SIGNAL
    fprintf(stderr, "qemu: process signal %d\n", sig);
#endif
    /* dequeue signal */
    q = k->first;
    k->first = q->next;
    if (!k->first)
        k->pending = 0;

    sig = gdb_handlesig (cpu_env, sig);
    if (!sig) {
        fprintf (stderr, "Lost signal\n");
        abort();
    }

    handler = k->sa._sa_handler;
    if (handler == TARGET_SIG_DFL) {
        /* default handler : ignore some signal. The other are fatal */
        if (sig != TARGET_SIGCHLD &&
            sig != TARGET_SIGURG &&
            sig != TARGET_SIGWINCH) {
            force_sig(sig);
        }
    } else if (handler == TARGET_SIG_IGN) {
        /* ignore sig */
    } else if (handler == TARGET_SIG_ERR) {
        force_sig(sig);
    } else {
        /* compute the blocked signals during the handler execution */
        target_to_host_sigset(&set, &k->sa.sa_mask);
        /* SA_NODEFER indicates that the current signal should not be
           blocked during the handler */
        if (!(k->sa.sa_flags & TARGET_SA_NODEFER))
            sigaddset(&set, target_to_host_signal(sig));

        /* block signals in the handler using Linux */
        sigprocmask(SIG_BLOCK, &set, &old_set);
        /* save the previous blocked signal state to restore it at the
           end of the signal execution (see do_sigreturn) */
        host_to_target_sigset_internal(&target_old_set, &old_set);

        /* if the CPU is in VM86 mode, we restore the 32 bit values */
#if defined(TARGET_I386) && !defined(TARGET_X86_64)
        {
            CPUX86State *env = cpu_env;
            if (env->eflags & VM_MASK)
                save_v86_state(env);
        }
#endif
        /* prepare the stack frame of the virtual CPU */
        if (k->sa.sa_flags & TARGET_SA_SIGINFO)
            setup_rt_frame(sig, k, &q->info, &target_old_set, cpu_env);
        else
            setup_frame(sig, k, &target_old_set, cpu_env);
	if (k->sa.sa_flags & TARGET_SA_RESETHAND)
            k->sa._sa_handler = TARGET_SIG_DFL;
    }
    if (q != &k->info)
        free_sigqueue(q);
}