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1.1 root 1: /*
2:
3: * Copyright 1991,1992,1993 Atari Corporation.
4:
5: * All rights reserved.
6:
7: */
8:
9:
10:
11: /*
12:
13: * page-table data structures
14:
15: *
16:
17: *
18:
19: * The root pointer points to a list of pointers to top-level pointer tables.
20:
21: *
22:
23: * Each entry in a pointer table points to another pointer table or to
24:
25: * a page table, or is a page descriptor.
26:
27: *
28:
29: * Since, initially, the logical address space is the physical address space,
30:
31: * we only need to worry about 26MB plus 32K for I/O space.
32:
33: *
34:
35: * Since we want some pages to be supervisor-accessible, but we don't want
36:
37: * a whole separate table for that, we use long-format descriptors.
38:
39: *
40:
41: * Initial memory map:
42:
43: *
44:
45: * 0 - membot: S (supervisor only)
46:
47: * membot - memtop: P (protected TPA)
48:
49: * memtop - phystop: G (screen)
50:
51: * phystop - $00E00000: bus error
52:
53: * $00E00000- $00E3FFFF: G (ROM)
54:
55: * $00E40000- $00FF7FFF: bus error
56:
57: * $00FF8000- $00FFFFFF: G (mostly S: I/O space, but that's done in hardware)
58:
59: * $01000000- ramtop: P
60:
61: * ramtop - $7FFFFFFF: G (A32/D32 VME, cacheable)
62:
63: * $80000000- $FEFFFFFF: G (A32/D32 VME, non cacheable)
64:
65: * $FFxxxxxx just like $00xxxxxx.
66:
67: *
68:
69: * Here's a final choice of layouts: IS=0, PS=13 (8K), TIA=4, TIB=4, TIC=4,
70:
71: * TID=7. This lets us map out entire unused megabytes at level C, and gives
72:
73: * us an 8K page size, which is the largest the '040 can deal with.
74:
75: *
76:
77: * This code implements 4+4+4+7, as follows:
78:
79: *
80:
81: * tbl_a
82:
83: * 0 -> tbl_b0
84:
85: * 1-7 -> Cacheable direct (VME) page descriptors
86:
87: * 8-E -> Non-cacheable direct (VME) page descriptors
88:
89: * F -> tbl_bf
90:
91: *
92:
93: * tbl_b0 table: 16 entries (assumes only 16MB of TT RAM)
94:
95: * 0 -> tbl_c00 (16MB of ST RAM address space)
96:
97: * 1 -> tbl_c01 (16MB of TT RAM address space)
98:
99: * 2-F -> cacheable direct (VME) page descriptors
100:
101: *
102:
103: * tbl_bF table: 16 entries (deals with $FF mapping to $00)
104:
105: * 0-E -> Non-cacheable direct (VME) page descriptors
106:
107: * F -> tbl_c00 (16MB of ST RAM address space, repeated here as $FF)
108:
109: *
110:
111: * tbl_c00 table: ST RAM address space (example assuming 4MB ST RAM)
112:
113: * 0-3 -> RAM page tables
114:
115: * 4-D -> invalid
116:
117: * E -> direct map, cache enable (ROM)
118:
119: * F -> direct map, cache inhibit (I/O)
120:
121: *
122:
123: * For each 16MB containing any TT RAM, there's a tbl_c. Within those,
124:
125: * for each MB that actually has TT RAM, there's another table, containing
126:
127: * 128 RAM page tables. Where there isn't RAM, there are "global"
128:
129: * pages, to let the hardware bus error or not as it sees fit.
130:
131: *
132:
133: * One RAM page table is allocated per megabyte of real RAM; each table has
134:
135: * 128 entries, which is 8K per page. For a TT with 4MB ST RAM and 4MB TT RAM
136:
137: * that's 8K in page tables. You can cut this down by not allocating page
138:
139: * tables for which the entire megabyte is not accessible (i.e. it's all
140:
141: * private memory and it's not YOUR private memory).
142:
143: *
144:
145: * You have one of these per process. When somebody loads into G or S memory
146:
147: * or leaves it, you have to go through the page tables of every process
148:
149: * updating S bits (for S) and DT (for G) bits.
150:
151: *
152:
153: * The top levels are small & easy so replicating them once per process
154:
155: * doesn't really hurt us.
156:
157: *
158:
159: */
160:
161:
162:
163: #include "mint.h"
164:
165:
166:
167: #if 0
168:
169: #define MP_DEBUG(x) DEBUG(x)
170:
171: #else
172:
173: #define MP_DEBUG(x)
174:
175: #endif
176:
177:
178:
179: void *memset P_((void *s, int ucharfill, unsigned long size));
180:
181: static void _dump_tree P_((long_desc tbl, int level));
182:
183:
184:
185: extern int debug_level; /* see debug.c */
186:
187:
188:
189: /*
190:
191: * You can turn this whole module off, and the stuff in context.s,
192:
193: * by setting no_mem_prot to 1.
194:
195: */
196:
197:
198:
199: int no_mem_prot;
200:
201: long page_table_size;
202:
203:
204:
205: /*
206:
207: * PMMU stuff
208:
209: */
210:
211: #if 1
212:
213: #define flush_pmmu(start, end) __asm("pflusha")
214:
215: #else
216:
217: /* in cpu.spp is a new "cpush" function that can selectively flush
218:
219: * the cache
220:
221: */
222:
223: #define flush_pmmu(start, len) cpush((void *)(start), (long)(len))
224:
225: #endif
226:
227:
228:
229: /*
230:
231: * This is one global TC register that is copied into every process'
232:
233: * context, even though it never changes. It's also used by the
234:
235: * functions that dump page tables.
236:
237: */
238:
239:
240:
241: tc_reg tc;
242:
243:
244:
245: /* mint_top_* get used in mem.c also */
246:
247: ulong mint_top_tt;
248:
249: ulong mint_top_st;
250:
251:
252:
253: int tt_mbytes; /* number of megabytds of TT RAM */
254:
255:
256:
257: /*
258:
259: * global_mode_table: one byte per page in the system. Initially all pages
260:
261: * are set to "global" but then the TPA pages are set to "invalid" in
262:
263: * init_mem. This has to be allocated and initialized in init_tables,
264:
265: * when you know how much memory there is. You need a byte per page,
266:
267: * from zero to the end of TT RAM, including the space between STRAM
268:
269: * and TTRAM. That is, you need 16MB/pagesize plus (tt_mbytes/pagesize)
270:
271: * bytes here.
272:
273: */
274:
275:
276:
277: unsigned char *global_mode_table;
278:
279:
280:
281: /*
282:
283: * prototype descriptors; field u1 must be all ones, other u? are zero.
284:
285: * This is just the first long of a full descriptor; the ".page_type" part
286:
287: * of the union. These are initialized by init_tables.
288:
289: *
290:
291: * The proto_page_type table yields the value to stuff into the page_type
292:
293: * field of a new process' page table. It is the "non-owner" mode for
294:
295: * a page with the corresponding value in global_mode_table.
296:
297: */
298:
299:
300:
301: page_type g_page;
302:
303: page_type g_ci_page;
304:
305: page_type s_page;
306:
307: page_type readable_page;
308:
309: page_type invalid_page;
310:
311: page_type page_ptr;
312:
313:
314:
315: page_type *proto_page_type[] =
316:
317: { &invalid_page, &g_page, &s_page, &readable_page, &invalid_page };
318:
319: /* private global super private/read invalid */
320:
321:
322:
323: /*
324:
325: * Init_tables: called sometime in initialization. We set up some
326:
327: * constants here, but that's all. The first new_proc call will set up the
328:
329: * page table for the root process and switch it in; from then on, we're
330:
331: * always under some process' control.
332:
333: *
334:
335: * The master page-mode table is initialized here, and some constants like
336:
337: * the size needed for future page tables.
338:
339: *
340:
341: * One important constant initialized here is page_table_size, which is
342:
343: * the amount of memory required per page table. new_proc allocates
344:
345: * this much memory for each process' page table. This number will be
346:
347: * 1K/megabyte plus page table overhead. There are TBL_PAGES_OFFS
348:
349: * tables at TBL_SIZE_BYTES each before the main tables begin; then
350:
351: * there is 1024 bytes per megabyte of memory being mapped.
352:
353: */
354:
355:
356:
357: void
358:
359: init_tables()
360:
361: {
362:
363: int n_megabytes;
364:
365: long global_mode_table_size;
366:
367:
368:
369: if (no_mem_prot) return;
370:
371:
372:
373: TRACE(("init_tables"));
374:
375:
376:
377: #define phys_top_tt (*(ulong *)0x5a4L)
378:
379: if (phys_top_tt == 0x01000000L) mint_top_tt = 0;
380:
381: else mint_top_tt = phys_top_tt;
382:
383:
384:
385: #define phys_top_st (*(ulong *)0x42eL)
386:
387: mint_top_st = phys_top_st;
388:
389:
390:
391: if (mint_top_tt)
392:
393: tt_mbytes = (int) ((mint_top_tt - 0x01000000L) / ONE_MEG);
394:
395: else
396:
397: tt_mbytes = 0;
398:
399:
400:
401: n_megabytes = (int) ((mint_top_st / ONE_MEG) + tt_mbytes);
402:
403:
404:
405: /*
406:
407: * page table size: room for A table, B0 table, BF table, STRAM C
408:
409: * table, one TTRAM C table per 16MB (or fraction) of TTRAM, and 1024
410:
411: * bytes per megabyte.
412:
413: */
414:
415:
416:
417: page_table_size = (4L * TBL_SIZE_BYTES) +
418:
419: (((tt_mbytes+15L)/16L) * TBL_SIZE_BYTES) +
420:
421: (n_megabytes*1024L);
422:
423:
424:
425: global_mode_table_size = ((SIXTEEN_MEG / QUANTUM) +
426:
427: (((ulong)tt_mbytes * ONE_MEG) / QUANTUM));
428:
429:
430:
431: global_mode_table = kmalloc(global_mode_table_size);
432:
433:
434:
435: assert(global_mode_table);
436:
437:
438:
439: TRACELOW(("mint_top_st is $%lx; mint_top_tt is $%lx, n_megabytes is %d",
440:
441: mint_top_st, mint_top_tt, n_megabytes));
442:
443: TRACELOW(("page_table_size is %ld, global_mode_table_size %ld",
444:
445: page_table_size,
446:
447: global_mode_table_size));
448:
449:
450:
451: g_page.limit = 0x7fff; /* set nonzero fields: disabled limit */
452:
453: g_page.unused1 = 0x3f; /* ones in this reserved field */
454:
455: g_page.unused2 = 0;
456:
457: g_page.s = 0;
458:
459: g_page.unused3 = 0;
460:
461: g_page.ci = 0;
462:
463: g_page.unused4 = 0;
464:
465: g_page.m = 1; /* set m and u to 1 so CPU won't do writes */
466:
467: g_page.u = 1;
468:
469: g_page.wp = 0; /* not write-protected */
470:
471: g_page.dt = 1; /* descriptor type 1: page descriptor */
472:
473:
474:
475: g_ci_page = g_page;
476:
477: g_ci_page.ci = 1;
478:
479:
480:
481: readable_page = g_page; /* a page which is globally readable */
482:
483: readable_page.wp = 1; /* but write protected */
484:
485:
486:
487: s_page = g_page; /* a page which is globally accessible */
488:
489: s_page.s = 1; /* if you're supervisor */
490:
491:
492:
493: invalid_page = g_page;
494:
495: invalid_page.dt = 0;
496:
497:
498:
499: page_ptr = g_page;
500:
501: page_ptr.m = 0; /* this must be zero in page pointers */
502:
503: page_ptr.dt = 3;
504:
505:
506:
507: tc.enable = 1;
508:
509: tc.zeros = 0;
510:
511: tc.sre = 0;
512:
513: tc.fcl = 0;
514:
515: tc.is = 0;
516:
517: tc.tia = 4;
518:
519: tc.tib = 4;
520:
521: tc.tic = 4;
522:
523: tc.tid = 7; /* 0+4+4+4+7+13 == 32 */
524:
525: tc.ps = 13; /* 8K page size */
526:
527:
528:
529: /* set the whole global_mode_table to "global" */
530:
531: memset(global_mode_table,PROT_G,global_mode_table_size);
532:
533: }
534:
535:
536:
537: /*
538:
539: * mark_region: mark a region of memory as having a particular type.
540:
541: * The arguments are the memory region in question and the new type.
542:
543: * If the new type is zero then the old type is preserved. The
544:
545: * type of each page is kept in a global place for this purpose,
546:
547: * among others.
548:
549: *
550:
551: * The types are:
552:
553: * 0 private
554:
555: * 1 global
556:
557: * 2 private, but super-accessible
558:
559: * 3 private, but world readable
560:
561: * 4 invalid
562:
563: *
564:
565:
566:
567: The idea is this:
568:
569:
570:
571: for (each process) {
572:
573: if (you're an owner or you're special) {
574:
575: set up owner modes
576:
577: }
578:
579: else {
580:
581: set up non-owner modes
582:
583: }
584:
585:
586:
587: mark_pages(pagetbl,start,len,modes);
588:
589: }
590:
591:
592:
593: */
594:
595:
596:
597: /*
598:
599: invalid---v
600:
601: private/gr---v |
602:
603: super-------v | |
604:
605: global-------v | | |
606:
607: private-------v | | | |
608:
609: | | | | |
610:
611: */
612:
613: ushort other_dt[] = { 0, 1, 1, 1, 0 };
614:
615: ushort other_s[] = { 0, 0, 1, 0, 0 };
616:
617: ushort other_wp[] = { 0, 0, 0, 1, 0 };
618:
619:
620:
621:
622:
623: /*
624:
625: * get_page_cookie: return a cookie representing the protection status
626:
627: * of some memory.
628:
629: *
630:
631: * Returns ((wp << 3) | (s << 2) | (dt) | 0x8000) when it wins.
632:
633: * Returns 1 if the pages are not all controlled, 0 if they're not all the same.
634:
635: */
636:
637:
638:
639: static short
640:
641: get_page_cookie(long_desc *base_tbl,ulong start,ulong len)
642:
643: {
644:
645: int b_index, c_index, d_index;
646:
647: long_desc *tbl;
648:
649: int dt, s, wp;
650:
651:
652:
653: if (start < mint_top_st) {
654:
655: /* start is in ST RAM; fail if not entirely in ST RAM */
656:
657: if (start+len > mint_top_st) {
658:
659: return 1;
660:
661: }
662:
663: }
664:
665: else if (start >= 0x01000000L && start < mint_top_tt) {
666:
667: /* start is in TT RAM; fail if not entirely in TT RAM */
668:
669: if (start+len > mint_top_tt) {
670:
671: return 1;
672:
673: }
674:
675: }
676:
677:
678:
679: b_index = (int)(start >> LOG2_16_MEG);
680:
681: c_index = (int)(start >> LOG2_ONE_MEG) & 0xf;
682:
683: d_index = (int)(start >> LOG2_EIGHT_K) & 0x7f;
684:
685:
686:
687: tbl = &(base_tbl[0].
688:
689: tbl_address[b_index].
690:
691: tbl_address[c_index].
692:
693: tbl_address[d_index]);
694:
695:
696:
697: dt = tbl->page_type.dt;
698:
699: wp = tbl->page_type.wp;
700:
701: s = tbl->page_type.s;
702:
703:
704:
705: /*
706:
707: * This can be optimized: while in a single megabyte, a quick loop on
708:
709: * successive long_desc's will work; similarly, while in a single 16MB,
710:
711: * an outer loop on the same C-level table works.
712:
713: */
714:
715:
716:
717: while (len) {
718:
719: /*
720:
721: * a_index is always zero. Only the first 256MB is mapped.
722:
723: * b_index is the 16MB number of the page.
724:
725: * c_index is the 1MB number of that page within the 16MB (0-15)
726:
727: * d_index is the 8K number within that 1MB (0-127).
728:
729: */
730:
731: b_index = (int)(start >> LOG2_16_MEG);
732:
733: c_index = (int)(start >> LOG2_ONE_MEG) & 0xf;
734:
735: d_index = (int)(start >> LOG2_EIGHT_K) & 0x7f;
736:
737:
738:
739: tbl = base_tbl; /* tbl := start of A table */
740:
741: tbl = tbl[0].tbl_address; /* B table */
742:
743: tbl = tbl[b_index].tbl_address; /* C table */
744:
745: tbl = tbl[c_index].tbl_address; /* D table */
746:
747: tbl = &tbl[d_index]; /* tbl := addr of page entry */
748:
749:
750:
751: if ((tbl->page_type.dt != dt) ||
752:
753: (tbl->page_type.s != s) ||
754:
755: (tbl->page_type.wp != wp)) {
756:
757: /* fail because it's not all the same protection */
758:
759: return 0;
760:
761: }
762:
763: len -= EIGHT_K;
764:
765: start += EIGHT_K;
766:
767: }
768:
769: /* we passed -- all the pages in question have the same prot. status */
770:
771: return (wp << 3) | (s << 2) | dt | 0x8000;
772:
773: }
774:
775:
776:
777: static void
778:
779: mark_pages(long_desc *base_tbl,ulong start,ulong len,
780:
781: ushort dt_val, ushort s_val, ushort wp_val, PROC *proc)
782:
783: {
784:
785: int b_index, c_index, d_index;
786:
787: long_desc *tbl;
788:
789: ulong oldstart, oldlen;
790:
791:
792:
793: if (no_mem_prot) return;
794:
795:
796:
797: oldstart = start;
798:
799: oldlen = len;
800:
801:
802:
803: #ifdef MEMPROT_SHORTCUT
804:
805: /*
806:
807: * Take a shortcut here: we're done if first page of the region is
808:
809: * already right. We duplicate the top of the "while" loop to do it,
810:
811: * but what the heck.
812:
813: */
814:
815: /* I don't think this shortcut is a good idea, since while we
816:
817: * are doing Mshrink or Srealloc we may very well have a region
818:
819: * with mixed page types -- ERS
820:
821: */
822:
823:
824:
825: b_index = (start >> LOG2_16_MEG);
826:
827: c_index = (start >> LOG2_ONE_MEG) & 0xf;
828:
829: d_index = (start >> LOG2_EIGHT_K) & 0x7f;
830:
831:
832:
833: tbl = &(base_tbl[0].
834:
835: tbl_address[b_index].
836:
837: tbl_address[c_index].
838:
839: tbl_address[d_index]);
840:
841:
842:
843: if (tbl->page_type.dt == dt_val &&
844:
845: tbl->page_type.s == s_val &&
846:
847: tbl->page_type.wp == wp_val) {
848:
849: /*
850:
851: TRACE(("mark_pages a:0 b:%d c:%d d:%d (same)",
852:
853: b_index,c_index,d_index));
854:
855: */
856:
857: return;
858:
859: }
860:
861:
862:
863: #endif /* MEMPROT_SHORTCUT */
864:
865: /*
866:
867: MP_DEBUG(("mark_pages a:0 b:%d c:%d d:%d (diff)",b_index,c_index,d_index));
868:
869: */
870:
871:
872:
873: /*
874:
875: * This can be optimized: while in a single megabyte, a quick loop on
876:
877: * successive long_desc's will work; similarly, while in a single 16MB,
878:
879: * an outer loop on the same C-level table works.
880:
881: */
882:
883:
884:
885: while (len) {
886:
887: /*
888:
889: * a_index is always zero. Only the first 256MB is mapped.
890:
891: * b_index is the 16MB number of the page.
892:
893: * c_index is the 1MB number of that page within the 16MB (0-15)
894:
895: * d_index is the 8K number within that 1MB (0-127).
896:
897: */
898:
899: b_index = (int)(start >> LOG2_16_MEG);
900:
901: c_index = (int)(start >> LOG2_ONE_MEG) & 0xf;
902:
903: d_index = (int)(start >> LOG2_EIGHT_K) & 0x7f;
904:
905:
906:
907: tbl = base_tbl; /* tbl := start of A table */
908:
909: tbl = tbl[0].tbl_address; /* B table */
910:
911: tbl = tbl[b_index].tbl_address; /* C table */
912:
913: tbl = tbl[c_index].tbl_address; /* D table */
914:
915: tbl = &tbl[d_index]; /* tbl := addr of page entry */
916:
917:
918:
919: tbl->page_type.dt = dt_val;
920:
921: tbl->page_type.s = s_val;
922:
923: tbl->page_type.wp = wp_val;
924:
925: len -= EIGHT_K;
926:
927: start += EIGHT_K;
928:
929: }
930:
931:
932:
933: #if 0
934:
935: /*
936:
937: * Flush the mmu address translation cache only if we changed curproc's
938:
939: * table.
940:
941: */
942:
943:
944:
945: if (proc == curproc) flush_pmmu(oldstart, oldlen);
946:
947: #else
948:
949: flush_pmmu(oldstart, oldlen);
950:
951: #endif
952:
953: }
954:
955:
956:
957: /* get_prot_mode(r): returns the type of protection region r
958:
959: * has
960:
961: */
962:
963:
964:
965: int
966:
967: get_prot_mode(r)
968:
969: MEMREGION *r;
970:
971: {
972:
973: ulong start = r->loc;
974:
975:
976:
977: if (no_mem_prot)
978:
979: return PROT_G;
980:
981: return global_mode_table[(start >> 13)];
982:
983: }
984:
985:
986:
987: void
988:
989: mark_region(region,mode)
990:
991: MEMREGION *region;
992:
993: short mode;
994:
995: {
996:
997: ulong start = region->loc;
998:
999: ulong len = region->len;
1000:
1001: ulong i;
1002:
1003: ushort dt_val, s_val, wp_val;
1004:
1005: PROC *proc;
1006:
1007: MEMREGION **mr;
1008:
1009: int change;
1010:
1011:
1012:
1013: if (no_mem_prot) return;
1014:
1015:
1016:
1017: MP_DEBUG(("mark_region %lx len %lx mode %d",start,len,mode));
1018:
1019:
1020:
1021: if (mode == PROT_NOCHANGE) {
1022:
1023: mode = global_mode_table[(start >> 13)];
1024:
1025: }
1026:
1027:
1028:
1029: if (global_mode_table[(start >> 13)] == mode) {
1030:
1031: change = 0;
1032:
1033: }
1034:
1035: else change = 1;
1036:
1037:
1038:
1039: /* mark the global page table */
1040:
1041:
1042:
1043: memset(&global_mode_table[start >> 13],mode,(len >> 13));
1044:
1045:
1046:
1047: for (proc = proclist; proc; proc = proc->gl_next) {
1048:
1049: assert(proc->page_table);
1050:
1051: if (mode == PROT_I || mode == PROT_G) {
1052:
1053: /* everybody gets the same flags */
1054:
1055: goto notowner;
1056:
1057: }
1058:
1059: if (proc->memflags & F_OS_SPECIAL) {
1060:
1061: /* you're special; you get owner flags */
1062:
1063: MP_DEBUG(("mark_region: pid %d is an OS special!",proc->pid));
1064:
1065: goto owner;
1066:
1067: }
1068:
1069: if (0 != (mr = proc->mem)) {
1070:
1071: for (i = 0; i < proc->num_reg; i++, mr++) {
1072:
1073: if (*mr == region) {
1074:
1075: MP_DEBUG(("mark_region: pid %d is an owner",proc->pid));
1076:
1077: owner:
1078:
1079: dt_val = 1;
1080:
1081: s_val = 0;
1082:
1083: wp_val = 0;
1084:
1085: goto gotvals;
1086:
1087: }
1088:
1089: }
1090:
1091: }
1092:
1093:
1094:
1095: notowner:
1096:
1097:
1098:
1099: /* if you get here you're not an owner, or mode is G or I */
1100:
1101: MP_DEBUG(("mark_region: pid %d gets non-owner modes",proc->pid));
1102:
1103:
1104:
1105: dt_val = other_dt[mode];
1106:
1107: s_val = other_s[mode];
1108:
1109: wp_val = other_wp[mode];
1110:
1111:
1112:
1113: gotvals:
1114:
1115: mark_pages(proc->page_table,start,len,dt_val,s_val,wp_val,proc);
1116:
1117: }
1118:
1119: }
1120:
1121:
1122:
1123: /*
1124:
1125: * prot_temp: temporarily alter curproc's access to memory.
1126:
1127: * Pass in a -1 to give curproc global access; returns a cookie. Call
1128:
1129: * again with that cookie to return the memory to the old mode.
1130:
1131: * There should be no context switches or memory protection changes
1132:
1133: * in the meantime.
1134:
1135: *
1136:
1137: * If called with mode == -1, returns...
1138:
1139: * -1 if mem prot is off -- no error, no action.
1140:
1141: * 0 if the pages are not all the same.
1142:
1143: * 1 if the pages are not all controlled by the page tables.
1144:
1145: *
1146:
1147: * When mode != -1, returns...
1148:
1149: * 0 for success (should never fail). There is little checking.
1150:
1151: * Calling with mode == 0 or 1 results in zero to spoof success, but in fact
1152:
1153: * this is an error. Mode is only really valid if (mode & 0x8000).
1154:
1155: */
1156:
1157:
1158:
1159: int
1160:
1161: prot_temp(loc,len,mode)
1162:
1163: ulong loc;
1164:
1165: ulong len;
1166:
1167: int mode;
1168:
1169: {
1170:
1171: int cookie;
1172:
1173:
1174:
1175: if (no_mem_prot) return -1;
1176:
1177:
1178:
1179: /* round start down to the previous page and len up to the next one. */
1180:
1181: loc &= ~MASKBITS;
1182:
1183: len = ROUND(len);
1184:
1185:
1186:
1187: if (mode == 0 || mode == 1) return 0; /* do nothing */
1188:
1189: if (mode == -1) {
1190:
1191: cookie = get_page_cookie(curproc->page_table,loc,len);
1192:
1193:
1194:
1195: /* if not all controlled, return status */
1196:
1197: if (cookie == 0 || cookie == 1) return cookie;
1198:
1199:
1200:
1201: mark_pages(curproc->page_table,loc,len,1,0,0,curproc);
1202:
1203:
1204:
1205: return cookie;
1206:
1207: }
1208:
1209: else {
1210:
1211: mark_pages(curproc->page_table,loc,len,
1212:
1213: mode&3,mode&4,mode&8,curproc);
1214:
1215: return 0;
1216:
1217: }
1218:
1219: }
1220:
1221:
1222:
1223: /*
1224:
1225: * init_page_table: fill in the page table for the indicated process. The
1226:
1227: * master page map is consulted for the modes of all pages, and the memory
1228:
1229: * region data structures are consulted to see if this process is the owner
1230:
1231: * of any of those tables.
1232:
1233: *
1234:
1235: * This also sets crp and tc in both ctxts of the process. If this is the
1236:
1237: * first call, then the CPU tc is cleared, the TT0 and TT1 regs are zapped,
1238:
1239: * and then this proc's crp and tc are loaded into it.
1240:
1241: */
1242:
1243:
1244:
1245: static short mmu_is_set_up = 0;
1246:
1247:
1248:
1249: void
1250:
1251: init_page_table(proc)
1252:
1253: PROC *proc;
1254:
1255: {
1256:
1257: long_desc *tptr;
1258:
1259: long_desc *tbl_a; /* top-level table */
1260:
1261: long_desc *tbl_b0; /* second level, handles $0 nybble */
1262:
1263: long_desc *tbl_bf; /* handles $F nybble */
1264:
1265: long_desc *tbl_c; /* temp pointer to start of 16MB */
1266:
1267: ulong p, q, r;
1268:
1269: ulong i, j, k;
1270:
1271: int g;
1272:
1273: MEMREGION **mr;
1274:
1275:
1276:
1277: if (no_mem_prot) return;
1278:
1279:
1280:
1281: if (proc->pid)
1282:
1283: TRACELOW(("init_page_table(proc=%lx, pid %d)",proc,proc->pid));
1284:
1285:
1286:
1287: assert(proc && proc->page_table);
1288:
1289:
1290:
1291: tptr = proc->page_table;
1292:
1293: tbl_a = tptr;
1294:
1295: tptr += TBL_SIZE;
1296:
1297: tbl_b0 = tptr;
1298:
1299: tptr += TBL_SIZE;
1300:
1301: tbl_bf = tptr;
1302:
1303: tptr += TBL_SIZE;
1304:
1305:
1306:
1307: /*
1308:
1309: * table A indexes by the first nybble: $0 and $F refer to their tables,
1310:
1311: * $1-$7 are uncontrolled, cacheable; $8-$E are uncontrolled, ci.
1312:
1313: */
1314:
1315:
1316:
1317: tbl_a[0].page_type = page_ptr;
1318:
1319: tbl_a[0].tbl_address = tbl_b0;
1320:
1321:
1322:
1323: for (i=1; i<0xf; i++) {
1324:
1325: if (i < 8) tbl_a[i].page_type = g_page;
1326:
1327: else tbl_a[i].page_type = g_ci_page;
1328:
1329: tbl_a[i].tbl_address = (long_desc *)(i << 28);
1330:
1331: }
1332:
1333:
1334:
1335: /* $F entry of table A refers to table BF */
1336:
1337: tbl_a[0xf].page_type = page_ptr;
1338:
1339: tbl_a[0xf].tbl_address = tbl_bf;
1340:
1341:
1342:
1343: /*
1344:
1345: * table B0: entry 0 is $00, the 16MB of ST address space.
1346:
1347: */
1348:
1349:
1350:
1351: tbl_b0[0].page_type = page_ptr;
1352:
1353: tbl_b0[0].tbl_address = tptr;
1354:
1355: tbl_c = tptr;
1356:
1357: tptr += TBL_SIZE;
1358:
1359:
1360:
1361: /* for each megabyte that is RAM, allocate a table */
1362:
1363: for (i = 0, k = 0, p = 0; p < mint_top_st; i++, p += 0x00100000L) {
1364:
1365: tbl_c[i].page_type = page_ptr;
1366:
1367: tbl_c[i].tbl_address = tptr;
1368:
1369:
1370:
1371: /* for each page in this megabyte, write a page entry */
1372:
1373: for (q = p, j = 0; j < 128; j++, q += 0x2000, k++) {
1374:
1375: tptr->page_type = *proto_page_type[global_mode_table[k]];
1376:
1377: tptr->tbl_address = (long_desc *)q;
1378:
1379: tptr++;
1380:
1381: }
1382:
1383: }
1384:
1385:
1386:
1387: /* now for each megabyte from mint_top_st to ROM, mark global */
1388:
1389: for ( ; p < 0x00E00000L; i++, p += 0x00100000L) {
1390:
1391: tbl_c[i].page_type = g_page;
1392:
1393: tbl_c[i].tbl_address = (long_desc *)p;
1394:
1395: }
1396:
1397:
1398:
1399: /* fill in the E and F tables: 00Ex is ROM, 00Fx is I/O */
1400:
1401: tbl_c[i].page_type = g_page;
1402:
1403: tbl_c[i].tbl_address = (long_desc *)p;
1404:
1405: i++, p += 0x00100000L;
1406:
1407: tbl_c[i].page_type = g_ci_page;
1408:
1409: tbl_c[i].tbl_address = (long_desc *)p;
1410:
1411:
1412:
1413: /* Done with tbl_c for 0th 16MB; go on to TT RAM */
1414:
1415:
1416:
1417: /*
1418:
1419: structure:
1420:
1421:
1422:
1423: for (i = each 16MB that has any TT RAM in it)
1424:
1425: allocate a table tbl_c, point tbl_b0[i] at it
1426:
1427: for (j = each 1MB that is RAM)
1428:
1429: allocate a table, point tbl_c[j] at it
1430:
1431: for (k = each page in the megabyte)
1432:
1433: fill in tbl_c[j][k] with page entry from global_mode_table
1434:
1435: for (j = the rest of the 16MB)
1436:
1437: set tbl_c[j] to "global, cacheable"
1438:
1439:
1440:
1441: for (i = the rest of the 16MBs from here to $7F)
1442:
1443: set tbl_b0[i] to "global, cacheable"
1444:
1445:
1446:
1447: for (i = the rest of the 16MBs from $80 up to but not incl. $FF)
1448:
1449: set tbl_b0[i] to "global, not cacheable"
1450:
1451: */
1452:
1453:
1454:
1455: /* i counts 16MBs */
1456:
1457: for (i = 1, p = 0x01000000L, g = 2048;
1458:
1459: p < mint_top_tt;
1460:
1461: p += SIXTEEN_MEG, i++) {
1462:
1463: tbl_b0[i].page_type = page_ptr;
1464:
1465: tbl_b0[i].tbl_address = tptr;
1466:
1467: tbl_c = tptr;
1468:
1469: tptr += TBL_SIZE;
1470:
1471:
1472:
1473: /* j counts MBs */
1474:
1475: for (j = 0, q = p; j < 16 && q < mint_top_tt; q += ONE_MEG, j++) {
1476:
1477: tbl_c[j].page_type = page_ptr;
1478:
1479: tbl_c[j].tbl_address = tptr;
1480:
1481: /* k counts pages (8K) */
1482:
1483: for (r = q, k = 0; k < 128; k++, r += 0x2000, g++) {
1484:
1485: tptr->page_type = *proto_page_type[global_mode_table[g]];
1486:
1487: tptr->tbl_address = (long_desc *)r;
1488:
1489: tptr++;
1490:
1491: }
1492:
1493: }
1494:
1495: for ( ; j < 16; j++, q += ONE_MEG) {
1496:
1497: /* fill in the rest of this 16MB */
1498:
1499: tbl_c[j].page_type = g_page;
1500:
1501: tbl_c[j].tbl_address = (long_desc *)q;
1502:
1503: }
1504:
1505: }
1506:
1507:
1508:
1509: /* fill in the rest of $00-$0F as cacheable */
1510:
1511: for ( ; i < 16; i++, p += SIXTEEN_MEG) {
1512:
1513: tbl_b0[i].page_type = g_page;
1514:
1515: tbl_b0[i].tbl_address = (long_desc *)p;
1516:
1517: }
1518:
1519:
1520:
1521: /* done with TT RAM in table b0; do table bf */
1522:
1523:
1524:
1525: /*
1526:
1527: * Table BF: translates addresses starting with $F. First 15 are
1528:
1529: * uncontrolled, cacheable; last one translates $FF, which
1530:
1531: * which shadows $00 (the 16MB ST address space). The rest
1532:
1533: * are uncontrolled, not cacheable.
1534:
1535: *
1536:
1537: * The table address of the copy has a 1 in the low (unused) bit, which
1538:
1539: * is a signal to the table dumper not to dump this, as it's a copy
1540:
1541: * of tbl_b0[0].
1542:
1543: */
1544:
1545:
1546:
1547: for (i=0; i<0xf; i++) {
1548:
1549: tbl_bf[i].page_type = g_ci_page;
1550:
1551: tbl_bf[i].tbl_address = (long_desc *)((i << 24) | 0xf0000000L);
1552:
1553: }
1554:
1555: tbl_bf[0xf] = tbl_b0[0];
1556:
1557: *(ulong *)(&(tbl_bf[0xf].tbl_address)) |= 1;
1558:
1559:
1560:
1561: proc->ctxt[0].crp.limit = 0x7fff; /* disable limit function */
1562:
1563: proc->ctxt[0].crp.dt = 3; /* points to valid 8-byte entries */
1564:
1565: proc->ctxt[0].crp.tbl_address = tbl_a;
1566:
1567: proc->ctxt[1].crp = proc->ctxt[0].crp;
1568:
1569: proc->ctxt[0].tc = tc;
1570:
1571: proc->ctxt[1].tc = tc;
1572:
1573:
1574:
1575: /*
1576:
1577: * OK, memory tables are now there as if you're a non-owner of every
1578:
1579: * page. Now for each region you ARE an owner of, mark with owner
1580:
1581: * modes.
1582:
1583: */
1584:
1585:
1586:
1587: mr = proc->mem;
1588:
1589: for (i=0; i < proc->num_reg; i++, mr++) {
1590:
1591: if (*mr) {
1592:
1593: mark_pages(proc->page_table,(*mr)->loc,(*mr)->len,1,0,0,proc);
1594:
1595: }
1596:
1597: }
1598:
1599:
1600:
1601: if (!mmu_is_set_up) {
1602:
1603: set_mmu(proc->ctxt[0].crp,proc->ctxt[0].tc);
1604:
1605: mmu_is_set_up = 1;
1606:
1607: }
1608:
1609: }
1610:
1611:
1612:
1613: /*
1614:
1615: * This routine is called when procfs detects that a process wants to be an
1616:
1617: * OS SPECIAL. The AES, SCRENMGR, and DESKTOP do this, and so does FSMGDOS
1618:
1619: * and possibly some other stuff. It has to re-mark every page in that
1620:
1621: * process' page table based on its new special status. The "special
1622:
1623: * status" is "you get global access to all of memory" and "everybody
1624:
1625: * gets Super access to yours." It is the caller's responsibility
1626:
1627: * to set proc's memflags, usually to (F_OS_SPECIAL | F_PROT_S).
1628:
1629: */
1630:
1631:
1632:
1633: void
1634:
1635: mem_prot_special(proc)
1636:
1637: PROC *proc;
1638:
1639: {
1640:
1641: MEMREGION **mr;
1642:
1643: int i;
1644:
1645:
1646:
1647: if (no_mem_prot) return;
1648:
1649:
1650:
1651: TRACE(("mem_prot_special(pid %d)",proc->pid));
1652:
1653:
1654:
1655: /*
1656:
1657: * This marks ALL memory, allocated or not, as accessible. When memory
1658:
1659: * is freed even F_OS_SPECIAL processes lose access to it. So one or
1660:
1661: * the other of these is a bug, depending on how you want it to work.
1662:
1663: */
1664:
1665: mark_pages(proc->page_table,0,mint_top_st,1,0,0,proc);
1666:
1667: if (mint_top_tt) {
1668:
1669: mark_pages(proc->page_table,
1670:
1671: 0x01000000L,
1672:
1673: mint_top_tt - 0x01000000L,
1674:
1675: 1,0,0,
1676:
1677: proc);
1678:
1679: }
1680:
1681:
1682:
1683: /*
1684:
1685: * In addition, mark all the pages the process already owns as "super"
1686:
1687: * in all other processes. Thus the "special" process can access all
1688:
1689: * of memory, and any process can access the "special" process' memory
1690:
1691: * when in super mode.
1692:
1693: */
1694:
1695:
1696:
1697: mr = proc->mem;
1698:
1699:
1700:
1701: for (i=0; i < proc->num_reg; i++, mr++) {
1702:
1703: if (*mr) {
1704:
1705: mark_region(*mr,PROT_S);
1706:
1707: }
1708:
1709: }
1710:
1711: }
1712:
1713:
1714:
1715: /*----------------------------------------------------------------------------
1716:
1717: * DEBUGGING SECTION
1718:
1719: *--------------------------------------------------------------------------*/
1720:
1721:
1722:
1723: static void
1724:
1725: _dump_tree(tbl,level)
1726:
1727: long_desc tbl;
1728:
1729: int level;
1730:
1731: {
1732:
1733: int i, j;
1734:
1735: long_desc *p;
1736:
1737: static char spaces[9] = " ";
1738:
1739:
1740:
1741: /* print the level and display the table descriptor */
1742:
1743: FORCE("\r%s s:%x wp:%x dt:%x a:%08lx",
1744:
1745: &spaces[8-(level*2)],
1746:
1747: tbl.page_type.s,
1748:
1749: tbl.page_type.wp,
1750:
1751: tbl.page_type.dt,
1752:
1753: tbl.tbl_address);
1754:
1755:
1756:
1757: if (tbl.page_type.dt == 3) {
1758:
1759: if (level == 0) {
1760:
1761: j = (1 << tc.tia);
1762:
1763: }
1764:
1765: else if (level == 1) {
1766:
1767: j = (1 << tc.tib);
1768:
1769: }
1770:
1771: else if (level == 2) {
1772:
1773: j = (1 << tc.tic);
1774:
1775: }
1776:
1777: else {
1778:
1779: j = (1 << tc.tid);
1780:
1781: }
1782:
1783:
1784:
1785: /* don't show table if it's the duplicate */
1786:
1787: if ((ulong)tbl.tbl_address & 1) return;
1788:
1789:
1790:
1791: ++level;
1792:
1793: p = tbl.tbl_address;
1794:
1795: for (i=0; i<j; i++, p++) {
1796:
1797: _dump_tree(*p,level);
1798:
1799: }
1800:
1801: }
1802:
1803: }
1804:
1805:
1806:
1807: static char modesym[] = { 'p', 'g', 's', 'r', 'i' };
1808:
1809:
1810:
1811: void
1812:
1813: QUICKDUMP()
1814:
1815: {
1816:
1817: char outstr[33];
1818:
1819: ulong i, j, end;
1820:
1821:
1822:
1823: if (no_mem_prot) return;
1824:
1825:
1826:
1827: FORCE("STRAM global table:");
1828:
1829: outstr[32] = '\0';
1830:
1831: end = mint_top_st / QUANTUM;
1832:
1833: for (i = 0; i < end; i += 32) {
1834:
1835: for (j=0; j<32; j++) {
1836:
1837: outstr[j] = modesym[global_mode_table[j+i]];
1838:
1839: }
1840:
1841: FORCE("%08lx: %s",i*8192L,outstr);
1842:
1843: }
1844:
1845:
1846:
1847: if (mint_top_tt) {
1848:
1849: FORCE("TTRAM global table:");
1850:
1851: end = mint_top_tt / QUANTUM;
1852:
1853: for (i = 2048; i < end; i += 32) {
1854:
1855: for (j=0; j<32; j++) {
1856:
1857: outstr[j] = modesym[global_mode_table[j+i]];
1858:
1859: }
1860:
1861: FORCE("%08lx: %s",i*8192L,outstr);
1862:
1863: }
1864:
1865: }
1866:
1867: }
1868:
1869:
1870:
1871: const char *berr_msg[] = {
1872:
1873: /* "........." */
1874:
1875: "private ",
1876:
1877: "global ", /* turned into "hardware" for violation reports */
1878:
1879: "super ",
1880:
1881: "readable ",
1882:
1883: "free ",
1884:
1885: "hardware " /* used when the memory is not controlled by us */
1886:
1887: };
1888:
1889:
1890:
1891: void
1892:
1893: report_buserr()
1894:
1895: {
1896:
1897: long_desc *tbl;
1898:
1899: const char *vmsg = NULL;
1900:
1901: short mode;
1902:
1903: ulong aa, pc;
1904:
1905: char alertbuf[5*32+16]; /* enough for an alert */
1906:
1907: char *aptr;
1908:
1909:
1910:
1911: if (no_mem_prot) return;
1912:
1913:
1914:
1915: tbl = (long_desc *)curproc->exception_tbl;
1916:
1917: aa = curproc->exception_addr;
1918:
1919: pc = curproc->exception_pc;
1920:
1921: if ((mint_top_tt && aa < mint_top_tt) || (aa < mint_top_st)) {
1922:
1923: mode = global_mode_table[(curproc->exception_addr >> 13)];
1924:
1925: if (mode == PROT_G) {
1926:
1927: /* page is global: obviously a hardware bus error */
1928:
1929: mode = 5;
1930:
1931: }
1932:
1933: }
1934:
1935: else {
1936:
1937: /* (addr is > mint_top_tt) set mode = 5 so we don't look for owners */
1938:
1939: mode = 5;
1940:
1941: }
1942:
1943: vmsg = berr_msg[mode];
1944:
1945:
1946:
1947: /* construct an AES alert box for this error:
1948:
1949: | PROCESS "buserrxx" KILLED: |
1950:
1951: | MEMORY VIOLATION. (PID 000) |
1952:
1953: | |
1954:
1955: | Type: ......... PC: pc...... |
1956:
1957: | Addr: ........ BP: ........ |
1958:
1959: */
1960:
1961:
1962:
1963: /* we play games to get around 128-char max for ksprintf */
1964:
1965: ksprintf(alertbuf,"[1][ PROCESS \"%s\" KILLED: |",curproc->name);
1966:
1967: aptr = alertbuf + strlen(alertbuf);
1968:
1969: ksprintf(aptr," MEMORY VIOLATION. (PID %03d) | |",curproc->pid);
1970:
1971: aptr = alertbuf + strlen(alertbuf);
1972:
1973: ksprintf(aptr," Type: %s PC: %08lx |",vmsg,pc);
1974:
1975: aptr = alertbuf + strlen(alertbuf);
1976:
1977: ksprintf(aptr," Addr: %08lx BP: %08lx ][ OK ]",aa,curproc->base);
1978:
1979: if (!_ALERT(alertbuf)) {
1980:
1981: /* this will call _alert again, but it will just fail again */
1982:
1983: ALERT("MEMORY VIOLATION: type=%s AA=%lx PC=%lx BP=%lx",
1984:
1985: vmsg,aa,pc,curproc->base);
1986:
1987: }
1988:
1989:
1990:
1991: if (curproc->pid == 0 || curproc->memflags & F_OS_SPECIAL) {
1992:
1993: /* the system is so thoroughly hosed that anything we try will
1994:
1995: * likely cause another bus error; so let's just hang up
1996:
1997: */
1998:
1999: FATAL("Operating system killed");
2000:
2001: }
2002:
2003: }
2004:
2005:
2006:
2007: /*
2008:
2009: * big_mem_dump is a biggie: for each page in the system, it
2010:
2011: * displays the PID of the (first) owner and the protection mode.
2012:
2013: * The output has three chars per page, and eight chars per line.
2014:
2015: * The first page of a region is marked with the mode, and the
2016:
2017: * rest with a space.
2018:
2019: *
2020:
2021: * Logic:
2022:
2023: for (mp = *core; mp; mp++) {
2024:
2025: for (each page of this region) {
2026:
2027: if (start of line) {
2028:
2029: output line starter;
2030:
2031: }
2032:
2033: if (start of region) {
2034:
2035: output mode of this page;
2036:
2037: determine owner;
2038:
2039: output owner;
2040:
2041: }
2042:
2043: else {
2044:
2045: output space;
2046:
2047: output owner;
2048:
2049: }
2050:
2051: }
2052:
2053: }
2054:
2055: */
2056:
2057:
2058:
2059: void
2060:
2061: BIG_MEM_DUMP(bigone,proc)
2062:
2063: int bigone;
2064:
2065: PROC *proc;
2066:
2067: {
2068:
2069: #ifndef NO_DEBUG_INFO
2070:
2071: char linebuf[128];
2072:
2073: char *lp = linebuf;
2074:
2075: MEMREGION *mp, **mr, **map;
2076:
2077: PROC *p;
2078:
2079: ulong loc;
2080:
2081: short owner = 0;
2082:
2083: short i;
2084:
2085: short first;
2086:
2087:
2088:
2089:
2090:
2091: if (no_mem_prot) return;
2092:
2093:
2094:
2095: for (map = core; map != 0; ((map == core) ? (map = alt) : (map = 0))) {
2096:
2097: FORCE("Annotated memory dump for %s",(map == core ? "core" : "alt"));
2098:
2099: first = 1;
2100:
2101: *linebuf = '\0';
2102:
2103: for (mp = *map; mp; mp = mp->next) {
2104:
2105: for (loc = mp->loc; loc < (mp->loc + mp->len); loc += EIGHT_K) {
2106:
2107: if (first || ((loc & 0x1ffff) == 0)) {
2108:
2109: if (*linebuf) FORCE(linebuf);
2110:
2111: ksprintf(linebuf,"\r%08lx: ",loc);
2112:
2113: lp = &linebuf[11];
2114:
2115: first = 0;
2116:
2117: }
2118:
2119: if (loc == mp->loc) {
2120:
2121: *lp++ = modesym[global_mode_table[loc / EIGHT_K]];
2122:
2123:
2124:
2125: for (p = proclist; p; p = p->gl_next) {
2126:
2127: if (p->mem) {
2128:
2129: mr = p->mem;
2130:
2131: for (i=0; i < p->num_reg; i++, mr++) {
2132:
2133: if (*mr == mp) {
2134:
2135: owner = p->pid;
2136:
2137: goto gotowner;
2138:
2139: }
2140:
2141: }
2142:
2143: }
2144:
2145: }
2146:
2147: owner = 000;
2148:
2149: gotowner:
2150:
2151: ksprintf(lp,"%03d",owner);
2152:
2153: lp += 3;
2154:
2155: }
2156:
2157: else {
2158:
2159: *lp++ = ' ';
2160:
2161: *lp++ = '-';
2162:
2163: *lp++ = '-';
2164:
2165: *lp++ = '-';
2166:
2167: *lp = '\0'; /* string is always null-terminated */
2168:
2169: }
2170:
2171: }
2172:
2173: }
2174:
2175: FORCE(linebuf);
2176:
2177: }
2178:
2179:
2180:
2181: if (bigone) {
2182:
2183: long_desc tbl;
2184:
2185:
2186:
2187: /* fill in tbl with the only parts used at the top level */
2188:
2189: tbl.page_type.dt = proc->ctxt[CURRENT].crp.dt;
2190:
2191: tbl.tbl_address = proc->ctxt[CURRENT].crp.tbl_address;
2192:
2193: _dump_tree(tbl,0);
2194:
2195: }
2196:
2197: #endif /* NO_DEBUG_INFO */
2198:
2199: }
2200:
2201:
2202:
2203:
2204:
2205: /*
2206:
2207: * Can the process "p" access the "nbytes" long
2208:
2209: * block of memory starting at "start"?
2210:
2211: * If it would be a legal access, the current
2212:
2213: * process is given temporary access via
2214:
2215: * prot_temp.
2216:
2217: * Returns a cookie like the one prot_temp
2218:
2219: * returns; if the process shouldn't have
2220:
2221: * access to the memory, returns 1.
2222:
2223: *
2224:
2225: * BUG: should actually read p's page table to
2226:
2227: * determine access
2228:
2229: */
2230:
2231:
2232:
2233: int
2234:
2235: mem_access_for(p, start, nbytes)
2236:
2237: PROC *p;
2238:
2239: ulong start;
2240:
2241: long nbytes;
2242:
2243: {
2244:
2245: MEMREGION **mr;
2246:
2247: int i;
2248:
2249:
2250:
2251: if (no_mem_prot) return -1;
2252:
2253: if (start >= (ulong)p && start+nbytes <= (ulong)(p+1))
2254:
2255: return -1;
2256:
2257: if (p == rootproc)
2258:
2259: goto win_and_mark;
2260:
2261:
2262:
2263: mr = p->mem;
2264:
2265: if (mr) {
2266:
2267: for (i = 0; i < p->num_reg; i++, mr++) {
2268:
2269: if (*mr) {
2270:
2271: if (((*mr)->loc <= start) &&
2272:
2273: ((*mr)->loc + (*mr)->len >= start + nbytes))
2274:
2275: goto win_and_mark;
2276:
2277: }
2278:
2279: }
2280:
2281: }
2282:
2283:
2284:
2285: return 0; /* we don't own this memory */
2286:
2287:
2288:
2289: win_and_mark:
2290:
2291: return prot_temp(start, nbytes, -1);
2292:
2293: }
2294:
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