Changes in kernel/generic/src/mm/backend_elf.c [8f80c77:8f6c6264] in mainline

File:

• kernel/generic/src/mm/backend_elf.c (modified) (3 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
 };
 
-/** Service a page fault in the ELF backend address space area.
- *
- * The address space area and page tables must be already locked.
- *
- * @param area          Pointer to the address space area.
- * @param addr          Faulting virtual address.
- * @param access        Access mode that caused the fault (i.e.
- *                      read/write/exec).
- *
- * @return              AS_PF_FAULT on failure (i.e. page fault) or AS_PF_OK
- *                      on success (i.e. serviced).
- */
-int elf_page_fault(as_area_t *area, uintptr_t addr, pf_access_t access)
-{
-        elf_header_t *elf = area->backend_data.elf;
+static size_t elf_nonanon_pages_get(as_area_t *area)
+{
         elf_segment_header_t *entry = area->backend_data.segment;
-        btree_node_t *leaf;
-        uintptr_t base, frame, page, start_anon;
-        size_t i;
-        bool dirty = false;
-
-        ASSERT(page_table_locked(AS));
-        ASSERT(mutex_locked(&area->lock));
-
-        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));
-        i = (addr - ALIGN_DOWN(entry->p_vaddr, PAGE_SIZE)) >> PAGE_WIDTH;
-        base = (uintptr_t)
-            (((void *) elf) + ALIGN_DOWN(entry->p_offset, PAGE_SIZE));
-
-        /* Virtual address of faulting page*/
-        page = ALIGN_DOWN(addr, PAGE_SIZE);
-
-        /* Virtual address of the end of initialized part of segment */
-        start_anon = entry->p_vaddr + entry->p_filesz;
-
-        if (area->sh_info) {
-                bool found = false;
-
-                /*
-                 * The address space area is shared.
-                 */
-                
-                mutex_lock(&area->sh_info->lock);
-                frame = (uintptr_t) btree_search(&area->sh_info->pagemap,
-                    page - area->base, &leaf);
-                if (!frame) {
-                        unsigned int i;
-
-                        /*
-                         * Workaround for valid NULL address.
-                         */
-
-                        for (i = 0; i < leaf->keys; i++) {
-                                if (leaf->key[i] == page - area->base) {
-                                        found = true;
-                                        break;
-                                }
-                        }
-                }
-                if (frame || found) {
-                        frame_reference_add(ADDR2PFN(frame));
-                        page_mapping_insert(AS, addr, frame,
-                            as_area_get_flags(area));
-                        if (!used_space_insert(area, page, 1))
-                                panic("Cannot insert used space.");
-                        mutex_unlock(&area->sh_info->lock);
-                        return AS_PF_OK;
-                }
-        }
-
-        /*
-         * The area is either not shared or the pagemap does not contain the
-         * mapping.
-         */
-        if (page >= entry->p_vaddr && page + PAGE_SIZE <= start_anon) {
-                /*
-                 * Initialized portion of the segment. The memory is backed
-                 * directly by the content of the ELF image. Pages are
-                 * only copied if the segment is writable so that there
-                 * can be more instantions of the same memory ELF image
-                 * used at a time. Note that this could be later done
-                 * as COW.
-                 */
-                if (entry->p_flags & PF_W) {
-                        frame = (uintptr_t)frame_alloc(ONE_FRAME, 0);
-                        memcpy((void *) PA2KA(frame),
-                            (void *) (base + i * FRAME_SIZE), FRAME_SIZE);
-                        if (entry->p_flags & PF_X) {
-                                smc_coherence_block((void *) PA2KA(frame),
-                                    FRAME_SIZE);
-                        }
-                        dirty = true;
-                } else {
-                        frame = KA2PA(base + i * FRAME_SIZE);
-                }       
-        } else if (page >= start_anon) {
-                /*
-                 * This is the uninitialized portion of the segment.
-                 * It is not physically present in the ELF image.
-                 * To resolve the situation, a frame must be allocated
-                 * and cleared.
-                 */
-                frame = (uintptr_t)frame_alloc(ONE_FRAME, 0);
-                memsetb((void *) PA2KA(frame), FRAME_SIZE, 0);
-                dirty = true;
-        } else {
-                size_t pad_lo, pad_hi;
-                /*
-                 * The mixed case.
-                 *
-                 * The middle part is backed by the ELF image and
-                 * the lower and upper parts are anonymous memory.
-                 * (The segment can be and often is shorter than 1 page).
-                 */
-                if (page < entry->p_vaddr)
-                        pad_lo = entry->p_vaddr - page;
-                else
-                        pad_lo = 0;
-
-                if (start_anon < page + PAGE_SIZE)
-                        pad_hi = page + PAGE_SIZE - start_anon;
-                else
-                        pad_hi = 0;
-
-                frame = (uintptr_t)frame_alloc(ONE_FRAME, 0);
-                memcpy((void *) (PA2KA(frame) + pad_lo),
-                    (void *) (base + i * FRAME_SIZE + pad_lo),
-                    FRAME_SIZE - pad_lo - pad_hi);
-                if (entry->p_flags & PF_X) {
-                        smc_coherence_block((void *) (PA2KA(frame) + pad_lo), 
-                            FRAME_SIZE - pad_lo - pad_hi);
-                }
-                memsetb((void *) PA2KA(frame), pad_lo, 0);
-                memsetb((void *) (PA2KA(frame) + FRAME_SIZE - pad_hi), pad_hi,
-                    0);
-                dirty = true;
-        }
-
-        if (dirty && area->sh_info) {
-                frame_reference_add(ADDR2PFN(frame));
-                btree_insert(&area->sh_info->pagemap, page - area->base,
-                    (void *) frame, leaf);
-        }
-
-        if (area->sh_info)
-                mutex_unlock(&area->sh_info->lock);
-
-        page_mapping_insert(AS, addr, frame, as_area_get_flags(area));
-        if (!used_space_insert(area, page, 1))
-                panic("Cannot insert used space.");
-
-        return AS_PF_OK;
-}
-
-/** Free a frame that is backed by the ELF backend.
- *
- * The address space area and page tables must be already locked.
- *
- * @param area          Pointer to the address space area.
- * @param page          Page that is mapped to frame. Must be aligned to
- *                      PAGE_SIZE.
- * @param frame         Frame to be released.
- *
- */
-void elf_frame_free(as_area_t *area, uintptr_t page, uintptr_t frame)
-{
-        elf_segment_header_t *entry = area->backend_data.segment;
-        uintptr_t start_anon;
-
-        ASSERT(page_table_locked(area->as));
-        ASSERT(mutex_locked(&area->lock));
-
-        ASSERT(page >= ALIGN_DOWN(entry->p_vaddr, PAGE_SIZE));
-        ASSERT(page < entry->p_vaddr + entry->p_memsz);
-
-        start_anon = entry->p_vaddr + entry->p_filesz;
-
-        if (page >= entry->p_vaddr && page + PAGE_SIZE <= start_anon) {
-                if (entry->p_flags & PF_W) {
-                        /*
-                         * Free the frame with the copy of writable segment
-                         * data.
-                         */
-                        frame_free(frame);
-                }
-        } else {
-                /*
-                 * The frame is either anonymous memory or the mixed case (i.e.
-                 * lower part is backed by the ELF image and the upper is
-                 * anonymous). In any case, a frame needs to be freed.
-                 */
-                frame_free(frame);
-        }
+        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;
 }
 
@@ -352 +205 @@
 }
 
+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.
+ *
+ * The address space area and page tables must be already locked.
+ *
+ * @param area          Pointer to the address space area.
+ * @param addr          Faulting virtual address.
+ * @param access        Access mode that caused the fault (i.e.
+ *                      read/write/exec).
+ *
+ * @return              AS_PF_FAULT on failure (i.e. page fault) or AS_PF_OK
+ *                      on success (i.e. serviced).
+ */
+int elf_page_fault(as_area_t *area, uintptr_t addr, pf_access_t access)
+{
+        elf_header_t *elf = area->backend_data.elf;
+        elf_segment_header_t *entry = area->backend_data.segment;
+        btree_node_t *leaf;
+        uintptr_t base, frame, page, start_anon;
+        size_t i;
+        bool dirty = false;
+
+        ASSERT(page_table_locked(AS));
+        ASSERT(mutex_locked(&area->lock));
+
+        if (!as_area_check_access(area, access))
+                return AS_PF_FAULT;
+        
+        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)
+            (((void *) elf) + ALIGN_DOWN(entry->p_offset, PAGE_SIZE));
+
+        /* Virtual address of faulting page*/
+        page = ALIGN_DOWN(addr, PAGE_SIZE);
+
+        /* Virtual address of the end of initialized part of segment */
+        start_anon = entry->p_vaddr + entry->p_filesz;
+
+        if (area->sh_info) {
+                bool found = false;
+
+                /*
+                 * The address space area is shared.
+                 */
+                
+                mutex_lock(&area->sh_info->lock);
+                frame = (uintptr_t) btree_search(&area->sh_info->pagemap,
+                    page - area->base, &leaf);
+                if (!frame) {
+                        unsigned int i;
+
+                        /*
+                         * Workaround for valid NULL address.
+                         */
+
+                        for (i = 0; i < leaf->keys; i++) {
+                                if (leaf->key[i] == page - area->base) {
+                                        found = true;
+                                        break;
+                                }
+                        }
+                }
+                if (frame || found) {
+                        frame_reference_add(ADDR2PFN(frame));
+                        page_mapping_insert(AS, addr, frame,
+                            as_area_get_flags(area));
+                        if (!used_space_insert(area, page, 1))
+                                panic("Cannot insert used space.");
+                        mutex_unlock(&area->sh_info->lock);
+                        return AS_PF_OK;
+                }
+        }
+
+        /*
+         * The area is either not shared or the pagemap does not contain the
+         * mapping.
+         */
+        if (page >= entry->p_vaddr && page + PAGE_SIZE <= start_anon) {
+                /*
+                 * Initialized portion of the segment. The memory is backed
+                 * directly by the content of the ELF image. Pages are
+                 * only copied if the segment is writable so that there
+                 * can be more instantions of the same memory ELF image
+                 * used at a time. Note that this could be later done
+                 * as COW.
+                 */
+                if (entry->p_flags & PF_W) {
+                        frame = (uintptr_t)frame_alloc_noreserve(ONE_FRAME, 0);
+                        memcpy((void *) PA2KA(frame),
+                            (void *) (base + i * FRAME_SIZE), FRAME_SIZE);
+                        if (entry->p_flags & PF_X) {
+                                smc_coherence_block((void *) PA2KA(frame),
+                                    FRAME_SIZE);
+                        }
+                        dirty = true;
+                } else {
+                        frame = KA2PA(base + i * FRAME_SIZE);
+                }       
+        } else if (page >= start_anon) {
+                /*
+                 * This is the uninitialized portion of the segment.
+                 * It is not physically present in the ELF image.
+                 * To resolve the situation, a frame must be allocated
+                 * and cleared.
+                 */
+                frame = (uintptr_t) frame_alloc_noreserve(ONE_FRAME, 0);
+                memsetb((void *) PA2KA(frame), FRAME_SIZE, 0);
+                dirty = true;
+        } else {
+                size_t pad_lo, pad_hi;
+                /*
+                 * The mixed case.
+                 *
+                 * The middle part is backed by the ELF image and
+                 * the lower and upper parts are anonymous memory.
+                 * (The segment can be and often is shorter than 1 page).
+                 */
+                if (page < entry->p_vaddr)
+                        pad_lo = entry->p_vaddr - page;
+                else
+                        pad_lo = 0;
+
+                if (start_anon < page + PAGE_SIZE)
+                        pad_hi = page + PAGE_SIZE - start_anon;
+                else
+                        pad_hi = 0;
+
+                frame = (uintptr_t) frame_alloc_noreserve(ONE_FRAME, 0);
+                memcpy((void *) (PA2KA(frame) + pad_lo),
+                    (void *) (base + i * FRAME_SIZE + pad_lo),
+                    FRAME_SIZE - pad_lo - pad_hi);
+                if (entry->p_flags & PF_X) {
+                        smc_coherence_block((void *) (PA2KA(frame) + pad_lo), 
+                            FRAME_SIZE - pad_lo - pad_hi);
+                }
+                memsetb((void *) PA2KA(frame), pad_lo, 0);
+                memsetb((void *) (PA2KA(frame) + FRAME_SIZE - pad_hi), pad_hi,
+                    0);
+                dirty = true;
+        }
+
+        if (dirty && area->sh_info) {
+                frame_reference_add(ADDR2PFN(frame));
+                btree_insert(&area->sh_info->pagemap, page - area->base,
+                    (void *) frame, leaf);
+        }
+
+        if (area->sh_info)
+                mutex_unlock(&area->sh_info->lock);
+
+        page_mapping_insert(AS, addr, frame, as_area_get_flags(area));
+        if (!used_space_insert(area, page, 1))
+                panic("Cannot insert used space.");
+
+        return AS_PF_OK;
+}
+
+/** Free a frame that is backed by the ELF backend.
+ *
+ * The address space area and page tables must be already locked.
+ *
+ * @param area          Pointer to the address space area.
+ * @param page          Page that is mapped to frame. Must be aligned to
+ *                      PAGE_SIZE.
+ * @param frame         Frame to be released.
+ *
+ */
+void elf_frame_free(as_area_t *area, uintptr_t page, uintptr_t frame)
+{
+        elf_segment_header_t *entry = area->backend_data.segment;
+        uintptr_t start_anon;
+
+        ASSERT(page_table_locked(area->as));
+        ASSERT(mutex_locked(&area->lock));
+
+        ASSERT(page >= ALIGN_DOWN(entry->p_vaddr, PAGE_SIZE));
+        ASSERT(page < entry->p_vaddr + entry->p_memsz);
+
+        start_anon = entry->p_vaddr + entry->p_filesz;
+
+        if (page >= entry->p_vaddr && page + PAGE_SIZE <= start_anon) {
+                if (entry->p_flags & PF_W) {
+                        /*
+                         * Free the frame with the copy of writable segment
+                         * data.
+                         */
+                        frame_free_noreserve(frame);
+                }
+        } else {
+                /*
+                 * The frame is either anonymous memory or the mixed case (i.e.
+                 * lower part is backed by the ELF image and the upper is
+                 * anonymous). In any case, a frame needs to be freed.
+                 */
+                frame_free_noreserve(frame);
+        }
+}
+
 /** @}
  */