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[gcc.git] / gcc / ada / init.c
1 /****************************************************************************
2 * *
3 * GNAT COMPILER COMPONENTS *
4 * *
5 * I N I T *
6 * *
7 * C Implementation File *
8 * *
9 * Copyright (C) 1992-2012, Free Software Foundation, Inc. *
10 * *
11 * GNAT is free software; you can redistribute it and/or modify it under *
12 * terms of the GNU General Public License as published by the Free Soft- *
13 * ware Foundation; either version 3, or (at your option) any later ver- *
14 * sion. GNAT is distributed in the hope that it will be useful, but WITH- *
15 * OUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY *
16 * or FITNESS FOR A PARTICULAR PURPOSE. *
17 * *
18 * As a special exception under Section 7 of GPL version 3, you are granted *
19 * additional permissions described in the GCC Runtime Library Exception, *
20 * version 3.1, as published by the Free Software Foundation. *
21 * *
22 * You should have received a copy of the GNU General Public License and *
23 * a copy of the GCC Runtime Library Exception along with this program; *
24 * see the files COPYING3 and COPYING.RUNTIME respectively. If not, see *
25 * <http://www.gnu.org/licenses/>. *
26 * *
27 * GNAT was originally developed by the GNAT team at New York University. *
28 * Extensive contributions were provided by Ada Core Technologies Inc. *
29 * *
30 ****************************************************************************/
31
32 /* This unit contains initialization circuits that are system dependent.
33 A major part of the functionality involves stack overflow checking.
34 The GCC backend generates probe instructions to test for stack overflow.
35 For details on the exact approach used to generate these probes, see the
36 "Using and Porting GCC" manual, in particular the "Stack Checking" section
37 and the subsection "Specifying How Stack Checking is Done". The handlers
38 installed by this file are used to catch the resulting signals that come
39 from these probes failing (i.e. touching protected pages). */
40
41 /* This file should be kept synchronized with 2sinit.ads, 2sinit.adb,
42 s-init-ae653-cert.adb and s-init-xi-sparc.adb. All these files implement
43 the required functionality for different targets. */
44
45 /* The following include is here to meet the published VxWorks requirement
46 that the __vxworks header appear before any other include. */
47 #ifdef __vxworks
48 #include "vxWorks.h"
49 #endif
50
51 #ifdef __ANDROID__
52 #undef linux
53 #endif
54
55 #ifdef IN_RTS
56 #include "tconfig.h"
57 #include "tsystem.h"
58 #include <sys/stat.h>
59
60 /* We don't have libiberty, so use malloc. */
61 #define xmalloc(S) malloc (S)
62 #else
63 #include "config.h"
64 #include "system.h"
65 #endif
66
67 #include "adaint.h"
68 #include "raise.h"
69
70 #ifdef __cplusplus
71 extern "C" {
72 #endif
73
74 extern void __gnat_raise_program_error (const char *, int);
75
76 /* Addresses of exception data blocks for predefined exceptions. Tasking_Error
77 is not used in this unit, and the abort signal is only used on IRIX.
78 ??? Revisit this part since IRIX is no longer supported. */
79 extern struct Exception_Data constraint_error;
80 extern struct Exception_Data numeric_error;
81 extern struct Exception_Data program_error;
82 extern struct Exception_Data storage_error;
83
84 /* For the Cert run time we use the regular raise exception routine because
85 Raise_From_Signal_Handler is not available. */
86 #ifdef CERT
87 #define Raise_From_Signal_Handler \
88 __gnat_raise_exception
89 extern void Raise_From_Signal_Handler (struct Exception_Data *, const char *);
90 #else
91 #define Raise_From_Signal_Handler \
92 ada__exceptions__raise_from_signal_handler
93 extern void Raise_From_Signal_Handler (struct Exception_Data *, const char *);
94 #endif
95
96 /* Global values computed by the binder. */
97 int __gl_main_priority = -1;
98 int __gl_main_cpu = -1;
99 int __gl_time_slice_val = -1;
100 char __gl_wc_encoding = 'n';
101 char __gl_locking_policy = ' ';
102 char __gl_queuing_policy = ' ';
103 char __gl_task_dispatching_policy = ' ';
104 char *__gl_priority_specific_dispatching = 0;
105 int __gl_num_specific_dispatching = 0;
106 char *__gl_interrupt_states = 0;
107 int __gl_num_interrupt_states = 0;
108 int __gl_unreserve_all_interrupts = 0;
109 int __gl_exception_tracebacks = 0;
110 int __gl_detect_blocking = 0;
111 int __gl_default_stack_size = -1;
112 int __gl_leap_seconds_support = 0;
113 int __gl_canonical_streams = 0;
114
115 /* This value is not used anymore, but kept for bootstrapping purpose. */
116 int __gl_zero_cost_exceptions = 0;
117
118 /* Indication of whether synchronous signal handler has already been
119 installed by a previous call to adainit. */
120 int __gnat_handler_installed = 0;
121
122 #ifndef IN_RTS
123 int __gnat_inside_elab_final_code = 0;
124 /* ??? This variable is obsolete since 2001-08-29 but is kept to allow
125 bootstrap from old GNAT versions (< 3.15). */
126 #endif
127
128 /* HAVE_GNAT_INIT_FLOAT must be set on every targets where a __gnat_init_float
129 is defined. If this is not set then a void implementation will be defined
130 at the end of this unit. */
131 #undef HAVE_GNAT_INIT_FLOAT
132
133 /******************************/
134 /* __gnat_get_interrupt_state */
135 /******************************/
136
137 char __gnat_get_interrupt_state (int);
138
139 /* This routine is called from the runtime as needed to determine the state
140 of an interrupt, as set by an Interrupt_State pragma appearing anywhere
141 in the current partition. The input argument is the interrupt number,
142 and the result is one of the following:
143
144 'n' this interrupt not set by any Interrupt_State pragma
145 'u' Interrupt_State pragma set state to User
146 'r' Interrupt_State pragma set state to Runtime
147 's' Interrupt_State pragma set state to System */
148
149 char
150 __gnat_get_interrupt_state (int intrup)
151 {
152 if (intrup >= __gl_num_interrupt_states)
153 return 'n';
154 else
155 return __gl_interrupt_states [intrup];
156 }
157
158 /***********************************/
159 /* __gnat_get_specific_dispatching */
160 /***********************************/
161
162 char __gnat_get_specific_dispatching (int);
163
164 /* This routine is called from the runtime as needed to determine the
165 priority specific dispatching policy, as set by a
166 Priority_Specific_Dispatching pragma appearing anywhere in the current
167 partition. The input argument is the priority number, and the result
168 is the upper case first character of the policy name, e.g. 'F' for
169 FIFO_Within_Priorities. A space ' ' is returned if no
170 Priority_Specific_Dispatching pragma is used in the partition. */
171
172 char
173 __gnat_get_specific_dispatching (int priority)
174 {
175 if (__gl_num_specific_dispatching == 0)
176 return ' ';
177 else if (priority >= __gl_num_specific_dispatching)
178 return 'F';
179 else
180 return __gl_priority_specific_dispatching [priority];
181 }
182
183 #ifndef IN_RTS
184
185 /**********************/
186 /* __gnat_set_globals */
187 /**********************/
188
189 /* This routine is kept for bootstrapping purposes, since the binder generated
190 file now sets the __gl_* variables directly. */
191
192 void
193 __gnat_set_globals (void)
194 {
195 }
196
197 #endif
198
199 /***************/
200 /* AIX Section */
201 /***************/
202
203 #if defined (_AIX)
204
205 #include <signal.h>
206 #include <sys/time.h>
207
208 /* Some versions of AIX don't define SA_NODEFER. */
209
210 #ifndef SA_NODEFER
211 #define SA_NODEFER 0
212 #endif /* SA_NODEFER */
213
214 /* Versions of AIX before 4.3 don't have nanosleep but provide
215 nsleep instead. */
216
217 #ifndef _AIXVERSION_430
218
219 extern int nanosleep (struct timestruc_t *, struct timestruc_t *);
220
221 int
222 nanosleep (struct timestruc_t *Rqtp, struct timestruc_t *Rmtp)
223 {
224 return nsleep (Rqtp, Rmtp);
225 }
226
227 #endif /* _AIXVERSION_430 */
228
229 /* Version of AIX before 5.3 don't have pthread_condattr_setclock:
230 * supply it as a weak symbol here so that if linking on a 5.3 or newer
231 * machine, we get the real one.
232 */
233
234 #ifndef _AIXVERSION_530
235 #pragma weak pthread_condattr_setclock
236 int
237 pthread_condattr_setclock (pthread_condattr_t *attr, clockid_t cl) {
238 return 0;
239 }
240 #endif
241
242 static void
243 __gnat_error_handler (int sig,
244 siginfo_t *si ATTRIBUTE_UNUSED,
245 void *ucontext ATTRIBUTE_UNUSED)
246 {
247 struct Exception_Data *exception;
248 const char *msg;
249
250 switch (sig)
251 {
252 case SIGSEGV:
253 /* FIXME: we need to detect the case of a *real* SIGSEGV. */
254 exception = &storage_error;
255 msg = "stack overflow or erroneous memory access";
256 break;
257
258 case SIGBUS:
259 exception = &constraint_error;
260 msg = "SIGBUS";
261 break;
262
263 case SIGFPE:
264 exception = &constraint_error;
265 msg = "SIGFPE";
266 break;
267
268 default:
269 exception = &program_error;
270 msg = "unhandled signal";
271 }
272
273 Raise_From_Signal_Handler (exception, msg);
274 }
275
276 void
277 __gnat_install_handler (void)
278 {
279 struct sigaction act;
280
281 /* Set up signal handler to map synchronous signals to appropriate
282 exceptions. Make sure that the handler isn't interrupted by another
283 signal that might cause a scheduling event! */
284
285 act.sa_flags = SA_NODEFER | SA_RESTART | SA_SIGINFO;
286 act.sa_sigaction = __gnat_error_handler;
287 sigemptyset (&act.sa_mask);
288
289 /* Do not install handlers if interrupt state is "System". */
290 if (__gnat_get_interrupt_state (SIGABRT) != 's')
291 sigaction (SIGABRT, &act, NULL);
292 if (__gnat_get_interrupt_state (SIGFPE) != 's')
293 sigaction (SIGFPE, &act, NULL);
294 if (__gnat_get_interrupt_state (SIGILL) != 's')
295 sigaction (SIGILL, &act, NULL);
296 if (__gnat_get_interrupt_state (SIGSEGV) != 's')
297 sigaction (SIGSEGV, &act, NULL);
298 if (__gnat_get_interrupt_state (SIGBUS) != 's')
299 sigaction (SIGBUS, &act, NULL);
300
301 __gnat_handler_installed = 1;
302 }
303
304 /*****************/
305 /* HP-UX section */
306 /*****************/
307
308 #elif defined (__hpux__)
309
310 #include <signal.h>
311 #include <sys/ucontext.h>
312
313 #if defined (IN_RTS) && defined (__ia64__)
314
315 #include <sys/uc_access.h>
316
317 #define HAVE_GNAT_ADJUST_CONTEXT_FOR_RAISE
318
319 void
320 __gnat_adjust_context_for_raise (int signo ATTRIBUTE_UNUSED, void *ucontext)
321 {
322 ucontext_t *uc = (ucontext_t *) ucontext;
323 uint64_t ip;
324
325 /* Adjust on itanium, as GetIPInfo is not supported. */
326 __uc_get_ip (uc, &ip);
327 __uc_set_ip (uc, ip + 1);
328 }
329 #endif /* IN_RTS && __ia64__ */
330
331 /* Tasking and Non-tasking signal handler. Map SIGnal to Ada exception
332 propagation after the required low level adjustments. */
333
334 static void
335 __gnat_error_handler (int sig,
336 siginfo_t *si ATTRIBUTE_UNUSED,
337 void *ucontext ATTRIBUTE_UNUSED)
338 {
339 struct Exception_Data *exception;
340 const char *msg;
341
342 __gnat_adjust_context_for_raise (sig, ucontext);
343
344 switch (sig)
345 {
346 case SIGSEGV:
347 /* FIXME: we need to detect the case of a *real* SIGSEGV. */
348 exception = &storage_error;
349 msg = "stack overflow or erroneous memory access";
350 break;
351
352 case SIGBUS:
353 exception = &constraint_error;
354 msg = "SIGBUS";
355 break;
356
357 case SIGFPE:
358 exception = &constraint_error;
359 msg = "SIGFPE";
360 break;
361
362 default:
363 exception = &program_error;
364 msg = "unhandled signal";
365 }
366
367 Raise_From_Signal_Handler (exception, msg);
368 }
369
370 /* This must be in keeping with System.OS_Interface.Alternate_Stack_Size. */
371 #if defined (__hppa__)
372 char __gnat_alternate_stack[16 * 1024]; /* 2 * SIGSTKSZ */
373 #else
374 char __gnat_alternate_stack[128 * 1024]; /* MINSIGSTKSZ */
375 #endif
376
377 void
378 __gnat_install_handler (void)
379 {
380 struct sigaction act;
381
382 /* Set up signal handler to map synchronous signals to appropriate
383 exceptions. Make sure that the handler isn't interrupted by another
384 signal that might cause a scheduling event! Also setup an alternate
385 stack region for the handler execution so that stack overflows can be
386 handled properly, avoiding a SEGV generation from stack usage by the
387 handler itself. */
388
389 stack_t stack;
390 stack.ss_sp = __gnat_alternate_stack;
391 stack.ss_size = sizeof (__gnat_alternate_stack);
392 stack.ss_flags = 0;
393 sigaltstack (&stack, NULL);
394
395 act.sa_sigaction = __gnat_error_handler;
396 act.sa_flags = SA_NODEFER | SA_RESTART | SA_SIGINFO;
397 sigemptyset (&act.sa_mask);
398
399 /* Do not install handlers if interrupt state is "System". */
400 if (__gnat_get_interrupt_state (SIGABRT) != 's')
401 sigaction (SIGABRT, &act, NULL);
402 if (__gnat_get_interrupt_state (SIGFPE) != 's')
403 sigaction (SIGFPE, &act, NULL);
404 if (__gnat_get_interrupt_state (SIGILL) != 's')
405 sigaction (SIGILL, &act, NULL);
406 if (__gnat_get_interrupt_state (SIGBUS) != 's')
407 sigaction (SIGBUS, &act, NULL);
408 act.sa_flags |= SA_ONSTACK;
409 if (__gnat_get_interrupt_state (SIGSEGV) != 's')
410 sigaction (SIGSEGV, &act, NULL);
411
412 __gnat_handler_installed = 1;
413 }
414
415 /*********************/
416 /* GNU/Linux Section */
417 /*********************/
418
419 #elif defined (linux)
420
421 #include <signal.h>
422
423 #define __USE_GNU 1 /* required to get REG_EIP/RIP from glibc's ucontext.h */
424 #include <sys/ucontext.h>
425
426 /* GNU/Linux, which uses glibc, does not define NULL in included
427 header files. */
428
429 #if !defined (NULL)
430 #define NULL ((void *) 0)
431 #endif
432
433 #if defined (MaRTE)
434
435 /* MaRTE OS provides its own version of sigaction, sigfillset, and
436 sigemptyset (overriding these symbol names). We want to make sure that
437 the versions provided by the underlying C library are used here (these
438 versions are renamed by MaRTE to linux_sigaction, fake_linux_sigfillset,
439 and fake_linux_sigemptyset, respectively). The MaRTE library will not
440 always be present (it will not be linked if no tasking constructs are
441 used), so we use the weak symbol mechanism to point always to the symbols
442 defined within the C library. */
443
444 #pragma weak linux_sigaction
445 int linux_sigaction (int signum, const struct sigaction *act,
446 struct sigaction *oldact) {
447 return sigaction (signum, act, oldact);
448 }
449 #define sigaction(signum, act, oldact) linux_sigaction (signum, act, oldact)
450
451 #pragma weak fake_linux_sigfillset
452 void fake_linux_sigfillset (sigset_t *set) {
453 sigfillset (set);
454 }
455 #define sigfillset(set) fake_linux_sigfillset (set)
456
457 #pragma weak fake_linux_sigemptyset
458 void fake_linux_sigemptyset (sigset_t *set) {
459 sigemptyset (set);
460 }
461 #define sigemptyset(set) fake_linux_sigemptyset (set)
462
463 #endif
464
465 #if defined (i386) || defined (__x86_64__) || defined (__ia64__)
466
467 #define HAVE_GNAT_ADJUST_CONTEXT_FOR_RAISE
468
469 void
470 __gnat_adjust_context_for_raise (int signo ATTRIBUTE_UNUSED, void *ucontext)
471 {
472 mcontext_t *mcontext = &((ucontext_t *) ucontext)->uc_mcontext;
473
474 /* On the i386 and x86-64 architectures, stack checking is performed by
475 means of probes with moving stack pointer, that is to say the probed
476 address is always the value of the stack pointer. Upon hitting the
477 guard page, the stack pointer therefore points to an inaccessible
478 address and an alternate signal stack is needed to run the handler.
479 But there is an additional twist: on these architectures, the EH
480 return code writes the address of the handler at the target CFA's
481 value on the stack before doing the jump. As a consequence, if
482 there is an active handler in the frame whose stack has overflowed,
483 the stack pointer must nevertheless point to an accessible address
484 by the time the EH return is executed.
485
486 We therefore adjust the saved value of the stack pointer by the size
487 of one page + a small dope of 4 words, in order to make sure that it
488 points to an accessible address in case it's used as the target CFA.
489 The stack checking code guarantees that this address is unused by the
490 time this happens. */
491
492 #if defined (i386)
493 unsigned long *pc = (unsigned long *)mcontext->gregs[REG_EIP];
494 /* The pattern is "orl $0x0,(%esp)" for a probe in 32-bit mode. */
495 if (signo == SIGSEGV && pc && *pc == 0x00240c83)
496 mcontext->gregs[REG_ESP] += 4096 + 4 * sizeof (unsigned long);
497 #elif defined (__x86_64__)
498 unsigned long long *pc = (unsigned long long *)mcontext->gregs[REG_RIP];
499 if (signo == SIGSEGV && pc
500 /* The pattern is "orq $0x0,(%rsp)" for a probe in 64-bit mode. */
501 && ((*pc & 0xffffffffffLL) == 0x00240c8348LL
502 /* The pattern may also be "orl $0x0,(%esp)" for a probe in
503 x32 mode. */
504 || (*pc & 0xffffffffLL) == 0x00240c83LL))
505 mcontext->gregs[REG_RSP] += 4096 + 4 * sizeof (unsigned long);
506 #elif defined (__ia64__)
507 /* ??? The IA-64 unwinder doesn't compensate for signals. */
508 mcontext->sc_ip++;
509 #endif
510 }
511
512 #endif
513
514 static void
515 __gnat_error_handler (int sig, siginfo_t *si ATTRIBUTE_UNUSED, void *ucontext)
516 {
517 struct Exception_Data *exception;
518 const char *msg;
519
520 /* Adjusting is required for every fault context, so adjust for this one
521 now, before we possibly trigger a recursive fault below. */
522 __gnat_adjust_context_for_raise (sig, ucontext);
523
524 switch (sig)
525 {
526 case SIGSEGV:
527 /* Here we would like a discrimination test to see whether the page
528 before the faulting address is accessible. Unfortunately, Linux
529 seems to have no way of giving us the faulting address.
530
531 In old versions of init.c, we had a test of the page before the
532 stack pointer:
533
534 ((volatile char *)
535 ((long) si->esp_at_signal & - getpagesize ()))[getpagesize ()];
536
537 but that's wrong since it tests the stack pointer location and the
538 stack probing code may not move it until all probes succeed.
539
540 For now we simply do not attempt any discrimination at all. Note
541 that this is quite acceptable, since a "real" SIGSEGV can only
542 occur as the result of an erroneous program. */
543 exception = &storage_error;
544 msg = "stack overflow or erroneous memory access";
545 break;
546
547 case SIGBUS:
548 exception = &storage_error;
549 msg = "SIGBUS: possible stack overflow";
550 break;
551
552 case SIGFPE:
553 exception = &constraint_error;
554 msg = "SIGFPE";
555 break;
556
557 default:
558 exception = &program_error;
559 msg = "unhandled signal";
560 }
561
562 Raise_From_Signal_Handler (exception, msg);
563 }
564
565 #if defined (i386) || defined (__x86_64__) || defined (__powerpc__)
566 /* This must be in keeping with System.OS_Interface.Alternate_Stack_Size. */
567 char __gnat_alternate_stack[16 * 1024]; /* 2 * SIGSTKSZ */
568 #endif
569
570 #ifdef __XENO__
571 #include <sys/mman.h>
572 #include <native/task.h>
573
574 RT_TASK main_task;
575 #endif
576
577 void
578 __gnat_install_handler (void)
579 {
580 struct sigaction act;
581
582 #ifdef __XENO__
583 int prio;
584
585 if (__gl_main_priority == -1)
586 prio = 49;
587 else
588 prio = __gl_main_priority;
589
590 /* Avoid memory swapping for this program */
591
592 mlockall (MCL_CURRENT|MCL_FUTURE);
593
594 /* Turn the current Linux task into a native Xenomai task */
595
596 rt_task_shadow(&main_task, "environment_task", prio, T_FPU);
597 #endif
598
599 /* Set up signal handler to map synchronous signals to appropriate
600 exceptions. Make sure that the handler isn't interrupted by another
601 signal that might cause a scheduling event! Also setup an alternate
602 stack region for the handler execution so that stack overflows can be
603 handled properly, avoiding a SEGV generation from stack usage by the
604 handler itself. */
605
606 #if defined (i386) || defined (__x86_64__) || defined (__powerpc__)
607 stack_t stack;
608 stack.ss_sp = __gnat_alternate_stack;
609 stack.ss_size = sizeof (__gnat_alternate_stack);
610 stack.ss_flags = 0;
611 sigaltstack (&stack, NULL);
612 #endif
613
614 act.sa_sigaction = __gnat_error_handler;
615 act.sa_flags = SA_NODEFER | SA_RESTART | SA_SIGINFO;
616 sigemptyset (&act.sa_mask);
617
618 /* Do not install handlers if interrupt state is "System". */
619 if (__gnat_get_interrupt_state (SIGABRT) != 's')
620 sigaction (SIGABRT, &act, NULL);
621 if (__gnat_get_interrupt_state (SIGFPE) != 's')
622 sigaction (SIGFPE, &act, NULL);
623 if (__gnat_get_interrupt_state (SIGILL) != 's')
624 sigaction (SIGILL, &act, NULL);
625 if (__gnat_get_interrupt_state (SIGBUS) != 's')
626 sigaction (SIGBUS, &act, NULL);
627 #if defined (i386) || defined (__x86_64__) || defined (__powerpc__)
628 act.sa_flags |= SA_ONSTACK;
629 #endif
630 if (__gnat_get_interrupt_state (SIGSEGV) != 's')
631 sigaction (SIGSEGV, &act, NULL);
632
633 __gnat_handler_installed = 1;
634 }
635
636 /*******************/
637 /* LynxOS Section */
638 /*******************/
639
640 #elif defined (__Lynx__)
641
642 #include <signal.h>
643 #include <unistd.h>
644
645 static void
646 __gnat_error_handler (int sig)
647 {
648 struct Exception_Data *exception;
649 const char *msg;
650
651 switch(sig)
652 {
653 case SIGFPE:
654 exception = &constraint_error;
655 msg = "SIGFPE";
656 break;
657 case SIGILL:
658 exception = &constraint_error;
659 msg = "SIGILL";
660 break;
661 case SIGSEGV:
662 exception = &storage_error;
663 msg = "stack overflow or erroneous memory access";
664 break;
665 case SIGBUS:
666 exception = &constraint_error;
667 msg = "SIGBUS";
668 break;
669 default:
670 exception = &program_error;
671 msg = "unhandled signal";
672 }
673
674 Raise_From_Signal_Handler(exception, msg);
675 }
676
677 void
678 __gnat_install_handler(void)
679 {
680 struct sigaction act;
681
682 act.sa_handler = __gnat_error_handler;
683 act.sa_flags = 0x0;
684 sigemptyset (&act.sa_mask);
685
686 /* Do not install handlers if interrupt state is "System". */
687 if (__gnat_get_interrupt_state (SIGFPE) != 's')
688 sigaction (SIGFPE, &act, NULL);
689 if (__gnat_get_interrupt_state (SIGILL) != 's')
690 sigaction (SIGILL, &act, NULL);
691 if (__gnat_get_interrupt_state (SIGSEGV) != 's')
692 sigaction (SIGSEGV, &act, NULL);
693 if (__gnat_get_interrupt_state (SIGBUS) != 's')
694 sigaction (SIGBUS, &act, NULL);
695
696 __gnat_handler_installed = 1;
697 }
698
699 /*******************/
700 /* Solaris Section */
701 /*******************/
702
703 #elif defined (sun) && defined (__SVR4) && !defined (__vxworks)
704
705 #include <signal.h>
706 #include <siginfo.h>
707 #include <sys/ucontext.h>
708 #include <sys/regset.h>
709
710 /* The code below is common to SPARC and x86. Beware of the delay slot
711 differences for signal context adjustments. */
712
713 #if defined (__sparc)
714 #define RETURN_ADDR_OFFSET 8
715 #else
716 #define RETURN_ADDR_OFFSET 0
717 #endif
718
719 static void
720 __gnat_error_handler (int sig, siginfo_t *si, void *ucontext ATTRIBUTE_UNUSED)
721 {
722 struct Exception_Data *exception;
723 static int recurse = 0;
724 const char *msg;
725
726 switch (sig)
727 {
728 case SIGSEGV:
729 /* If the problem was permissions, this is a constraint error.
730 Likewise if the failing address isn't maximally aligned or if
731 we've recursed.
732
733 ??? Using a static variable here isn't task-safe, but it's
734 much too hard to do anything else and we're just determining
735 which exception to raise. */
736 if (si->si_code == SEGV_ACCERR
737 || (long) si->si_addr == 0
738 || (((long) si->si_addr) & 3) != 0
739 || recurse)
740 {
741 exception = &constraint_error;
742 msg = "SIGSEGV";
743 }
744 else
745 {
746 /* See if the page before the faulting page is accessible. Do that
747 by trying to access it. We'd like to simply try to access
748 4096 + the faulting address, but it's not guaranteed to be
749 the actual address, just to be on the same page. */
750 recurse++;
751 ((volatile char *)
752 ((long) si->si_addr & - getpagesize ()))[getpagesize ()];
753 exception = &storage_error;
754 msg = "stack overflow or erroneous memory access";
755 }
756 break;
757
758 case SIGBUS:
759 exception = &program_error;
760 msg = "SIGBUS";
761 break;
762
763 case SIGFPE:
764 exception = &constraint_error;
765 msg = "SIGFPE";
766 break;
767
768 default:
769 exception = &program_error;
770 msg = "unhandled signal";
771 }
772
773 recurse = 0;
774 Raise_From_Signal_Handler (exception, msg);
775 }
776
777 void
778 __gnat_install_handler (void)
779 {
780 struct sigaction act;
781
782 /* Set up signal handler to map synchronous signals to appropriate
783 exceptions. Make sure that the handler isn't interrupted by another
784 signal that might cause a scheduling event! */
785
786 act.sa_sigaction = __gnat_error_handler;
787 act.sa_flags = SA_NODEFER | SA_RESTART | SA_SIGINFO;
788 sigemptyset (&act.sa_mask);
789
790 /* Do not install handlers if interrupt state is "System". */
791 if (__gnat_get_interrupt_state (SIGABRT) != 's')
792 sigaction (SIGABRT, &act, NULL);
793 if (__gnat_get_interrupt_state (SIGFPE) != 's')
794 sigaction (SIGFPE, &act, NULL);
795 if (__gnat_get_interrupt_state (SIGSEGV) != 's')
796 sigaction (SIGSEGV, &act, NULL);
797 if (__gnat_get_interrupt_state (SIGBUS) != 's')
798 sigaction (SIGBUS, &act, NULL);
799
800 __gnat_handler_installed = 1;
801 }
802
803 /***************/
804 /* VMS Section */
805 /***************/
806
807 #elif defined (VMS)
808
809 /* Routine called from binder to override default feature values. */
810 void __gnat_set_features (void);
811 int __gnat_features_set = 0;
812
813 #ifdef __IA64
814 #define lib_get_curr_invo_context LIB$I64_GET_CURR_INVO_CONTEXT
815 #define lib_get_prev_invo_context LIB$I64_GET_PREV_INVO_CONTEXT
816 #define lib_get_invo_handle LIB$I64_GET_INVO_HANDLE
817 #else
818 #define lib_get_curr_invo_context LIB$GET_CURR_INVO_CONTEXT
819 #define lib_get_prev_invo_context LIB$GET_PREV_INVO_CONTEXT
820 #define lib_get_invo_handle LIB$GET_INVO_HANDLE
821 #endif
822
823 /* Define macro symbols for the VMS conditions that become Ada exceptions.
824 It would be better to just include <ssdef.h> */
825
826 #define SS$_ACCVIO 12
827 #define SS$_HPARITH 1284
828 #define SS$_INTDIV 1156
829 #define SS$_STKOVF 1364
830 #define SS$_RESIGNAL 2328
831
832 #define MTH$_FLOOVEMAT 1475268 /* Some ACVC_21 CXA tests */
833
834 /* The following codes must be resignalled, and not handled here. */
835
836 /* These codes are in standard message libraries. */
837 extern int C$_SIGKILL;
838 extern int SS$_DEBUG;
839 extern int LIB$_KEYNOTFOU;
840 extern int LIB$_ACTIMAGE;
841
842 /* These codes are non standard, which is to say the author is
843 not sure if they are defined in the standard message libraries
844 so keep them as macros for now. */
845 #define RDB$_STREAM_EOF 20480426
846 #define FDL$_UNPRIKW 11829410
847 #define CMA$_EXIT_THREAD 4227492
848
849 struct cond_sigargs {
850 unsigned int sigarg;
851 unsigned int sigargval;
852 };
853
854 struct cond_subtests {
855 unsigned int num;
856 const struct cond_sigargs sigargs[];
857 };
858
859 struct cond_except {
860 unsigned int cond;
861 const struct Exception_Data *except;
862 unsigned int needs_adjust; /* 1 = adjust PC, 0 = no adjust */
863 const struct cond_subtests *subtests;
864 };
865
866 struct descriptor_s {
867 unsigned short len, mbz;
868 __char_ptr32 adr;
869 };
870
871 /* Conditions that don't have an Ada exception counterpart must raise
872 Non_Ada_Error. Since this is defined in s-auxdec, it should only be
873 referenced by user programs, not the compiler or tools. Hence the
874 #ifdef IN_RTS. */
875
876 #ifdef IN_RTS
877
878 #define Status_Error ada__io_exceptions__status_error
879 extern struct Exception_Data Status_Error;
880
881 #define Mode_Error ada__io_exceptions__mode_error
882 extern struct Exception_Data Mode_Error;
883
884 #define Name_Error ada__io_exceptions__name_error
885 extern struct Exception_Data Name_Error;
886
887 #define Use_Error ada__io_exceptions__use_error
888 extern struct Exception_Data Use_Error;
889
890 #define Device_Error ada__io_exceptions__device_error
891 extern struct Exception_Data Device_Error;
892
893 #define End_Error ada__io_exceptions__end_error
894 extern struct Exception_Data End_Error;
895
896 #define Data_Error ada__io_exceptions__data_error
897 extern struct Exception_Data Data_Error;
898
899 #define Layout_Error ada__io_exceptions__layout_error
900 extern struct Exception_Data Layout_Error;
901
902 #define Non_Ada_Error system__aux_dec__non_ada_error
903 extern struct Exception_Data Non_Ada_Error;
904
905 #define Coded_Exception system__vms_exception_table__coded_exception
906 extern struct Exception_Data *Coded_Exception (Exception_Code);
907
908 #define Base_Code_In system__vms_exception_table__base_code_in
909 extern Exception_Code Base_Code_In (Exception_Code);
910
911 /* DEC Ada exceptions are not defined in a header file, so they
912 must be declared. */
913
914 #define ADA$_ALREADY_OPEN 0x0031a594
915 #define ADA$_CONSTRAINT_ERRO 0x00318324
916 #define ADA$_DATA_ERROR 0x003192c4
917 #define ADA$_DEVICE_ERROR 0x003195e4
918 #define ADA$_END_ERROR 0x00319904
919 #define ADA$_FAC_MODE_MISMAT 0x0031a8b3
920 #define ADA$_IOSYSFAILED 0x0031af04
921 #define ADA$_KEYSIZERR 0x0031aa3c
922 #define ADA$_KEY_MISMATCH 0x0031a8e3
923 #define ADA$_LAYOUT_ERROR 0x00319c24
924 #define ADA$_LINEXCMRS 0x0031a8f3
925 #define ADA$_MAXLINEXC 0x0031a8eb
926 #define ADA$_MODE_ERROR 0x00319f44
927 #define ADA$_MRN_MISMATCH 0x0031a8db
928 #define ADA$_MRS_MISMATCH 0x0031a8d3
929 #define ADA$_NAME_ERROR 0x0031a264
930 #define ADA$_NOT_OPEN 0x0031a58c
931 #define ADA$_ORG_MISMATCH 0x0031a8bb
932 #define ADA$_PROGRAM_ERROR 0x00318964
933 #define ADA$_RAT_MISMATCH 0x0031a8cb
934 #define ADA$_RFM_MISMATCH 0x0031a8c3
935 #define ADA$_STAOVF 0x00318cac
936 #define ADA$_STATUS_ERROR 0x0031a584
937 #define ADA$_STORAGE_ERROR 0x00318c84
938 #define ADA$_UNSUPPORTED 0x0031a8ab
939 #define ADA$_USE_ERROR 0x0031a8a4
940
941 /* DEC Ada specific conditions. */
942 static const struct cond_except dec_ada_cond_except_table [] = {
943 {ADA$_PROGRAM_ERROR, &program_error, 0, 0},
944 {ADA$_USE_ERROR, &Use_Error, 0, 0},
945 {ADA$_KEYSIZERR, &program_error, 0, 0},
946 {ADA$_STAOVF, &storage_error, 0, 0},
947 {ADA$_CONSTRAINT_ERRO, &constraint_error, 0, 0},
948 {ADA$_IOSYSFAILED, &Device_Error, 0, 0},
949 {ADA$_LAYOUT_ERROR, &Layout_Error, 0, 0},
950 {ADA$_STORAGE_ERROR, &storage_error, 0, 0},
951 {ADA$_DATA_ERROR, &Data_Error, 0, 0},
952 {ADA$_DEVICE_ERROR, &Device_Error, 0, 0},
953 {ADA$_END_ERROR, &End_Error, 0, 0},
954 {ADA$_MODE_ERROR, &Mode_Error, 0, 0},
955 {ADA$_NAME_ERROR, &Name_Error, 0, 0},
956 {ADA$_STATUS_ERROR, &Status_Error, 0, 0},
957 {ADA$_NOT_OPEN, &Use_Error, 0, 0},
958 {ADA$_ALREADY_OPEN, &Use_Error, 0, 0},
959 {ADA$_USE_ERROR, &Use_Error, 0, 0},
960 {ADA$_UNSUPPORTED, &Use_Error, 0, 0},
961 {ADA$_FAC_MODE_MISMAT, &Use_Error, 0, 0},
962 {ADA$_ORG_MISMATCH, &Use_Error, 0, 0},
963 {ADA$_RFM_MISMATCH, &Use_Error, 0, 0},
964 {ADA$_RAT_MISMATCH, &Use_Error, 0, 0},
965 {ADA$_MRS_MISMATCH, &Use_Error, 0, 0},
966 {ADA$_MRN_MISMATCH, &Use_Error, 0, 0},
967 {ADA$_KEY_MISMATCH, &Use_Error, 0, 0},
968 {ADA$_MAXLINEXC, &constraint_error, 0, 0},
969 {ADA$_LINEXCMRS, &constraint_error, 0, 0},
970
971 #if 0
972 /* Already handled by a pragma Import_Exception
973 in Aux_IO_Exceptions */
974 {ADA$_LOCK_ERROR, &Lock_Error, 0, 0},
975 {ADA$_EXISTENCE_ERROR, &Existence_Error, 0, 0},
976 {ADA$_KEY_ERROR, &Key_Error, 0, 0},
977 #endif
978
979 {0, 0, 0, 0}
980 };
981
982 #endif /* IN_RTS */
983
984 /* Non-DEC Ada specific conditions that map to Ada exceptions. */
985
986 /* Subtest for ACCVIO Constraint_Error, kept for compatibility,
987 in hindsight should have just made ACCVIO == Storage_Error. */
988 #define ACCVIO_REASON_MASK 2
989 #define ACCVIO_VIRTUAL_ADDR 3
990 static const struct cond_subtests accvio_c_e =
991 {2, /* number of subtests below */
992 {
993 {ACCVIO_REASON_MASK, 0},
994 {ACCVIO_VIRTUAL_ADDR, 0}
995 }
996 };
997
998 /* Macro flag to adjust PC which gets off by one for some conditions,
999 not sure if this is reliably true, PC could be off by more for
1000 HPARITH for example, unless a trapb is inserted. */
1001 #define NEEDS_ADJUST 1
1002
1003 static const struct cond_except system_cond_except_table [] = {
1004 {MTH$_FLOOVEMAT, &constraint_error, 0, 0},
1005 {SS$_INTDIV, &constraint_error, 0, 0},
1006 {SS$_HPARITH, &constraint_error, NEEDS_ADJUST, 0},
1007 {SS$_ACCVIO, &constraint_error, NEEDS_ADJUST, &accvio_c_e},
1008 {SS$_ACCVIO, &storage_error, NEEDS_ADJUST, 0},
1009 {SS$_STKOVF, &storage_error, NEEDS_ADJUST, 0},
1010 {0, 0, 0, 0}
1011 };
1012
1013 /* To deal with VMS conditions and their mapping to Ada exceptions,
1014 the __gnat_error_handler routine below is installed as an exception
1015 vector having precedence over DEC frame handlers. Some conditions
1016 still need to be handled by such handlers, however, in which case
1017 __gnat_error_handler needs to return SS$_RESIGNAL. Consider for
1018 instance the use of a third party library compiled with DECAda and
1019 performing its own exception handling internally.
1020
1021 To allow some user-level flexibility, which conditions should be
1022 resignaled is controlled by a predicate function, provided with the
1023 condition value and returning a boolean indication stating whether
1024 this condition should be resignaled or not.
1025
1026 That predicate function is called indirectly, via a function pointer,
1027 by __gnat_error_handler, and changing that pointer is allowed to the
1028 user code by way of the __gnat_set_resignal_predicate interface.
1029
1030 The user level function may then implement what it likes, including
1031 for instance the maintenance of a dynamic data structure if the set
1032 of to be resignalled conditions has to change over the program's
1033 lifetime.
1034
1035 ??? This is not a perfect solution to deal with the possible
1036 interactions between the GNAT and the DECAda exception handling
1037 models and better (more general) schemes are studied. This is so
1038 just provided as a convenient workaround in the meantime, and
1039 should be use with caution since the implementation has been kept
1040 very simple. */
1041
1042 typedef int
1043 resignal_predicate (int code);
1044
1045 static const int * const cond_resignal_table [] = {
1046 &C$_SIGKILL,
1047 (int *)CMA$_EXIT_THREAD,
1048 &SS$_DEBUG,
1049 &LIB$_KEYNOTFOU,
1050 &LIB$_ACTIMAGE,
1051 (int *) RDB$_STREAM_EOF,
1052 (int *) FDL$_UNPRIKW,
1053 0
1054 };
1055
1056 static const int facility_resignal_table [] = {
1057 0x1380000, /* RDB */
1058 0x2220000, /* SQL */
1059 0
1060 };
1061
1062 /* Default GNAT predicate for resignaling conditions. */
1063
1064 static int
1065 __gnat_default_resignal_p (int code)
1066 {
1067 int i, iexcept;
1068
1069 for (i = 0; facility_resignal_table [i]; i++)
1070 if ((code & 0xfff0000) == facility_resignal_table [i])
1071 return 1;
1072
1073 for (i = 0, iexcept = 0;
1074 cond_resignal_table [i]
1075 && !(iexcept = LIB$MATCH_COND (&code, &cond_resignal_table [i]));
1076 i++);
1077
1078 return iexcept;
1079 }
1080
1081 /* Static pointer to predicate that the __gnat_error_handler exception
1082 vector invokes to determine if it should resignal a condition. */
1083
1084 static resignal_predicate *__gnat_resignal_p = __gnat_default_resignal_p;
1085
1086 /* User interface to change the predicate pointer to PREDICATE. Reset to
1087 the default if PREDICATE is null. */
1088
1089 void
1090 __gnat_set_resignal_predicate (resignal_predicate *predicate)
1091 {
1092 if (predicate == NULL)
1093 __gnat_resignal_p = __gnat_default_resignal_p;
1094 else
1095 __gnat_resignal_p = predicate;
1096 }
1097
1098 /* Should match System.Parameters.Default_Exception_Msg_Max_Length. */
1099 #define Default_Exception_Msg_Max_Length 512
1100
1101 /* Action routine for SYS$PUTMSG. There may be multiple
1102 conditions, each with text to be appended to MESSAGE
1103 and separated by line termination. */
1104
1105 static int
1106 copy_msg (struct descriptor_s *msgdesc, char *message)
1107 {
1108 int len = strlen (message);
1109 int copy_len;
1110
1111 /* Check for buffer overflow and skip. */
1112 if (len > 0 && len <= Default_Exception_Msg_Max_Length - 3)
1113 {
1114 strcat (message, "\r\n");
1115 len += 2;
1116 }
1117
1118 /* Check for buffer overflow and truncate if necessary. */
1119 copy_len = (len + msgdesc->len <= Default_Exception_Msg_Max_Length - 1 ?
1120 msgdesc->len :
1121 Default_Exception_Msg_Max_Length - 1 - len);
1122 strncpy (&message [len], msgdesc->adr, copy_len);
1123 message [len + copy_len] = 0;
1124
1125 return 0;
1126 }
1127
1128 /* Scan TABLE for a match for the condition contained in SIGARGS,
1129 and return the entry, or the empty entry if no match found. */
1130
1131 static const struct cond_except *
1132 scan_conditions ( int *sigargs, const struct cond_except *table [])
1133 {
1134 int i;
1135 struct cond_except entry;
1136
1137 /* Scan the exception condition table for a match and fetch
1138 the associated GNAT exception pointer. */
1139 for (i = 0; (*table) [i].cond; i++)
1140 {
1141 unsigned int match = LIB$MATCH_COND (&sigargs [1], &(*table) [i].cond);
1142 const struct cond_subtests *subtests = (*table) [i].subtests;
1143
1144 if (match)
1145 {
1146 if (!subtests)
1147 {
1148 return &(*table) [i];
1149 }
1150 else
1151 {
1152 unsigned int ii;
1153 int num = (*subtests).num;
1154
1155 /* Perform subtests to differentiate exception. */
1156 for (ii = 0; ii < num; ii++)
1157 {
1158 unsigned int arg = (*subtests).sigargs [ii].sigarg;
1159 unsigned int argval = (*subtests).sigargs [ii].sigargval;
1160
1161 if (sigargs [arg] != argval)
1162 {
1163 num = 0;
1164 break;
1165 }
1166 }
1167
1168 /* All subtests passed. */
1169 if (num == (*subtests).num)
1170 return &(*table) [i];
1171 }
1172 }
1173 }
1174
1175 /* No match, return the null terminating entry. */
1176 return &(*table) [i];
1177 }
1178
1179 long
1180 __gnat_handle_vms_condition (int *sigargs, void *mechargs)
1181 {
1182 struct Exception_Data *exception = 0;
1183 unsigned int needs_adjust = 0;
1184 Exception_Code base_code;
1185 struct descriptor_s gnat_facility = {4, 0, "GNAT"};
1186 char message [Default_Exception_Msg_Max_Length];
1187
1188 const char *msg = "";
1189
1190 /* Check for conditions to resignal which aren't effected by pragma
1191 Import_Exception. */
1192 if (__gnat_resignal_p (sigargs [1]))
1193 return SS$_RESIGNAL;
1194 #ifndef IN_RTS
1195 /* toplev.c handles this for compiler. */
1196 if (sigargs [1] == SS$_HPARITH)
1197 return SS$_RESIGNAL;
1198 #endif
1199
1200 #ifdef IN_RTS
1201 /* See if it's an imported exception. Beware that registered exceptions
1202 are bound to their base code, with the severity bits masked off. */
1203 base_code = Base_Code_In ((Exception_Code) sigargs[1]);
1204 exception = Coded_Exception (base_code);
1205 #endif
1206
1207 if (exception == 0)
1208 #ifdef IN_RTS
1209 {
1210 int i;
1211 struct cond_except cond;
1212 const struct cond_except *cond_table;
1213 const struct cond_except *cond_tables [] = {dec_ada_cond_except_table,
1214 system_cond_except_table,
1215 0};
1216
1217 i = 0;
1218 while ((cond_table = cond_tables[i++]) && !exception)
1219 {
1220 cond = *scan_conditions (sigargs, &cond_table);
1221 exception = (struct Exception_Data *) cond.except;
1222 }
1223
1224 if (exception)
1225 needs_adjust = cond.needs_adjust;
1226 else
1227 /* User programs expect Non_Ada_Error to be raised if no match,
1228 reference DEC Ada test CXCONDHAN. */
1229 exception = &Non_Ada_Error;
1230 }
1231 #else
1232 {
1233 /* Pretty much everything is just a program error in the compiler */
1234 exception = &program_error;
1235 }
1236 #endif
1237
1238 message[0] = 0;
1239 /* Subtract PC & PSL fields as per ABI for SYS$PUTMSG. */
1240 sigargs[0] -= 2;
1241 SYS$PUTMSG (sigargs, copy_msg, &gnat_facility, message);
1242 /* Add back PC & PSL fields as per ABI for SYS$PUTMSG. */
1243 sigargs[0] += 2;
1244 msg = message;
1245
1246 if (needs_adjust)
1247 __gnat_adjust_context_for_raise (sigargs [1], (void *)mechargs);
1248
1249 Raise_From_Signal_Handler (exception, msg);
1250 }
1251
1252 void
1253 __gnat_install_handler (void)
1254 {
1255 long prvhnd ATTRIBUTE_UNUSED;
1256
1257 #if !defined (IN_RTS)
1258 SYS$SETEXV (1, __gnat_handle_vms_condition, 3, &prvhnd);
1259 #endif
1260
1261 __gnat_handler_installed = 1;
1262 }
1263
1264 /* __gnat_adjust_context_for_raise for Alpha - see comments along with the
1265 default version later in this file. */
1266
1267 #if defined (IN_RTS) && defined (__alpha__)
1268
1269 #include <vms/chfctxdef.h>
1270 #include <vms/chfdef.h>
1271
1272 #define HAVE_GNAT_ADJUST_CONTEXT_FOR_RAISE
1273
1274 void
1275 __gnat_adjust_context_for_raise (int signo ATTRIBUTE_UNUSED, void *ucontext)
1276 {
1277 if (signo == SS$_HPARITH)
1278 {
1279 /* Sub one to the address of the instruction signaling the condition,
1280 located in the sigargs array. */
1281
1282 CHF$MECH_ARRAY * mechargs = (CHF$MECH_ARRAY *) ucontext;
1283 CHF$SIGNAL_ARRAY * sigargs
1284 = (CHF$SIGNAL_ARRAY *) mechargs->chf$q_mch_sig_addr;
1285
1286 int vcount = sigargs->chf$is_sig_args;
1287 int * pc_slot = & (&sigargs->chf$l_sig_name)[vcount-2];
1288
1289 (*pc_slot)--;
1290 }
1291 }
1292
1293 #endif
1294
1295 /* __gnat_adjust_context_for_raise for ia64. */
1296
1297 #if defined (IN_RTS) && defined (__IA64)
1298
1299 #include <vms/chfctxdef.h>
1300 #include <vms/chfdef.h>
1301
1302 #define HAVE_GNAT_ADJUST_CONTEXT_FOR_RAISE
1303
1304 typedef unsigned long long u64;
1305
1306 void
1307 __gnat_adjust_context_for_raise (int signo ATTRIBUTE_UNUSED, void *ucontext)
1308 {
1309 /* Add one to the address of the instruction signaling the condition,
1310 located in the 64bits sigargs array. */
1311
1312 CHF$MECH_ARRAY * mechargs = (CHF$MECH_ARRAY *) ucontext;
1313
1314 CHF64$SIGNAL_ARRAY *chfsig64
1315 = (CHF64$SIGNAL_ARRAY *) mechargs->chf$ph_mch_sig64_addr;
1316
1317 u64 * post_sigarray
1318 = (u64 *)chfsig64 + 1 + chfsig64->chf64$l_sig_args;
1319
1320 u64 * ih_pc_loc = post_sigarray - 2;
1321
1322 (*ih_pc_loc) ++;
1323 }
1324
1325 #endif
1326
1327 /* Easier interface for LIB$GET_LOGICAL: put the equivalence of NAME into BUF,
1328 always NUL terminated. In case of error or if the result is longer than
1329 LEN (length of BUF) an empty string is written info BUF. */
1330
1331 static void
1332 __gnat_vms_get_logical (const char *name, char *buf, int len)
1333 {
1334 struct descriptor_s name_desc, result_desc;
1335 int status;
1336 unsigned short rlen;
1337
1338 /* Build the descriptor for NAME. */
1339 name_desc.len = strlen (name);
1340 name_desc.mbz = 0;
1341 name_desc.adr = (char *)name;
1342
1343 /* Build the descriptor for the result. */
1344 result_desc.len = len;
1345 result_desc.mbz = 0;
1346 result_desc.adr = buf;
1347
1348 status = LIB$GET_LOGICAL (&name_desc, &result_desc, &rlen);
1349
1350 if ((status & 1) == 1 && rlen < len)
1351 buf[rlen] = 0;
1352 else
1353 buf[0] = 0;
1354 }
1355
1356 /* Size of a page on ia64 and alpha VMS. */
1357 #define VMS_PAGESIZE 8192
1358
1359 /* User mode. */
1360 #define PSL__C_USER 3
1361
1362 /* No access. */
1363 #define PRT__C_NA 0
1364
1365 /* Descending region. */
1366 #define VA__M_DESCEND 1
1367
1368 /* Get by virtual address. */
1369 #define VA___REGSUM_BY_VA 1
1370
1371 /* Memory region summary. */
1372 struct regsum
1373 {
1374 unsigned long long q_region_id;
1375 unsigned int l_flags;
1376 unsigned int l_region_protection;
1377 void *pq_start_va;
1378 unsigned long long q_region_size;
1379 void *pq_first_free_va;
1380 };
1381
1382 extern int SYS$GET_REGION_INFO (unsigned int, unsigned long long *,
1383 void *, void *, unsigned int,
1384 void *, unsigned int *);
1385 extern int SYS$EXPREG_64 (unsigned long long *, unsigned long long,
1386 unsigned int, unsigned int, void **,
1387 unsigned long long *);
1388 extern int SYS$SETPRT_64 (void *, unsigned long long, unsigned int,
1389 unsigned int, void **, unsigned long long *,
1390 unsigned int *);
1391 extern int SYS$PUTMSG (void *, int (*)(), void *, unsigned long long);
1392
1393 /* Add a guard page in the memory region containing ADDR at ADDR +/- SIZE.
1394 (The sign depends on the kind of the memory region). */
1395
1396 static int
1397 __gnat_set_stack_guard_page (void *addr, unsigned long size)
1398 {
1399 int status;
1400 void *ret_va;
1401 unsigned long long ret_len;
1402 unsigned int ret_prot;
1403 void *start_va;
1404 unsigned long long length;
1405 unsigned int retlen;
1406 struct regsum buffer;
1407
1408 /* Get the region for ADDR. */
1409 status = SYS$GET_REGION_INFO
1410 (VA___REGSUM_BY_VA, NULL, addr, NULL, sizeof (buffer), &buffer, &retlen);
1411
1412 if ((status & 1) != 1)
1413 return -1;
1414
1415 /* Extend the region. */
1416 status = SYS$EXPREG_64 (&buffer.q_region_id,
1417 size, 0, 0, &start_va, &length);
1418
1419 if ((status & 1) != 1)
1420 return -1;
1421
1422 /* Create a guard page. */
1423 if (!(buffer.l_flags & VA__M_DESCEND))
1424 start_va = (void *)((unsigned long long)start_va + length - VMS_PAGESIZE);
1425
1426 status = SYS$SETPRT_64 (start_va, VMS_PAGESIZE, PSL__C_USER, PRT__C_NA,
1427 &ret_va, &ret_len, &ret_prot);
1428
1429 if ((status & 1) != 1)
1430 return -1;
1431 return 0;
1432 }
1433
1434 /* Read logicals to limit the stack(s) size. */
1435
1436 static void
1437 __gnat_set_stack_limit (void)
1438 {
1439 #ifdef __ia64__
1440 void *sp;
1441 unsigned long size;
1442 char value[16];
1443 char *e;
1444
1445 /* The main stack. */
1446 __gnat_vms_get_logical ("GNAT_STACK_SIZE", value, sizeof (value));
1447 size = strtoul (value, &e, 0);
1448 if (e > value && *e == 0)
1449 {
1450 asm ("mov %0=sp" : "=r" (sp));
1451 __gnat_set_stack_guard_page (sp, size * 1024);
1452 }
1453
1454 /* The register stack. */
1455 __gnat_vms_get_logical ("GNAT_RBS_SIZE", value, sizeof (value));
1456 size = strtoul (value, &e, 0);
1457 if (e > value && *e == 0)
1458 {
1459 asm ("mov %0=ar.bsp" : "=r" (sp));
1460 __gnat_set_stack_guard_page (sp, size * 1024);
1461 }
1462 #endif
1463 }
1464
1465 /* Feature logical name and global variable address pair.
1466 If we ever add another feature logical to this list, the
1467 feature struct will need to be enhanced to take into account
1468 possible values for *gl_addr. */
1469 struct feature {
1470 const char *name;
1471 int *gl_addr;
1472 };
1473
1474 /* Default values for GNAT features set by environment. */
1475 int __gl_heap_size = 64;
1476
1477 /* Array feature logical names and global variable addresses. */
1478 static const struct feature features[] = {
1479 {"GNAT$NO_MALLOC_64", &__gl_heap_size},
1480 {0, 0}
1481 };
1482
1483 void
1484 __gnat_set_features (void)
1485 {
1486 int i;
1487 char buff[16];
1488
1489 /* Loop through features array and test name for enable/disable. */
1490 for (i = 0; features[i].name; i++)
1491 {
1492 __gnat_vms_get_logical (features[i].name, buff, sizeof (buff));
1493
1494 if (strcmp (buff, "ENABLE") == 0
1495 || strcmp (buff, "TRUE") == 0
1496 || strcmp (buff, "1") == 0)
1497 *features[i].gl_addr = 32;
1498 else if (strcmp (buff, "DISABLE") == 0
1499 || strcmp (buff, "FALSE") == 0
1500 || strcmp (buff, "0") == 0)
1501 *features[i].gl_addr = 64;
1502 }
1503
1504 /* Features to artificially limit the stack size. */
1505 __gnat_set_stack_limit ();
1506
1507 __gnat_features_set = 1;
1508 }
1509
1510 /* Return true if the VMS version is 7.x. */
1511
1512 extern unsigned int LIB$GETSYI (int *, ...);
1513
1514 #define SYI$_VERSION 0x1000
1515
1516 int
1517 __gnat_is_vms_v7 (void)
1518 {
1519 struct descriptor_s desc;
1520 char version[8];
1521 int status;
1522 int code = SYI$_VERSION;
1523
1524 desc.len = sizeof (version);
1525 desc.mbz = 0;
1526 desc.adr = version;
1527
1528 status = LIB$GETSYI (&code, 0, &desc);
1529 if ((status & 1) == 1 && version[1] == '7' && version[2] == '.')
1530 return 1;
1531 else
1532 return 0;
1533 }
1534
1535 /*******************/
1536 /* FreeBSD Section */
1537 /*******************/
1538
1539 #elif defined (__FreeBSD__)
1540
1541 #include <signal.h>
1542 #include <sys/ucontext.h>
1543 #include <unistd.h>
1544
1545 static void
1546 __gnat_error_handler (int sig,
1547 siginfo_t *si ATTRIBUTE_UNUSED,
1548 void *ucontext ATTRIBUTE_UNUSED)
1549 {
1550 struct Exception_Data *exception;
1551 const char *msg;
1552
1553 switch (sig)
1554 {
1555 case SIGFPE:
1556 exception = &constraint_error;
1557 msg = "SIGFPE";
1558 break;
1559
1560 case SIGILL:
1561 exception = &constraint_error;
1562 msg = "SIGILL";
1563 break;
1564
1565 case SIGSEGV:
1566 exception = &storage_error;
1567 msg = "stack overflow or erroneous memory access";
1568 break;
1569
1570 case SIGBUS:
1571 exception = &storage_error;
1572 msg = "SIGBUS: possible stack overflow";
1573 break;
1574
1575 default:
1576 exception = &program_error;
1577 msg = "unhandled signal";
1578 }
1579
1580 Raise_From_Signal_Handler (exception, msg);
1581 }
1582
1583 void
1584 __gnat_install_handler ()
1585 {
1586 struct sigaction act;
1587
1588 /* Set up signal handler to map synchronous signals to appropriate
1589 exceptions. Make sure that the handler isn't interrupted by another
1590 signal that might cause a scheduling event! */
1591
1592 act.sa_sigaction
1593 = (void (*)(int, struct __siginfo *, void*)) __gnat_error_handler;
1594 act.sa_flags = SA_NODEFER | SA_RESTART | SA_SIGINFO;
1595 (void) sigemptyset (&act.sa_mask);
1596
1597 (void) sigaction (SIGILL, &act, NULL);
1598 (void) sigaction (SIGFPE, &act, NULL);
1599 (void) sigaction (SIGSEGV, &act, NULL);
1600 (void) sigaction (SIGBUS, &act, NULL);
1601
1602 __gnat_handler_installed = 1;
1603 }
1604
1605 /*******************/
1606 /* VxWorks Section */
1607 /*******************/
1608
1609 #elif defined(__vxworks)
1610
1611 #include <signal.h>
1612 #include <taskLib.h>
1613
1614 #ifndef __RTP__
1615 #include <intLib.h>
1616 #include <iv.h>
1617 #endif
1618
1619 #ifdef VTHREADS
1620 #include "private/vThreadsP.h"
1621 #endif
1622
1623 void __gnat_error_handler (int, void *, struct sigcontext *);
1624
1625 #ifndef __RTP__
1626
1627 /* Directly vectored Interrupt routines are not supported when using RTPs. */
1628
1629 extern int __gnat_inum_to_ivec (int);
1630
1631 /* This is needed by the GNAT run time to handle Vxworks interrupts. */
1632 int
1633 __gnat_inum_to_ivec (int num)
1634 {
1635 return INUM_TO_IVEC (num);
1636 }
1637 #endif
1638
1639 #if !defined(__alpha_vxworks) && (_WRS_VXWORKS_MAJOR != 6) && !defined(__RTP__)
1640
1641 /* getpid is used by s-parint.adb, but is not defined by VxWorks, except
1642 on Alpha VxWorks and VxWorks 6.x (including RTPs). */
1643
1644 extern long getpid (void);
1645
1646 long
1647 getpid (void)
1648 {
1649 return taskIdSelf ();
1650 }
1651 #endif
1652
1653 /* VxWorks 653 vThreads expects the field excCnt to be zeroed when a signal is.
1654 handled. The VxWorks version of longjmp does this; GCC's builtin_longjmp
1655 doesn't. */
1656 void
1657 __gnat_clear_exception_count (void)
1658 {
1659 #ifdef VTHREADS
1660 WIND_TCB *currentTask = (WIND_TCB *) taskIdSelf();
1661
1662 currentTask->vThreads.excCnt = 0;
1663 #endif
1664 }
1665
1666 /* Handle different SIGnal to exception mappings in different VxWorks
1667 versions. */
1668 static void
1669 __gnat_map_signal (int sig, void *si ATTRIBUTE_UNUSED,
1670 struct sigcontext *sc ATTRIBUTE_UNUSED)
1671 {
1672 struct Exception_Data *exception;
1673 const char *msg;
1674
1675 switch (sig)
1676 {
1677 case SIGFPE:
1678 exception = &constraint_error;
1679 msg = "SIGFPE";
1680 break;
1681 #ifdef VTHREADS
1682 #ifdef __VXWORKSMILS__
1683 case SIGILL:
1684 exception = &storage_error;
1685 msg = "SIGILL: possible stack overflow";
1686 break;
1687 case SIGSEGV:
1688 exception = &storage_error;
1689 msg = "SIGSEGV";
1690 break;
1691 case SIGBUS:
1692 exception = &program_error;
1693 msg = "SIGBUS";
1694 break;
1695 #else
1696 case SIGILL:
1697 exception = &constraint_error;
1698 msg = "Floating point exception or SIGILL";
1699 break;
1700 case SIGSEGV:
1701 exception = &storage_error;
1702 msg = "SIGSEGV";
1703 break;
1704 case SIGBUS:
1705 exception = &storage_error;
1706 msg = "SIGBUS: possible stack overflow";
1707 break;
1708 #endif
1709 #elif (_WRS_VXWORKS_MAJOR == 6)
1710 case SIGILL:
1711 exception = &constraint_error;
1712 msg = "SIGILL";
1713 break;
1714 #ifdef __RTP__
1715 /* In RTP mode a SIGSEGV is most likely due to a stack overflow,
1716 since stack checking uses the probing mechanism. */
1717 case SIGSEGV:
1718 exception = &storage_error;
1719 msg = "SIGSEGV: possible stack overflow";
1720 break;
1721 case SIGBUS:
1722 exception = &program_error;
1723 msg = "SIGBUS";
1724 break;
1725 #else
1726 /* VxWorks 6 kernel mode with probing. SIGBUS for guard page hit */
1727 case SIGSEGV:
1728 exception = &storage_error;
1729 msg = "SIGSEGV";
1730 break;
1731 case SIGBUS:
1732 exception = &storage_error;
1733 msg = "SIGBUS: possible stack overflow";
1734 break;
1735 #endif
1736 #else
1737 /* VxWorks 5: a SIGILL is most likely due to a stack overflow,
1738 since stack checking uses the stack limit mechanism. */
1739 case SIGILL:
1740 exception = &storage_error;
1741 msg = "SIGILL: possible stack overflow";
1742 break;
1743 case SIGSEGV:
1744 exception = &storage_error;
1745 msg = "SIGSEGV";
1746 break;
1747 case SIGBUS:
1748 exception = &program_error;
1749 msg = "SIGBUS";
1750 break;
1751 #endif
1752 default:
1753 exception = &program_error;
1754 msg = "unhandled signal";
1755 }
1756
1757 __gnat_clear_exception_count ();
1758 Raise_From_Signal_Handler (exception, msg);
1759 }
1760
1761 /* Tasking and Non-tasking signal handler. Map SIGnal to Ada exception
1762 propagation after the required low level adjustments. */
1763
1764 void
1765 __gnat_error_handler (int sig, void *si, struct sigcontext *sc)
1766 {
1767 sigset_t mask;
1768
1769 /* VxWorks will always mask out the signal during the signal handler and
1770 will reenable it on a longjmp. GNAT does not generate a longjmp to
1771 return from a signal handler so the signal will still be masked unless
1772 we unmask it. */
1773 sigprocmask (SIG_SETMASK, NULL, &mask);
1774 sigdelset (&mask, sig);
1775 sigprocmask (SIG_SETMASK, &mask, NULL);
1776
1777 #if defined (__PPC__) && defined(_WRS_KERNEL)
1778 /* On PowerPC, kernel mode, we process signals through a Call Frame Info
1779 trampoline, voiding the need for myriads of fallback_frame_state
1780 variants in the ZCX runtime. We have no simple way to distinguish ZCX
1781 from SJLJ here, so we do this for SJLJ as well even though this is not
1782 necessary. This only incurs a few extra instructions and a tiny
1783 amount of extra stack usage. */
1784
1785 #include "sigtramp.h"
1786
1787 __gnat_sigtramp (sig, (void *)si, (void *)sc,
1788 (sighandler_t *)&__gnat_map_signal);
1789
1790 #else
1791 __gnat_map_signal (sig, si, sc);
1792 #endif
1793 }
1794
1795 #if defined(__leon__) && defined(_WRS_KERNEL)
1796 /* For LEON VxWorks we need to install a trap handler for stack overflow */
1797
1798 extern void excEnt (void);
1799 /* VxWorks exception handler entry */
1800
1801 struct trap_entry {
1802 unsigned long inst_first;
1803 unsigned long inst_second;
1804 unsigned long inst_third;
1805 unsigned long inst_fourth;
1806 };
1807 /* Four instructions representing entries in the trap table */
1808
1809 struct trap_entry *trap_0_entry;
1810 /* We will set the location of the entry for software trap 0 in the trap
1811 table. */
1812 #endif
1813
1814 void
1815 __gnat_install_handler (void)
1816 {
1817 struct sigaction act;
1818
1819 /* Setup signal handler to map synchronous signals to appropriate
1820 exceptions. Make sure that the handler isn't interrupted by another
1821 signal that might cause a scheduling event! */
1822
1823 act.sa_handler = __gnat_error_handler;
1824 act.sa_flags = SA_SIGINFO | SA_ONSTACK;
1825 sigemptyset (&act.sa_mask);
1826
1827 /* For VxWorks, install all signal handlers, since pragma Interrupt_State
1828 applies to vectored hardware interrupts, not signals. */
1829 sigaction (SIGFPE, &act, NULL);
1830 sigaction (SIGILL, &act, NULL);
1831 sigaction (SIGSEGV, &act, NULL);
1832 sigaction (SIGBUS, &act, NULL);
1833
1834 #if defined(__leon__) && defined(_WRS_KERNEL)
1835 /* Specific to the LEON VxWorks kernel run-time library */
1836
1837 /* For stack checking the compiler triggers a software trap 0 (ta 0) in
1838 case of overflow (we use the stack limit mechanism). We need to install
1839 the trap handler here for this software trap (the OS does not handle
1840 it) as if it were a data_access_exception (trap 9). We do the same as
1841 if we put in the trap table a VXSPARC_BAD_TRAP(9). Software trap 0 is
1842 located at vector 0x80, and each entry takes 4 words. */
1843
1844 trap_0_entry = (struct trap_entry *)(intVecBaseGet () + 0x80 * 4);
1845
1846 /* mov 0x9, %l7 */
1847
1848 trap_0_entry->inst_first = 0xae102000 + 9;
1849
1850 /* sethi %hi(excEnt), %l6 */
1851
1852 /* The 22 most significant bits of excEnt are obtained shifting 10 times
1853 to the right. */
1854
1855 trap_0_entry->inst_second = 0x2d000000 + ((unsigned long)excEnt >> 10);
1856
1857 /* jmp %l6+%lo(excEnt) */
1858
1859 /* The 10 least significant bits of excEnt are obtained by masking */
1860
1861 trap_0_entry->inst_third = 0x81c5a000 + ((unsigned long)excEnt & 0x3ff);
1862
1863 /* rd %psr, %l0 */
1864
1865 trap_0_entry->inst_fourth = 0xa1480000;
1866 #endif
1867
1868 __gnat_handler_installed = 1;
1869 }
1870
1871 #define HAVE_GNAT_INIT_FLOAT
1872
1873 void
1874 __gnat_init_float (void)
1875 {
1876 /* Disable overflow/underflow exceptions on the PPC processor, needed
1877 to get correct Ada semantics. Note that for AE653 vThreads, the HW
1878 overflow settings are an OS configuration issue. The instructions
1879 below have no effect. */
1880 #if defined (_ARCH_PPC) && !defined (_SOFT_FLOAT) && (!defined (VTHREADS) || defined (__VXWORKSMILS__))
1881 #if defined (__SPE__)
1882 {
1883 const unsigned long spefscr_mask = 0xfffffff3;
1884 unsigned long spefscr;
1885 asm ("mfspr %0, 512" : "=r" (spefscr));
1886 spefscr = spefscr & spefscr_mask;
1887 asm ("mtspr 512, %0\n\tisync" : : "r" (spefscr));
1888 }
1889 #else
1890 asm ("mtfsb0 25");
1891 asm ("mtfsb0 26");
1892 #endif
1893 #endif
1894
1895 #if (defined (__i386__) || defined (i386)) && !defined (VTHREADS)
1896 /* This is used to properly initialize the FPU on an x86 for each
1897 process thread. */
1898 asm ("finit");
1899 #endif
1900
1901 /* Similarly for SPARC64. Achieved by masking bits in the Trap Enable Mask
1902 field of the Floating-point Status Register (see the SPARC Architecture
1903 Manual Version 9, p 48). */
1904 #if defined (sparc64)
1905
1906 #define FSR_TEM_NVM (1 << 27) /* Invalid operand */
1907 #define FSR_TEM_OFM (1 << 26) /* Overflow */
1908 #define FSR_TEM_UFM (1 << 25) /* Underflow */
1909 #define FSR_TEM_DZM (1 << 24) /* Division by Zero */
1910 #define FSR_TEM_NXM (1 << 23) /* Inexact result */
1911 {
1912 unsigned int fsr;
1913
1914 __asm__("st %%fsr, %0" : "=m" (fsr));
1915 fsr &= ~(FSR_TEM_OFM | FSR_TEM_UFM);
1916 __asm__("ld %0, %%fsr" : : "m" (fsr));
1917 }
1918 #endif
1919 }
1920
1921 /* This subprogram is called by System.Task_Primitives.Operations.Enter_Task
1922 (if not null) when a new task is created. It is initialized by
1923 System.Stack_Checking.Operations.Initialize_Stack_Limit.
1924 The use of a hook avoids to drag stack checking subprograms if stack
1925 checking is not used. */
1926 void (*__gnat_set_stack_limit_hook)(void) = (void (*)(void))0;
1927
1928 /******************/
1929 /* NetBSD Section */
1930 /******************/
1931
1932 #elif defined(__NetBSD__)
1933
1934 #include <signal.h>
1935 #include <unistd.h>
1936
1937 static void
1938 __gnat_error_handler (int sig)
1939 {
1940 struct Exception_Data *exception;
1941 const char *msg;
1942
1943 switch(sig)
1944 {
1945 case SIGFPE:
1946 exception = &constraint_error;
1947 msg = "SIGFPE";
1948 break;
1949 case SIGILL:
1950 exception = &constraint_error;
1951 msg = "SIGILL";
1952 break;
1953 case SIGSEGV:
1954 exception = &storage_error;
1955 msg = "stack overflow or erroneous memory access";
1956 break;
1957 case SIGBUS:
1958 exception = &constraint_error;
1959 msg = "SIGBUS";
1960 break;
1961 default:
1962 exception = &program_error;
1963 msg = "unhandled signal";
1964 }
1965
1966 Raise_From_Signal_Handler(exception, msg);
1967 }
1968
1969 void
1970 __gnat_install_handler(void)
1971 {
1972 struct sigaction act;
1973
1974 act.sa_handler = __gnat_error_handler;
1975 act.sa_flags = SA_NODEFER | SA_RESTART;
1976 sigemptyset (&act.sa_mask);
1977
1978 /* Do not install handlers if interrupt state is "System". */
1979 if (__gnat_get_interrupt_state (SIGFPE) != 's')
1980 sigaction (SIGFPE, &act, NULL);
1981 if (__gnat_get_interrupt_state (SIGILL) != 's')
1982 sigaction (SIGILL, &act, NULL);
1983 if (__gnat_get_interrupt_state (SIGSEGV) != 's')
1984 sigaction (SIGSEGV, &act, NULL);
1985 if (__gnat_get_interrupt_state (SIGBUS) != 's')
1986 sigaction (SIGBUS, &act, NULL);
1987
1988 __gnat_handler_installed = 1;
1989 }
1990
1991 /*******************/
1992 /* OpenBSD Section */
1993 /*******************/
1994
1995 #elif defined(__OpenBSD__)
1996
1997 #include <signal.h>
1998 #include <unistd.h>
1999
2000 static void
2001 __gnat_error_handler (int sig)
2002 {
2003 struct Exception_Data *exception;
2004 const char *msg;
2005
2006 switch(sig)
2007 {
2008 case SIGFPE:
2009 exception = &constraint_error;
2010 msg = "SIGFPE";
2011 break;
2012 case SIGILL:
2013 exception = &constraint_error;
2014 msg = "SIGILL";
2015 break;
2016 case SIGSEGV:
2017 exception = &storage_error;
2018 msg = "stack overflow or erroneous memory access";
2019 break;
2020 case SIGBUS:
2021 exception = &constraint_error;
2022 msg = "SIGBUS";
2023 break;
2024 default:
2025 exception = &program_error;
2026 msg = "unhandled signal";
2027 }
2028
2029 Raise_From_Signal_Handler(exception, msg);
2030 }
2031
2032 void
2033 __gnat_install_handler(void)
2034 {
2035 struct sigaction act;
2036
2037 act.sa_handler = __gnat_error_handler;
2038 act.sa_flags = SA_NODEFER | SA_RESTART;
2039 sigemptyset (&act.sa_mask);
2040
2041 /* Do not install handlers if interrupt state is "System" */
2042 if (__gnat_get_interrupt_state (SIGFPE) != 's')
2043 sigaction (SIGFPE, &act, NULL);
2044 if (__gnat_get_interrupt_state (SIGILL) != 's')
2045 sigaction (SIGILL, &act, NULL);
2046 if (__gnat_get_interrupt_state (SIGSEGV) != 's')
2047 sigaction (SIGSEGV, &act, NULL);
2048 if (__gnat_get_interrupt_state (SIGBUS) != 's')
2049 sigaction (SIGBUS, &act, NULL);
2050
2051 __gnat_handler_installed = 1;
2052 }
2053
2054 /******************/
2055 /* Darwin Section */
2056 /******************/
2057
2058 #elif defined(__APPLE__)
2059
2060 #include <signal.h>
2061 #include <sys/syscall.h>
2062 #include <mach/mach_vm.h>
2063 #include <mach/mach_init.h>
2064 #include <mach/vm_statistics.h>
2065
2066 /* This must be in keeping with System.OS_Interface.Alternate_Stack_Size. */
2067 char __gnat_alternate_stack[32 * 1024]; /* 1 * MINSIGSTKSZ */
2068
2069 /* Defined in xnu unix_signal.c.
2070 Tell the kernel to re-use alt stack when delivering a signal. */
2071 #define UC_RESET_ALT_STACK 0x80000000
2072
2073 /* Return true if ADDR is within a stack guard area. */
2074 static int
2075 __gnat_is_stack_guard (mach_vm_address_t addr)
2076 {
2077 kern_return_t kret;
2078 vm_region_submap_info_data_64_t info;
2079 mach_vm_address_t start;
2080 mach_vm_size_t size;
2081 natural_t depth;
2082 mach_msg_type_number_t count;
2083
2084 count = VM_REGION_SUBMAP_INFO_COUNT_64;
2085 start = addr;
2086 size = -1;
2087 depth = 9999;
2088 kret = mach_vm_region_recurse (mach_task_self (), &start, &size, &depth,
2089 (vm_region_recurse_info_t) &info, &count);
2090 if (kret == KERN_SUCCESS
2091 && addr >= start && addr < (start + size)
2092 && info.protection == VM_PROT_NONE
2093 && info.user_tag == VM_MEMORY_STACK)
2094 return 1;
2095 return 0;
2096 }
2097
2098 #define HAVE_GNAT_ADJUST_CONTEXT_FOR_RAISE
2099
2100 void
2101 __gnat_adjust_context_for_raise (int signo ATTRIBUTE_UNUSED,
2102 void *ucontext ATTRIBUTE_UNUSED)
2103 {
2104 #if defined (__x86_64__)
2105 /* Work around radar #10302855/pr50678, where the unwinders (libunwind or
2106 libgcc_s depending on the system revision) and the DWARF unwind data for
2107 the sigtramp have different ideas about register numbering (causing rbx
2108 and rdx to be transposed).. */
2109 ucontext_t *uc = (ucontext_t *)ucontext ;
2110 unsigned long t = uc->uc_mcontext->__ss.__rbx;
2111
2112 uc->uc_mcontext->__ss.__rbx = uc->uc_mcontext->__ss.__rdx;
2113 uc->uc_mcontext->__ss.__rdx = t;
2114 #endif
2115 }
2116
2117 static void
2118 __gnat_error_handler (int sig, siginfo_t *si, void *ucontext)
2119 {
2120 struct Exception_Data *exception;
2121 const char *msg;
2122
2123 __gnat_adjust_context_for_raise (sig, ucontext);
2124
2125 switch (sig)
2126 {
2127 case SIGSEGV:
2128 case SIGBUS:
2129 if (__gnat_is_stack_guard ((unsigned long)si->si_addr))
2130 {
2131 exception = &storage_error;
2132 msg = "stack overflow";
2133 }
2134 else
2135 {
2136 exception = &constraint_error;
2137 msg = "erroneous memory access";
2138 }
2139 /* Reset the use of alt stack, so that the alt stack will be used
2140 for the next signal delivery.
2141 The stack can't be used in case of stack checking. */
2142 syscall (SYS_sigreturn, NULL, UC_RESET_ALT_STACK);
2143 break;
2144
2145 case SIGFPE:
2146 exception = &constraint_error;
2147 msg = "SIGFPE";
2148 break;
2149
2150 default:
2151 exception = &program_error;
2152 msg = "unhandled signal";
2153 }
2154
2155 Raise_From_Signal_Handler (exception, msg);
2156 }
2157
2158 void
2159 __gnat_install_handler (void)
2160 {
2161 struct sigaction act;
2162
2163 /* Set up signal handler to map synchronous signals to appropriate
2164 exceptions. Make sure that the handler isn't interrupted by another
2165 signal that might cause a scheduling event! Also setup an alternate
2166 stack region for the handler execution so that stack overflows can be
2167 handled properly, avoiding a SEGV generation from stack usage by the
2168 handler itself (and it is required by Darwin). */
2169
2170 stack_t stack;
2171 stack.ss_sp = __gnat_alternate_stack;
2172 stack.ss_size = sizeof (__gnat_alternate_stack);
2173 stack.ss_flags = 0;
2174 sigaltstack (&stack, NULL);
2175
2176 act.sa_flags = SA_NODEFER | SA_RESTART | SA_SIGINFO;
2177 act.sa_sigaction = __gnat_error_handler;
2178 sigemptyset (&act.sa_mask);
2179
2180 /* Do not install handlers if interrupt state is "System". */
2181 if (__gnat_get_interrupt_state (SIGABRT) != 's')
2182 sigaction (SIGABRT, &act, NULL);
2183 if (__gnat_get_interrupt_state (SIGFPE) != 's')
2184 sigaction (SIGFPE, &act, NULL);
2185 if (__gnat_get_interrupt_state (SIGILL) != 's')
2186 sigaction (SIGILL, &act, NULL);
2187
2188 act.sa_flags |= SA_ONSTACK;
2189 if (__gnat_get_interrupt_state (SIGSEGV) != 's')
2190 sigaction (SIGSEGV, &act, NULL);
2191 if (__gnat_get_interrupt_state (SIGBUS) != 's')
2192 sigaction (SIGBUS, &act, NULL);
2193
2194 __gnat_handler_installed = 1;
2195 }
2196
2197 #else
2198
2199 /* For all other versions of GNAT, the handler does nothing. */
2200
2201 /*******************/
2202 /* Default Section */
2203 /*******************/
2204
2205 void
2206 __gnat_install_handler (void)
2207 {
2208 __gnat_handler_installed = 1;
2209 }
2210
2211 #endif
2212
2213 /*********************/
2214 /* __gnat_init_float */
2215 /*********************/
2216
2217 /* This routine is called as each process thread is created, for possible
2218 initialization of the FP processor. This version is used under INTERIX
2219 and WIN32. */
2220
2221 #if defined (_WIN32) || defined (__INTERIX) \
2222 || defined (__Lynx__) || defined(__NetBSD__) || defined(__FreeBSD__) \
2223 || defined (__OpenBSD__)
2224
2225 #define HAVE_GNAT_INIT_FLOAT
2226
2227 void
2228 __gnat_init_float (void)
2229 {
2230 #if defined (__i386__) || defined (i386) || defined (__x86_64)
2231
2232 /* This is used to properly initialize the FPU on an x86 for each
2233 process thread. */
2234
2235 asm ("finit");
2236
2237 #endif /* Defined __i386__ */
2238 }
2239 #endif
2240
2241 #ifndef HAVE_GNAT_INIT_FLOAT
2242
2243 /* All targets without a specific __gnat_init_float will use an empty one. */
2244 void
2245 __gnat_init_float (void)
2246 {
2247 }
2248 #endif
2249
2250 /***********************************/
2251 /* __gnat_adjust_context_for_raise */
2252 /***********************************/
2253
2254 #ifndef HAVE_GNAT_ADJUST_CONTEXT_FOR_RAISE
2255
2256 /* All targets without a specific version will use an empty one. */
2257
2258 /* Given UCONTEXT a pointer to a context structure received by a signal
2259 handler for SIGNO, perform the necessary adjustments to let the handler
2260 raise an exception. Calls to this routine are not conditioned by the
2261 propagation scheme in use. */
2262
2263 void
2264 __gnat_adjust_context_for_raise (int signo ATTRIBUTE_UNUSED,
2265 void *ucontext ATTRIBUTE_UNUSED)
2266 {
2267 /* We used to compensate here for the raised from call vs raised from signal
2268 exception discrepancy with the GCC ZCX scheme, but this now can be dealt
2269 with generically in the unwinder (see GCC PR other/26208). This however
2270 requires the use of the _Unwind_GetIPInfo routine in raise-gcc.c, which
2271 is predicated on the definition of HAVE_GETIPINFO at compile time. Only
2272 the VMS ports still do the compensation described in the few lines below.
2273
2274 *** Call vs signal exception discrepancy with GCC ZCX scheme ***
2275
2276 The GCC unwinder expects to be dealing with call return addresses, since
2277 this is the "nominal" case of what we retrieve while unwinding a regular
2278 call chain.
2279
2280 To evaluate if a handler applies at some point identified by a return
2281 address, the propagation engine needs to determine what region the
2282 corresponding call instruction pertains to. Because the return address
2283 may not be attached to the same region as the call, the unwinder always
2284 subtracts "some" amount from a return address to search the region
2285 tables, amount chosen to ensure that the resulting address is inside the
2286 call instruction.
2287
2288 When we raise an exception from a signal handler, e.g. to transform a
2289 SIGSEGV into Storage_Error, things need to appear as if the signal
2290 handler had been "called" by the instruction which triggered the signal,
2291 so that exception handlers that apply there are considered. What the
2292 unwinder will retrieve as the return address from the signal handler is
2293 what it will find as the faulting instruction address in the signal
2294 context pushed by the kernel. Leaving this address untouched looses, if
2295 the triggering instruction happens to be the very first of a region, as
2296 the later adjustments performed by the unwinder would yield an address
2297 outside that region. We need to compensate for the unwinder adjustments
2298 at some point, and this is what this routine is expected to do.
2299
2300 signo is passed because on some targets for some signals the PC in
2301 context points to the instruction after the faulting one, in which case
2302 the unwinder adjustment is still desired. */
2303 }
2304
2305 #endif
2306
2307 #ifdef __cplusplus
2308 }
2309 #endif