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-rw-r--r--mm/mincore.c263
1 files changed, 151 insertions, 112 deletions
diff --git a/mm/mincore.c b/mm/mincore.c
index f77433c..9ac42dc 100644
--- a/mm/mincore.c
+++ b/mm/mincore.c
@@ -19,6 +19,40 @@
#include <asm/uaccess.h>
#include <asm/pgtable.h>
+static void mincore_hugetlb_page_range(struct vm_area_struct *vma,
+ unsigned long addr, unsigned long end,
+ unsigned char *vec)
+{
+#ifdef CONFIG_HUGETLB_PAGE
+ struct hstate *h;
+
+ h = hstate_vma(vma);
+ while (1) {
+ unsigned char present;
+ pte_t *ptep;
+ /*
+ * Huge pages are always in RAM for now, but
+ * theoretically it needs to be checked.
+ */
+ ptep = huge_pte_offset(current->mm,
+ addr & huge_page_mask(h));
+ present = ptep && !huge_pte_none(huge_ptep_get(ptep));
+ while (1) {
+ *vec = present;
+ vec++;
+ addr += PAGE_SIZE;
+ if (addr == end)
+ return;
+ /* check hugepage border */
+ if (!(addr & ~huge_page_mask(h)))
+ break;
+ }
+ }
+#else
+ BUG();
+#endif
+}
+
/*
* Later we can get more picky about what "in core" means precisely.
* For now, simply check to see if the page is in the page cache,
@@ -49,145 +83,150 @@ static unsigned char mincore_page(struct address_space *mapping, pgoff_t pgoff)
return present;
}
-/*
- * 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)
+static void mincore_unmapped_range(struct vm_area_struct *vma,
+ unsigned long addr, unsigned long end,
+ unsigned char *vec)
{
- pgd_t *pgd;
- pud_t *pud;
- pmd_t *pmd;
- pte_t *ptep;
- spinlock_t *ptl;
- unsigned long nr;
+ unsigned long nr = (end - addr) >> PAGE_SHIFT;
int i;
- pgoff_t 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;
-
-#ifdef CONFIG_HUGETLB_PAGE
- if (is_vm_hugetlb_page(vma)) {
- struct hstate *h;
- unsigned long nr_huge;
- unsigned char present;
+ if (vma->vm_file) {
+ pgoff_t pgoff;
- i = 0;
- nr = min(pages, (vma->vm_end - addr) >> PAGE_SHIFT);
- h = hstate_vma(vma);
- nr_huge = ((addr + pages * PAGE_SIZE - 1) >> huge_page_shift(h))
- - (addr >> huge_page_shift(h)) + 1;
- nr_huge = min(nr_huge,
- (vma->vm_end - addr) >> huge_page_shift(h));
- while (1) {
- /* hugepage always in RAM for now,
- * but generally it needs to be check */
- ptep = huge_pte_offset(current->mm,
- addr & huge_page_mask(h));
- present = !!(ptep &&
- !huge_pte_none(huge_ptep_get(ptep)));
- while (1) {
- vec[i++] = present;
- addr += PAGE_SIZE;
- /* reach buffer limit */
- if (i == nr)
- return nr;
- /* check hugepage border */
- if (!((addr & ~huge_page_mask(h))
- >> PAGE_SHIFT))
- break;
- }
- }
- return nr;
+ 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;
}
-#endif
-
- /*
- * Calculate how many pages there are left in the last level of the
- * PTE array for our address.
- */
- nr = PTRS_PER_PTE - ((addr >> PAGE_SHIFT) & (PTRS_PER_PTE-1));
-
- /*
- * Don't overrun this vma
- */
- nr = min(nr, (vma->vm_end - addr) >> PAGE_SHIFT);
-
- /*
- * Don't return more than the caller asked for
- */
- nr = min(nr, pages);
+}
- pgd = pgd_offset(vma->vm_mm, addr);
- if (pgd_none_or_clear_bad(pgd))
- goto none_mapped;
- pud = pud_offset(pgd, addr);
- if (pud_none_or_clear_bad(pud))
- goto none_mapped;
- pmd = pmd_offset(pud, addr);
- if (pmd_none_or_clear_bad(pmd))
- goto none_mapped;
+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);
- for (i = 0; i < nr; i++, ptep++, addr += PAGE_SIZE) {
- unsigned char present;
+ do {
pte_t pte = *ptep;
+ pgoff_t pgoff;
- if (pte_present(pte)) {
- present = 1;
-
- } else if (pte_none(pte)) {
- if (vma->vm_file) {
- pgoff = linear_page_index(vma, addr);
- present = mincore_page(vma->vm_file->f_mapping,
- pgoff);
- } else
- present = 0;
-
- } else if (pte_file(pte)) {
+ 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);
- present = mincore_page(vma->vm_file->f_mapping, pgoff);
-
+ *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 */
- present = 1;
+ *vec = 1;
} else {
#ifdef CONFIG_SWAP
pgoff = entry.val;
- present = mincore_page(&swapper_space, pgoff);
+ *vec = mincore_page(&swapper_space, pgoff);
#else
WARN_ON(1);
- present = 1;
+ *vec = 1;
#endif
}
}
+ vec++;
+ } while (ptep++, addr = next, addr != end);
+ pte_unmap_unlock(ptep - 1, ptl);
+}
- vec[i] = present;
- }
- pte_unmap_unlock(ptep-1, ptl);
+static void mincore_pmd_range(struct vm_area_struct *vma, pud_t *pud,
+ unsigned long addr, unsigned long end,
+ unsigned char *vec)
+{
+ unsigned long next;
+ pmd_t *pmd;
- return nr;
+ pmd = pmd_offset(pud, addr);
+ do {
+ next = pmd_addr_end(addr, end);
+ if (pmd_none_or_clear_bad(pmd))
+ mincore_unmapped_range(vma, addr, next, vec);
+ else
+ mincore_pte_range(vma, pmd, addr, next, vec);
+ vec += (next - addr) >> PAGE_SHIFT;
+ } while (pmd++, addr = next, addr != end);
+}
-none_mapped:
- if (vma->vm_file) {
- 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;
+static void mincore_pud_range(struct vm_area_struct *vma, pgd_t *pgd,
+ unsigned long addr, unsigned long end,
+ unsigned char *vec)
+{
+ unsigned long next;
+ pud_t *pud;
+
+ pud = pud_offset(pgd, addr);
+ do {
+ next = pud_addr_end(addr, end);
+ if (pud_none_or_clear_bad(pud))
+ mincore_unmapped_range(vma, addr, next, vec);
+ else
+ mincore_pmd_range(vma, pud, addr, next, vec);
+ vec += (next - addr) >> PAGE_SHIFT;
+ } while (pud++, addr = next, addr != end);
+}
+
+static void mincore_page_range(struct vm_area_struct *vma,
+ unsigned long addr, unsigned long end,
+ unsigned char *vec)
+{
+ unsigned long next;
+ pgd_t *pgd;
+
+ pgd = pgd_offset(vma->vm_mm, addr);
+ do {
+ next = pgd_addr_end(addr, end);
+ if (pgd_none_or_clear_bad(pgd))
+ mincore_unmapped_range(vma, addr, next, vec);
+ else
+ mincore_pud_range(vma, pgd, addr, next, vec);
+ vec += (next - addr) >> PAGE_SHIFT;
+ } while (pgd++, addr = next, addr != end);
+}
+
+/*
+ * 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 long pages, unsigned char *vec)
+{
+ struct vm_area_struct *vma;
+ unsigned long end;
+
+ vma = find_vma(current->mm, addr);
+ if (!vma || addr < vma->vm_start)
+ return -ENOMEM;
+
+ end = min(vma->vm_end, addr + (pages << PAGE_SHIFT));
+
+ if (is_vm_hugetlb_page(vma)) {
+ mincore_hugetlb_page_range(vma, addr, end, vec);
+ return (end - addr) >> PAGE_SHIFT;
}
- return nr;
+ end = pmd_addr_end(addr, end);
+
+ if (is_vm_hugetlb_page(vma))
+ mincore_hugetlb_page_range(vma, addr, end, vec);
+ else
+ mincore_page_range(vma, addr, end, vec);
+
+ return (end - addr) >> PAGE_SHIFT;
}
/*
@@ -247,7 +286,7 @@ SYSCALL_DEFINE3(mincore, unsigned long, start, size_t, len,
* the temporary buffer size.
*/
down_read(&current->mm->mmap_sem);
- retval = do_mincore(start, tmp, min(pages, PAGE_SIZE));
+ retval = do_mincore(start, min(pages, PAGE_SIZE), tmp);
up_read(&current->mm->mmap_sem);
if (retval <= 0)
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