static void mincore_pte_range(struct vm_area_struct *vma, pmd_t *pmd,
unsigned long addr, unsigned long end,
unsigned char *vec)
{
unsigned long next;
spinlock_t *ptl;
pte_t *ptep;
ptep = pte_offset_map_lock(vma->vm_mm, pmd, addr, &ptl);
do {
pte_t pte = *ptep;
pgoff_t pgoff;
next = addr + PAGE_SIZE;
if (pte_none(pte))
mincore_unmapped_range(vma, addr, next, vec);
else if (pte_present(pte))
*vec = 1;
else if (pte_file(pte)) {
pgoff = pte_to_pgoff(pte);
*vec = mincore_page(vma->vm_file->f_mapping, pgoff);
} else { /* pte is a swap entry */
swp_entry_t entry = pte_to_swp_entry(pte);
if (is_migration_entry(entry)) {
/* migration entries are always uptodate */
*vec = 1;
} else {
#ifdef CONFIG_SWAP
pgoff = entry.val;
*vec = mincore_page(&swapper_space, pgoff);
#else
WARN_ON(1);
*vec = 1;
#endif
}
}
vec++;
} while (ptep++, addr = next, addr != end);
pte_unmap_unlock(ptep - 1, ptl);
}
static void mincore_unmapped_range(struct vm_area_struct *vma,
unsigned long addr, unsigned long end,
unsigned char *vec)
{
unsigned long nr = (end - addr) >> PAGE_SHIFT;
int i;
if (vma->vm_file) {
pgoff_t pgoff;
pgoff = linear_page_index(vma, addr);
for (i = 0; i < nr; i++, pgoff++)
vec[i] = mincore_page(vma->vm_file->f_mapping, pgoff);
} else {
for (i = 0; i < nr; i++)
vec[i] = 0;
}
}
/*
* Do a chunk of "sys_mincore()". We've already checked
* all the arguments, we hold the mmap semaphore: we should
* just return the amount of info we're asked for.
*/
static long do_mincore(unsigned long addr, unsigned char *vec, unsigned long pages)
{
unsigned long i, nr, pgoff;
struct vm_area_struct *vma = find_vma(current->mm, addr);
/*
* find_vma() didn't find anything above us, or we're
* in an unmapped hole in the address space: ENOMEM.
*/
if (!vma || addr < vma->vm_start)
return -ENOMEM;
/*
* Ok, got it. But check whether it's a segment we support
* mincore() on. Right now, we don't do any anonymous mappings.
*
* FIXME: This is just stupid. And returning ENOMEM is
* stupid too. We should just look at the page tables. But
* this is what we've traditionally done, so we'll just
* continue doing it.
*/
if (!vma->vm_file)
return -ENOMEM;
/*
* Calculate how many pages there are left in the vma, and
* what the pgoff is for our address.
*/
nr = (vma->vm_end - addr) >> PAGE_SHIFT;
if (nr > pages)
nr = pages;
pgoff = (addr - vma->vm_start) >> PAGE_SHIFT;
pgoff += vma->vm_pgoff;
/* And then we just fill the sucker in.. */
for (i = 0 ; i < nr; i++, pgoff++)
vec[i] = mincore_page(vma, pgoff);
return nr;
}
