source: trunk/source/lisp-kernel/x86-exceptions.c @ 11659

Last change on this file since 11659 was 11659, checked in by gz, 11 years ago

Make print-call-history and backtrace-as-list support a :process argument to get the backtrace of that process without interrupting it.

  • Property svn:eol-style set to native
  • Property svn:keywords set to Author Date Id Revision
File size: 95.6 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  area *vs = tcr->vs_area;
2008  BytePtr current_sp = (BytePtr) current_stack_pointer();
2009
2010  if ((current_sp >= vs->low) &&
2011      (current_sp < vs->high)) {
2012    handle_signal_on_foreign_stack(tcr,
2013                                   suspend_resume_handler,
2014                                   signum,
2015                                   info,
2016                                   context,
2017                                   (LispObj)__builtin_return_address(0)
2018#ifdef DARWIN_GS_HACK
2019                                   ,gs_was_tcr
2020#endif
2021                                   );
2022  } else {
2023    /* If we're not on the value stack, we pretty much have to be on
2024       the C stack.  Just run the handler. */
2025#ifdef DARWIN_GS_HACK
2026    if (gs_was_tcr) {
2027      set_gs_address(tcr);
2028    }
2029#endif
2030    suspend_resume_handler(signum, info, context);
2031  }
2032}
2033
2034
2035#else /* altstack works */
2036void
2037altstack_suspend_resume_handler(int signum, siginfo_t *info, ExceptionInformation  *context)
2038{
2039#ifdef DARWIN_GS_HACK
2040  Boolean gs_was_tcr = ensure_gs_pthread();
2041#endif
2042  TCR* tcr = get_tcr(true);
2043  handle_signal_on_foreign_stack(tcr,
2044                                 suspend_resume_handler,
2045                                 signum,
2046                                 info,
2047                                 context,
2048                                 (LispObj)__builtin_return_address(0)
2049#ifdef DARWIN_GS_HACK
2050                                 ,gs_was_tcr
2051#endif
2052                                 );
2053}
2054#endif
2055#endif
2056
2057
2058/* This should only be called when the tcr_area_lock is held */
2059void
2060empty_tcr_stacks(TCR *tcr)
2061{
2062  if (tcr) {
2063    area *a;
2064
2065    tcr->valence = TCR_STATE_FOREIGN;
2066    a = tcr->vs_area;
2067    if (a) {
2068      a->active = a->high;
2069    }
2070    a = tcr->ts_area;
2071    if (a) {
2072      a->active = a->high;
2073    }
2074    a = tcr->cs_area;
2075    if (a) {
2076      a->active = a->high;
2077    }
2078  }
2079}
2080
2081#ifdef WINDOWS
2082void
2083thread_kill_handler(int signum, siginfo_t *info, ExceptionInformation *xp)
2084{
2085}
2086#else
2087void
2088thread_kill_handler(int signum, siginfo_t *info, ExceptionInformation *xp)
2089{
2090#ifdef DARWIN_GS_HACK
2091  Boolean gs_was_tcr = ensure_gs_pthread();
2092#endif
2093  TCR *tcr = get_tcr(false);
2094  sigset_t mask;
2095
2096  sigemptyset(&mask);
2097
2098  empty_tcr_stacks(tcr);
2099
2100  pthread_sigmask(SIG_SETMASK,&mask,NULL);
2101  pthread_exit(NULL);
2102}
2103#endif
2104
2105#ifndef WINDOWS
2106#ifndef USE_SIGALTSTACK
2107void
2108arbstack_thread_kill_handler(int signum, siginfo_t *info, ExceptionInformation *context)
2109{
2110#ifdef DARWIN_GS_HACK
2111  Boolean gs_was_tcr = ensure_gs_pthread();
2112#endif
2113  TCR *tcr = get_interrupt_tcr(false);
2114  area *vs = tcr->vs_area;
2115  BytePtr current_sp = (BytePtr) current_stack_pointer();
2116
2117  if ((current_sp >= vs->low) &&
2118      (current_sp < vs->high)) {
2119    handle_signal_on_foreign_stack(tcr,
2120                                   thread_kill_handler,
2121                                   signum,
2122                                   info,
2123                                   context,
2124                                   (LispObj)__builtin_return_address(0)
2125#ifdef DARWIN_GS_HACK
2126                                   ,gs_was_tcr
2127#endif
2128                                   );
2129  } else {
2130    /* If we're not on the value stack, we pretty much have to be on
2131       the C stack.  Just run the handler. */
2132#ifdef DARWIN_GS_HACK
2133    if (gs_was_tcr) {
2134      set_gs_address(tcr);
2135    }
2136#endif
2137    thread_kill_handler(signum, info, context);
2138  }
2139}
2140
2141
2142#else
2143void
2144altstack_thread_kill_handler(int signum, siginfo_t *info, ExceptionInformation *context)
2145{
2146#ifdef DARWIN_GS_HACK
2147  Boolean gs_was_tcr = ensure_gs_pthread();
2148#endif
2149  TCR* tcr = get_tcr(true);
2150  handle_signal_on_foreign_stack(tcr,
2151                                 thread_kill_handler,
2152                                 signum,
2153                                 info,
2154                                 context,
2155                                 (LispObj)__builtin_return_address(0)
2156#ifdef DARWIN_GS_HACK
2157                                 ,gs_was_tcr
2158#endif
2159                                 );
2160}
2161#endif
2162#endif
2163
2164#ifdef USE_SIGALTSTACK
2165#define SUSPEND_RESUME_HANDLER altstack_suspend_resume_handler
2166#define THREAD_KILL_HANDLER altstack_thread_kill_handler
2167#else
2168#define SUSPEND_RESUME_HANDLER arbstack_suspend_resume_handler
2169#define THREAD_KILL_HANDLER arbstack_thread_kill_handler
2170#endif
2171
2172#ifdef WINDOWS
2173void
2174thread_signal_setup()
2175{
2176}
2177#else
2178void
2179thread_signal_setup()
2180{
2181  thread_suspend_signal = SIG_SUSPEND_THREAD;
2182  thread_kill_signal = SIG_KILL_THREAD;
2183
2184  install_signal_handler(thread_suspend_signal, (void *)SUSPEND_RESUME_HANDLER);
2185  install_signal_handler(thread_kill_signal, (void *)THREAD_KILL_HANDLER);
2186}
2187#endif
2188
2189void
2190enable_fp_exceptions()
2191{
2192}
2193
2194void
2195exception_init()
2196{
2197  install_pmcl_exception_handlers();
2198}
2199
2200void
2201adjust_exception_pc(ExceptionInformation *xp, int delta)
2202{
2203  xpPC(xp) += delta;
2204}
2205
2206/*
2207  Lower (move toward 0) the "end" of the soft protected area associated
2208  with a by a page, if we can.
2209*/
2210
2211void
2212
2213adjust_soft_protection_limit(area *a)
2214{
2215  char *proposed_new_soft_limit = a->softlimit - 4096;
2216  protected_area_ptr p = a->softprot;
2217 
2218  if (proposed_new_soft_limit >= (p->start+16384)) {
2219    p->end = proposed_new_soft_limit;
2220    p->protsize = p->end-p->start;
2221    a->softlimit = proposed_new_soft_limit;
2222  }
2223  protect_area(p);
2224}
2225
2226void
2227restore_soft_stack_limit(unsigned restore_tsp)
2228{
2229  TCR *tcr = get_tcr(false);
2230  area *a;
2231 
2232  if (restore_tsp) {
2233    a = tcr->ts_area;
2234  } else {
2235    a = tcr->vs_area;
2236  }
2237  adjust_soft_protection_limit(a);
2238}
2239
2240
2241#ifdef USE_SIGALTSTACK
2242void
2243setup_sigaltstack(area *a)
2244{
2245  stack_t stack;
2246  stack.ss_sp = a->low;
2247  a->low += SIGSTKSZ*8;
2248  stack.ss_size = SIGSTKSZ*8;
2249  stack.ss_flags = 0;
2250  mmap(stack.ss_sp,stack.ss_size, PROT_READ|PROT_WRITE|PROT_EXEC,MAP_FIXED|MAP_ANON|MAP_PRIVATE,-1,0);
2251  if (sigaltstack(&stack, NULL) != 0) {
2252    perror("sigaltstack");
2253    exit(-1);
2254  }
2255}
2256#endif
2257
2258extern opcode egc_write_barrier_start, egc_write_barrier_end,
2259  egc_set_hash_key_conditional, egc_set_hash_key_conditional_success_test,
2260  egc_store_node_conditional_success_end,
2261  egc_store_node_conditional_success_test,egc_store_node_conditional,
2262  egc_set_hash_key, egc_gvset, egc_rplacd;
2263
2264/* We use (extremely) rigidly defined instruction sequences for consing,
2265   mostly so that 'pc_luser_xp()' knows what to do if a thread is interrupted
2266   while consing.
2267
2268   Note that we can usually identify which of these instructions is about
2269   to be executed by a stopped thread without comparing all of the bytes
2270   to those at the stopped program counter, but we generally need to
2271   know the sizes of each of these instructions.
2272*/
2273
2274#ifdef X8664
2275opcode load_allocptr_reg_from_tcr_save_allocptr_instruction[] =
2276#ifdef WINDOWS
2277  {0x49,0x8b,0x9b,0xd8,0x00,0x00,0x00}
2278#else
2279  {0x65,0x48,0x8b,0x1c,0x25,0xd8,0x00,0x00,0x00}
2280#endif
2281;
2282opcode compare_allocptr_reg_to_tcr_save_allocbase_instruction[] =
2283#ifdef WINDOWS
2284  {0x49,0x3b,0x9b,0xe0,0x00,0x00,0x00}
2285#else
2286  {0x65,0x48,0x3b,0x1c,0x25,0xe0,0x00,0x00,0x00}
2287#endif
2288
2289;
2290opcode branch_around_alloc_trap_instruction[] =
2291  {0x77,0x02};
2292opcode alloc_trap_instruction[] =
2293  {0xcd,0xc5};
2294opcode clear_tcr_save_allocptr_tag_instruction[] =
2295#ifdef WINDOWS
2296  {0x41,0x80,0xa3,0xd8,0x00,0x00,0x00,0xf0}
2297#else
2298  {0x65,0x80,0x24,0x25,0xd8,0x00,0x00,0x00,0xf0}
2299#endif
2300;
2301opcode set_allocptr_header_instruction[] =
2302  {0x48,0x89,0x43,0xf3};
2303
2304
2305alloc_instruction_id
2306recognize_alloc_instruction(pc program_counter)
2307{
2308  switch(program_counter[0]) {
2309  case 0xcd: return ID_alloc_trap_instruction;
2310  /* 0x7f is jg, which we used to use here instead of ja */
2311  case 0x7f:
2312  case 0x77: return ID_branch_around_alloc_trap_instruction;
2313  case 0x48: return ID_set_allocptr_header_instruction;
2314#ifdef WINDOWS
2315  case 0x41: return ID_clear_tcr_save_allocptr_tag_instruction;
2316  case 0x49:
2317    switch(program_counter[1]) {
2318    case 0x8b: return ID_load_allocptr_reg_from_tcr_save_allocptr_instruction;
2319    case 0x3b: return ID_compare_allocptr_reg_to_tcr_save_allocbase_instruction;
2320    }
2321#else
2322  case 0x65: 
2323    switch(program_counter[1]) {
2324    case 0x80: return ID_clear_tcr_save_allocptr_tag_instruction;
2325    case 0x48:
2326      switch(program_counter[2]) {
2327      case 0x3b: return ID_compare_allocptr_reg_to_tcr_save_allocbase_instruction;
2328      case 0x8b: return ID_load_allocptr_reg_from_tcr_save_allocptr_instruction;
2329      }
2330    }
2331#endif
2332  default: break;
2333  }
2334  return ID_unrecognized_alloc_instruction;
2335}
2336#endif
2337#ifdef X8632
2338#ifdef WIN32_ES_HACK
2339/* Win32 keeps the TCR in %es */
2340#define TCR_SEG_PREFIX 0x26     /* %es: */
2341#else
2342/* Other platfroms use %fs */
2343#define TCR_SEG_PREFIX 0x64     /* %fs: */
2344#endif
2345opcode load_allocptr_reg_from_tcr_save_allocptr_instruction[] =
2346  {TCR_SEG_PREFIX,0x8b,0x0d,0x84,0x00,0x00,0x00};
2347opcode compare_allocptr_reg_to_tcr_save_allocbase_instruction[] =
2348  {TCR_SEG_PREFIX,0x3b,0x0d,0x88,0x00,0x00,0x00};
2349opcode branch_around_alloc_trap_instruction[] =
2350  {0x77,0x02};
2351opcode alloc_trap_instruction[] =
2352  {0xcd,0xc5};
2353opcode clear_tcr_save_allocptr_tag_instruction[] =
2354  {TCR_SEG_PREFIX,0x80,0x25,0x84,0x00,0x00,0x00,0xf8};
2355opcode set_allocptr_header_instruction[] =
2356  {0x0f,0x7e,0x41,0xfa};
2357
2358alloc_instruction_id
2359recognize_alloc_instruction(pc program_counter)
2360{
2361  switch(program_counter[0]) {
2362  case 0xcd: return ID_alloc_trap_instruction;
2363  /* 0x7f is jg, which we used to use here instead of ja */
2364  case 0x7f:
2365  case 0x77: return ID_branch_around_alloc_trap_instruction;
2366  case 0x0f: return ID_set_allocptr_header_instruction;
2367  case TCR_SEG_PREFIX: 
2368    switch(program_counter[1]) {
2369    case 0x80: return ID_clear_tcr_save_allocptr_tag_instruction;
2370    case 0x3b: return ID_compare_allocptr_reg_to_tcr_save_allocbase_instruction;
2371    case 0x8b: return ID_load_allocptr_reg_from_tcr_save_allocptr_instruction;
2372    }
2373  }
2374  return ID_unrecognized_alloc_instruction;
2375}
2376#endif     
2377
2378void
2379pc_luser_xp(ExceptionInformation *xp, TCR *tcr, signed_natural *interrupt_displacement)
2380{
2381  pc program_counter = (pc)xpPC(xp);
2382  int allocptr_tag = fulltag_of((LispObj)(tcr->save_allocptr));
2383
2384  if (allocptr_tag != 0) {
2385    alloc_instruction_id state = recognize_alloc_instruction(program_counter);
2386    signed_natural
2387      disp = (allocptr_tag == fulltag_cons) ?
2388      sizeof(cons) - fulltag_cons :
2389#ifdef X8664
2390      xpGPR(xp,Iimm1);
2391#else
2392      xpGPR(xp,Iimm0);
2393#endif
2394    LispObj new_vector;
2395
2396    if ((state == ID_unrecognized_alloc_instruction) ||
2397        ((state == ID_set_allocptr_header_instruction) &&
2398         (allocptr_tag != fulltag_misc))) {
2399      Bug(xp, "Can't determine state of thread 0x" LISP ", interrupted during memory allocation", tcr);
2400    }
2401    switch(state) {
2402    case ID_set_allocptr_header_instruction:
2403      /* We were consing a vector and we won.  Set the header of the
2404         new vector (in the allocptr register) to the header in %rax
2405         (%mm0 on ia32) and skip over this instruction, then fall into
2406         the next case. */
2407      new_vector = xpGPR(xp,Iallocptr);
2408      deref(new_vector,0) = 
2409#ifdef X8664
2410        xpGPR(xp,Iimm0)
2411#else
2412        xpMMXreg(xp,Imm0)
2413#endif
2414        ;
2415
2416      xpPC(xp) += sizeof(set_allocptr_header_instruction);
2417      /* Fall thru */
2418    case ID_clear_tcr_save_allocptr_tag_instruction:
2419      tcr->save_allocptr = (void *)(((LispObj)tcr->save_allocptr) & ~fulltagmask);
2420      xpPC(xp) += sizeof(clear_tcr_save_allocptr_tag_instruction);
2421      break;
2422    case ID_alloc_trap_instruction:
2423      /* If we're looking at another thread, we're pretty much committed to
2424         taking the trap.  We don't want the allocptr register to be pointing
2425         into the heap, so make it point to (- VOID_ALLOCPTR disp), where 'disp'
2426         was determined above.
2427      */
2428      if (interrupt_displacement == NULL) {
2429        xpGPR(xp,Iallocptr) = VOID_ALLOCPTR - disp;
2430        tcr->save_allocptr = (void *)(VOID_ALLOCPTR - disp);
2431      } else {
2432        /* Back out, and tell the caller how to resume the allocation attempt */
2433        *interrupt_displacement = disp;
2434        xpGPR(xp,Iallocptr) = VOID_ALLOCPTR;
2435        tcr->save_allocptr += disp;
2436        xpPC(xp) -= (sizeof(branch_around_alloc_trap_instruction)+
2437                     sizeof(compare_allocptr_reg_to_tcr_save_allocbase_instruction) +
2438                     sizeof(load_allocptr_reg_from_tcr_save_allocptr_instruction));
2439      }
2440      break;
2441    case ID_branch_around_alloc_trap_instruction:
2442      /* If we'd take the branch - which is a "ja" - around the alloc trap,
2443         we might as well finish the allocation.  Otherwise, back out of the
2444         attempt. */
2445      {
2446        int flags = (int)eflags_register(xp);
2447       
2448        if ((!(flags & (1 << X86_ZERO_FLAG_BIT))) &&
2449            (!(flags & (1 << X86_CARRY_FLAG_BIT)))) {
2450          /* The branch (ja) would have been taken.  Emulate taking it. */
2451          xpPC(xp) += (sizeof(branch_around_alloc_trap_instruction)+
2452                       sizeof(alloc_trap_instruction));
2453          if (allocptr_tag == fulltag_misc) {
2454            /* Slap the header on the new uvector */
2455            new_vector = xpGPR(xp,Iallocptr);
2456            deref(new_vector,0) = xpGPR(xp,Iimm0);
2457            xpPC(xp) += sizeof(set_allocptr_header_instruction);
2458          }
2459          tcr->save_allocptr = (void *)(((LispObj)tcr->save_allocptr) & ~fulltagmask);
2460          xpPC(xp) += sizeof(clear_tcr_save_allocptr_tag_instruction);
2461        } else {
2462          /* Back up */
2463          xpPC(xp) -= (sizeof(compare_allocptr_reg_to_tcr_save_allocbase_instruction) +
2464                       sizeof(load_allocptr_reg_from_tcr_save_allocptr_instruction));
2465          xpGPR(xp,Iallocptr) = VOID_ALLOCPTR;
2466          if (interrupt_displacement) {
2467            *interrupt_displacement = disp;
2468            tcr->save_allocptr += disp;
2469          } else {
2470            tcr->save_allocptr = (void *)(VOID_ALLOCPTR-disp);
2471          }
2472        }
2473      }
2474      break;
2475    case ID_compare_allocptr_reg_to_tcr_save_allocbase_instruction:
2476      xpGPR(xp,Iallocptr) = VOID_ALLOCPTR;
2477      xpPC(xp) -= sizeof(load_allocptr_reg_from_tcr_save_allocptr_instruction);
2478      /* Fall through */
2479    case ID_load_allocptr_reg_from_tcr_save_allocptr_instruction:
2480      if (interrupt_displacement) {
2481        tcr->save_allocptr += disp;
2482        *interrupt_displacement = disp;
2483      } else {
2484        tcr->save_allocptr = (void *)(VOID_ALLOCPTR-disp);
2485      }
2486      break;
2487    default: 
2488      break;
2489    }
2490    return;
2491  }
2492  if ((program_counter >= &egc_write_barrier_start) &&
2493      (program_counter < &egc_write_barrier_end)) {
2494    LispObj *ea = 0, val, root = 0;
2495    bitvector refbits = (bitvector)(lisp_global(REFBITS));
2496    Boolean need_store = true, need_check_memo = true, need_memoize_root = false;
2497
2498    if (program_counter >= &egc_set_hash_key_conditional) {
2499      if ((program_counter < &egc_set_hash_key_conditional_success_test) ||
2500          ((program_counter == &egc_set_hash_key_conditional_success_test) &&
2501           !(eflags_register(xp) & (1 << X86_ZERO_FLAG_BIT)))) {
2502        /* Back up the PC, try again */
2503        xpPC(xp) = (LispObj) &egc_set_hash_key_conditional;
2504        return;
2505      }
2506      /* The conditional store succeeded.  Set the refbit, return to ra0 */
2507      val = xpGPR(xp,Iarg_z);
2508#ifdef X8664
2509      root = xpGPR(xp,Iarg_x);
2510      ea = (LispObj*)(root + (unbox_fixnum((signed_natural) xpGPR(xp,Itemp0))));
2511#else
2512      root = xpGPR(xp,Itemp1);
2513      ea = (LispObj *)(root + misc_data_offset + xpGPR(xp,Itemp0));
2514#endif
2515      need_memoize_root = true;
2516      need_store = false;
2517      xpGPR(xp,Iarg_z) = t_value;
2518    } else if (program_counter >= &egc_store_node_conditional) {
2519      if ((program_counter < &egc_store_node_conditional_success_test) ||
2520          ((program_counter == &egc_store_node_conditional_success_test) &&
2521           !(eflags_register(xp) & (1 << X86_ZERO_FLAG_BIT)))) {
2522        /* Back up the PC, try again */
2523        xpPC(xp) = (LispObj) &egc_store_node_conditional;
2524        return;
2525      }
2526      if (program_counter >= &egc_store_node_conditional_success_end) {
2527        return;
2528      }
2529
2530      /* The conditional store succeeded.  Set the refbit, return to ra0 */
2531      val = xpGPR(xp,Iarg_z);
2532#ifdef X8664
2533      ea = (LispObj*)(xpGPR(xp,Iarg_x) + (unbox_fixnum((signed_natural)
2534                                                       xpGPR(xp,Itemp0))));
2535#else
2536      ea = (LispObj *)(misc_data_offset + xpGPR(xp,Itemp1) + xpGPR(xp,Itemp0));
2537#endif
2538      xpGPR(xp,Iarg_z) = t_value;
2539      need_store = false;
2540    } else if (program_counter >= &egc_set_hash_key) {
2541#ifdef X8664
2542      root = xpGPR(xp,Iarg_x);
2543#else
2544      root = xpGPR(xp,Itemp0);
2545#endif
2546      ea = (LispObj *) (root+xpGPR(xp,Iarg_y)+misc_data_offset);
2547      val = xpGPR(xp,Iarg_z);
2548      need_memoize_root = true;
2549    } else if (program_counter >= &egc_gvset) {
2550#ifdef X8664
2551      ea = (LispObj *) (xpGPR(xp,Iarg_x)+xpGPR(xp,Iarg_y)+misc_data_offset);
2552#else
2553      ea = (LispObj *) (xpGPR(xp,Itemp0)+xpGPR(xp,Iarg_y)+misc_data_offset);
2554#endif
2555      val = xpGPR(xp,Iarg_z);
2556    } else if (program_counter >= &egc_rplacd) {
2557      ea = (LispObj *) untag(xpGPR(xp,Iarg_y));
2558      val = xpGPR(xp,Iarg_z);
2559    } else {                      /* egc_rplaca */
2560      ea =  ((LispObj *) untag(xpGPR(xp,Iarg_y)))+1;
2561      val = xpGPR(xp,Iarg_z);
2562    }
2563    if (need_store) {
2564      *ea = val;
2565    }
2566    if (need_check_memo) {
2567      natural  bitnumber = area_dnode(ea, lisp_global(HEAP_START));
2568      if ((bitnumber < lisp_global(OLDSPACE_DNODE_COUNT)) &&
2569          ((LispObj)ea < val)) {
2570        atomic_set_bit(refbits, bitnumber);
2571        if (need_memoize_root) {
2572          bitnumber = area_dnode(root, lisp_global(HEAP_START));
2573          atomic_set_bit(refbits, bitnumber);
2574        }
2575      }
2576    }
2577    {
2578      /* These subprimitives are called via CALL/RET; need
2579         to pop the return address off the stack and set
2580         the PC there. */
2581      LispObj *sp = (LispObj *)xpGPR(xp,Isp), ra = *sp++;
2582      xpPC(xp) = ra;
2583      xpGPR(xp,Isp)=(LispObj)sp;
2584    }
2585    return;
2586  }
2587}
2588
2589
2590void
2591normalize_tcr(ExceptionInformation *xp, TCR *tcr, Boolean is_other_tcr)
2592{
2593  void *cur_allocptr = (void *)(tcr->save_allocptr);
2594  LispObj lisprsp;
2595  area *a;
2596
2597  if (xp) {
2598    if (is_other_tcr) {
2599      pc_luser_xp(xp, tcr, NULL);
2600    }
2601    a = tcr->vs_area;
2602    lisprsp = xpGPR(xp, Isp);
2603    if (((BytePtr)lisprsp >= a->low) &&
2604        ((BytePtr)lisprsp < a->high)) {
2605      a->active = (BytePtr)lisprsp;
2606    } else {
2607      a->active = (BytePtr) tcr->save_vsp;
2608    }
2609    a = tcr->ts_area;
2610    a->active = (BytePtr) tcr->save_tsp;
2611  } else {
2612    /* In ff-call; get area active pointers from tcr */
2613    tcr->vs_area->active = (BytePtr) tcr->save_vsp;
2614    tcr->ts_area->active = (BytePtr) tcr->save_tsp;
2615  }
2616  if (cur_allocptr) {
2617    update_bytes_allocated(tcr, cur_allocptr);
2618  }
2619  tcr->save_allocbase = (void *)VOID_ALLOCPTR;
2620  if (fulltag_of((LispObj)(tcr->save_allocptr)) == 0) {
2621    tcr->save_allocptr = (void *)VOID_ALLOCPTR;
2622  }
2623}
2624
2625
2626/* Suspend and "normalize" other tcrs, then call a gc-like function
2627   in that context.  Resume the other tcrs, then return what the
2628   function returned */
2629
2630TCR *gc_tcr = NULL;
2631
2632
2633signed_natural
2634gc_like_from_xp(ExceptionInformation *xp, 
2635                signed_natural(*fun)(TCR *, signed_natural), 
2636                signed_natural param)
2637{
2638  TCR *tcr = get_tcr(false), *other_tcr;
2639  int result;
2640  signed_natural inhibit;
2641
2642  suspend_other_threads(true);
2643  inhibit = (signed_natural)(lisp_global(GC_INHIBIT_COUNT));
2644  if (inhibit != 0) {
2645    if (inhibit > 0) {
2646      lisp_global(GC_INHIBIT_COUNT) = (LispObj)(-inhibit);
2647    }
2648    resume_other_threads(true);
2649    gc_deferred++;
2650    return 0;
2651  }
2652  gc_deferred = 0;
2653
2654  gc_tcr = tcr;
2655
2656  /* This is generally necessary if the current thread invoked the GC
2657     via an alloc trap, and harmless if the GC was invoked via a GC
2658     trap.  (It's necessary in the first case because the "allocptr"
2659     register - %rbx - may be pointing into the middle of something
2660     below tcr->save_allocbase, and we wouldn't want the GC to see
2661     that bogus pointer.) */
2662  xpGPR(xp, Iallocptr) = VOID_ALLOCPTR; 
2663
2664  normalize_tcr(xp, tcr, false);
2665
2666
2667  for (other_tcr = tcr->next; other_tcr != tcr; other_tcr = other_tcr->next) {
2668    if (other_tcr->pending_exception_context) {
2669      other_tcr->gc_context = other_tcr->pending_exception_context;
2670    } else if (other_tcr->valence == TCR_STATE_LISP) {
2671      other_tcr->gc_context = other_tcr->suspend_context;
2672    } else {
2673      /* no pending exception, didn't suspend in lisp state:
2674         must have executed a synchronous ff-call.
2675      */
2676      other_tcr->gc_context = NULL;
2677    }
2678    normalize_tcr(other_tcr->gc_context, other_tcr, true);
2679  }
2680   
2681
2682
2683  result = fun(tcr, param);
2684
2685  other_tcr = tcr;
2686  do {
2687    other_tcr->gc_context = NULL;
2688    other_tcr = other_tcr->next;
2689  } while (other_tcr != tcr);
2690
2691  gc_tcr = NULL;
2692
2693  resume_other_threads(true);
2694
2695  return result;
2696
2697}
2698
2699signed_natural
2700purify_from_xp(ExceptionInformation *xp, signed_natural param)
2701{
2702  return gc_like_from_xp(xp, purify, param);
2703}
2704
2705signed_natural
2706impurify_from_xp(ExceptionInformation *xp, signed_natural param)
2707{
2708  return gc_like_from_xp(xp, impurify, param);
2709}
2710
2711/* Returns #bytes freed by invoking GC */
2712
2713signed_natural
2714gc_from_tcr(TCR *tcr, signed_natural param)
2715{
2716  area *a;
2717  BytePtr oldfree, newfree;
2718  BytePtr oldend, newend;
2719
2720#if 0
2721  fprintf(dbgout, "Start GC  in 0x" LISP "\n", tcr);
2722#endif
2723  a = active_dynamic_area;
2724  oldend = a->high;
2725  oldfree = a->active;
2726  gc(tcr, param);
2727  newfree = a->active;
2728  newend = a->high;
2729#if 0
2730  fprintf(dbgout, "End GC  in 0x" LISP "\n", tcr);
2731#endif
2732  return ((oldfree-newfree)+(newend-oldend));
2733}
2734
2735signed_natural
2736gc_from_xp(ExceptionInformation *xp, signed_natural param)
2737{
2738  signed_natural status = gc_like_from_xp(xp, gc_from_tcr, param);
2739
2740  freeGCptrs();
2741  return status;
2742}
2743
2744#ifdef DARWIN
2745
2746#define TCR_FROM_EXCEPTION_PORT(p) ((TCR *)((natural)p))
2747#define TCR_TO_EXCEPTION_PORT(tcr) ((mach_port_t)((natural)(tcr)))
2748
2749extern void pseudo_sigreturn(void);
2750
2751
2752
2753#define LISP_EXCEPTIONS_HANDLED_MASK \
2754 (EXC_MASK_SOFTWARE | EXC_MASK_BAD_ACCESS | EXC_MASK_BAD_INSTRUCTION | EXC_MASK_ARITHMETIC)
2755
2756/* (logcount LISP_EXCEPTIONS_HANDLED_MASK) */
2757#define NUM_LISP_EXCEPTIONS_HANDLED 4
2758
2759typedef struct {
2760  int foreign_exception_port_count;
2761  exception_mask_t         masks[NUM_LISP_EXCEPTIONS_HANDLED];
2762  mach_port_t              ports[NUM_LISP_EXCEPTIONS_HANDLED];
2763  exception_behavior_t behaviors[NUM_LISP_EXCEPTIONS_HANDLED];
2764  thread_state_flavor_t  flavors[NUM_LISP_EXCEPTIONS_HANDLED];
2765} MACH_foreign_exception_state;
2766
2767
2768
2769
2770/*
2771  Mach's exception mechanism works a little better than its signal
2772  mechanism (and, not incidentally, it gets along with GDB a lot
2773  better.
2774
2775  Initially, we install an exception handler to handle each native
2776  thread's exceptions.  This process involves creating a distinguished
2777  thread which listens for kernel exception messages on a set of
2778  0 or more thread exception ports.  As threads are created, they're
2779  added to that port set; a thread's exception port is destroyed
2780  (and therefore removed from the port set) when the thread exits.
2781
2782  A few exceptions can be handled directly in the handler thread;
2783  others require that we resume the user thread (and that the
2784  exception thread resumes listening for exceptions.)  The user
2785  thread might eventually want to return to the original context
2786  (possibly modified somewhat.)
2787
2788  As it turns out, the simplest way to force the faulting user
2789  thread to handle its own exceptions is to do pretty much what
2790  signal() does: the exception handlng thread sets up a sigcontext
2791  on the user thread's stack and forces the user thread to resume
2792  execution as if a signal handler had been called with that
2793  context as an argument.  We can use a distinguished UUO at a
2794  distinguished address to do something like sigreturn(); that'll
2795  have the effect of resuming the user thread's execution in
2796  the (pseudo-) signal context.
2797
2798  Since:
2799    a) we have miles of code in C and in Lisp that knows how to
2800    deal with Linux sigcontexts
2801    b) Linux sigcontexts contain a little more useful information
2802    (the DAR, DSISR, etc.) than their Darwin counterparts
2803    c) we have to create a sigcontext ourselves when calling out
2804    to the user thread: we aren't really generating a signal, just
2805    leveraging existing signal-handling code.
2806
2807  we create a Linux sigcontext struct.
2808
2809  Simple ?  Hopefully from the outside it is ...
2810
2811  We want the process of passing a thread's own context to it to
2812  appear to be atomic: in particular, we don't want the GC to suspend
2813  a thread that's had an exception but has not yet had its user-level
2814  exception handler called, and we don't want the thread's exception
2815  context to be modified by a GC while the Mach handler thread is
2816  copying it around.  On Linux (and on Jaguar), we avoid this issue
2817  because (a) the kernel sets up the user-level signal handler and
2818  (b) the signal handler blocks signals (including the signal used
2819  by the GC to suspend threads) until tcr->xframe is set up.
2820
2821  The GC and the Mach server thread therefore contend for the lock
2822  "mach_exception_lock".  The Mach server thread holds the lock
2823  when copying exception information between the kernel and the
2824  user thread; the GC holds this lock during most of its execution
2825  (delaying exception processing until it can be done without
2826  GC interference.)
2827
2828*/
2829
2830#ifdef PPC64
2831#define C_REDZONE_LEN           320
2832#define C_STK_ALIGN             32
2833#else
2834#define C_REDZONE_LEN           224
2835#define C_STK_ALIGN             16
2836#endif
2837#define C_PARAMSAVE_LEN         64
2838#define C_LINKAGE_LEN           48
2839
2840#define TRUNC_DOWN(a,b,c)  (((((natural)a)-(b))/(c)) * (c))
2841
2842void
2843fatal_mach_error(char *format, ...);
2844
2845#define MACH_CHECK_ERROR(context,x) if (x != KERN_SUCCESS) {fatal_mach_error("Mach error while %s : %d", context, x);}
2846
2847
2848void
2849restore_mach_thread_state(mach_port_t thread, ExceptionInformation *pseudosigcontext)
2850{
2851  kern_return_t kret;
2852#if WORD_SIZE == 64
2853  MCONTEXT_T mc = UC_MCONTEXT(pseudosigcontext);
2854#else
2855  mcontext_t mc = UC_MCONTEXT(pseudosigcontext);
2856#endif
2857
2858  /* Set the thread's FP state from the pseudosigcontext */
2859#if WORD_SIZE == 64
2860  kret = thread_set_state(thread,
2861                          x86_FLOAT_STATE64,
2862                          (thread_state_t)&(mc->__fs),
2863                          x86_FLOAT_STATE64_COUNT);
2864#else
2865  kret = thread_set_state(thread,
2866                          x86_FLOAT_STATE32,
2867                          (thread_state_t)&(mc->__fs),
2868                          x86_FLOAT_STATE32_COUNT);
2869#endif
2870  MACH_CHECK_ERROR("setting thread FP state", kret);
2871
2872  /* The thread'll be as good as new ... */
2873#if WORD_SIZE == 64
2874  kret = thread_set_state(thread,
2875                          x86_THREAD_STATE64,
2876                          (thread_state_t)&(mc->__ss),
2877                          x86_THREAD_STATE64_COUNT);
2878#else
2879  kret = thread_set_state(thread, 
2880                          x86_THREAD_STATE32,
2881                          (thread_state_t)&(mc->__ss),
2882                          x86_THREAD_STATE32_COUNT);
2883#endif
2884  MACH_CHECK_ERROR("setting thread state", kret);
2885} 
2886
2887/* This code runs in the exception handling thread, in response
2888   to an attempt to execute the UU0 at "pseudo_sigreturn" (e.g.,
2889   in response to a call to pseudo_sigreturn() from the specified
2890   user thread.
2891   Find that context (the user thread's R3 points to it), then
2892   use that context to set the user thread's state.  When this
2893   function's caller returns, the Mach kernel will resume the
2894   user thread.
2895*/
2896
2897kern_return_t
2898do_pseudo_sigreturn(mach_port_t thread, TCR *tcr)
2899{
2900  ExceptionInformation *xp;
2901
2902#ifdef DEBUG_MACH_EXCEPTIONS
2903  fprintf(dbgout, "doing pseudo_sigreturn for 0x%x\n",tcr);
2904#endif
2905  xp = tcr->pending_exception_context;
2906  if (xp) {
2907    tcr->pending_exception_context = NULL;
2908    tcr->valence = TCR_STATE_LISP;
2909    restore_mach_thread_state(thread, xp);
2910    raise_pending_interrupt(tcr);
2911  } else {
2912    Bug(NULL, "no xp here!\n");
2913  }
2914#ifdef DEBUG_MACH_EXCEPTIONS
2915  fprintf(dbgout, "did pseudo_sigreturn for 0x%x\n",tcr);
2916#endif
2917  return KERN_SUCCESS;
2918} 
2919
2920ExceptionInformation *
2921create_thread_context_frame(mach_port_t thread, 
2922                            natural *new_stack_top,
2923                            siginfo_t **info_ptr,
2924                            TCR *tcr,
2925#ifdef X8664
2926                            x86_thread_state64_t *ts
2927#else
2928                            x86_thread_state32_t *ts
2929#endif
2930                            )
2931{
2932  mach_msg_type_number_t thread_state_count;
2933  ExceptionInformation *pseudosigcontext;
2934#ifdef X8664
2935  MCONTEXT_T mc;
2936#else
2937  mcontext_t mc;
2938#endif
2939  natural stackp;
2940
2941#ifdef X8664 
2942  stackp = (LispObj) find_foreign_rsp(ts->__rsp,tcr->cs_area,tcr);
2943  stackp = TRUNC_DOWN(stackp, C_REDZONE_LEN, C_STK_ALIGN);
2944#else
2945  stackp = (LispObj) find_foreign_rsp(ts->__esp, tcr->cs_area, tcr);
2946#endif
2947  stackp = TRUNC_DOWN(stackp, sizeof(siginfo_t), C_STK_ALIGN);
2948  if (info_ptr) {
2949    *info_ptr = (siginfo_t *)stackp;
2950  }
2951  stackp = TRUNC_DOWN(stackp,sizeof(*pseudosigcontext), C_STK_ALIGN);
2952  pseudosigcontext = (ExceptionInformation *) ptr_from_lispobj(stackp);
2953
2954  stackp = TRUNC_DOWN(stackp, sizeof(*mc), C_STK_ALIGN);
2955  mc = (MCONTEXT_T) ptr_from_lispobj(stackp);
2956 
2957  memmove(&(mc->__ss),ts,sizeof(*ts));
2958
2959#ifdef X8664
2960  thread_state_count = x86_FLOAT_STATE64_COUNT;
2961  thread_get_state(thread,
2962                   x86_FLOAT_STATE64,
2963                   (thread_state_t)&(mc->__fs),
2964                   &thread_state_count);
2965
2966  thread_state_count = x86_EXCEPTION_STATE64_COUNT;
2967  thread_get_state(thread,
2968                   x86_EXCEPTION_STATE64,
2969                   (thread_state_t)&(mc->__es),
2970                   &thread_state_count);
2971#else
2972  thread_state_count = x86_FLOAT_STATE32_COUNT;
2973  thread_get_state(thread,
2974                   x86_FLOAT_STATE32,
2975                   (thread_state_t)&(mc->__fs),
2976                   &thread_state_count);
2977
2978  thread_state_count = x86_EXCEPTION_STATE32_COUNT;
2979  thread_get_state(thread,
2980                   x86_EXCEPTION_STATE32,
2981                   (thread_state_t)&(mc->__es),
2982                   &thread_state_count);
2983#endif
2984
2985
2986  UC_MCONTEXT(pseudosigcontext) = mc;
2987  if (new_stack_top) {
2988    *new_stack_top = stackp;
2989  }
2990  return pseudosigcontext;
2991}
2992
2993/*
2994  This code sets up the user thread so that it executes a "pseudo-signal
2995  handler" function when it resumes.  Create a fake ucontext struct
2996  on the thread's stack and pass it as an argument to the pseudo-signal
2997  handler.
2998
2999  Things are set up so that the handler "returns to" pseudo_sigreturn(),
3000  which will restore the thread's context.
3001
3002  If the handler invokes code that throws (or otherwise never sigreturn()'s
3003  to the context), that's fine.
3004
3005  Actually, check that: throw (and variants) may need to be careful and
3006  pop the tcr's xframe list until it's younger than any frame being
3007  entered.
3008*/
3009
3010int
3011setup_signal_frame(mach_port_t thread,
3012                   void *handler_address,
3013                   int signum,
3014                   int code,
3015                   TCR *tcr,
3016#ifdef X8664
3017                   x86_thread_state64_t *ts
3018#else
3019                   x86_thread_state32_t *ts
3020#endif
3021                   )
3022{
3023#ifdef X8664
3024  x86_thread_state64_t new_ts;
3025#else
3026  x86_thread_state32_t new_ts;
3027#endif
3028  ExceptionInformation *pseudosigcontext;
3029  int  old_valence = tcr->valence;
3030  natural stackp, *stackpp;
3031  siginfo_t *info;
3032
3033#ifdef DEBUG_MACH_EXCEPTIONS
3034  fprintf(dbgout,"Setting up exception handling for 0x%x\n", tcr);
3035#endif
3036  pseudosigcontext = create_thread_context_frame(thread, &stackp, &info, tcr,  ts);
3037  bzero(info, sizeof(*info));
3038  info->si_code = code;
3039  info->si_addr = (void *)(UC_MCONTEXT(pseudosigcontext)->__es.__faultvaddr);
3040  info->si_signo = signum;
3041  pseudosigcontext->uc_onstack = 0;
3042  pseudosigcontext->uc_sigmask = (sigset_t) 0;
3043  pseudosigcontext->uc_stack.ss_sp = 0;
3044  pseudosigcontext->uc_stack.ss_size = 0;
3045  pseudosigcontext->uc_stack.ss_flags = 0;
3046  pseudosigcontext->uc_link = NULL;
3047  pseudosigcontext->uc_mcsize = sizeof(*UC_MCONTEXT(pseudosigcontext));
3048  tcr->pending_exception_context = pseudosigcontext;
3049  tcr->valence = TCR_STATE_EXCEPTION_WAIT;
3050 
3051
3052  /*
3053     It seems like we've created a  sigcontext on the thread's
3054     stack.  Set things up so that we call the handler (with appropriate
3055     args) when the thread's resumed.
3056  */
3057
3058#ifdef X8664
3059  new_ts.__rip = (natural) handler_address;
3060  stackpp = (natural *)stackp;
3061  *--stackpp = (natural)pseudo_sigreturn;
3062  stackp = (natural)stackpp;
3063  new_ts.__rdi = signum;
3064  new_ts.__rsi = (natural)info;
3065  new_ts.__rdx = (natural)pseudosigcontext;
3066  new_ts.__rcx = (natural)tcr;
3067  new_ts.__r8 = (natural)old_valence;
3068  new_ts.__rsp = stackp;
3069  new_ts.__rflags = ts->__rflags;
3070#else
3071#define USER_CS 0x17
3072#define USER_DS 0x1f
3073  bzero(&new_ts, sizeof(new_ts));
3074  new_ts.__cs = ts->__cs;
3075  new_ts.__ss = ts->__ss;
3076  new_ts.__ds = ts->__ds;
3077  new_ts.__es = ts->__es;
3078  new_ts.__fs = ts->__fs;
3079  new_ts.__gs = ts->__gs;
3080
3081  new_ts.__eip = (natural)handler_address;
3082  stackpp = (natural *)stackp;
3083  *--stackpp = 0;               /* alignment */
3084  *--stackpp = 0;
3085  *--stackpp = 0;
3086  *--stackpp = (natural)old_valence;
3087  *--stackpp = (natural)tcr;
3088  *--stackpp = (natural)pseudosigcontext;
3089  *--stackpp = (natural)info;
3090  *--stackpp = (natural)signum;
3091  *--stackpp = (natural)pseudo_sigreturn;
3092  stackp = (natural)stackpp;
3093  new_ts.__esp = stackp;
3094  new_ts.__eflags = ts->__eflags;
3095#endif
3096
3097#ifdef X8664
3098  thread_set_state(thread,
3099                   x86_THREAD_STATE64,
3100                   (thread_state_t)&new_ts,
3101                   x86_THREAD_STATE64_COUNT);
3102#else
3103  thread_set_state(thread, 
3104                   x86_THREAD_STATE32,
3105                   (thread_state_t)&new_ts,
3106                   x86_THREAD_STATE32_COUNT);
3107#endif
3108#ifdef DEBUG_MACH_EXCEPTIONS
3109  fprintf(dbgout,"Set up exception context for 0x%x at 0x%x\n", tcr, tcr->pending_exception_context);
3110#endif
3111  return 0;
3112}
3113
3114
3115
3116
3117
3118
3119/*
3120  This function runs in the exception handling thread.  It's
3121  called (by this precise name) from the library function "exc_server()"
3122  when the thread's exception ports are set up.  (exc_server() is called
3123  via mach_msg_server(), which is a function that waits for and dispatches
3124  on exception messages from the Mach kernel.)
3125
3126  This checks to see if the exception was caused by a pseudo_sigreturn()
3127  UUO; if so, it arranges for the thread to have its state restored
3128  from the specified context.
3129
3130  Otherwise, it tries to map the exception to a signal number and
3131  arranges that the thread run a "pseudo signal handler" to handle
3132  the exception.
3133
3134  Some exceptions could and should be handled here directly.
3135*/
3136
3137/* We need the thread's state earlier on x86_64 than we did on PPC;
3138   the PC won't fit in code_vector[1].  We shouldn't try to get it
3139   lazily (via catch_exception_raise_state()); until we own the
3140   exception lock, we shouldn't have it in userspace (since a GCing
3141   thread wouldn't know that we had our hands on it.)
3142*/
3143
3144#ifdef X8664
3145#define ts_pc(t) t.__rip
3146#else
3147#define ts_pc(t) t.__eip
3148#endif
3149
3150
3151#define DARWIN_EXCEPTION_HANDLER signal_handler
3152
3153
3154kern_return_t
3155catch_exception_raise(mach_port_t exception_port,
3156                      mach_port_t thread,
3157                      mach_port_t task, 
3158                      exception_type_t exception,
3159                      exception_data_t code_vector,
3160                      mach_msg_type_number_t code_count)
3161{
3162  int signum = 0, code = *code_vector;
3163  TCR *tcr = TCR_FROM_EXCEPTION_PORT(exception_port);
3164  kern_return_t kret, call_kret;
3165#ifdef X8664
3166  x86_thread_state64_t ts;
3167#else
3168  x86_thread_state32_t ts;
3169#endif
3170  mach_msg_type_number_t thread_state_count;
3171
3172
3173
3174
3175#ifdef DEBUG_MACH_EXCEPTIONS
3176  fprintf(dbgout, "obtaining Mach exception lock in exception thread\n");
3177#endif
3178
3179
3180  if (1) {
3181#ifdef X8664
3182    do {
3183      thread_state_count = x86_THREAD_STATE64_COUNT;
3184      call_kret = thread_get_state(thread,
3185                                   x86_THREAD_STATE64,
3186                                   (thread_state_t)&ts,
3187                                   &thread_state_count);
3188    } while (call_kret == KERN_ABORTED);
3189  MACH_CHECK_ERROR("getting thread state",call_kret);
3190#else
3191    thread_state_count = x86_THREAD_STATE32_COUNT;
3192    call_kret = thread_get_state(thread,
3193                                 x86_THREAD_STATE32,
3194                                 (thread_state_t)&ts,
3195                                 &thread_state_count);
3196    MACH_CHECK_ERROR("getting thread state",call_kret);
3197#endif
3198    if (tcr->flags & (1<<TCR_FLAG_BIT_PENDING_EXCEPTION)) {
3199      CLR_TCR_FLAG(tcr,TCR_FLAG_BIT_PENDING_EXCEPTION);
3200    } 
3201    if ((code == EXC_I386_GPFLT) &&
3202        ((natural)(ts_pc(ts)) == (natural)pseudo_sigreturn)) {
3203      kret = do_pseudo_sigreturn(thread, tcr);
3204#if 0
3205      fprintf(dbgout, "Exception return in 0x%x\n",tcr);
3206#endif
3207    } else if (tcr->flags & (1<<TCR_FLAG_BIT_PROPAGATE_EXCEPTION)) {
3208      CLR_TCR_FLAG(tcr,TCR_FLAG_BIT_PROPAGATE_EXCEPTION);
3209      kret = 17;
3210    } else {
3211      switch (exception) {
3212      case EXC_BAD_ACCESS:
3213        if (code == EXC_I386_GPFLT) {
3214          signum = SIGSEGV;
3215        } else {
3216          signum = SIGBUS;
3217        }
3218        break;
3219       
3220      case EXC_BAD_INSTRUCTION:
3221        if (code == EXC_I386_GPFLT) {
3222          signum = SIGSEGV;
3223        } else {
3224          signum = SIGILL;
3225        }
3226        break;
3227         
3228      case EXC_SOFTWARE:
3229        signum = SIGILL;
3230        break;
3231       
3232      case EXC_ARITHMETIC:
3233        signum = SIGFPE;
3234        break;
3235       
3236      default:
3237        break;
3238      }
3239      if (signum) {
3240        kret = setup_signal_frame(thread,
3241                                  (void *)DARWIN_EXCEPTION_HANDLER,
3242                                  signum,
3243                                  code,
3244                                  tcr, 
3245                                  &ts);
3246#if 0
3247        fprintf(dbgout, "Setup pseudosignal handling in 0x%x\n",tcr);
3248#endif
3249       
3250      } else {
3251        kret = 17;
3252      }
3253    }
3254  }
3255  return kret;
3256}
3257
3258
3259
3260
3261static mach_port_t mach_exception_thread = (mach_port_t)0;
3262
3263
3264/*
3265  The initial function for an exception-handling thread.
3266*/
3267
3268void *
3269exception_handler_proc(void *arg)
3270{
3271  extern boolean_t exc_server();
3272  mach_port_t p = TCR_TO_EXCEPTION_PORT(arg);
3273
3274  mach_exception_thread = pthread_mach_thread_np(pthread_self());
3275  mach_msg_server(exc_server, 256, p, 0);
3276  /* Should never return. */
3277  abort();
3278}
3279
3280
3281
3282void
3283mach_exception_thread_shutdown()
3284{
3285  kern_return_t kret;
3286
3287  fprintf(dbgout, "terminating Mach exception thread, 'cause exit can't\n");
3288  kret = thread_terminate(mach_exception_thread);
3289  if (kret != KERN_SUCCESS) {
3290    fprintf(dbgout, "Couldn't terminate exception thread, kret = %d\n",kret);
3291  }
3292}
3293
3294
3295mach_port_t
3296mach_exception_port_set()
3297{
3298  static mach_port_t __exception_port_set = MACH_PORT_NULL;
3299  kern_return_t kret; 
3300  if (__exception_port_set == MACH_PORT_NULL) {
3301
3302    kret = mach_port_allocate(mach_task_self(),
3303                              MACH_PORT_RIGHT_PORT_SET,
3304                              &__exception_port_set);
3305    MACH_CHECK_ERROR("allocating thread exception_ports",kret);
3306    create_system_thread(0,
3307                         NULL,
3308                         exception_handler_proc, 
3309                         (void *)((natural)__exception_port_set));
3310  }
3311  return __exception_port_set;
3312}
3313
3314/*
3315  Setup a new thread to handle those exceptions specified by
3316  the mask "which".  This involves creating a special Mach
3317  message port, telling the Mach kernel to send exception
3318  messages for the calling thread to that port, and setting
3319  up a handler thread which listens for and responds to
3320  those messages.
3321
3322*/
3323
3324/*
3325  Establish the lisp thread's TCR as its exception port, and determine
3326  whether any other ports have been established by foreign code for
3327  exceptions that lisp cares about.
3328
3329  If this happens at all, it should happen on return from foreign
3330  code and on entry to lisp code via a callback.
3331
3332  This is a lot of trouble (and overhead) to support Java, or other
3333  embeddable systems that clobber their caller's thread exception ports.
3334 
3335*/
3336kern_return_t
3337tcr_establish_exception_port(TCR *tcr, mach_port_t thread)
3338{
3339  kern_return_t kret;
3340  MACH_foreign_exception_state *fxs = (MACH_foreign_exception_state *)tcr->native_thread_info;
3341  int i;
3342  unsigned n = NUM_LISP_EXCEPTIONS_HANDLED;
3343  mach_port_t lisp_port = TCR_TO_EXCEPTION_PORT(tcr), foreign_port;
3344  exception_mask_t mask = 0;
3345
3346  kret = thread_swap_exception_ports(thread,
3347                                     LISP_EXCEPTIONS_HANDLED_MASK,
3348                                     lisp_port,
3349                                     EXCEPTION_DEFAULT,
3350                                     THREAD_STATE_NONE,
3351                                     fxs->masks,
3352                                     &n,
3353                                     fxs->ports,
3354                                     fxs->behaviors,
3355                                     fxs->flavors);
3356  if (kret == KERN_SUCCESS) {
3357    fxs->foreign_exception_port_count = n;
3358    for (i = 0; i < n; i ++) {
3359      foreign_port = fxs->ports[i];
3360
3361      if ((foreign_port != lisp_port) &&
3362          (foreign_port != MACH_PORT_NULL)) {
3363        mask |= fxs->masks[i];
3364      }
3365    }
3366    tcr->foreign_exception_status = (int) mask;
3367  }
3368  return kret;
3369}
3370
3371kern_return_t
3372tcr_establish_lisp_exception_port(TCR *tcr)
3373{
3374  return tcr_establish_exception_port(tcr, (mach_port_t)((natural)tcr->native_thread_id));
3375}
3376
3377/*
3378  Do this when calling out to or returning from foreign code, if
3379  any conflicting foreign exception ports were established when we
3380  last entered lisp code.
3381*/
3382kern_return_t
3383restore_foreign_exception_ports(TCR *tcr)
3384{
3385  exception_mask_t m = (exception_mask_t) tcr->foreign_exception_status;
3386 
3387  if (m) {
3388    MACH_foreign_exception_state *fxs  = 
3389      (MACH_foreign_exception_state *) tcr->native_thread_info;
3390    int i, n = fxs->foreign_exception_port_count;
3391    exception_mask_t tm;
3392
3393    for (i = 0; i < n; i++) {
3394      if ((tm = fxs->masks[i]) & m) {
3395        thread_set_exception_ports((mach_port_t)((natural)tcr->native_thread_id),
3396                                   tm,
3397                                   fxs->ports[i],
3398                                   fxs->behaviors[i],
3399                                   fxs->flavors[i]);
3400      }
3401    }
3402  }
3403}
3404                                   
3405
3406/*
3407  This assumes that a Mach port (to be used as the thread's exception port) whose
3408  "name" matches the TCR's 32-bit address has already been allocated.
3409*/
3410
3411kern_return_t
3412setup_mach_exception_handling(TCR *tcr)
3413{
3414  mach_port_t
3415    thread_exception_port = TCR_TO_EXCEPTION_PORT(tcr),
3416    task_self = mach_task_self();
3417  kern_return_t kret;
3418
3419  kret = mach_port_insert_right(task_self,
3420                                thread_exception_port,
3421                                thread_exception_port,
3422                                MACH_MSG_TYPE_MAKE_SEND);
3423  MACH_CHECK_ERROR("adding send right to exception_port",kret);
3424
3425  kret = tcr_establish_exception_port(tcr, (mach_port_t)((natural) tcr->native_thread_id));
3426  if (kret == KERN_SUCCESS) {
3427    mach_port_t exception_port_set = mach_exception_port_set();
3428
3429    kret = mach_port_move_member(task_self,
3430                                 thread_exception_port,
3431                                 exception_port_set);
3432  }
3433  return kret;
3434}
3435
3436void
3437darwin_exception_init(TCR *tcr)
3438{
3439  void tcr_monitor_exception_handling(TCR*, Boolean);
3440  kern_return_t kret;
3441  MACH_foreign_exception_state *fxs = 
3442    calloc(1, sizeof(MACH_foreign_exception_state));
3443 
3444  tcr->native_thread_info = (void *) fxs;
3445
3446  if ((kret = setup_mach_exception_handling(tcr))
3447      != KERN_SUCCESS) {
3448    fprintf(dbgout, "Couldn't setup exception handler - error = %d\n", kret);
3449    terminate_lisp();
3450  }
3451  lisp_global(LISP_EXIT_HOOK) = (LispObj) restore_foreign_exception_ports;
3452  lisp_global(LISP_RETURN_HOOK) = (LispObj) tcr_establish_lisp_exception_port;
3453}
3454
3455/*
3456  The tcr is the "name" of the corresponding thread's exception port.
3457  Destroying the port should remove it from all port sets of which it's
3458  a member (notably, the exception port set.)
3459*/
3460void
3461darwin_exception_cleanup(TCR *tcr)
3462{
3463  void *fxs = tcr->native_thread_info;
3464  extern Boolean use_mach_exception_handling;
3465
3466  if (fxs) {
3467    tcr->native_thread_info = NULL;
3468    free(fxs);
3469  }
3470  if (use_mach_exception_handling) {
3471    mach_port_deallocate(mach_task_self(),TCR_TO_EXCEPTION_PORT(tcr));
3472    mach_port_destroy(mach_task_self(),TCR_TO_EXCEPTION_PORT(tcr));
3473  }
3474}
3475
3476
3477Boolean
3478suspend_mach_thread(mach_port_t mach_thread)
3479{
3480  kern_return_t status;
3481  Boolean aborted = false;
3482 
3483  do {
3484    aborted = false;
3485    status = thread_suspend(mach_thread);
3486    if (status == KERN_SUCCESS) {
3487      status = thread_abort_safely(mach_thread);
3488      if (status == KERN_SUCCESS) {
3489        aborted = true;
3490      } else {
3491        fprintf(dbgout, "abort failed on thread = 0x%x\n",mach_thread);
3492        thread_resume(mach_thread);
3493      }
3494    } else {
3495      return false;
3496    }
3497  } while (! aborted);
3498  return true;
3499}
3500
3501/*
3502  Only do this if pthread_kill indicated that the pthread isn't
3503  listening to signals anymore, as can happen as soon as pthread_exit()
3504  is called on Darwin.  The thread could still call out to lisp as it
3505  is exiting, so we need another way to suspend it in this case.
3506*/
3507Boolean
3508mach_suspend_tcr(TCR *tcr)
3509{
3510  mach_port_t mach_thread = (mach_port_t)((natural)( tcr->native_thread_id));
3511  ExceptionInformation *pseudosigcontext;
3512  Boolean result = false;
3513 
3514  result = suspend_mach_thread(mach_thread);
3515  if (result) {
3516    mach_msg_type_number_t thread_state_count;
3517#ifdef X8664
3518    x86_thread_state64_t ts;
3519    thread_state_count = x86_THREAD_STATE64_COUNT;
3520    thread_get_state(mach_thread,
3521                     x86_THREAD_STATE64,
3522                     (thread_state_t)&ts,
3523                     &thread_state_count);
3524#else
3525    x86_thread_state32_t ts;
3526    thread_state_count = x86_THREAD_STATE_COUNT;
3527    thread_get_state(mach_thread,
3528                     x86_THREAD_STATE,
3529                     (thread_state_t)&ts,
3530                     &thread_state_count);
3531#endif
3532
3533    pseudosigcontext = create_thread_context_frame(mach_thread, NULL, NULL,tcr, &ts);
3534    pseudosigcontext->uc_onstack = 0;
3535    pseudosigcontext->uc_sigmask = (sigset_t) 0;
3536    tcr->suspend_context = pseudosigcontext;
3537  }
3538  return result;
3539}
3540
3541void
3542mach_resume_tcr(TCR *tcr)
3543{
3544  ExceptionInformation *xp;
3545  mach_port_t mach_thread = (mach_port_t)((natural)(tcr->native_thread_id));
3546 
3547  xp = tcr->suspend_context;
3548#ifdef DEBUG_MACH_EXCEPTIONS
3549  fprintf(dbgout, "resuming TCR 0x%x, pending_exception_context = 0x%x\n",
3550          tcr, tcr->pending_exception_context);
3551#endif
3552  tcr->suspend_context = NULL;
3553  restore_mach_thread_state(mach_thread, xp);
3554#ifdef DEBUG_MACH_EXCEPTIONS
3555  fprintf(dbgout, "restored state in TCR 0x%x, pending_exception_context = 0x%x\n",
3556          tcr, tcr->pending_exception_context);
3557#endif
3558  thread_resume(mach_thread);
3559}
3560
3561void
3562fatal_mach_error(char *format, ...)
3563{
3564  va_list args;
3565  char s[512];
3566 
3567
3568  va_start(args, format);
3569  vsnprintf(s, sizeof(s),format, args);
3570  va_end(args);
3571
3572  Fatal("Mach error", s);
3573}
3574
3575
3576
3577
3578#endif
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