Changeset 0ee077ee in mainline for generic/src/lib/elf.c

Timestamp:

2006-05-27T17:50:30Z (19 years ago)

Author:

Jakub Jermar <jakub@…>

Branches:

lfn, master, serial, ticket/834-toolchain-update, topic/msim-upgrade, topic/simplify-dev-export

Children:

127c957b

Parents:

fb84455

Message:

Move the sharing functionality to address space area backends.
Add backend for continuous regions of physical memory.
Sharing for these areas works automagically now.

File:

• generic/src/lib/elf.c (modified) (6 diffs)

generic/src/lib/elf.c

@@ -1 +1 @@
 /*
  * Copyright (C) 2006 Sergey Bondari
+ * Copyright (C) 2006 Jakub Jermar
  * All rights reserved.
  *
@@ -57 +58 @@
 static int load_segment(elf_segment_header_t *entry, elf_header_t *elf, as_t *as);
 
-static int elf_page_fault(as_area_t *area, __address addr, pf_access_t access);
-static void elf_frame_free(as_area_t *area, __address page, __address frame);
-
-mem_backend_t elf_backend = {
-        .backend_page_fault = elf_page_fault,
-        .backend_frame_free = elf_frame_free
-};
-
 /** ELF loader
  *
@@ -170 +163 @@
         as_area_t *a;
         int flags = 0;
-        void *backend_data[2] = { elf, entry };
+        mem_backend_data_t backend_data = { .d1 = (__native) elf, .d2 = (__native) entry };
 
         if (entry->p_align > 1) {
@@ -184 +177 @@
         if (entry->p_flags & PF_R)
                 flags |= AS_AREA_READ;
+        flags |= AS_AREA_CACHEABLE;
 
         /*
@@ -191 +185 @@
                 return EE_UNSUPPORTED;
 
-        a = as_area_create(as, flags, entry->p_memsz, entry->p_vaddr, AS_AREA_ATTR_NONE, &elf_backend, backend_data);
+        a = as_area_create(as, flags, entry->p_memsz, entry->p_vaddr, AS_AREA_ATTR_NONE,
+                &elf_backend, &backend_data);
         if (!a)
                 return EE_MEMORY;
@@ -219 +214 @@
         return EE_OK;
 }
-
-/** 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, __address addr, pf_access_t access)
-{
-        elf_header_t *elf = (elf_header_t *) area->backend_data[0];
-        elf_segment_header_t *entry = (elf_segment_header_t *) area->backend_data[1];
-        __address base, frame;
-        index_t i;
-
-        if (!as_area_check_access(area, access))
-                return AS_PF_FAULT;
-
-        ASSERT((addr >= entry->p_vaddr) && (addr < entry->p_vaddr + entry->p_memsz));
-        i = (addr - entry->p_vaddr) >> PAGE_WIDTH;
-        base = (__address) (((void *) elf) + entry->p_offset);
-        ASSERT(ALIGN_UP(base, FRAME_SIZE) == base);
-        
-        if (ALIGN_DOWN(addr, PAGE_SIZE) + PAGE_SIZE < entry->p_vaddr + entry->p_filesz) {
-                /*
-                 * 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 = PFN2ADDR(frame_alloc(ONE_FRAME, 0));
-                        memcpy((void *) PA2KA(frame), (void *) (base + i*FRAME_SIZE), FRAME_SIZE);
-                } else {
-                        frame = KA2PA(base + i*FRAME_SIZE);
-                }       
-        } else if (ALIGN_DOWN(addr, PAGE_SIZE) >= ALIGN_UP(entry->p_vaddr + entry->p_filesz, PAGE_SIZE)) {
-                /*
-                 * 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 = PFN2ADDR(frame_alloc(ONE_FRAME, 0));
-                memsetb(PA2KA(frame), FRAME_SIZE, 0);
-        } else {
-                size_t size;
-                /*
-                 * The mixed case.
-                 * The lower part is backed by the ELF image and
-                 * the upper part is anonymous memory.
-                 */
-                size = entry->p_filesz - (i<<PAGE_WIDTH);
-                frame = PFN2ADDR(frame_alloc(ONE_FRAME, 0));
-                memsetb(PA2KA(frame) + size, FRAME_SIZE - size, 0);
-                memcpy((void *) PA2KA(frame), (void *) (base + i*FRAME_SIZE), size);
-        }
-        
-        page_mapping_insert(AS, addr, frame, as_area_get_flags(area));
-        if (!used_space_insert(area, ALIGN_DOWN(addr, PAGE_SIZE), 1))
-                panic("Could not insert used space.\n");
-
-        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, __address page, __address frame)
-{
-        elf_header_t *elf = (elf_header_t *) area->backend_data[0];
-        elf_segment_header_t *entry = (elf_segment_header_t *) area->backend_data[1];
-        __address base;
-        index_t i;
-        
-        ASSERT((page >= entry->p_vaddr) && (page < entry->p_vaddr + entry->p_memsz));
-        i = (page - entry->p_vaddr) >> PAGE_WIDTH;
-        base = (__address) (((void *) elf) + entry->p_offset);
-        ASSERT(ALIGN_UP(base, FRAME_SIZE) == base);
-        
-        if (page + PAGE_SIZE < ALIGN_UP(entry->p_vaddr + entry->p_filesz, PAGE_SIZE)) {
-                if (entry->p_flags & PF_W) {
-                        /*
-                         * Free the frame with the copy of writable segment data.
-                         */
-                        frame_free(ADDR2PFN(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(ADDR2PFN(frame)); 
-        }
-}