if (pages)
foll_flags |= FOLL_GET;
if (!write && !(vma->vm_flags & VM_LOCKED) &&
- (!vma->vm_ops || !vma->vm_ops->nopage))
+ (!vma->vm_ops || (!vma->vm_ops->nopage &&
+ !vma->vm_ops->fault)))
foll_flags |= FOLL_ANON;
do {
}
/*
- * do_no_page() tries to create a new page mapping. It aggressively
+ * __do_fault() tries to create a new page mapping. It aggressively
* tries to share with existing pages, but makes a separate copy if
- * the "write_access" parameter is true in order to avoid the next
- * page fault.
+ * the FAULT_FLAG_WRITE is set in the flags parameter in order to avoid
+ * the next page fault.
*
* As this is called only for pages that do not currently exist, we
* do not need to flush old virtual caches or the TLB.
* but allow concurrent faults), and pte mapped but not yet locked.
* We return with mmap_sem still held, but pte unmapped and unlocked.
*/
-static int do_no_page(struct mm_struct *mm, struct vm_area_struct *vma,
+static int __do_fault(struct mm_struct *mm, struct vm_area_struct *vma,
unsigned long address, pte_t *page_table, pmd_t *pmd,
- int write_access)
+ pgoff_t pgoff, unsigned int flags, pte_t orig_pte)
{
spinlock_t *ptl;
- struct page *page, *nopage_page;
+ struct page *page, *faulted_page;
pte_t entry;
- int ret = VM_FAULT_MINOR;
int anon = 0;
struct page *dirty_page = NULL;
+ struct fault_data fdata;
+
+ fdata.address = address & PAGE_MASK;
+ fdata.pgoff = pgoff;
+ fdata.flags = flags;
pte_unmap(page_table);
BUG_ON(vma->vm_flags & VM_PFNMAP);
- nopage_page = vma->vm_ops->nopage(vma, address & PAGE_MASK, &ret);
- /* no page was available -- either SIGBUS, OOM or REFAULT */
- if (unlikely(nopage_page == NOPAGE_SIGBUS))
- return VM_FAULT_SIGBUS;
- else if (unlikely(nopage_page == NOPAGE_OOM))
- return VM_FAULT_OOM;
- else if (unlikely(nopage_page == NOPAGE_REFAULT))
- return VM_FAULT_MINOR;
+ if (likely(vma->vm_ops->fault)) {
+ fdata.type = -1;
+ faulted_page = vma->vm_ops->fault(vma, &fdata);
+ WARN_ON(fdata.type == -1);
+ if (unlikely(!faulted_page))
+ return fdata.type;
+ } else {
+ /* Legacy ->nopage path */
+ fdata.type = VM_FAULT_MINOR;
+ faulted_page = vma->vm_ops->nopage(vma, address & PAGE_MASK,
+ &fdata.type);
+ /* no page was available -- either SIGBUS or OOM */
+ if (unlikely(faulted_page == NOPAGE_SIGBUS))
+ return VM_FAULT_SIGBUS;
+ else if (unlikely(faulted_page == NOPAGE_OOM))
+ return VM_FAULT_OOM;
+ }
- BUG_ON(vma->vm_flags & VM_CAN_INVALIDATE && !PageLocked(nopage_page));
/*
- * For consistency in subsequent calls, make the nopage_page always
+ * For consistency in subsequent calls, make the faulted_page always
* locked.
*/
if (unlikely(!(vma->vm_flags & VM_CAN_INVALIDATE)))
- lock_page(nopage_page);
+ lock_page(faulted_page);
+ else
+ BUG_ON(!PageLocked(faulted_page));
/*
* Should we do an early C-O-W break?
*/
- page = nopage_page;
- if (write_access) {
+ page = faulted_page;
+ if (flags & FAULT_FLAG_WRITE) {
if (!(vma->vm_flags & VM_SHARED)) {
+ anon = 1;
if (unlikely(anon_vma_prepare(vma))) {
- ret = VM_FAULT_OOM;
- goto out_error;
+ fdata.type = VM_FAULT_OOM;
+ goto out;
}
page = alloc_page_vma(GFP_HIGHUSER_MOVABLE, vma, address);
if (!page) {
- ret = VM_FAULT_OOM;
- goto out_error;
+ fdata.type = VM_FAULT_OOM;
+ goto out;
}
- copy_user_highpage(page, nopage_page, address, vma);
- anon = 1;
+ copy_user_highpage(page, faulted_page, address, vma);
} else {
- /* if the page will be shareable, see if the backing
+ /*
+ * If the page will be shareable, see if the backing
* address space wants to know that the page is about
- * to become writable */
+ * to become writable
+ */
if (vma->vm_ops->page_mkwrite &&
vma->vm_ops->page_mkwrite(vma, page) < 0) {
- ret = VM_FAULT_SIGBUS;
- goto out_error;
+ fdata.type = VM_FAULT_SIGBUS;
+ anon = 1; /* no anon but release faulted_page */
+ goto out;
}
}
+
}
page_table = pte_offset_map_lock(mm, pmd, address, &ptl);
* handle that later.
*/
/* Only go through if we didn't race with anybody else... */
- if (likely(pte_none(*page_table))) {
+ if (likely(pte_same(*page_table, orig_pte))) {
flush_icache_page(vma, page);
entry = mk_pte(page, vma->vm_page_prot);
- if (write_access)
+ if (flags & FAULT_FLAG_WRITE)
entry = maybe_mkwrite(pte_mkdirty(entry), vma);
set_pte_at(mm, address, page_table, entry);
if (anon) {
} else {
inc_mm_counter(mm, file_rss);
page_add_file_rmap(page);
- if (write_access) {
+ if (flags & FAULT_FLAG_WRITE) {
dirty_page = page;
get_page(dirty_page);
}
if (anon)
page_cache_release(page);
else
- anon = 1; /* not anon, but release nopage_page */
+ anon = 1; /* no anon but release faulted_page */
}
pte_unmap_unlock(page_table, ptl);
out:
- unlock_page(nopage_page);
+ unlock_page(faulted_page);
if (anon)
- page_cache_release(nopage_page);
+ page_cache_release(faulted_page);
else if (dirty_page) {
set_page_dirty_balance(dirty_page);
put_page(dirty_page);
}
- return ret;
+ return fdata.type;
+}
-out_error:
- anon = 1; /* relase nopage_page */
- goto out;
+static int do_linear_fault(struct mm_struct *mm, struct vm_area_struct *vma,
+ unsigned long address, pte_t *page_table, pmd_t *pmd,
+ int write_access, pte_t orig_pte)
+{
+ pgoff_t pgoff = (((address & PAGE_MASK)
+ - vma->vm_start) >> PAGE_CACHE_SHIFT) + vma->vm_pgoff;
+ unsigned int flags = (write_access ? FAULT_FLAG_WRITE : 0);
+
+ return __do_fault(mm, vma, address, page_table, pmd, pgoff, flags, orig_pte);
+}
+
+static int do_nonlinear_fault(struct mm_struct *mm, struct vm_area_struct *vma,
+ unsigned long address, pte_t *page_table, pmd_t *pmd,
+ int write_access, pgoff_t pgoff, pte_t orig_pte)
+{
+ unsigned int flags = FAULT_FLAG_NONLINEAR |
+ (write_access ? FAULT_FLAG_WRITE : 0);
+
+ return __do_fault(mm, vma, address, page_table, pmd, pgoff, flags, orig_pte);
}
/*
print_bad_pte(vma, orig_pte, address);
return VM_FAULT_OOM;
}
- /* We can then assume vm->vm_ops && vma->vm_ops->populate */
pgoff = pte_to_pgoff(orig_pte);
+
+ if (vma->vm_ops && vma->vm_ops->fault)
+ return do_nonlinear_fault(mm, vma, address, page_table, pmd,
+ write_access, pgoff, orig_pte);
+
+ /* We can then assume vm->vm_ops && vma->vm_ops->populate */
err = vma->vm_ops->populate(vma, address & PAGE_MASK, PAGE_SIZE,
vma->vm_page_prot, pgoff, 0);
if (err == -ENOMEM)
if (!pte_present(entry)) {
if (pte_none(entry)) {
if (vma->vm_ops) {
- if (vma->vm_ops->nopage)
- return do_no_page(mm, vma, address,
- pte, pmd,
- write_access);
+ if (vma->vm_ops->fault || vma->vm_ops->nopage)
+ return do_linear_fault(mm, vma, address,
+ pte, pmd, write_access, entry);
if (unlikely(vma->vm_ops->nopfn))
return do_no_pfn(mm, vma, address, pte,
pmd, write_access);
projects / mirror_ubuntu-zesty-kernel.git / blobdiff