Changes in kernel/generic/src/mm/backend_elf.c [8f80c77:55b77d9] in mainline

File:

• kernel/generic/src/mm/backend_elf.c (modified) (8 diffs)

kernel/generic/src/mm/backend_elf.c

@@ -43 +43 @@
 #include <mm/slab.h>
 #include <mm/page.h>
+#include <mm/reserve.h>
 #include <genarch/mm/page_pt.h>
 #include <genarch/mm/page_ht.h>
@@ -51 +52 @@
 #include <arch/barrier.h>
 
-#ifdef CONFIG_VIRT_IDX_DCACHE
-#include <arch/mm/cache.h>
-#endif
-
-static int elf_page_fault(as_area_t *area, uintptr_t addr, pf_access_t access);
-static void elf_frame_free(as_area_t *area, uintptr_t page, uintptr_t frame);
-static void elf_share(as_area_t *area);
+static bool elf_create(as_area_t *);
+static bool elf_resize(as_area_t *, size_t);
+static void elf_share(as_area_t *);
+static void elf_destroy(as_area_t *);
+
+static int elf_page_fault(as_area_t *, uintptr_t, pf_access_t);
+static void elf_frame_free(as_area_t *, uintptr_t, uintptr_t);
 
 mem_backend_t elf_backend = {
+        .create = elf_create,
+        .resize = elf_resize,
+        .share = elf_share,
+        .destroy = elf_destroy,
+
         .page_fault = elf_page_fault,
         .frame_free = elf_frame_free,
-        .share = elf_share
 };
+
+static size_t elf_nonanon_pages_get(as_area_t *area)
+{
+        elf_segment_header_t *entry = area->backend_data.segment;
+        uintptr_t first = ALIGN_UP(entry->p_vaddr, PAGE_SIZE);
+        uintptr_t last = ALIGN_DOWN(entry->p_vaddr + entry->p_filesz,
+            PAGE_SIZE);
+
+        if (entry->p_flags & PF_W)
+                return 0;
+
+        if (last < first)
+                return 0;
+
+        return last - first;
+}
+
+bool elf_create(as_area_t *area)
+{
+        size_t nonanon_pages = elf_nonanon_pages_get(area);
+
+        if (area->pages <= nonanon_pages)
+                return true;
+        
+        return reserve_try_alloc(area->pages - nonanon_pages);
+}
+
+bool elf_resize(as_area_t *area, size_t new_pages)
+{
+        size_t nonanon_pages = elf_nonanon_pages_get(area);
+
+        if (new_pages > area->pages) {
+                /* The area is growing. */
+                if (area->pages >= nonanon_pages)
+                        return reserve_try_alloc(new_pages - area->pages);
+                else if (new_pages > nonanon_pages)
+                        return reserve_try_alloc(new_pages - nonanon_pages);
+        } else if (new_pages < area->pages) {
+                /* The area is shrinking. */
+                if (new_pages >= nonanon_pages)
+                        reserve_free(area->pages - new_pages);
+                else if (area->pages > nonanon_pages)
+                        reserve_free(nonanon_pages - new_pages);
+        }
+        
+        return true;
+}
+
+/** Share ELF image backed address space area.
+ *
+ * If the area is writable, then all mapped pages are duplicated in the pagemap.
+ * Otherwise only portions of the area that are not backed by the ELF image
+ * are put into the pagemap.
+ *
+ * @param area          Address space area.
+ */
+void elf_share(as_area_t *area)
+{
+        elf_segment_header_t *entry = area->backend_data.segment;
+        link_t *cur;
+        btree_node_t *leaf, *node;
+        uintptr_t start_anon = entry->p_vaddr + entry->p_filesz;
+
+        ASSERT(mutex_locked(&area->as->lock));
+        ASSERT(mutex_locked(&area->lock));
+
+        /*
+         * Find the node in which to start linear search.
+         */
+        if (area->flags & AS_AREA_WRITE) {
+                node = list_get_instance(list_first(&area->used_space.leaf_list),
+                    btree_node_t, leaf_link);
+        } else {
+                (void) btree_search(&area->sh_info->pagemap, start_anon, &leaf);
+                node = btree_leaf_node_left_neighbour(&area->sh_info->pagemap,
+                    leaf);
+                if (!node)
+                        node = leaf;
+        }
+
+        /*
+         * Copy used anonymous portions of the area to sh_info's page map.
+         */
+        mutex_lock(&area->sh_info->lock);
+        for (cur = &node->leaf_link; cur != &area->used_space.leaf_list.head;
+            cur = cur->next) {
+                unsigned int i;
+                
+                node = list_get_instance(cur, btree_node_t, leaf_link);
+                
+                for (i = 0; i < node->keys; i++) {
+                        uintptr_t base = node->key[i];
+                        size_t count = (size_t) node->value[i];
+                        unsigned int j;
+                        
+                        /*
+                         * Skip read-only areas of used space that are backed
+                         * by the ELF image.
+                         */
+                        if (!(area->flags & AS_AREA_WRITE))
+                                if (base >= entry->p_vaddr &&
+                                    base + P2SZ(count) <= start_anon)
+                                        continue;
+                        
+                        for (j = 0; j < count; j++) {
+                                pte_t *pte;
+                        
+                                /*
+                                 * Skip read-only pages that are backed by the
+                                 * ELF image.
+                                 */
+                                if (!(area->flags & AS_AREA_WRITE))
+                                        if (base >= entry->p_vaddr &&
+                                            base + P2SZ(j + 1) <= start_anon)
+                                                continue;
+                                
+                                page_table_lock(area->as, false);
+                                pte = page_mapping_find(area->as,
+                                    base + P2SZ(j), false);
+                                ASSERT(pte && PTE_VALID(pte) &&
+                                    PTE_PRESENT(pte));
+                                btree_insert(&area->sh_info->pagemap,
+                                    (base + P2SZ(j)) - area->base,
+                                    (void *) PTE_GET_FRAME(pte), NULL);
+                                page_table_unlock(area->as, false);
+
+                                pfn_t pfn = ADDR2PFN(PTE_GET_FRAME(pte));
+                                frame_reference_add(pfn);
+                        }
+                                
+                }
+        }
+        mutex_unlock(&area->sh_info->lock);
+}
+
+void elf_destroy(as_area_t *area)
+{
+        size_t nonanon_pages = elf_nonanon_pages_get(area);
+
+        if (area->pages > nonanon_pages)
+                reserve_free(area->pages - nonanon_pages);
+}
 
 /** Service a page fault in the ELF backend address space area.
@@ -91 +238 @@
         if (!as_area_check_access(area, access))
                 return AS_PF_FAULT;
-
-        ASSERT((addr >= ALIGN_DOWN(entry->p_vaddr, PAGE_SIZE)) &&
-            (addr < entry->p_vaddr + entry->p_memsz));
+        
+        if (addr < ALIGN_DOWN(entry->p_vaddr, PAGE_SIZE))
+                return AS_PF_FAULT;
+        
+        if (addr >= entry->p_vaddr + entry->p_memsz)
+                return AS_PF_FAULT;
+        
         i = (addr - ALIGN_DOWN(entry->p_vaddr, PAGE_SIZE)) >> PAGE_WIDTH;
         base = (uintptr_t)
@@ -153 +304 @@
                  */
                 if (entry->p_flags & PF_W) {
-                        frame = (uintptr_t)frame_alloc(ONE_FRAME, 0);
+                        frame = (uintptr_t)frame_alloc_noreserve(ONE_FRAME, 0);
                         memcpy((void *) PA2KA(frame),
                             (void *) (base + i * FRAME_SIZE), FRAME_SIZE);
@@ -171 +322 @@
                  * and cleared.
                  */
-                frame = (uintptr_t)frame_alloc(ONE_FRAME, 0);
+                frame = (uintptr_t) frame_alloc_noreserve(ONE_FRAME, 0);
                 memsetb((void *) PA2KA(frame), FRAME_SIZE, 0);
                 dirty = true;
@@ -193 +344 @@
                         pad_hi = 0;
 
-                frame = (uintptr_t)frame_alloc(ONE_FRAME, 0);
+                frame = (uintptr_t) frame_alloc_noreserve(ONE_FRAME, 0);
                 memcpy((void *) (PA2KA(frame) + pad_lo),
                     (void *) (base + i * FRAME_SIZE + pad_lo),
@@ -252 +403 @@
                          * data.
                          */
-                        frame_free(frame);
+                        frame_free_noreserve(frame);
                 }
         } else {
@@ -260 +411 @@
                  * anonymous). In any case, a frame needs to be freed.
                  */
-                frame_free(frame);
-        }
-}
-
-/** Share ELF image backed address space area.
- *
- * If the area is writable, then all mapped pages are duplicated in the pagemap.
- * Otherwise only portions of the area that are not backed by the ELF image
- * are put into the pagemap.
- *
- * @param area          Address space area.
- */
-void elf_share(as_area_t *area)
-{
-        elf_segment_header_t *entry = area->backend_data.segment;
-        link_t *cur;
-        btree_node_t *leaf, *node;
-        uintptr_t start_anon = entry->p_vaddr + entry->p_filesz;
-
-        ASSERT(mutex_locked(&area->as->lock));
-        ASSERT(mutex_locked(&area->lock));
-
-        /*
-         * Find the node in which to start linear search.
-         */
-        if (area->flags & AS_AREA_WRITE) {
-                node = list_get_instance(area->used_space.leaf_head.next,
-                    btree_node_t, leaf_link);
-        } else {
-                (void) btree_search(&area->sh_info->pagemap, start_anon, &leaf);
-                node = btree_leaf_node_left_neighbour(&area->sh_info->pagemap,
-                    leaf);
-                if (!node)
-                        node = leaf;
-        }
-
-        /*
-         * Copy used anonymous portions of the area to sh_info's page map.
-         */
-        mutex_lock(&area->sh_info->lock);
-        for (cur = &node->leaf_link; cur != &area->used_space.leaf_head;
-            cur = cur->next) {
-                unsigned int i;
-                
-                node = list_get_instance(cur, btree_node_t, leaf_link);
-                
-                for (i = 0; i < node->keys; i++) {
-                        uintptr_t base = node->key[i];
-                        size_t count = (size_t) node->value[i];
-                        unsigned int j;
-                        
-                        /*
-                         * Skip read-only areas of used space that are backed
-                         * by the ELF image.
-                         */
-                        if (!(area->flags & AS_AREA_WRITE))
-                                if (base >= entry->p_vaddr &&
-                                    base + count * PAGE_SIZE <= start_anon)
-                                        continue;
-                        
-                        for (j = 0; j < count; j++) {
-                                pte_t *pte;
-                        
-                                /*
-                                 * Skip read-only pages that are backed by the
-                                 * ELF image.
-                                 */
-                                if (!(area->flags & AS_AREA_WRITE))
-                                        if (base >= entry->p_vaddr &&
-                                            base + (j + 1) * PAGE_SIZE <=
-                                            start_anon)
-                                                continue;
-                                
-                                page_table_lock(area->as, false);
-                                pte = page_mapping_find(area->as,
-                                    base + j * PAGE_SIZE);
-                                ASSERT(pte && PTE_VALID(pte) &&
-                                    PTE_PRESENT(pte));
-                                btree_insert(&area->sh_info->pagemap,
-                                    (base + j * PAGE_SIZE) - area->base,
-                                    (void *) PTE_GET_FRAME(pte), NULL);
-                                page_table_unlock(area->as, false);
-
-                                pfn_t pfn = ADDR2PFN(PTE_GET_FRAME(pte));
-                                frame_reference_add(pfn);
-                        }
-                                
-                }
-        }
-        mutex_unlock(&area->sh_info->lock);
+                frame_free_noreserve(frame);
+        }
 }