source: trunk/source/lisp-kernel/x86-exceptions.c @ 11793

Last change on this file since 11793 was 11793, checked in by gb, 11 years ago

In pc_luser_xp(): if we're interrupted in set_hash_key_conditional:

  • if we aren't at set_hash_key_conditional_retry yet, do nothing (x8632 modifying arg in temp0).
  • if we're past set_hash_key_conditional and not at set_hash_key_conditional success test (or at the success test with the Z flag clear), resume at set_hash_key_conditiona_retry (don't repeat the modification of temp0 on x8632.)
  • Property svn:eol-style set to native
  • Property svn:keywords set to Author Date Id Revision
File size: 97.7 KB
Line 
1/*
2   Copyright (C) 2005 Clozure Associates
3   This file is part of OpenMCL. 
4
5   OpenMCL is licensed under the terms of the Lisp Lesser GNU Public
6   License , known as the LLGPL and distributed with OpenMCL as the
7   file "LICENSE".  The LLGPL consists of a preamble and the LGPL,
8   which is distributed with OpenMCL as the file "LGPL".  Where these
9   conflict, the preamble takes precedence. 
10
11   OpenMCL is referenced in the preamble as the "LIBRARY."
12
13   The LLGPL is also available online at
14   http://opensource.franz.com/preamble.html
15*/
16
17#include "lisp.h"
18#include "lisp-exceptions.h"
19#include "lisp_globals.h"
20#include "Threads.h"
21#include <ctype.h>
22#include <stdio.h>
23#include <stddef.h>
24#include <string.h>
25#include <stdarg.h>
26#include <errno.h>
27#include <stdio.h>
28#ifdef LINUX
29#include <strings.h>
30#include <sys/mman.h>
31#include <fpu_control.h>
32#include <linux/prctl.h>
33#endif
34#ifdef DARWIN
35#include <sysexits.h>
36#endif
37#ifndef WINDOWS
38#include <sys/syslog.h>
39#endif
40#ifdef WINDOWS
41#include <windows.h>
42#ifdef WIN_64
43#include <winternl.h>
44#include <ntstatus.h>
45#endif
46#ifndef EXCEPTION_WRITE_FAULT
47#define EXCEPTION_WRITE_FAULT 1
48#endif
49#endif
50
51int
52page_size = 4096;
53
54int
55log2_page_size = 12;
56
57
58void
59update_bytes_allocated(TCR* tcr, void *cur_allocptr)
60{
61  BytePtr
62    last = (BytePtr) tcr->last_allocptr, 
63    current = (BytePtr) cur_allocptr;
64  if (last && (tcr->save_allocbase != ((void *)VOID_ALLOCPTR))) {
65    tcr->bytes_allocated += last-current;
66  }
67  tcr->last_allocptr = 0;
68}
69
70
71
72//  This doesn't GC; it returns true if it made enough room, false
73//  otherwise.
74//  If "extend" is true, it can try to extend the dynamic area to
75//  satisfy the request.
76
77
78Boolean
79new_heap_segment(ExceptionInformation *xp, natural need, Boolean extend, TCR *tcr)
80{
81  area *a;
82  natural newlimit, oldlimit;
83  natural log2_allocation_quantum = tcr->log2_allocation_quantum;
84
85  a  = active_dynamic_area;
86  oldlimit = (natural) a->active;
87  newlimit = (align_to_power_of_2(oldlimit, log2_allocation_quantum) +
88              align_to_power_of_2(need, log2_allocation_quantum));
89  if (newlimit > (natural) (a->high)) {
90    if (extend) {
91      signed_natural inhibit = (signed_natural)(lisp_global(GC_INHIBIT_COUNT));
92      natural extend_by = inhibit ? 0 : lisp_heap_gc_threshold;
93      do {
94        if (resize_dynamic_heap(a->active, (newlimit-oldlimit)+extend_by)) {
95          break;
96        }
97        extend_by = align_to_power_of_2(extend_by>>1,log2_allocation_quantum);
98        if (extend_by < 4<<20) {
99          return false;
100        }
101      } while (1);
102    } else {
103      return false;
104    }
105  }
106  a->active = (BytePtr) newlimit;
107  tcr->last_allocptr = (void *)newlimit;
108  tcr->save_allocptr = (void *)newlimit;
109  xpGPR(xp,Iallocptr) = (LispObj) newlimit;
110  tcr->save_allocbase = (void *) oldlimit;
111
112  return true;
113}
114
115Boolean
116allocate_object(ExceptionInformation *xp,
117                natural bytes_needed, 
118                signed_natural disp_from_allocptr,
119                TCR *tcr)
120{
121  area *a = active_dynamic_area;
122
123  /* Maybe do an EGC */
124  if (a->older && lisp_global(OLDEST_EPHEMERAL)) {
125    if (((a->active)-(a->low)) >= a->threshold) {
126      gc_from_xp(xp, 0L);
127    }
128  }
129
130  /* Life is pretty simple if we can simply grab a segment
131     without extending the heap.
132  */
133  if (new_heap_segment(xp, bytes_needed, false, tcr)) {
134    xpGPR(xp, Iallocptr) -= disp_from_allocptr;
135    tcr->save_allocptr = (void *) (xpGPR(xp, Iallocptr));
136    return true;
137  }
138 
139  /* It doesn't make sense to try a full GC if the object
140     we're trying to allocate is larger than everything
141     allocated so far.
142  */
143  if ((lisp_global(HEAP_END)-lisp_global(HEAP_START)) > bytes_needed) {
144    untenure_from_area(tenured_area); /* force a full GC */
145    gc_from_xp(xp, 0L);
146  }
147 
148  /* Try again, growing the heap if necessary */
149  if (new_heap_segment(xp, bytes_needed, true, tcr)) {
150    xpGPR(xp, Iallocptr) -= disp_from_allocptr;
151    tcr->save_allocptr = (void *) (xpGPR(xp, Iallocptr));
152    return true;
153  }
154 
155  return false;
156}
157
158natural gc_deferred = 0, full_gc_deferred = 0;
159
160signed_natural
161flash_freeze(TCR *tcr, signed_natural param)
162{
163  return 0;
164}
165
166
167Boolean
168handle_gc_trap(ExceptionInformation *xp, TCR *tcr)
169{
170  LispObj selector = xpGPR(xp,Iimm0);
171#ifdef X8664
172  LispObj arg = xpGPR(xp,Iimm1);
173#else
174  LispObj arg = xpMMXreg(xp,Imm0);
175#endif
176  area *a = active_dynamic_area;
177  Boolean egc_was_enabled = (a->older != NULL);
178 
179  natural gc_previously_deferred = gc_deferred;
180
181  switch (selector) {
182  case GC_TRAP_FUNCTION_EGC_CONTROL:
183    egc_control(arg != 0, a->active);
184    xpGPR(xp,Iarg_z) = lisp_nil + (egc_was_enabled ? t_offset : 0);
185    break;
186
187  case GC_TRAP_FUNCTION_CONFIGURE_EGC:
188#ifdef X8664
189    a->threshold = unbox_fixnum(xpGPR(xp, Iarg_x));
190#else
191    a->threshold = unbox_fixnum(xpGPR(xp, Itemp0));
192#endif
193    g1_area->threshold = unbox_fixnum(xpGPR(xp, Iarg_y));
194    g2_area->threshold = unbox_fixnum(xpGPR(xp, Iarg_z));
195    xpGPR(xp,Iarg_z) = lisp_nil+t_offset;
196    break;
197
198  case GC_TRAP_FUNCTION_SET_LISP_HEAP_THRESHOLD:
199    if (((signed_natural) arg) > 0) {
200      lisp_heap_gc_threshold = 
201        align_to_power_of_2((arg-1) +
202                            (heap_segment_size - 1),
203                            log2_heap_segment_size);
204    }
205    /* fall through */
206  case GC_TRAP_FUNCTION_GET_LISP_HEAP_THRESHOLD:
207    xpGPR(xp, Iimm0) = lisp_heap_gc_threshold;
208    break;
209
210  case GC_TRAP_FUNCTION_USE_LISP_HEAP_THRESHOLD:
211    /*  Try to put the current threshold in effect.  This may
212        need to disable/reenable the EGC. */
213    untenure_from_area(tenured_area);
214    resize_dynamic_heap(a->active,lisp_heap_gc_threshold);
215    if (egc_was_enabled) {
216      if ((a->high - a->active) >= a->threshold) {
217        tenure_to_area(tenured_area);
218      }
219    }
220    xpGPR(xp, Iimm0) = lisp_heap_gc_threshold;
221    break;
222
223  case GC_TRAP_FUNCTION_FLASH_FREEZE: /* Like freeze below, but no GC */
224    untenure_from_area(tenured_area);
225    gc_like_from_xp(xp,flash_freeze,0);
226    a->active = (BytePtr) align_to_power_of_2(a->active, log2_page_size);
227    tenured_area->static_dnodes = area_dnode(a->active, a->low);
228    if (egc_was_enabled) {
229      tenure_to_area(tenured_area);
230    }
231    xpGPR(xp, Iimm0) = tenured_area->static_dnodes << dnode_shift;
232    break;
233
234  default:
235    update_bytes_allocated(tcr, (void *) tcr->save_allocptr);
236
237    if (selector == GC_TRAP_FUNCTION_IMMEDIATE_GC) {
238      if (!full_gc_deferred) {
239        gc_from_xp(xp, 0L);
240        break;
241      }
242      /* Tried to do a full GC when gc was disabled.  That failed,
243         so try full GC now */
244      selector = GC_TRAP_FUNCTION_GC;
245    }
246   
247    if (egc_was_enabled) {
248      egc_control(false, (BytePtr) a->active);
249    }
250    gc_from_xp(xp, 0L);
251    if (gc_deferred > gc_previously_deferred) {
252      full_gc_deferred = 1;
253    } else {
254      full_gc_deferred = 0;
255    }
256    if (selector > GC_TRAP_FUNCTION_GC) {
257      if (selector & GC_TRAP_FUNCTION_IMPURIFY) {
258        impurify_from_xp(xp, 0L);
259        /*        nrs_GC_EVENT_STATUS_BITS.vcell |= gc_integrity_check_bit; */
260        gc_from_xp(xp, 0L);
261        release_readonly_area();
262      }
263      if (selector & GC_TRAP_FUNCTION_PURIFY) {
264        purify_from_xp(xp, 0L);
265        gc_from_xp(xp, 0L);
266      }
267      if (selector & GC_TRAP_FUNCTION_SAVE_APPLICATION) {
268        OSErr err;
269        extern OSErr save_application(unsigned, Boolean);
270        area *vsarea = tcr->vs_area;
271
272#ifdef WINDOWS 
273        arg = _open_osfhandle(arg,0);
274#endif
275        nrs_TOPLFUNC.vcell = *((LispObj *)(vsarea->high)-1);
276        err = save_application(arg, egc_was_enabled);
277        if (err == noErr) {
278          _exit(0);
279        }
280        fatal_oserr(": save_application", err);
281      }
282      switch (selector) {
283      case GC_TRAP_FUNCTION_SET_HONS_AREA_SIZE:
284        xpGPR(xp, Iimm0) = 0;
285        break;
286      case GC_TRAP_FUNCTION_FREEZE:
287        a->active = (BytePtr) align_to_power_of_2(a->active, log2_page_size);
288        tenured_area->static_dnodes = area_dnode(a->active, a->low);
289        xpGPR(xp, Iimm0) = tenured_area->static_dnodes << dnode_shift;
290        break;
291      default:
292        break;
293      }
294    }
295    if (egc_was_enabled) {
296      egc_control(true, NULL);
297    }
298    break;
299  }
300  return true;
301}
302
303 
304
305
306
307void
308push_on_lisp_stack(ExceptionInformation *xp, LispObj value)
309{
310  LispObj *vsp = (LispObj *)xpGPR(xp,Isp);
311  *--vsp = value;
312  xpGPR(xp,Isp) = (LispObj)vsp;
313}
314
315
316/* Hard to know if or whether this is necessary in general.  For now,
317   do it when we get a "wrong number of arguments" trap.
318*/
319void
320finish_function_entry(ExceptionInformation *xp)
321{
322#ifdef X8664
323  natural nargs = (xpGPR(xp,Inargs)&0xffff)>> fixnumshift;
324#else
325  natural nargs = xpGPR(xp,Inargs)>>fixnumshift;
326#endif
327  signed_natural disp;
328  LispObj *vsp =  (LispObj *) xpGPR(xp,Isp), ra = *vsp++;
329   
330  xpGPR(xp,Isp) = (LispObj) vsp;
331
332#ifdef X8664
333  disp = nargs - 3;
334#endif
335#ifdef X8632
336  disp = nargs - 2;
337#endif
338
339#ifdef X8664
340  if (disp > 0) {               /* implies that nargs > 3 */
341    vsp[disp] = xpGPR(xp,Irbp);
342    vsp[disp+1] = ra;
343    xpGPR(xp,Irbp) = (LispObj)(vsp+disp);
344    push_on_lisp_stack(xp,xpGPR(xp,Iarg_x));
345    push_on_lisp_stack(xp,xpGPR(xp,Iarg_y));
346    push_on_lisp_stack(xp,xpGPR(xp,Iarg_z));
347  } else {
348    push_on_lisp_stack(xp,ra);
349    push_on_lisp_stack(xp,xpGPR(xp,Irbp));
350    xpGPR(xp,Irbp) = xpGPR(xp,Isp);
351    if (nargs == 3) {
352      push_on_lisp_stack(xp,xpGPR(xp,Iarg_x));
353    }
354    if (nargs >= 2) {
355      push_on_lisp_stack(xp,xpGPR(xp,Iarg_y));
356    }
357    if (nargs >= 1) {
358      push_on_lisp_stack(xp,xpGPR(xp,Iarg_z));
359    }
360  }
361#endif
362#ifdef X8632
363  if (disp > 0) {               /* implies that nargs > 2 */
364    vsp[disp] = xpGPR(xp,Iebp);
365    vsp[disp+1] = ra;
366    xpGPR(xp,Iebp) = (LispObj)(vsp+disp);
367    xpGPR(xp,Isp) = (LispObj)vsp;
368    push_on_lisp_stack(xp,xpGPR(xp,Iarg_y));
369    push_on_lisp_stack(xp,xpGPR(xp,Iarg_z));
370  } else {
371    push_on_lisp_stack(xp,ra);
372    push_on_lisp_stack(xp,xpGPR(xp,Iebp));
373    xpGPR(xp,Iebp) = xpGPR(xp,Isp);
374    if (nargs == 2) {
375      push_on_lisp_stack(xp,xpGPR(xp,Iarg_y));
376    }
377    if (nargs >= 1) {
378      push_on_lisp_stack(xp,xpGPR(xp,Iarg_z));
379    }
380  }
381#endif
382}
383
384Boolean
385object_contains_pc(LispObj container, LispObj addr)
386{
387  if (fulltag_of(container) >= fulltag_misc) {
388    natural elements = header_element_count(header_of(container));
389    if ((addr >= container) &&
390        (addr < ((LispObj)&(deref(container,1+elements))))) {
391      return true;
392    }
393  }
394  return false;
395}
396
397LispObj
398create_exception_callback_frame(ExceptionInformation *xp, TCR *tcr)
399{
400  LispObj containing_uvector = 0, 
401    relative_pc, 
402    nominal_function = lisp_nil, 
403    f, tra, tra_f = 0, abs_pc;
404
405  f = xpGPR(xp,Ifn);
406  tra = *(LispObj*)(xpGPR(xp,Isp));
407
408#ifdef X8664
409  if (tag_of(tra) == tag_tra) {
410    if ((*((unsigned short *)tra) == RECOVER_FN_FROM_RIP_WORD0) &&
411        (*((unsigned char *)(tra+2)) == RECOVER_FN_FROM_RIP_BYTE2)) {
412      int sdisp = (*(int *) (tra+3));
413      tra_f = RECOVER_FN_FROM_RIP_LENGTH+tra+sdisp;
414    }
415    if (fulltag_of(tra_f) != fulltag_function) {
416      tra_f = 0;
417    }
418  } else {
419    tra = 0;
420  }
421#endif
422#ifdef X8632
423  if (fulltag_of(tra) == fulltag_tra) {
424    if (*(unsigned char *)tra == RECOVER_FN_OPCODE) {
425      tra_f = (LispObj)*(LispObj *)(tra + 1);
426    }
427    if (tra_f && header_subtag(header_of(tra_f)) != subtag_function) {
428      tra_f = 0;
429    }
430  } else {
431    tra = 0;
432  }
433#endif
434
435  abs_pc = (LispObj)xpPC(xp);
436
437#ifdef X8664
438  if (fulltag_of(f) == fulltag_function) 
439#else
440    if (fulltag_of(f) == fulltag_misc &&
441        header_subtag(header_of(f)) == subtag_function) 
442#endif
443      {
444        nominal_function = f;
445      } else {
446      if (tra_f) {
447        nominal_function = tra_f;
448      }
449    }
450 
451  f = xpGPR(xp,Ifn);
452  if (object_contains_pc(f, abs_pc)) {
453    containing_uvector = untag(f)+fulltag_misc;
454  } else {
455    f = xpGPR(xp,Ixfn);
456    if (object_contains_pc(f, abs_pc)) {
457      containing_uvector = untag(f)+fulltag_misc;
458    } else {
459      if (tra_f) {
460        f = tra_f;
461        if (object_contains_pc(f, abs_pc)) {
462          containing_uvector = untag(f)+fulltag_misc;
463          relative_pc = (abs_pc - f) << fixnumshift;
464        }
465      }
466    }
467  }
468  if (containing_uvector) {
469    relative_pc = (abs_pc - (LispObj)&(deref(containing_uvector,1))) << fixnumshift;
470  } else {
471    containing_uvector = lisp_nil;
472    relative_pc = abs_pc << fixnumshift;
473  }
474  push_on_lisp_stack(xp,(LispObj)(tcr->xframe->prev));
475  push_on_lisp_stack(xp,(LispObj)(tcr->foreign_sp));
476  push_on_lisp_stack(xp,tra);
477  push_on_lisp_stack(xp,(LispObj)xp);
478  push_on_lisp_stack(xp,containing_uvector); 
479  push_on_lisp_stack(xp,relative_pc);
480  push_on_lisp_stack(xp,nominal_function);
481  push_on_lisp_stack(xp,0);
482#ifdef X8664
483  push_on_lisp_stack(xp,xpGPR(xp,Irbp));
484  xpGPR(xp,Irbp) = xpGPR(xp,Isp);
485#else
486  push_on_lisp_stack(xp,xpGPR(xp,Iebp));
487  xpGPR(xp,Iebp) = xpGPR(xp,Isp);
488#endif
489  return xpGPR(xp,Isp);
490}
491
492#ifndef XMEMFULL
493#define XMEMFULL (76)
494#endif
495
496void
497lisp_allocation_failure(ExceptionInformation *xp, TCR *tcr, natural bytes_needed )
498{
499  LispObj xcf = create_exception_callback_frame(xp, tcr),
500    cmain = nrs_CMAIN.vcell;
501  int skip;
502   
503  tcr->save_allocptr = tcr->save_allocbase = (void *)VOID_ALLOCPTR;
504  xpGPR(xp,Iallocptr) = VOID_ALLOCPTR;
505
506  skip = callback_to_lisp(tcr, cmain, xp, xcf, -1, XMEMFULL, 0, 0);
507  xpPC(xp) += skip;
508}
509
510/*
511  Allocate a large list, where "large" means "large enough to
512  possibly trigger the EGC several times if this was done
513  by individually allocating each CONS."  The number of
514  ocnses in question is in arg_z; on successful return,
515  the list will be in arg_z
516*/
517
518Boolean
519allocate_list(ExceptionInformation *xp, TCR *tcr)
520{
521  natural
522    nconses = (unbox_fixnum(xpGPR(xp,Iarg_z))),
523    bytes_needed = (nconses << dnode_shift);
524  LispObj
525    prev = lisp_nil,
526    current,
527    initial = xpGPR(xp,Iarg_y);
528
529  if (nconses == 0) {
530    /* Silly case */
531    xpGPR(xp,Iarg_z) = lisp_nil;
532    xpGPR(xp,Iallocptr) = lisp_nil;
533    return true;
534  }
535  update_bytes_allocated(tcr, (void *)(void *) tcr->save_allocptr);
536  if (allocate_object(xp,bytes_needed,bytes_needed-fulltag_cons,tcr)) {
537    tcr->save_allocptr -= fulltag_cons;
538    for (current = xpGPR(xp,Iallocptr);
539         nconses;
540         prev = current, current+= dnode_size, nconses--) {
541      deref(current,0) = prev;
542      deref(current,1) = initial;
543    }
544    xpGPR(xp,Iarg_z) = prev;
545  } else {
546    lisp_allocation_failure(xp,tcr,bytes_needed);
547  }
548  return true;
549}
550
551Boolean
552handle_alloc_trap(ExceptionInformation *xp, TCR *tcr)
553{
554  natural cur_allocptr, bytes_needed;
555  unsigned allocptr_tag;
556  signed_natural disp;
557 
558  cur_allocptr = xpGPR(xp,Iallocptr);
559  allocptr_tag = fulltag_of(cur_allocptr);
560  if (allocptr_tag == fulltag_misc) {
561#ifdef X8664
562    disp = xpGPR(xp,Iimm1);
563#else
564    disp = xpGPR(xp,Iimm0);
565#endif
566  } else {
567    disp = dnode_size-fulltag_cons;
568  }
569  bytes_needed = disp+allocptr_tag;
570
571  update_bytes_allocated(tcr,((BytePtr)(cur_allocptr+disp)));
572  if (allocate_object(xp, bytes_needed, disp, tcr)) {
573    return true;
574  }
575 
576  lisp_allocation_failure(xp,tcr,bytes_needed);
577
578  return true;
579}
580
581 
582int
583callback_to_lisp (TCR * tcr, LispObj callback_macptr, ExceptionInformation *xp,
584                  natural arg1, natural arg2, natural arg3, natural arg4, natural arg5)
585{
586  natural  callback_ptr;
587  int delta;
588  unsigned old_mxcsr = get_mxcsr();
589#ifdef X8632
590  natural saved_node_regs_mask = tcr->node_regs_mask;
591  LispObj *vsp = (LispObj *)xpGPR(xp, Isp);
592#endif
593
594  set_mxcsr(0x1f80);
595
596  /* Put the active stack pointers where .SPcallback expects them */
597#ifdef X8664
598  tcr->save_vsp = (LispObj *) xpGPR(xp, Isp);
599  tcr->save_rbp = (LispObj *) xpGPR(xp, Irbp);
600#else
601  tcr->node_regs_mask = X8632_DEFAULT_NODE_REGS_MASK;
602
603  *--vsp = tcr->save0;
604  *--vsp = tcr->save1;
605  *--vsp = tcr->save2;
606  *--vsp = tcr->save3;
607  *--vsp = tcr->next_method_context;
608  xpGPR(xp, Isp) = (LispObj)vsp;
609
610  tcr->save_vsp = (LispObj *)xpGPR(xp, Isp);
611  tcr->save_ebp = (LispObj *)xpGPR(xp, Iebp);
612#endif
613
614  /* Call back.  The caller of this function may have modified stack/frame
615     pointers (and at least should have called prepare_for_callback()).
616  */
617  callback_ptr = ((macptr *)ptr_from_lispobj(untag(callback_macptr)))->address;
618  UNLOCK(lisp_global(EXCEPTION_LOCK), tcr);
619  delta = ((int (*)())callback_ptr) (xp, arg1, arg2, arg3, arg4, arg5);
620  LOCK(lisp_global(EXCEPTION_LOCK), tcr);
621
622#ifdef X8632
623  tcr->next_method_context = *vsp++;
624  tcr->save3 = *vsp++;
625  tcr->save2 = *vsp++;
626  tcr->save1 = *vsp++;
627  tcr->save0 = *vsp++;
628  xpGPR(xp, Isp) = (LispObj)vsp;
629
630  tcr->node_regs_mask = saved_node_regs_mask;
631#endif
632  set_mxcsr(old_mxcsr);
633  return delta;
634}
635
636void
637callback_for_interrupt(TCR *tcr, ExceptionInformation *xp)
638{
639  LispObj *save_vsp = (LispObj *)xpGPR(xp,Isp),
640    word_beyond_vsp = save_vsp[-1],
641#ifdef X8664
642    save_rbp = xpGPR(xp,Irbp),
643#else
644    save_ebp = xpGPR(xp,Iebp),
645#endif
646    xcf = create_exception_callback_frame(xp, tcr);
647  int save_errno = errno;
648
649  callback_to_lisp(tcr, nrs_CMAIN.vcell,xp, xcf, 0, 0, 0, 0);
650#ifdef X8664
651  xpGPR(xp,Irbp) = save_rbp;
652#else
653  xpGPR(xp,Iebp) = save_ebp;
654#endif
655  xpGPR(xp,Isp) = (LispObj)save_vsp;
656  save_vsp[-1] = word_beyond_vsp;
657  errno = save_errno;
658}
659
660Boolean
661handle_error(TCR *tcr, ExceptionInformation *xp)
662{
663  pc program_counter = (pc)xpPC(xp);
664  unsigned char op0 = program_counter[0], op1 = program_counter[1];
665  LispObj rpc, errdisp = nrs_ERRDISP.vcell,
666    save_vsp = xpGPR(xp,Isp), xcf0;
667#ifdef X8664
668  LispObj save_rbp = xpGPR(xp,Irbp);
669#else
670  LispObj save_ebp = xpGPR(xp,Iebp);
671#endif
672  int skip;
673
674  if ((fulltag_of(errdisp) == fulltag_misc) &&
675      (header_subtag(header_of(errdisp)) == subtag_macptr)) {
676
677    if ((op0 == 0xcd) && (op1 >= 0xc0) && (op1 <= 0xc2)) {
678      finish_function_entry(xp);
679    }
680    xcf0 = create_exception_callback_frame(xp, tcr);
681    skip = callback_to_lisp(tcr, errdisp, xp, xcf0, 0, 0, 0, 0);
682    if (skip == -1) {
683      xcf *xcf1 = (xcf *)xcf0;
684      LispObj container = xcf1->containing_uvector;
685     
686      rpc = xcf1->relative_pc >> fixnumshift;
687      if (container == lisp_nil) {
688        xpPC(xp) = rpc;
689      } else {
690        xpPC(xp) = (LispObj)(&(deref(container,
691#ifdef X8664
692                                     1
693#else
694                                     0
695#endif
696)))+rpc;
697      }
698       
699      skip = 0;
700    }
701#ifdef X8664
702    xpGPR(xp,Irbp) = save_rbp;
703#else
704    xpGPR(xp,Iebp) = save_ebp;
705#endif
706    xpGPR(xp,Isp) = save_vsp;
707    if ((op0 == 0xcd) && (op1 == 0xc7)) {
708      /* Continue after an undefined function call. The function
709         that had been undefined has already been called (in the
710         break loop), and a list of the values that it returned
711         in in the xp's %arg_z.  A function that returns those
712         values in in the xp's %fn; we just have to adjust the
713         stack (keeping the return address in the right place
714         and discarding any stack args/reserved stack frame),
715         then set nargs and the PC so that that function's
716         called when we resume.
717      */
718      LispObj *vsp =(LispObj *)save_vsp, ra = *vsp;
719#ifdef X8664
720      int nargs = (xpGPR(xp, Inargs) & 0xffff)>>fixnumshift;
721#else
722      int nargs = xpGPR(xp, Inargs)>>fixnumshift;
723#endif
724
725#ifdef X8664
726      if (nargs > 3) {
727        xpGPR(xp,Isp)=(LispObj) (vsp + (1 + 2 + (nargs - 3)));
728        push_on_lisp_stack(xp,ra);
729      }
730#else
731      if (nargs > 2) {
732        xpGPR(xp,Isp)=(LispObj) (vsp + (1 + 2 + (nargs - 2)));
733        push_on_lisp_stack(xp,ra);
734      }
735#endif
736      xpPC(xp) = xpGPR(xp,Ifn);
737      xpGPR(xp,Inargs) = 1<<fixnumshift;
738    } else {
739      xpPC(xp) += skip;
740    }
741    return true;
742  } else {
743    return false;
744  }
745}
746
747
748protection_handler
749* protection_handlers[] = {
750  do_spurious_wp_fault,
751  do_soft_stack_overflow,
752  do_soft_stack_overflow,
753  do_soft_stack_overflow,
754  do_hard_stack_overflow,   
755  do_hard_stack_overflow,
756  do_hard_stack_overflow,
757};
758
759
760/* Maybe this'll work someday.  We may have to do something to
761   make the thread look like it's not handling an exception */
762void
763reset_lisp_process(ExceptionInformation *xp)
764{
765}
766
767Boolean
768do_hard_stack_overflow(ExceptionInformation *xp, protected_area_ptr area, BytePtr addr)
769{
770  reset_lisp_process(xp);
771  return false;
772}
773
774
775Boolean
776do_spurious_wp_fault(ExceptionInformation *xp, protected_area_ptr area, BytePtr addr)
777{
778
779  return false;
780}
781
782Boolean
783do_soft_stack_overflow(ExceptionInformation *xp, protected_area_ptr prot_area, BytePtr addr)
784{
785  /* Trying to write into a guard page on the vstack or tstack.
786     Allocate a new stack segment, emulate stwu and stwux for the TSP, and
787     signal an error_stack_overflow condition.
788      */
789  lisp_protection_kind which = prot_area->why;
790  Boolean on_TSP = (which == kTSPsoftguard);
791#ifdef X8664
792  LispObj save_rbp = xpGPR(xp,Irbp);
793#else
794  LispObj save_ebp = xpGPR(xp,Iebp);
795#endif
796  LispObj save_vsp = xpGPR(xp,Isp), 
797    xcf,
798    cmain = nrs_CMAIN.vcell;
799  area *a;
800  protected_area_ptr soft;
801  TCR *tcr = get_tcr(false);
802  int skip;
803
804  if ((fulltag_of(cmain) == fulltag_misc) &&
805      (header_subtag(header_of(cmain)) == subtag_macptr)) {
806    if (on_TSP) {
807      a = tcr->ts_area;
808    } else {
809      a = tcr->vs_area;
810    }
811    soft = a->softprot;
812    unprotect_area(soft);
813    xcf = create_exception_callback_frame(xp, tcr);
814    skip = callback_to_lisp(tcr, nrs_CMAIN.vcell, xp, xcf, SIGSEGV, on_TSP, 0, 0);
815#ifdef X8664
816    xpGPR(xp,Irbp) = save_rbp;
817#else
818    xpGPR(xp,Iebp) = save_ebp;
819#endif
820    xpGPR(xp,Isp) = save_vsp;
821    xpPC(xp) += skip;
822    return true;
823  }
824  return false;
825}
826
827Boolean
828is_write_fault(ExceptionInformation *xp, siginfo_t *info)
829{
830#ifdef DARWIN
831#ifdef X8664
832  return (UC_MCONTEXT(xp)->__es.__err & 0x2) != 0;
833#else
834  return (xp->uc_mcontext->__es.__err & 0x2) != 0;
835#endif
836#endif
837#if defined(LINUX) || defined(SOLARIS)
838  return (xpGPR(xp,REG_ERR) & 0x2) != 0;
839#endif
840#ifdef FREEBSD
841  return (xp->uc_mcontext.mc_err & 0x2) != 0;
842#endif
843#ifdef WINDOWS
844  return (info->ExceptionFlags == EXCEPTION_WRITE_FAULT);
845#endif
846}
847
848Boolean
849handle_fault(TCR *tcr, ExceptionInformation *xp, siginfo_t *info, int old_valence)
850{
851#ifdef FREEBSD
852#ifdef X8664
853  BytePtr addr = (BytePtr) xp->uc_mcontext.mc_addr;
854#else
855  BytePtr addr = (BytePtr) info->si_addr;
856#endif
857#else
858#ifdef WINDOWS
859  BytePtr addr = (BytePtr) info->ExceptionInformation[1];
860#else
861  BytePtr addr = (BytePtr) info->si_addr;
862#endif
863#endif
864
865
866  if (addr && (addr == tcr->safe_ref_address)) {
867    xpGPR(xp,Iimm0) = 0;
868    xpPC(xp) = xpGPR(xp,Ira0);
869    return true;
870  } else {
871    protected_area *a = find_protected_area(addr);
872    protection_handler *handler;
873
874    if (a) {
875      handler = protection_handlers[a->why];
876      return handler(xp, a, addr);
877    } else {
878      if ((addr >= readonly_area->low) &&
879          (addr < readonly_area->active)) {
880        UnProtectMemory((LogicalAddress)(truncate_to_power_of_2(addr,log2_page_size)),
881                        page_size);
882        return true;
883      }
884    }
885  }
886  if (old_valence == TCR_STATE_LISP) {
887    LispObj cmain = nrs_CMAIN.vcell,
888      xcf;
889    if ((fulltag_of(cmain) == fulltag_misc) &&
890      (header_subtag(header_of(cmain)) == subtag_macptr)) {
891      xcf = create_exception_callback_frame(xp, tcr);
892      callback_to_lisp(tcr, cmain, xp, xcf, SIGBUS, is_write_fault(xp,info), (natural)addr, 0);
893    }
894  }
895  return false;
896}
897
898Boolean
899handle_floating_point_exception(TCR *tcr, ExceptionInformation *xp, siginfo_t *info)
900{
901  int code,skip;
902  LispObj  xcf, cmain = nrs_CMAIN.vcell,
903    save_vsp = xpGPR(xp,Isp);
904#ifdef X8664
905  LispObj save_rbp = xpGPR(xp,Irbp);
906#else
907  LispObj save_ebp = xpGPR(xp,Iebp);
908#endif
909#ifdef WINDOWS
910  code = info->ExceptionCode;
911#else
912  code = info->si_code;
913#endif 
914
915  if ((fulltag_of(cmain) == fulltag_misc) &&
916      (header_subtag(header_of(cmain)) == subtag_macptr)) {
917    xcf = create_exception_callback_frame(xp, tcr);
918    skip = callback_to_lisp(tcr, cmain, xp, xcf, SIGFPE, code, 0, 0);
919    xpPC(xp) += skip;
920#ifdef X8664
921    xpGPR(xp,Irbp) = save_rbp;
922#else
923    xpGPR(xp,Iebp) = save_ebp;
924#endif
925    xpGPR(xp,Isp) = save_vsp;
926    return true;
927  } else {
928    return false;
929  }
930}
931
932
933Boolean
934extend_tcr_tlb(TCR *tcr, ExceptionInformation *xp)
935{
936  LispObj index, old_limit = tcr->tlb_limit, new_limit, new_bytes;
937  LispObj *old_tlb = tcr->tlb_pointer, *new_tlb, *work, *tos;
938
939  tos = (LispObj*)(xpGPR(xp,Isp));
940  index = *tos++;
941  (xpGPR(xp,Isp))=(LispObj)tos;
942 
943  new_limit = align_to_power_of_2(index+1,12);
944  new_bytes = new_limit-old_limit;
945  new_tlb = realloc(old_tlb, new_limit);
946
947  if (new_tlb == NULL) {
948    return false;
949  }
950  work = (LispObj *) ((BytePtr)new_tlb+old_limit);
951
952  while (new_bytes) {
953    *work++ = no_thread_local_binding_marker;
954    new_bytes -= sizeof(LispObj);
955  }
956  tcr->tlb_pointer = new_tlb;
957  tcr->tlb_limit = new_limit;
958  return true;
959}
960
961
962#if defined(FREEBSD) || defined(DARWIN)
963static
964char mxcsr_bit_to_fpe_code[] = {
965  FPE_FLTINV,                   /* ie */
966  0,                            /* de */
967  FPE_FLTDIV,                   /* ze */
968  FPE_FLTOVF,                   /* oe */
969  FPE_FLTUND,                   /* ue */
970  FPE_FLTRES                    /* pe */
971};
972
973void
974decode_vector_fp_exception(siginfo_t *info, uint32_t mxcsr)
975{
976  /* If the exception appears to be an XMM FP exception, try to
977     determine what it was by looking at bits in the mxcsr.
978  */
979  int xbit, maskbit;
980 
981  for (xbit = 0, maskbit = MXCSR_IM_BIT; xbit < 6; xbit++, maskbit++) {
982    if ((mxcsr & (1 << xbit)) &&
983        !(mxcsr & (1 << maskbit))) {
984      info->si_code = mxcsr_bit_to_fpe_code[xbit];
985      return;
986    }
987  }
988}
989
990#ifdef FREEBSD
991void
992freebsd_decode_vector_fp_exception(siginfo_t *info, ExceptionInformation *xp)
993{
994  if (info->si_code == 0) {
995#ifdef X8664
996    struct savefpu *fpu = (struct savefpu *) &(xp->uc_mcontext.mc_fpstate);
997#else
998    struct ccl_savexmm *fpu = (struct ccl_savexmm *) &(xp->uc_mcontext.mc_fpstate);
999#endif
1000    uint32_t mxcsr = fpu->sv_env.en_mxcsr;
1001
1002    decode_vector_fp_exception(info, mxcsr);
1003  }
1004}
1005#endif
1006
1007#ifdef DARWIN
1008void
1009darwin_decode_vector_fp_exception(siginfo_t *info, ExceptionInformation *xp)
1010{
1011  if (info->si_code == EXC_I386_SSEEXTERR) {
1012    uint32_t mxcsr = UC_MCONTEXT(xp)->__fs.__fpu_mxcsr;
1013
1014    decode_vector_fp_exception(info, mxcsr);
1015  }
1016}
1017
1018#endif
1019
1020#endif
1021
1022void
1023get_lisp_string(LispObj lisp_string, char *c_string, natural max)
1024{
1025  lisp_char_code *src = (lisp_char_code *)  (ptr_from_lispobj(lisp_string + misc_data_offset));
1026  natural i, n = header_element_count(header_of(lisp_string));
1027
1028  if (n > max) {
1029    n = max;
1030  }
1031
1032  for (i = 0; i < n; i++) {
1033    c_string[i] = 0xff & (src[i]);
1034  }
1035  c_string[n] = 0;
1036}
1037
1038Boolean
1039handle_exception(int signum, siginfo_t *info, ExceptionInformation  *context, TCR *tcr, int old_valence)
1040{
1041  pc program_counter = (pc)xpPC(context);
1042
1043  switch (signum) {
1044  case SIGNUM_FOR_INTN_TRAP:
1045    if (IS_MAYBE_INT_TRAP(info,context)) {
1046      /* Something mapped to SIGSEGV/SIGBUS that has nothing to do with
1047         a memory fault.  On x86, an "int n" instruction that's
1048         not otherwise implemented causes a "protecton fault".  Of
1049         course that has nothing to do with accessing protected
1050         memory; of course, most Unices act as if it did.*/
1051      if ((program_counter != NULL) &&
1052          (*program_counter == INTN_OPCODE)) {
1053        program_counter++;
1054        switch (*program_counter) {
1055        case UUO_ALLOC_TRAP:
1056          if (handle_alloc_trap(context, tcr)) {
1057            xpPC(context) += 2; /* we might have GCed. */
1058            return true;
1059          }
1060          break;
1061        case UUO_GC_TRAP:
1062          if (handle_gc_trap(context, tcr)) {
1063            xpPC(context) += 2;
1064            return true;
1065          }
1066          break;
1067           
1068        case UUO_DEBUG_TRAP:
1069          xpPC(context) = (natural) (program_counter+1);
1070          lisp_Debugger(context, info, debug_entry_dbg, false, "Lisp Breakpoint");
1071          return true;
1072           
1073        case UUO_DEBUG_TRAP_WITH_STRING:
1074          xpPC(context) = (natural) (program_counter+1);
1075          {
1076            char msg[512];
1077
1078            get_lisp_string(xpGPR(context,Iarg_z),msg, sizeof(msg)-1);
1079            lisp_Debugger(context, info, debug_entry_dbg, false, msg);
1080          }
1081          return true;
1082         
1083        default:
1084          return handle_error(tcr, context);
1085        }
1086      } else {
1087        return false;
1088      }
1089
1090    } else {
1091      return handle_fault(tcr, context, info, old_valence);
1092    }
1093    break;
1094
1095  case SIGNAL_FOR_PROCESS_INTERRUPT:
1096    tcr->interrupt_pending = 0;
1097    callback_for_interrupt(tcr, context);
1098    return true;
1099    break;
1100
1101
1102  case SIGILL:
1103    if ((program_counter[0] == XUUO_OPCODE_0) &&
1104        (program_counter[1] == XUUO_OPCODE_1)) {
1105      TCR *target = (TCR *)xpGPR(context, Iarg_z);
1106
1107      switch (program_counter[2]) {
1108      case XUUO_TLB_TOO_SMALL:
1109        if (extend_tcr_tlb(tcr,context)) {
1110          xpPC(context)+=3;
1111          return true;
1112        }
1113        break;
1114       
1115      case XUUO_INTERRUPT_NOW:
1116        callback_for_interrupt(tcr,context);
1117        xpPC(context)+=3;
1118        return true;
1119
1120      case XUUO_SUSPEND_NOW:
1121        xpPC(context)+=3;
1122        return true;
1123
1124      case XUUO_INTERRUPT:
1125        raise_thread_interrupt(target);
1126        xpPC(context)+=3;
1127        return true;
1128
1129      case XUUO_SUSPEND:
1130        xpGPR(context,Iimm0) = (LispObj) lisp_suspend_tcr(target);
1131        xpPC(context)+=3;
1132        return true;
1133
1134      case XUUO_SUSPEND_ALL:
1135        lisp_suspend_other_threads();
1136        xpPC(context)+=3;
1137        return true;
1138
1139
1140      case XUUO_RESUME:
1141        xpGPR(context,Iimm0) = (LispObj) lisp_resume_tcr(target);
1142        xpPC(context)+=3;
1143        return true;
1144       
1145      case XUUO_RESUME_ALL:
1146        lisp_resume_other_threads();
1147        xpPC(context)+=3;
1148        return true;
1149       
1150      case XUUO_KILL:
1151        xpGPR(context,Iimm0) = (LispObj)kill_tcr(target);
1152        xpPC(context)+=3;
1153        return true;
1154
1155      case XUUO_ALLOCATE_LIST:
1156        allocate_list(context,tcr);
1157        xpPC(context)+=3;
1158        return true;
1159
1160      default:
1161        return false;
1162      }
1163    } else {
1164      return false;
1165    }
1166    break;
1167   
1168  case SIGFPE:
1169#ifdef FREEBSD
1170    /* As of 6.1, FreeBSD/AMD64 doesn't seem real comfortable
1171       with this newfangled XMM business (and therefore info->si_code
1172       is often 0 on an XMM FP exception.
1173       Try to figure out what really happened by decoding mxcsr
1174       bits.
1175    */
1176    freebsd_decode_vector_fp_exception(info,context);
1177#endif
1178#ifdef DARWIN
1179    /* Same general problem with Darwin as of 8.7.2 */
1180    darwin_decode_vector_fp_exception(info,context);
1181#endif
1182
1183    return handle_floating_point_exception(tcr, context, info);
1184
1185#if SIGBUS != SIGNUM_FOR_INTN_TRAP
1186  case SIGBUS:
1187    return handle_fault(tcr, context, info, old_valence);
1188#endif
1189   
1190#if SIGSEGV != SIGNUM_FOR_INTN_TRAP
1191  case SIGSEGV:
1192    return handle_fault(tcr, context, info, old_valence);
1193#endif   
1194   
1195  default:
1196    return false;
1197  }
1198}
1199
1200
1201/*
1202   Current thread has all signals masked.  Before unmasking them,
1203   make it appear that the current thread has been suspended.
1204   (This is to handle the case where another thread is trying
1205   to GC before this thread is able to seize the exception lock.)
1206*/
1207int
1208prepare_to_wait_for_exception_lock(TCR *tcr, ExceptionInformation *context)
1209{
1210  int old_valence = tcr->valence;
1211
1212  tcr->pending_exception_context = context;
1213  tcr->valence = TCR_STATE_EXCEPTION_WAIT;
1214
1215#ifdef WINDOWS
1216  if (tcr->flags & (1<<TCR_FLAG_BIT_PENDING_SUSPEND)) {
1217    CLR_TCR_FLAG(tcr, TCR_FLAG_BIT_PENDING_SUSPEND);
1218    SEM_RAISE(tcr->suspend);
1219    SEM_WAIT_FOREVER(tcr->resume);
1220  }
1221#else
1222  ALLOW_EXCEPTIONS(context);
1223#endif
1224  return old_valence;
1225} 
1226
1227void
1228wait_for_exception_lock_in_handler(TCR *tcr, 
1229                                   ExceptionInformation *context,
1230                                   xframe_list *xf)
1231{
1232
1233  LOCK(lisp_global(EXCEPTION_LOCK), tcr);
1234#if 0
1235  fprintf(dbgout, "0x" LISP " has exception lock\n", tcr);
1236#endif
1237  xf->curr = context;
1238#ifdef X8632
1239  xf->node_regs_mask = tcr->node_regs_mask;
1240#endif
1241  xf->prev = tcr->xframe;
1242  tcr->xframe =  xf;
1243  tcr->pending_exception_context = NULL;
1244  tcr->valence = TCR_STATE_FOREIGN; 
1245}
1246
1247void
1248unlock_exception_lock_in_handler(TCR *tcr)
1249{
1250  tcr->pending_exception_context = tcr->xframe->curr;
1251#ifdef X8632
1252  tcr->node_regs_mask = tcr->xframe->node_regs_mask;
1253#endif
1254  tcr->xframe = tcr->xframe->prev;
1255  tcr->valence = TCR_STATE_EXCEPTION_RETURN;
1256  UNLOCK(lisp_global(EXCEPTION_LOCK),tcr);
1257#if 0
1258  fprintf(dbgout, "0x" LISP " released exception lock\n", tcr);
1259#endif
1260}
1261
1262/*
1263   If an interrupt is pending on exception exit, try to ensure
1264   that the thread sees it as soon as it's able to run.
1265*/
1266#ifdef WINDOWS
1267void
1268raise_pending_interrupt(TCR *tcr)
1269{
1270}
1271void
1272exit_signal_handler(TCR *tcr, int old_valence)
1273{
1274}
1275void
1276signal_handler(int signum, siginfo_t *info, ExceptionInformation  *context, TCR *tcr, int old_valence)
1277{
1278}
1279#else
1280void
1281raise_pending_interrupt(TCR *tcr)
1282{
1283  if ((TCR_INTERRUPT_LEVEL(tcr) >= 0) &&
1284      (tcr->interrupt_pending)) {
1285    pthread_kill((pthread_t)(tcr->osid), SIGNAL_FOR_PROCESS_INTERRUPT);
1286  }
1287}
1288
1289void
1290exit_signal_handler(TCR *tcr, int old_valence)
1291{
1292  sigset_t mask;
1293  sigfillset(&mask);
1294#ifdef FREEBSD
1295  sigdelset(&mask,SIGTRAP);
1296#endif
1297 
1298  pthread_sigmask(SIG_SETMASK,&mask, NULL);
1299  tcr->valence = old_valence;
1300  tcr->pending_exception_context = NULL;
1301}
1302
1303void
1304signal_handler(int signum, siginfo_t *info, ExceptionInformation  *context
1305#ifdef DARWIN
1306               , TCR *tcr, int old_valence
1307#endif
1308)
1309{
1310#ifdef DARWIN_GS_HACK
1311  Boolean gs_was_tcr = ensure_gs_pthread();
1312#endif
1313  xframe_list xframe_link;
1314#ifndef DARWIN
1315  TCR *tcr = get_tcr(false);
1316
1317  int old_valence = prepare_to_wait_for_exception_lock(tcr, context);
1318#endif
1319  if (tcr->flags & (1<<TCR_FLAG_BIT_PENDING_SUSPEND)) {
1320    CLR_TCR_FLAG(tcr, TCR_FLAG_BIT_PENDING_SUSPEND);
1321    pthread_kill(pthread_self(), thread_suspend_signal);
1322  }
1323  wait_for_exception_lock_in_handler(tcr,context, &xframe_link);
1324
1325
1326  if (! handle_exception(signum, info, context, tcr, old_valence)) {
1327    char msg[512];
1328    Boolean foreign = (old_valence != TCR_STATE_LISP);
1329
1330    snprintf(msg, sizeof(msg), "Unhandled exception %d at 0x" LISP ", context->regs at #x" LISP "", signum, xpPC(context), (natural)xpGPRvector(context));
1331   
1332    if (lisp_Debugger(context, info, signum,  foreign, msg)) {
1333      SET_TCR_FLAG(tcr,TCR_FLAG_BIT_PROPAGATE_EXCEPTION);
1334    }
1335  }
1336  unlock_exception_lock_in_handler(tcr);
1337#ifndef DARWIN_USE_PSEUDO_SIGRETURN
1338  exit_signal_handler(tcr, old_valence);
1339#endif
1340  /* raise_pending_interrupt(tcr); */
1341#ifdef DARWIN_GS_HACK
1342  if (gs_was_tcr) {
1343    set_gs_address(tcr);
1344  }
1345#endif
1346#ifndef DARWIN_USE_PSEUDO_SIGRETURN
1347  SIGRETURN(context);
1348#endif
1349}
1350#endif
1351
1352
1353
1354
1355#ifdef LINUX
1356/* type of pointer to saved fp state */
1357#ifdef X8664
1358typedef fpregset_t FPREGS;
1359#else
1360typedef struct _fpstate *FPREGS;
1361#endif
1362LispObj *
1363copy_fpregs(ExceptionInformation *xp, LispObj *current, FPREGS *destptr)
1364{
1365  FPREGS src = (FPREGS)(xp->uc_mcontext.fpregs), dest;
1366 
1367  if (src) {
1368    dest = ((FPREGS)current)-1;
1369    *dest = *src;
1370    *destptr = dest;
1371    current = (LispObj *) dest;
1372  }
1373  return current;
1374}
1375#endif
1376
1377#ifdef DARWIN
1378LispObj *
1379copy_darwin_mcontext(MCONTEXT_T context, 
1380                     LispObj *current, 
1381                     MCONTEXT_T *out)
1382{
1383  MCONTEXT_T dest = ((MCONTEXT_T)current)-1;
1384  dest = (MCONTEXT_T) (((LispObj)dest) & ~15);
1385
1386  *dest = *context;
1387  *out = dest;
1388  return (LispObj *)dest;
1389}
1390#endif
1391
1392LispObj *
1393copy_siginfo(siginfo_t *info, LispObj *current)
1394{
1395  siginfo_t *dest = ((siginfo_t *)current) - 1;
1396#if !defined(LINUX) || !defined(X8632)
1397  dest = (siginfo_t *) (((LispObj)dest)&~15);
1398#endif
1399  *dest = *info;
1400  return (LispObj *)dest;
1401}
1402
1403#ifdef LINUX
1404typedef FPREGS copy_ucontext_last_arg_t;
1405#else
1406typedef void * copy_ucontext_last_arg_t;
1407#endif
1408
1409#ifndef WINDOWS
1410LispObj *
1411copy_ucontext(ExceptionInformation *context, LispObj *current, copy_ucontext_last_arg_t fp)
1412{
1413  ExceptionInformation *dest = ((ExceptionInformation *)current)-1;
1414#if !defined(LINUX) || !defined(X8632)
1415  dest = (ExceptionInformation *) (((LispObj)dest) & ~15);
1416#endif
1417
1418  *dest = *context;
1419  /* Fix it up a little; where's the signal mask allocated, if indeed
1420     it is "allocated" ? */
1421#ifdef LINUX
1422  dest->uc_mcontext.fpregs = (fpregset_t)fp;
1423#endif
1424  dest->uc_stack.ss_sp = 0;
1425  dest->uc_stack.ss_size = 0;
1426  dest->uc_stack.ss_flags = 0;
1427  dest->uc_link = NULL;
1428  return (LispObj *)dest;
1429}
1430#endif
1431
1432
1433LispObj *
1434tcr_frame_ptr(TCR *tcr)
1435{
1436  ExceptionInformation *xp;
1437  LispObj *bp;
1438
1439  if (tcr->pending_exception_context)
1440    xp = tcr->pending_exception_context;
1441  else if (tcr->valence == TCR_STATE_LISP) {
1442    xp = tcr->suspend_context;
1443  } else {
1444    xp = NULL;
1445  }
1446  if (xp) {
1447#ifdef X8664
1448    bp = (LispObj *) xpGPR(xp, Irbp);
1449#else
1450    bp = (LispObj *) xpGPR(xp, Iebp);
1451#endif
1452  } else {
1453#ifdef X8664
1454    bp = tcr->save_rbp;
1455#else
1456    bp = tcr->save_ebp;
1457#endif
1458  }
1459  return bp;
1460}
1461
1462
1463LispObj *
1464find_foreign_rsp(LispObj rsp, area *foreign_area, TCR *tcr)
1465{
1466
1467  if (((BytePtr)rsp < foreign_area->low) ||
1468      ((BytePtr)rsp > foreign_area->high)) {
1469    rsp = (LispObj)(tcr->foreign_sp);
1470  }
1471  return (LispObj *) (((rsp-128) & ~15));
1472}
1473
1474#ifdef X8632
1475#ifdef LINUX
1476/* This is here for debugging.  On entry to a signal handler that
1477   receives info and context arguments, the stack should look exactly
1478   like this.  The "pretcode field" of the structure is the address
1479   of code that does an rt_sigreturn syscall, and rt_sigreturn expects
1480   %esp at the time of that syscall to be pointing just past the
1481   pretcode field.
1482   handle_signal_on_foreign_stack() and helpers have to be very
1483   careful to duplicate this "structure" exactly.
1484   Note that on x8664 Linux, rt_sigreturn expects a ucontext to
1485   be on top of the stack (with a siginfo_t underneath it.)
1486   It sort of half-works to do sigreturn via setcontext() on
1487   x8632 Linux, but (a) it may not be available on some distributions
1488   and (b) even a relatively modern version of it uses "fldenv" to
1489   restore FP context, and "fldenv" isn't nearly good enough.
1490*/
1491
1492struct rt_sigframe {
1493        char *pretcode;
1494        int sig;
1495        siginfo_t  *pinfo;
1496        void  *puc;
1497        siginfo_t info;
1498        struct ucontext uc;
1499        struct _fpstate fpstate;
1500        char retcode[8];
1501};
1502struct rt_sigframe *rtsf = 0;
1503
1504#endif
1505#endif
1506
1507
1508#ifndef WINDOWS
1509/* x8632 Linux requires that the stack-allocated siginfo is nearer
1510   the top of stack than the stack-allocated ucontext.  If other
1511   platforms care, they expect the ucontext to be nearer the top
1512   of stack.
1513*/
1514
1515#if defined(LINUX) && defined(X8632)
1516#define UCONTEXT_ON_TOP_OF_STACK 0
1517#else
1518#define UCONTEXT_ON_TOP_OF_STACK 1
1519#endif
1520void
1521handle_signal_on_foreign_stack(TCR *tcr,
1522                               void *handler, 
1523                               int signum, 
1524                               siginfo_t *info, 
1525                               ExceptionInformation *context,
1526                               LispObj return_address
1527#ifdef DARWIN_GS_HACK
1528                               , Boolean gs_was_tcr
1529#endif
1530                               )
1531{
1532#ifdef LINUX
1533  FPREGS fpregs = NULL;
1534#else
1535  void *fpregs = NULL;
1536#endif
1537#ifdef DARWIN
1538  MCONTEXT_T mcontextp = NULL;
1539#endif
1540  siginfo_t *info_copy = NULL;
1541  ExceptionInformation *xp = NULL;
1542  LispObj *foreign_rsp = find_foreign_rsp(xpGPR(context,Isp), tcr->cs_area, tcr);
1543
1544#ifdef LINUX
1545  foreign_rsp = copy_fpregs(context, foreign_rsp, &fpregs);
1546#endif
1547#ifdef DARWIN
1548  foreign_rsp = copy_darwin_mcontext(UC_MCONTEXT(context), foreign_rsp, &mcontextp);
1549#endif
1550#if UCONTEXT_ON_TOP_OF_STACK
1551  /* copy info first */
1552  foreign_rsp = copy_siginfo(info, foreign_rsp);
1553  info_copy = (siginfo_t *)foreign_rsp;
1554  foreign_rsp = copy_ucontext(context, foreign_rsp, fpregs);
1555  xp = (ExceptionInformation *)foreign_rsp;
1556#else
1557  foreign_rsp = copy_ucontext(context, foreign_rsp, fpregs);
1558  xp = (ExceptionInformation *)foreign_rsp;
1559  foreign_rsp = copy_siginfo(info, foreign_rsp);
1560  info_copy = (siginfo_t *)foreign_rsp;
1561#endif
1562#ifdef DARWIN
1563  UC_MCONTEXT(xp) = mcontextp;
1564#endif
1565  *--foreign_rsp = return_address;
1566#ifdef DARWIN_GS_HACK
1567  if (gs_was_tcr) {
1568    set_gs_address(tcr);
1569  }
1570#endif
1571  switch_to_foreign_stack(foreign_rsp,handler,signum,info_copy,xp);
1572}
1573#endif
1574
1575
1576#ifndef WINDOWS
1577#ifndef USE_SIGALTSTACK
1578void
1579arbstack_signal_handler(int signum, siginfo_t *info, ExceptionInformation *context)
1580{
1581  TCR *tcr = get_interrupt_tcr(false);
1582#if 1
1583  if (tcr->valence != TCR_STATE_LISP) {
1584    FBug(context, "exception in foreign context");
1585  }
1586#endif
1587  {
1588    area *vs = tcr->vs_area;
1589    BytePtr current_sp = (BytePtr) current_stack_pointer();
1590
1591
1592    if ((current_sp >= vs->low) &&
1593        (current_sp < vs->high)) {
1594      handle_signal_on_foreign_stack(tcr,
1595                                     signal_handler,
1596                                     signum,
1597                                     info,
1598                                     context,
1599                                     (LispObj)__builtin_return_address(0)
1600#ifdef DARWIN_GS_HACK
1601                                     , false
1602#endif
1603
1604                                     );
1605    } else {
1606      signal_handler(signum, info, context, tcr, 0);
1607    }
1608  }
1609}
1610
1611#else
1612void
1613altstack_signal_handler(int signum, siginfo_t *info, ExceptionInformation  *context)
1614{
1615  TCR* tcr = get_tcr(true);
1616#if 1
1617  if (tcr->valence != TCR_STATE_LISP) {
1618    FBug(context, "exception in foreign context");
1619  }
1620#endif
1621  handle_signal_on_foreign_stack(tcr,signal_handler,signum,info,context,(LispObj)__builtin_return_address(0)
1622#ifdef DARWIN_GS_HACK
1623                                 , false
1624#endif
1625);
1626}
1627#endif
1628#endif
1629
1630Boolean
1631stack_pointer_on_vstack_p(LispObj stack_pointer, TCR *tcr)
1632{
1633  area *a = tcr->vs_area;
1634 
1635  return (((BytePtr)stack_pointer <= a->high) &&
1636          ((BytePtr)stack_pointer > a->low));
1637}
1638
1639
1640#ifdef WINDOWS
1641extern DWORD restore_windows_context(ExceptionInformation *, TCR *, int);
1642#endif
1643
1644void
1645interrupt_handler (int signum, siginfo_t *info, ExceptionInformation *context)
1646{
1647#ifdef DARWIN_GS_HACK
1648  Boolean gs_was_tcr = ensure_gs_pthread();
1649#endif
1650  TCR *tcr = get_interrupt_tcr(false);
1651  int old_valence = tcr->valence;
1652
1653  if (tcr) {
1654    if ((TCR_INTERRUPT_LEVEL(tcr) < 0) ||
1655        (tcr->valence != TCR_STATE_LISP) ||
1656        (tcr->unwinding != 0) ||
1657        ! stack_pointer_on_vstack_p(xpGPR(context,Isp), tcr) ||
1658#ifdef X8664
1659        ! stack_pointer_on_vstack_p(xpGPR(context,Irbp), tcr)) {
1660#else
1661        ! stack_pointer_on_vstack_p(xpGPR(context,Iebp), tcr)) {
1662#endif
1663      tcr->interrupt_pending = (((natural) 1)<< (nbits_in_word - ((natural)1)));
1664    } else {
1665      LispObj cmain = nrs_CMAIN.vcell;
1666
1667      if ((fulltag_of(cmain) == fulltag_misc) &&
1668          (header_subtag(header_of(cmain)) == subtag_macptr)) {
1669        /*
1670           This thread can (allegedly) take an interrupt now.
1671        */
1672
1673        xframe_list xframe_link;
1674        signed_natural alloc_displacement = 0;
1675        LispObj
1676          *next_tsp = tcr->next_tsp,
1677          *save_tsp = tcr->save_tsp,
1678          *p,
1679          q;
1680        natural old_foreign_exception = tcr->flags & (1 << TCR_FLAG_BIT_FOREIGN_EXCEPTION);
1681
1682        tcr->flags &= ~(1 << TCR_FLAG_BIT_FOREIGN_EXCEPTION);
1683           
1684        if (next_tsp != save_tsp) {
1685          tcr->next_tsp = save_tsp;
1686        } else {
1687          next_tsp = NULL;
1688        }
1689        /* have to do this before allowing interrupts */
1690        pc_luser_xp(context, tcr, &alloc_displacement);
1691        old_valence = prepare_to_wait_for_exception_lock(tcr, context);
1692        wait_for_exception_lock_in_handler(tcr, context, &xframe_link);
1693        handle_exception(signum, info, context, tcr, old_valence);
1694        if (alloc_displacement) {
1695          tcr->save_allocptr -= alloc_displacement;
1696        }
1697        if (next_tsp) {
1698          tcr->next_tsp = next_tsp;
1699          p = next_tsp;
1700          while (p != save_tsp) {
1701            *p++ = 0;
1702          }
1703          q = (LispObj)save_tsp;
1704          *next_tsp = q;
1705        }
1706        tcr->flags |= old_foreign_exception;
1707        unlock_exception_lock_in_handler(tcr);
1708#ifndef WINDOWS
1709        exit_signal_handler(tcr, old_valence);
1710#endif
1711      }
1712    }
1713  }
1714#ifdef DARWIN_GS_HACK
1715  if (gs_was_tcr) {
1716    set_gs_address(tcr);
1717  }
1718#endif
1719#ifdef WINDOWS
1720  restore_windows_context(context,tcr,old_valence);
1721#else
1722  SIGRETURN(context);
1723#endif
1724}
1725
1726
1727#ifndef WINDOWS
1728#ifndef USE_SIGALTSTACK
1729void
1730arbstack_interrupt_handler (int signum, siginfo_t *info, ExceptionInformation *context)
1731{
1732#ifdef DARWIN_GS_HACK
1733  Boolean gs_was_tcr = ensure_gs_pthread();
1734#endif
1735  TCR *tcr = get_interrupt_tcr(false);
1736  area *vs = tcr->vs_area;
1737  BytePtr current_sp = (BytePtr) current_stack_pointer();
1738
1739  if ((current_sp >= vs->low) &&
1740      (current_sp < vs->high)) {
1741    handle_signal_on_foreign_stack(tcr,
1742                                   interrupt_handler,
1743                                   signum,
1744                                   info,
1745                                   context,
1746                                   (LispObj)__builtin_return_address(0)
1747#ifdef DARWIN_GS_HACK
1748                                   ,gs_was_tcr
1749#endif
1750                                   );
1751  } else {
1752    /* If we're not on the value stack, we pretty much have to be on
1753       the C stack.  Just run the handler. */
1754#ifdef DARWIN_GS_HACK
1755    if (gs_was_tcr) {
1756      set_gs_address(tcr);
1757    }
1758#endif
1759    interrupt_handler(signum, info, context);
1760  }
1761}
1762
1763#else /* altstack works */
1764 
1765void
1766altstack_interrupt_handler (int signum, siginfo_t *info, ExceptionInformation *context)
1767{
1768#ifdef DARWIN_GS_HACK
1769  Boolean gs_was_tcr = ensure_gs_pthread();
1770#endif
1771  TCR *tcr = get_interrupt_tcr(false);
1772  handle_signal_on_foreign_stack(tcr,interrupt_handler,signum,info,context,(LispObj)__builtin_return_address(0)
1773#ifdef DARWIN_GS_HACK
1774                                 ,gs_was_tcr
1775#endif
1776                                 );
1777}
1778
1779#endif
1780#endif
1781
1782#ifndef WINDOWS
1783void
1784install_signal_handler(int signo, void * handler)
1785{
1786  struct sigaction sa;
1787 
1788  sa.sa_sigaction = (void *)handler;
1789  sigfillset(&sa.sa_mask);
1790#ifdef FREEBSD
1791  /* Strange FreeBSD behavior wrt synchronous signals */
1792  sigdelset(&sa.sa_mask,SIGTRAP);  /* let GDB work */
1793#endif
1794  sa.sa_flags = 
1795    0 /* SA_RESTART */
1796#ifdef USE_SIGALTSTACK
1797    | SA_ONSTACK
1798#endif
1799    | SA_SIGINFO;
1800
1801  sigaction(signo, &sa, NULL);
1802}
1803#endif
1804
1805#ifdef WINDOWS
1806BOOL
1807CALLBACK ControlEventHandler(DWORD event)
1808{
1809  switch(event) {
1810  case CTRL_C_EVENT:
1811    lisp_global(INTFLAG) = (1 << fixnumshift);
1812    return TRUE;
1813    break;
1814  default:
1815    return FALSE;
1816  }
1817}
1818
1819int
1820map_windows_exception_code_to_posix_signal(DWORD code)
1821{
1822  switch (code) {
1823  case EXCEPTION_ACCESS_VIOLATION:
1824    return SIGSEGV;
1825  case EXCEPTION_FLT_DENORMAL_OPERAND:
1826  case EXCEPTION_FLT_DIVIDE_BY_ZERO:
1827  case EXCEPTION_FLT_INEXACT_RESULT:
1828  case EXCEPTION_FLT_INVALID_OPERATION:
1829  case EXCEPTION_FLT_OVERFLOW:
1830  case EXCEPTION_FLT_STACK_CHECK:
1831  case EXCEPTION_FLT_UNDERFLOW:
1832  case EXCEPTION_INT_DIVIDE_BY_ZERO:
1833  case EXCEPTION_INT_OVERFLOW:
1834    return SIGFPE;
1835  case EXCEPTION_PRIV_INSTRUCTION:
1836  case EXCEPTION_ILLEGAL_INSTRUCTION:
1837    return SIGILL;
1838  case EXCEPTION_IN_PAGE_ERROR:
1839    return SIGBUS;
1840  default:
1841    return -1;
1842  }
1843}
1844
1845
1846LONG
1847windows_exception_handler(EXCEPTION_POINTERS *exception_pointers, TCR *tcr)
1848{
1849  DWORD code = exception_pointers->ExceptionRecord->ExceptionCode;
1850  int old_valence, signal_number;
1851  ExceptionInformation *context = exception_pointers->ContextRecord;
1852  siginfo_t *info = exception_pointers->ExceptionRecord;
1853  xframe_list xframes;
1854
1855  old_valence = prepare_to_wait_for_exception_lock(tcr, context);
1856  wait_for_exception_lock_in_handler(tcr, context, &xframes);
1857
1858  signal_number = map_windows_exception_code_to_posix_signal(code);
1859 
1860  if (!handle_exception(signal_number, info, context, tcr, old_valence)) {
1861    char msg[512];
1862    Boolean foreign = (old_valence != TCR_STATE_LISP);
1863
1864    snprintf(msg, sizeof(msg), "Unhandled exception %d (windows code 0x%x) at 0x%Ix, context->regs at 0x%Ix", signal_number, code, xpPC(context), (natural)xpGPRvector(context));
1865   
1866    if (lisp_Debugger(context, info, signal_number,  foreign, msg)) {
1867      SET_TCR_FLAG(tcr,TCR_FLAG_BIT_PROPAGATE_EXCEPTION);
1868    }
1869  }
1870  unlock_exception_lock_in_handler(tcr);
1871  return restore_windows_context(context, tcr, old_valence);
1872}
1873
1874void
1875setup_exception_handler_call(CONTEXT *context,
1876                             LispObj new_sp,
1877                             void *handler,
1878                             EXCEPTION_POINTERS *new_ep,
1879                             TCR *tcr)
1880{
1881  extern void windows_halt(void);
1882  LispObj *p = (LispObj *)new_sp;
1883#ifdef WIN_64
1884  p-=4;                         /* win64 abi argsave nonsense */
1885  *(--p) = (LispObj)windows_halt;
1886  context->Rsp = (DWORD64)p;
1887  context->Rip = (DWORD64)handler;
1888  context->Rcx = (DWORD64)new_ep;
1889  context->Rdx = (DWORD64)tcr;
1890#else
1891  p-=4;                          /* args on stack, stack aligned */
1892  p[0] = (LispObj)new_ep;
1893  p[1] = (LispObj)tcr;
1894  *(--p) = (LispObj)windows_halt;
1895  context->Esp = (DWORD)p;
1896  context->Eip = (DWORD)handler;
1897#ifdef WIN32_ES_HACK
1898  context->SegEs = context->SegDs;
1899#endif
1900#endif
1901  context->EFlags &= ~0x400;  /* clear direction flag */
1902}
1903
1904void
1905prepare_to_handle_windows_exception_on_foreign_stack(TCR *tcr,
1906                                                     CONTEXT *context,
1907                                                     void *handler,
1908                                                     EXCEPTION_POINTERS *original_ep)
1909{
1910  LispObj foreign_rsp = 
1911    (LispObj) (tcr->foreign_sp - 128) & ~15;
1912  CONTEXT *new_context;
1913  siginfo_t *new_info;
1914  EXCEPTION_POINTERS *new_ep;
1915
1916  new_context = ((CONTEXT *)(foreign_rsp&~15))-1;
1917  *new_context = *context;
1918  foreign_rsp = (LispObj)new_context;
1919  new_info = ((siginfo_t *)(foreign_rsp&~15))-1;
1920  *new_info = *original_ep->ExceptionRecord;
1921  foreign_rsp = (LispObj)new_info;
1922  new_ep = ((EXCEPTION_POINTERS *)(foreign_rsp&~15))-1;
1923  foreign_rsp = (LispObj)new_ep & ~15;
1924  new_ep->ContextRecord = new_context;
1925  new_ep->ExceptionRecord = new_info;
1926  setup_exception_handler_call(context,foreign_rsp,handler,new_ep, tcr);
1927}
1928
1929LONG CALLBACK
1930windows_arbstack_exception_handler(EXCEPTION_POINTERS *exception_pointers)
1931{
1932  extern void ensure_safe_for_string_operations(void);
1933  DWORD code = exception_pointers->ExceptionRecord->ExceptionCode;
1934
1935
1936 
1937  if ((code & 0x80000000L) == 0) {
1938    return EXCEPTION_CONTINUE_SEARCH;
1939  } else {
1940    TCR *tcr = get_interrupt_tcr(false);
1941    area *cs = tcr->cs_area;
1942    BytePtr current_sp = (BytePtr) current_stack_pointer();
1943    CONTEXT *context = exception_pointers->ContextRecord;
1944   
1945    ensure_safe_for_string_operations();
1946
1947    if ((current_sp >= cs->low) &&
1948        (current_sp < cs->high)) {
1949      debug_show_registers(context, exception_pointers->ExceptionRecord, 0);
1950      FBug(context, "Exception on foreign stack\n");
1951      return EXCEPTION_CONTINUE_EXECUTION;
1952    }
1953
1954    prepare_to_handle_windows_exception_on_foreign_stack(tcr,
1955                                                         context,
1956                                                         windows_exception_handler,
1957                                                         exception_pointers);
1958    return EXCEPTION_CONTINUE_EXECUTION;
1959  }
1960}
1961
1962
1963void
1964install_pmcl_exception_handlers()
1965{
1966  AddVectoredExceptionHandler(1,windows_arbstack_exception_handler);
1967}
1968#else
1969void
1970install_pmcl_exception_handlers()
1971{
1972#ifndef DARWIN 
1973  void *handler = (void *)
1974#ifdef USE_SIGALTSTACK
1975    altstack_signal_handler
1976#else
1977    arbstack_signal_handler;
1978#endif
1979  ;
1980  install_signal_handler(SIGILL, handler);
1981 
1982  install_signal_handler(SIGBUS, handler);
1983  install_signal_handler(SIGSEGV,handler);
1984  install_signal_handler(SIGFPE, handler);
1985#endif
1986 
1987  install_signal_handler(SIGNAL_FOR_PROCESS_INTERRUPT,
1988#ifdef USE_SIGALTSTACK
1989                         altstack_interrupt_handler
1990#else
1991                         arbstack_interrupt_handler
1992#endif
1993);
1994  signal(SIGPIPE, SIG_IGN);
1995}
1996#endif
1997
1998#ifndef WINDOWS
1999#ifndef USE_SIGALTSTACK
2000void
2001arbstack_suspend_resume_handler(int signum, siginfo_t *info, ExceptionInformation  *context)
2002{
2003#ifdef DARWIN_GS_HACK
2004  Boolean gs_was_tcr = ensure_gs_pthread();
2005#endif
2006  TCR *tcr = get_interrupt_tcr(false);
2007  if (tcr != NULL) {
2008    area *vs = tcr->vs_area;
2009    BytePtr current_sp = (BytePtr) current_stack_pointer();
2010   
2011    if ((current_sp >= vs->low) &&
2012        (current_sp < vs->high)) {
2013      return
2014        handle_signal_on_foreign_stack(tcr,
2015                                       suspend_resume_handler,
2016                                       signum,
2017                                       info,
2018                                       context,
2019                                       (LispObj)__builtin_return_address(0)
2020#ifdef DARWIN_GS_HACK
2021                                       ,gs_was_tcr
2022#endif
2023                                       );
2024    } else {
2025      /* If we're not on the value stack, we pretty much have to be on
2026         the C stack.  Just run the handler. */
2027#ifdef DARWIN_GS_HACK
2028      if (gs_was_tcr) {
2029        set_gs_address(tcr);
2030      }
2031#endif
2032    }
2033  }
2034  suspend_resume_handler(signum, info, context);
2035}
2036
2037
2038#else /* altstack works */
2039void
2040altstack_suspend_resume_handler(int signum, siginfo_t *info, ExceptionInformation  *context)
2041{
2042#ifdef DARWIN_GS_HACK
2043  Boolean gs_was_tcr = ensure_gs_pthread();
2044#endif
2045  TCR* tcr = get_tcr(true);
2046  handle_signal_on_foreign_stack(tcr,
2047                                 suspend_resume_handler,
2048                                 signum,
2049                                 info,
2050                                 context,
2051                                 (LispObj)__builtin_return_address(0)
2052#ifdef DARWIN_GS_HACK
2053                                 ,gs_was_tcr
2054#endif
2055                                 );
2056}
2057#endif
2058#endif
2059
2060
2061/* This should only be called when the tcr_area_lock is held */
2062void
2063empty_tcr_stacks(TCR *tcr)
2064{
2065  if (tcr) {
2066    area *a;
2067
2068    tcr->valence = TCR_STATE_FOREIGN;
2069    a = tcr->vs_area;
2070    if (a) {
2071      a->active = a->high;
2072    }
2073    a = tcr->ts_area;
2074    if (a) {
2075      a->active = a->high;
2076    }
2077    a = tcr->cs_area;
2078    if (a) {
2079      a->active = a->high;
2080    }
2081  }
2082}
2083
2084#ifdef WINDOWS
2085void
2086thread_kill_handler(int signum, siginfo_t *info, ExceptionInformation *xp)
2087{
2088}
2089#else
2090void
2091thread_kill_handler(int signum, siginfo_t *info, ExceptionInformation *xp)
2092{
2093#ifdef DARWIN_GS_HACK
2094  Boolean gs_was_tcr = ensure_gs_pthread();
2095#endif
2096  TCR *tcr = get_tcr(false);
2097  sigset_t mask;
2098
2099  sigemptyset(&mask);
2100
2101  empty_tcr_stacks(tcr);
2102
2103  pthread_sigmask(SIG_SETMASK,&mask,NULL);
2104  pthread_exit(NULL);
2105}
2106#endif
2107
2108#ifndef WINDOWS
2109#ifndef USE_SIGALTSTACK
2110void
2111arbstack_thread_kill_handler(int signum, siginfo_t *info, ExceptionInformation *context)
2112{
2113#ifdef DARWIN_GS_HACK
2114  Boolean gs_was_tcr = ensure_gs_pthread();
2115#endif
2116  TCR *tcr = get_interrupt_tcr(false);
2117  area *vs = tcr->vs_area;
2118  BytePtr current_sp = (BytePtr) current_stack_pointer();
2119
2120  if ((current_sp >= vs->low) &&
2121      (current_sp < vs->high)) {
2122    handle_signal_on_foreign_stack(tcr,
2123                                   thread_kill_handler,
2124                                   signum,
2125                                   info,
2126                                   context,
2127                                   (LispObj)__builtin_return_address(0)
2128#ifdef DARWIN_GS_HACK
2129                                   ,gs_was_tcr
2130#endif
2131                                   );
2132  } else {
2133    /* If we're not on the value stack, we pretty much have to be on
2134       the C stack.  Just run the handler. */
2135#ifdef DARWIN_GS_HACK
2136    if (gs_was_tcr) {
2137      set_gs_address(tcr);
2138    }
2139#endif
2140    thread_kill_handler(signum, info, context);
2141  }
2142}
2143
2144
2145#else
2146void
2147altstack_thread_kill_handler(int signum, siginfo_t *info, ExceptionInformation *context)
2148{
2149#ifdef DARWIN_GS_HACK
2150  Boolean gs_was_tcr = ensure_gs_pthread();
2151#endif
2152  TCR* tcr = get_tcr(true);
2153  handle_signal_on_foreign_stack(tcr,
2154                                 thread_kill_handler,
2155                                 signum,
2156                                 info,
2157                                 context,
2158                                 (LispObj)__builtin_return_address(0)
2159#ifdef DARWIN_GS_HACK
2160                                 ,gs_was_tcr
2161#endif
2162                                 );
2163}
2164#endif
2165#endif
2166
2167#ifdef USE_SIGALTSTACK
2168#define SUSPEND_RESUME_HANDLER altstack_suspend_resume_handler
2169#define THREAD_KILL_HANDLER altstack_thread_kill_handler
2170#else
2171#define SUSPEND_RESUME_HANDLER arbstack_suspend_resume_handler
2172#define THREAD_KILL_HANDLER arbstack_thread_kill_handler
2173#endif
2174
2175#ifdef WINDOWS
2176void
2177thread_signal_setup()
2178{
2179}
2180#else
2181void
2182thread_signal_setup()
2183{
2184  thread_suspend_signal = SIG_SUSPEND_THREAD;
2185  thread_kill_signal = SIG_KILL_THREAD;
2186
2187  install_signal_handler(thread_suspend_signal, (void *)SUSPEND_RESUME_HANDLER);
2188  install_signal_handler(thread_kill_signal, (void *)THREAD_KILL_HANDLER);
2189}
2190#endif
2191
2192void
2193enable_fp_exceptions()
2194{
2195}
2196
2197void
2198exception_init()
2199{
2200  install_pmcl_exception_handlers();
2201}
2202
2203void
2204adjust_exception_pc(ExceptionInformation *xp, int delta)
2205{
2206  xpPC(xp) += delta;
2207}
2208
2209/*
2210  Lower (move toward 0) the "end" of the soft protected area associated
2211  with a by a page, if we can.
2212*/
2213
2214void
2215
2216adjust_soft_protection_limit(area *a)
2217{
2218  char *proposed_new_soft_limit = a->softlimit - 4096;
2219  protected_area_ptr p = a->softprot;
2220 
2221  if (proposed_new_soft_limit >= (p->start+16384)) {
2222    p->end = proposed_new_soft_limit;
2223    p->protsize = p->end-p->start;
2224    a->softlimit = proposed_new_soft_limit;
2225  }
2226  protect_area(p);
2227}
2228
2229void
2230restore_soft_stack_limit(unsigned restore_tsp)
2231{
2232  TCR *tcr = get_tcr(false);
2233  area *a;
2234 
2235  if (restore_tsp) {
2236    a = tcr->ts_area;
2237  } else {
2238    a = tcr->vs_area;
2239  }
2240  adjust_soft_protection_limit(a);
2241}
2242
2243
2244#ifdef USE_SIGALTSTACK
2245void
2246setup_sigaltstack(area *a)
2247{
2248  stack_t stack;
2249  stack.ss_sp = a->low;
2250  a->low += SIGSTKSZ*8;
2251  stack.ss_size = SIGSTKSZ*8;
2252  stack.ss_flags = 0;
2253  mmap(stack.ss_sp,stack.ss_size, PROT_READ|PROT_WRITE|PROT_EXEC,MAP_FIXED|MAP_ANON|MAP_PRIVATE,-1,0);
2254  if (sigaltstack(&stack, NULL) != 0) {
2255    perror("sigaltstack");
2256    exit(-1);
2257  }
2258}
2259#endif
2260
2261extern opcode egc_write_barrier_start, egc_write_barrier_end,
2262  egc_set_hash_key_conditional, egc_set_hash_key_conditional_success_test,
2263  egc_set_hash_key_conditional_retry,
2264  egc_store_node_conditional_success_end,
2265  egc_store_node_conditional_success_test,egc_store_node_conditional,
2266  egc_set_hash_key, egc_gvset, egc_rplacd;
2267
2268/* We use (extremely) rigidly defined instruction sequences for consing,
2269   mostly so that 'pc_luser_xp()' knows what to do if a thread is interrupted
2270   while consing.
2271
2272   Note that we can usually identify which of these instructions is about
2273   to be executed by a stopped thread without comparing all of the bytes
2274   to those at the stopped program counter, but we generally need to
2275   know the sizes of each of these instructions.
2276*/
2277
2278#ifdef X8664
2279opcode load_allocptr_reg_from_tcr_save_allocptr_instruction[] =
2280#ifdef WINDOWS
2281  {0x49,0x8b,0x9b,0xd8,0x00,0x00,0x00}
2282#else
2283  {0x65,0x48,0x8b,0x1c,0x25,0xd8,0x00,0x00,0x00}
2284#endif
2285;
2286opcode compare_allocptr_reg_to_tcr_save_allocbase_instruction[] =
2287#ifdef WINDOWS
2288  {0x49,0x3b,0x9b,0xe0,0x00,0x00,0x00}
2289#else
2290  {0x65,0x48,0x3b,0x1c,0x25,0xe0,0x00,0x00,0x00}
2291#endif
2292
2293;
2294opcode branch_around_alloc_trap_instruction[] =
2295  {0x77,0x02};
2296opcode alloc_trap_instruction[] =
2297  {0xcd,0xc5};
2298opcode clear_tcr_save_allocptr_tag_instruction[] =
2299#ifdef WINDOWS
2300  {0x41,0x80,0xa3,0xd8,0x00,0x00,0x00,0xf0}
2301#else
2302  {0x65,0x80,0x24,0x25,0xd8,0x00,0x00,0x00,0xf0}
2303#endif
2304;
2305opcode set_allocptr_header_instruction[] =
2306  {0x48,0x89,0x43,0xf3};
2307
2308
2309alloc_instruction_id
2310recognize_alloc_instruction(pc program_counter)
2311{
2312  switch(program_counter[0]) {
2313  case 0xcd: return ID_alloc_trap_instruction;
2314  /* 0x7f is jg, which we used to use here instead of ja */
2315  case 0x7f:
2316  case 0x77: return ID_branch_around_alloc_trap_instruction;
2317  case 0x48: return ID_set_allocptr_header_instruction;
2318#ifdef WINDOWS
2319  case 0x41: return ID_clear_tcr_save_allocptr_tag_instruction;
2320  case 0x49:
2321    switch(program_counter[1]) {
2322    case 0x8b: return ID_load_allocptr_reg_from_tcr_save_allocptr_instruction;
2323    case 0x3b: return ID_compare_allocptr_reg_to_tcr_save_allocbase_instruction;
2324    }
2325#else
2326  case 0x65: 
2327    switch(program_counter[1]) {
2328    case 0x80: return ID_clear_tcr_save_allocptr_tag_instruction;
2329    case 0x48:
2330      switch(program_counter[2]) {
2331      case 0x3b: return ID_compare_allocptr_reg_to_tcr_save_allocbase_instruction;
2332      case 0x8b: return ID_load_allocptr_reg_from_tcr_save_allocptr_instruction;
2333      }
2334    }
2335#endif
2336  default: break;
2337  }
2338  return ID_unrecognized_alloc_instruction;
2339}
2340#endif
2341#ifdef X8632
2342/* The lisp assembler might use both a modrm byte and a sib byte to
2343   encode a memory operand that contains a displacement but no
2344   base or index.  Using the sib byte is necessary for 64-bit code,
2345   since the sib-less form is used to indicate %rip-relative addressing
2346   on x8664.  On x8632, it's not necessary, slightly suboptimal, and
2347   doesn't match what we expect; until that's fixed, we may need to
2348   account for this extra byte when adjusting the PC */
2349#define LISP_ASSEMBLER_EXTRA_SIB_BYTE
2350#ifdef WIN32_ES_HACK
2351/* Win32 keeps the TCR in %es */
2352#define TCR_SEG_PREFIX 0x26     /* %es: */
2353#else
2354/* Other platfroms use %fs */
2355#define TCR_SEG_PREFIX 0x64     /* %fs: */
2356#endif
2357opcode load_allocptr_reg_from_tcr_save_allocptr_instruction[] =
2358  {TCR_SEG_PREFIX,0x8b,0x0d,0x84,0x00,0x00,0x00};  /* may have extra SIB byte */
2359opcode compare_allocptr_reg_to_tcr_save_allocbase_instruction[] =
2360  {TCR_SEG_PREFIX,0x3b,0x0d,0x88,0x00,0x00,0x00};  /* may have extra SIB byte */
2361opcode branch_around_alloc_trap_instruction[] =
2362  {0x77,0x02};                  /* no SIB byte issue */
2363opcode alloc_trap_instruction[] =
2364  {0xcd,0xc5};                  /* no SIB byte issue */
2365opcode clear_tcr_save_allocptr_tag_instruction[] =
2366  {TCR_SEG_PREFIX,0x80,0x25,0x84,0x00,0x00,0x00,0xf8}; /* maybe SIB byte */
2367opcode set_allocptr_header_instruction[] =
2368  {0x0f,0x7e,0x41,0xfa};        /* no SIB byte issue */
2369
2370alloc_instruction_id
2371recognize_alloc_instruction(pc program_counter)
2372{
2373  switch(program_counter[0]) {
2374  case 0xcd: return ID_alloc_trap_instruction;
2375  /* 0x7f is jg, which we used to use here instead of ja */
2376  case 0x7f:
2377  case 0x77: return ID_branch_around_alloc_trap_instruction;
2378  case 0x0f: return ID_set_allocptr_header_instruction;
2379  case TCR_SEG_PREFIX: 
2380    switch(program_counter[1]) {
2381    case 0x80: return ID_clear_tcr_save_allocptr_tag_instruction;
2382    case 0x3b: return ID_compare_allocptr_reg_to_tcr_save_allocbase_instruction;
2383    case 0x8b: return ID_load_allocptr_reg_from_tcr_save_allocptr_instruction;
2384    }
2385  }
2386  return ID_unrecognized_alloc_instruction;
2387}
2388#endif     
2389
2390void
2391pc_luser_xp(ExceptionInformation *xp, TCR *tcr, signed_natural *interrupt_displacement)
2392{
2393  pc program_counter = (pc)xpPC(xp);
2394  int allocptr_tag = fulltag_of((LispObj)(tcr->save_allocptr));
2395
2396  if (allocptr_tag != 0) {
2397    alloc_instruction_id state = recognize_alloc_instruction(program_counter);
2398    signed_natural
2399      disp = (allocptr_tag == fulltag_cons) ?
2400      sizeof(cons) - fulltag_cons :
2401#ifdef X8664
2402      xpGPR(xp,Iimm1)
2403#else
2404      xpGPR(xp,Iimm0)
2405#endif
2406      ;
2407    LispObj new_vector;
2408
2409    if ((state == ID_unrecognized_alloc_instruction) ||
2410        ((state == ID_set_allocptr_header_instruction) &&
2411         (allocptr_tag != fulltag_misc))) {
2412      Bug(xp, "Can't determine state of thread 0x" LISP ", interrupted during memory allocation", tcr);
2413    }
2414    switch(state) {
2415    case ID_set_allocptr_header_instruction:
2416      /* We were consing a vector and we won.  Set the header of the
2417         new vector (in the allocptr register) to the header in %rax
2418         (%mm0 on ia32) and skip over this instruction, then fall into
2419         the next case. */
2420      new_vector = xpGPR(xp,Iallocptr);
2421      deref(new_vector,0) = 
2422#ifdef X8664
2423        xpGPR(xp,Iimm0)
2424#else
2425        xpMMXreg(xp,Imm0)
2426#endif
2427        ;
2428     
2429      xpPC(xp) += sizeof(set_allocptr_header_instruction);
2430
2431      /* Fall thru */
2432    case ID_clear_tcr_save_allocptr_tag_instruction:
2433      tcr->save_allocptr = (void *)(((LispObj)tcr->save_allocptr) & ~fulltagmask);
2434#ifdef LISP_ASSEMBLER_EXTRA_SIB_BYTE
2435      if (((pc)(xpPC(xp)))[2] == 0x24) {
2436        xpPC(xp) += 1;
2437      }
2438#endif
2439      xpPC(xp) += sizeof(clear_tcr_save_allocptr_tag_instruction);
2440
2441      break;
2442    case ID_alloc_trap_instruction:
2443      /* If we're looking at another thread, we're pretty much committed to
2444         taking the trap.  We don't want the allocptr register to be pointing
2445         into the heap, so make it point to (- VOID_ALLOCPTR disp), where 'disp'
2446         was determined above.
2447      */
2448      if (interrupt_displacement == NULL) {
2449        xpGPR(xp,Iallocptr) = VOID_ALLOCPTR - disp;
2450        tcr->save_allocptr = (void *)(VOID_ALLOCPTR - disp);
2451      } else {
2452        /* Back out, and tell the caller how to resume the allocation attempt */
2453        *interrupt_displacement = disp;
2454        xpGPR(xp,Iallocptr) = VOID_ALLOCPTR;
2455        tcr->save_allocptr += disp;
2456#ifdef LISP_ASSEMBLER_EXTRA_SIB_BYTE
2457        /* This assumes that TCR_SEG_PREFIX can't appear
2458           anywhere but at the beginning of one of these
2459           magic allocation-sequence instructions. */
2460        xpPC(xp) -= (sizeof(branch_around_alloc_trap_instruction)+
2461                     sizeof(compare_allocptr_reg_to_tcr_save_allocbase_instruction));
2462        if (*((pc)(xpPC(xp))) == TCR_SEG_PREFIX) {
2463          xpPC(xp) -= sizeof(load_allocptr_reg_from_tcr_save_allocptr_instruction);
2464        } else {
2465          xpPC(xp) -= (sizeof(load_allocptr_reg_from_tcr_save_allocptr_instruction) + 2);
2466        }
2467       
2468#else
2469        xpPC(xp) -= (sizeof(branch_around_alloc_trap_instruction)+
2470                     sizeof(compare_allocptr_reg_to_tcr_save_allocbase_instruction) +
2471                     sizeof(load_allocptr_reg_from_tcr_save_allocptr_instruction));
2472#endif
2473      }
2474      break;
2475    case ID_branch_around_alloc_trap_instruction:
2476      /* If we'd take the branch - which is a "ja" - around the alloc trap,
2477         we might as well finish the allocation.  Otherwise, back out of the
2478         attempt. */
2479      {
2480        int flags = (int)eflags_register(xp);
2481       
2482        if ((!(flags & (1 << X86_ZERO_FLAG_BIT))) &&
2483            (!(flags & (1 << X86_CARRY_FLAG_BIT)))) {
2484          /* The branch (ja) would have been taken.  Emulate taking it. */
2485          xpPC(xp) += (sizeof(branch_around_alloc_trap_instruction)+
2486                       sizeof(alloc_trap_instruction));
2487          if (allocptr_tag == fulltag_misc) {
2488            /* Slap the header on the new uvector */
2489            new_vector = xpGPR(xp,Iallocptr);
2490            deref(new_vector,0) = xpGPR(xp,Iimm0);
2491            xpPC(xp) += sizeof(set_allocptr_header_instruction);
2492          }
2493          tcr->save_allocptr = (void *)(((LispObj)tcr->save_allocptr) & ~fulltagmask);
2494#ifdef LISP_ASSEMBLER_EXTRA_SIB_BYTE
2495          if (((pc)xpPC(xp))[2] == 0x24) {
2496            xpPC(xp) += 1;
2497          }
2498#endif
2499          xpPC(xp) += sizeof(clear_tcr_save_allocptr_tag_instruction);
2500        } else {
2501          /* Back up */
2502          xpPC(xp) -= (sizeof(compare_allocptr_reg_to_tcr_save_allocbase_instruction) +
2503                       sizeof(load_allocptr_reg_from_tcr_save_allocptr_instruction));
2504#ifdef LISP_ASSEMBLER_EXTRA_SIB_BYTE
2505          if (*((pc)(xpPC(xp))) != TCR_SEG_PREFIX) {
2506            /* skipped two instructions with extra SIB byte */
2507            xpPC(xp) -= 2;
2508          }
2509#endif
2510          xpGPR(xp,Iallocptr) = VOID_ALLOCPTR;
2511          if (interrupt_displacement) {
2512            *interrupt_displacement = disp;
2513            tcr->save_allocptr += disp;
2514          } else {
2515            tcr->save_allocptr = (void *)(VOID_ALLOCPTR-disp);
2516          }
2517        }
2518      }
2519      break;
2520    case ID_compare_allocptr_reg_to_tcr_save_allocbase_instruction:
2521      xpGPR(xp,Iallocptr) = VOID_ALLOCPTR;
2522      xpPC(xp) -= sizeof(load_allocptr_reg_from_tcr_save_allocptr_instruction);
2523#ifdef LISP_ASSEMBLER_EXTRA_SIB_BYTE
2524      if (*((pc)xpPC(xp)) != TCR_SEG_PREFIX) {
2525        xpPC(xp) -= 1;
2526      }
2527#endif
2528      /* Fall through */
2529    case ID_load_allocptr_reg_from_tcr_save_allocptr_instruction:
2530      if (interrupt_displacement) {
2531        tcr->save_allocptr += disp;
2532        *interrupt_displacement = disp;
2533      } else {
2534        tcr->save_allocptr = (void *)(VOID_ALLOCPTR-disp);
2535      }
2536      break;
2537    default: 
2538      break;
2539    }
2540    return;
2541  }
2542  if ((program_counter >= &egc_write_barrier_start) &&
2543      (program_counter < &egc_write_barrier_end)) {
2544    LispObj *ea = 0, val, root = 0;
2545    bitvector refbits = (bitvector)(lisp_global(REFBITS));
2546    Boolean need_store = true, need_check_memo = true, need_memoize_root = false;
2547
2548    if (program_counter >= &egc_set_hash_key_conditional) {
2549      if (program_counter <= &egc_set_hash_key_conditional_retry) {
2550        return;
2551      }
2552      if ((program_counter < &egc_set_hash_key_conditional_success_test) ||
2553          ((program_counter == &egc_set_hash_key_conditional_success_test) &&
2554           !(eflags_register(xp) & (1 << X86_ZERO_FLAG_BIT)))) {
2555        /* Back up the PC, try again */
2556        xpPC(xp) = (LispObj) &egc_set_hash_key_conditional_retry;
2557        return;
2558      }
2559      /* The conditional store succeeded.  Set the refbit, return to ra0 */
2560      val = xpGPR(xp,Iarg_z);
2561#ifdef X8664
2562      root = xpGPR(xp,Iarg_x);
2563      ea = (LispObj*)(root + (unbox_fixnum((signed_natural) xpGPR(xp,Itemp0))));
2564#else
2565      root = xpGPR(xp,Itemp1);
2566      ea = (LispObj *)(root + misc_data_offset + xpGPR(xp,Itemp0));
2567#endif
2568      need_memoize_root = true;
2569      need_store = false;
2570      xpGPR(xp,Iarg_z) = t_value;
2571    } else if (program_counter >= &egc_store_node_conditional) {
2572      if ((program_counter < &egc_store_node_conditional_success_test) ||
2573          ((program_counter == &egc_store_node_conditional_success_test) &&
2574           !(eflags_register(xp) & (1 << X86_ZERO_FLAG_BIT)))) {
2575        /* Back up the PC, try again */
2576        xpPC(xp) = (LispObj) &egc_store_node_conditional;
2577        return;
2578      }
2579      if (program_counter >= &egc_store_node_conditional_success_end) {
2580        return;
2581      }
2582
2583      /* The conditional store succeeded.  Set the refbit, return to ra0 */
2584      val = xpGPR(xp,Iarg_z);
2585#ifdef X8664
2586      ea = (LispObj*)(xpGPR(xp,Iarg_x) + (unbox_fixnum((signed_natural)
2587                                                       xpGPR(xp,Itemp0))));
2588#else
2589      ea = (LispObj *)(misc_data_offset + xpGPR(xp,Itemp1) + xpGPR(xp,Itemp0));
2590#endif
2591      xpGPR(xp,Iarg_z) = t_value;
2592      need_store = false;
2593    } else if (program_counter >= &egc_set_hash_key) {
2594#ifdef X8664
2595      root = xpGPR(xp,Iarg_x);
2596#else
2597      root = xpGPR(xp,Itemp0);
2598#endif
2599      ea = (LispObj *) (root+xpGPR(xp,Iarg_y)+misc_data_offset);
2600      val = xpGPR(xp,Iarg_z);
2601      need_memoize_root = true;
2602    } else if (program_counter >= &egc_gvset) {
2603#ifdef X8664
2604      ea = (LispObj *) (xpGPR(xp,Iarg_x)+xpGPR(xp,Iarg_y)+misc_data_offset);
2605#else
2606      ea = (LispObj *) (xpGPR(xp,Itemp0)+xpGPR(xp,Iarg_y)+misc_data_offset);
2607#endif
2608      val = xpGPR(xp,Iarg_z);
2609    } else if (program_counter >= &egc_rplacd) {
2610      ea = (LispObj *) untag(xpGPR(xp,Iarg_y));
2611      val = xpGPR(xp,Iarg_z);
2612    } else {                      /* egc_rplaca */
2613      ea =  ((LispObj *) untag(xpGPR(xp,Iarg_y)))+1;
2614      val = xpGPR(xp,Iarg_z);
2615    }
2616    if (need_store) {
2617      *ea = val;
2618    }
2619    if (need_check_memo) {
2620      natural  bitnumber = area_dnode(ea, lisp_global(HEAP_START));
2621      if ((bitnumber < lisp_global(OLDSPACE_DNODE_COUNT)) &&
2622          ((LispObj)ea < val)) {
2623        atomic_set_bit(refbits, bitnumber);
2624        if (need_memoize_root) {
2625          bitnumber = area_dnode(root, lisp_global(HEAP_START));
2626          atomic_set_bit(refbits, bitnumber);
2627        }
2628      }
2629    }
2630    {
2631      /* These subprimitives are called via CALL/RET; need
2632         to pop the return address off the stack and set
2633         the PC there. */
2634      LispObj *sp = (LispObj *)xpGPR(xp,Isp), ra = *sp++;
2635      xpPC(xp) = ra;
2636      xpGPR(xp,Isp)=(LispObj)sp;
2637    }
2638    return;
2639  }
2640}
2641
2642
2643void
2644normalize_tcr(ExceptionInformation *xp, TCR *tcr, Boolean is_other_tcr)
2645{
2646  void *cur_allocptr = (void *)(tcr->save_allocptr);
2647  LispObj lisprsp;
2648  area *a;
2649
2650  if (xp) {
2651    if (is_other_tcr) {
2652      pc_luser_xp(xp, tcr, NULL);
2653    }
2654    a = tcr->vs_area;
2655    lisprsp = xpGPR(xp, Isp);
2656    if (((BytePtr)lisprsp >= a->low) &&
2657        ((BytePtr)lisprsp < a->high)) {
2658      a->active = (BytePtr)lisprsp;
2659    } else {
2660      a->active = (BytePtr) tcr->save_vsp;
2661    }
2662    a = tcr->ts_area;
2663    a->active = (BytePtr) tcr->save_tsp;
2664  } else {
2665    /* In ff-call; get area active pointers from tcr */
2666    tcr->vs_area->active = (BytePtr) tcr->save_vsp;
2667    tcr->ts_area->active = (BytePtr) tcr->save_tsp;
2668  }
2669  if (cur_allocptr) {
2670    update_bytes_allocated(tcr, cur_allocptr);
2671  }
2672  tcr->save_allocbase = (void *)VOID_ALLOCPTR;
2673  if (fulltag_of((LispObj)(tcr->save_allocptr)) == 0) {
2674    tcr->save_allocptr = (void *)VOID_ALLOCPTR;
2675  }
2676}
2677
2678
2679/* Suspend and "normalize" other tcrs, then call a gc-like function
2680   in that context.  Resume the other tcrs, then return what the
2681   function returned */
2682
2683TCR *gc_tcr = NULL;
2684
2685
2686signed_natural
2687gc_like_from_xp(ExceptionInformation *xp, 
2688                signed_natural(*fun)(TCR *, signed_natural), 
2689                signed_natural param)
2690{
2691  TCR *tcr = get_tcr(false), *other_tcr;
2692  int result;
2693  signed_natural inhibit;
2694
2695  suspend_other_threads(true);
2696  inhibit = (signed_natural)(lisp_global(GC_INHIBIT_COUNT));
2697  if (inhibit != 0) {
2698    if (inhibit > 0) {
2699      lisp_global(GC_INHIBIT_COUNT) = (LispObj)(-inhibit);
2700    }
2701    resume_other_threads(true);
2702    gc_deferred++;
2703    return 0;
2704  }
2705  gc_deferred = 0;
2706
2707  gc_tcr = tcr;
2708
2709  /* This is generally necessary if the current thread invoked the GC
2710     via an alloc trap, and harmless if the GC was invoked via a GC
2711     trap.  (It's necessary in the first case because the "allocptr"
2712     register - %rbx - may be pointing into the middle of something
2713     below tcr->save_allocbase, and we wouldn't want the GC to see
2714     that bogus pointer.) */
2715  xpGPR(xp, Iallocptr) = VOID_ALLOCPTR; 
2716
2717  normalize_tcr(xp, tcr, false);
2718
2719
2720  for (other_tcr = tcr->next; other_tcr != tcr; other_tcr = other_tcr->next) {
2721    if (other_tcr->pending_exception_context) {
2722      other_tcr->gc_context = other_tcr->pending_exception_context;
2723    } else if (other_tcr->valence == TCR_STATE_LISP) {
2724      other_tcr->gc_context = other_tcr->suspend_context;
2725    } else {
2726      /* no pending exception, didn't suspend in lisp state:
2727         must have executed a synchronous ff-call.
2728      */
2729      other_tcr->gc_context = NULL;
2730    }
2731    normalize_tcr(other_tcr->gc_context, other_tcr, true);
2732  }
2733   
2734
2735
2736  result = fun(tcr, param);
2737
2738  other_tcr = tcr;
2739  do {
2740    other_tcr->gc_context = NULL;
2741    other_tcr = other_tcr->next;
2742  } while (other_tcr != tcr);
2743
2744  gc_tcr = NULL;
2745
2746  resume_other_threads(true);
2747
2748  return result;
2749
2750}
2751
2752signed_natural
2753purify_from_xp(ExceptionInformation *xp, signed_natural param)
2754{
2755  return gc_like_from_xp(xp, purify, param);
2756}
2757
2758signed_natural
2759impurify_from_xp(ExceptionInformation *xp, signed_natural param)
2760{
2761  return gc_like_from_xp(xp, impurify, param);
2762}
2763
2764/* Returns #bytes freed by invoking GC */
2765
2766signed_natural
2767gc_from_tcr(TCR *tcr, signed_natural param)
2768{
2769  area *a;
2770  BytePtr oldfree, newfree;
2771  BytePtr oldend, newend;
2772
2773#if 0
2774  fprintf(dbgout, "Start GC  in 0x" LISP "\n", tcr);
2775#endif
2776  a = active_dynamic_area;
2777  oldend = a->high;
2778  oldfree = a->active;
2779  gc(tcr, param);
2780  newfree = a->active;
2781  newend = a->high;
2782#if 0
2783  fprintf(dbgout, "End GC  in 0x" LISP "\n", tcr);
2784#endif
2785  return ((oldfree-newfree)+(newend-oldend));
2786}
2787
2788signed_natural
2789gc_from_xp(ExceptionInformation *xp, signed_natural param)
2790{
2791  signed_natural status = gc_like_from_xp(xp, gc_from_tcr, param);
2792
2793  freeGCptrs();
2794  return status;
2795}
2796
2797#ifdef DARWIN
2798
2799#define TCR_FROM_EXCEPTION_PORT(p) ((TCR *)((natural)p))
2800#define TCR_TO_EXCEPTION_PORT(tcr) ((mach_port_t)((natural)(tcr)))
2801
2802extern void pseudo_sigreturn(void);
2803
2804
2805
2806#define LISP_EXCEPTIONS_HANDLED_MASK \
2807 (EXC_MASK_SOFTWARE | EXC_MASK_BAD_ACCESS | EXC_MASK_BAD_INSTRUCTION | EXC_MASK_ARITHMETIC)
2808
2809/* (logcount LISP_EXCEPTIONS_HANDLED_MASK) */
2810#define NUM_LISP_EXCEPTIONS_HANDLED 4
2811
2812typedef struct {
2813  int foreign_exception_port_count;
2814  exception_mask_t         masks[NUM_LISP_EXCEPTIONS_HANDLED];
2815  mach_port_t              ports[NUM_LISP_EXCEPTIONS_HANDLED];
2816  exception_behavior_t behaviors[NUM_LISP_EXCEPTIONS_HANDLED];
2817  thread_state_flavor_t  flavors[NUM_LISP_EXCEPTIONS_HANDLED];
2818} MACH_foreign_exception_state;
2819
2820
2821
2822
2823/*
2824  Mach's exception mechanism works a little better than its signal
2825  mechanism (and, not incidentally, it gets along with GDB a lot
2826  better.
2827
2828  Initially, we install an exception handler to handle each native
2829  thread's exceptions.  This process involves creating a distinguished
2830  thread which listens for kernel exception messages on a set of
2831  0 or more thread exception ports.  As threads are created, they're
2832  added to that port set; a thread's exception port is destroyed
2833  (and therefore removed from the port set) when the thread exits.
2834
2835  A few exceptions can be handled directly in the handler thread;
2836  others require that we resume the user thread (and that the
2837  exception thread resumes listening for exceptions.)  The user
2838  thread might eventually want to return to the original context
2839  (possibly modified somewhat.)
2840
2841  As it turns out, the simplest way to force the faulting user
2842  thread to handle its own exceptions is to do pretty much what
2843  signal() does: the exception handlng thread sets up a sigcontext
2844  on the user thread's stack and forces the user thread to resume
2845  execution as if a signal handler had been called with that
2846  context as an argument.  We can use a distinguished UUO at a
2847  distinguished address to do something like sigreturn(); that'll
2848  have the effect of resuming the user thread's execution in
2849  the (pseudo-) signal context.
2850
2851  Since:
2852    a) we have miles of code in C and in Lisp that knows how to
2853    deal with Linux sigcontexts
2854    b) Linux sigcontexts contain a little more useful information
2855    (the DAR, DSISR, etc.) than their Darwin counterparts
2856    c) we have to create a sigcontext ourselves when calling out
2857    to the user thread: we aren't really generating a signal, just
2858    leveraging existing signal-handling code.
2859
2860  we create a Linux sigcontext struct.
2861
2862  Simple ?  Hopefully from the outside it is ...
2863
2864  We want the process of passing a thread's own context to it to
2865  appear to be atomic: in particular, we don't want the GC to suspend
2866  a thread that's had an exception but has not yet had its user-level
2867  exception handler called, and we don't want the thread's exception
2868  context to be modified by a GC while the Mach handler thread is
2869  copying it around.  On Linux (and on Jaguar), we avoid this issue
2870  because (a) the kernel sets up the user-level signal handler and
2871  (b) the signal handler blocks signals (including the signal used
2872  by the GC to suspend threads) until tcr->xframe is set up.
2873
2874  The GC and the Mach server thread therefore contend for the lock
2875  "mach_exception_lock".  The Mach server thread holds the lock
2876  when copying exception information between the kernel and the
2877  user thread; the GC holds this lock during most of its execution
2878  (delaying exception processing until it can be done without
2879  GC interference.)
2880
2881*/
2882
2883#ifdef PPC64
2884#define C_REDZONE_LEN           320
2885#define C_STK_ALIGN             32
2886#else
2887#define C_REDZONE_LEN           224
2888#define C_STK_ALIGN             16
2889#endif
2890#define C_PARAMSAVE_LEN         64
2891#define C_LINKAGE_LEN           48
2892
2893#define TRUNC_DOWN(a,b,c)  (((((natural)a)-(b))/(c)) * (c))
2894
2895void
2896fatal_mach_error(char *format, ...);
2897
2898#define MACH_CHECK_ERROR(context,x) if (x != KERN_SUCCESS) {fatal_mach_error("Mach error while %s : %d", context, x);}
2899
2900
2901void
2902restore_mach_thread_state(mach_port_t thread, ExceptionInformation *pseudosigcontext)
2903{
2904  kern_return_t kret;
2905#if WORD_SIZE == 64
2906  MCONTEXT_T mc = UC_MCONTEXT(pseudosigcontext);
2907#else
2908  mcontext_t mc = UC_MCONTEXT(pseudosigcontext);
2909#endif
2910
2911  /* Set the thread's FP state from the pseudosigcontext */
2912#if WORD_SIZE == 64
2913  kret = thread_set_state(thread,
2914                          x86_FLOAT_STATE64,
2915                          (thread_state_t)&(mc->__fs),
2916                          x86_FLOAT_STATE64_COUNT);
2917#else
2918  kret = thread_set_state(thread,
2919                          x86_FLOAT_STATE32,
2920                          (thread_state_t)&(mc->__fs),
2921                          x86_FLOAT_STATE32_COUNT);
2922#endif
2923  MACH_CHECK_ERROR("setting thread FP state", kret);
2924
2925  /* The thread'll be as good as new ... */
2926#if WORD_SIZE == 64
2927  kret = thread_set_state(thread,
2928                          x86_THREAD_STATE64,
2929                          (thread_state_t)&(mc->__ss),
2930                          x86_THREAD_STATE64_COUNT);
2931#else
2932  kret = thread_set_state(thread, 
2933                          x86_THREAD_STATE32,
2934                          (thread_state_t)&(mc->__ss),
2935                          x86_THREAD_STATE32_COUNT);
2936#endif
2937  MACH_CHECK_ERROR("setting thread state", kret);
2938} 
2939
2940/* This code runs in the exception handling thread, in response
2941   to an attempt to execute the UU0 at "pseudo_sigreturn" (e.g.,
2942   in response to a call to pseudo_sigreturn() from the specified
2943   user thread.
2944   Find that context (the user thread's R3 points to it), then
2945   use that context to set the user thread's state.  When this
2946   function's caller returns, the Mach kernel will resume the
2947   user thread.
2948*/
2949
2950kern_return_t
2951do_pseudo_sigreturn(mach_port_t thread, TCR *tcr)
2952{
2953  ExceptionInformation *xp;
2954
2955#ifdef DEBUG_MACH_EXCEPTIONS
2956  fprintf(dbgout, "doing pseudo_sigreturn for 0x%x\n",tcr);
2957#endif
2958  xp = tcr->pending_exception_context;
2959  if (xp) {
2960    tcr->pending_exception_context = NULL;
2961    tcr->valence = TCR_STATE_LISP;
2962    restore_mach_thread_state(thread, xp);
2963    raise_pending_interrupt(tcr);
2964  } else {
2965    Bug(NULL, "no xp here!\n");
2966  }
2967#ifdef DEBUG_MACH_EXCEPTIONS
2968  fprintf(dbgout, "did pseudo_sigreturn for 0x%x\n",tcr);
2969#endif
2970  return KERN_SUCCESS;
2971} 
2972
2973ExceptionInformation *
2974create_thread_context_frame(mach_port_t thread, 
2975                            natural *new_stack_top,
2976                            siginfo_t **info_ptr,
2977                            TCR *tcr,
2978#ifdef X8664
2979                            x86_thread_state64_t *ts
2980#else
2981                            x86_thread_state32_t *ts
2982#endif
2983                            )
2984{
2985  mach_msg_type_number_t thread_state_count;
2986  ExceptionInformation *pseudosigcontext;
2987#ifdef X8664
2988  MCONTEXT_T mc;
2989#else
2990  mcontext_t mc;
2991#endif
2992  natural stackp;
2993
2994#ifdef X8664 
2995  stackp = (LispObj) find_foreign_rsp(ts->__rsp,tcr->cs_area,tcr);
2996  stackp = TRUNC_DOWN(stackp, C_REDZONE_LEN, C_STK_ALIGN);
2997#else
2998  stackp = (LispObj) find_foreign_rsp(ts->__esp, tcr->cs_area, tcr);
2999#endif
3000  stackp = TRUNC_DOWN(stackp, sizeof(siginfo_t), C_STK_ALIGN);
3001  if (info_ptr) {
3002    *info_ptr = (siginfo_t *)stackp;
3003  }
3004  stackp = TRUNC_DOWN(stackp,sizeof(*pseudosigcontext), C_STK_ALIGN);
3005  pseudosigcontext = (ExceptionInformation *) ptr_from_lispobj(stackp);
3006
3007  stackp = TRUNC_DOWN(stackp, sizeof(*mc), C_STK_ALIGN);
3008  mc = (MCONTEXT_T) ptr_from_lispobj(stackp);
3009 
3010  memmove(&(mc->__ss),ts,sizeof(*ts));
3011
3012#ifdef X8664
3013  thread_state_count = x86_FLOAT_STATE64_COUNT;
3014  thread_get_state(thread,
3015                   x86_FLOAT_STATE64,
3016                   (thread_state_t)&(mc->__fs),
3017                   &thread_state_count);
3018
3019  thread_state_count = x86_EXCEPTION_STATE64_COUNT;
3020  thread_get_state(thread,
3021                   x86_EXCEPTION_STATE64,
3022                   (thread_state_t)&(mc->__es),
3023                   &thread_state_count);
3024#else
3025  thread_state_count = x86_FLOAT_STATE32_COUNT;
3026  thread_get_state(thread,
3027                   x86_FLOAT_STATE32,
3028                   (thread_state_t)&(mc->__fs),
3029                   &thread_state_count);
3030
3031  thread_state_count = x86_EXCEPTION_STATE32_COUNT;
3032  thread_get_state(thread,
3033                   x86_EXCEPTION_STATE32,
3034                   (thread_state_t)&(mc->__es),
3035                   &thread_state_count);
3036#endif
3037
3038
3039  UC_MCONTEXT(pseudosigcontext) = mc;
3040  if (new_stack_top) {
3041    *new_stack_top = stackp;
3042  }
3043  return pseudosigcontext;
3044}
3045
3046/*
3047  This code sets up the user thread so that it executes a "pseudo-signal
3048  handler" function when it resumes.  Create a fake ucontext struct
3049  on the thread's stack and pass it as an argument to the pseudo-signal
3050  handler.
3051
3052  Things are set up so that the handler "returns to" pseudo_sigreturn(),
3053  which will restore the thread's context.
3054
3055  If the handler invokes code that throws (or otherwise never sigreturn()'s
3056  to the context), that's fine.
3057
3058  Actually, check that: throw (and variants) may need to be careful and
3059  pop the tcr's xframe list until it's younger than any frame being
3060  entered.
3061*/
3062
3063int
3064setup_signal_frame(mach_port_t thread,
3065                   void *handler_address,
3066                   int signum,
3067                   int code,
3068                   TCR *tcr,
3069#ifdef X8664
3070                   x86_thread_state64_t *ts
3071#else
3072                   x86_thread_state32_t *ts
3073#endif
3074                   )
3075{
3076#ifdef X8664
3077  x86_thread_state64_t new_ts;
3078#else
3079  x86_thread_state32_t new_ts;
3080#endif
3081  ExceptionInformation *pseudosigcontext;
3082  int  old_valence = tcr->valence;
3083  natural stackp, *stackpp;
3084  siginfo_t *info;
3085
3086#ifdef DEBUG_MACH_EXCEPTIONS
3087  fprintf(dbgout,"Setting up exception handling for 0x%x\n", tcr);
3088#endif
3089  pseudosigcontext = create_thread_context_frame(thread, &stackp, &info, tcr,  ts);
3090  bzero(info, sizeof(*info));
3091  info->si_code = code;
3092  info->si_addr = (void *)(UC_MCONTEXT(pseudosigcontext)->__es.__faultvaddr);
3093  info->si_signo = signum;
3094  pseudosigcontext->uc_onstack = 0;
3095  pseudosigcontext->uc_sigmask = (sigset_t) 0;
3096  pseudosigcontext->uc_stack.ss_sp = 0;
3097  pseudosigcontext->uc_stack.ss_size = 0;
3098  pseudosigcontext->uc_stack.ss_flags = 0;
3099  pseudosigcontext->uc_link = NULL;
3100  pseudosigcontext->uc_mcsize = sizeof(*UC_MCONTEXT(pseudosigcontext));
3101  tcr->pending_exception_context = pseudosigcontext;
3102  tcr->valence = TCR_STATE_EXCEPTION_WAIT;
3103 
3104
3105  /*
3106     It seems like we've created a  sigcontext on the thread's
3107     stack.  Set things up so that we call the handler (with appropriate
3108     args) when the thread's resumed.
3109  */
3110
3111#ifdef X8664
3112  new_ts.__rip = (natural) handler_address;
3113  stackpp = (natural *)stackp;
3114  *--stackpp = (natural)pseudo_sigreturn;
3115  stackp = (natural)stackpp;
3116  new_ts.__rdi = signum;
3117  new_ts.__rsi = (natural)info;
3118  new_ts.__rdx = (natural)pseudosigcontext;
3119  new_ts.__rcx = (natural)tcr;
3120  new_ts.__r8 = (natural)old_valence;
3121  new_ts.__rsp = stackp;
3122  new_ts.__rflags = ts->__rflags;
3123#else
3124#define USER_CS 0x17
3125#define USER_DS 0x1f
3126  bzero(&new_ts, sizeof(new_ts));
3127  new_ts.__cs = ts->__cs;
3128  new_ts.__ss = ts->__ss;
3129  new_ts.__ds = ts->__ds;
3130  new_ts.__es = ts->__es;
3131  new_ts.__fs = ts->__fs;
3132  new_ts.__gs = ts->__gs;
3133
3134  new_ts.__eip = (natural)handler_address;
3135  stackpp = (natural *)stackp;
3136  *--stackpp = 0;               /* alignment */
3137  *--stackpp = 0;
3138  *--stackpp = 0;
3139  *--stackpp = (natural)old_valence;
3140  *--stackpp = (natural)tcr;
3141  *--stackpp = (natural)pseudosigcontext;
3142  *--stackpp = (natural)info;
3143  *--stackpp = (natural)signum;
3144  *--stackpp = (natural)pseudo_sigreturn;
3145  stackp = (natural)stackpp;
3146  new_ts.__esp = stackp;
3147  new_ts.__eflags = ts->__eflags;
3148#endif
3149
3150#ifdef X8664
3151  thread_set_state(thread,
3152                   x86_THREAD_STATE64,
3153                   (thread_state_t)&new_ts,
3154                   x86_THREAD_STATE64_COUNT);
3155#else
3156  thread_set_state(thread, 
3157                   x86_THREAD_STATE32,
3158                   (thread_state_t)&new_ts,
3159                   x86_THREAD_STATE32_COUNT);
3160#endif
3161#ifdef DEBUG_MACH_EXCEPTIONS
3162  fprintf(dbgout,"Set up exception context for 0x%x at 0x%x\n", tcr, tcr->pending_exception_context);
3163#endif
3164  return 0;
3165}
3166
3167
3168
3169
3170
3171
3172/*
3173  This function runs in the exception handling thread.  It's
3174  called (by this precise name) from the library function "exc_server()"
3175  when the thread's exception ports are set up.  (exc_server() is called
3176  via mach_msg_server(), which is a function that waits for and dispatches
3177  on exception messages from the Mach kernel.)
3178
3179  This checks to see if the exception was caused by a pseudo_sigreturn()
3180  UUO; if so, it arranges for the thread to have its state restored
3181  from the specified context.
3182
3183  Otherwise, it tries to map the exception to a signal number and
3184  arranges that the thread run a "pseudo signal handler" to handle
3185  the exception.
3186
3187  Some exceptions could and should be handled here directly.
3188*/
3189
3190/* We need the thread's state earlier on x86_64 than we did on PPC;
3191   the PC won't fit in code_vector[1].  We shouldn't try to get it
3192   lazily (via catch_exception_raise_state()); until we own the
3193   exception lock, we shouldn't have it in userspace (since a GCing
3194   thread wouldn't know that we had our hands on it.)
3195*/
3196
3197#ifdef X8664
3198#define ts_pc(t) t.__rip
3199#else
3200#define ts_pc(t) t.__eip
3201#endif
3202
3203
3204#define DARWIN_EXCEPTION_HANDLER signal_handler
3205
3206
3207kern_return_t
3208catch_exception_raise(mach_port_t exception_port,
3209                      mach_port_t thread,
3210                      mach_port_t task, 
3211                      exception_type_t exception,
3212                      exception_data_t code_vector,
3213                      mach_msg_type_number_t code_count)
3214{
3215  int signum = 0, code = *code_vector;
3216  TCR *tcr = TCR_FROM_EXCEPTION_PORT(exception_port);
3217  kern_return_t kret, call_kret;
3218#ifdef X8664
3219  x86_thread_state64_t ts;
3220#else
3221  x86_thread_state32_t ts;
3222#endif
3223  mach_msg_type_number_t thread_state_count;
3224
3225
3226
3227
3228#ifdef DEBUG_MACH_EXCEPTIONS
3229  fprintf(dbgout, "obtaining Mach exception lock in exception thread\n");
3230#endif
3231
3232
3233  if (1) {
3234#ifdef X8664
3235    do {
3236      thread_state_count = x86_THREAD_STATE64_COUNT;
3237      call_kret = thread_get_state(thread,
3238                                   x86_THREAD_STATE64,
3239                                   (thread_state_t)&ts,
3240                                   &thread_state_count);
3241    } while (call_kret == KERN_ABORTED);
3242  MACH_CHECK_ERROR("getting thread state",call_kret);
3243#else
3244    thread_state_count = x86_THREAD_STATE32_COUNT;
3245    call_kret = thread_get_state(thread,
3246                                 x86_THREAD_STATE32,
3247                                 (thread_state_t)&ts,
3248                                 &thread_state_count);
3249    MACH_CHECK_ERROR("getting thread state",call_kret);
3250#endif
3251    if (tcr->flags & (1<<TCR_FLAG_BIT_PENDING_EXCEPTION)) {
3252      CLR_TCR_FLAG(tcr,TCR_FLAG_BIT_PENDING_EXCEPTION);
3253    } 
3254    if ((code == EXC_I386_GPFLT) &&
3255        ((natural)(ts_pc(ts)) == (natural)pseudo_sigreturn)) {
3256      kret = do_pseudo_sigreturn(thread, tcr);
3257#if 0
3258      fprintf(dbgout, "Exception return in 0x%x\n",tcr);
3259#endif
3260    } else if (tcr->flags & (1<<TCR_FLAG_BIT_PROPAGATE_EXCEPTION)) {
3261      CLR_TCR_FLAG(tcr,TCR_FLAG_BIT_PROPAGATE_EXCEPTION);
3262      kret = 17;
3263    } else {
3264      switch (exception) {
3265      case EXC_BAD_ACCESS:
3266        if (code == EXC_I386_GPFLT) {
3267          signum = SIGSEGV;
3268        } else {
3269          signum = SIGBUS;
3270        }
3271        break;
3272       
3273      case EXC_BAD_INSTRUCTION:
3274        if (code == EXC_I386_GPFLT) {
3275          signum = SIGSEGV;
3276        } else {
3277          signum = SIGILL;
3278        }
3279        break;
3280         
3281      case EXC_SOFTWARE:
3282        signum = SIGILL;
3283        break;
3284       
3285      case EXC_ARITHMETIC:
3286        signum = SIGFPE;
3287        break;
3288       
3289      default:
3290        break;
3291      }
3292      if (signum) {
3293        kret = setup_signal_frame(thread,
3294                                  (void *)DARWIN_EXCEPTION_HANDLER,
3295                                  signum,
3296                                  code,
3297                                  tcr, 
3298                                  &ts);
3299#if 0
3300        fprintf(dbgout, "Setup pseudosignal handling in 0x%x\n",tcr);
3301#endif
3302       
3303      } else {
3304        kret = 17;
3305      }
3306    }
3307  }
3308  return kret;
3309}
3310
3311
3312
3313
3314static mach_port_t mach_exception_thread = (mach_port_t)0;
3315
3316
3317/*
3318  The initial function for an exception-handling thread.
3319*/
3320
3321void *
3322exception_handler_proc(void *arg)
3323{
3324  extern boolean_t exc_server();
3325  mach_port_t p = TCR_TO_EXCEPTION_PORT(arg);
3326
3327  mach_exception_thread = pthread_mach_thread_np(pthread_self());
3328  mach_msg_server(exc_server, 256, p, 0);
3329  /* Should never return. */
3330  abort();
3331}
3332
3333
3334
3335void
3336mach_exception_thread_shutdown()
3337{
3338  kern_return_t kret;
3339
3340  fprintf(dbgout, "terminating Mach exception thread, 'cause exit can't\n");
3341  kret = thread_terminate(mach_exception_thread);
3342  if (kret != KERN_SUCCESS) {
3343    fprintf(dbgout, "Couldn't terminate exception thread, kret = %d\n",kret);
3344  }
3345}
3346
3347
3348mach_port_t
3349mach_exception_port_set()
3350{
3351  static mach_port_t __exception_port_set = MACH_PORT_NULL;
3352  kern_return_t kret; 
3353  if (__exception_port_set == MACH_PORT_NULL) {
3354
3355    kret = mach_port_allocate(mach_task_self(),
3356                              MACH_PORT_RIGHT_PORT_SET,
3357                              &__exception_port_set);
3358    MACH_CHECK_ERROR("allocating thread exception_ports",kret);
3359    create_system_thread(0,
3360                         NULL,
3361                         exception_handler_proc, 
3362                         (void *)((natural)__exception_port_set));
3363  }
3364  return __exception_port_set;
3365}
3366
3367/*
3368  Setup a new thread to handle those exceptions specified by
3369  the mask "which".  This involves creating a special Mach
3370  message port, telling the Mach kernel to send exception
3371  messages for the calling thread to that port, and setting
3372  up a handler thread which listens for and responds to
3373  those messages.
3374
3375*/
3376
3377/*
3378  Establish the lisp thread's TCR as its exception port, and determine
3379  whether any other ports have been established by foreign code for
3380  exceptions that lisp cares about.
3381
3382  If this happens at all, it should happen on return from foreign
3383  code and on entry to lisp code via a callback.
3384
3385  This is a lot of trouble (and overhead) to support Java, or other
3386  embeddable systems that clobber their caller's thread exception ports.
3387 
3388*/
3389kern_return_t
3390tcr_establish_exception_port(TCR *tcr, mach_port_t thread)
3391{
3392  kern_return_t kret;
3393  MACH_foreign_exception_state *fxs = (MACH_foreign_exception_state *)tcr->native_thread_info;
3394  int i;
3395  unsigned n = NUM_LISP_EXCEPTIONS_HANDLED;
3396  mach_port_t lisp_port = TCR_TO_EXCEPTION_PORT(tcr), foreign_port;
3397  exception_mask_t mask = 0;
3398
3399  kret = thread_swap_exception_ports(thread,
3400                                     LISP_EXCEPTIONS_HANDLED_MASK,
3401                                     lisp_port,
3402                                     EXCEPTION_DEFAULT,
3403                                     THREAD_STATE_NONE,
3404                                     fxs->masks,
3405                                     &n,
3406                                     fxs->ports,
3407                                     fxs->behaviors,
3408                                     fxs->flavors);
3409  if (kret == KERN_SUCCESS) {
3410    fxs->foreign_exception_port_count = n;
3411    for (i = 0; i < n; i ++) {
3412      foreign_port = fxs->ports[i];
3413
3414      if ((foreign_port != lisp_port) &&
3415          (foreign_port != MACH_PORT_NULL)) {
3416        mask |= fxs->masks[i];
3417      }
3418    }
3419    tcr->foreign_exception_status = (int) mask;
3420  }
3421  return kret;
3422}
3423
3424kern_return_t
3425tcr_establish_lisp_exception_port(TCR *tcr)
3426{
3427  return tcr_establish_exception_port(tcr, (mach_port_t)((natural)tcr->native_thread_id));
3428}
3429
3430/*
3431  Do this when calling out to or returning from foreign code, if
3432  any conflicting foreign exception ports were established when we
3433  last entered lisp code.
3434*/
3435kern_return_t
3436restore_foreign_exception_ports(TCR *tcr)
3437{
3438  exception_mask_t m = (exception_mask_t) tcr->foreign_exception_status;
3439 
3440  if (m) {
3441    MACH_foreign_exception_state *fxs  = 
3442      (MACH_foreign_exception_state *) tcr->native_thread_info;
3443    int i, n = fxs->foreign_exception_port_count;
3444    exception_mask_t tm;
3445
3446    for (i = 0; i < n; i++) {
3447      if ((tm = fxs->masks[i]) & m) {
3448        thread_set_exception_ports((mach_port_t)((natural)tcr->native_thread_id),
3449                                   tm,
3450                                   fxs->ports[i],
3451                                   fxs->behaviors[i],
3452                                   fxs->flavors[i]);
3453      }
3454    }
3455  }
3456}
3457                                   
3458
3459/*
3460  This assumes that a Mach port (to be used as the thread's exception port) whose
3461  "name" matches the TCR's 32-bit address has already been allocated.
3462*/
3463
3464kern_return_t
3465setup_mach_exception_handling(TCR *tcr)
3466{
3467  mach_port_t
3468    thread_exception_port = TCR_TO_EXCEPTION_PORT(tcr),
3469    task_self = mach_task_self();
3470  kern_return_t kret;
3471
3472  kret = mach_port_insert_right(task_self,
3473                                thread_exception_port,
3474                                thread_exception_port,
3475                                MACH_MSG_TYPE_MAKE_SEND);
3476  MACH_CHECK_ERROR("adding send right to exception_port",kret);
3477
3478  kret = tcr_establish_exception_port(tcr, (mach_port_t)((natural) tcr->native_thread_id));
3479  if (kret == KERN_SUCCESS) {
3480    mach_port_t exception_port_set = mach_exception_port_set();
3481
3482    kret = mach_port_move_member(task_self,
3483                                 thread_exception_port,
3484                                 exception_port_set);
3485  }
3486  return kret;
3487}
3488
3489void
3490darwin_exception_init(TCR *tcr)
3491{
3492  void tcr_monitor_exception_handling(TCR*, Boolean);
3493  kern_return_t kret;
3494  MACH_foreign_exception_state *fxs = 
3495    calloc(1, sizeof(MACH_foreign_exception_state));
3496 
3497  tcr->native_thread_info = (void *) fxs;
3498
3499  if ((kret = setup_mach_exception_handling(tcr))
3500      != KERN_SUCCESS) {
3501    fprintf(dbgout, "Couldn't setup exception handler - error = %d\n", kret);
3502    terminate_lisp();
3503  }
3504  lisp_global(LISP_EXIT_HOOK) = (LispObj) restore_foreign_exception_ports;
3505  lisp_global(LISP_RETURN_HOOK) = (LispObj) tcr_establish_lisp_exception_port;
3506}
3507
3508/*
3509  The tcr is the "name" of the corresponding thread's exception port.
3510  Destroying the port should remove it from all port sets of which it's
3511  a member (notably, the exception port set.)
3512*/
3513void
3514darwin_exception_cleanup(TCR *tcr)
3515{
3516  void *fxs = tcr->native_thread_info;
3517  extern Boolean use_mach_exception_handling;
3518
3519  if (fxs) {
3520    tcr->native_thread_info = NULL;
3521    free(fxs);
3522  }
3523  if (use_mach_exception_handling) {
3524    mach_port_deallocate(mach_task_self(),TCR_TO_EXCEPTION_PORT(tcr));
3525    mach_port_destroy(mach_task_self(),TCR_TO_EXCEPTION_PORT(tcr));
3526  }
3527}
3528
3529
3530Boolean
3531suspend_mach_thread(mach_port_t mach_thread)
3532{
3533  kern_return_t status;
3534  Boolean aborted = false;
3535 
3536  do {
3537    aborted = false;
3538    status = thread_suspend(mach_thread);
3539    if (status == KERN_SUCCESS) {
3540      status = thread_abort_safely(mach_thread);
3541      if (status == KERN_SUCCESS) {
3542        aborted = true;
3543      } else {
3544        fprintf(dbgout, "abort failed on thread = 0x%x\n",mach_thread);
3545        thread_resume(mach_thread);
3546      }
3547    } else {
3548      return false;
3549    }
3550  } while (! aborted);
3551  return true;
3552}
3553
3554/*
3555  Only do this if pthread_kill indicated that the pthread isn't
3556  listening to signals anymore, as can happen as soon as pthread_exit()
3557  is called on Darwin.  The thread could still call out to lisp as it
3558  is exiting, so we need another way to suspend it in this case.
3559*/
3560Boolean
3561mach_suspend_tcr(TCR *tcr)
3562{
3563  mach_port_t mach_thread = (mach_port_t)((natural)( tcr->native_thread_id));
3564  ExceptionInformation *pseudosigcontext;
3565  Boolean result = false;
3566 
3567  result = suspend_mach_thread(mach_thread);
3568  if (result) {
3569    mach_msg_type_number_t thread_state_count;
3570#ifdef X8664
3571    x86_thread_state64_t ts;
3572    thread_state_count = x86_THREAD_STATE64_COUNT;
3573    thread_get_state(mach_thread,
3574                     x86_THREAD_STATE64,
3575                     (thread_state_t)&ts,
3576                     &thread_state_count);
3577#else
3578    x86_thread_state32_t ts;
3579    thread_state_count = x86_THREAD_STATE_COUNT;
3580    thread_get_state(mach_thread,
3581                     x86_THREAD_STATE,
3582                     (thread_state_t)&ts,
3583                     &thread_state_count);
3584#endif
3585
3586    pseudosigcontext = create_thread_context_frame(mach_thread, NULL, NULL,tcr, &ts);
3587    pseudosigcontext->uc_onstack = 0;
3588    pseudosigcontext->uc_sigmask = (sigset_t) 0;
3589    tcr->suspend_context = pseudosigcontext;
3590  }
3591  return result;
3592}
3593
3594void
3595mach_resume_tcr(TCR *tcr)
3596{
3597  ExceptionInformation *xp;
3598  mach_port_t mach_thread = (mach_port_t)((natural)(tcr->native_thread_id));
3599 
3600  xp = tcr->suspend_context;
3601#ifdef DEBUG_MACH_EXCEPTIONS
3602  fprintf(dbgout, "resuming TCR 0x%x, pending_exception_context = 0x%x\n",
3603          tcr, tcr->pending_exception_context);
3604#endif
3605  tcr->suspend_context = NULL;
3606  restore_mach_thread_state(mach_thread, xp);
3607#ifdef DEBUG_MACH_EXCEPTIONS
3608  fprintf(dbgout, "restored state in TCR 0x%x, pending_exception_context = 0x%x\n",
3609          tcr, tcr->pending_exception_context);
3610#endif
3611  thread_resume(mach_thread);
3612}
3613
3614void
3615fatal_mach_error(char *format, ...)
3616{
3617  va_list args;
3618  char s[512];
3619 
3620
3621  va_start(args, format);
3622  vsnprintf(s, sizeof(s),format, args);
3623  va_end(args);
3624
3625  Fatal("Mach error", s);
3626}
3627
3628
3629
3630
3631#endif
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