kernel: fix physical segment handling

ignore physical segments in mcountseg() and mfreeseg(). physical
segments are not backed by user pages, and doing putpage() on
physical segment pages in mfreeseg() is an error.

do now allow physical segemnts to be resized. the segment size
is only checked in segattach() to be within the physical segment!

ignore physical segments in portcountpagerefs() as pagenumber()
does not work on the malloced page structures of a physical segment.

get rid of Physseg.pgalloc() and Physseg.pgfree() indirection as
this was never used and if theres a need to do more efficient
allocation, it should be done in a portable way.

1 files changed, 7 insertions, 16 deletions

diff --git a/sys/src/9/port/page.c b/sys/src/9/port/page.c
index dcd701267..0061ed658 100644
--- a/sys/src/9/port/page.c
+++ b/sys/src/9/port/page.c
@@ -384,23 +384,11 @@ ptealloc(void)
 void
 freepte(Segment *s, Pte *p)
 {
-	void (*fn)(Page*);
-	Page **pg, **ptop;
+	Page **pg;
 
 	switch(s->type&SG_TYPE) {
 	case SG_PHYSICAL:
-		fn = s->pseg->pgfree;
-		ptop = &p->pages[PTEPERTAB];
-		if(fn != nil) {
-			for(pg = p->pages; pg < ptop; pg++) {
-				if(*pg == nil)
-					continue;
-				(*fn)(*pg);
-				*pg = nil;
-			}
-			break;
-		}
-		for(pg = p->pages; pg < ptop; pg++) {
+		for(pg = p->first; pg <= p->last; pg++) {
 			if(*pg != nil) {
 				if(decref(*pg) == 0)
 					free(*pg);
@@ -409,11 +397,12 @@ freepte(Segment *s, Pte *p)
 		}
 		break;
 	default:
-		for(pg = p->first; pg <= p->last; pg++)
+		for(pg = p->first; pg <= p->last; pg++) {
 			if(*pg != nil) {
 				putpage(*pg);
 				*pg = nil;
 			}
+		}
 	}
 	free(p);
 }
@@ -483,7 +472,7 @@ portcountpagerefs(ulong *ref, int print)
 		p = proctab(i);
 		for(j=0; j<NSEG; j++){
 			s = p->seg[j];
-			if(s)
+			if(s != nil)
 				s->mark = 0;
 		}
 	}
@@ -493,6 +482,8 @@ portcountpagerefs(ulong *ref, int print)
 			s = p->seg[j];
 			if(s == nil || s->mark++)
 				continue;
+			if((s->type&SG_TYPE) == SG_PHYSICAL)
+				continue;
 			ns++;
 			for(k=0; k<s->mapsize; k++){
 				pte = s->map[k];