1990/1212/port/fault.c (diff list | history)

1990/1202/sys/src/9/port/fault.c:6,16 – 1990/1212/sys/src/9/port/fault.c:6,15 (short | long | prev | next)
Created. rsc Fri Mar 4 12:44:25 2005
1990/0227		#include "ureg.h" #include "errno.h" void fault(Ureg *ur, int user, int code)
1990/1212		int fault(ulong addr, int read)
1990/0227		{ ulong addr, mmuvirt, mmuphys, n; extern char *excname[];
1990/1212		ulong mmuvirt, mmuphys, n;
1990/0227		Seg *s; PTE *opte, *pte, *npte; Orig *o;
1990/1202/sys/src/9/port/fault.c:18,51 – 1990/1212/sys/src/9/port/fault.c:17,37
1990/0227		Page *pg; int zeroed = 0, head = 1; int i;
1990/1212		KMap *k, *k1;
1990/0227		addr = ur->badvaddr; addr &= ~(BY2PG-1);                  s = seg(u->p, addr); if(s == 0){ if(addr>USTKTOP){ cant: if(user){ pprint("user %s badvaddr=0x%lux\n", excname[code], ur->badvaddr); pprint("status=0x%lux pc=0x%lux sp=0x%lux\n", ur->status, ur->pc, ur->sp); pexit("Suicide", 0); } print("kernel %s badvaddr=0x%lux\n", excname[code], ur->badvaddr); print("status=0x%lux pc=0x%lux sp=0x%lux\n", ur->status, ur->pc, ur->sp); u->p->state = MMUing; dumpregs(ur); panic("fault"); }
1990/1212		if(addr>USTKTOP) return -1;
1990/0227		s = &u->p->seg[SSEG];
1990/0821		if(s->o==0 || addr<s->maxva-USTACKSIZE || addr>=s->maxva)
1990/0227		goto cant;
1990/1212		return -1;
1990/0227		/* grow stack */ o = s->o; n = o->npte;
1990/0802		if(waserror()){ pprint("can't allocate stack page\n"); goto cant;
1990/1212		return -1;
1990/0802		}
1990/0227		growpte(o, (s->maxva-addr)>>PGSHIFT);
1990/0802		poperror();
1990/1202/sys/src/9/port/fault.c:58,65 – 1990/1212/sys/src/9/port/fault.c:44,51
1990/0227		o->va = addr; }else o = s->o; if((code==CTLBM || code==CTLBS) && (o->flag&OWRPERM)==0) goto cant;
1990/1212		if(!read && (o->flag&OWRPERM)==0) return -1;
1990/0227		lock(o); opte = &o->pte[(addr-o->va)>>PGSHIFT]; pte = opte;
1990/1202/sys/src/9/port/fault.c:92,99 – 1990/1212/sys/src/9/port/fault.c:78,87
1990/0227		if(n > BY2PG) n = BY2PG; pg = newpage(1, o, addr);
1990/1212		k = kmap(pg);
1990/0227		qlock(o->chan); if(waserror()){
1990/1212		kunmap(k);
1990/0227		qunlock(o->chan); pg->o = 0; pg->ref--;
1990/1202/sys/src/9/port/fault.c:100,114 – 1990/1212/sys/src/9/port/fault.c:88,102
1990/1113		pexit("load i/o error", 0);
1990/0227		} o->chan->offset = (addr-o->va) + o->minca; l = (char*)(pg->pa|KZERO);
1990/1212		l = (char*)VA(k);
1990/0227		if((*devtab[o->chan->type].read)(o->chan, l, n) != n)
1990/11211		error(Eioload);
1990/0227		qunlock(o->chan); poperror(); /* BUG: if was first page of bss, move to data */ if(n<BY2PG) memset(l+n, 0, BY2PG-n); lock(o);
1990/1212		kunmap(k); poperror();
1990/0227		opte = &o->pte[(addr-s->minva)>>PGSHIFT]; /* could move */ pte = opte; if(pte->page == 0){
1990/1202/sys/src/9/port/fault.c:121,129 – 1990/1212/sys/src/9/port/fault.c:109,117
1990/0227		} } /* * Copy on reference
1990/1212		* Copy on reference (conf.copymode==1) or write (conf.copymode==0)
1990/0227		*/ if((o->flag & OWRPERM)
1990/1212		if((o->flag & OWRPERM) && (conf.copymode || !read)
1990/0227		&& ((head && ((o->flag&OPURE) || o->nproc>1)) || (!head && pte->page->ref>1))){
1990/1202/sys/src/9/port/fault.c:173,179 – 1990/1212/sys/src/9/port/fault.c:161,171
1990/0227		opte->page = 0; }else{ /* copy page */ pte->page = newpage(1, o, addr); memcpy((void*)(pte->page->pa|KZERO), (void*)(pg->pa|KZERO), BY2PG);
1990/1212		k = kmap(pte->page); k1 = kmap(pg); memcpy((void*)VA(k), (void*)VA(k1), BY2PG); kunmap(k); kunmap(k1);
1990/0227		if(pg->ref <= 1) panic("pg->ref <= 1"); pg->ref--;
1990/1202/sys/src/9/port/fault.c:181,187 – 1990/1212/sys/src/9/port/fault.c:173,179
1990/0227		easy: mmuphys = PTEWRITE; }else{ mmuphys = 0;
1990/1212		mmuphys = PTERONLY;
1990/0227		if(o->flag & OWRPERM) if(o->flag & OPURE){ if(!head && pte->page->ref==1)
1990/1202/sys/src/9/port/fault.c:192,198 – 1990/1212/sys/src/9/port/fault.c:184,190
1990/0227		mmuphys = PTEWRITE; } mmuvirt = addr; mmuphys |= pte->page->pa | PTEVALID;
1990/1212		mmuphys |= PPN(pte->page->pa) | PTEVALID;
1990/0227		usepage(pte->page, 1); if(pte->page->va != addr) panic("wrong addr in tail %lux %lux", pte->page->va, addr);
1990/1202/sys/src/9/port/fault.c:203,208 – 1990/1212/sys/src/9/port/fault.c:195,201
1990/0227		} unlock(o); putmmu(mmuvirt, mmuphys);
1990/1212		return 0;
1990/0227		} /*
1990/1202/sys/src/9/port/fault.c:232,246 – 1990/1212/sys/src/9/port/fault.c:225,230
1990/0617		len -= s->maxva - addr; addr = s->maxva; goto Again;
1990/0227		} }                  void evenaddr(ulong addr) { if(addr & 3){
1990/1110		postnote(u->p, 1, "sys: odd address", NDebug);
1990/11211		error(Ebadarg);
1990/0227		} }