diff options
Diffstat (limited to 'kernel/vm/vmmap.c')
| -rw-r--r-- | kernel/vm/vmmap.c | 225 |
1 files changed, 116 insertions, 109 deletions
diff --git a/kernel/vm/vmmap.c b/kernel/vm/vmmap.c index 8789371..8c1a455 100644 --- a/kernel/vm/vmmap.c +++ b/kernel/vm/vmmap.c @@ -49,7 +49,7 @@ vmarea_t *vmarea_alloc(void) new_vmarea->vma_prot = 0; new_vmarea->vma_flags = 0; new_vmarea->vma_obj = NULL; - new_vmarea->vma_obj = NULL; + new_vmarea->vma_vmmap = NULL; list_link_init(&new_vmarea->vma_plink); // Return the new vmarea @@ -134,6 +134,8 @@ void vmmap_insert(vmmap_t *map, vmarea_t *new_vma) { // NOT_YET_IMPLEMENTED("VM: vmmap_insert*"); + new_vma->vma_vmmap = map; + // iterate over the list of vmareas list_iterate(&map->vmm_list, vma, vmarea_t, vma_plink) { @@ -173,47 +175,48 @@ ssize_t vmmap_find_range(vmmap_t *map, size_t npages, int dir) if (dir == VMMAP_DIR_LOHI) { // iterate over the page numbers, going from low to high - // determine the continguous range of free virtual pages + // determine the continguous range of free virtual pages - int start, end = 0; + size_t start_page, contig_page = 0; size_t vfn = ADDR_TO_PN(USER_MEM_LOW); - while (vfn <= ADDR_TO_PN(USER_MEM_HIGH)) + while (vfn++ < ADDR_TO_PN(USER_MEM_HIGH)) { // Lookup the vmarea for this page number - vmarea_t *vma = vmmap_lookup(map, vfn++); + vmarea_t *vma = vmmap_lookup(map, vfn); if (vma == NULL) { // if unmapped, document this - end = vfn; - if (start == 0) + if (contig_page == 0) { - start = vfn; + start_page = 0; } + contig_page++; } else { // if mapped, start over - start, end = 0; + start_page = contig_page = 0; } // if the range exists, return the start - if (end == npages) + if (contig_page == npages) { - return start; + KASSERT(start_page >= ADDR_TO_PN(USER_MEM_LOW)); + return start_page; } } } - + // case 2: dir is VMMAP_DIR_HILO - else if (dir == VMMAP_DIR_HILO) + if (dir == VMMAP_DIR_HILO) { // iterate over the page numbers - int contig = 0; + size_t contig = 0; size_t vfn = ADDR_TO_PN(USER_MEM_HIGH); - while (vfn >= ADDR_TO_PN(USER_MEM_LOW)) + while (--vfn >= ADDR_TO_PN(USER_MEM_LOW)) { // Lookup the vmarea for this page number - vmarea_t *vma = vmmap_lookup(map, --vfn); + vmarea_t *vma = vmmap_lookup(map, vfn); if (vma == NULL) { // if unmapped, increment the contig @@ -228,6 +231,7 @@ ssize_t vmmap_find_range(vmmap_t *map, size_t npages, int dir) // if there are n contiguous pages, return the current vfn if (contig == npages) { + KASSERT(vfn >= ADDR_TO_PN(USER_MEM_LOW)); return vfn; } } @@ -298,6 +302,7 @@ vmmap_t *vmmap_clone(vmmap_t *map) // NOT_YET_IMPLEMENTED("VM: vmmap_clone"); // Create a new vmmap + // vmmap_collapse(map); vmmap_t *new_vmmap = vmmap_create(); if (new_vmmap == NULL) { @@ -413,97 +418,101 @@ long vmmap_map(vmmap_t *map, vnode_t *file, size_t lopage, size_t npages, int prot, int flags, off_t off, int dir, vmarea_t **new_vma) { // NOT_YET_IMPLEMENTED("VM: vmmap_map"); + // return -1; + + // ASK: why are these needed!! + KASSERT(map != NULL); + KASSERT(prot == PROT_NONE + || prot == PROT_READ + || prot == PROT_WRITE + || prot == PROT_EXEC + || prot == (PROT_READ | PROT_WRITE) + || prot == (PROT_READ | PROT_EXEC) + || prot == (PROT_WRITE | PROT_EXEC) + || prot == (PROT_READ | PROT_WRITE | PROT_EXEC)); + KASSERT((flags & MAP_TYPE) == MAP_SHARED || (flags & MAP_TYPE) == MAP_PRIVATE); + + if (lopage == 0) + { + KASSERT(dir == VMMAP_DIR_LOHI || dir == VMMAP_DIR_HILO); + ssize_t res = vmmap_find_range(map, npages, dir); + if (res == -1) { + return -ENOMEM; + } + lopage = res; + } - // Create a new vmarea - // see if lopage is 0. if so, use vmmap_find_range() to get a valid range - if (lopage == 0) + if (lopage != 0 && (flags & MAP_FIXED)) { - lopage = vmmap_find_range(map, npages, dir); - if (lopage == -1) + long ret = vmmap_remove(map, lopage, npages); + if (ret < 0) { - return -ENOMEM; + return ret; } } - // Alloc the new vmarea - vmarea_t *new_vmarea = vmarea_alloc(); - if (new_vmarea == NULL) + // alloc the new vma + vmarea_t *vma = vmarea_alloc(); + if (!vma) { return -ENOMEM; } - // Set the fields of the new vmarea - new_vmarea->vma_start = lopage; - new_vmarea->vma_end = lopage + npages; - new_vmarea->vma_off = ADDR_TO_PN(off); - new_vmarea->vma_prot = prot; - new_vmarea->vma_flags = flags; - new_vmarea->vma_vmmap = map; - new_vmarea->vma_obj = NULL; - // If file is NULL, create an anon object - if (file == NULL) + // fill in fields, except for mobj and vma + vma->vma_start = lopage; + vma->vma_end = lopage + npages; + vma->vma_off = ADDR_TO_PN(off); + vma->vma_prot = prot; + vma->vma_flags = flags; + + // make the mobj, depending on the case (anon or mmap) + mobj_t *obj = NULL; + if (file == NULL) { - new_vmarea->vma_obj = anon_create(); - mobj_unlock(new_vmarea->vma_obj); // unlock the anon object before use - if (new_vmarea->vma_obj == NULL) + obj = anon_create(); + if (obj == NULL) { - vmarea_free(new_vmarea); + vmarea_free(vma); return -ENOMEM; } - } + mobj_unlock(obj); + } else { - // If file is non-NULL, use the vnode's mmap operation to get the mobj - long ret = file->vn_ops->mmap(file, &new_vmarea->vma_obj); + long ret = file->vn_ops->mmap(file, &obj); if (ret < 0) { - // on fail, free the new vmarea and return the error - vmarea_free(new_vmarea); + vmarea_free(vma); return ret; } } + vma->vma_obj = obj; - // If MAP_PRIVATE is specified, set up a shadow object - if (flags & MAP_PRIVATE) + // if the flag is private, upgrade the obj to a shadow obj + if (flags & MAP_PRIVATE) { - mobj_lock(new_vmarea->vma_obj); - mobj_t *shadow_obj = shadow_create(new_vmarea->vma_obj); - mobj_unlock(new_vmarea->vma_obj); - mobj_unlock(shadow_obj); // unlock the shadow object before use - mobj_put(&new_vmarea->vma_obj); // put the original object - if (shadow_obj == NULL) + mobj_t *shadow_obj = shadow_create(obj); + if (shadow_obj == NULL) { - vmarea_free(new_vmarea); + vmarea_free(vma); + mobj_put(&obj); return -ENOMEM; } - new_vmarea->vma_obj = shadow_obj; - } + // unlock from creation + mobj_unlock(shadow_obj); - // If MAP_FIXED is specified and the given range overlaps with any preexisting mappings, remove the preexisting mappings - if (lopage != 0 && (flags & MAP_FIXED)) - { - long ret = vmmap_remove(map, lopage, npages); - if (ret < 0) - { - vmarea_free(new_vmarea); - // remove/put the shadow/annon object if it exists - if (new_vmarea->vma_obj) - { - mobj_put(&new_vmarea->vma_obj); // FIXME: is this correct! - } - - return ret; - } + vma->vma_obj = shadow_obj; + // put the og obj + mobj_put(&obj); } - // Insert the new vmarea into the map - vmmap_insert(map, new_vmarea); - - // set ret val and return 0 - if (new_vma) + // now that vma is ready, set it + vmmap_insert(map, vma); + if (new_vma != NULL) { - *new_vma = new_vmarea; + *new_vma = vma; } + return 0; } @@ -558,13 +567,15 @@ long vmmap_remove(vmmap_t *map, size_t lopage, size_t npages) // Set the fields of the new vmarea new_vmarea->vma_start = lopage + npages; new_vmarea->vma_end = vma->vma_end; - new_vmarea->vma_off = vma->vma_off + (new_vmarea->vma_start - vma->vma_start); + new_vmarea->vma_off += lopage + npages - vma->vma_start; new_vmarea->vma_prot = vma->vma_prot; new_vmarea->vma_flags = vma->vma_flags; - new_vmarea->vma_vmmap = map; + // new_vmarea->vma_vmmap = map; + mobj_lock(vma->vma_obj); new_vmarea->vma_obj = vma->vma_obj; // increment the refcount of the object associated with the vmarea mobj_ref(new_vmarea->vma_obj); + mobj_unlock(vma->vma_obj); // Shorten the length of the old vmarea vma->vma_end = lopage; @@ -574,13 +585,12 @@ long vmmap_remove(vmmap_t *map, size_t lopage, size_t npages) // call pt_unmap_range() and tlb_flush_range() to clean the pagetables and TLB pt_unmap_range( - map->vmm_proc->p_pml4, - PN_TO_ADDR(lopage), - PN_TO_ADDR(lopage + npages) - ); + curproc->p_pml4, + PN_TO_ADDR(lopage), + PN_TO_ADDR(lopage + npages)); tlb_flush_range( - map->vmm_proc->p_pml4, - PN_TO_ADDR(lopage + npages) - PN_TO_ADDR(lopage) + PN_TO_ADDR(lopage), + npages ); } @@ -589,15 +599,15 @@ long vmmap_remove(vmmap_t *map, size_t lopage, size_t npages) { // shorten the length of the mapping vma->vma_end = lopage; + // call pt_unmap_range() and tlb_flush_range() to clean the pagetables and TLB pt_unmap_range( - map->vmm_proc->p_pml4, - PN_TO_ADDR(lopage), - PN_TO_ADDR(lopage + npages) - ); + curproc->p_pml4, + PN_TO_ADDR(lopage), + PN_TO_ADDR(lopage + npages)); tlb_flush_range( - map->vmm_proc->p_pml4, - PN_TO_ADDR(lopage + npages) - PN_TO_ADDR(lopage) + PN_TO_ADDR(lopage), + npages ); } @@ -605,18 +615,17 @@ long vmmap_remove(vmmap_t *map, size_t lopage, size_t npages) else if (vma->vma_start >= lopage && vma->vma_end > lopage + npages && vma->vma_start < lopage + npages) { // move the beginning of the mapping and shorten its length - vma->vma_off += (lopage + npages - vma->vma_start); + vma->vma_off += lopage + npages - vma->vma_start; vma->vma_start = lopage + npages; // call pt_unmap_range() and tlb_flush_range() to clean the pagetables and TLB pt_unmap_range( - map->vmm_proc->p_pml4, - PN_TO_ADDR(lopage), - PN_TO_ADDR(lopage + npages) - ); + curproc->p_pml4, + PN_TO_ADDR(lopage), + PN_TO_ADDR(lopage + npages)); tlb_flush_range( - map->vmm_proc->p_pml4, - PN_TO_ADDR(lopage + npages) - PN_TO_ADDR(lopage) + PN_TO_ADDR(lopage), + npages ); } @@ -629,13 +638,12 @@ long vmmap_remove(vmmap_t *map, size_t lopage, size_t npages) // call pt_unmap_range() and tlb_flush_range() to clean the pagetables and TLB pt_unmap_range( - map->vmm_proc->p_pml4, - PN_TO_ADDR(lopage), - PN_TO_ADDR(lopage + npages) - ); + curproc->p_pml4, + PN_TO_ADDR(lopage), + PN_TO_ADDR(lopage + npages)); tlb_flush_range( - map->vmm_proc->p_pml4, - PN_TO_ADDR(lopage + npages) - PN_TO_ADDR(lopage) + PN_TO_ADDR(lopage), + npages ); } } @@ -717,11 +725,11 @@ long vmmap_read(vmmap_t *map, const void *vaddr, void *buf, size_t count) } // Read from the pframe and copy it into buf - void *cursor = (void *)(bytes_read + vaddr); + void *cursor = bytes_read + vaddr; size_t bytes_this_iteration = MIN(PAGE_SIZE - PAGE_OFFSET(cursor), count - bytes_read); memcpy( (void *) buf + bytes_read, - (void *)pf->pf_addr + PAGE_OFFSET(cursor), + (void *) pf->pf_addr + PAGE_OFFSET(cursor), bytes_this_iteration ); @@ -767,7 +775,7 @@ long vmmap_write(vmmap_t *map, void *vaddr, const void *buf, size_t count) size_t vfn = ADDR_TO_PN(vaddr); size_t end_vfn = ADDR_TO_PN(vaddr + count); size_t bytes_written = 0; - while(vfn < end_vfn) + while(vfn <= end_vfn) { // Lookup the vmarea for this page number vmarea_t *vma = vmmap_lookup(map, vfn); @@ -787,7 +795,7 @@ long vmmap_write(vmmap_t *map, void *vaddr, const void *buf, size_t count) } // Write to the pframe, copying data from buf - void *cursor = (void *)(bytes_written + vaddr); + void *cursor = bytes_written + vaddr; size_t bytes_this_iteration = MIN(PAGE_SIZE - PAGE_OFFSET(cursor), count - bytes_written); memcpy( (void *)pf->pf_addr + PAGE_OFFSET(cursor), @@ -795,9 +803,8 @@ long vmmap_write(vmmap_t *map, void *vaddr, const void *buf, size_t count) bytes_this_iteration ); - // Dirty the page + // Dirty the pframe pf->pf_dirty = 1; - // Unlock the pframe pframe_release(&pf); |