source: release/1.3/source/lisp-kernel/x86-exceptions.c @ 11770

Last change on this file since 11770 was 11770, checked in by rme, 11 years ago

Merge r11741 from trunk.

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File size: 95.7 KB
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1/*
2   Copyright (C) 2005 Clozure Associates
3   This file is part of OpenMCL. 
4
5   OpenMCL is licensed under the terms of the Lisp Lesser GNU Public
6   License , known as the LLGPL and distributed with OpenMCL as the
7   file "LICENSE".  The LLGPL consists of a preamble and the LGPL,
8   which is distributed with OpenMCL as the file "LGPL".  Where these
9   conflict, the preamble takes precedence. 
10
11   OpenMCL is referenced in the preamble as the "LIBRARY."
12
13   The LLGPL is also available online at
14   http://opensource.franz.com/preamble.html
15*/
16
17#include "lisp.h"
18#include "lisp-exceptions.h"
19#include "lisp_globals.h"
20#include "Threads.h"
21#include <ctype.h>
22#include <stdio.h>
23#include <stddef.h>
24#include <string.h>
25#include <stdarg.h>
26#include <errno.h>
27#include <stdio.h>
28#ifdef LINUX
29#include <strings.h>
30#include <sys/mman.h>
31#include <fpu_control.h>
32#include <linux/prctl.h>
33#endif
34#ifdef DARWIN
35#include <sysexits.h>
36#endif
37#ifndef WINDOWS
38#include <sys/syslog.h>
39#endif
40#ifdef WINDOWS
41#include <windows.h>
42#ifdef WIN_64
43#include <winternl.h>
44#include <ntstatus.h>
45#endif
46#ifndef EXCEPTION_WRITE_FAULT
47#define EXCEPTION_WRITE_FAULT 1
48#endif
49#endif
50
51int
52page_size = 4096;
53
54int
55log2_page_size = 12;
56
57
58void
59update_bytes_allocated(TCR* tcr, void *cur_allocptr)
60{
61  BytePtr
62    last = (BytePtr) tcr->last_allocptr, 
63    current = (BytePtr) cur_allocptr;
64  if (last && (tcr->save_allocbase != ((void *)VOID_ALLOCPTR))) {
65    tcr->bytes_allocated += last-current;
66  }
67  tcr->last_allocptr = 0;
68}
69
70
71
72//  This doesn't GC; it returns true if it made enough room, false
73//  otherwise.
74//  If "extend" is true, it can try to extend the dynamic area to
75//  satisfy the request.
76
77
78Boolean
79new_heap_segment(ExceptionInformation *xp, natural need, Boolean extend, TCR *tcr)
80{
81  area *a;
82  natural newlimit, oldlimit;
83  natural log2_allocation_quantum = tcr->log2_allocation_quantum;
84
85  a  = active_dynamic_area;
86  oldlimit = (natural) a->active;
87  newlimit = (align_to_power_of_2(oldlimit, log2_allocation_quantum) +
88              align_to_power_of_2(need, log2_allocation_quantum));
89  if (newlimit > (natural) (a->high)) {
90    if (extend) {
91      signed_natural inhibit = (signed_natural)(lisp_global(GC_INHIBIT_COUNT));
92      natural extend_by = inhibit ? 0 : lisp_heap_gc_threshold;
93      do {
94        if (resize_dynamic_heap(a->active, (newlimit-oldlimit)+extend_by)) {
95          break;
96        }
97        extend_by = align_to_power_of_2(extend_by>>1,log2_allocation_quantum);
98        if (extend_by < 4<<20) {
99          return false;
100        }
101      } while (1);
102    } else {
103      return false;
104    }
105  }
106  a->active = (BytePtr) newlimit;
107  tcr->last_allocptr = (void *)newlimit;
108  tcr->save_allocptr = (void *)newlimit;
109  xpGPR(xp,Iallocptr) = (LispObj) newlimit;
110  tcr->save_allocbase = (void *) oldlimit;
111
112  return true;
113}
114
115Boolean
116allocate_object(ExceptionInformation *xp,
117                natural bytes_needed, 
118                signed_natural disp_from_allocptr,
119                TCR *tcr)
120{
121  area *a = active_dynamic_area;
122
123  /* Maybe do an EGC */
124  if (a->older && lisp_global(OLDEST_EPHEMERAL)) {
125    if (((a->active)-(a->low)) >= a->threshold) {
126      gc_from_xp(xp, 0L);
127    }
128  }
129
130  /* Life is pretty simple if we can simply grab a segment
131     without extending the heap.
132  */
133  if (new_heap_segment(xp, bytes_needed, false, tcr)) {
134    xpGPR(xp, Iallocptr) -= disp_from_allocptr;
135    tcr->save_allocptr = (void *) (xpGPR(xp, Iallocptr));
136    return true;
137  }
138 
139  /* It doesn't make sense to try a full GC if the object
140     we're trying to allocate is larger than everything
141     allocated so far.
142  */
143  if ((lisp_global(HEAP_END)-lisp_global(HEAP_START)) > bytes_needed) {
144    untenure_from_area(tenured_area); /* force a full GC */
145    gc_from_xp(xp, 0L);
146  }
147 
148  /* Try again, growing the heap if necessary */
149  if (new_heap_segment(xp, bytes_needed, true, tcr)) {
150    xpGPR(xp, Iallocptr) -= disp_from_allocptr;
151    tcr->save_allocptr = (void *) (xpGPR(xp, Iallocptr));
152    return true;
153  }
154 
155  return false;
156}
157
158natural gc_deferred = 0, full_gc_deferred = 0;
159
160signed_natural
161flash_freeze(TCR *tcr, signed_natural param)
162{
163  return 0;
164}
165
166
167Boolean
168handle_gc_trap(ExceptionInformation *xp, TCR *tcr)
169{
170  LispObj selector = xpGPR(xp,Iimm0);
171#ifdef X8664
172  LispObj arg = xpGPR(xp,Iimm1);
173#else
174  LispObj arg = xpMMXreg(xp,Imm0);
175#endif
176  area *a = active_dynamic_area;
177  Boolean egc_was_enabled = (a->older != NULL);
178 
179  natural gc_previously_deferred = gc_deferred;
180
181  switch (selector) {
182  case GC_TRAP_FUNCTION_EGC_CONTROL:
183    egc_control(arg != 0, a->active);
184    xpGPR(xp,Iarg_z) = lisp_nil + (egc_was_enabled ? t_offset : 0);
185    break;
186
187  case GC_TRAP_FUNCTION_CONFIGURE_EGC:
188#ifdef X8664
189    a->threshold = unbox_fixnum(xpGPR(xp, Iarg_x));
190#else
191    a->threshold = unbox_fixnum(xpGPR(xp, Itemp0));
192#endif
193    g1_area->threshold = unbox_fixnum(xpGPR(xp, Iarg_y));
194    g2_area->threshold = unbox_fixnum(xpGPR(xp, Iarg_z));
195    xpGPR(xp,Iarg_z) = lisp_nil+t_offset;
196    break;
197
198  case GC_TRAP_FUNCTION_SET_LISP_HEAP_THRESHOLD:
199    if (((signed_natural) arg) > 0) {
200      lisp_heap_gc_threshold = 
201        align_to_power_of_2((arg-1) +
202                            (heap_segment_size - 1),
203                            log2_heap_segment_size);
204    }
205    /* fall through */
206  case GC_TRAP_FUNCTION_GET_LISP_HEAP_THRESHOLD:
207    xpGPR(xp, Iimm0) = lisp_heap_gc_threshold;
208    break;
209
210  case GC_TRAP_FUNCTION_USE_LISP_HEAP_THRESHOLD:
211    /*  Try to put the current threshold in effect.  This may
212        need to disable/reenable the EGC. */
213    untenure_from_area(tenured_area);
214    resize_dynamic_heap(a->active,lisp_heap_gc_threshold);
215    if (egc_was_enabled) {
216      if ((a->high - a->active) >= a->threshold) {
217        tenure_to_area(tenured_area);
218      }
219    }
220    xpGPR(xp, Iimm0) = lisp_heap_gc_threshold;
221    break;
222
223  case GC_TRAP_FUNCTION_FLASH_FREEZE: /* Like freeze below, but no GC */
224    untenure_from_area(tenured_area);
225    gc_like_from_xp(xp,flash_freeze,0);
226    a->active = (BytePtr) align_to_power_of_2(a->active, log2_page_size);
227    tenured_area->static_dnodes = area_dnode(a->active, a->low);
228    if (egc_was_enabled) {
229      tenure_to_area(tenured_area);
230    }
231    xpGPR(xp, Iimm0) = tenured_area->static_dnodes << dnode_shift;
232    break;
233
234  default:
235    update_bytes_allocated(tcr, (void *) tcr->save_allocptr);
236
237    if (selector == GC_TRAP_FUNCTION_IMMEDIATE_GC) {
238      if (!full_gc_deferred) {
239        gc_from_xp(xp, 0L);
240        break;
241      }
242      /* Tried to do a full GC when gc was disabled.  That failed,
243         so try full GC now */
244      selector = GC_TRAP_FUNCTION_GC;
245    }
246   
247    if (egc_was_enabled) {
248      egc_control(false, (BytePtr) a->active);
249    }
250    gc_from_xp(xp, 0L);
251    if (gc_deferred > gc_previously_deferred) {
252      full_gc_deferred = 1;
253    } else {
254      full_gc_deferred = 0;
255    }
256    if (selector > GC_TRAP_FUNCTION_GC) {
257      if (selector & GC_TRAP_FUNCTION_IMPURIFY) {
258        impurify_from_xp(xp, 0L);
259        /*        nrs_GC_EVENT_STATUS_BITS.vcell |= gc_integrity_check_bit; */
260        gc_from_xp(xp, 0L);
261        release_readonly_area();
262      }
263      if (selector & GC_TRAP_FUNCTION_PURIFY) {
264        purify_from_xp(xp, 0L);
265        gc_from_xp(xp, 0L);
266      }
267      if (selector & GC_TRAP_FUNCTION_SAVE_APPLICATION) {
268        OSErr err;
269        extern OSErr save_application(unsigned, Boolean);
270        area *vsarea = tcr->vs_area;
271
272#ifdef WINDOWS 
273        arg = _open_osfhandle(arg,0);
274#endif
275        nrs_TOPLFUNC.vcell = *((LispObj *)(vsarea->high)-1);
276        err = save_application(arg, egc_was_enabled);
277        if (err == noErr) {
278          _exit(0);
279        }
280        fatal_oserr(": save_application", err);
281      }
282      switch (selector) {
283      case GC_TRAP_FUNCTION_SET_HONS_AREA_SIZE:
284        xpGPR(xp, Iimm0) = 0;
285        break;
286      case GC_TRAP_FUNCTION_FREEZE:
287        a->active = (BytePtr) align_to_power_of_2(a->active, log2_page_size);
288        tenured_area->static_dnodes = area_dnode(a->active, a->low);
289        xpGPR(xp, Iimm0) = tenured_area->static_dnodes << dnode_shift;
290        break;
291      default:
292        break;
293      }
294    }
295    if (egc_was_enabled) {
296      egc_control(true, NULL);
297    }
298    break;
299  }
300  return true;
301}
302
303 
304
305
306
307void
308push_on_lisp_stack(ExceptionInformation *xp, LispObj value)
309{
310  LispObj *vsp = (LispObj *)xpGPR(xp,Isp);
311  *--vsp = value;
312  xpGPR(xp,Isp) = (LispObj)vsp;
313}
314
315
316/* Hard to know if or whether this is necessary in general.  For now,
317   do it when we get a "wrong number of arguments" trap.
318*/
319void
320finish_function_entry(ExceptionInformation *xp)
321{
322#ifdef X8664
323  natural nargs = (xpGPR(xp,Inargs)&0xffff)>> fixnumshift;
324#else
325  natural nargs = xpGPR(xp,Inargs)>>fixnumshift;
326#endif
327  signed_natural disp;
328  LispObj *vsp =  (LispObj *) xpGPR(xp,Isp), ra = *vsp++;
329   
330  xpGPR(xp,Isp) = (LispObj) vsp;
331
332#ifdef X8664
333  disp = nargs - 3;
334#endif
335#ifdef X8632
336  disp = nargs - 2;
337#endif
338
339#ifdef X8664
340  if (disp > 0) {               /* implies that nargs > 3 */
341    vsp[disp] = xpGPR(xp,Irbp);
342    vsp[disp+1] = ra;
343    xpGPR(xp,Irbp) = (LispObj)(vsp+disp);
344    push_on_lisp_stack(xp,xpGPR(xp,Iarg_x));
345    push_on_lisp_stack(xp,xpGPR(xp,Iarg_y));
346    push_on_lisp_stack(xp,xpGPR(xp,Iarg_z));
347  } else {
348    push_on_lisp_stack(xp,ra);
349    push_on_lisp_stack(xp,xpGPR(xp,Irbp));
350    xpGPR(xp,Irbp) = xpGPR(xp,Isp);
351    if (nargs == 3) {
352      push_on_lisp_stack(xp,xpGPR(xp,Iarg_x));
353    }
354    if (nargs >= 2) {
355      push_on_lisp_stack(xp,xpGPR(xp,Iarg_y));
356    }
357    if (nargs >= 1) {
358      push_on_lisp_stack(xp,xpGPR(xp,Iarg_z));
359    }
360  }
361#endif
362#ifdef X8632
363  if (disp > 0) {               /* implies that nargs > 2 */
364    vsp[disp] = xpGPR(xp,Iebp);
365    vsp[disp+1] = ra;
366    xpGPR(xp,Iebp) = (LispObj)(vsp+disp);
367    xpGPR(xp,Isp) = (LispObj)vsp;
368    push_on_lisp_stack(xp,xpGPR(xp,Iarg_y));
369    push_on_lisp_stack(xp,xpGPR(xp,Iarg_z));
370  } else {
371    push_on_lisp_stack(xp,ra);
372    push_on_lisp_stack(xp,xpGPR(xp,Iebp));
373    xpGPR(xp,Iebp) = xpGPR(xp,Isp);
374    if (nargs == 2) {
375      push_on_lisp_stack(xp,xpGPR(xp,Iarg_y));
376    }
377    if (nargs >= 1) {
378      push_on_lisp_stack(xp,xpGPR(xp,Iarg_z));
379    }
380  }
381#endif
382}
383
384Boolean
385object_contains_pc(LispObj container, LispObj addr)
386{
387  if (fulltag_of(container) >= fulltag_misc) {
388    natural elements = header_element_count(header_of(container));
389    if ((addr >= container) &&
390        (addr < ((LispObj)&(deref(container,1+elements))))) {
391      return true;
392    }
393  }
394  return false;
395}
396
397LispObj
398create_exception_callback_frame(ExceptionInformation *xp, TCR *tcr)
399{
400  LispObj containing_uvector = 0, 
401    relative_pc, 
402    nominal_function = lisp_nil, 
403    f, tra, tra_f = 0, abs_pc;
404
405  f = xpGPR(xp,Ifn);
406  tra = *(LispObj*)(xpGPR(xp,Isp));
407
408#ifdef X8664
409  if (tag_of(tra) == tag_tra) {
410    if ((*((unsigned short *)tra) == RECOVER_FN_FROM_RIP_WORD0) &&
411        (*((unsigned char *)(tra+2)) == RECOVER_FN_FROM_RIP_BYTE2)) {
412      int sdisp = (*(int *) (tra+3));
413      tra_f = RECOVER_FN_FROM_RIP_LENGTH+tra+sdisp;
414    }
415    if (fulltag_of(tra_f) != fulltag_function) {
416      tra_f = 0;
417    }
418  } else {
419    tra = 0;
420  }
421#endif
422#ifdef X8632
423  if (fulltag_of(tra) == fulltag_tra) {
424    if (*(unsigned char *)tra == RECOVER_FN_OPCODE) {
425      tra_f = (LispObj)*(LispObj *)(tra + 1);
426    }
427    if (tra_f && header_subtag(header_of(tra_f)) != subtag_function) {
428      tra_f = 0;
429    }
430  } else {
431    tra = 0;
432  }
433#endif
434
435  abs_pc = (LispObj)xpPC(xp);
436
437#ifdef X8664
438  if (fulltag_of(f) == fulltag_function) 
439#else
440    if (fulltag_of(f) == fulltag_misc &&
441        header_subtag(header_of(f)) == subtag_function) 
442#endif
443      {
444        nominal_function = f;
445      } else {
446      if (tra_f) {
447        nominal_function = tra_f;
448      }
449    }
450 
451  f = xpGPR(xp,Ifn);
452  if (object_contains_pc(f, abs_pc)) {
453    containing_uvector = untag(f)+fulltag_misc;
454  } else {
455    f = xpGPR(xp,Ixfn);
456    if (object_contains_pc(f, abs_pc)) {
457      containing_uvector = untag(f)+fulltag_misc;
458    } else {
459      if (tra_f) {
460        f = tra_f;
461        if (object_contains_pc(f, abs_pc)) {
462          containing_uvector = untag(f)+fulltag_misc;
463          relative_pc = (abs_pc - f) << fixnumshift;
464        }
465      }
466    }
467  }
468  if (containing_uvector) {
469    relative_pc = (abs_pc - (LispObj)&(deref(containing_uvector,1))) << fixnumshift;
470  } else {
471    containing_uvector = lisp_nil;
472    relative_pc = abs_pc << fixnumshift;
473  }
474  push_on_lisp_stack(xp,(LispObj)(tcr->xframe->prev));
475  push_on_lisp_stack(xp,(LispObj)(tcr->foreign_sp));
476  push_on_lisp_stack(xp,tra);
477  push_on_lisp_stack(xp,(LispObj)xp);
478  push_on_lisp_stack(xp,containing_uvector); 
479  push_on_lisp_stack(xp,relative_pc);
480  push_on_lisp_stack(xp,nominal_function);
481  push_on_lisp_stack(xp,0);
482#ifdef X8664
483  push_on_lisp_stack(xp,xpGPR(xp,Irbp));
484  xpGPR(xp,Irbp) = xpGPR(xp,Isp);
485#else
486  push_on_lisp_stack(xp,xpGPR(xp,Iebp));
487  xpGPR(xp,Iebp) = xpGPR(xp,Isp);
488#endif
489  return xpGPR(xp,Isp);
490}
491
492#ifndef XMEMFULL
493#define XMEMFULL (76)
494#endif
495
496void
497lisp_allocation_failure(ExceptionInformation *xp, TCR *tcr, natural bytes_needed )
498{
499  LispObj xcf = create_exception_callback_frame(xp, tcr),
500    cmain = nrs_CMAIN.vcell;
501  int skip;
502   
503  tcr->save_allocptr = tcr->save_allocbase = (void *)VOID_ALLOCPTR;
504  xpGPR(xp,Iallocptr) = VOID_ALLOCPTR;
505
506  skip = callback_to_lisp(tcr, cmain, xp, xcf, -1, XMEMFULL, 0, 0);
507  xpPC(xp) += skip;
508}
509
510/*
511  Allocate a large list, where "large" means "large enough to
512  possibly trigger the EGC several times if this was done
513  by individually allocating each CONS."  The number of
514  ocnses in question is in arg_z; on successful return,
515  the list will be in arg_z
516*/
517
518Boolean
519allocate_list(ExceptionInformation *xp, TCR *tcr)
520{
521  natural
522    nconses = (unbox_fixnum(xpGPR(xp,Iarg_z))),
523    bytes_needed = (nconses << dnode_shift);
524  LispObj
525    prev = lisp_nil,
526    current,
527    initial = xpGPR(xp,Iarg_y);
528
529  if (nconses == 0) {
530    /* Silly case */
531    xpGPR(xp,Iarg_z) = lisp_nil;
532    xpGPR(xp,Iallocptr) = lisp_nil;
533    return true;
534  }
535  update_bytes_allocated(tcr, (void *)(void *) tcr->save_allocptr);
536  if (allocate_object(xp,bytes_needed,bytes_needed-fulltag_cons,tcr)) {
537    tcr->save_allocptr -= fulltag_cons;
538    for (current = xpGPR(xp,Iallocptr);
539         nconses;
540         prev = current, current+= dnode_size, nconses--) {
541      deref(current,0) = prev;
542      deref(current,1) = initial;
543    }
544    xpGPR(xp,Iarg_z) = prev;
545  } else {
546    lisp_allocation_failure(xp,tcr,bytes_needed);
547  }
548  return true;
549}
550
551Boolean
552handle_alloc_trap(ExceptionInformation *xp, TCR *tcr)
553{
554  natural cur_allocptr, bytes_needed;
555  unsigned allocptr_tag;
556  signed_natural disp;
557 
558  cur_allocptr = xpGPR(xp,Iallocptr);
559  allocptr_tag = fulltag_of(cur_allocptr);
560  if (allocptr_tag == fulltag_misc) {
561#ifdef X8664
562    disp = xpGPR(xp,Iimm1);
563#else
564    disp = xpGPR(xp,Iimm0);
565#endif
566  } else {
567    disp = dnode_size-fulltag_cons;
568  }
569  bytes_needed = disp+allocptr_tag;
570
571  update_bytes_allocated(tcr,((BytePtr)(cur_allocptr+disp)));
572  if (allocate_object(xp, bytes_needed, disp, tcr)) {
573    return true;
574  }
575 
576  lisp_allocation_failure(xp,tcr,bytes_needed);
577
578  return true;
579}
580
581 
582int
583callback_to_lisp (TCR * tcr, LispObj callback_macptr, ExceptionInformation *xp,
584                  natural arg1, natural arg2, natural arg3, natural arg4, natural arg5)
585{
586  natural  callback_ptr;
587  int delta;
588  unsigned old_mxcsr = get_mxcsr();
589#ifdef X8632
590  natural saved_node_regs_mask = tcr->node_regs_mask;
591  LispObj *vsp = (LispObj *)xpGPR(xp, Isp);
592#endif
593
594  set_mxcsr(0x1f80);
595
596  /* Put the active stack pointers where .SPcallback expects them */
597#ifdef X8664
598  tcr->save_vsp = (LispObj *) xpGPR(xp, Isp);
599  tcr->save_rbp = (LispObj *) xpGPR(xp, Irbp);
600#else
601  tcr->node_regs_mask = X8632_DEFAULT_NODE_REGS_MASK;
602
603  *--vsp = tcr->save0;
604  *--vsp = tcr->save1;
605  *--vsp = tcr->save2;
606  *--vsp = tcr->save3;
607  *--vsp = tcr->next_method_context;
608  xpGPR(xp, Isp) = (LispObj)vsp;
609
610  tcr->save_vsp = (LispObj *)xpGPR(xp, Isp);
611  tcr->save_ebp = (LispObj *)xpGPR(xp, Iebp);
612#endif
613
614  /* Call back.  The caller of this function may have modified stack/frame
615     pointers (and at least should have called prepare_for_callback()).
616  */
617  callback_ptr = ((macptr *)ptr_from_lispobj(untag(callback_macptr)))->address;
618  UNLOCK(lisp_global(EXCEPTION_LOCK), tcr);
619  delta = ((int (*)())callback_ptr) (xp, arg1, arg2, arg3, arg4, arg5);
620  LOCK(lisp_global(EXCEPTION_LOCK), tcr);
621
622#ifdef X8632
623  tcr->next_method_context = *vsp++;
624  tcr->save3 = *vsp++;
625  tcr->save2 = *vsp++;
626  tcr->save1 = *vsp++;
627  tcr->save0 = *vsp++;
628  xpGPR(xp, Isp) = (LispObj)vsp;
629
630  tcr->node_regs_mask = saved_node_regs_mask;
631#endif
632  set_mxcsr(old_mxcsr);
633  return delta;
634}
635
636void
637callback_for_interrupt(TCR *tcr, ExceptionInformation *xp)
638{
639  LispObj *save_vsp = (LispObj *)xpGPR(xp,Isp),
640    word_beyond_vsp = save_vsp[-1],
641#ifdef X8664
642    save_rbp = xpGPR(xp,Irbp),
643#else
644    save_ebp = xpGPR(xp,Iebp),
645#endif
646    xcf = create_exception_callback_frame(xp, tcr);
647  int save_errno = errno;
648
649  callback_to_lisp(tcr, nrs_CMAIN.vcell,xp, xcf, 0, 0, 0, 0);
650#ifdef X8664
651  xpGPR(xp,Irbp) = save_rbp;
652#else
653  xpGPR(xp,Iebp) = save_ebp;
654#endif
655  xpGPR(xp,Isp) = (LispObj)save_vsp;
656  save_vsp[-1] = word_beyond_vsp;
657  errno = save_errno;
658}
659
660Boolean
661handle_error(TCR *tcr, ExceptionInformation *xp)
662{
663  pc program_counter = (pc)xpPC(xp);
664  unsigned char op0 = program_counter[0], op1 = program_counter[1];
665  LispObj rpc, errdisp = nrs_ERRDISP.vcell,
666    save_vsp = xpGPR(xp,Isp), xcf0;
667#ifdef X8664
668  LispObj save_rbp = xpGPR(xp,Irbp);
669#else
670  LispObj save_ebp = xpGPR(xp,Iebp);
671#endif
672  int skip;
673
674  if ((fulltag_of(errdisp) == fulltag_misc) &&
675      (header_subtag(header_of(errdisp)) == subtag_macptr)) {
676
677    if ((op0 == 0xcd) && (op1 >= 0xc0) && (op1 <= 0xc2)) {
678      finish_function_entry(xp);
679    }
680    xcf0 = create_exception_callback_frame(xp, tcr);
681    skip = callback_to_lisp(tcr, errdisp, xp, xcf0, 0, 0, 0, 0);
682    if (skip == -1) {
683      xcf *xcf1 = (xcf *)xcf0;
684      LispObj container = xcf1->containing_uvector;
685     
686      rpc = xcf1->relative_pc >> fixnumshift;
687      if (container == lisp_nil) {
688        xpPC(xp) = rpc;
689      } else {
690        xpPC(xp) = (LispObj)(&(deref(container,
691#ifdef X8664
692                                     1
693#else
694                                     0
695#endif
696)))+rpc;
697      }
698       
699      skip = 0;
700    }
701#ifdef X8664
702    xpGPR(xp,Irbp) = save_rbp;
703#else
704    xpGPR(xp,Iebp) = save_ebp;
705#endif
706    xpGPR(xp,Isp) = save_vsp;
707    if ((op0 == 0xcd) && (op1 == 0xc7)) {
708      /* Continue after an undefined function call. The function
709         that had been undefined has already been called (in the
710         break loop), and a list of the values that it returned
711         in in the xp's %arg_z.  A function that returns those
712         values in in the xp's %fn; we just have to adjust the
713         stack (keeping the return address in the right place
714         and discarding any stack args/reserved stack frame),
715         then set nargs and the PC so that that function's
716         called when we resume.
717      */
718      LispObj *vsp =(LispObj *)save_vsp, ra = *vsp;
719#ifdef X8664
720      int nargs = (xpGPR(xp, Inargs) & 0xffff)>>fixnumshift;
721#else
722      int nargs = xpGPR(xp, Inargs)>>fixnumshift;
723#endif
724
725#ifdef X8664
726      if (nargs > 3) {
727        xpGPR(xp,Isp)=(LispObj) (vsp + (1 + 2 + (nargs - 3)));
728        push_on_lisp_stack(xp,ra);
729      }
730#else
731      if (nargs > 2) {
732        xpGPR(xp,Isp)=(LispObj) (vsp + (1 + 2 + (nargs - 2)));
733        push_on_lisp_stack(xp,ra);
734      }
735#endif
736      xpPC(xp) = xpGPR(xp,Ifn);
737      xpGPR(xp,Inargs) = 1<<fixnumshift;
738    } else {
739      xpPC(xp) += skip;
740    }
741    return true;
742  } else {
743    return false;
744  }
745}
746
747
748protection_handler
749* protection_handlers[] = {
750  do_spurious_wp_fault,
751  do_soft_stack_overflow,
752  do_soft_stack_overflow,
753  do_soft_stack_overflow,
754  do_hard_stack_overflow,   
755  do_hard_stack_overflow,
756  do_hard_stack_overflow,
757};
758
759
760/* Maybe this'll work someday.  We may have to do something to
761   make the thread look like it's not handling an exception */
762void
763reset_lisp_process(ExceptionInformation *xp)
764{
765}
766
767Boolean
768do_hard_stack_overflow(ExceptionInformation *xp, protected_area_ptr area, BytePtr addr)
769{
770  reset_lisp_process(xp);
771  return false;
772}
773
774
775Boolean
776do_spurious_wp_fault(ExceptionInformation *xp, protected_area_ptr area, BytePtr addr)
777{
778
779  return false;
780}
781
782Boolean
783do_soft_stack_overflow(ExceptionInformation *xp, protected_area_ptr prot_area, BytePtr addr)
784{
785  /* Trying to write into a guard page on the vstack or tstack.
786     Allocate a new stack segment, emulate stwu and stwux for the TSP, and
787     signal an error_stack_overflow condition.
788      */
789  lisp_protection_kind which = prot_area->why;
790  Boolean on_TSP = (which == kTSPsoftguard);
791#ifdef X8664
792  LispObj save_rbp = xpGPR(xp,Irbp);
793#else
794  LispObj save_ebp = xpGPR(xp,Iebp);
795#endif
796  LispObj save_vsp = xpGPR(xp,Isp), 
797    xcf,
798    cmain = nrs_CMAIN.vcell;
799  area *a;
800  protected_area_ptr soft;
801  TCR *tcr = get_tcr(false);
802  int skip;
803
804  if ((fulltag_of(cmain) == fulltag_misc) &&
805      (header_subtag(header_of(cmain)) == subtag_macptr)) {
806    if (on_TSP) {
807      a = tcr->ts_area;
808    } else {
809      a = tcr->vs_area;
810    }
811    soft = a->softprot;
812    unprotect_area(soft);
813    xcf = create_exception_callback_frame(xp, tcr);
814    skip = callback_to_lisp(tcr, nrs_CMAIN.vcell, xp, xcf, SIGSEGV, on_TSP, 0, 0);
815#ifdef X8664
816    xpGPR(xp,Irbp) = save_rbp;
817#else
818    xpGPR(xp,Iebp) = save_ebp;
819#endif
820    xpGPR(xp,Isp) = save_vsp;
821    xpPC(xp) += skip;
822    return true;
823  }
824  return false;
825}
826
827Boolean
828is_write_fault(ExceptionInformation *xp, siginfo_t *info)
829{
830#ifdef DARWIN
831#ifdef X8664
832  return (UC_MCONTEXT(xp)->__es.__err & 0x2) != 0;
833#else
834  return (xp->uc_mcontext->__es.__err & 0x2) != 0;
835#endif
836#endif
837#if defined(LINUX) || defined(SOLARIS)
838  return (xpGPR(xp,REG_ERR) & 0x2) != 0;
839#endif
840#ifdef FREEBSD
841  return (xp->uc_mcontext.mc_err & 0x2) != 0;
842#endif
843#ifdef WINDOWS
844  return (info->ExceptionFlags == EXCEPTION_WRITE_FAULT);
845#endif
846}
847
848Boolean
849handle_fault(TCR *tcr, ExceptionInformation *xp, siginfo_t *info, int old_valence)
850{
851#ifdef FREEBSD
852#ifdef X8664
853  BytePtr addr = (BytePtr) xp->uc_mcontext.mc_addr;
854#else
855  BytePtr addr = (BytePtr) info->si_addr;
856#endif
857#else
858#ifdef WINDOWS
859  BytePtr addr = (BytePtr) info->ExceptionInformation[1];
860#else
861  BytePtr addr = (BytePtr) info->si_addr;
862#endif
863#endif
864
865
866  if (addr && (addr == tcr->safe_ref_address)) {
867    xpGPR(xp,Iimm0) = 0;
868    xpPC(xp) = xpGPR(xp,Ira0);
869    return true;
870  } else {
871    protected_area *a = find_protected_area(addr);
872    protection_handler *handler;
873
874    if (a) {
875      handler = protection_handlers[a->why];
876      return handler(xp, a, addr);
877    } else {
878      if ((addr >= readonly_area->low) &&
879          (addr < readonly_area->active)) {
880        UnProtectMemory((LogicalAddress)(truncate_to_power_of_2(addr,log2_page_size)),
881                        page_size);
882        return true;
883      }
884    }
885  }
886  if (old_valence == TCR_STATE_LISP) {
887    LispObj cmain = nrs_CMAIN.vcell,
888      xcf;
889    if ((fulltag_of(cmain) == fulltag_misc) &&
890      (header_subtag(header_of(cmain)) == subtag_macptr)) {
891      xcf = create_exception_callback_frame(xp, tcr);
892      callback_to_lisp(tcr, cmain, xp, xcf, SIGBUS, is_write_fault(xp,info), (natural)addr, 0);
893    }
894  }
895  return false;
896}
897
898Boolean
899handle_floating_point_exception(TCR *tcr, ExceptionInformation *xp, siginfo_t *info)
900{
901  int code,skip;
902  LispObj  xcf, cmain = nrs_CMAIN.vcell,
903    save_vsp = xpGPR(xp,Isp);
904#ifdef X8664
905  LispObj save_rbp = xpGPR(xp,Irbp);
906#else
907  LispObj save_ebp = xpGPR(xp,Iebp);
908#endif
909#ifdef WINDOWS
910  code = info->ExceptionCode;
911#else
912  code = info->si_code;
913#endif 
914
915  if ((fulltag_of(cmain) == fulltag_misc) &&
916      (header_subtag(header_of(cmain)) == subtag_macptr)) {
917    xcf = create_exception_callback_frame(xp, tcr);
918    skip = callback_to_lisp(tcr, cmain, xp, xcf, SIGFPE, code, 0, 0);
919    xpPC(xp) += skip;
920#ifdef X8664
921    xpGPR(xp,Irbp) = save_rbp;
922#else
923    xpGPR(xp,Iebp) = save_ebp;
924#endif
925    xpGPR(xp,Isp) = save_vsp;
926    return true;
927  } else {
928    return false;
929  }
930}
931
932
933Boolean
934extend_tcr_tlb(TCR *tcr, ExceptionInformation *xp)
935{
936  LispObj index, old_limit = tcr->tlb_limit, new_limit, new_bytes;
937  LispObj *old_tlb = tcr->tlb_pointer, *new_tlb, *work, *tos;
938
939  tos = (LispObj*)(xpGPR(xp,Isp));
940  index = *tos++;
941  (xpGPR(xp,Isp))=(LispObj)tos;
942 
943  new_limit = align_to_power_of_2(index+1,12);
944  new_bytes = new_limit-old_limit;
945  new_tlb = realloc(old_tlb, new_limit);
946
947  if (new_tlb == NULL) {
948    return false;
949  }
950  work = (LispObj *) ((BytePtr)new_tlb+old_limit);
951
952  while (new_bytes) {
953    *work++ = no_thread_local_binding_marker;
954    new_bytes -= sizeof(LispObj);
955  }
956  tcr->tlb_pointer = new_tlb;
957  tcr->tlb_limit = new_limit;
958  return true;
959}
960
961
962#if defined(FREEBSD) || defined(DARWIN)
963static
964char mxcsr_bit_to_fpe_code[] = {
965  FPE_FLTINV,                   /* ie */
966  0,                            /* de */
967  FPE_FLTDIV,                   /* ze */
968  FPE_FLTOVF,                   /* oe */
969  FPE_FLTUND,                   /* ue */
970  FPE_FLTRES                    /* pe */
971};
972
973void
974decode_vector_fp_exception(siginfo_t *info, uint32_t mxcsr)
975{
976  /* If the exception appears to be an XMM FP exception, try to
977     determine what it was by looking at bits in the mxcsr.
978  */
979  int xbit, maskbit;
980 
981  for (xbit = 0, maskbit = MXCSR_IM_BIT; xbit < 6; xbit++, maskbit++) {
982    if ((mxcsr & (1 << xbit)) &&
983        !(mxcsr & (1 << maskbit))) {
984      info->si_code = mxcsr_bit_to_fpe_code[xbit];
985      return;
986    }
987  }
988}
989
990#ifdef FREEBSD
991void
992freebsd_decode_vector_fp_exception(siginfo_t *info, ExceptionInformation *xp)
993{
994  if (info->si_code == 0) {
995#ifdef X8664
996    struct savefpu *fpu = (struct savefpu *) &(xp->uc_mcontext.mc_fpstate);
997#else
998    struct ccl_savexmm *fpu = (struct ccl_savexmm *) &(xp->uc_mcontext.mc_fpstate);
999#endif
1000    uint32_t mxcsr = fpu->sv_env.en_mxcsr;
1001
1002    decode_vector_fp_exception(info, mxcsr);
1003  }
1004}
1005#endif
1006
1007#ifdef DARWIN
1008void
1009darwin_decode_vector_fp_exception(siginfo_t *info, ExceptionInformation *xp)
1010{
1011  if (info->si_code == EXC_I386_SSEEXTERR) {
1012    uint32_t mxcsr = UC_MCONTEXT(xp)->__fs.__fpu_mxcsr;
1013
1014    decode_vector_fp_exception(info, mxcsr);
1015  }
1016}
1017
1018#endif
1019
1020#endif
1021
1022void
1023get_lisp_string(LispObj lisp_string, char *c_string, natural max)
1024{
1025  lisp_char_code *src = (lisp_char_code *)  (ptr_from_lispobj(lisp_string + misc_data_offset));
1026  natural i, n = header_element_count(header_of(lisp_string));
1027
1028  if (n > max) {
1029    n = max;
1030  }
1031
1032  for (i = 0; i < n; i++) {
1033    c_string[i] = 0xff & (src[i]);
1034  }
1035  c_string[n] = 0;
1036}
1037
1038Boolean
1039handle_exception(int signum, siginfo_t *info, ExceptionInformation  *context, TCR *tcr, int old_valence)
1040{
1041  pc program_counter = (pc)xpPC(context);
1042
1043  switch (signum) {
1044  case SIGNUM_FOR_INTN_TRAP:
1045    if (IS_MAYBE_INT_TRAP(info,context)) {
1046      /* Something mapped to SIGSEGV/SIGBUS that has nothing to do with
1047         a memory fault.  On x86, an "int n" instruction that's
1048         not otherwise implemented causes a "protecton fault".  Of
1049         course that has nothing to do with accessing protected
1050         memory; of course, most Unices act as if it did.*/
1051      if ((program_counter != NULL) &&
1052          (*program_counter == INTN_OPCODE)) {
1053        program_counter++;
1054        switch (*program_counter) {
1055        case UUO_ALLOC_TRAP:
1056          if (handle_alloc_trap(context, tcr)) {
1057            xpPC(context) += 2; /* we might have GCed. */
1058            return true;
1059          }
1060          break;
1061        case UUO_GC_TRAP:
1062          if (handle_gc_trap(context, tcr)) {
1063            xpPC(context) += 2;
1064            return true;
1065          }
1066          break;
1067           
1068        case UUO_DEBUG_TRAP:
1069          xpPC(context) = (natural) (program_counter+1);
1070          lisp_Debugger(context, info, debug_entry_dbg, false, "Lisp Breakpoint");
1071          return true;
1072           
1073        case UUO_DEBUG_TRAP_WITH_STRING:
1074          xpPC(context) = (natural) (program_counter+1);
1075          {
1076            char msg[512];
1077
1078            get_lisp_string(xpGPR(context,Iarg_z),msg, sizeof(msg)-1);
1079            lisp_Debugger(context, info, debug_entry_dbg, false, msg);
1080          }
1081          return true;
1082         
1083        default:
1084          return handle_error(tcr, context);
1085        }
1086      } else {
1087        return false;
1088      }
1089
1090    } else {
1091      return handle_fault(tcr, context, info, old_valence);
1092    }
1093    break;
1094
1095  case SIGNAL_FOR_PROCESS_INTERRUPT:
1096    tcr->interrupt_pending = 0;
1097    callback_for_interrupt(tcr, context);
1098    return true;
1099    break;
1100
1101
1102  case SIGILL:
1103    if ((program_counter[0] == XUUO_OPCODE_0) &&
1104        (program_counter[1] == XUUO_OPCODE_1)) {
1105      TCR *target = (TCR *)xpGPR(context, Iarg_z);
1106
1107      switch (program_counter[2]) {
1108      case XUUO_TLB_TOO_SMALL:
1109        if (extend_tcr_tlb(tcr,context)) {
1110          xpPC(context)+=3;
1111          return true;
1112        }
1113        break;
1114       
1115      case XUUO_INTERRUPT_NOW:
1116        callback_for_interrupt(tcr,context);
1117        xpPC(context)+=3;
1118        return true;
1119
1120      case XUUO_SUSPEND_NOW:
1121        xpPC(context)+=3;
1122        return true;
1123
1124      case XUUO_INTERRUPT:
1125        raise_thread_interrupt(target);
1126        xpPC(context)+=3;
1127        return true;
1128
1129      case XUUO_SUSPEND:
1130        xpGPR(context,Iimm0) = (LispObj) lisp_suspend_tcr(target);
1131        xpPC(context)+=3;
1132        return true;
1133
1134      case XUUO_SUSPEND_ALL:
1135        lisp_suspend_other_threads();
1136        xpPC(context)+=3;
1137        return true;
1138
1139
1140      case XUUO_RESUME:
1141        xpGPR(context,Iimm0) = (LispObj) lisp_resume_tcr(target);
1142        xpPC(context)+=3;
1143        return true;
1144       
1145      case XUUO_RESUME_ALL:
1146        lisp_resume_other_threads();
1147        xpPC(context)+=3;
1148        return true;
1149       
1150      case XUUO_KILL:
1151        xpGPR(context,Iimm0) = (LispObj)kill_tcr(target);
1152        xpPC(context)+=3;
1153        return true;
1154
1155      case XUUO_ALLOCATE_LIST:
1156        allocate_list(context,tcr);
1157        xpPC(context)+=3;
1158        return true;
1159
1160      default:
1161        return false;
1162      }
1163    } else {
1164      return false;
1165    }
1166    break;
1167   
1168  case SIGFPE:
1169#ifdef FREEBSD
1170    /* As of 6.1, FreeBSD/AMD64 doesn't seem real comfortable
1171       with this newfangled XMM business (and therefore info->si_code
1172       is often 0 on an XMM FP exception.
1173       Try to figure out what really happened by decoding mxcsr
1174       bits.
1175    */
1176    freebsd_decode_vector_fp_exception(info,context);
1177#endif
1178#ifdef DARWIN
1179    /* Same general problem with Darwin as of 8.7.2 */
1180    darwin_decode_vector_fp_exception(info,context);
1181#endif
1182
1183    return handle_floating_point_exception(tcr, context, info);
1184
1185#if SIGBUS != SIGNUM_FOR_INTN_TRAP
1186  case SIGBUS:
1187    return handle_fault(tcr, context, info, old_valence);
1188#endif
1189   
1190#if SIGSEGV != SIGNUM_FOR_INTN_TRAP
1191  case SIGSEGV:
1192    return handle_fault(tcr, context, info, old_valence);
1193#endif   
1194   
1195  default:
1196    return false;
1197  }
1198}
1199
1200
1201/*
1202   Current thread has all signals masked.  Before unmasking them,
1203   make it appear that the current thread has been suspended.
1204   (This is to handle the case where another thread is trying
1205   to GC before this thread is able to seize the exception lock.)
1206*/
1207int
1208prepare_to_wait_for_exception_lock(TCR *tcr, ExceptionInformation *context)
1209{
1210  int old_valence = tcr->valence;
1211
1212  tcr->pending_exception_context = context;
1213  tcr->valence = TCR_STATE_EXCEPTION_WAIT;
1214
1215#ifdef WINDOWS
1216  if (tcr->flags & (1<<TCR_FLAG_BIT_PENDING_SUSPEND)) {
1217    CLR_TCR_FLAG(tcr, TCR_FLAG_BIT_PENDING_SUSPEND);
1218    SEM_RAISE(tcr->suspend);
1219    SEM_WAIT_FOREVER(tcr->resume);
1220  }
1221#else
1222  ALLOW_EXCEPTIONS(context);
1223#endif
1224  return old_valence;
1225} 
1226
1227void
1228wait_for_exception_lock_in_handler(TCR *tcr, 
1229                                   ExceptionInformation *context,
1230                                   xframe_list *xf)
1231{
1232
1233  LOCK(lisp_global(EXCEPTION_LOCK), tcr);
1234#if 0
1235  fprintf(dbgout, "0x" LISP " has exception lock\n", tcr);
1236#endif
1237  xf->curr = context;
1238#ifdef X8632
1239  xf->node_regs_mask = tcr->node_regs_mask;
1240#endif
1241  xf->prev = tcr->xframe;
1242  tcr->xframe =  xf;
1243  tcr->pending_exception_context = NULL;
1244  tcr->valence = TCR_STATE_FOREIGN; 
1245}
1246
1247void
1248unlock_exception_lock_in_handler(TCR *tcr)
1249{
1250  tcr->pending_exception_context = tcr->xframe->curr;
1251#ifdef X8632
1252  tcr->node_regs_mask = tcr->xframe->node_regs_mask;
1253#endif
1254  tcr->xframe = tcr->xframe->prev;
1255  tcr->valence = TCR_STATE_EXCEPTION_RETURN;
1256  UNLOCK(lisp_global(EXCEPTION_LOCK),tcr);
1257#if 0
1258  fprintf(dbgout, "0x" LISP " released exception lock\n", tcr);
1259#endif
1260}
1261
1262/*
1263   If an interrupt is pending on exception exit, try to ensure
1264   that the thread sees it as soon as it's able to run.
1265*/
1266#ifdef WINDOWS
1267void
1268raise_pending_interrupt(TCR *tcr)
1269{
1270}
1271void
1272exit_signal_handler(TCR *tcr, int old_valence)
1273{
1274}
1275void
1276signal_handler(int signum, siginfo_t *info, ExceptionInformation  *context, TCR *tcr, int old_valence)
1277{
1278}
1279#else
1280void
1281raise_pending_interrupt(TCR *tcr)
1282{
1283  if ((TCR_INTERRUPT_LEVEL(tcr) >= 0) &&
1284      (tcr->interrupt_pending)) {
1285    pthread_kill((pthread_t)(tcr->osid), SIGNAL_FOR_PROCESS_INTERRUPT);
1286  }
1287}
1288
1289void
1290exit_signal_handler(TCR *tcr, int old_valence)
1291{
1292  sigset_t mask;
1293  sigfillset(&mask);
1294#ifdef FREEBSD
1295  sigdelset(&mask,SIGTRAP);
1296#endif
1297 
1298  pthread_sigmask(SIG_SETMASK,&mask, NULL);
1299  tcr->valence = old_valence;
1300  tcr->pending_exception_context = NULL;
1301}
1302
1303void
1304signal_handler(int signum, siginfo_t *info, ExceptionInformation  *context
1305#ifdef DARWIN
1306               , TCR *tcr, int old_valence
1307#endif
1308)
1309{
1310#ifdef DARWIN_GS_HACK
1311  Boolean gs_was_tcr = ensure_gs_pthread();
1312#endif
1313  xframe_list xframe_link;
1314#ifndef DARWIN
1315  TCR *tcr = get_tcr(false);
1316
1317  int old_valence = prepare_to_wait_for_exception_lock(tcr, context);
1318#endif
1319  if (tcr->flags & (1<<TCR_FLAG_BIT_PENDING_SUSPEND)) {
1320    CLR_TCR_FLAG(tcr, TCR_FLAG_BIT_PENDING_SUSPEND);
1321    pthread_kill(pthread_self(), thread_suspend_signal);
1322  }
1323  wait_for_exception_lock_in_handler(tcr,context, &xframe_link);
1324
1325
1326  if (! handle_exception(signum, info, context, tcr, old_valence)) {
1327    char msg[512];
1328    Boolean foreign = (old_valence != TCR_STATE_LISP);
1329
1330    snprintf(msg, sizeof(msg), "Unhandled exception %d at 0x" LISP ", context->regs at #x" LISP "", signum, xpPC(context), (natural)xpGPRvector(context));
1331   
1332    if (lisp_Debugger(context, info, signum,  foreign, msg)) {
1333      SET_TCR_FLAG(tcr,TCR_FLAG_BIT_PROPAGATE_EXCEPTION);
1334    }
1335  }
1336  unlock_exception_lock_in_handler(tcr);
1337#ifndef DARWIN_USE_PSEUDO_SIGRETURN
1338  exit_signal_handler(tcr, old_valence);
1339#endif
1340  /* raise_pending_interrupt(tcr); */
1341#ifdef DARWIN_GS_HACK
1342  if (gs_was_tcr) {
1343    set_gs_address(tcr);
1344  }
1345#endif
1346#ifndef DARWIN_USE_PSEUDO_SIGRETURN
1347  SIGRETURN(context);
1348#endif
1349}
1350#endif
1351
1352
1353
1354
1355#ifdef LINUX
1356/* type of pointer to saved fp state */
1357#ifdef X8664
1358typedef fpregset_t FPREGS;
1359#else
1360typedef struct _fpstate *FPREGS;
1361#endif
1362LispObj *
1363copy_fpregs(ExceptionInformation *xp, LispObj *current, FPREGS *destptr)
1364{
1365  FPREGS src = (FPREGS)(xp->uc_mcontext.fpregs), dest;
1366 
1367  if (src) {
1368    dest = ((FPREGS)current)-1;
1369    *dest = *src;
1370    *destptr = dest;
1371    current = (LispObj *) dest;
1372  }
1373  return current;
1374}
1375#endif
1376
1377#ifdef DARWIN
1378LispObj *
1379copy_darwin_mcontext(MCONTEXT_T context, 
1380                     LispObj *current, 
1381                     MCONTEXT_T *out)
1382{
1383  MCONTEXT_T dest = ((MCONTEXT_T)current)-1;
1384  dest = (MCONTEXT_T) (((LispObj)dest) & ~15);
1385
1386  *dest = *context;
1387  *out = dest;
1388  return (LispObj *)dest;
1389}
1390#endif
1391
1392LispObj *
1393copy_siginfo(siginfo_t *info, LispObj *current)
1394{
1395  siginfo_t *dest = ((siginfo_t *)current) - 1;
1396#if !defined(LINUX) || !defined(X8632)
1397  dest = (siginfo_t *) (((LispObj)dest)&~15);
1398#endif
1399  *dest = *info;
1400  return (LispObj *)dest;
1401}
1402
1403#ifdef LINUX
1404typedef FPREGS copy_ucontext_last_arg_t;
1405#else
1406typedef void * copy_ucontext_last_arg_t;
1407#endif
1408
1409#ifndef WINDOWS
1410LispObj *
1411copy_ucontext(ExceptionInformation *context, LispObj *current, copy_ucontext_last_arg_t fp)
1412{
1413  ExceptionInformation *dest = ((ExceptionInformation *)current)-1;
1414#if !defined(LINUX) || !defined(X8632)
1415  dest = (ExceptionInformation *) (((LispObj)dest) & ~15);
1416#endif
1417
1418  *dest = *context;
1419  /* Fix it up a little; where's the signal mask allocated, if indeed
1420     it is "allocated" ? */
1421#ifdef LINUX
1422  dest->uc_mcontext.fpregs = (fpregset_t)fp;
1423#endif
1424  dest->uc_stack.ss_sp = 0;
1425  dest->uc_stack.ss_size = 0;
1426  dest->uc_stack.ss_flags = 0;
1427  dest->uc_link = NULL;
1428  return (LispObj *)dest;
1429}
1430#endif
1431
1432
1433LispObj *
1434tcr_frame_ptr(TCR *tcr)
1435{
1436  ExceptionInformation *xp;
1437  LispObj *bp;
1438
1439  if (tcr->pending_exception_context)
1440    xp = tcr->pending_exception_context;
1441  else if (tcr->valence == TCR_STATE_LISP) {
1442    xp = tcr->suspend_context;
1443  } else {
1444    xp = NULL;
1445  }
1446  if (xp) {
1447#ifdef X8664
1448    bp = (LispObj *) xpGPR(xp, Irbp);
1449#else
1450    bp = (LispObj *) xpGPR(xp, Iebp);
1451#endif
1452  } else {
1453#ifdef X8664
1454    bp = tcr->save_rbp;
1455#else
1456    bp = tcr->save_ebp;
1457#endif
1458  }
1459  return bp;
1460}
1461
1462
1463LispObj *
1464find_foreign_rsp(LispObj rsp, area *foreign_area, TCR *tcr)
1465{
1466
1467  if (((BytePtr)rsp < foreign_area->low) ||
1468      ((BytePtr)rsp > foreign_area->high)) {
1469    rsp = (LispObj)(tcr->foreign_sp);
1470  }
1471  return (LispObj *) (((rsp-128) & ~15));
1472}
1473
1474#ifdef X8632
1475#ifdef LINUX
1476/* This is here for debugging.  On entry to a signal handler that
1477   receives info and context arguments, the stack should look exactly
1478   like this.  The "pretcode field" of the structure is the address
1479   of code that does an rt_sigreturn syscall, and rt_sigreturn expects
1480   %esp at the time of that syscall to be pointing just past the
1481   pretcode field.
1482   handle_signal_on_foreign_stack() and helpers have to be very
1483   careful to duplicate this "structure" exactly.
1484   Note that on x8664 Linux, rt_sigreturn expects a ucontext to
1485   be on top of the stack (with a siginfo_t underneath it.)
1486   It sort of half-works to do sigreturn via setcontext() on
1487   x8632 Linux, but (a) it may not be available on some distributions
1488   and (b) even a relatively modern version of it uses "fldenv" to
1489   restore FP context, and "fldenv" isn't nearly good enough.
1490*/
1491
1492struct rt_sigframe {
1493        char *pretcode;
1494        int sig;
1495        siginfo_t  *pinfo;
1496        void  *puc;
1497        siginfo_t info;
1498        struct ucontext uc;
1499        struct _fpstate fpstate;
1500        char retcode[8];
1501};
1502struct rt_sigframe *rtsf = 0;
1503
1504#endif
1505#endif
1506
1507
1508#ifndef WINDOWS
1509/* x8632 Linux requires that the stack-allocated siginfo is nearer
1510   the top of stack than the stack-allocated ucontext.  If other
1511   platforms care, they expect the ucontext to be nearer the top
1512   of stack.
1513*/
1514
1515#if defined(LINUX) && defined(X8632)
1516#define UCONTEXT_ON_TOP_OF_STACK 0
1517#else
1518#define UCONTEXT_ON_TOP_OF_STACK 1
1519#endif
1520void
1521handle_signal_on_foreign_stack(TCR *tcr,
1522                               void *handler, 
1523                               int signum, 
1524                               siginfo_t *info, 
1525                               ExceptionInformation *context,
1526                               LispObj return_address
1527#ifdef DARWIN_GS_HACK
1528                               , Boolean gs_was_tcr
1529#endif
1530                               )
1531{
1532#ifdef LINUX
1533  FPREGS fpregs = NULL;
1534#else
1535  void *fpregs = NULL;
1536#endif
1537#ifdef DARWIN
1538  MCONTEXT_T mcontextp = NULL;
1539#endif
1540  siginfo_t *info_copy = NULL;
1541  ExceptionInformation *xp = NULL;
1542  LispObj *foreign_rsp = find_foreign_rsp(xpGPR(context,Isp), tcr->cs_area, tcr);
1543
1544#ifdef LINUX
1545  foreign_rsp = copy_fpregs(context, foreign_rsp, &fpregs);
1546#endif
1547#ifdef DARWIN
1548  foreign_rsp = copy_darwin_mcontext(UC_MCONTEXT(context), foreign_rsp, &mcontextp);
1549#endif
1550#if UCONTEXT_ON_TOP_OF_STACK
1551  /* copy info first */
1552  foreign_rsp = copy_siginfo(info, foreign_rsp);
1553  info_copy = (siginfo_t *)foreign_rsp;
1554  foreign_rsp = copy_ucontext(context, foreign_rsp, fpregs);
1555  xp = (ExceptionInformation *)foreign_rsp;
1556#else
1557  foreign_rsp = copy_ucontext(context, foreign_rsp, fpregs);
1558  xp = (ExceptionInformation *)foreign_rsp;
1559  foreign_rsp = copy_siginfo(info, foreign_rsp);
1560  info_copy = (siginfo_t *)foreign_rsp;
1561#endif
1562#ifdef DARWIN
1563  UC_MCONTEXT(xp) = mcontextp;
1564#endif
1565  *--foreign_rsp = return_address;
1566#ifdef DARWIN_GS_HACK
1567  if (gs_was_tcr) {
1568    set_gs_address(tcr);
1569  }
1570#endif
1571  switch_to_foreign_stack(foreign_rsp,handler,signum,info_copy,xp);
1572}
1573#endif
1574
1575
1576#ifndef WINDOWS
1577#ifndef USE_SIGALTSTACK
1578void
1579arbstack_signal_handler(int signum, siginfo_t *info, ExceptionInformation *context)
1580{
1581  TCR *tcr = get_interrupt_tcr(false);
1582#if 1
1583  if (tcr->valence != TCR_STATE_LISP) {
1584    FBug(context, "exception in foreign context");
1585  }
1586#endif
1587  {
1588    area *vs = tcr->vs_area;
1589    BytePtr current_sp = (BytePtr) current_stack_pointer();
1590
1591
1592    if ((current_sp >= vs->low) &&
1593        (current_sp < vs->high)) {
1594      handle_signal_on_foreign_stack(tcr,
1595                                     signal_handler,
1596                                     signum,
1597                                     info,
1598                                     context,
1599                                     (LispObj)__builtin_return_address(0)
1600#ifdef DARWIN_GS_HACK
1601                                     , false
1602#endif
1603
1604                                     );
1605    } else {
1606      signal_handler(signum, info, context, tcr, 0);
1607    }
1608  }
1609}
1610
1611#else
1612void
1613altstack_signal_handler(int signum, siginfo_t *info, ExceptionInformation  *context)
1614{
1615  TCR* tcr = get_tcr(true);
1616#if 1
1617  if (tcr->valence != TCR_STATE_LISP) {
1618    FBug(context, "exception in foreign context");
1619  }
1620#endif
1621  handle_signal_on_foreign_stack(tcr,signal_handler,signum,info,context,(LispObj)__builtin_return_address(0)
1622#ifdef DARWIN_GS_HACK
1623                                 , false
1624#endif
1625);
1626}
1627#endif
1628#endif
1629
1630Boolean
1631stack_pointer_on_vstack_p(LispObj stack_pointer, TCR *tcr)
1632{
1633  area *a = tcr->vs_area;
1634 
1635  return (((BytePtr)stack_pointer <= a->high) &&
1636          ((BytePtr)stack_pointer > a->low));
1637}
1638
1639
1640#ifdef WINDOWS
1641extern DWORD restore_windows_context(ExceptionInformation *, TCR *, int);
1642#endif
1643
1644void
1645interrupt_handler (int signum, siginfo_t *info, ExceptionInformation *context)
1646{
1647#ifdef DARWIN_GS_HACK
1648  Boolean gs_was_tcr = ensure_gs_pthread();
1649#endif
1650  TCR *tcr = get_interrupt_tcr(false);
1651  int old_valence = tcr->valence;
1652
1653  if (tcr) {
1654    if ((TCR_INTERRUPT_LEVEL(tcr) < 0) ||
1655        (tcr->valence != TCR_STATE_LISP) ||
1656        (tcr->unwinding != 0) ||
1657        ! stack_pointer_on_vstack_p(xpGPR(context,Isp), tcr) ||
1658#ifdef X8664
1659        ! stack_pointer_on_vstack_p(xpGPR(context,Irbp), tcr)) {
1660#else
1661        ! stack_pointer_on_vstack_p(xpGPR(context,Iebp), tcr)) {
1662#endif
1663      tcr->interrupt_pending = (((natural) 1)<< (nbits_in_word - ((natural)1)));
1664    } else {
1665      LispObj cmain = nrs_CMAIN.vcell;
1666
1667      if ((fulltag_of(cmain) == fulltag_misc) &&
1668          (header_subtag(header_of(cmain)) == subtag_macptr)) {
1669        /*
1670           This thread can (allegedly) take an interrupt now.
1671        */
1672
1673        xframe_list xframe_link;
1674        signed_natural alloc_displacement = 0;
1675        LispObj
1676          *next_tsp = tcr->next_tsp,
1677          *save_tsp = tcr->save_tsp,
1678          *p,
1679          q;
1680        natural old_foreign_exception = tcr->flags & (1 << TCR_FLAG_BIT_FOREIGN_EXCEPTION);
1681
1682        tcr->flags &= ~(1 << TCR_FLAG_BIT_FOREIGN_EXCEPTION);
1683           
1684        if (next_tsp != save_tsp) {
1685          tcr->next_tsp = save_tsp;
1686        } else {
1687          next_tsp = NULL;
1688        }
1689        /* have to do this before allowing interrupts */
1690        pc_luser_xp(context, tcr, &alloc_displacement);
1691        old_valence = prepare_to_wait_for_exception_lock(tcr, context);
1692        wait_for_exception_lock_in_handler(tcr, context, &xframe_link);
1693        handle_exception(signum, info, context, tcr, old_valence);
1694        if (alloc_displacement) {
1695          tcr->save_allocptr -= alloc_displacement;
1696        }
1697        if (next_tsp) {
1698          tcr->next_tsp = next_tsp;
1699          p = next_tsp;
1700          while (p != save_tsp) {
1701            *p++ = 0;
1702          }
1703          q = (LispObj)save_tsp;
1704          *next_tsp = q;
1705        }
1706        tcr->flags |= old_foreign_exception;
1707        unlock_exception_lock_in_handler(tcr);
1708#ifndef WINDOWS
1709        exit_signal_handler(tcr, old_valence);
1710#endif
1711      }
1712    }
1713  }
1714#ifdef DARWIN_GS_HACK
1715  if (gs_was_tcr) {
1716    set_gs_address(tcr);
1717  }
1718#endif
1719#ifdef WINDOWS
1720  restore_windows_context(context,tcr,old_valence);
1721#else
1722  SIGRETURN(context);
1723#endif
1724}
1725
1726
1727#ifndef WINDOWS
1728#ifndef USE_SIGALTSTACK
1729void
1730arbstack_interrupt_handler (int signum, siginfo_t *info, ExceptionInformation *context)
1731{
1732#ifdef DARWIN_GS_HACK
1733  Boolean gs_was_tcr = ensure_gs_pthread();
1734#endif
1735  TCR *tcr = get_interrupt_tcr(false);
1736  area *vs = tcr->vs_area;
1737  BytePtr current_sp = (BytePtr) current_stack_pointer();
1738
1739  if ((current_sp >= vs->low) &&
1740      (current_sp < vs->high)) {
1741    handle_signal_on_foreign_stack(tcr,
1742                                   interrupt_handler,
1743                                   signum,
1744                                   info,
1745                                   context,
1746                                   (LispObj)__builtin_return_address(0)
1747#ifdef DARWIN_GS_HACK
1748                                   ,gs_was_tcr
1749#endif
1750                                   );
1751  } else {
1752    /* If we're not on the value stack, we pretty much have to be on
1753       the C stack.  Just run the handler. */
1754#ifdef DARWIN_GS_HACK
1755    if (gs_was_tcr) {
1756      set_gs_address(tcr);
1757    }
1758#endif
1759    interrupt_handler(signum, info, context);
1760  }
1761}
1762
1763#else /* altstack works */
1764 
1765void
1766altstack_interrupt_handler (int signum, siginfo_t *info, ExceptionInformation *context)
1767{
1768#ifdef DARWIN_GS_HACK
1769  Boolean gs_was_tcr = ensure_gs_pthread();
1770#endif
1771  TCR *tcr = get_interrupt_tcr(false);
1772  handle_signal_on_foreign_stack(tcr,interrupt_handler,signum,info,context,(LispObj)__builtin_return_address(0)
1773#ifdef DARWIN_GS_HACK
1774                                 ,gs_was_tcr
1775#endif
1776                                 );
1777}
1778
1779#endif
1780#endif
1781
1782#ifndef WINDOWS
1783void
1784install_signal_handler(int signo, void * handler)
1785{
1786  struct sigaction sa;
1787 
1788  sa.sa_sigaction = (void *)handler;
1789  sigfillset(&sa.sa_mask);
1790#ifdef FREEBSD
1791  /* Strange FreeBSD behavior wrt synchronous signals */
1792  sigdelset(&sa.sa_mask,SIGTRAP);  /* let GDB work */
1793#endif
1794  sa.sa_flags = 
1795    0 /* SA_RESTART */
1796#ifdef USE_SIGALTSTACK
1797    | SA_ONSTACK
1798#endif
1799    | SA_SIGINFO;
1800
1801  sigaction(signo, &sa, NULL);
1802}
1803#endif
1804
1805#ifdef WINDOWS
1806BOOL
1807CALLBACK ControlEventHandler(DWORD event)
1808{
1809  switch(event) {
1810  case CTRL_C_EVENT:
1811    lisp_global(INTFLAG) = (1 << fixnumshift);
1812    return TRUE;
1813    break;
1814  default:
1815    return FALSE;
1816  }
1817}
1818
1819int
1820map_windows_exception_code_to_posix_signal(DWORD code)
1821{
1822  switch (code) {
1823  case EXCEPTION_ACCESS_VIOLATION:
1824    return SIGSEGV;
1825  case EXCEPTION_FLT_DENORMAL_OPERAND:
1826  case EXCEPTION_FLT_DIVIDE_BY_ZERO:
1827  case EXCEPTION_FLT_INEXACT_RESULT:
1828  case EXCEPTION_FLT_INVALID_OPERATION:
1829  case EXCEPTION_FLT_OVERFLOW:
1830  case EXCEPTION_FLT_STACK_CHECK:
1831  case EXCEPTION_FLT_UNDERFLOW:
1832  case EXCEPTION_INT_DIVIDE_BY_ZERO:
1833  case EXCEPTION_INT_OVERFLOW:
1834    return SIGFPE;
1835  case EXCEPTION_PRIV_INSTRUCTION:
1836  case EXCEPTION_ILLEGAL_INSTRUCTION:
1837    return SIGILL;
1838  case EXCEPTION_IN_PAGE_ERROR:
1839    return SIGBUS;
1840  default:
1841    return -1;
1842  }
1843}
1844
1845
1846LONG
1847windows_exception_handler(EXCEPTION_POINTERS *exception_pointers, TCR *tcr)
1848{
1849  DWORD code = exception_pointers->ExceptionRecord->ExceptionCode;
1850  int old_valence, signal_number;
1851  ExceptionInformation *context = exception_pointers->ContextRecord;
1852  siginfo_t *info = exception_pointers->ExceptionRecord;
1853  xframe_list xframes;
1854
1855  old_valence = prepare_to_wait_for_exception_lock(tcr, context);
1856  wait_for_exception_lock_in_handler(tcr, context, &xframes);
1857
1858  signal_number = map_windows_exception_code_to_posix_signal(code);
1859 
1860  if (!handle_exception(signal_number, info, context, tcr, old_valence)) {
1861    char msg[512];
1862    Boolean foreign = (old_valence != TCR_STATE_LISP);
1863
1864    snprintf(msg, sizeof(msg), "Unhandled exception %d (windows code 0x%x) at 0x%Ix, context->regs at 0x%Ix", signal_number, code, xpPC(context), (natural)xpGPRvector(context));
1865   
1866    if (lisp_Debugger(context, info, signal_number,  foreign, msg)) {
1867      SET_TCR_FLAG(tcr,TCR_FLAG_BIT_PROPAGATE_EXCEPTION);
1868    }
1869  }
1870  unlock_exception_lock_in_handler(tcr);
1871  return restore_windows_context(context, tcr, old_valence);
1872}
1873
1874void
1875setup_exception_handler_call(CONTEXT *context,
1876                             LispObj new_sp,
1877                             void *handler,
1878                             EXCEPTION_POINTERS *new_ep,
1879                             TCR *tcr)
1880{
1881  extern void windows_halt(void);
1882  LispObj *p = (LispObj *)new_sp;
1883#ifdef WIN_64
1884  p-=4;                         /* win64 abi argsave nonsense */
1885  *(--p) = (LispObj)windows_halt;
1886  context->Rsp = (DWORD64)p;
1887  context->Rip = (DWORD64)handler;
1888  context->Rcx = (DWORD64)new_ep;
1889  context->Rdx = (DWORD64)tcr;
1890#else
1891  p-=4;                          /* args on stack, stack aligned */
1892  p[0] = (LispObj)new_ep;
1893  p[1] = (LispObj)tcr;
1894  *(--p) = (LispObj)windows_halt;
1895  context->Esp = (DWORD)p;
1896  context->Eip = (DWORD)handler;
1897#ifdef WIN32_ES_HACK
1898  context->SegEs = context->SegDs;
1899#endif
1900#endif
1901  context->EFlags &= ~0x400;  /* clear direction flag */
1902}
1903
1904void
1905prepare_to_handle_windows_exception_on_foreign_stack(TCR *tcr,
1906                                                     CONTEXT *context,
1907                                                     void *handler,
1908                                                     EXCEPTION_POINTERS *original_ep)
1909{
1910  LispObj foreign_rsp = 
1911    (LispObj) (tcr->foreign_sp - 128) & ~15;
1912  CONTEXT *new_context;
1913  siginfo_t *new_info;
1914  EXCEPTION_POINTERS *new_ep;
1915
1916  new_context = ((CONTEXT *)(foreign_rsp&~15))-1;
1917  *new_context = *context;
1918  foreign_rsp = (LispObj)new_context;
1919  new_info = ((siginfo_t *)(foreign_rsp&~15))-1;
1920  *new_info = *original_ep->ExceptionRecord;
1921  foreign_rsp = (LispObj)new_info;
1922  new_ep = ((EXCEPTION_POINTERS *)(foreign_rsp&~15))-1;
1923  foreign_rsp = (LispObj)new_ep & ~15;
1924  new_ep->ContextRecord = new_context;
1925  new_ep->ExceptionRecord = new_info;
1926  setup_exception_handler_call(context,foreign_rsp,handler,new_ep, tcr);
1927}
1928
1929LONG CALLBACK
1930windows_arbstack_exception_handler(EXCEPTION_POINTERS *exception_pointers)
1931{
1932  extern void ensure_safe_for_string_operations(void);
1933  DWORD code = exception_pointers->ExceptionRecord->ExceptionCode;
1934
1935
1936 
1937  if ((code & 0x80000000L) == 0) {
1938    return EXCEPTION_CONTINUE_SEARCH;
1939  } else {
1940    TCR *tcr = get_interrupt_tcr(false);
1941    area *cs = tcr->cs_area;
1942    BytePtr current_sp = (BytePtr) current_stack_pointer();
1943    CONTEXT *context = exception_pointers->ContextRecord;
1944   
1945    ensure_safe_for_string_operations();
1946
1947    if ((current_sp >= cs->low) &&
1948        (current_sp < cs->high)) {
1949      debug_show_registers(context, exception_pointers->ExceptionRecord, 0);
1950      FBug(context, "Exception on foreign stack\n");
1951      return EXCEPTION_CONTINUE_EXECUTION;
1952    }
1953
1954    prepare_to_handle_windows_exception_on_foreign_stack(tcr,
1955                                                         context,
1956                                                         windows_exception_handler,
1957                                                         exception_pointers);
1958    return EXCEPTION_CONTINUE_EXECUTION;
1959  }
1960}
1961
1962
1963void
1964install_pmcl_exception_handlers()
1965{
1966  AddVectoredExceptionHandler(1,windows_arbstack_exception_handler);
1967}
1968#else
1969void
1970install_pmcl_exception_handlers()
1971{
1972#ifndef DARWIN 
1973  void *handler = (void *)
1974#ifdef USE_SIGALTSTACK
1975    altstack_signal_handler
1976#else
1977    arbstack_signal_handler;
1978#endif
1979  ;
1980  install_signal_handler(SIGILL, handler);
1981 
1982  install_signal_handler(SIGBUS, handler);
1983  install_signal_handler(SIGSEGV,handler);
1984  install_signal_handler(SIGFPE, handler);
1985#endif
1986 
1987  install_signal_handler(SIGNAL_FOR_PROCESS_INTERRUPT,
1988#ifdef USE_SIGALTSTACK
1989                         altstack_interrupt_handler
1990#else
1991                         arbstack_interrupt_handler
1992#endif
1993);
1994  signal(SIGPIPE, SIG_IGN);
1995}
1996#endif
1997
1998#ifndef WINDOWS
1999#ifndef USE_SIGALTSTACK
2000void
2001arbstack_suspend_resume_handler(int signum, siginfo_t *info, ExceptionInformation  *context)
2002{
2003#ifdef DARWIN_GS_HACK
2004  Boolean gs_was_tcr = ensure_gs_pthread();
2005#endif
2006  TCR *tcr = get_interrupt_tcr(false);
2007  if (tcr != NULL) {
2008    area *vs = tcr->vs_area;
2009    BytePtr current_sp = (BytePtr) current_stack_pointer();
2010   
2011    if ((current_sp >= vs->low) &&
2012        (current_sp < vs->high)) {
2013      return
2014        handle_signal_on_foreign_stack(tcr,
2015                                       suspend_resume_handler,
2016                                       signum,
2017                                       info,
2018                                       context,
2019                                       (LispObj)__builtin_return_address(0)
2020#ifdef DARWIN_GS_HACK
2021                                       ,gs_was_tcr
2022#endif
2023                                       );
2024    } else {
2025      /* If we're not on the value stack, we pretty much have to be on
2026         the C stack.  Just run the handler. */
2027#ifdef DARWIN_GS_HACK
2028      if (gs_was_tcr) {
2029        set_gs_address(tcr);
2030      }
2031#endif
2032    }
2033  }
2034  suspend_resume_handler(signum, info, context);
2035}
2036
2037
2038#else /* altstack works */
2039void
2040altstack_suspend_resume_handler(int signum, siginfo_t *info, ExceptionInformation  *context)
2041{
2042#ifdef DARWIN_GS_HACK
2043  Boolean gs_was_tcr = ensure_gs_pthread();
2044#endif
2045  TCR* tcr = get_tcr(true);
2046  handle_signal_on_foreign_stack(tcr,
2047                                 suspend_resume_handler,
2048                                 signum,
2049                                 info,
2050                                 context,
2051                                 (LispObj)__builtin_return_address(0)
2052#ifdef DARWIN_GS_HACK
2053                                 ,gs_was_tcr
2054#endif
2055                                 );
2056}
2057#endif
2058#endif
2059
2060
2061/* This should only be called when the tcr_area_lock is held */
2062void
2063empty_tcr_stacks(TCR *tcr)
2064{
2065  if (tcr) {
2066    area *a;
2067
2068    tcr->valence = TCR_STATE_FOREIGN;
2069    a = tcr->vs_area;
2070    if (a) {
2071      a->active = a->high;
2072    }
2073    a = tcr->ts_area;
2074    if (a) {
2075      a->active = a->high;
2076    }
2077    a = tcr->cs_area;
2078    if (a) {
2079      a->active = a->high;
2080    }
2081  }
2082}
2083
2084#ifdef WINDOWS
2085void
2086thread_kill_handler(int signum, siginfo_t *info, ExceptionInformation *xp)
2087{
2088}
2089#else
2090void
2091thread_kill_handler(int signum, siginfo_t *info, ExceptionInformation *xp)
2092{
2093#ifdef DARWIN_GS_HACK
2094  Boolean gs_was_tcr = ensure_gs_pthread();
2095#endif
2096  TCR *tcr = get_tcr(false);
2097  sigset_t mask;
2098
2099  sigemptyset(&mask);
2100
2101  empty_tcr_stacks(tcr);
2102
2103  pthread_sigmask(SIG_SETMASK,&mask,NULL);
2104  pthread_exit(NULL);
2105}
2106#endif
2107
2108#ifndef WINDOWS
2109#ifndef USE_SIGALTSTACK
2110void
2111arbstack_thread_kill_handler(int signum, siginfo_t *info, ExceptionInformation *context)
2112{
2113#ifdef DARWIN_GS_HACK
2114  Boolean gs_was_tcr = ensure_gs_pthread();
2115#endif
2116  TCR *tcr = get_interrupt_tcr(false);
2117  area *vs = tcr->vs_area;
2118  BytePtr current_sp = (BytePtr) current_stack_pointer();
2119
2120  if ((current_sp >= vs->low) &&
2121      (current_sp < vs->high)) {
2122    handle_signal_on_foreign_stack(tcr,
2123                                   thread_kill_handler,
2124                                   signum,
2125                                   info,
2126                                   context,
2127                                   (LispObj)__builtin_return_address(0)
2128#ifdef DARWIN_GS_HACK
2129                                   ,gs_was_tcr
2130#endif
2131                                   );
2132  } else {
2133    /* If we're not on the value stack, we pretty much have to be on
2134       the C stack.  Just run the handler. */
2135#ifdef DARWIN_GS_HACK
2136    if (gs_was_tcr) {
2137      set_gs_address(tcr);
2138    }
2139#endif
2140    thread_kill_handler(signum, info, context);
2141  }
2142}
2143
2144
2145#else
2146void
2147altstack_thread_kill_handler(int signum, siginfo_t *info, ExceptionInformation *context)
2148{
2149#ifdef DARWIN_GS_HACK
2150  Boolean gs_was_tcr = ensure_gs_pthread();
2151#endif
2152  TCR* tcr = get_tcr(true);
2153  handle_signal_on_foreign_stack(tcr,
2154                                 thread_kill_handler,
2155                                 signum,
2156                                 info,
2157                                 context,
2158                                 (LispObj)__builtin_return_address(0)
2159#ifdef DARWIN_GS_HACK
2160                                 ,gs_was_tcr
2161#endif
2162                                 );
2163}
2164#endif
2165#endif
2166
2167#ifdef USE_SIGALTSTACK
2168#define SUSPEND_RESUME_HANDLER altstack_suspend_resume_handler
2169#define THREAD_KILL_HANDLER altstack_thread_kill_handler
2170#else
2171#define SUSPEND_RESUME_HANDLER arbstack_suspend_resume_handler
2172#define THREAD_KILL_HANDLER arbstack_thread_kill_handler
2173#endif
2174
2175#ifdef WINDOWS
2176void
2177thread_signal_setup()
2178{
2179}
2180#else
2181void
2182thread_signal_setup()
2183{
2184  thread_suspend_signal = SIG_SUSPEND_THREAD;
2185  thread_kill_signal = SIG_KILL_THREAD;
2186
2187  install_signal_handler(thread_suspend_signal, (void *)SUSPEND_RESUME_HANDLER);
2188  install_signal_handler(thread_kill_signal, (void *)THREAD_KILL_HANDLER);
2189}
2190#endif
2191
2192void
2193enable_fp_exceptions()
2194{
2195}
2196
2197void
2198exception_init()
2199{
2200  install_pmcl_exception_handlers();
2201}
2202
2203void
2204adjust_exception_pc(ExceptionInformation *xp, int delta)
2205{
2206  xpPC(xp) += delta;
2207}
2208
2209/*
2210  Lower (move toward 0) the "end" of the soft protected area associated
2211  with a by a page, if we can.
2212*/
2213
2214void
2215
2216adjust_soft_protection_limit(area *a)
2217{
2218  char *proposed_new_soft_limit = a->softlimit - 4096;
2219  protected_area_ptr p = a->softprot;
2220 
2221  if (proposed_new_soft_limit >= (p->start+16384)) {
2222    p->end = proposed_new_soft_limit;
2223    p->protsize = p->end-p->start;
2224    a->softlimit = proposed_new_soft_limit;
2225  }
2226  protect_area(p);
2227}
2228
2229void
2230restore_soft_stack_limit(unsigned restore_tsp)
2231{
2232  TCR *tcr = get_tcr(false);
2233  area *a;
2234 
2235  if (restore_tsp) {
2236    a = tcr->ts_area;
2237  } else {
2238    a = tcr->vs_area;
2239  }
2240  adjust_soft_protection_limit(a);
2241}
2242
2243
2244#ifdef USE_SIGALTSTACK
2245void
2246setup_sigaltstack(area *a)
2247{
2248  stack_t stack;
2249  stack.ss_sp = a->low;
2250  a->low += SIGSTKSZ*8;
2251  stack.ss_size = SIGSTKSZ*8;
2252  stack.ss_flags = 0;
2253  mmap(stack.ss_sp,stack.ss_size, PROT_READ|PROT_WRITE|PROT_EXEC,MAP_FIXED|MAP_ANON|MAP_PRIVATE,-1,0);
2254  if (sigaltstack(&stack, NULL) != 0) {
2255    perror("sigaltstack");
2256    exit(-1);
2257  }
2258}
2259#endif
2260
2261extern opcode egc_write_barrier_start, egc_write_barrier_end,
2262  egc_set_hash_key_conditional, egc_set_hash_key_conditional_success_test,
2263  egc_store_node_conditional_success_end,
2264  egc_store_node_conditional_success_test,egc_store_node_conditional,
2265  egc_set_hash_key, egc_gvset, egc_rplacd;
2266
2267/* We use (extremely) rigidly defined instruction sequences for consing,
2268   mostly so that 'pc_luser_xp()' knows what to do if a thread is interrupted
2269   while consing.
2270
2271   Note that we can usually identify which of these instructions is about
2272   to be executed by a stopped thread without comparing all of the bytes
2273   to those at the stopped program counter, but we generally need to
2274   know the sizes of each of these instructions.
2275*/
2276
2277#ifdef X8664
2278opcode load_allocptr_reg_from_tcr_save_allocptr_instruction[] =
2279#ifdef WINDOWS
2280  {0x49,0x8b,0x9b,0xd8,0x00,0x00,0x00}
2281#else
2282  {0x65,0x48,0x8b,0x1c,0x25,0xd8,0x00,0x00,0x00}
2283#endif
2284;
2285opcode compare_allocptr_reg_to_tcr_save_allocbase_instruction[] =
2286#ifdef WINDOWS
2287  {0x49,0x3b,0x9b,0xe0,0x00,0x00,0x00}
2288#else
2289  {0x65,0x48,0x3b,0x1c,0x25,0xe0,0x00,0x00,0x00}
2290#endif
2291
2292;
2293opcode branch_around_alloc_trap_instruction[] =
2294  {0x77,0x02};
2295opcode alloc_trap_instruction[] =
2296  {0xcd,0xc5};
2297opcode clear_tcr_save_allocptr_tag_instruction[] =
2298#ifdef WINDOWS
2299  {0x41,0x80,0xa3,0xd8,0x00,0x00,0x00,0xf0}
2300#else
2301  {0x65,0x80,0x24,0x25,0xd8,0x00,0x00,0x00,0xf0}
2302#endif
2303;
2304opcode set_allocptr_header_instruction[] =
2305  {0x48,0x89,0x43,0xf3};
2306
2307
2308alloc_instruction_id
2309recognize_alloc_instruction(pc program_counter)
2310{
2311  switch(program_counter[0]) {
2312  case 0xcd: return ID_alloc_trap_instruction;
2313  /* 0x7f is jg, which we used to use here instead of ja */
2314  case 0x7f:
2315  case 0x77: return ID_branch_around_alloc_trap_instruction;
2316  case 0x48: return ID_set_allocptr_header_instruction;
2317#ifdef WINDOWS
2318  case 0x41: return ID_clear_tcr_save_allocptr_tag_instruction;
2319  case 0x49:
2320    switch(program_counter[1]) {
2321    case 0x8b: return ID_load_allocptr_reg_from_tcr_save_allocptr_instruction;
2322    case 0x3b: return ID_compare_allocptr_reg_to_tcr_save_allocbase_instruction;
2323    }
2324#else
2325  case 0x65: 
2326    switch(program_counter[1]) {
2327    case 0x80: return ID_clear_tcr_save_allocptr_tag_instruction;
2328    case 0x48:
2329      switch(program_counter[2]) {
2330      case 0x3b: return ID_compare_allocptr_reg_to_tcr_save_allocbase_instruction;
2331      case 0x8b: return ID_load_allocptr_reg_from_tcr_save_allocptr_instruction;
2332      }
2333    }
2334#endif
2335  default: break;
2336  }
2337  return ID_unrecognized_alloc_instruction;
2338}
2339#endif
2340#ifdef X8632
2341#ifdef WIN32_ES_HACK
2342/* Win32 keeps the TCR in %es */
2343#define TCR_SEG_PREFIX 0x26     /* %es: */
2344#else
2345/* Other platfroms use %fs */
2346#define TCR_SEG_PREFIX 0x64     /* %fs: */
2347#endif
2348opcode load_allocptr_reg_from_tcr_save_allocptr_instruction[] =
2349  {TCR_SEG_PREFIX,0x8b,0x0d,0x84,0x00,0x00,0x00};
2350opcode compare_allocptr_reg_to_tcr_save_allocbase_instruction[] =
2351  {TCR_SEG_PREFIX,0x3b,0x0d,0x88,0x00,0x00,0x00};
2352opcode branch_around_alloc_trap_instruction[] =
2353  {0x77,0x02};
2354opcode alloc_trap_instruction[] =
2355  {0xcd,0xc5};
2356opcode clear_tcr_save_allocptr_tag_instruction[] =
2357  {TCR_SEG_PREFIX,0x80,0x25,0x84,0x00,0x00,0x00,0xf8};
2358opcode set_allocptr_header_instruction[] =
2359  {0x0f,0x7e,0x41,0xfa};
2360
2361alloc_instruction_id
2362recognize_alloc_instruction(pc program_counter)
2363{
2364  switch(program_counter[0]) {
2365  case 0xcd: return ID_alloc_trap_instruction;
2366  /* 0x7f is jg, which we used to use here instead of ja */
2367  case 0x7f:
2368  case 0x77: return ID_branch_around_alloc_trap_instruction;
2369  case 0x0f: return ID_set_allocptr_header_instruction;
2370  case TCR_SEG_PREFIX: 
2371    switch(program_counter[1]) {
2372    case 0x80: return ID_clear_tcr_save_allocptr_tag_instruction;
2373    case 0x3b: return ID_compare_allocptr_reg_to_tcr_save_allocbase_instruction;
2374    case 0x8b: return ID_load_allocptr_reg_from_tcr_save_allocptr_instruction;
2375    }
2376  }
2377  return ID_unrecognized_alloc_instruction;
2378}
2379#endif     
2380
2381void
2382pc_luser_xp(ExceptionInformation *xp, TCR *tcr, signed_natural *interrupt_displacement)
2383{
2384  pc program_counter = (pc)xpPC(xp);
2385  int allocptr_tag = fulltag_of((LispObj)(tcr->save_allocptr));
2386
2387  if (allocptr_tag != 0) {
2388    alloc_instruction_id state = recognize_alloc_instruction(program_counter);
2389    signed_natural
2390      disp = (allocptr_tag == fulltag_cons) ?
2391      sizeof(cons) - fulltag_cons :
2392#ifdef X8664
2393      xpGPR(xp,Iimm1);
2394#else
2395      xpGPR(xp,Iimm0);
2396#endif
2397    LispObj new_vector;
2398
2399    if ((state == ID_unrecognized_alloc_instruction) ||
2400        ((state == ID_set_allocptr_header_instruction) &&
2401         (allocptr_tag != fulltag_misc))) {
2402      Bug(xp, "Can't determine state of thread 0x" LISP ", interrupted during memory allocation", tcr);
2403    }
2404    switch(state) {
2405    case ID_set_allocptr_header_instruction:
2406      /* We were consing a vector and we won.  Set the header of the
2407         new vector (in the allocptr register) to the header in %rax
2408         (%mm0 on ia32) and skip over this instruction, then fall into
2409         the next case. */
2410      new_vector = xpGPR(xp,Iallocptr);
2411      deref(new_vector,0) = 
2412#ifdef X8664
2413        xpGPR(xp,Iimm0)
2414#else
2415        xpMMXreg(xp,Imm0)
2416#endif
2417        ;
2418
2419      xpPC(xp) += sizeof(set_allocptr_header_instruction);
2420      /* Fall thru */
2421    case ID_clear_tcr_save_allocptr_tag_instruction:
2422      tcr->save_allocptr = (void *)(((LispObj)tcr->save_allocptr) & ~fulltagmask);
2423      xpPC(xp) += sizeof(clear_tcr_save_allocptr_tag_instruction);
2424      break;
2425    case ID_alloc_trap_instruction:
2426      /* If we're looking at another thread, we're pretty much committed to
2427         taking the trap.  We don't want the allocptr register to be pointing
2428         into the heap, so make it point to (- VOID_ALLOCPTR disp), where 'disp'
2429         was determined above.
2430      */
2431      if (interrupt_displacement == NULL) {
2432        xpGPR(xp,Iallocptr) = VOID_ALLOCPTR - disp;
2433        tcr->save_allocptr = (void *)(VOID_ALLOCPTR - disp);
2434      } else {
2435        /* Back out, and tell the caller how to resume the allocation attempt */
2436        *interrupt_displacement = disp;
2437        xpGPR(xp,Iallocptr) = VOID_ALLOCPTR;
2438        tcr->save_allocptr += disp;
2439        xpPC(xp) -= (sizeof(branch_around_alloc_trap_instruction)+
2440                     sizeof(compare_allocptr_reg_to_tcr_save_allocbase_instruction) +
2441                     sizeof(load_allocptr_reg_from_tcr_save_allocptr_instruction));
2442      }
2443      break;
2444    case ID_branch_around_alloc_trap_instruction:
2445      /* If we'd take the branch - which is a "ja" - around the alloc trap,
2446         we might as well finish the allocation.  Otherwise, back out of the
2447         attempt. */
2448      {
2449        int flags = (int)eflags_register(xp);
2450       
2451        if ((!(flags & (1 << X86_ZERO_FLAG_BIT))) &&
2452            (!(flags & (1 << X86_CARRY_FLAG_BIT)))) {
2453          /* The branch (ja) would have been taken.  Emulate taking it. */
2454          xpPC(xp) += (sizeof(branch_around_alloc_trap_instruction)+
2455                       sizeof(alloc_trap_instruction));
2456          if (allocptr_tag == fulltag_misc) {
2457            /* Slap the header on the new uvector */
2458            new_vector = xpGPR(xp,Iallocptr);
2459            deref(new_vector,0) = xpGPR(xp,Iimm0);
2460            xpPC(xp) += sizeof(set_allocptr_header_instruction);
2461          }
2462          tcr->save_allocptr = (void *)(((LispObj)tcr->save_allocptr) & ~fulltagmask);
2463          xpPC(xp) += sizeof(clear_tcr_save_allocptr_tag_instruction);
2464        } else {
2465          /* Back up */
2466          xpPC(xp) -= (sizeof(compare_allocptr_reg_to_tcr_save_allocbase_instruction) +
2467                       sizeof(load_allocptr_reg_from_tcr_save_allocptr_instruction));
2468          xpGPR(xp,Iallocptr) = VOID_ALLOCPTR;
2469          if (interrupt_displacement) {
2470            *interrupt_displacement = disp;
2471            tcr->save_allocptr += disp;
2472          } else {
2473            tcr->save_allocptr = (void *)(VOID_ALLOCPTR-disp);
2474          }
2475        }
2476      }
2477      break;
2478    case ID_compare_allocptr_reg_to_tcr_save_allocbase_instruction:
2479      xpGPR(xp,Iallocptr) = VOID_ALLOCPTR;
2480      xpPC(xp) -= sizeof(load_allocptr_reg_from_tcr_save_allocptr_instruction);
2481      /* Fall through */
2482    case ID_load_allocptr_reg_from_tcr_save_allocptr_instruction:
2483      if (interrupt_displacement) {
2484        tcr->save_allocptr += disp;
2485        *interrupt_displacement = disp;
2486      } else {
2487        tcr->save_allocptr = (void *)(VOID_ALLOCPTR-disp);
2488      }
2489      break;
2490    default: 
2491      break;
2492    }
2493    return;
2494  }
2495  if ((program_counter >= &egc_write_barrier_start) &&
2496      (program_counter < &egc_write_barrier_end)) {
2497    LispObj *ea = 0, val, root = 0;
2498    bitvector refbits = (bitvector)(lisp_global(REFBITS));
2499    Boolean need_store = true, need_check_memo = true, need_memoize_root = false;
2500
2501    if (program_counter >= &egc_set_hash_key_conditional) {
2502      if ((program_counter < &egc_set_hash_key_conditional_success_test) ||
2503          ((program_counter == &egc_set_hash_key_conditional_success_test) &&
2504           !(eflags_register(xp) & (1 << X86_ZERO_FLAG_BIT)))) {
2505        /* Back up the PC, try again */
2506        xpPC(xp) = (LispObj) &egc_set_hash_key_conditional;
2507        return;
2508      }
2509      /* The conditional store succeeded.  Set the refbit, return to ra0 */
2510      val = xpGPR(xp,Iarg_z);
2511#ifdef X8664
2512      root = xpGPR(xp,Iarg_x);
2513      ea = (LispObj*)(root + (unbox_fixnum((signed_natural) xpGPR(xp,Itemp0))));
2514#else
2515      root = xpGPR(xp,Itemp1);
2516      ea = (LispObj *)(root + misc_data_offset + xpGPR(xp,Itemp0));
2517#endif
2518      need_memoize_root = true;
2519      need_store = false;
2520      xpGPR(xp,Iarg_z) = t_value;
2521    } else if (program_counter >= &egc_store_node_conditional) {
2522      if ((program_counter < &egc_store_node_conditional_success_test) ||
2523          ((program_counter == &egc_store_node_conditional_success_test) &&
2524           !(eflags_register(xp) & (1 << X86_ZERO_FLAG_BIT)))) {
2525        /* Back up the PC, try again */
2526        xpPC(xp) = (LispObj) &egc_store_node_conditional;
2527        return;
2528      }
2529      if (program_counter >= &egc_store_node_conditional_success_end) {
2530        return;
2531      }
2532
2533      /* The conditional store succeeded.  Set the refbit, return to ra0 */
2534      val = xpGPR(xp,Iarg_z);
2535#ifdef X8664
2536      ea = (LispObj*)(xpGPR(xp,Iarg_x) + (unbox_fixnum((signed_natural)
2537                                                       xpGPR(xp,Itemp0))));
2538#else
2539      ea = (LispObj *)(misc_data_offset + xpGPR(xp,Itemp1) + xpGPR(xp,Itemp0));
2540#endif
2541      xpGPR(xp,Iarg_z) = t_value;
2542      need_store = false;
2543    } else if (program_counter >= &egc_set_hash_key) {
2544#ifdef X8664
2545      root = xpGPR(xp,Iarg_x);
2546#else
2547      root = xpGPR(xp,Itemp0);
2548#endif
2549      ea = (LispObj *) (root+xpGPR(xp,Iarg_y)+misc_data_offset);
2550      val = xpGPR(xp,Iarg_z);
2551      need_memoize_root = true;
2552    } else if (program_counter >= &egc_gvset) {
2553#ifdef X8664
2554      ea = (LispObj *) (xpGPR(xp,Iarg_x)+xpGPR(xp,Iarg_y)+misc_data_offset);
2555#else
2556      ea = (LispObj *) (xpGPR(xp,Itemp0)+xpGPR(xp,Iarg_y)+misc_data_offset);
2557#endif
2558      val = xpGPR(xp,Iarg_z);
2559    } else if (program_counter >= &egc_rplacd) {
2560      ea = (LispObj *) untag(xpGPR(xp,Iarg_y));
2561      val = xpGPR(xp,Iarg_z);
2562    } else {                      /* egc_rplaca */
2563      ea =  ((LispObj *) untag(xpGPR(xp,Iarg_y)))+1;
2564      val = xpGPR(xp,Iarg_z);
2565    }
2566    if (need_store) {
2567      *ea = val;
2568    }
2569    if (need_check_memo) {
2570      natural  bitnumber = area_dnode(ea, lisp_global(HEAP_START));
2571      if ((bitnumber < lisp_global(OLDSPACE_DNODE_COUNT)) &&
2572          ((LispObj)ea < val)) {
2573        atomic_set_bit(refbits, bitnumber);
2574        if (need_memoize_root) {
2575          bitnumber = area_dnode(root, lisp_global(HEAP_START));
2576          atomic_set_bit(refbits, bitnumber);
2577        }
2578      }
2579    }
2580    {
2581      /* These subprimitives are called via CALL/RET; need
2582         to pop the return address off the stack and set
2583         the PC there. */
2584      LispObj *sp = (LispObj *)xpGPR(xp,Isp), ra = *sp++;
2585      xpPC(xp) = ra;
2586      xpGPR(xp,Isp)=(LispObj)sp;
2587    }
2588    return;
2589  }
2590}
2591
2592
2593void
2594normalize_tcr(ExceptionInformation *xp, TCR *tcr, Boolean is_other_tcr)
2595{
2596  void *cur_allocptr = (void *)(tcr->save_allocptr);
2597  LispObj lisprsp;
2598  area *a;
2599
2600  if (xp) {
2601    if (is_other_tcr) {
2602      pc_luser_xp(xp, tcr, NULL);
2603    }
2604    a = tcr->vs_area;
2605    lisprsp = xpGPR(xp, Isp);
2606    if (((BytePtr)lisprsp >= a->low) &&
2607        ((BytePtr)lisprsp < a->high)) {
2608      a->active = (BytePtr)lisprsp;
2609    } else {
2610      a->active = (BytePtr) tcr->save_vsp;
2611    }
2612    a = tcr->ts_area;
2613    a->active = (BytePtr) tcr->save_tsp;
2614  } else {
2615    /* In ff-call; get area active pointers from tcr */
2616    tcr->vs_area->active = (BytePtr) tcr->save_vsp;
2617    tcr->ts_area->active = (BytePtr) tcr->save_tsp;
2618  }
2619  if (cur_allocptr) {
2620    update_bytes_allocated(tcr, cur_allocptr);
2621  }
2622  tcr->save_allocbase = (void *)VOID_ALLOCPTR;
2623  if (fulltag_of((LispObj)(tcr->save_allocptr)) == 0) {
2624    tcr->save_allocptr = (void *)VOID_ALLOCPTR;
2625  }
2626}
2627
2628
2629/* Suspend and "normalize" other tcrs, then call a gc-like function
2630   in that context.  Resume the other tcrs, then return what the
2631   function returned */
2632
2633TCR *gc_tcr = NULL;
2634
2635
2636signed_natural
2637gc_like_from_xp(ExceptionInformation *xp, 
2638                signed_natural(*fun)(TCR *, signed_natural), 
2639                signed_natural param)
2640{
2641  TCR *tcr = get_tcr(false), *other_tcr;
2642  int result;
2643  signed_natural inhibit;
2644
2645  suspend_other_threads(true);
2646  inhibit = (signed_natural)(lisp_global(GC_INHIBIT_COUNT));
2647  if (inhibit != 0) {
2648    if (inhibit > 0) {
2649      lisp_global(GC_INHIBIT_COUNT) = (LispObj)(-inhibit);
2650    }
2651    resume_other_threads(true);
2652    gc_deferred++;
2653    return 0;
2654  }
2655  gc_deferred = 0;
2656
2657  gc_tcr = tcr;
2658
2659  /* This is generally necessary if the current thread invoked the GC
2660     via an alloc trap, and harmless if the GC was invoked via a GC
2661     trap.  (It's necessary in the first case because the "allocptr"
2662     register - %rbx - may be pointing into the middle of something
2663     below tcr->save_allocbase, and we wouldn't want the GC to see
2664     that bogus pointer.) */
2665  xpGPR(xp, Iallocptr) = VOID_ALLOCPTR; 
2666
2667  normalize_tcr(xp, tcr, false);
2668
2669
2670  for (other_tcr = tcr->next; other_tcr != tcr; other_tcr = other_tcr->next) {
2671    if (other_tcr->pending_exception_context) {
2672      other_tcr->gc_context = other_tcr->pending_exception_context;
2673    } else if (other_tcr->valence == TCR_STATE_LISP) {
2674      other_tcr->gc_context = other_tcr->suspend_context;
2675    } else {
2676      /* no pending exception, didn't suspend in lisp state:
2677         must have executed a synchronous ff-call.
2678      */
2679      other_tcr->gc_context = NULL;
2680    }
2681    normalize_tcr(other_tcr->gc_context, other_tcr, true);
2682  }
2683   
2684
2685
2686  result = fun(tcr, param);
2687
2688  other_tcr = tcr;
2689  do {
2690    other_tcr->gc_context = NULL;
2691    other_tcr = other_tcr->next;
2692  } while (other_tcr != tcr);
2693
2694  gc_tcr = NULL;
2695
2696  resume_other_threads(true);
2697
2698  return result;
2699
2700}
2701
2702signed_natural
2703purify_from_xp(ExceptionInformation *xp, signed_natural param)
2704{
2705  return gc_like_from_xp(xp, purify, param);
2706}
2707
2708signed_natural
2709impurify_from_xp(ExceptionInformation *xp, signed_natural param)
2710{
2711  return gc_like_from_xp(xp, impurify, param);
2712}
2713
2714/* Returns #bytes freed by invoking GC */
2715
2716signed_natural
2717gc_from_tcr(TCR *tcr, signed_natural param)
2718{
2719  area *a;
2720  BytePtr oldfree, newfree;
2721  BytePtr oldend, newend;
2722
2723#if 0
2724  fprintf(dbgout, "Start GC  in 0x" LISP "\n", tcr);
2725#endif
2726  a = active_dynamic_area;
2727  oldend = a->high;
2728  oldfree = a->active;
2729  gc(tcr, param);
2730  newfree = a->active;
2731  newend = a->high;
2732#if 0
2733  fprintf(dbgout, "End GC  in 0x" LISP "\n", tcr);
2734#endif
2735  return ((oldfree-newfree)+(newend-oldend));
2736}
2737
2738signed_natural
2739gc_from_xp(ExceptionInformation *xp, signed_natural param)
2740{
2741  signed_natural status = gc_like_from_xp(xp, gc_from_tcr, param);
2742
2743  freeGCptrs();
2744  return status;
2745}
2746
2747#ifdef DARWIN
2748
2749#define TCR_FROM_EXCEPTION_PORT(p) ((TCR *)((natural)p))
2750#define TCR_TO_EXCEPTION_PORT(tcr) ((mach_port_t)((natural)(tcr)))
2751
2752extern void pseudo_sigreturn(void);
2753
2754
2755
2756#define LISP_EXCEPTIONS_HANDLED_MASK \
2757 (EXC_MASK_SOFTWARE | EXC_MASK_BAD_ACCESS | EXC_MASK_BAD_INSTRUCTION | EXC_MASK_ARITHMETIC)
2758
2759/* (logcount LISP_EXCEPTIONS_HANDLED_MASK) */
2760#define NUM_LISP_EXCEPTIONS_HANDLED 4
2761
2762typedef struct {
2763  int foreign_exception_port_count;
2764  exception_mask_t         masks[NUM_LISP_EXCEPTIONS_HANDLED];
2765  mach_port_t              ports[NUM_LISP_EXCEPTIONS_HANDLED];
2766  exception_behavior_t behaviors[NUM_LISP_EXCEPTIONS_HANDLED];
2767  thread_state_flavor_t  flavors[NUM_LISP_EXCEPTIONS_HANDLED];
2768} MACH_foreign_exception_state;
2769
2770
2771
2772
2773/*
2774  Mach's exception mechanism works a little better than its signal
2775  mechanism (and, not incidentally, it gets along with GDB a lot
2776  better.
2777
2778  Initially, we install an exception handler to handle each native
2779  thread's exceptions.  This process involves creating a distinguished
2780  thread which listens for kernel exception messages on a set of
2781  0 or more thread exception ports.  As threads are created, they're
2782  added to that port set; a thread's exception port is destroyed
2783  (and therefore removed from the port set) when the thread exits.
2784
2785  A few exceptions can be handled directly in the handler thread;
2786  others require that we resume the user thread (and that the
2787  exception thread resumes listening for exceptions.)  The user
2788  thread might eventually want to return to the original context
2789  (possibly modified somewhat.)
2790
2791  As it turns out, the simplest way to force the faulting user
2792  thread to handle its own exceptions is to do pretty much what
2793  signal() does: the exception handlng thread sets up a sigcontext
2794  on the user thread's stack and forces the user thread to resume
2795  execution as if a signal handler had been called with that
2796  context as an argument.  We can use a distinguished UUO at a
2797  distinguished address to do something like sigreturn(); that'll
2798  have the effect of resuming the user thread's execution in
2799  the (pseudo-) signal context.
2800
2801  Since:
2802    a) we have miles of code in C and in Lisp that knows how to
2803    deal with Linux sigcontexts
2804    b) Linux sigcontexts contain a little more useful information
2805    (the DAR, DSISR, etc.) than their Darwin counterparts
2806    c) we have to create a sigcontext ourselves when calling out
2807    to the user thread: we aren't really generating a signal, just
2808    leveraging existing signal-handling code.
2809
2810  we create a Linux sigcontext struct.
2811
2812  Simple ?  Hopefully from the outside it is ...
2813
2814  We want the process of passing a thread's own context to it to
2815  appear to be atomic: in particular, we don't want the GC to suspend
2816  a thread that's had an exception but has not yet had its user-level
2817  exception handler called, and we don't want the thread's exception
2818  context to be modified by a GC while the Mach handler thread is
2819  copying it around.  On Linux (and on Jaguar), we avoid this issue
2820  because (a) the kernel sets up the user-level signal handler and
2821  (b) the signal handler blocks signals (including the signal used
2822  by the GC to suspend threads) until tcr->xframe is set up.
2823
2824  The GC and the Mach server thread therefore contend for the lock
2825  "mach_exception_lock".  The Mach server thread holds the lock
2826  when copying exception information between the kernel and the
2827  user thread; the GC holds this lock during most of its execution
2828  (delaying exception processing until it can be done without
2829  GC interference.)
2830
2831*/
2832
2833#ifdef PPC64
2834#define C_REDZONE_LEN           320
2835#define C_STK_ALIGN             32
2836#else
2837#define C_REDZONE_LEN           224
2838#define C_STK_ALIGN             16
2839#endif
2840#define C_PARAMSAVE_LEN         64
2841#define C_LINKAGE_LEN           48
2842
2843#define TRUNC_DOWN(a,b,c)  (((((natural)a)-(b))/(c)) * (c))
2844
2845void
2846fatal_mach_error(char *format, ...);
2847
2848#define MACH_CHECK_ERROR(context,x) if (x != KERN_SUCCESS) {fatal_mach_error("Mach error while %s : %d", context, x);}
2849
2850
2851void
2852restore_mach_thread_state(mach_port_t thread, ExceptionInformation *pseudosigcontext)
2853{
2854  kern_return_t kret;
2855#if WORD_SIZE == 64
2856  MCONTEXT_T mc = UC_MCONTEXT(pseudosigcontext);
2857#else
2858  mcontext_t mc = UC_MCONTEXT(pseudosigcontext);
2859#endif
2860
2861  /* Set the thread's FP state from the pseudosigcontext */
2862#if WORD_SIZE == 64
2863  kret = thread_set_state(thread,
2864                          x86_FLOAT_STATE64,
2865                          (thread_state_t)&(mc->__fs),
2866                          x86_FLOAT_STATE64_COUNT);
2867#else
2868  kret = thread_set_state(thread,
2869                          x86_FLOAT_STATE32,
2870                          (thread_state_t)&(mc->__fs),
2871                          x86_FLOAT_STATE32_COUNT);
2872#endif
2873  MACH_CHECK_ERROR("setting thread FP state", kret);
2874
2875  /* The thread'll be as good as new ... */
2876#if WORD_SIZE == 64
2877  kret = thread_set_state(thread,
2878                          x86_THREAD_STATE64,
2879                          (thread_state_t)&(mc->__ss),
2880                          x86_THREAD_STATE64_COUNT);
2881#else
2882  kret = thread_set_state(thread, 
2883                          x86_THREAD_STATE32,
2884                          (thread_state_t)&(mc->__ss),
2885                          x86_THREAD_STATE32_COUNT);
2886#endif
2887  MACH_CHECK_ERROR("setting thread state", kret);
2888} 
2889
2890/* This code runs in the exception handling thread, in response
2891   to an attempt to execute the UU0 at "pseudo_sigreturn" (e.g.,
2892   in response to a call to pseudo_sigreturn() from the specified
2893   user thread.
2894   Find that context (the user thread's R3 points to it), then
2895   use that context to set the user thread's state.  When this
2896   function's caller returns, the Mach kernel will resume the
2897   user thread.
2898*/
2899
2900kern_return_t
2901do_pseudo_sigreturn(mach_port_t thread, TCR *tcr)
2902{
2903  ExceptionInformation *xp;
2904
2905#ifdef DEBUG_MACH_EXCEPTIONS
2906  fprintf(dbgout, "doing pseudo_sigreturn for 0x%x\n",tcr);
2907#endif
2908  xp = tcr->pending_exception_context;
2909  if (xp) {
2910    tcr->pending_exception_context = NULL;
2911    tcr->valence = TCR_STATE_LISP;
2912    restore_mach_thread_state(thread, xp);
2913    raise_pending_interrupt(tcr);
2914  } else {
2915    Bug(NULL, "no xp here!\n");
2916  }
2917#ifdef DEBUG_MACH_EXCEPTIONS
2918  fprintf(dbgout, "did pseudo_sigreturn for 0x%x\n",tcr);
2919#endif
2920  return KERN_SUCCESS;
2921} 
2922
2923ExceptionInformation *
2924create_thread_context_frame(mach_port_t thread, 
2925                            natural *new_stack_top,
2926                            siginfo_t **info_ptr,
2927                            TCR *tcr,
2928#ifdef X8664
2929                            x86_thread_state64_t *ts
2930#else
2931                            x86_thread_state32_t *ts
2932#endif
2933                            )
2934{
2935  mach_msg_type_number_t thread_state_count;
2936  ExceptionInformation *pseudosigcontext;
2937#ifdef X8664
2938  MCONTEXT_T mc;
2939#else
2940  mcontext_t mc;
2941#endif
2942  natural stackp;
2943
2944#ifdef X8664 
2945  stackp = (LispObj) find_foreign_rsp(ts->__rsp,tcr->cs_area,tcr);
2946  stackp = TRUNC_DOWN(stackp, C_REDZONE_LEN, C_STK_ALIGN);
2947#else
2948  stackp = (LispObj) find_foreign_rsp(ts->__esp, tcr->cs_area, tcr);
2949#endif
2950  stackp = TRUNC_DOWN(stackp, sizeof(siginfo_t), C_STK_ALIGN);
2951  if (info_ptr) {
2952    *info_ptr = (siginfo_t *)stackp;
2953  }
2954  stackp = TRUNC_DOWN(stackp,sizeof(*pseudosigcontext), C_STK_ALIGN);
2955  pseudosigcontext = (ExceptionInformation *) ptr_from_lispobj(stackp);
2956
2957  stackp = TRUNC_DOWN(stackp, sizeof(*mc), C_STK_ALIGN);
2958  mc = (MCONTEXT_T) ptr_from_lispobj(stackp);
2959 
2960  memmove(&(mc->__ss),ts,sizeof(*ts));
2961
2962#ifdef X8664
2963  thread_state_count = x86_FLOAT_STATE64_COUNT;
2964  thread_get_state(thread,
2965                   x86_FLOAT_STATE64,
2966                   (thread_state_t)&(mc->__fs),
2967                   &thread_state_count);
2968
2969  thread_state_count = x86_EXCEPTION_STATE64_COUNT;
2970  thread_get_state(thread,
2971                   x86_EXCEPTION_STATE64,
2972                   (thread_state_t)&(mc->__es),
2973                   &thread_state_count);
2974#else
2975  thread_state_count = x86_FLOAT_STATE32_COUNT;
2976  thread_get_state(thread,
2977                   x86_FLOAT_STATE32,
2978                   (thread_state_t)&(mc->__fs),
2979                   &thread_state_count);
2980
2981  thread_state_count = x86_EXCEPTION_STATE32_COUNT;
2982  thread_get_state(thread,
2983                   x86_EXCEPTION_STATE32,
2984                   (thread_state_t)&(mc->__es),
2985                   &thread_state_count);
2986#endif
2987
2988
2989  UC_MCONTEXT(pseudosigcontext) = mc;
2990  if (new_stack_top) {
2991    *new_stack_top = stackp;
2992  }
2993  return pseudosigcontext;
2994}
2995
2996/*
2997  This code sets up the user thread so that it executes a "pseudo-signal
2998  handler" function when it resumes.  Create a fake ucontext struct
2999  on the thread's stack and pass it as an argument to the pseudo-signal
3000  handler.
3001
3002  Things are set up so that the handler "returns to" pseudo_sigreturn(),
3003  which will restore the thread's context.
3004
3005  If the handler invokes code that throws (or otherwise never sigreturn()'s
3006  to the context), that's fine.
3007
3008  Actually, check that: throw (and variants) may need to be careful and
3009  pop the tcr's xframe list until it's younger than any frame being
3010  entered.
3011*/
3012
3013int
3014setup_signal_frame(mach_port_t thread,
3015                   void *handler_address,
3016                   int signum,
3017                   int code,
3018                   TCR *tcr,
3019#ifdef X8664
3020                   x86_thread_state64_t *ts
3021#else
3022                   x86_thread_state32_t *ts
3023#endif
3024                   )
3025{
3026#ifdef X8664
3027  x86_thread_state64_t new_ts;
3028#else
3029  x86_thread_state32_t new_ts;
3030#endif
3031  ExceptionInformation *pseudosigcontext;
3032  int  old_valence = tcr->valence;
3033  natural stackp, *stackpp;
3034  siginfo_t *info;
3035
3036#ifdef DEBUG_MACH_EXCEPTIONS
3037  fprintf(dbgout,"Setting up exception handling for 0x%x\n", tcr);
3038#endif
3039  pseudosigcontext = create_thread_context_frame(thread, &stackp, &info, tcr,  ts);
3040  bzero(info, sizeof(*info));
3041  info->si_code = code;
3042  info->si_addr = (void *)(UC_MCONTEXT(pseudosigcontext)->__es.__faultvaddr);
3043  info->si_signo = signum;
3044  pseudosigcontext->uc_onstack = 0;
3045  pseudosigcontext->uc_sigmask = (sigset_t) 0;
3046  pseudosigcontext->uc_stack.ss_sp = 0;
3047  pseudosigcontext->uc_stack.ss_size = 0;
3048  pseudosigcontext->uc_stack.ss_flags = 0;
3049  pseudosigcontext->uc_link = NULL;
3050  pseudosigcontext->uc_mcsize = sizeof(*UC_MCONTEXT(pseudosigcontext));
3051  tcr->pending_exception_context = pseudosigcontext;
3052  tcr->valence = TCR_STATE_EXCEPTION_WAIT;
3053 
3054
3055  /*
3056     It seems like we've created a  sigcontext on the thread's
3057     stack.  Set things up so that we call the handler (with appropriate
3058     args) when the thread's resumed.
3059  */
3060
3061#ifdef X8664
3062  new_ts.__rip = (natural) handler_address;
3063  stackpp = (natural *)stackp;
3064  *--stackpp = (natural)pseudo_sigreturn;
3065  stackp = (natural)stackpp;
3066  new_ts.__rdi = signum;
3067  new_ts.__rsi = (natural)info;
3068  new_ts.__rdx = (natural)pseudosigcontext;
3069  new_ts.__rcx = (natural)tcr;
3070  new_ts.__r8 = (natural)old_valence;
3071  new_ts.__rsp = stackp;
3072  new_ts.__rflags = ts->__rflags;
3073#else
3074#define USER_CS 0x17
3075#define USER_DS 0x1f
3076  bzero(&new_ts, sizeof(new_ts));
3077  new_ts.__cs = ts->__cs;
3078  new_ts.__ss = ts->__ss;
3079  new_ts.__ds = ts->__ds;
3080  new_ts.__es = ts->__es;
3081  new_ts.__fs = ts->__fs;
3082  new_ts.__gs = ts->__gs;
3083
3084  new_ts.__eip = (natural)handler_address;
3085  stackpp = (natural *)stackp;
3086  *--stackpp = 0;               /* alignment */
3087  *--stackpp = 0;
3088  *--stackpp = 0;
3089  *--stackpp = (natural)old_valence;
3090  *--stackpp = (natural)tcr;
3091  *--stackpp = (natural)pseudosigcontext;
3092  *--stackpp = (natural)info;
3093  *--stackpp = (natural)signum;
3094  *--stackpp = (natural)pseudo_sigreturn;
3095  stackp = (natural)stackpp;
3096  new_ts.__esp = stackp;
3097  new_ts.__eflags = ts->__eflags;
3098#endif
3099
3100#ifdef X8664
3101  thread_set_state(thread,
3102                   x86_THREAD_STATE64,
3103                   (thread_state_t)&new_ts,
3104                   x86_THREAD_STATE64_COUNT);
3105#else
3106  thread_set_state(thread, 
3107                   x86_THREAD_STATE32,
3108                   (thread_state_t)&new_ts,
3109                   x86_THREAD_STATE32_COUNT);
3110#endif
3111#ifdef DEBUG_MACH_EXCEPTIONS
3112  fprintf(dbgout,"Set up exception context for 0x%x at 0x%x\n", tcr, tcr->pending_exception_context);
3113#endif
3114  return 0;
3115}
3116
3117
3118
3119
3120
3121
3122/*
3123  This function runs in the exception handling thread.  It's
3124  called (by this precise name) from the library function "exc_server()"
3125  when the thread's exception ports are set up.  (exc_server() is called
3126  via mach_msg_server(), which is a function that waits for and dispatches
3127  on exception messages from the Mach kernel.)
3128
3129  This checks to see if the exception was caused by a pseudo_sigreturn()
3130  UUO; if so, it arranges for the thread to have its state restored
3131  from the specified context.
3132
3133  Otherwise, it tries to map the exception to a signal number and
3134  arranges that the thread run a "pseudo signal handler" to handle
3135  the exception.
3136
3137  Some exceptions could and should be handled here directly.
3138*/
3139
3140/* We need the thread's state earlier on x86_64 than we did on PPC;
3141   the PC won't fit in code_vector[1].  We shouldn't try to get it
3142   lazily (via catch_exception_raise_state()); until we own the
3143   exception lock, we shouldn't have it in userspace (since a GCing
3144   thread wouldn't know that we had our hands on it.)
3145*/
3146
3147#ifdef X8664
3148#define ts_pc(t) t.__rip
3149#else
3150#define ts_pc(t) t.__eip
3151#endif
3152
3153
3154#define DARWIN_EXCEPTION_HANDLER signal_handler
3155
3156
3157kern_return_t
3158catch_exception_raise(mach_port_t exception_port,
3159                      mach_port_t thread,
3160                      mach_port_t task, 
3161                      exception_type_t exception,
3162                      exception_data_t code_vector,
3163                      mach_msg_type_number_t code_count)
3164{
3165  int signum = 0, code = *code_vector;
3166  TCR *tcr = TCR_FROM_EXCEPTION_PORT(exception_port);
3167  kern_return_t kret, call_kret;
3168#ifdef X8664
3169  x86_thread_state64_t ts;
3170#else
3171  x86_thread_state32_t ts;
3172#endif
3173  mach_msg_type_number_t thread_state_count;
3174
3175
3176
3177
3178#ifdef DEBUG_MACH_EXCEPTIONS
3179  fprintf(dbgout, "obtaining Mach exception lock in exception thread\n");
3180#endif
3181
3182
3183  if (1) {
3184#ifdef X8664
3185    do {
3186      thread_state_count = x86_THREAD_STATE64_COUNT;
3187      call_kret = thread_get_state(thread,
3188                                   x86_THREAD_STATE64,
3189                                   (thread_state_t)&ts,
3190                                   &thread_state_count);
3191    } while (call_kret == KERN_ABORTED);
3192  MACH_CHECK_ERROR("getting thread state",call_kret);
3193#else
3194    thread_state_count = x86_THREAD_STATE32_COUNT;
3195    call_kret = thread_get_state(thread,
3196                                 x86_THREAD_STATE32,
3197                                 (thread_state_t)&ts,
3198                                 &thread_state_count);
3199    MACH_CHECK_ERROR("getting thread state",call_kret);
3200#endif
3201    if (tcr->flags & (1<<TCR_FLAG_BIT_PENDING_EXCEPTION)) {
3202      CLR_TCR_FLAG(tcr,TCR_FLAG_BIT_PENDING_EXCEPTION);
3203    } 
3204    if ((code == EXC_I386_GPFLT) &&
3205        ((natural)(ts_pc(ts)) == (natural)pseudo_sigreturn)) {
3206      kret = do_pseudo_sigreturn(thread, tcr);
3207#if 0
3208      fprintf(dbgout, "Exception return in 0x%x\n",tcr);
3209#endif
3210    } else if (tcr->flags & (1<<TCR_FLAG_BIT_PROPAGATE_EXCEPTION)) {
3211      CLR_TCR_FLAG(tcr,TCR_FLAG_BIT_PROPAGATE_EXCEPTION);
3212      kret = 17;
3213    } else {
3214      switch (exception) {
3215      case EXC_BAD_ACCESS:
3216        if (code == EXC_I386_GPFLT) {
3217          signum = SIGSEGV;
3218        } else {
3219          signum = SIGBUS;
3220        }
3221        break;
3222       
3223      case EXC_BAD_INSTRUCTION:
3224        if (code == EXC_I386_GPFLT) {
3225          signum = SIGSEGV;
3226        } else {
3227          signum = SIGILL;
3228        }
3229        break;
3230         
3231      case EXC_SOFTWARE:
3232        signum = SIGILL;
3233        break;
3234       
3235      case EXC_ARITHMETIC:
3236        signum = SIGFPE;
3237        break;
3238       
3239      default:
3240        break;
3241      }
3242      if (signum) {
3243        kret = setup_signal_frame(thread,
3244                                  (void *)DARWIN_EXCEPTION_HANDLER,
3245                                  signum,
3246                                  code,
3247                                  tcr, 
3248                                  &ts);
3249#if 0
3250        fprintf(dbgout, "Setup pseudosignal handling in 0x%x\n",tcr);
3251#endif
3252       
3253      } else {
3254        kret = 17;
3255      }
3256    }
3257  }
3258  return kret;
3259}
3260
3261
3262
3263
3264static mach_port_t mach_exception_thread = (mach_port_t)0;
3265
3266
3267/*
3268  The initial function for an exception-handling thread.
3269*/
3270
3271void *
3272exception_handler_proc(void *arg)
3273{
3274  extern boolean_t exc_server();
3275  mach_port_t p = TCR_TO_EXCEPTION_PORT(arg);
3276
3277  mach_exception_thread = pthread_mach_thread_np(pthread_self());
3278  mach_msg_server(exc_server, 256, p, 0);
3279  /* Should never return. */
3280  abort();
3281}
3282
3283
3284
3285void
3286mach_exception_thread_shutdown()
3287{
3288  kern_return_t kret;
3289
3290  fprintf(dbgout, "terminating Mach exception thread, 'cause exit can't\n");
3291  kret = thread_terminate(mach_exception_thread);
3292  if (kret != KERN_SUCCESS) {
3293    fprintf(dbgout, "Couldn't terminate exception thread, kret = %d\n",kret);
3294  }
3295}
3296
3297
3298mach_port_t
3299mach_exception_port_set()
3300{
3301  static mach_port_t __exception_port_set = MACH_PORT_NULL;
3302  kern_return_t kret; 
3303  if (__exception_port_set == MACH_PORT_NULL) {
3304
3305    kret = mach_port_allocate(mach_task_self(),
3306                              MACH_PORT_RIGHT_PORT_SET,
3307                              &__exception_port_set);
3308    MACH_CHECK_ERROR("allocating thread exception_ports",kret);
3309    create_system_thread(0,
3310                         NULL,
3311                         exception_handler_proc, 
3312                         (void *)((natural)__exception_port_set));
3313  }
3314  return __exception_port_set;
3315}
3316
3317/*
3318  Setup a new thread to handle those exceptions specified by
3319  the mask "which".  This involves creating a special Mach
3320  message port, telling the Mach kernel to send exception
3321  messages for the calling thread to that port, and setting
3322  up a handler thread which listens for and responds to
3323  those messages.
3324
3325*/
3326
3327/*
3328  Establish the lisp thread's TCR as its exception port, and determine
3329  whether any other ports have been established by foreign code for
3330  exceptions that lisp cares about.
3331
3332  If this happens at all, it should happen on return from foreign
3333  code and on entry to lisp code via a callback.
3334
3335  This is a lot of trouble (and overhead) to support Java, or other
3336  embeddable systems that clobber their caller's thread exception ports.
3337 
3338*/
3339kern_return_t
3340tcr_establish_exception_port(TCR *tcr, mach_port_t thread)
3341{
3342  kern_return_t kret;
3343  MACH_foreign_exception_state *fxs = (MACH_foreign_exception_state *)tcr->native_thread_info;
3344  int i;
3345  unsigned n = NUM_LISP_EXCEPTIONS_HANDLED;
3346  mach_port_t lisp_port = TCR_TO_EXCEPTION_PORT(tcr), foreign_port;
3347  exception_mask_t mask = 0;
3348
3349  kret = thread_swap_exception_ports(thread,
3350                                     LISP_EXCEPTIONS_HANDLED_MASK,
3351                                     lisp_port,
3352                                     EXCEPTION_DEFAULT,
3353                                     THREAD_STATE_NONE,
3354                                     fxs->masks,
3355                                     &n,
3356                                     fxs->ports,
3357                                     fxs->behaviors,
3358                                     fxs->flavors);
3359  if (kret == KERN_SUCCESS) {
3360    fxs->foreign_exception_port_count = n;
3361    for (i = 0; i < n; i ++) {
3362      foreign_port = fxs->ports[i];
3363
3364      if ((foreign_port != lisp_port) &&
3365          (foreign_port != MACH_PORT_NULL)) {
3366        mask |= fxs->masks[i];
3367      }
3368    }
3369    tcr->foreign_exception_status = (int) mask;
3370  }
3371  return kret;
3372}
3373
3374kern_return_t
3375tcr_establish_lisp_exception_port(TCR *tcr)
3376{
3377  return tcr_establish_exception_port(tcr, (mach_port_t)((natural)tcr->native_thread_id));
3378}
3379
3380/*
3381  Do this when calling out to or returning from foreign code, if
3382  any conflicting foreign exception ports were established when we
3383  last entered lisp code.
3384*/
3385kern_return_t
3386restore_foreign_exception_ports(TCR *tcr)
3387{
3388  exception_mask_t m = (exception_mask_t) tcr->foreign_exception_status;
3389 
3390  if (m) {
3391    MACH_foreign_exception_state *fxs  = 
3392      (MACH_foreign_exception_state *) tcr->native_thread_info;
3393    int i, n = fxs->foreign_exception_port_count;
3394    exception_mask_t tm;
3395
3396    for (i = 0; i < n; i++) {
3397      if ((tm = fxs->masks[i]) & m) {
3398        thread_set_exception_ports((mach_port_t)((natural)tcr->native_thread_id),
3399                                   tm,
3400                                   fxs->ports[i],
3401                                   fxs->behaviors[i],
3402                                   fxs->flavors[i]);
3403      }
3404    }
3405  }
3406}
3407                                   
3408
3409/*
3410  This assumes that a Mach port (to be used as the thread's exception port) whose
3411  "name" matches the TCR's 32-bit address has already been allocated.
3412*/
3413
3414kern_return_t
3415setup_mach_exception_handling(TCR *tcr)
3416{
3417  mach_port_t
3418    thread_exception_port = TCR_TO_EXCEPTION_PORT(tcr),
3419    task_self = mach_task_self();
3420  kern_return_t kret;
3421
3422  kret = mach_port_insert_right(task_self,
3423                                thread_exception_port,
3424                                thread_exception_port,
3425                                MACH_MSG_TYPE_MAKE_SEND);
3426  MACH_CHECK_ERROR("adding send right to exception_port",kret);
3427
3428  kret = tcr_establish_exception_port(tcr, (mach_port_t)((natural) tcr->native_thread_id));
3429  if (kret == KERN_SUCCESS) {
3430    mach_port_t exception_port_set = mach_exception_port_set();
3431
3432    kret = mach_port_move_member(task_self,
3433                                 thread_exception_port,
3434                                 exception_port_set);
3435  }
3436  return kret;
3437}
3438
3439void
3440darwin_exception_init(TCR *tcr)
3441{
3442  void tcr_monitor_exception_handling(TCR*, Boolean);
3443  kern_return_t kret;
3444  MACH_foreign_exception_state *fxs = 
3445    calloc(1, sizeof(MACH_foreign_exception_state));
3446 
3447  tcr->native_thread_info = (void *) fxs;
3448
3449  if ((kret = setup_mach_exception_handling(tcr))
3450      != KERN_SUCCESS) {
3451    fprintf(dbgout, "Couldn't setup exception handler - error = %d\n", kret);
3452    terminate_lisp();
3453  }
3454  lisp_global(LISP_EXIT_HOOK) = (LispObj) restore_foreign_exception_ports;
3455  lisp_global(LISP_RETURN_HOOK) = (LispObj) tcr_establish_lisp_exception_port;
3456}
3457
3458/*
3459  The tcr is the "name" of the corresponding thread's exception port.
3460  Destroying the port should remove it from all port sets of which it's
3461  a member (notably, the exception port set.)
3462*/
3463void
3464darwin_exception_cleanup(TCR *tcr)
3465{
3466  void *fxs = tcr->native_thread_info;
3467  extern Boolean use_mach_exception_handling;
3468
3469  if (fxs) {
3470    tcr->native_thread_info = NULL;
3471    free(fxs);
3472  }
3473  if (use_mach_exception_handling) {
3474    mach_port_deallocate(mach_task_self(),TCR_TO_EXCEPTION_PORT(tcr));
3475    mach_port_destroy(mach_task_self(),TCR_TO_EXCEPTION_PORT(tcr));
3476  }
3477}
3478
3479
3480Boolean
3481suspend_mach_thread(mach_port_t mach_thread)
3482{
3483  kern_return_t status;
3484  Boolean aborted = false;
3485 
3486  do {
3487    aborted = false;
3488    status = thread_suspend(mach_thread);
3489    if (status == KERN_SUCCESS) {
3490      status = thread_abort_safely(mach_thread);
3491      if (status == KERN_SUCCESS) {
3492        aborted = true;
3493      } else {
3494        fprintf(dbgout, "abort failed on thread = 0x%x\n",mach_thread);
3495        thread_resume(mach_thread);
3496      }
3497    } else {
3498      return false;
3499    }
3500  } while (! aborted);
3501  return true;
3502}
3503
3504/*
3505  Only do this if pthread_kill indicated that the pthread isn't
3506  listening to signals anymore, as can happen as soon as pthread_exit()
3507  is called on Darwin.  The thread could still call out to lisp as it
3508  is exiting, so we need another way to suspend it in this case.
3509*/
3510Boolean
3511mach_suspend_tcr(TCR *tcr)
3512{
3513  mach_port_t mach_thread = (mach_port_t)((natural)( tcr->native_thread_id));
3514  ExceptionInformation *pseudosigcontext;
3515  Boolean result = false;
3516 
3517  result = suspend_mach_thread(mach_thread);
3518  if (result) {
3519    mach_msg_type_number_t thread_state_count;
3520#ifdef X8664
3521    x86_thread_state64_t ts;
3522    thread_state_count = x86_THREAD_STATE64_COUNT;
3523    thread_get_state(mach_thread,
3524                     x86_THREAD_STATE64,
3525                     (thread_state_t)&ts,
3526                     &thread_state_count);
3527#else
3528    x86_thread_state32_t ts;
3529    thread_state_count = x86_THREAD_STATE_COUNT;
3530    thread_get_state(mach_thread,
3531                     x86_THREAD_STATE,
3532                     (thread_state_t)&ts,
3533                     &thread_state_count);
3534#endif
3535
3536    pseudosigcontext = create_thread_context_frame(mach_thread, NULL, NULL,tcr, &ts);
3537    pseudosigcontext->uc_onstack = 0;
3538    pseudosigcontext->uc_sigmask = (sigset_t) 0;
3539    tcr->suspend_context = pseudosigcontext;
3540  }
3541  return result;
3542}
3543
3544void
3545mach_resume_tcr(TCR *tcr)
3546{
3547  ExceptionInformation *xp;
3548  mach_port_t mach_thread = (mach_port_t)((natural)(tcr->native_thread_id));
3549 
3550  xp = tcr->suspend_context;
3551#ifdef DEBUG_MACH_EXCEPTIONS
3552  fprintf(dbgout, "resuming TCR 0x%x, pending_exception_context = 0x%x\n",
3553          tcr, tcr->pending_exception_context);
3554#endif
3555  tcr->suspend_context = NULL;
3556  restore_mach_thread_state(mach_thread, xp);
3557#ifdef DEBUG_MACH_EXCEPTIONS
3558  fprintf(dbgout, "restored state in TCR 0x%x, pending_exception_context = 0x%x\n",
3559          tcr, tcr->pending_exception_context);
3560#endif
3561  thread_resume(mach_thread);
3562}
3563
3564void
3565fatal_mach_error(char *format, ...)
3566{
3567  va_list args;
3568  char s[512];
3569 
3570
3571  va_start(args, format);
3572  vsnprintf(s, sizeof(s),format, args);
3573  va_end(args);
3574
3575  Fatal("Mach error", s);
3576}
3577
3578
3579
3580
3581#endif
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