| 0,0 → 1,352 |
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| /* |
| * Copyright (c) 2006 Jakub Jermar |
| * All rights reserved. |
| * |
| * Redistribution and use in source and binary forms, with or without |
| * modification, are permitted provided that the following conditions |
| * are met: |
| * |
| * - Redistributions of source code must retain the above copyright |
| * notice, this list of conditions and the following disclaimer. |
| * - Redistributions in binary form must reproduce the above copyright |
| * notice, this list of conditions and the following disclaimer in the |
| * documentation and/or other materials provided with the distribution. |
| * - The name of the author may not be used to endorse or promote products |
| * derived from this software without specific prior written permission. |
| * |
| * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR |
| * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES |
| * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. |
| * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, |
| * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT |
| * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, |
| * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY |
| * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT |
| * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF |
| * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. |
| */ |
| |
| /** @addtogroup genericmm |
| * @{ |
| */ |
| |
| /** |
| * @file |
| * @brief Backend for address space areas backed by an ELF image. |
| */ |
| |
| #include <lib/elf.h> |
| #include <debug.h> |
| #include <arch/types.h> |
| #include <mm/as.h> |
| #include <mm/frame.h> |
| #include <mm/slab.h> |
| #include <mm/page.h> |
| #include <genarch/mm/page_pt.h> |
| #include <genarch/mm/page_ht.h> |
| #include <align.h> |
| #include <memstr.h> |
| #include <macros.h> |
| #include <arch.h> |
| #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); |
| |
| mem_backend_t elf_backend = { |
| .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; |
| elf_segment_header_t *entry = area->backend_data.segment; |
| btree_node_t *leaf; |
| uintptr_t base, frame, page, start_anon; |
| index_t i; |
| bool dirty = false; |
| |
| 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) { |
| 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("Could not insert used space.\n"); |
| 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("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, uintptr_t page, uintptr_t frame) |
| { |
| elf_header_t *elf = area->backend_data.elf; |
| elf_segment_header_t *entry = area->backend_data.segment; |
| uintptr_t base, start_anon; |
| index_t i; |
| |
| ASSERT((page >= ALIGN_DOWN(entry->p_vaddr, PAGE_SIZE)) && |
| (page < entry->p_vaddr + entry->p_memsz)); |
| i = (page - ALIGN_DOWN(entry->p_vaddr, PAGE_SIZE)) >> PAGE_WIDTH; |
| base = (uintptr_t) (((void *) elf) + |
| ALIGN_DOWN(entry->p_offset, FRAME_SIZE)); |
| 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); |
| } |
| } |
| |
| /** 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. |
| * |
| * The address space and address space area must be locked prior to the call. |
| * |
| * @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; |
| |
| /* |
| * 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]; |
| count_t count = (count_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); |
| } |
| |
| /** @} |
| */ |