Changes in kernel/generic/src/mm/as.c [a35b458:1b20da0] in mainline

File:

• kernel/generic/src/mm/as.c (modified) (117 diffs)

kernel/generic/src/mm/as.c

@@ -114 +114 @@
 {
         as_t *as = (as_t *) obj;
-
+        
         link_initialize(&as->inactive_as_with_asid_link);
         mutex_initialize(&as->lock, MUTEX_PASSIVE);
-
+        
         return as_constructor_arch(as, flags);
 }
@@ -130 +130 @@
 {
         as_arch_init();
-
+        
         as_cache = slab_cache_create("as_t", sizeof(as_t), 0,
             as_constructor, as_destructor, SLAB_CACHE_MAGDEFERRED);
-
+        
         AS_KERNEL = as_create(FLAG_AS_KERNEL);
         if (!AS_KERNEL)
                 panic("Cannot create kernel address space.");
-
+        
         /*
          * Make sure the kernel address space
@@ -155 +155 @@
         as_t *as = (as_t *) slab_alloc(as_cache, 0);
         (void) as_create_arch(as, 0);
-
+        
         btree_create(&as->as_area_btree);
-
+        
         if (flags & FLAG_AS_KERNEL)
                 as->asid = ASID_KERNEL;
         else
                 as->asid = ASID_INVALID;
-
+        
         atomic_set(&as->refcount, 0);
         as->cpu_refcount = 0;
-
+        
 #ifdef AS_PAGE_TABLE
         as->genarch.page_table = page_table_create(flags);
@@ -171 +171 @@
         page_table_create(flags);
 #endif
-
+        
         return as;
 }
@@ -188 +188 @@
 {
         DEADLOCK_PROBE_INIT(p_asidlock);
-
+        
         assert(as != AS);
         assert(atomic_get(&as->refcount) == 0);
-
+        
         /*
          * Since there is no reference to this address space, it is safe not to
          * lock its mutex.
          */
-
+        
         /*
          * We need to avoid deadlock between TLB shootdown and asidlock.
@@ -206 +206 @@
         preemption_disable();
         ipl_t ipl = interrupts_read();
-
+        
 retry:
         interrupts_disable();
@@ -214 +214 @@
                 goto retry;
         }
-
+        
         /* Interrupts disabled, enable preemption */
         preemption_enable();
-
+        
         if ((as->asid != ASID_INVALID) && (as != AS_KERNEL)) {
                 if (as->cpu_refcount == 0)
                         list_remove(&as->inactive_as_with_asid_link);
-
+                
                 asid_put(as->asid);
         }
-
+        
         spinlock_unlock(&asidlock);
         interrupts_restore(ipl);
-
-
+        
+        
         /*
          * Destroy address space areas of the address space.
@@ -237 +237 @@
         while (cond) {
                 assert(!list_empty(&as->as_area_btree.leaf_list));
-
+                
                 btree_node_t *node =
                     list_get_instance(list_first(&as->as_area_btree.leaf_list),
                     btree_node_t, leaf_link);
-
+                
                 if ((cond = node->keys))
                         as_area_destroy(as, node->key[0]);
         }
-
+        
         btree_destroy(&as->as_area_btree);
-
+        
 #ifdef AS_PAGE_TABLE
         page_table_destroy(as->genarch.page_table);
@@ -253 +253 @@
         page_table_destroy(NULL);
 #endif
-
+        
         slab_free(as_cache, as);
 }
@@ -307 +307 @@
         if (overflows_into_positive(addr, P2SZ(count)))
                 return false;
-
+        
         /*
          * We don't want any area to have conflicts with NULL page.
@@ -328 +328 @@
                         return false;
         }
-
+        
         /* First, check the two border cases. */
         btree_node_t *node =
@@ -334 +334 @@
         if (node) {
                 area = (as_area_t *) node->value[node->keys - 1];
-
+                
                 if (area != avoid) {
                         mutex_lock(&area->lock);
@@ -346 +346 @@
                         int const gp = (guarded ||
                             (area->flags & AS_AREA_GUARD)) ? 1 : 0;
-
+                        
                         /*
                          * The area comes from the left neighbour node, which
@@ -358 +358 @@
                                 return false;
                         }
-
+                        
                         mutex_unlock(&area->lock);
                 }
         }
-
+        
         node = btree_leaf_node_right_neighbour(&as->as_area_btree, leaf);
         if (node) {
                 area = (as_area_t *) node->value[0];
-
+                
                 if (area != avoid) {
                         int gp;
@@ -382 +382 @@
                                 gp--;
                         }
-
+                        
                         if (overlaps(addr, P2SZ(count + gp), area->base,
                             P2SZ(area->pages))) {
@@ -388 +388 @@
                                 return false;
                         }
-
+                        
                         mutex_unlock(&area->lock);
                 }
         }
-
+        
         /* Second, check the leaf node. */
         btree_key_t i;
@@ -399 +399 @@
                 int agp;
                 int gp;
-
+                
                 if (area == avoid)
                         continue;
-
+                
                 mutex_lock(&area->lock);
 
@@ -421 +421 @@
                         return false;
                 }
-
+                
                 mutex_unlock(&area->lock);
         }
-
+        
         /*
          * So far, the area does not conflict with other areas.
@@ -434 +434 @@
                     addr, P2SZ(count));
         }
-
+        
         return true;
 }
@@ -456 +456 @@
 {
         assert(mutex_locked(&as->lock));
-
+        
         if (size == 0)
                 return (uintptr_t) -1;
-
+        
         /*
          * Make sure we allocate from page-aligned
@@ -465 +465 @@
          * each step.
          */
-
+        
         size_t pages = SIZE2FRAMES(size);
-
+        
         /*
          * Find the lowest unmapped address aligned on the size
          * boundary, not smaller than bound and of the required size.
          */
-
+        
         /* First check the bound address itself */
         uintptr_t addr = ALIGN_UP(bound, PAGE_SIZE);
@@ -486 +486 @@
                         return addr;
         }
-
+        
         /* Eventually check the addresses behind each area */
         list_foreach(as->as_area_btree.leaf_list, leaf_link, btree_node_t, node) {
-
+                
                 for (btree_key_t i = 0; i < node->keys; i++) {
                         as_area_t *area = (as_area_t *) node->value[i];
-
+                        
                         mutex_lock(&area->lock);
-
+                        
                         addr =
                             ALIGN_UP(area->base + P2SZ(area->pages), PAGE_SIZE);
@@ -508 +508 @@
                             ((addr >= bound) && (addr >= area->base) &&
                             (check_area_conflicts(as, addr, pages, guarded, area)));
-
+                        
                         mutex_unlock(&area->lock);
-
+                        
                         if (avail)
                                 return addr;
                 }
         }
-
+        
         /* No suitable address space area found */
         return (uintptr_t) -1;
@@ -530 +530 @@
 {
         bool dealloc = false;
-
+        
         mutex_lock(&sh_info->lock);
         assert(sh_info->refcount);
-
+        
         if (--sh_info->refcount == 0) {
                 dealloc = true;
-
+                
                 /*
                  * Now walk carefully the pagemap B+tree and free/remove
@@ -544 +544 @@
                     btree_node_t, node) {
                         btree_key_t i;
-
+                        
                         for (i = 0; i < node->keys; i++)
                                 frame_free((uintptr_t) node->value[i], 1);
                 }
-
+                
         }
         mutex_unlock(&sh_info->lock);
-
+        
         if (dealloc) {
                 if (sh_info->backend && sh_info->backend->destroy_shared_data) {
@@ -588 +588 @@
         if ((*base != (uintptr_t) AS_AREA_ANY) && !IS_ALIGNED(*base, PAGE_SIZE))
                 return NULL;
-
+        
         if (size == 0)
                 return NULL;
 
         size_t pages = SIZE2FRAMES(size);
-
+        
         /* Writeable executable areas are not supported. */
         if ((flags & AS_AREA_EXEC) && (flags & AS_AREA_WRITE))
@@ -599 +599 @@
 
         bool const guarded = flags & AS_AREA_GUARD;
-
+        
         mutex_lock(&as->lock);
-
+        
         if (*base == (uintptr_t) AS_AREA_ANY) {
                 *base = as_get_unmapped_area(as, bound, size, guarded);
@@ -619 +619 @@
                 return NULL;
         }
-
+        
         as_area_t *area = (as_area_t *) malloc(sizeof(as_area_t), 0);
-
+        
         mutex_initialize(&area->lock, MUTEX_PASSIVE);
-
+        
         area->as = as;
         area->flags = flags;
@@ -632 +632 @@
         area->backend = backend;
         area->sh_info = NULL;
-
+        
         if (backend_data)
                 area->backend_data = *backend_data;
@@ -655 +655 @@
 
                 area->sh_info = si;
-
+        
                 if (area->backend && area->backend->create_shared_data) {
                         if (!area->backend->create_shared_data(area)) {
@@ -679 +679 @@
         btree_insert(&as->as_area_btree, *base, (void *) area,
             NULL);
-
+        
         mutex_unlock(&as->lock);
-
+        
         return area;
 }
@@ -697 +697 @@
 {
         assert(mutex_locked(&as->lock));
-
+        
         btree_node_t *leaf;
         as_area_t *area = (as_area_t *) btree_search(&as->as_area_btree, va,
@@ -706 +706 @@
                 return area;
         }
-
+        
         /*
          * Search the leaf node and the rightmost record of its left neighbour
@@ -712 +712 @@
          * space area found there.
          */
-
+        
         /* First, search the leaf node itself. */
         btree_key_t i;
-
+        
         for (i = 0; i < leaf->keys; i++) {
                 area = (as_area_t *) leaf->value[i];
-
+                
                 mutex_lock(&area->lock);
 
@@ -724 +724 @@
                     (va <= area->base + (P2SZ(area->pages) - 1)))
                         return area;
-
+                
                 mutex_unlock(&area->lock);
         }
-
+        
         /*
          * Second, locate the left neighbour and test its last record.
@@ -736 +736 @@
         if (lnode) {
                 area = (as_area_t *) lnode->value[lnode->keys - 1];
-
+                
                 mutex_lock(&area->lock);
-
+                
                 if (va <= area->base + (P2SZ(area->pages) - 1))
                         return area;
-
+                
                 mutex_unlock(&area->lock);
         }
-
+        
         return NULL;
 }
@@ -766 +766 @@
 
         mutex_lock(&as->lock);
-
+        
         /*
          * Locate the area.
@@ -784 +784 @@
                 return ENOTSUP;
         }
-
+        
         mutex_lock(&area->sh_info->lock);
         if (area->sh_info->shared) {
@@ -797 +797 @@
         }
         mutex_unlock(&area->sh_info->lock);
-
+        
         size_t pages = SIZE2FRAMES((address - area->base) + size);
         if (!pages) {
@@ -807 +807 @@
                 return EPERM;
         }
-
+        
         if (pages < area->pages) {
                 uintptr_t start_free = area->base + P2SZ(pages);
-
+                
                 /*
                  * Shrinking the area.
                  * No need to check for overlaps.
                  */
-
+                
                 page_table_lock(as, false);
-
+                
                 /*
                  * Remove frames belonging to used space starting from
@@ -828 +828 @@
                 while (cond) {
                         assert(!list_empty(&area->used_space.leaf_list));
-
+                        
                         btree_node_t *node =
                             list_get_instance(list_last(&area->used_space.leaf_list),
                             btree_node_t, leaf_link);
-
+                        
                         if ((cond = (node->keys != 0))) {
                                 uintptr_t ptr = node->key[node->keys - 1];
@@ -838 +838 @@
                                     (size_t) node->value[node->keys - 1];
                                 size_t i = 0;
-
+                                
                                 if (overlaps(ptr, P2SZ(node_size), area->base,
                                     P2SZ(pages))) {
-
+                                        
                                         if (ptr + P2SZ(node_size) <= start_free) {
                                                 /*
@@ -850 +850 @@
                                                 break;
                                         }
-
+                                        
                                         /*
                                          * Part of the interval corresponding
@@ -856 +856 @@
                                          * address space area.
                                          */
-
+                                        
                                         /* We are almost done */
                                         cond = false;
@@ -871 +871 @@
                                                 panic("Cannot remove used space.");
                                 }
-
+                                
                                 /*
                                  * Start TLB shootdown sequence.
@@ -887 +887 @@
                                     as->asid, area->base + P2SZ(pages),
                                     area->pages - pages);
-
+                
                                 for (; i < node_size; i++) {
                                         pte_t pte;
                                         bool found = page_mapping_find(as,
                                             ptr + P2SZ(i), false, &pte);
-
+                                        
                                         assert(found);
                                         assert(PTE_VALID(&pte));
                                         assert(PTE_PRESENT(&pte));
-
+                                        
                                         if ((area->backend) &&
                                             (area->backend->frame_free)) {
@@ -903 +903 @@
                                                     PTE_GET_FRAME(&pte));
                                         }
-
+                                        
                                         page_mapping_remove(as, ptr + P2SZ(i));
                                 }
-
+                
                                 /*
                                  * Finish TLB shootdown sequence.
                                  */
-
+                
                                 tlb_invalidate_pages(as->asid,
                                     area->base + P2SZ(pages),
                                     area->pages - pages);
-
+                
                                 /*
                                  * Invalidate software translation caches
@@ -944 +944 @@
                 }
         }
-
+        
         if (area->backend && area->backend->resize) {
                 if (!area->backend->resize(area, pages)) {
@@ -952 +952 @@
                 }
         }
-
+        
         area->pages = pages;
-
+        
         mutex_unlock(&area->lock);
         mutex_unlock(&as->lock);
-
+        
         return 0;
 }
@@ -972 +972 @@
 {
         mutex_lock(&as->lock);
-
+        
         as_area_t *area = find_area_and_lock(as, address);
         if (!area) {
@@ -981 +981 @@
         if (area->backend && area->backend->destroy)
                 area->backend->destroy(area);
-
+        
         uintptr_t base = area->base;
-
+        
         page_table_lock(as, false);
-
+        
         /*
          * Start TLB shootdown sequence.
@@ -991 +991 @@
         ipl_t ipl = tlb_shootdown_start(TLB_INVL_PAGES, as->asid, area->base,
             area->pages);
-
+        
         /*
          * Visit only the pages mapped by used_space B+tree.
@@ -998 +998 @@
             node) {
                 btree_key_t i;
-
+                
                 for (i = 0; i < node->keys; i++) {
                         uintptr_t ptr = node->key[i];
                         size_t size;
-
+                        
                         for (size = 0; size < (size_t) node->value[i]; size++) {
                                 pte_t pte;
                                 bool found = page_mapping_find(as,
                                      ptr + P2SZ(size), false, &pte);
-
+                                
                                 assert(found);
                                 assert(PTE_VALID(&pte));
                                 assert(PTE_PRESENT(&pte));
-
+                                
                                 if ((area->backend) &&
                                     (area->backend->frame_free)) {
@@ -1018 +1018 @@
                                             PTE_GET_FRAME(&pte));
                                 }
-
+                                
                                 page_mapping_remove(as, ptr + P2SZ(size));
                         }
                 }
         }
-
+        
         /*
          * Finish TLB shootdown sequence.
          */
-
+        
         tlb_invalidate_pages(as->asid, area->base, area->pages);
-
+        
         /*
          * Invalidate potential software translation caches
@@ -1036 +1036 @@
         as_invalidate_translation_cache(as, area->base, area->pages);
         tlb_shootdown_finalize(ipl);
-
+        
         page_table_unlock(as, false);
-
+        
         btree_destroy(&area->used_space);
-
+        
         area->attributes |= AS_AREA_ATTR_PARTIAL;
-
+        
         sh_info_remove_reference(area->sh_info);
-
+        
         mutex_unlock(&area->lock);
-
+        
         /*
          * Remove the empty area from address space.
          */
         btree_remove(&as->as_area_btree, base, NULL);
-
+        
         free(area);
-
+        
         mutex_unlock(&as->lock);
         return 0;
@@ -1098 +1098 @@
                 return ENOENT;
         }
-
+        
         if (!src_area->backend->is_shareable(src_area)) {
                 /*
@@ -1107 +1107 @@
                 return ENOTSUP;
         }
-
+        
         size_t src_size = P2SZ(src_area->pages);
         unsigned int src_flags = src_area->flags;
         mem_backend_t *src_backend = src_area->backend;
         mem_backend_data_t src_backend_data = src_area->backend_data;
-
+        
         /* Share the cacheable flag from the original mapping */
         if (src_flags & AS_AREA_CACHEABLE)
                 dst_flags_mask |= AS_AREA_CACHEABLE;
-
+        
         if ((src_size != acc_size) ||
             ((src_flags & dst_flags_mask) != dst_flags_mask)) {
@@ -1123 +1123 @@
                 return EPERM;
         }
-
+        
         /*
          * Now we are committed to sharing the area.
@@ -1130 +1130 @@
          */
         share_info_t *sh_info = src_area->sh_info;
-
+        
         mutex_lock(&sh_info->lock);
         sh_info->refcount++;
@@ -1144 +1144 @@
                 src_area->backend->share(src_area);
         }
-
+        
         mutex_unlock(&src_area->lock);
         mutex_unlock(&src_as->lock);
-
+        
         /*
          * Create copy of the source address space area.
@@ -1164 +1164 @@
                  */
                 sh_info_remove_reference(sh_info);
-
+                
                 return ENOMEM;
         }
-
+        
         /*
          * Now the destination address space area has been
@@ -1179 +1179 @@
         mutex_unlock(&dst_area->lock);
         mutex_unlock(&dst_as->lock);
-
+        
         return 0;
 }
@@ -1195 +1195 @@
 {
         assert(mutex_locked(&area->lock));
-
+        
         int flagmap[] = {
                 [PF_ACCESS_READ] = AS_AREA_READ,
@@ -1201 +1201 @@
                 [PF_ACCESS_EXEC] = AS_AREA_EXEC
         };
-
+        
         if (!(area->flags & flagmap[access]))
                 return false;
-
+        
         return true;
 }
@@ -1218 +1218 @@
 {
         unsigned int flags = PAGE_USER | PAGE_PRESENT;
-
+        
         if (aflags & AS_AREA_READ)
                 flags |= PAGE_READ;
-
+                
         if (aflags & AS_AREA_WRITE)
                 flags |= PAGE_WRITE;
-
+        
         if (aflags & AS_AREA_EXEC)
                 flags |= PAGE_EXEC;
-
+        
         if (aflags & AS_AREA_CACHEABLE)
                 flags |= PAGE_CACHEABLE;
-
+        
         return flags;
 }
@@ -1252 +1252 @@
         /* Flags for the new memory mapping */
         unsigned int page_flags = area_flags_to_page_flags(flags);
-
+        
         mutex_lock(&as->lock);
-
+        
         as_area_t *area = find_area_and_lock(as, address);
         if (!area) {
@@ -1260 +1260 @@
                 return ENOENT;
         }
-
+        
         if (area->backend != &anon_backend) {
                 /* Copying non-anonymous memory not supported yet */
@@ -1277 +1277 @@
         }
         mutex_unlock(&area->sh_info->lock);
-
+        
         /*
          * Compute total number of used pages in the used_space B+tree
          */
         size_t used_pages = 0;
-
+        
         list_foreach(area->used_space.leaf_list, leaf_link, btree_node_t,
             node) {
                 btree_key_t i;
-
+                
                 for (i = 0; i < node->keys; i++)
                         used_pages += (size_t) node->value[i];
         }
-
+        
         /* An array for storing frame numbers */
         uintptr_t *old_frame = malloc(used_pages * sizeof(uintptr_t), 0);
-
+        
         page_table_lock(as, false);
-
+        
         /*
          * Start TLB shootdown sequence.
@@ -1301 +1301 @@
         ipl_t ipl = tlb_shootdown_start(TLB_INVL_PAGES, as->asid, area->base,
             area->pages);
-
+        
         /*
          * Remove used pages from page tables and remember their frame
@@ -1307 +1307 @@
          */
         size_t frame_idx = 0;
-
+        
         list_foreach(area->used_space.leaf_list, leaf_link, btree_node_t,
             node) {
                 btree_key_t i;
-
+                
                 for (i = 0; i < node->keys; i++) {
                         uintptr_t ptr = node->key[i];
                         size_t size;
-
+                        
                         for (size = 0; size < (size_t) node->value[i]; size++) {
                                 pte_t pte;
                                 bool found = page_mapping_find(as,
                                     ptr + P2SZ(size), false, &pte);
-
+                                
                                 assert(found);
                                 assert(PTE_VALID(&pte));
                                 assert(PTE_PRESENT(&pte));
-
+                                
                                 old_frame[frame_idx++] = PTE_GET_FRAME(&pte);
-
+                                
                                 /* Remove old mapping */
                                 page_mapping_remove(as, ptr + P2SZ(size));
@@ -1332 +1332 @@
                 }
         }
-
+        
         /*
          * Finish TLB shootdown sequence.
          */
-
+        
         tlb_invalidate_pages(as->asid, area->base, area->pages);
-
+        
         /*
          * Invalidate potential software translation caches
@@ -1345 +1345 @@
         as_invalidate_translation_cache(as, area->base, area->pages);
         tlb_shootdown_finalize(ipl);
-
+        
         page_table_unlock(as, false);
-
+        
         /*
          * Set the new flags.
          */
         area->flags = flags;
-
+        
         /*
          * Map pages back in with new flags. This step is kept separate
@@ -1359 +1359 @@
          */
         frame_idx = 0;
-
+        
         list_foreach(area->used_space.leaf_list, leaf_link, btree_node_t,
             node) {
                 btree_key_t i;
-
+                
                 for (i = 0; i < node->keys; i++) {
                         uintptr_t ptr = node->key[i];
                         size_t size;
-
+                        
                         for (size = 0; size < (size_t) node->value[i]; size++) {
                                 page_table_lock(as, false);
-
+                                
                                 /* Insert the new mapping */
                                 page_mapping_insert(as, ptr + P2SZ(size),
                                     old_frame[frame_idx++], page_flags);
-
+                                
                                 page_table_unlock(as, false);
                         }
                 }
         }
-
+        
         free(old_frame);
-
+        
         mutex_unlock(&area->lock);
         mutex_unlock(&as->lock);
-
+        
         return 0;
 }
@@ -1414 +1414 @@
         if (!THREAD)
                 goto page_fault;
-
+        
         if (!AS)
                 goto page_fault;
-
+        
         mutex_lock(&AS->lock);
         as_area_t *area = find_area_and_lock(AS, page);
@@ -1428 +1428 @@
                 goto page_fault;
         }
-
+        
         if (area->attributes & AS_AREA_ATTR_PARTIAL) {
                 /*
@@ -1438 +1438 @@
                 goto page_fault;
         }
-
+        
         if ((!area->backend) || (!area->backend->page_fault)) {
                 /*
@@ -1448 +1448 @@
                 goto page_fault;
         }
-
+        
         page_table_lock(AS, false);
-
+        
         /*
          * To avoid race condition between two page faults on the same address,
@@ -1467 +1467 @@
                 }
         }
-
+        
         /*
          * Resort to the backend page fault handler.
@@ -1478 +1478 @@
                 goto page_fault;
         }
-
+        
         page_table_unlock(AS, false);
         mutex_unlock(&area->lock);
         mutex_unlock(&AS->lock);
         return AS_PF_OK;
-
+        
 page_fault:
         if (THREAD->in_copy_from_uspace) {
@@ -1501 +1501 @@
                 panic_memtrap(istate, access, address, NULL);
         }
-
+        
         return AS_PF_DEFER;
 }
@@ -1521 +1521 @@
         DEADLOCK_PROBE_INIT(p_asidlock);
         preemption_disable();
-
+        
 retry:
         (void) interrupts_disable();
@@ -1536 +1536 @@
         }
         preemption_enable();
-
+        
         /*
          * First, take care of the old address space.
@@ -1542 +1542 @@
         if (old_as) {
                 assert(old_as->cpu_refcount);
-
+                
                 if ((--old_as->cpu_refcount == 0) && (old_as != AS_KERNEL)) {
                         /*
@@ -1551 +1551 @@
                          */
                         assert(old_as->asid != ASID_INVALID);
-
+                        
                         list_append(&old_as->inactive_as_with_asid_link,
                             &inactive_as_with_asid_list);
                 }
-
+                
                 /*
                  * Perform architecture-specific tasks when the address space
@@ -1562 +1562 @@
                 as_deinstall_arch(old_as);
         }
-
+        
         /*
          * Second, prepare the new address space.
@@ -1572 +1572 @@
                         new_as->asid = asid_get();
         }
-
+        
 #ifdef AS_PAGE_TABLE
         SET_PTL0_ADDRESS(new_as->genarch.page_table);
 #endif
-
+        
         /*
          * Perform architecture-specific steps.
@@ -1582 +1582 @@
          */
         as_install_arch(new_as);
-
+        
         spinlock_unlock(&asidlock);
-
+        
         AS = new_as;
 }
@@ -1598 +1598 @@
 {
         assert(mutex_locked(&area->lock));
-
+        
         return area_flags_to_page_flags(area->flags);
 }
@@ -1617 +1617 @@
         assert(as_operations);
         assert(as_operations->page_table_create);
-
+        
         return as_operations->page_table_create(flags);
 }
@@ -1632 +1632 @@
         assert(as_operations);
         assert(as_operations->page_table_destroy);
-
+        
         as_operations->page_table_destroy(page_table);
 }
@@ -1653 +1653 @@
         assert(as_operations);
         assert(as_operations->page_table_lock);
-
+        
         as_operations->page_table_lock(as, lock);
 }
@@ -1667 +1667 @@
         assert(as_operations);
         assert(as_operations->page_table_unlock);
-
+        
         as_operations->page_table_unlock(as, unlock);
 }
@@ -1697 +1697 @@
 {
         size_t size;
-
+        
         page_table_lock(AS, true);
         as_area_t *src_area = find_area_and_lock(AS, base);
-
+        
         if (src_area) {
                 size = P2SZ(src_area->pages);
@@ -1706 +1706 @@
         } else
                 size = 0;
-
+        
         page_table_unlock(AS, true);
         return size;
@@ -1727 +1727 @@
         assert(IS_ALIGNED(page, PAGE_SIZE));
         assert(count);
-
+        
         btree_node_t *leaf = NULL;
         size_t pages = (size_t) btree_search(&area->used_space, page, &leaf);
@@ -1738 +1738 @@
 
         assert(leaf != NULL);
-
+        
         if (!leaf->keys) {
                 btree_insert(&area->used_space, page, (void *) count, leaf);
                 goto success;
         }
-
+        
         btree_node_t *node = btree_leaf_node_left_neighbour(&area->used_space, leaf);
         if (node) {
@@ -1750 +1750 @@
                 size_t left_cnt = (size_t) node->value[node->keys - 1];
                 size_t right_cnt = (size_t) leaf->value[0];
-
+                
                 /*
                  * Examine the possibility that the interval fits
@@ -1756 +1756 @@
                  * the left neigbour and the first interval of the leaf.
                  */
-
+                
                 if (page >= right_pg) {
                         /* Do nothing. */
@@ -1804 +1804 @@
                 uintptr_t right_pg = leaf->key[0];
                 size_t right_cnt = (size_t) leaf->value[0];
-
+                
                 /*
                  * Investigate the border case in which the left neighbour does
                  * not exist but the interval fits from the left.
                  */
-
+                
                 if (overlaps(page, P2SZ(count), right_pg, P2SZ(right_cnt))) {
                         /* The interval intersects with the right interval. */
@@ -1832 +1832 @@
                 }
         }
-
+        
         node = btree_leaf_node_right_neighbour(&area->used_space, leaf);
         if (node) {
@@ -1839 +1839 @@
                 size_t left_cnt = (size_t) leaf->value[leaf->keys - 1];
                 size_t right_cnt = (size_t) node->value[0];
-
+                
                 /*
                  * Examine the possibility that the interval fits
@@ -1845 +1845 @@
                  * the right neigbour and the last interval of the leaf.
                  */
-
+                
                 if (page < left_pg) {
                         /* Do nothing. */
@@ -1893 +1893 @@
                 uintptr_t left_pg = leaf->key[leaf->keys - 1];
                 size_t left_cnt = (size_t) leaf->value[leaf->keys - 1];
-
+                
                 /*
                  * Investigate the border case in which the right neighbour
                  * does not exist but the interval fits from the right.
                  */
-
+                
                 if (overlaps(page, P2SZ(count), left_pg, P2SZ(left_cnt))) {
                         /* The interval intersects with the left interval. */
@@ -1919 +1919 @@
                 }
         }
-
+        
         /*
          * Note that if the algorithm made it thus far, the interval can fit
@@ -1932 +1932 @@
                         size_t left_cnt = (size_t) leaf->value[i - 1];
                         size_t right_cnt = (size_t) leaf->value[i];
-
+                        
                         /*
                          * The interval fits between left_pg and right_pg.
                          */
-
+                        
                         if (overlaps(page, P2SZ(count), left_pg,
                             P2SZ(left_cnt))) {
@@ -1988 +1988 @@
                 }
         }
-
+        
         panic("Inconsistency detected while adding %zu pages of used "
             "space at %p.", count, (void *) page);
-
+        
 success:
         area->resident += count;
@@ -2013 +2013 @@
         assert(IS_ALIGNED(page, PAGE_SIZE));
         assert(count);
-
+        
         btree_node_t *leaf;
         size_t pages = (size_t) btree_search(&area->used_space, page, &leaf);
@@ -2038 +2038 @@
                                 }
                         }
-
+                        
                         goto error;
                 }
         }
-
+        
         btree_node_t *node = btree_leaf_node_left_neighbour(&area->used_space,
             leaf);
@@ -2048 +2048 @@
                 uintptr_t left_pg = node->key[node->keys - 1];
                 size_t left_cnt = (size_t) node->value[node->keys - 1];
-
+                
                 if (overlaps(left_pg, P2SZ(left_cnt), page, P2SZ(count))) {
                         if (page + P2SZ(count) == left_pg + P2SZ(left_cnt)) {
@@ -2078 +2078 @@
                         }
                 }
-
+                
                 return false;
         } else if (page < leaf->key[0])
                 return false;
-
+        
         if (page > leaf->key[leaf->keys - 1]) {
                 uintptr_t left_pg = leaf->key[leaf->keys - 1];
                 size_t left_cnt = (size_t) leaf->value[leaf->keys - 1];
-
+                
                 if (overlaps(left_pg, P2SZ(left_cnt), page, P2SZ(count))) {
                         if (page + P2SZ(count) == left_pg + P2SZ(left_cnt)) {
@@ -2115 +2115 @@
                         }
                 }
-
+                
                 return false;
         }
-
+        
         /*
          * The border cases have been already resolved.
@@ -2128 +2128 @@
                         uintptr_t left_pg = leaf->key[i - 1];
                         size_t left_cnt = (size_t) leaf->value[i - 1];
-
+                        
                         /*
                          * Now the interval is between intervals corresponding
@@ -2166 +2166 @@
                                 }
                         }
-
+                        
                         return false;
                 }
         }
-
+        
 error:
         panic("Inconsistency detected while removing %zu pages of used "
             "space from %p.", count, (void *) page);
-
+        
 success:
         area->resident -= count;
@@ -2204 +2204 @@
         if (area == NULL)
                 return (sysarg_t) AS_MAP_FAILED;
-
+        
         return (sysarg_t) virt;
 }
@@ -2233 +2233 @@
 {
         mutex_lock(&as->lock);
-
+        
         /* First pass, count number of areas. */
-
+        
         size_t area_cnt = 0;
-
+        
         list_foreach(as->as_area_btree.leaf_list, leaf_link, btree_node_t,
             node) {
                 area_cnt += node->keys;
         }
-
+        
         size_t isize = area_cnt * sizeof(as_area_info_t);
         as_area_info_t *info = malloc(isize, 0);
-
+        
         /* Second pass, record data. */
-
+        
         size_t area_idx = 0;
-
+        
         list_foreach(as->as_area_btree.leaf_list, leaf_link, btree_node_t,
             node) {
                 btree_key_t i;
-
+                
                 for (i = 0; i < node->keys; i++) {
                         as_area_t *area = node->value[i];
-
+                        
                         assert(area_idx < area_cnt);
                         mutex_lock(&area->lock);
-
+                        
                         info[area_idx].start_addr = area->base;
                         info[area_idx].size = P2SZ(area->pages);
                         info[area_idx].flags = area->flags;
                         ++area_idx;
-
+                        
                         mutex_unlock(&area->lock);
                 }
         }
-
+        
         mutex_unlock(&as->lock);
-
+        
         *obuf = info;
         *osize = isize;
@@ -2283 +2283 @@
 {
         mutex_lock(&as->lock);
-
+        
         /* Print out info about address space areas */
         list_foreach(as->as_area_btree.leaf_list, leaf_link, btree_node_t,
             node) {
                 btree_key_t i;
-
+                
                 for (i = 0; i < node->keys; i++) {
                         as_area_t *area = node->value[i];
-
+                        
                         mutex_lock(&area->lock);
                         printf("as_area: %p, base=%p, pages=%zu"
@@ -2300 +2300 @@
                 }
         }
-
+        
         mutex_unlock(&as->lock);
 }