return err;
}
+pte_t * fastcall get_locked_pte(struct mm_struct *mm, unsigned long addr, spinlock_t **ptl)
+{
+ pgd_t * pgd = pgd_offset(mm, addr);
+ pud_t * pud = pud_alloc(mm, pgd, addr);
+ if (pud) {
+ pmd_t * pmd = pmd_alloc(mm, pud, addr);
+ if (pmd)
+ return pte_alloc_map_lock(mm, pmd, addr, ptl);
+ }
+ return NULL;
+}
+
+/*
+ * This is the old fallback for page remapping.
+ *
+ * For historical reasons, it only allows reserved pages. Only
+ * old drivers should use this, and they needed to mark their
+ * pages reserved for the old functions anyway.
+ */
+static int insert_page(struct mm_struct *mm, unsigned long addr, struct page *page, pgprot_t prot)
+{
+ int retval;
+ pte_t *pte;
+ spinlock_t *ptl;
+
+ retval = -EINVAL;
+ if (PageAnon(page))
+ goto out;
+ retval = -ENOMEM;
+ flush_dcache_page(page);
+ pte = get_locked_pte(mm, addr, &ptl);
+ if (!pte)
+ goto out;
+ retval = -EBUSY;
+ if (!pte_none(*pte))
+ goto out_unlock;
+
+ /* Ok, finally just insert the thing.. */
+ get_page(page);
+ inc_mm_counter(mm, file_rss);
+ page_add_file_rmap(page);
+ set_pte_at(mm, addr, pte, mk_pte(page, prot));
+
+ retval = 0;
+out_unlock:
+ pte_unmap_unlock(pte, ptl);
+out:
+ return retval;
+}
+
+/*
+ * This allows drivers to insert individual pages they've allocated
+ * into a user vma.
+ *
+ * The page has to be a nice clean _individual_ kernel allocation.
+ * If you allocate a compound page, you need to have marked it as
+ * such (__GFP_COMP), or manually just split the page up yourself
+ * (which is mainly an issue of doing "set_page_count(page, 1)" for
+ * each sub-page, and then freeing them one by one when you free
+ * them rather than freeing it as a compound page).
+ *
+ * NOTE! Traditionally this was done with "remap_pfn_range()" which
+ * took an arbitrary page protection parameter. This doesn't allow
+ * that. Your vma protection will have to be set up correctly, which
+ * means that if you want a shared writable mapping, you'd better
+ * ask for a shared writable mapping!
+ *
+ * The page does not need to be reserved.
+ */
+int vm_insert_page(struct vm_area_struct *vma, unsigned long addr, struct page *page)
+{
+ if (addr < vma->vm_start || addr >= vma->vm_end)
+ return -EFAULT;
+ if (!page_count(page))
+ return -EINVAL;
+ return insert_page(vma->vm_mm, addr, page, vma->vm_page_prot);
+}
+EXPORT_SYMBOL_GPL(vm_insert_page);
+
+/*
+ * Somebody does a pfn remapping that doesn't actually work as a vma.
+ *
+ * Do it as individual pages instead, and warn about it. It's bad form,
+ * and very inefficient.
+ */
+static int incomplete_pfn_remap(struct vm_area_struct *vma,
+ unsigned long start, unsigned long end,
+ unsigned long pfn, pgprot_t prot)
+{
+ static int warn = 10;
+ struct page *page;
+ int retval;
+
+ if (!(vma->vm_flags & VM_INCOMPLETE)) {
+ if (warn) {
+ warn--;
+ printk("%s does an incomplete pfn remapping", current->comm);
+ dump_stack();
+ }
+ }
+ vma->vm_flags |= VM_INCOMPLETE | VM_IO | VM_RESERVED;
+
+ if (start < vma->vm_start || end > vma->vm_end)
+ return -EINVAL;
+
+ if (!pfn_valid(pfn))
+ return -EINVAL;
+
+ page = pfn_to_page(pfn);
+ if (!PageReserved(page))
+ return -EINVAL;
+
+ retval = 0;
+ while (start < end) {
+ retval = insert_page(vma->vm_mm, start, page, prot);
+ if (retval < 0)
+ break;
+ start += PAGE_SIZE;
+ page++;
+ }
+ return retval;
+}
+
/*
* maps a range of physical memory into the requested pages. the old
* mappings are removed. any references to nonexistent pages results
struct mm_struct *mm = vma->vm_mm;
int err;
+ if (addr != vma->vm_start || end != vma->vm_end)
+ return incomplete_pfn_remap(vma, addr, end, pfn, prot);
+
/*
* Physically remapped pages are special. Tell the
* rest of the world about it:
*/
if (unlikely(!src)) {
void *kaddr = kmap_atomic(dst, KM_USER0);
- unsigned long left = __copy_from_user_inatomic(kaddr, (void __user *)va, PAGE_SIZE);
- if (left)
+ void __user *uaddr = (void __user *)(va & PAGE_MASK);
+
+ /*
+ * This really shouldn't fail, because the page is there
+ * in the page tables. But it might just be unreadable,
+ * in which case we just give up and fill the result with
+ * zeroes.
+ */
+ if (__copy_from_user_inatomic(kaddr, uaddr, PAGE_SIZE))
memset(kaddr, 0, PAGE_SIZE);
kunmap_atomic(kaddr, KM_USER0);
return;
unsigned long address, pte_t *page_table, pmd_t *pmd,
spinlock_t *ptl, pte_t orig_pte)
{
- struct page *old_page, *src_page, *new_page;
+ struct page *old_page, *new_page;
pte_t entry;
int ret = VM_FAULT_MINOR;
old_page = vm_normal_page(vma, address, orig_pte);
- src_page = old_page;
if (!old_page)
goto gotten;
int reuse = can_share_swap_page(old_page);
unlock_page(old_page);
if (reuse) {
- flush_cache_page(vma, address, pfn);
+ flush_cache_page(vma, address, pte_pfn(orig_pte));
entry = pte_mkyoung(orig_pte);
entry = maybe_mkwrite(pte_mkdirty(entry), vma);
ptep_set_access_flags(vma, address, page_table, entry, 1);
if (unlikely(anon_vma_prepare(vma)))
goto oom;
- if (src_page == ZERO_PAGE(address)) {
+ if (old_page == ZERO_PAGE(address)) {
new_page = alloc_zeroed_user_highpage(vma, address);
if (!new_page)
goto oom;
new_page = alloc_page_vma(GFP_HIGHUSER, vma, address);
if (!new_page)
goto oom;
- cow_user_page(new_page, src_page, address);
+ cow_user_page(new_page, old_page, address);
}
/*
}
} else
inc_mm_counter(mm, anon_rss);
- flush_cache_page(vma, address, pfn);
+ flush_cache_page(vma, address, pte_pfn(orig_pte));
entry = mk_pte(new_page, vma->vm_page_prot);
entry = maybe_mkwrite(pte_mkdirty(entry), vma);
ptep_establish(vma, address, page_table, entry);
int anon = 0;
pte_unmap(page_table);
+ BUG_ON(vma->vm_flags & VM_PFNMAP);
+
if (vma->vm_file) {
mapping = vma->vm_file->f_mapping;
sequence = mapping->truncate_count;
page = alloc_page_vma(GFP_HIGHUSER, vma, address);
if (!page)
goto oom;
- cow_user_page(page, new_page, address);
+ copy_user_highpage(page, new_page, address);
page_cache_release(new_page);
new_page = page;
anon = 1;
projects / linux-2.6 / blobdiff