| 41,6 → 41,7 |
|---|
| #include <align.h> |
| #include <memstr.h> |
| #include <macros.h> |
| #include <arch.h> |
| |
| static char *error_codes[] = { |
| "no error", |
| 55,6 → 56,14 |
|---|
| static int section_header(elf_section_header_t *entry, elf_header_t *elf, as_t *as); |
| 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); |
| 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 |
| * |
| * @param header Pointer to ELF header in memory |
| 159,9 → 168,8 |
|---|
| int load_segment(elf_segment_header_t *entry, elf_header_t *elf, as_t *as) |
| { |
| as_area_t *a; |
| int i, flags = 0; |
| size_t segment_size; |
| __u8 *segment; |
| int flags = 0; |
| void *backend_data[2] = { elf, entry }; |
| |
| if (entry->p_align > 1) { |
| if ((entry->p_offset % entry->p_align) != (entry->p_vaddr % entry->p_align)) { |
| 182,23 → 190,14 |
|---|
| if (ALIGN_UP(entry->p_vaddr, PAGE_SIZE) != entry->p_vaddr) |
| return EE_UNSUPPORTED; |
| |
| segment_size = ALIGN_UP(max(entry->p_filesz, entry->p_memsz), PAGE_SIZE); |
| if ((entry->p_flags & PF_W)) { |
| /* If writable, copy data (should be COW in the future) */ |
| segment = malloc(segment_size, 0); |
| memsetb((__address) (segment + entry->p_filesz), segment_size - entry->p_filesz, 0); |
| memcpy(segment, (void *) (((__address) elf) + entry->p_offset), entry->p_filesz); |
| } else /* Map identically original data */ |
| segment = ((void *) elf) + entry->p_offset; |
| |
| a = as_area_create(as, flags, entry->p_memsz, entry->p_vaddr, AS_AREA_ATTR_NONE); |
| 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; |
| |
| for (i = 0; i < SIZE2FRAMES(entry->p_filesz); i++) { |
| as_set_mapping(as, entry->p_vaddr + i*PAGE_SIZE, KA2PA(((__address) segment) + i*PAGE_SIZE)); |
| } |
| |
| /* |
| * The segment will be mapped on demand by elf_page_fault(). |
| */ |
| |
| return EE_OK; |
| } |
| |
| 219,3 → 218,106 |
|---|
| |
| 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. |
| * |
| * @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) |
| { |
| 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; |
| |
| 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)); |
| } |
| } |