Make VM fix up memory for kernel that crosses region boundaries

too.

Add a test to make this happen (triggers a vm panic before this commit).

servers/vm/i386/pagetable.c

@@ -711,9 +711,6 @@ PUBLIC void pt_init(phys_bytes usedlimit)
 	/* We have to make mappings up till here. */
 	free_pde = id_map_high_pde+1;
 
-	printf("map high pde: %d for limit: 0x%lx\n",
-		id_map_high_pde, usedlimit);
-
         /* Initial (current) range of our virtual address space. */
         lo = CLICK2ABS(vmp->vm_arch.vm_seg[T].mem_phys);
         hi = CLICK2ABS(vmp->vm_arch.vm_seg[S].mem_phys +

servers/vm/mmap.c

@@ -72,7 +72,8 @@ PUBLIC int do_mmap(message *m)
 			len += VM_PAGE_SIZE - (len % VM_PAGE_SIZE);
 
 		if(!(vr = map_page_region(vmp,
-			arch_vir2map(vmp, vmp->vm_stacktop),
+			arch_vir2map(vmp,
+				m->VMM_ADDR ? m->VMM_ADDR : vmp->vm_stacktop),
 			VM_DATATOP, len, MAP_NONE, vrflags, mfflags))) {
 			return ENOMEM;
 		}

servers/vm/pagefaults.c

@@ -62,21 +62,12 @@ PUBLIC void do_pagefaults(void)
 		vir_bytes offset;
 		int p, wr = PFERR_WRITE(err);
 
-#if 0
-		printf("VM: pagefault: ep %d 0x%lx %s\n", 
-			ep, arch_map2vir(vmp, addr), pf_errstr(err));
-#endif
-
 		if(vm_isokendpt(ep, &p) != OK)
 			vm_panic("do_pagefaults: endpoint wrong", ep);
 
 		vmp = &vmproc[p];
 		vm_assert(vmp->vm_flags & VMF_INUSE);
 
-#if 0
-		map_printmap(vmp);
-#endif
-
 		/* See if address is valid at all. */
 		if(!(region = map_lookup(vmp, addr))) {
 			vm_assert(PFERR_NOPAGE(err));
@@ -125,14 +116,6 @@ PUBLIC void do_pagefaults(void)
 				vm_panic("do_pagefaults: sys_vmctl failed", ep);
 			continue;
 		}
-#if 0
-		printf("VM: map_pf done; ep %d 0x%lx %s\n", 
-			ep, arch_map2vir(vmp, addr), pf_errstr(err));
-
-
-		printf("VM: handling pagefault OK: %d addr 0x%lx %s\n", 
-			ep, arch_map2vir(vmp, addr), pf_errstr(err));
-#endif
 
 		/* Pagefault is handled, so now reactivate the process. */
 		if((s=sys_vmctl(ep, VMCTL_CLEAR_PAGEFAULT, r)) != OK)
@@ -167,11 +150,6 @@ PUBLIC void do_memory(void)
 
 		if(sys_vmctl(requestor, VMCTL_MEMREQ_REPLY, r) != OK)
 			vm_panic("do_memory: sys_vmctl failed", r);
-
-#if 0
-		printf("VM: handling memory request %d done OK\n",
-			who);
-#endif
 	}
 }
 
@@ -179,12 +157,7 @@ int handle_memory(struct vmproc *vmp, vir_bytes mem, vir_bytes len, int wrflag)
 {
 	struct vir_region *region;
 	vir_bytes o;
-	int r;
+	vir_bytes v;
-
-#if 0
-	printf("VM: handling memory request: %d, 0x%lx-0x%lx, wr %d\n",
-		vmp->vm_endpoint, mem, mem+len, wrflag);
-#endif
 
 	/* Page-align memory and length. */
 	o = mem % VM_PAGE_SIZE;
@@ -193,31 +166,39 @@ int handle_memory(struct vmproc *vmp, vir_bytes mem, vir_bytes len, int wrflag)
 	o = len % VM_PAGE_SIZE;
 	if(o > 0) len += VM_PAGE_SIZE - o;
 
-	if(!(region = map_lookup(vmp, mem))) {
+	while(len > 0) {
-		map_printmap(vmp);
+		int r;
-		printf("VM: do_memory: memory doesn't exist\n");
+		if(!(region = map_lookup(vmp, mem))) {
-		r = EFAULT;
+			map_printmap(vmp);
-	} else if(mem + len > region->vaddr + region->length) {
+			printf("VM: do_memory: memory doesn't exist\n");
-		vm_assert(region->vaddr <= mem);
+			r = EFAULT;
-		vm_panic("do_memory: not contained", NO_NUM);
+		} else if(!(region->flags & VR_WRITABLE) && wrflag) {
-	} else if(!(region->flags & VR_WRITABLE) && wrflag) {
+			printf("VM: do_memory: write to unwritable map\n");
-		printf("VM: do_memory: write to unwritable map\n");
+			r = EFAULT;
-		r = EFAULT;
+		} else {
-	} else {
+			vir_bytes offset, sublen;
-		vir_bytes offset;
+			vm_assert(region->vaddr <= mem);
-		vm_assert(region->vaddr <= mem);
+			vm_assert(!(region->flags & VR_NOPF));
-		vm_assert(!(region->flags & VR_NOPF));
+			vm_assert(!(region->vaddr % VM_PAGE_SIZE));
-		vm_assert(!(region->vaddr % VM_PAGE_SIZE));
+			offset = mem - region->vaddr;
-		offset = mem - region->vaddr;
+			sublen = len;
+			if(offset + sublen > region->length)
+				sublen = region->length - offset;
+	
+			r = map_handle_memory(vmp, region, offset,
+				sublen, wrflag);
 
-		r = map_handle_memory(vmp, region, offset, len, wrflag);
+			len -= sublen;
+			mem += sublen;
+		}
+	
+		if(r != OK) {
+			printf("VM: memory range 0x%lx-0x%lx not available in %d\n",
+				arch_map2vir(vmp, mem), arch_map2vir(vmp, mem+len),
+				vmp->vm_endpoint);
+			return r;
+		}
 	}
 
-	if(r != OK) {
+	return OK;
-		printf("VM: memory range 0x%lx-0x%lx not available in %d\n",
-			arch_map2vir(vmp, mem), arch_map2vir(vmp, mem+len),
-			vmp->vm_endpoint);
-	}
-
-	return r;
 }

servers/vm/region.c

@@ -898,6 +898,7 @@ int write;
 	physr_start_iter(region->phys, &it, where, AVL_EQUAL);	\
 	what = physr_get_iter(&it); \
 	if(!what)  vm_panic("thing missing", NO_NUM); \
+	if(what->offset != where) vm_panic("thing wrong", NO_NUM);	\
 }
 
 	FREE_RANGE_HERE(NULL, physr);
@@ -908,8 +909,8 @@ int write;
 			physr_incr_iter(&iter);
 			physr = physr_get_iter(&iter);
 
+			FREE_RANGE_HERE(NULL, physr);
 			if(physr) {
-				FREE_RANGE_HERE(NULL, physr);
 				RESET_ITER(iter, physr->offset, physr);
 			}
 		}
@@ -957,7 +958,11 @@ int write;
 
 	SANITYCHECK(SCL_FUNCTIONS);
 
-	vm_assert(changes > 0);
+	if(changes < 1) {
+		printf("region start at 0x%lx offset 0x%lx len 0x%lx write %d\n", 
+			region->vaddr, offset, length, write);
+		vm_panic("no changes in map_handle_memory", NO_NUM);
+	}
 
 #if SANITYCHECKS
 	if(OK != pt_checkrange(&vmp->vm_pt, region->vaddr+offset, length, write)) {

test/Makefile

@@ -8,7 +8,7 @@ OBJ=	test1  test2  test3  test4  test5  test6  test7  test8  test9  \
 	       test21 test22 test23        test25 test26 test27 test28 test29 \
 	test30 test31 test32        test34 test35 test36 test37 test38 \
 	test39 t10a t11a t11b test40 t40a t40b t40c t40d t40e t40f test41 \
-	test42 
+	test42 test44
 
 BIGOBJ=  test20 test24
 ROOTOBJ= test11 test33 test43
@@ -84,3 +84,4 @@ t40f: t40f.c
 test41: test41.c
 test42: test42.c
 test43: test43.c
+test44: test44.c

test/run

@@ -18,7 +18,7 @@ echo " "
 # Run all the tests, keeping track of who failed.
 for i in  1  2  3  4  5  6  7  8  9 10 11 12 13 14 15 16 17 18 19 20 \
          21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 \
-         41 42 43 sh1.sh sh2.sh
+         41 42 43 44 sh1.sh sh2.sh
 do total=`expr $total + 1`
    FAIL=0
    if [ $USER = root -a \( $i = 11 -o $i = 33 \) ]