source: trunk/source/lisp-kernel/x86-exceptions.c @ 11551

Last change on this file since 11551 was 11551, checked in by gb, 11 years ago

Not the bug I was looking for either, but un-botch some of the GC-state-saving
changes from a few weeks ago: save_application() is always run with the
EGC off, so make the caller pass an extra arg indicating its state as of
the time we trapped to it. Set G2_THRESHOLD global before writing image,
don't set G1_THRESHOLD twice.

Images built a few weeks ago have EGC off and misconfigured.

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File size: 95.4 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(stderr, "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(stderr, "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 *
1434find_foreign_rsp(LispObj rsp, area *foreign_area, TCR *tcr)
1435{
1436
1437  if (((BytePtr)rsp < foreign_area->low) ||
1438      ((BytePtr)rsp > foreign_area->high)) {
1439    rsp = (LispObj)(tcr->foreign_sp);
1440  }
1441  return (LispObj *) (((rsp-128) & ~15));
1442}
1443
1444#ifdef X8632
1445#ifdef LINUX
1446/* This is here for debugging.  On entry to a signal handler that
1447   receives info and context arguments, the stack should look exactly
1448   like this.  The "pretcode field" of the structure is the address
1449   of code that does an rt_sigreturn syscall, and rt_sigreturn expects
1450   %esp at the time of that syscall to be pointing just past the
1451   pretcode field.
1452   handle_signal_on_foreign_stack() and helpers have to be very
1453   careful to duplicate this "structure" exactly.
1454   Note that on x8664 Linux, rt_sigreturn expects a ucontext to
1455   be on top of the stack (with a siginfo_t underneath it.)
1456   It sort of half-works to do sigreturn via setcontext() on
1457   x8632 Linux, but (a) it may not be available on some distributions
1458   and (b) even a relatively modern version of it uses "fldenv" to
1459   restore FP context, and "fldenv" isn't nearly good enough.
1460*/
1461
1462struct rt_sigframe {
1463        char *pretcode;
1464        int sig;
1465        siginfo_t  *pinfo;
1466        void  *puc;
1467        siginfo_t info;
1468        struct ucontext uc;
1469        struct _fpstate fpstate;
1470        char retcode[8];
1471};
1472struct rt_sigframe *rtsf = 0;
1473
1474#endif
1475#endif
1476
1477#ifdef DARWIN
1478void
1479bogus_signal_handler(int signum, siginfo_t *info, ExceptionInformation *xp)
1480{
1481  if (signum == SIGSYS) {
1482    return;                     /* Leopard lossage */
1483  }
1484}
1485#endif
1486
1487#ifndef WINDOWS
1488/* x8632 Linux requires that the stack-allocated siginfo is nearer
1489   the top of stack than the stack-allocated ucontext.  If other
1490   platforms care, they expect the ucontext to be nearer the top
1491   of stack.
1492*/
1493
1494#if defined(LINUX) && defined(X8632)
1495#define UCONTEXT_ON_TOP_OF_STACK 0
1496#else
1497#define UCONTEXT_ON_TOP_OF_STACK 1
1498#endif
1499void
1500handle_signal_on_foreign_stack(TCR *tcr,
1501                               void *handler, 
1502                               int signum, 
1503                               siginfo_t *info, 
1504                               ExceptionInformation *context,
1505                               LispObj return_address
1506#ifdef DARWIN_GS_HACK
1507                               , Boolean gs_was_tcr
1508#endif
1509                               )
1510{
1511#ifdef LINUX
1512  FPREGS fpregs = NULL;
1513#else
1514  void *fpregs = NULL;
1515#endif
1516#ifdef DARWIN
1517  MCONTEXT_T mcontextp = NULL;
1518#endif
1519  siginfo_t *info_copy = NULL;
1520  ExceptionInformation *xp = NULL;
1521  LispObj *foreign_rsp = find_foreign_rsp(xpGPR(context,Isp), tcr->cs_area, tcr);
1522
1523#ifdef LINUX
1524  foreign_rsp = copy_fpregs(context, foreign_rsp, &fpregs);
1525#endif
1526#ifdef DARWIN
1527  foreign_rsp = copy_darwin_mcontext(UC_MCONTEXT(context), foreign_rsp, &mcontextp);
1528#endif
1529#if UCONTEXT_ON_TOP_OF_STACK
1530  /* copy info first */
1531  foreign_rsp = copy_siginfo(info, foreign_rsp);
1532  info_copy = (siginfo_t *)foreign_rsp;
1533  foreign_rsp = copy_ucontext(context, foreign_rsp, fpregs);
1534  xp = (ExceptionInformation *)foreign_rsp;
1535#else
1536  foreign_rsp = copy_ucontext(context, foreign_rsp, fpregs);
1537  xp = (ExceptionInformation *)foreign_rsp;
1538  foreign_rsp = copy_siginfo(info, foreign_rsp);
1539  info_copy = (siginfo_t *)foreign_rsp;
1540#endif
1541#ifdef DARWIN
1542  UC_MCONTEXT(xp) = mcontextp;
1543#endif
1544  *--foreign_rsp = return_address;
1545#ifdef DARWIN_GS_HACK
1546  if (gs_was_tcr) {
1547    set_gs_address(tcr);
1548  }
1549#endif
1550  switch_to_foreign_stack(foreign_rsp,handler,signum,info_copy,xp);
1551}
1552#endif
1553
1554
1555#ifndef WINDOWS
1556#ifndef USE_SIGALTSTACK
1557void
1558arbstack_signal_handler(int signum, siginfo_t *info, ExceptionInformation *context)
1559{
1560  TCR *tcr = get_interrupt_tcr(false);
1561#if 1
1562  if (tcr->valence != TCR_STATE_LISP) {
1563    FBug(context, "exception in foreign context");
1564  }
1565#endif
1566  {
1567    area *vs = tcr->vs_area;
1568    BytePtr current_sp = (BytePtr) current_stack_pointer();
1569
1570
1571    if ((current_sp >= vs->low) &&
1572        (current_sp < vs->high)) {
1573      handle_signal_on_foreign_stack(tcr,
1574                                     signal_handler,
1575                                     signum,
1576                                     info,
1577                                     context,
1578                                     (LispObj)__builtin_return_address(0)
1579#ifdef DARWIN_GS_HACK
1580                                     , false
1581#endif
1582
1583                                     );
1584    } else {
1585      signal_handler(signum, info, context, tcr, 0);
1586    }
1587  }
1588}
1589
1590#else
1591void
1592altstack_signal_handler(int signum, siginfo_t *info, ExceptionInformation  *context)
1593{
1594  TCR* tcr = get_tcr(true);
1595#if 1
1596  if (tcr->valence != TCR_STATE_LISP) {
1597    FBug(context, "exception in foreign context");
1598  }
1599#endif
1600  handle_signal_on_foreign_stack(tcr,signal_handler,signum,info,context,(LispObj)__builtin_return_address(0)
1601#ifdef DARWIN_GS_HACK
1602                                 , false
1603#endif
1604);
1605}
1606#endif
1607#endif
1608
1609Boolean
1610stack_pointer_on_vstack_p(LispObj stack_pointer, TCR *tcr)
1611{
1612  area *a = tcr->vs_area;
1613 
1614  return (((BytePtr)stack_pointer <= a->high) &&
1615          ((BytePtr)stack_pointer > a->low));
1616}
1617
1618
1619#ifdef WINDOWS
1620extern DWORD restore_windows_context(ExceptionInformation *, TCR *, int);
1621#endif
1622
1623void
1624interrupt_handler (int signum, siginfo_t *info, ExceptionInformation *context)
1625{
1626#ifdef DARWIN_GS_HACK
1627  Boolean gs_was_tcr = ensure_gs_pthread();
1628#endif
1629  TCR *tcr = get_interrupt_tcr(false);
1630  int old_valence = tcr->valence;
1631
1632  if (tcr) {
1633    if ((TCR_INTERRUPT_LEVEL(tcr) < 0) ||
1634        (tcr->valence != TCR_STATE_LISP) ||
1635        (tcr->unwinding != 0) ||
1636        ! stack_pointer_on_vstack_p(xpGPR(context,Isp), tcr) ||
1637#ifdef X8664
1638        ! stack_pointer_on_vstack_p(xpGPR(context,Irbp), tcr)) {
1639#else
1640        ! stack_pointer_on_vstack_p(xpGPR(context,Iebp), tcr)) {
1641#endif
1642      tcr->interrupt_pending = (((natural) 1)<< (nbits_in_word - ((natural)1)));
1643    } else {
1644      LispObj cmain = nrs_CMAIN.vcell;
1645
1646      if ((fulltag_of(cmain) == fulltag_misc) &&
1647          (header_subtag(header_of(cmain)) == subtag_macptr)) {
1648        /*
1649           This thread can (allegedly) take an interrupt now.
1650        */
1651
1652        xframe_list xframe_link;
1653        signed_natural alloc_displacement = 0;
1654        LispObj
1655          *next_tsp = tcr->next_tsp,
1656          *save_tsp = tcr->save_tsp,
1657          *p,
1658          q;
1659        natural old_foreign_exception = tcr->flags & (1 << TCR_FLAG_BIT_FOREIGN_EXCEPTION);
1660
1661        tcr->flags &= ~(1 << TCR_FLAG_BIT_FOREIGN_EXCEPTION);
1662           
1663        if (next_tsp != save_tsp) {
1664          tcr->next_tsp = save_tsp;
1665        } else {
1666          next_tsp = NULL;
1667        }
1668        /* have to do this before allowing interrupts */
1669        pc_luser_xp(context, tcr, &alloc_displacement);
1670        old_valence = prepare_to_wait_for_exception_lock(tcr, context);
1671        wait_for_exception_lock_in_handler(tcr, context, &xframe_link);
1672        handle_exception(signum, info, context, tcr, old_valence);
1673        if (alloc_displacement) {
1674          tcr->save_allocptr -= alloc_displacement;
1675        }
1676        if (next_tsp) {
1677          tcr->next_tsp = next_tsp;
1678          p = next_tsp;
1679          while (p != save_tsp) {
1680            *p++ = 0;
1681          }
1682          q = (LispObj)save_tsp;
1683          *next_tsp = q;
1684        }
1685        tcr->flags |= old_foreign_exception;
1686        unlock_exception_lock_in_handler(tcr);
1687#ifndef WINDOWS
1688        exit_signal_handler(tcr, old_valence);
1689#endif
1690      }
1691    }
1692  }
1693#ifdef DARWIN_GS_HACK
1694  if (gs_was_tcr) {
1695    set_gs_address(tcr);
1696  }
1697#endif
1698#ifdef WINDOWS
1699  restore_windows_context(context,tcr,old_valence);
1700#else
1701  SIGRETURN(context);
1702#endif
1703}
1704
1705
1706#ifndef WINDOWS
1707#ifndef USE_SIGALTSTACK
1708void
1709arbstack_interrupt_handler (int signum, siginfo_t *info, ExceptionInformation *context)
1710{
1711#ifdef DARWIN_GS_HACK
1712  Boolean gs_was_tcr = ensure_gs_pthread();
1713#endif
1714  TCR *tcr = get_interrupt_tcr(false);
1715  area *vs = tcr->vs_area;
1716  BytePtr current_sp = (BytePtr) current_stack_pointer();
1717
1718  if ((current_sp >= vs->low) &&
1719      (current_sp < vs->high)) {
1720    handle_signal_on_foreign_stack(tcr,
1721                                   interrupt_handler,
1722                                   signum,
1723                                   info,
1724                                   context,
1725                                   (LispObj)__builtin_return_address(0)
1726#ifdef DARWIN_GS_HACK
1727                                   ,gs_was_tcr
1728#endif
1729                                   );
1730  } else {
1731    /* If we're not on the value stack, we pretty much have to be on
1732       the C stack.  Just run the handler. */
1733#ifdef DARWIN_GS_HACK
1734    if (gs_was_tcr) {
1735      set_gs_address(tcr);
1736    }
1737#endif
1738    interrupt_handler(signum, info, context);
1739  }
1740}
1741
1742#else /* altstack works */
1743 
1744void
1745altstack_interrupt_handler (int signum, siginfo_t *info, ExceptionInformation *context)
1746{
1747#ifdef DARWIN_GS_HACK
1748  Boolean gs_was_tcr = ensure_gs_pthread();
1749#endif
1750  TCR *tcr = get_interrupt_tcr(false);
1751  handle_signal_on_foreign_stack(tcr,interrupt_handler,signum,info,context,(LispObj)__builtin_return_address(0)
1752#ifdef DARWIN_GS_HACK
1753                                 ,gs_was_tcr
1754#endif
1755                                 );
1756}
1757
1758#endif
1759#endif
1760
1761#ifndef WINDOWS
1762void
1763install_signal_handler(int signo, void * handler)
1764{
1765  struct sigaction sa;
1766 
1767  sa.sa_sigaction = (void *)handler;
1768  sigfillset(&sa.sa_mask);
1769#ifdef FREEBSD
1770  /* Strange FreeBSD behavior wrt synchronous signals */
1771  sigdelset(&sa.sa_mask,SIGTRAP);  /* let GDB work */
1772#endif
1773  sa.sa_flags = 
1774    0 /* SA_RESTART */
1775#ifdef USE_SIGALTSTACK
1776    | SA_ONSTACK
1777#endif
1778    | SA_SIGINFO;
1779
1780  sigaction(signo, &sa, NULL);
1781}
1782#endif
1783
1784#ifdef WINDOWS
1785BOOL
1786CALLBACK ControlEventHandler(DWORD event)
1787{
1788  switch(event) {
1789  case CTRL_C_EVENT:
1790    lisp_global(INTFLAG) = (1 << fixnumshift);
1791    return TRUE;
1792    break;
1793  default:
1794    return FALSE;
1795  }
1796}
1797
1798int
1799map_windows_exception_code_to_posix_signal(DWORD code)
1800{
1801  switch (code) {
1802  case EXCEPTION_ACCESS_VIOLATION:
1803    return SIGSEGV;
1804  case EXCEPTION_FLT_DENORMAL_OPERAND:
1805  case EXCEPTION_FLT_DIVIDE_BY_ZERO:
1806  case EXCEPTION_FLT_INEXACT_RESULT:
1807  case EXCEPTION_FLT_INVALID_OPERATION:
1808  case EXCEPTION_FLT_OVERFLOW:
1809  case EXCEPTION_FLT_STACK_CHECK:
1810  case EXCEPTION_FLT_UNDERFLOW:
1811  case EXCEPTION_INT_DIVIDE_BY_ZERO:
1812  case EXCEPTION_INT_OVERFLOW:
1813    return SIGFPE;
1814  case EXCEPTION_PRIV_INSTRUCTION:
1815  case EXCEPTION_ILLEGAL_INSTRUCTION:
1816    return SIGILL;
1817  case EXCEPTION_IN_PAGE_ERROR:
1818    return SIGBUS;
1819  default:
1820    return -1;
1821  }
1822}
1823
1824
1825LONG
1826windows_exception_handler(EXCEPTION_POINTERS *exception_pointers, TCR *tcr)
1827{
1828  DWORD code = exception_pointers->ExceptionRecord->ExceptionCode;
1829  int old_valence, signal_number;
1830  ExceptionInformation *context = exception_pointers->ContextRecord;
1831  siginfo_t *info = exception_pointers->ExceptionRecord;
1832  xframe_list xframes;
1833
1834  old_valence = prepare_to_wait_for_exception_lock(tcr, context);
1835  wait_for_exception_lock_in_handler(tcr, context, &xframes);
1836
1837  signal_number = map_windows_exception_code_to_posix_signal(code);
1838 
1839  if (!handle_exception(signal_number, info, context, tcr, old_valence)) {
1840    char msg[512];
1841    Boolean foreign = (old_valence != TCR_STATE_LISP);
1842
1843    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));
1844   
1845    if (lisp_Debugger(context, info, signal_number,  foreign, msg)) {
1846      SET_TCR_FLAG(tcr,TCR_FLAG_BIT_PROPAGATE_EXCEPTION);
1847    }
1848  }
1849  unlock_exception_lock_in_handler(tcr);
1850  return restore_windows_context(context, tcr, old_valence);
1851}
1852
1853void
1854setup_exception_handler_call(CONTEXT *context,
1855                             LispObj new_sp,
1856                             void *handler,
1857                             EXCEPTION_POINTERS *new_ep,
1858                             TCR *tcr)
1859{
1860  extern void windows_halt(void);
1861  LispObj *p = (LispObj *)new_sp;
1862#ifdef WIN_64
1863  p-=4;                         /* win64 abi argsave nonsense */
1864  *(--p) = (LispObj)windows_halt;
1865  context->Rsp = (DWORD64)p;
1866  context->Rip = (DWORD64)handler;
1867  context->Rcx = (DWORD64)new_ep;
1868  context->Rdx = (DWORD64)tcr;
1869#else
1870  p-=4;                          /* args on stack, stack aligned */
1871  p[0] = (LispObj)new_ep;
1872  p[1] = (LispObj)tcr;
1873  *(--p) = (LispObj)windows_halt;
1874  context->Esp = (DWORD)p;
1875  context->Eip = (DWORD)handler;
1876#ifdef WIN32_ES_HACK
1877  context->SegEs = context->SegDs;
1878#endif
1879#endif
1880  context->EFlags &= ~0x400;  /* clear direction flag */
1881}
1882
1883void
1884prepare_to_handle_windows_exception_on_foreign_stack(TCR *tcr,
1885                                                     CONTEXT *context,
1886                                                     void *handler,
1887                                                     EXCEPTION_POINTERS *original_ep)
1888{
1889  LispObj foreign_rsp = 
1890    (LispObj) (tcr->foreign_sp - 128) & ~15;
1891  CONTEXT *new_context;
1892  siginfo_t *new_info;
1893  EXCEPTION_POINTERS *new_ep;
1894
1895  new_context = ((CONTEXT *)(foreign_rsp&~15))-1;
1896  *new_context = *context;
1897  foreign_rsp = (LispObj)new_context;
1898  new_info = ((siginfo_t *)(foreign_rsp&~15))-1;
1899  *new_info = *original_ep->ExceptionRecord;
1900  foreign_rsp = (LispObj)new_info;
1901  new_ep = ((EXCEPTION_POINTERS *)(foreign_rsp&~15))-1;
1902  foreign_rsp = (LispObj)new_ep & ~15;
1903  new_ep->ContextRecord = new_context;
1904  new_ep->ExceptionRecord = new_info;
1905  setup_exception_handler_call(context,foreign_rsp,handler,new_ep, tcr);
1906}
1907
1908LONG CALLBACK
1909windows_arbstack_exception_handler(EXCEPTION_POINTERS *exception_pointers)
1910{
1911  extern void ensure_safe_for_string_operations(void);
1912  DWORD code = exception_pointers->ExceptionRecord->ExceptionCode;
1913
1914
1915 
1916  if ((code & 0x80000000L) == 0) {
1917    return EXCEPTION_CONTINUE_SEARCH;
1918  } else {
1919    TCR *tcr = get_interrupt_tcr(false);
1920    area *cs = tcr->cs_area;
1921    BytePtr current_sp = (BytePtr) current_stack_pointer();
1922    CONTEXT *context = exception_pointers->ContextRecord;
1923   
1924    ensure_safe_for_string_operations();
1925
1926    if ((current_sp >= cs->low) &&
1927        (current_sp < cs->high)) {
1928      debug_show_registers(context, exception_pointers->ExceptionRecord, 0);
1929      FBug(context, "Exception on foreign stack\n");
1930      return EXCEPTION_CONTINUE_EXECUTION;
1931    }
1932
1933    prepare_to_handle_windows_exception_on_foreign_stack(tcr,
1934                                                         context,
1935                                                         windows_exception_handler,
1936                                                         exception_pointers);
1937    return EXCEPTION_CONTINUE_EXECUTION;
1938  }
1939}
1940
1941
1942void
1943install_pmcl_exception_handlers()
1944{
1945  AddVectoredExceptionHandler(1,windows_arbstack_exception_handler);
1946}
1947#else
1948void
1949install_pmcl_exception_handlers()
1950{
1951#ifndef DARWIN 
1952  void *handler = (void *)
1953#ifdef USE_SIGALTSTACK
1954    altstack_signal_handler
1955#else
1956    arbstack_signal_handler;
1957#endif
1958  ;
1959  install_signal_handler(SIGILL, handler);
1960 
1961  install_signal_handler(SIGBUS, handler);
1962  install_signal_handler(SIGSEGV,handler);
1963  install_signal_handler(SIGFPE, handler);
1964#else
1965  install_signal_handler(SIGTRAP,bogus_signal_handler);
1966  install_signal_handler(SIGILL, bogus_signal_handler);
1967 
1968  install_signal_handler(SIGBUS, bogus_signal_handler);
1969  install_signal_handler(SIGSEGV,bogus_signal_handler);
1970  install_signal_handler(SIGFPE, bogus_signal_handler);
1971  /*  9.0.0d8 generates spurious SIGSYS from mach_msg_trap */
1972  install_signal_handler(SIGSYS, bogus_signal_handler);
1973#endif
1974 
1975  install_signal_handler(SIGNAL_FOR_PROCESS_INTERRUPT,
1976#ifdef USE_SIGALTSTACK
1977                         altstack_interrupt_handler
1978#else
1979                         arbstack_interrupt_handler
1980#endif
1981);
1982  signal(SIGPIPE, SIG_IGN);
1983}
1984#endif
1985
1986#ifndef WINDOWS
1987#ifndef USE_SIGALTSTACK
1988void
1989arbstack_suspend_resume_handler(int signum, siginfo_t *info, ExceptionInformation  *context)
1990{
1991#ifdef DARWIN_GS_HACK
1992  Boolean gs_was_tcr = ensure_gs_pthread();
1993#endif
1994  TCR *tcr = get_interrupt_tcr(false);
1995  area *vs = tcr->vs_area;
1996  BytePtr current_sp = (BytePtr) current_stack_pointer();
1997
1998  if ((current_sp >= vs->low) &&
1999      (current_sp < vs->high)) {
2000    handle_signal_on_foreign_stack(tcr,
2001                                   suspend_resume_handler,
2002                                   signum,
2003                                   info,
2004                                   context,
2005                                   (LispObj)__builtin_return_address(0)
2006#ifdef DARWIN_GS_HACK
2007                                   ,gs_was_tcr
2008#endif
2009                                   );
2010  } else {
2011    /* If we're not on the value stack, we pretty much have to be on
2012       the C stack.  Just run the handler. */
2013#ifdef DARWIN_GS_HACK
2014    if (gs_was_tcr) {
2015      set_gs_address(tcr);
2016    }
2017#endif
2018    suspend_resume_handler(signum, info, context);
2019  }
2020}
2021
2022
2023#else /* altstack works */
2024void
2025altstack_suspend_resume_handler(int signum, siginfo_t *info, ExceptionInformation  *context)
2026{
2027#ifdef DARWIN_GS_HACK
2028  Boolean gs_was_tcr = ensure_gs_pthread();
2029#endif
2030  TCR* tcr = get_tcr(true);
2031  handle_signal_on_foreign_stack(tcr,
2032                                 suspend_resume_handler,
2033                                 signum,
2034                                 info,
2035                                 context,
2036                                 (LispObj)__builtin_return_address(0)
2037#ifdef DARWIN_GS_HACK
2038                                 ,gs_was_tcr
2039#endif
2040                                 );
2041}
2042#endif
2043#endif
2044
2045
2046/* This should only be called when the tcr_area_lock is held */
2047void
2048empty_tcr_stacks(TCR *tcr)
2049{
2050  if (tcr) {
2051    area *a;
2052
2053    tcr->valence = TCR_STATE_FOREIGN;
2054    a = tcr->vs_area;
2055    if (a) {
2056      a->active = a->high;
2057    }
2058    a = tcr->ts_area;
2059    if (a) {
2060      a->active = a->high;
2061    }
2062    a = tcr->cs_area;
2063    if (a) {
2064      a->active = a->high;
2065    }
2066  }
2067}
2068
2069#ifdef WINDOWS
2070void
2071thread_kill_handler(int signum, siginfo_t *info, ExceptionInformation *xp)
2072{
2073}
2074#else
2075void
2076thread_kill_handler(int signum, siginfo_t *info, ExceptionInformation *xp)
2077{
2078#ifdef DARWIN_GS_HACK
2079  Boolean gs_was_tcr = ensure_gs_pthread();
2080#endif
2081  TCR *tcr = get_tcr(false);
2082  sigset_t mask;
2083
2084  sigemptyset(&mask);
2085
2086  empty_tcr_stacks(tcr);
2087
2088  pthread_sigmask(SIG_SETMASK,&mask,NULL);
2089  pthread_exit(NULL);
2090}
2091#endif
2092
2093#ifndef WINDOWS
2094#ifndef USE_SIGALTSTACK
2095void
2096arbstack_thread_kill_handler(int signum, siginfo_t *info, ExceptionInformation *context)
2097{
2098#ifdef DARWIN_GS_HACK
2099  Boolean gs_was_tcr = ensure_gs_pthread();
2100#endif
2101  TCR *tcr = get_interrupt_tcr(false);
2102  area *vs = tcr->vs_area;
2103  BytePtr current_sp = (BytePtr) current_stack_pointer();
2104
2105  if ((current_sp >= vs->low) &&
2106      (current_sp < vs->high)) {
2107    handle_signal_on_foreign_stack(tcr,
2108                                   thread_kill_handler,
2109                                   signum,
2110                                   info,
2111                                   context,
2112                                   (LispObj)__builtin_return_address(0)
2113#ifdef DARWIN_GS_HACK
2114                                   ,gs_was_tcr
2115#endif
2116                                   );
2117  } else {
2118    /* If we're not on the value stack, we pretty much have to be on
2119       the C stack.  Just run the handler. */
2120#ifdef DARWIN_GS_HACK
2121    if (gs_was_tcr) {
2122      set_gs_address(tcr);
2123    }
2124#endif
2125    thread_kill_handler(signum, info, context);
2126  }
2127}
2128
2129
2130#else
2131void
2132altstack_thread_kill_handler(int signum, siginfo_t *info, ExceptionInformation *context)
2133{
2134#ifdef DARWIN_GS_HACK
2135  Boolean gs_was_tcr = ensure_gs_pthread();
2136#endif
2137  TCR* tcr = get_tcr(true);
2138  handle_signal_on_foreign_stack(tcr,
2139                                 thread_kill_handler,
2140                                 signum,
2141                                 info,
2142                                 context,
2143                                 (LispObj)__builtin_return_address(0)
2144#ifdef DARWIN_GS_HACK
2145                                 ,gs_was_tcr
2146#endif
2147                                 );
2148}
2149#endif
2150#endif
2151
2152#ifdef USE_SIGALTSTACK
2153#define SUSPEND_RESUME_HANDLER altstack_suspend_resume_handler
2154#define THREAD_KILL_HANDLER altstack_thread_kill_handler
2155#else
2156#define SUSPEND_RESUME_HANDLER arbstack_suspend_resume_handler
2157#define THREAD_KILL_HANDLER arbstack_thread_kill_handler
2158#endif
2159
2160#ifdef WINDOWS
2161void
2162thread_signal_setup()
2163{
2164}
2165#else
2166void
2167thread_signal_setup()
2168{
2169  thread_suspend_signal = SIG_SUSPEND_THREAD;
2170  thread_kill_signal = SIG_KILL_THREAD;
2171
2172  install_signal_handler(thread_suspend_signal, (void *)SUSPEND_RESUME_HANDLER);
2173  install_signal_handler(thread_kill_signal, (void *)THREAD_KILL_HANDLER);
2174}
2175#endif
2176
2177void
2178enable_fp_exceptions()
2179{
2180}
2181
2182void
2183exception_init()
2184{
2185  install_pmcl_exception_handlers();
2186}
2187
2188void
2189adjust_exception_pc(ExceptionInformation *xp, int delta)
2190{
2191  xpPC(xp) += delta;
2192}
2193
2194/*
2195  Lower (move toward 0) the "end" of the soft protected area associated
2196  with a by a page, if we can.
2197*/
2198
2199void
2200
2201adjust_soft_protection_limit(area *a)
2202{
2203  char *proposed_new_soft_limit = a->softlimit - 4096;
2204  protected_area_ptr p = a->softprot;
2205 
2206  if (proposed_new_soft_limit >= (p->start+16384)) {
2207    p->end = proposed_new_soft_limit;
2208    p->protsize = p->end-p->start;
2209    a->softlimit = proposed_new_soft_limit;
2210  }
2211  protect_area(p);
2212}
2213
2214void
2215restore_soft_stack_limit(unsigned restore_tsp)
2216{
2217  TCR *tcr = get_tcr(false);
2218  area *a;
2219 
2220  if (restore_tsp) {
2221    a = tcr->ts_area;
2222  } else {
2223    a = tcr->vs_area;
2224  }
2225  adjust_soft_protection_limit(a);
2226}
2227
2228
2229#ifdef USE_SIGALTSTACK
2230void
2231setup_sigaltstack(area *a)
2232{
2233  stack_t stack;
2234  stack.ss_sp = a->low;
2235  a->low += SIGSTKSZ*8;
2236  stack.ss_size = SIGSTKSZ*8;
2237  stack.ss_flags = 0;
2238  mmap(stack.ss_sp,stack.ss_size, PROT_READ|PROT_WRITE|PROT_EXEC,MAP_FIXED|MAP_ANON|MAP_PRIVATE,-1,0);
2239  if (sigaltstack(&stack, NULL) != 0) {
2240    perror("sigaltstack");
2241    exit(-1);
2242  }
2243}
2244#endif
2245
2246extern opcode egc_write_barrier_start, egc_write_barrier_end,
2247  egc_set_hash_key_conditional, egc_set_hash_key_conditional_success_test,
2248  egc_store_node_conditional_success_end,
2249  egc_store_node_conditional_success_test,egc_store_node_conditional,
2250  egc_set_hash_key, egc_gvset, egc_rplacd;
2251
2252/* We use (extremely) rigidly defined instruction sequences for consing,
2253   mostly so that 'pc_luser_xp()' knows what to do if a thread is interrupted
2254   while consing.
2255
2256   Note that we can usually identify which of these instructions is about
2257   to be executed by a stopped thread without comparing all of the bytes
2258   to those at the stopped program counter, but we generally need to
2259   know the sizes of each of these instructions.
2260*/
2261
2262#ifdef X8664
2263opcode load_allocptr_reg_from_tcr_save_allocptr_instruction[] =
2264#ifdef WINDOWS
2265  {0x49,0x8b,0x9b,0xd8,0x00,0x00,0x00}
2266#else
2267  {0x65,0x48,0x8b,0x1c,0x25,0xd8,0x00,0x00,0x00}
2268#endif
2269;
2270opcode compare_allocptr_reg_to_tcr_save_allocbase_instruction[] =
2271#ifdef WINDOWS
2272  {0x49,0x3b,0x9b,0xe0,0x00,0x00,0x00}
2273#else
2274  {0x65,0x48,0x3b,0x1c,0x25,0xe0,0x00,0x00,0x00}
2275#endif
2276
2277;
2278opcode branch_around_alloc_trap_instruction[] =
2279  {0x7f,0x02};
2280opcode alloc_trap_instruction[] =
2281  {0xcd,0xc5};
2282opcode clear_tcr_save_allocptr_tag_instruction[] =
2283#ifdef WINDOWS
2284  {0x41,0x80,0xa3,0xd8,0x00,0x00,0x00,0xf0}
2285#else
2286  {0x65,0x80,0x24,0x25,0xd8,0x00,0x00,0x00,0xf0}
2287#endif
2288;
2289opcode set_allocptr_header_instruction[] =
2290  {0x48,0x89,0x43,0xf3};
2291
2292
2293alloc_instruction_id
2294recognize_alloc_instruction(pc program_counter)
2295{
2296  switch(program_counter[0]) {
2297  case 0xcd: return ID_alloc_trap_instruction;
2298  case 0x7f: return ID_branch_around_alloc_trap_instruction;
2299  case 0x48: return ID_set_allocptr_header_instruction;
2300#ifdef WINDOWS
2301  case 0x41: return ID_clear_tcr_save_allocptr_tag_instruction;
2302  case 0x49:
2303    switch(program_counter[1]) {
2304    case 0x8b: return ID_load_allocptr_reg_from_tcr_save_allocptr_instruction;
2305    case 0x3b: return ID_compare_allocptr_reg_to_tcr_save_allocbase_instruction;
2306    }
2307#else
2308  case 0x65: 
2309    switch(program_counter[1]) {
2310    case 0x80: return ID_clear_tcr_save_allocptr_tag_instruction;
2311    case 0x48:
2312      switch(program_counter[2]) {
2313      case 0x3b: return ID_compare_allocptr_reg_to_tcr_save_allocbase_instruction;
2314      case 0x8b: return ID_load_allocptr_reg_from_tcr_save_allocptr_instruction;
2315      }
2316    }
2317#endif
2318  default: break;
2319  }
2320  return ID_unrecognized_alloc_instruction;
2321}
2322#endif
2323#ifdef X8632
2324opcode load_allocptr_reg_from_tcr_save_allocptr_instruction[] =
2325  {0x64,0x8b,0x0d,0x84,0x00,0x00,0x00};
2326opcode compare_allocptr_reg_to_tcr_save_allocbase_instruction[] =
2327  {0x64,0x3b,0x0d,0x88,0x00,0x00,0x00};
2328opcode branch_around_alloc_trap_instruction[] =
2329  {0x7f,0x02};
2330opcode alloc_trap_instruction[] =
2331  {0xcd,0xc5};
2332opcode clear_tcr_save_allocptr_tag_instruction[] =
2333  {0x64,0x80,0x25,0x84,0x00,0x00,0x00,0xf8};
2334opcode set_allocptr_header_instruction[] =
2335  {0x0f,0x7e,0x41,0xfa};
2336
2337alloc_instruction_id
2338recognize_alloc_instruction(pc program_counter)
2339{
2340  switch(program_counter[0]) {
2341  case 0xcd: return ID_alloc_trap_instruction;
2342  case 0x7f: return ID_branch_around_alloc_trap_instruction;
2343  case 0x0f: return ID_set_allocptr_header_instruction;
2344  case 0x64: 
2345    switch(program_counter[1]) {
2346    case 0x80: return ID_clear_tcr_save_allocptr_tag_instruction;
2347    case 0x3b: return ID_compare_allocptr_reg_to_tcr_save_allocbase_instruction;
2348    case 0x8b: return ID_load_allocptr_reg_from_tcr_save_allocptr_instruction;
2349    }
2350  }
2351  return ID_unrecognized_alloc_instruction;
2352}
2353#endif     
2354
2355void
2356pc_luser_xp(ExceptionInformation *xp, TCR *tcr, signed_natural *interrupt_displacement)
2357{
2358  pc program_counter = (pc)xpPC(xp);
2359  int allocptr_tag = fulltag_of((LispObj)(tcr->save_allocptr));
2360
2361  if (allocptr_tag != 0) {
2362    alloc_instruction_id state = recognize_alloc_instruction(program_counter);
2363    signed_natural
2364      disp = (allocptr_tag == fulltag_cons) ?
2365      sizeof(cons) - fulltag_cons :
2366#ifdef X8664
2367      xpGPR(xp,Iimm1);
2368#else
2369      xpGPR(xp,Iimm0);
2370#endif
2371    LispObj new_vector;
2372
2373    if ((state == ID_unrecognized_alloc_instruction) ||
2374        ((state == ID_set_allocptr_header_instruction) &&
2375         (allocptr_tag != fulltag_misc))) {
2376      Bug(xp, "Can't determine state of thread 0x" LISP ", interrupted during memory allocation", tcr);
2377    }
2378    switch(state) {
2379    case ID_set_allocptr_header_instruction:
2380      /* We were consing a vector and we won.  Set the header of the new vector
2381         (in the allocptr register) to the header in %rax and skip over this
2382         instruction, then fall into the next case. */
2383      new_vector = xpGPR(xp,Iallocptr);
2384      deref(new_vector,0) = 
2385#ifdef X8664
2386        xpGPR(xp,Iimm0)
2387#else
2388        xpMMXreg(xp,Imm0)
2389#endif
2390        ;
2391
2392      xpPC(xp) += sizeof(set_allocptr_header_instruction);
2393      /* Fall thru */
2394    case ID_clear_tcr_save_allocptr_tag_instruction:
2395      tcr->save_allocptr = (void *)(((LispObj)tcr->save_allocptr) & ~fulltagmask);
2396      xpPC(xp) += sizeof(clear_tcr_save_allocptr_tag_instruction);
2397      break;
2398    case ID_alloc_trap_instruction:
2399      /* If we're looking at another thread, we're pretty much committed to
2400         taking the trap.  We don't want the allocptr register to be pointing
2401         into the heap, so make it point to (- VOID_ALLOCPTR disp), where 'disp'
2402         was determined above.
2403      */
2404      if (interrupt_displacement == NULL) {
2405        xpGPR(xp,Iallocptr) = VOID_ALLOCPTR - disp;
2406        tcr->save_allocptr = (void *)(VOID_ALLOCPTR - disp);
2407      } else {
2408        /* Back out, and tell the caller how to resume the allocation attempt */
2409        *interrupt_displacement = disp;
2410        xpGPR(xp,Iallocptr) = VOID_ALLOCPTR;
2411        tcr->save_allocptr += disp;
2412        xpPC(xp) -= (sizeof(branch_around_alloc_trap_instruction)+
2413                     sizeof(compare_allocptr_reg_to_tcr_save_allocbase_instruction) +
2414                     sizeof(load_allocptr_reg_from_tcr_save_allocptr_instruction));
2415      }
2416      break;
2417    case ID_branch_around_alloc_trap_instruction:
2418      /* If we'd take the branch - which is a "jg" - around the alloc trap,
2419         we might as well finish the allocation.  Otherwise, back out of the
2420         attempt. */
2421      {
2422        int flags = (int)eflags_register(xp);
2423       
2424        if ((!(flags & (1 << X86_ZERO_FLAG_BIT))) &&
2425            ((flags & (1 << X86_SIGN_FLAG_BIT)) ==
2426             (flags & (1 << X86_CARRY_FLAG_BIT)))) {
2427          /* The branch (jg) would have been taken.  Emulate taking it. */
2428          xpPC(xp) += (sizeof(branch_around_alloc_trap_instruction)+
2429                       sizeof(alloc_trap_instruction));
2430          if (allocptr_tag == fulltag_misc) {
2431            /* Slap the header on the new uvector */
2432            new_vector = xpGPR(xp,Iallocptr);
2433            deref(new_vector,0) = xpGPR(xp,Iimm0);
2434            xpPC(xp) += sizeof(set_allocptr_header_instruction);
2435          }
2436          tcr->save_allocptr = (void *)(((LispObj)tcr->save_allocptr) & ~fulltagmask);
2437          xpPC(xp) += sizeof(clear_tcr_save_allocptr_tag_instruction);
2438        } else {
2439          /* Back up */
2440          xpPC(xp) -= (sizeof(compare_allocptr_reg_to_tcr_save_allocbase_instruction) +
2441                       sizeof(load_allocptr_reg_from_tcr_save_allocptr_instruction));
2442          xpGPR(xp,Iallocptr) = VOID_ALLOCPTR;
2443          if (interrupt_displacement) {
2444            *interrupt_displacement = disp;
2445            tcr->save_allocptr += disp;
2446          } else {
2447            tcr->save_allocptr = (void *)(VOID_ALLOCPTR-disp);
2448          }
2449        }
2450      }
2451      break;
2452    case ID_compare_allocptr_reg_to_tcr_save_allocbase_instruction:
2453      xpGPR(xp,Iallocptr) = VOID_ALLOCPTR;
2454      xpPC(xp) -= sizeof(load_allocptr_reg_from_tcr_save_allocptr_instruction);
2455      /* Fall through */
2456    case ID_load_allocptr_reg_from_tcr_save_allocptr_instruction:
2457      if (interrupt_displacement) {
2458        tcr->save_allocptr += disp;
2459        *interrupt_displacement = disp;
2460      } else {
2461        tcr->save_allocptr = (void *)(VOID_ALLOCPTR-disp);
2462      }
2463      break;
2464    default: 
2465      break;
2466    }
2467    return;
2468  }
2469  if ((program_counter >= &egc_write_barrier_start) &&
2470      (program_counter < &egc_write_barrier_end)) {
2471    LispObj *ea = 0, val, root = 0;
2472    bitvector refbits = (bitvector)(lisp_global(REFBITS));
2473    Boolean need_store = true, need_check_memo = true, need_memoize_root = false;
2474
2475    if (program_counter >= &egc_set_hash_key_conditional) {
2476      if ((program_counter < &egc_set_hash_key_conditional_success_test) ||
2477          ((program_counter == &egc_set_hash_key_conditional_success_test) &&
2478           !(eflags_register(xp) & (1 << X86_ZERO_FLAG_BIT)))) {
2479        /* Back up the PC, try again */
2480        xpPC(xp) = (LispObj) &egc_set_hash_key_conditional;
2481        return;
2482      }
2483      /* The conditional store succeeded.  Set the refbit, return to ra0 */
2484      val = xpGPR(xp,Iarg_z);
2485#ifdef X8664
2486      root = xpGPR(xp,Iarg_x);
2487      ea = (LispObj*)(root + (unbox_fixnum((signed_natural) xpGPR(xp,Itemp0))));
2488#else
2489      root = xpGPR(xp,Itemp1);
2490      ea = (LispObj *)(root + misc_data_offset + xpGPR(xp,Itemp0));
2491#endif
2492      need_memoize_root = true;
2493      need_store = false;
2494      xpGPR(xp,Iarg_z) = t_value;
2495    } else if (program_counter >= &egc_store_node_conditional) {
2496      if ((program_counter < &egc_store_node_conditional_success_test) ||
2497          ((program_counter == &egc_store_node_conditional_success_test) &&
2498           !(eflags_register(xp) & (1 << X86_ZERO_FLAG_BIT)))) {
2499        /* Back up the PC, try again */
2500        xpPC(xp) = (LispObj) &egc_store_node_conditional;
2501        return;
2502      }
2503      if (program_counter >= &egc_store_node_conditional_success_end) {
2504        return;
2505      }
2506
2507      /* The conditional store succeeded.  Set the refbit, return to ra0 */
2508      val = xpGPR(xp,Iarg_z);
2509#ifdef X8664
2510      ea = (LispObj*)(xpGPR(xp,Iarg_x) + (unbox_fixnum((signed_natural)
2511                                                       xpGPR(xp,Itemp0))));
2512#else
2513      ea = (LispObj *)(misc_data_offset + xpGPR(xp,Itemp1) + xpGPR(xp,Itemp0));
2514#endif
2515      xpGPR(xp,Iarg_z) = t_value;
2516      need_store = false;
2517    } else if (program_counter >= &egc_set_hash_key) {
2518#ifdef X8664
2519      root = xpGPR(xp,Iarg_x);
2520#else
2521      root = xpGPR(xp,Itemp0);
2522#endif
2523      ea = (LispObj *) (root+xpGPR(xp,Iarg_y)+misc_data_offset);
2524      val = xpGPR(xp,Iarg_z);
2525      need_memoize_root = true;
2526    } else if (program_counter >= &egc_gvset) {
2527#ifdef X8664
2528      ea = (LispObj *) (xpGPR(xp,Iarg_x)+xpGPR(xp,Iarg_y)+misc_data_offset);
2529#else
2530      ea = (LispObj *) (xpGPR(xp,Itemp0)+xpGPR(xp,Iarg_y)+misc_data_offset);
2531#endif
2532      val = xpGPR(xp,Iarg_z);
2533    } else if (program_counter >= &egc_rplacd) {
2534      ea = (LispObj *) untag(xpGPR(xp,Iarg_y));
2535      val = xpGPR(xp,Iarg_z);
2536    } else {                      /* egc_rplaca */
2537      ea =  ((LispObj *) untag(xpGPR(xp,Iarg_y)))+1;
2538      val = xpGPR(xp,Iarg_z);
2539    }
2540    if (need_store) {
2541      *ea = val;
2542    }
2543    if (need_check_memo) {
2544      natural  bitnumber = area_dnode(ea, lisp_global(HEAP_START));
2545      if ((bitnumber < lisp_global(OLDSPACE_DNODE_COUNT)) &&
2546          ((LispObj)ea < val)) {
2547        atomic_set_bit(refbits, bitnumber);
2548        if (need_memoize_root) {
2549          bitnumber = area_dnode(root, lisp_global(HEAP_START));
2550          atomic_set_bit(refbits, bitnumber);
2551        }
2552      }
2553    }
2554    {
2555      /* These subprimitives are called via CALL/RET; need
2556         to pop the return address off the stack and set
2557         the PC there. */
2558      LispObj *sp = (LispObj *)xpGPR(xp,Isp), ra = *sp++;
2559      xpPC(xp) = ra;
2560      xpGPR(xp,Isp)=(LispObj)sp;
2561    }
2562    return;
2563  }
2564}
2565
2566
2567void
2568normalize_tcr(ExceptionInformation *xp, TCR *tcr, Boolean is_other_tcr)
2569{
2570  void *cur_allocptr = (void *)(tcr->save_allocptr);
2571  LispObj lisprsp;
2572  area *a;
2573
2574  if (xp) {
2575    if (is_other_tcr) {
2576      pc_luser_xp(xp, tcr, NULL);
2577    }
2578    a = tcr->vs_area;
2579    lisprsp = xpGPR(xp, Isp);
2580    if (((BytePtr)lisprsp >= a->low) &&
2581        ((BytePtr)lisprsp < a->high)) {
2582      a->active = (BytePtr)lisprsp;
2583    } else {
2584      a->active = (BytePtr) tcr->save_vsp;
2585    }
2586    a = tcr->ts_area;
2587    a->active = (BytePtr) tcr->save_tsp;
2588  } else {
2589    /* In ff-call; get area active pointers from tcr */
2590    tcr->vs_area->active = (BytePtr) tcr->save_vsp;
2591    tcr->ts_area->active = (BytePtr) tcr->save_tsp;
2592  }
2593  if (cur_allocptr) {
2594    update_bytes_allocated(tcr, cur_allocptr);
2595  }
2596  tcr->save_allocbase = (void *)VOID_ALLOCPTR;
2597  if (fulltag_of((LispObj)(tcr->save_allocptr)) == 0) {
2598    tcr->save_allocptr = (void *)VOID_ALLOCPTR;
2599  }
2600}
2601
2602
2603/* Suspend and "normalize" other tcrs, then call a gc-like function
2604   in that context.  Resume the other tcrs, then return what the
2605   function returned */
2606
2607TCR *gc_tcr = NULL;
2608
2609
2610signed_natural
2611gc_like_from_xp(ExceptionInformation *xp, 
2612                signed_natural(*fun)(TCR *, signed_natural), 
2613                signed_natural param)
2614{
2615  TCR *tcr = get_tcr(false), *other_tcr;
2616  int result;
2617  signed_natural inhibit;
2618
2619  suspend_other_threads(true);
2620  inhibit = (signed_natural)(lisp_global(GC_INHIBIT_COUNT));
2621  if (inhibit != 0) {
2622    if (inhibit > 0) {
2623      lisp_global(GC_INHIBIT_COUNT) = (LispObj)(-inhibit);
2624    }
2625    resume_other_threads(true);
2626    gc_deferred++;
2627    return 0;
2628  }
2629  gc_deferred = 0;
2630
2631  gc_tcr = tcr;
2632
2633  /* This is generally necessary if the current thread invoked the GC
2634     via an alloc trap, and harmless if the GC was invoked via a GC
2635     trap.  (It's necessary in the first case because the "allocptr"
2636     register - %rbx - may be pointing into the middle of something
2637     below tcr->save_allocbase, and we wouldn't want the GC to see
2638     that bogus pointer.) */
2639  xpGPR(xp, Iallocptr) = VOID_ALLOCPTR; 
2640
2641  normalize_tcr(xp, tcr, false);
2642
2643
2644  for (other_tcr = tcr->next; other_tcr != tcr; other_tcr = other_tcr->next) {
2645    if (other_tcr->pending_exception_context) {
2646      other_tcr->gc_context = other_tcr->pending_exception_context;
2647    } else if (other_tcr->valence == TCR_STATE_LISP) {
2648      other_tcr->gc_context = other_tcr->suspend_context;
2649    } else {
2650      /* no pending exception, didn't suspend in lisp state:
2651         must have executed a synchronous ff-call.
2652      */
2653      other_tcr->gc_context = NULL;
2654    }
2655    normalize_tcr(other_tcr->gc_context, other_tcr, true);
2656  }
2657   
2658
2659
2660  result = fun(tcr, param);
2661
2662  other_tcr = tcr;
2663  do {
2664    other_tcr->gc_context = NULL;
2665    other_tcr = other_tcr->next;
2666  } while (other_tcr != tcr);
2667
2668  gc_tcr = NULL;
2669
2670  resume_other_threads(true);
2671
2672  return result;
2673
2674}
2675
2676signed_natural
2677purify_from_xp(ExceptionInformation *xp, signed_natural param)
2678{
2679  return gc_like_from_xp(xp, purify, param);
2680}
2681
2682signed_natural
2683impurify_from_xp(ExceptionInformation *xp, signed_natural param)
2684{
2685  return gc_like_from_xp(xp, impurify, param);
2686}
2687
2688/* Returns #bytes freed by invoking GC */
2689
2690signed_natural
2691gc_from_tcr(TCR *tcr, signed_natural param)
2692{
2693  area *a;
2694  BytePtr oldfree, newfree;
2695  BytePtr oldend, newend;
2696
2697#if 0
2698  fprintf(stderr, "Start GC  in 0x" LISP "\n", tcr);
2699#endif
2700  a = active_dynamic_area;
2701  oldend = a->high;
2702  oldfree = a->active;
2703  gc(tcr, param);
2704  newfree = a->active;
2705  newend = a->high;
2706#if 0
2707  fprintf(stderr, "End GC  in 0x" LISP "\n", tcr);
2708#endif
2709  return ((oldfree-newfree)+(newend-oldend));
2710}
2711
2712signed_natural
2713gc_from_xp(ExceptionInformation *xp, signed_natural param)
2714{
2715  signed_natural status = gc_like_from_xp(xp, gc_from_tcr, param);
2716
2717  freeGCptrs();
2718  return status;
2719}
2720
2721#ifdef DARWIN
2722
2723#define TCR_FROM_EXCEPTION_PORT(p) ((TCR *)((natural)p))
2724#define TCR_TO_EXCEPTION_PORT(tcr) ((mach_port_t)((natural)(tcr)))
2725
2726extern void pseudo_sigreturn(void);
2727
2728
2729
2730#define LISP_EXCEPTIONS_HANDLED_MASK \
2731 (EXC_MASK_SOFTWARE | EXC_MASK_BAD_ACCESS | EXC_MASK_BAD_INSTRUCTION | EXC_MASK_ARITHMETIC)
2732
2733/* (logcount LISP_EXCEPTIONS_HANDLED_MASK) */
2734#define NUM_LISP_EXCEPTIONS_HANDLED 4
2735
2736typedef struct {
2737  int foreign_exception_port_count;
2738  exception_mask_t         masks[NUM_LISP_EXCEPTIONS_HANDLED];
2739  mach_port_t              ports[NUM_LISP_EXCEPTIONS_HANDLED];
2740  exception_behavior_t behaviors[NUM_LISP_EXCEPTIONS_HANDLED];
2741  thread_state_flavor_t  flavors[NUM_LISP_EXCEPTIONS_HANDLED];
2742} MACH_foreign_exception_state;
2743
2744
2745
2746
2747/*
2748  Mach's exception mechanism works a little better than its signal
2749  mechanism (and, not incidentally, it gets along with GDB a lot
2750  better.
2751
2752  Initially, we install an exception handler to handle each native
2753  thread's exceptions.  This process involves creating a distinguished
2754  thread which listens for kernel exception messages on a set of
2755  0 or more thread exception ports.  As threads are created, they're
2756  added to that port set; a thread's exception port is destroyed
2757  (and therefore removed from the port set) when the thread exits.
2758
2759  A few exceptions can be handled directly in the handler thread;
2760  others require that we resume the user thread (and that the
2761  exception thread resumes listening for exceptions.)  The user
2762  thread might eventually want to return to the original context
2763  (possibly modified somewhat.)
2764
2765  As it turns out, the simplest way to force the faulting user
2766  thread to handle its own exceptions is to do pretty much what
2767  signal() does: the exception handlng thread sets up a sigcontext
2768  on the user thread's stack and forces the user thread to resume
2769  execution as if a signal handler had been called with that
2770  context as an argument.  We can use a distinguished UUO at a
2771  distinguished address to do something like sigreturn(); that'll
2772  have the effect of resuming the user thread's execution in
2773  the (pseudo-) signal context.
2774
2775  Since:
2776    a) we have miles of code in C and in Lisp that knows how to
2777    deal with Linux sigcontexts
2778    b) Linux sigcontexts contain a little more useful information
2779    (the DAR, DSISR, etc.) than their Darwin counterparts
2780    c) we have to create a sigcontext ourselves when calling out
2781    to the user thread: we aren't really generating a signal, just
2782    leveraging existing signal-handling code.
2783
2784  we create a Linux sigcontext struct.
2785
2786  Simple ?  Hopefully from the outside it is ...
2787
2788  We want the process of passing a thread's own context to it to
2789  appear to be atomic: in particular, we don't want the GC to suspend
2790  a thread that's had an exception but has not yet had its user-level
2791  exception handler called, and we don't want the thread's exception
2792  context to be modified by a GC while the Mach handler thread is
2793  copying it around.  On Linux (and on Jaguar), we avoid this issue
2794  because (a) the kernel sets up the user-level signal handler and
2795  (b) the signal handler blocks signals (including the signal used
2796  by the GC to suspend threads) until tcr->xframe is set up.
2797
2798  The GC and the Mach server thread therefore contend for the lock
2799  "mach_exception_lock".  The Mach server thread holds the lock
2800  when copying exception information between the kernel and the
2801  user thread; the GC holds this lock during most of its execution
2802  (delaying exception processing until it can be done without
2803  GC interference.)
2804
2805*/
2806
2807#ifdef PPC64
2808#define C_REDZONE_LEN           320
2809#define C_STK_ALIGN             32
2810#else
2811#define C_REDZONE_LEN           224
2812#define C_STK_ALIGN             16
2813#endif
2814#define C_PARAMSAVE_LEN         64
2815#define C_LINKAGE_LEN           48
2816
2817#define TRUNC_DOWN(a,b,c)  (((((natural)a)-(b))/(c)) * (c))
2818
2819void
2820fatal_mach_error(char *format, ...);
2821
2822#define MACH_CHECK_ERROR(context,x) if (x != KERN_SUCCESS) {fatal_mach_error("Mach error while %s : %d", context, x);}
2823
2824
2825void
2826restore_mach_thread_state(mach_port_t thread, ExceptionInformation *pseudosigcontext)
2827{
2828  kern_return_t kret;
2829#if WORD_SIZE == 64
2830  MCONTEXT_T mc = UC_MCONTEXT(pseudosigcontext);
2831#else
2832  mcontext_t mc = UC_MCONTEXT(pseudosigcontext);
2833#endif
2834
2835  /* Set the thread's FP state from the pseudosigcontext */
2836#if WORD_SIZE == 64
2837  kret = thread_set_state(thread,
2838                          x86_FLOAT_STATE64,
2839                          (thread_state_t)&(mc->__fs),
2840                          x86_FLOAT_STATE64_COUNT);
2841#else
2842  kret = thread_set_state(thread,
2843                          x86_FLOAT_STATE32,
2844                          (thread_state_t)&(mc->__fs),
2845                          x86_FLOAT_STATE32_COUNT);
2846#endif
2847  MACH_CHECK_ERROR("setting thread FP state", kret);
2848
2849  /* The thread'll be as good as new ... */
2850#if WORD_SIZE == 64
2851  kret = thread_set_state(thread,
2852                          x86_THREAD_STATE64,
2853                          (thread_state_t)&(mc->__ss),
2854                          x86_THREAD_STATE64_COUNT);
2855#else
2856  kret = thread_set_state(thread, 
2857                          x86_THREAD_STATE32,
2858                          (thread_state_t)&(mc->__ss),
2859                          x86_THREAD_STATE32_COUNT);
2860#endif
2861  MACH_CHECK_ERROR("setting thread state", kret);
2862} 
2863
2864/* This code runs in the exception handling thread, in response
2865   to an attempt to execute the UU0 at "pseudo_sigreturn" (e.g.,
2866   in response to a call to pseudo_sigreturn() from the specified
2867   user thread.
2868   Find that context (the user thread's R3 points to it), then
2869   use that context to set the user thread's state.  When this
2870   function's caller returns, the Mach kernel will resume the
2871   user thread.
2872*/
2873
2874kern_return_t
2875do_pseudo_sigreturn(mach_port_t thread, TCR *tcr)
2876{
2877  ExceptionInformation *xp;
2878
2879#ifdef DEBUG_MACH_EXCEPTIONS
2880  fprintf(stderr, "doing pseudo_sigreturn for 0x%x\n",tcr);
2881#endif
2882  xp = tcr->pending_exception_context;
2883  if (xp) {
2884    tcr->pending_exception_context = NULL;
2885    tcr->valence = TCR_STATE_LISP;
2886    restore_mach_thread_state(thread, xp);
2887    raise_pending_interrupt(tcr);
2888  } else {
2889    Bug(NULL, "no xp here!\n");
2890  }
2891#ifdef DEBUG_MACH_EXCEPTIONS
2892  fprintf(stderr, "did pseudo_sigreturn for 0x%x\n",tcr);
2893#endif
2894  return KERN_SUCCESS;
2895} 
2896
2897ExceptionInformation *
2898create_thread_context_frame(mach_port_t thread, 
2899                            natural *new_stack_top,
2900                            siginfo_t **info_ptr,
2901                            TCR *tcr,
2902#ifdef X8664
2903                            x86_thread_state64_t *ts
2904#else
2905                            x86_thread_state32_t *ts
2906#endif
2907                            )
2908{
2909  mach_msg_type_number_t thread_state_count;
2910  ExceptionInformation *pseudosigcontext;
2911#ifdef X8664
2912  MCONTEXT_T mc;
2913#else
2914  mcontext_t mc;
2915#endif
2916  natural stackp;
2917
2918#ifdef X8664 
2919  stackp = (LispObj) find_foreign_rsp(ts->__rsp,tcr->cs_area,tcr);
2920  stackp = TRUNC_DOWN(stackp, C_REDZONE_LEN, C_STK_ALIGN);
2921#else
2922  stackp = (LispObj) find_foreign_rsp(ts->__esp, tcr->cs_area, tcr);
2923#endif
2924  stackp = TRUNC_DOWN(stackp, sizeof(siginfo_t), C_STK_ALIGN);
2925  if (info_ptr) {
2926    *info_ptr = (siginfo_t *)stackp;
2927  }
2928  stackp = TRUNC_DOWN(stackp,sizeof(*pseudosigcontext), C_STK_ALIGN);
2929  pseudosigcontext = (ExceptionInformation *) ptr_from_lispobj(stackp);
2930
2931  stackp = TRUNC_DOWN(stackp, sizeof(*mc), C_STK_ALIGN);
2932  mc = (MCONTEXT_T) ptr_from_lispobj(stackp);
2933 
2934  memmove(&(mc->__ss),ts,sizeof(*ts));
2935
2936#ifdef X8664
2937  thread_state_count = x86_FLOAT_STATE64_COUNT;
2938  thread_get_state(thread,
2939                   x86_FLOAT_STATE64,
2940                   (thread_state_t)&(mc->__fs),
2941                   &thread_state_count);
2942
2943  thread_state_count = x86_EXCEPTION_STATE64_COUNT;
2944  thread_get_state(thread,
2945                   x86_EXCEPTION_STATE64,
2946                   (thread_state_t)&(mc->__es),
2947                   &thread_state_count);
2948#else
2949  thread_state_count = x86_FLOAT_STATE32_COUNT;
2950  thread_get_state(thread,
2951                   x86_FLOAT_STATE32,
2952                   (thread_state_t)&(mc->__fs),
2953                   &thread_state_count);
2954
2955  thread_state_count = x86_EXCEPTION_STATE32_COUNT;
2956  thread_get_state(thread,
2957                   x86_EXCEPTION_STATE32,
2958                   (thread_state_t)&(mc->__es),
2959                   &thread_state_count);
2960#endif
2961
2962
2963  UC_MCONTEXT(pseudosigcontext) = mc;
2964  if (new_stack_top) {
2965    *new_stack_top = stackp;
2966  }
2967  return pseudosigcontext;
2968}
2969
2970/*
2971  This code sets up the user thread so that it executes a "pseudo-signal
2972  handler" function when it resumes.  Create a fake ucontext struct
2973  on the thread's stack and pass it as an argument to the pseudo-signal
2974  handler.
2975
2976  Things are set up so that the handler "returns to" pseudo_sigreturn(),
2977  which will restore the thread's context.
2978
2979  If the handler invokes code that throws (or otherwise never sigreturn()'s
2980  to the context), that's fine.
2981
2982  Actually, check that: throw (and variants) may need to be careful and
2983  pop the tcr's xframe list until it's younger than any frame being
2984  entered.
2985*/
2986
2987int
2988setup_signal_frame(mach_port_t thread,
2989                   void *handler_address,
2990                   int signum,
2991                   int code,
2992                   TCR *tcr,
2993#ifdef X8664
2994                   x86_thread_state64_t *ts
2995#else
2996                   x86_thread_state32_t *ts
2997#endif
2998                   )
2999{
3000#ifdef X8664
3001  x86_thread_state64_t new_ts;
3002#else
3003  x86_thread_state32_t new_ts;
3004#endif
3005  ExceptionInformation *pseudosigcontext;
3006  int  old_valence = tcr->valence;
3007  natural stackp, *stackpp;
3008  siginfo_t *info;
3009
3010#ifdef DEBUG_MACH_EXCEPTIONS
3011  fprintf(stderr,"Setting up exception handling for 0x%x\n", tcr);
3012#endif
3013  pseudosigcontext = create_thread_context_frame(thread, &stackp, &info, tcr,  ts);
3014  bzero(info, sizeof(*info));
3015  info->si_code = code;
3016  info->si_addr = (void *)(UC_MCONTEXT(pseudosigcontext)->__es.__faultvaddr);
3017  info->si_signo = signum;
3018  pseudosigcontext->uc_onstack = 0;
3019  pseudosigcontext->uc_sigmask = (sigset_t) 0;
3020  pseudosigcontext->uc_stack.ss_sp = 0;
3021  pseudosigcontext->uc_stack.ss_size = 0;
3022  pseudosigcontext->uc_stack.ss_flags = 0;
3023  pseudosigcontext->uc_link = NULL;
3024  pseudosigcontext->uc_mcsize = sizeof(*UC_MCONTEXT(pseudosigcontext));
3025  tcr->pending_exception_context = pseudosigcontext;
3026  tcr->valence = TCR_STATE_EXCEPTION_WAIT;
3027 
3028
3029  /*
3030     It seems like we've created a  sigcontext on the thread's
3031     stack.  Set things up so that we call the handler (with appropriate
3032     args) when the thread's resumed.
3033  */
3034
3035#ifdef X8664
3036  new_ts.__rip = (natural) handler_address;
3037  stackpp = (natural *)stackp;
3038  *--stackpp = (natural)pseudo_sigreturn;
3039  stackp = (natural)stackpp;
3040  new_ts.__rdi = signum;
3041  new_ts.__rsi = (natural)info;
3042  new_ts.__rdx = (natural)pseudosigcontext;
3043  new_ts.__rcx = (natural)tcr;
3044  new_ts.__r8 = (natural)old_valence;
3045  new_ts.__rsp = stackp;
3046  new_ts.__rflags = ts->__rflags;
3047#else
3048#define USER_CS 0x17
3049#define USER_DS 0x1f
3050  bzero(&new_ts, sizeof(new_ts));
3051  new_ts.__cs = ts->__cs;
3052  new_ts.__ss = ts->__ss;
3053  new_ts.__ds = ts->__ds;
3054  new_ts.__es = ts->__es;
3055  new_ts.__fs = ts->__fs;
3056  new_ts.__gs = ts->__gs;
3057
3058  new_ts.__eip = (natural)handler_address;
3059  stackpp = (natural *)stackp;
3060  *--stackpp = 0;               /* alignment */
3061  *--stackpp = 0;
3062  *--stackpp = 0;
3063  *--stackpp = (natural)old_valence;
3064  *--stackpp = (natural)tcr;
3065  *--stackpp = (natural)pseudosigcontext;
3066  *--stackpp = (natural)info;
3067  *--stackpp = (natural)signum;
3068  *--stackpp = (natural)pseudo_sigreturn;
3069  stackp = (natural)stackpp;
3070  new_ts.__esp = stackp;
3071  new_ts.__eflags = ts->__eflags;
3072#endif
3073
3074#ifdef X8664
3075  thread_set_state(thread,
3076                   x86_THREAD_STATE64,
3077                   (thread_state_t)&new_ts,
3078                   x86_THREAD_STATE64_COUNT);
3079#else
3080  thread_set_state(thread, 
3081                   x86_THREAD_STATE32,
3082                   (thread_state_t)&new_ts,
3083                   x86_THREAD_STATE32_COUNT);
3084#endif
3085#ifdef DEBUG_MACH_EXCEPTIONS
3086  fprintf(stderr,"Set up exception context for 0x%x at 0x%x\n", tcr, tcr->pending_exception_context);
3087#endif
3088  return 0;
3089}
3090
3091
3092
3093
3094
3095
3096/*
3097  This function runs in the exception handling thread.  It's
3098  called (by this precise name) from the library function "exc_server()"
3099  when the thread's exception ports are set up.  (exc_server() is called
3100  via mach_msg_server(), which is a function that waits for and dispatches
3101  on exception messages from the Mach kernel.)
3102
3103  This checks to see if the exception was caused by a pseudo_sigreturn()
3104  UUO; if so, it arranges for the thread to have its state restored
3105  from the specified context.
3106
3107  Otherwise, it tries to map the exception to a signal number and
3108  arranges that the thread run a "pseudo signal handler" to handle
3109  the exception.
3110
3111  Some exceptions could and should be handled here directly.
3112*/
3113
3114/* We need the thread's state earlier on x86_64 than we did on PPC;
3115   the PC won't fit in code_vector[1].  We shouldn't try to get it
3116   lazily (via catch_exception_raise_state()); until we own the
3117   exception lock, we shouldn't have it in userspace (since a GCing
3118   thread wouldn't know that we had our hands on it.)
3119*/
3120
3121#ifdef X8664
3122#define ts_pc(t) t.__rip
3123#else
3124#define ts_pc(t) t.__eip
3125#endif
3126
3127
3128#define DARWIN_EXCEPTION_HANDLER signal_handler
3129
3130
3131kern_return_t
3132catch_exception_raise(mach_port_t exception_port,
3133                      mach_port_t thread,
3134                      mach_port_t task, 
3135                      exception_type_t exception,
3136                      exception_data_t code_vector,
3137                      mach_msg_type_number_t code_count)
3138{
3139  int signum = 0, code = *code_vector;
3140  TCR *tcr = TCR_FROM_EXCEPTION_PORT(exception_port);
3141  kern_return_t kret, call_kret;
3142#ifdef X8664
3143  x86_thread_state64_t ts;
3144#else
3145  x86_thread_state32_t ts;
3146#endif
3147  mach_msg_type_number_t thread_state_count;
3148
3149
3150
3151#ifdef DEBUG_MACH_EXCEPTIONS
3152  fprintf(stderr, "obtaining Mach exception lock in exception thread\n");
3153#endif
3154
3155
3156  if (1) {
3157#ifdef X8664
3158    do {
3159      thread_state_count = x86_THREAD_STATE64_COUNT;
3160      call_kret = thread_get_state(thread,
3161                                   x86_THREAD_STATE64,
3162                                   (thread_state_t)&ts,
3163                                   &thread_state_count);
3164    } while (call_kret == KERN_ABORTED);
3165  MACH_CHECK_ERROR("getting thread state",call_kret);
3166#else
3167    thread_state_count = x86_THREAD_STATE32_COUNT;
3168    call_kret = thread_get_state(thread,
3169                                 x86_THREAD_STATE32,
3170                                 (thread_state_t)&ts,
3171                                 &thread_state_count);
3172    MACH_CHECK_ERROR("getting thread state",call_kret);
3173#endif
3174    if (tcr->flags & (1<<TCR_FLAG_BIT_PENDING_EXCEPTION)) {
3175      CLR_TCR_FLAG(tcr,TCR_FLAG_BIT_PENDING_EXCEPTION);
3176    } 
3177    if ((code == EXC_I386_GPFLT) &&
3178        ((natural)(ts_pc(ts)) == (natural)pseudo_sigreturn)) {
3179      kret = do_pseudo_sigreturn(thread, tcr);
3180#if 0
3181      fprintf(stderr, "Exception return in 0x%x\n",tcr);
3182#endif
3183    } else if (tcr->flags & (1<<TCR_FLAG_BIT_PROPAGATE_EXCEPTION)) {
3184      CLR_TCR_FLAG(tcr,TCR_FLAG_BIT_PROPAGATE_EXCEPTION);
3185      kret = 17;
3186    } else {
3187      switch (exception) {
3188      case EXC_BAD_ACCESS:
3189        if (code == EXC_I386_GPFLT) {
3190          signum = SIGSEGV;
3191        } else {
3192          signum = SIGBUS;
3193        }
3194        break;
3195       
3196      case EXC_BAD_INSTRUCTION:
3197        if (code == EXC_I386_GPFLT) {
3198          signum = SIGSEGV;
3199        } else {
3200          signum = SIGILL;
3201        }
3202        break;
3203         
3204      case EXC_SOFTWARE:
3205        signum = SIGILL;
3206        break;
3207       
3208      case EXC_ARITHMETIC:
3209        signum = SIGFPE;
3210        break;
3211       
3212      default:
3213        break;
3214      }
3215      if (signum) {
3216        kret = setup_signal_frame(thread,
3217                                  (void *)DARWIN_EXCEPTION_HANDLER,
3218                                  signum,
3219                                  code,
3220                                  tcr, 
3221                                  &ts);
3222#if 0
3223        fprintf(stderr, "Setup pseudosignal handling in 0x%x\n",tcr);
3224#endif
3225       
3226      } else {
3227        kret = 17;
3228      }
3229    }
3230  }
3231  return kret;
3232}
3233
3234
3235
3236
3237static mach_port_t mach_exception_thread = (mach_port_t)0;
3238
3239
3240/*
3241  The initial function for an exception-handling thread.
3242*/
3243
3244void *
3245exception_handler_proc(void *arg)
3246{
3247  extern boolean_t exc_server();
3248  mach_port_t p = TCR_TO_EXCEPTION_PORT(arg);
3249
3250  mach_exception_thread = pthread_mach_thread_np(pthread_self());
3251  mach_msg_server(exc_server, 256, p, 0);
3252  /* Should never return. */
3253  abort();
3254}
3255
3256
3257
3258void
3259mach_exception_thread_shutdown()
3260{
3261  kern_return_t kret;
3262
3263  fprintf(stderr, "terminating Mach exception thread, 'cause exit can't\n");
3264  kret = thread_terminate(mach_exception_thread);
3265  if (kret != KERN_SUCCESS) {
3266    fprintf(stderr, "Couldn't terminate exception thread, kret = %d\n",kret);
3267  }
3268}
3269
3270
3271mach_port_t
3272mach_exception_port_set()
3273{
3274  static mach_port_t __exception_port_set = MACH_PORT_NULL;
3275  kern_return_t kret; 
3276  if (__exception_port_set == MACH_PORT_NULL) {
3277
3278    kret = mach_port_allocate(mach_task_self(),
3279                              MACH_PORT_RIGHT_PORT_SET,
3280                              &__exception_port_set);
3281    MACH_CHECK_ERROR("allocating thread exception_ports",kret);
3282    create_system_thread(0,
3283                         NULL,
3284                         exception_handler_proc, 
3285                         (void *)((natural)__exception_port_set));
3286  }
3287  return __exception_port_set;
3288}
3289
3290/*
3291  Setup a new thread to handle those exceptions specified by
3292  the mask "which".  This involves creating a special Mach
3293  message port, telling the Mach kernel to send exception
3294  messages for the calling thread to that port, and setting
3295  up a handler thread which listens for and responds to
3296  those messages.
3297
3298*/
3299
3300/*
3301  Establish the lisp thread's TCR as its exception port, and determine
3302  whether any other ports have been established by foreign code for
3303  exceptions that lisp cares about.
3304
3305  If this happens at all, it should happen on return from foreign
3306  code and on entry to lisp code via a callback.
3307
3308  This is a lot of trouble (and overhead) to support Java, or other
3309  embeddable systems that clobber their caller's thread exception ports.
3310 
3311*/
3312kern_return_t
3313tcr_establish_exception_port(TCR *tcr, mach_port_t thread)
3314{
3315  kern_return_t kret;
3316  MACH_foreign_exception_state *fxs = (MACH_foreign_exception_state *)tcr->native_thread_info;
3317  int i;
3318  unsigned n = NUM_LISP_EXCEPTIONS_HANDLED;
3319  mach_port_t lisp_port = TCR_TO_EXCEPTION_PORT(tcr), foreign_port;
3320  exception_mask_t mask = 0;
3321
3322  kret = thread_swap_exception_ports(thread,
3323                                     LISP_EXCEPTIONS_HANDLED_MASK,
3324                                     lisp_port,
3325                                     EXCEPTION_DEFAULT,
3326                                     THREAD_STATE_NONE,
3327                                     fxs->masks,
3328                                     &n,
3329                                     fxs->ports,
3330                                     fxs->behaviors,
3331                                     fxs->flavors);
3332  if (kret == KERN_SUCCESS) {
3333    fxs->foreign_exception_port_count = n;
3334    for (i = 0; i < n; i ++) {
3335      foreign_port = fxs->ports[i];
3336
3337      if ((foreign_port != lisp_port) &&
3338          (foreign_port != MACH_PORT_NULL)) {
3339        mask |= fxs->masks[i];
3340      }
3341    }
3342    tcr->foreign_exception_status = (int) mask;
3343  }
3344  return kret;
3345}
3346
3347kern_return_t
3348tcr_establish_lisp_exception_port(TCR *tcr)
3349{
3350  return tcr_establish_exception_port(tcr, (mach_port_t)((natural)tcr->native_thread_id));
3351}
3352
3353/*
3354  Do this when calling out to or returning from foreign code, if
3355  any conflicting foreign exception ports were established when we
3356  last entered lisp code.
3357*/
3358kern_return_t
3359restore_foreign_exception_ports(TCR *tcr)
3360{
3361  exception_mask_t m = (exception_mask_t) tcr->foreign_exception_status;
3362 
3363  if (m) {
3364    MACH_foreign_exception_state *fxs  = 
3365      (MACH_foreign_exception_state *) tcr->native_thread_info;
3366    int i, n = fxs->foreign_exception_port_count;
3367    exception_mask_t tm;
3368
3369    for (i = 0; i < n; i++) {
3370      if ((tm = fxs->masks[i]) & m) {
3371        thread_set_exception_ports((mach_port_t)((natural)tcr->native_thread_id),
3372                                   tm,
3373                                   fxs->ports[i],
3374                                   fxs->behaviors[i],
3375                                   fxs->flavors[i]);
3376      }
3377    }
3378  }
3379}
3380                                   
3381
3382/*
3383  This assumes that a Mach port (to be used as the thread's exception port) whose
3384  "name" matches the TCR's 32-bit address has already been allocated.
3385*/
3386
3387kern_return_t
3388setup_mach_exception_handling(TCR *tcr)
3389{
3390  mach_port_t
3391    thread_exception_port = TCR_TO_EXCEPTION_PORT(tcr),
3392    task_self = mach_task_self();
3393  kern_return_t kret;
3394
3395  kret = mach_port_insert_right(task_self,
3396                                thread_exception_port,
3397                                thread_exception_port,
3398                                MACH_MSG_TYPE_MAKE_SEND);
3399  MACH_CHECK_ERROR("adding send right to exception_port",kret);
3400
3401  kret = tcr_establish_exception_port(tcr, (mach_port_t)((natural) tcr->native_thread_id));
3402  if (kret == KERN_SUCCESS) {
3403    mach_port_t exception_port_set = mach_exception_port_set();
3404
3405    kret = mach_port_move_member(task_self,
3406                                 thread_exception_port,
3407                                 exception_port_set);
3408  }
3409  return kret;
3410}
3411
3412void
3413darwin_exception_init(TCR *tcr)
3414{
3415  void tcr_monitor_exception_handling(TCR*, Boolean);
3416  kern_return_t kret;
3417  MACH_foreign_exception_state *fxs = 
3418    calloc(1, sizeof(MACH_foreign_exception_state));
3419 
3420  tcr->native_thread_info = (void *) fxs;
3421
3422  if ((kret = setup_mach_exception_handling(tcr))
3423      != KERN_SUCCESS) {
3424    fprintf(stderr, "Couldn't setup exception handler - error = %d\n", kret);
3425    terminate_lisp();
3426  }
3427  lisp_global(LISP_EXIT_HOOK) = (LispObj) restore_foreign_exception_ports;
3428  lisp_global(LISP_RETURN_HOOK) = (LispObj) tcr_establish_lisp_exception_port;
3429}
3430
3431/*
3432  The tcr is the "name" of the corresponding thread's exception port.
3433  Destroying the port should remove it from all port sets of which it's
3434  a member (notably, the exception port set.)
3435*/
3436void
3437darwin_exception_cleanup(TCR *tcr)
3438{
3439  void *fxs = tcr->native_thread_info;
3440  extern Boolean use_mach_exception_handling;
3441
3442  if (fxs) {
3443    tcr->native_thread_info = NULL;
3444    free(fxs);
3445  }
3446  if (use_mach_exception_handling) {
3447    mach_port_deallocate(mach_task_self(),TCR_TO_EXCEPTION_PORT(tcr));
3448    mach_port_destroy(mach_task_self(),TCR_TO_EXCEPTION_PORT(tcr));
3449  }
3450}
3451
3452
3453Boolean
3454suspend_mach_thread(mach_port_t mach_thread)
3455{
3456  kern_return_t status;
3457  Boolean aborted = false;
3458 
3459  do {
3460    aborted = false;
3461    status = thread_suspend(mach_thread);
3462    if (status == KERN_SUCCESS) {
3463      status = thread_abort_safely(mach_thread);
3464      if (status == KERN_SUCCESS) {
3465        aborted = true;
3466      } else {
3467        fprintf(stderr, "abort failed on thread = 0x%x\n",mach_thread);
3468        thread_resume(mach_thread);
3469      }
3470    } else {
3471      return false;
3472    }
3473  } while (! aborted);
3474  return true;
3475}
3476
3477/*
3478  Only do this if pthread_kill indicated that the pthread isn't
3479  listening to signals anymore, as can happen as soon as pthread_exit()
3480  is called on Darwin.  The thread could still call out to lisp as it
3481  is exiting, so we need another way to suspend it in this case.
3482*/
3483Boolean
3484mach_suspend_tcr(TCR *tcr)
3485{
3486  mach_port_t mach_thread = (mach_port_t)((natural)( tcr->native_thread_id));
3487  ExceptionInformation *pseudosigcontext;
3488  Boolean result = false;
3489 
3490  result = suspend_mach_thread(mach_thread);
3491  if (result) {
3492    mach_msg_type_number_t thread_state_count;
3493#ifdef X8664
3494    x86_thread_state64_t ts;
3495    thread_state_count = x86_THREAD_STATE64_COUNT;
3496    thread_get_state(mach_thread,
3497                     x86_THREAD_STATE64,
3498                     (thread_state_t)&ts,
3499                     &thread_state_count);
3500#else
3501    x86_thread_state32_t ts;
3502    thread_state_count = x86_THREAD_STATE_COUNT;
3503    thread_get_state(mach_thread,
3504                     x86_THREAD_STATE,
3505                     (thread_state_t)&ts,
3506                     &thread_state_count);
3507#endif
3508
3509    pseudosigcontext = create_thread_context_frame(mach_thread, NULL, NULL,tcr, &ts);
3510    pseudosigcontext->uc_onstack = 0;
3511    pseudosigcontext->uc_sigmask = (sigset_t) 0;
3512    tcr->suspend_context = pseudosigcontext;
3513  }
3514  return result;
3515}
3516
3517void
3518mach_resume_tcr(TCR *tcr)
3519{
3520  ExceptionInformation *xp;
3521  mach_port_t mach_thread = (mach_port_t)((natural)(tcr->native_thread_id));
3522 
3523  xp = tcr->suspend_context;
3524#ifdef DEBUG_MACH_EXCEPTIONS
3525  fprintf(stderr, "resuming TCR 0x%x, pending_exception_context = 0x%x\n",
3526          tcr, tcr->pending_exception_context);
3527#endif
3528  tcr->suspend_context = NULL;
3529  restore_mach_thread_state(mach_thread, xp);
3530#ifdef DEBUG_MACH_EXCEPTIONS
3531  fprintf(stderr, "restored state in TCR 0x%x, pending_exception_context = 0x%x\n",
3532          tcr, tcr->pending_exception_context);
3533#endif
3534  thread_resume(mach_thread);
3535}
3536
3537void
3538fatal_mach_error(char *format, ...)
3539{
3540  va_list args;
3541  char s[512];
3542 
3543
3544  va_start(args, format);
3545  vsnprintf(s, sizeof(s),format, args);
3546  va_end(args);
3547
3548  Fatal("Mach error", s);
3549}
3550
3551
3552
3553
3554#endif
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