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Diffstat (limited to 'arch/x86/mm/gup.c')
-rw-r--r--arch/x86/mm/gup.c47
1 files changed, 29 insertions, 18 deletions
diff --git a/arch/x86/mm/gup.c b/arch/x86/mm/gup.c
index d8a798d8bf50..b8b6a60b32cf 100644
--- a/arch/x86/mm/gup.c
+++ b/arch/x86/mm/gup.c
@@ -11,6 +11,7 @@
#include <linux/swap.h>
#include <linux/memremap.h>
+#include <asm/mmu_context.h>
#include <asm/pgtable.h>
static inline pte_t gup_get_pte(pte_t *ptep)
@@ -75,6 +76,28 @@ static void undo_dev_pagemap(int *nr, int nr_start, struct page **pages)
}
/*
+ * 'pteval' can come from a pte, pmd or pud. We only check
+ * _PAGE_PRESENT, _PAGE_USER, and _PAGE_RW in here which are the
+ * same value on all 3 types.
+ */
+static inline int pte_allows_gup(unsigned long pteval, int write)
+{
+ unsigned long need_pte_bits = _PAGE_PRESENT|_PAGE_USER;
+
+ if (write)
+ need_pte_bits |= _PAGE_RW;
+
+ if ((pteval & need_pte_bits) != need_pte_bits)
+ return 0;
+
+ /* Check memory protection keys permissions. */
+ if (!__pkru_allows_pkey(pte_flags_pkey(pteval), write))
+ return 0;
+
+ return 1;
+}
+
+/*
* The performance critical leaf functions are made noinline otherwise gcc
* inlines everything into a single function which results in too much
* register pressure.
@@ -83,14 +106,9 @@ static noinline int gup_pte_range(pmd_t pmd, unsigned long addr,
unsigned long end, int write, struct page **pages, int *nr)
{
struct dev_pagemap *pgmap = NULL;
- unsigned long mask;
int nr_start = *nr;
pte_t *ptep;
- mask = _PAGE_PRESENT|_PAGE_USER;
- if (write)
- mask |= _PAGE_RW;
-
ptep = pte_offset_map(&pmd, addr);
do {
pte_t pte = gup_get_pte(ptep);
@@ -109,7 +127,8 @@ static noinline int gup_pte_range(pmd_t pmd, unsigned long addr,
pte_unmap(ptep);
return 0;
}
- } else if ((pte_flags(pte) & (mask | _PAGE_SPECIAL)) != mask) {
+ } else if (!pte_allows_gup(pte_val(pte), write) ||
+ pte_special(pte)) {
pte_unmap(ptep);
return 0;
}
@@ -131,7 +150,7 @@ static inline void get_head_page_multiple(struct page *page, int nr)
{
VM_BUG_ON_PAGE(page != compound_head(page), page);
VM_BUG_ON_PAGE(page_count(page) == 0, page);
- atomic_add(nr, &page->_count);
+ page_ref_add(page, nr);
SetPageReferenced(page);
}
@@ -164,14 +183,10 @@ static int __gup_device_huge_pmd(pmd_t pmd, unsigned long addr,
static noinline int gup_huge_pmd(pmd_t pmd, unsigned long addr,
unsigned long end, int write, struct page **pages, int *nr)
{
- unsigned long mask;
struct page *head, *page;
int refs;
- mask = _PAGE_PRESENT|_PAGE_USER;
- if (write)
- mask |= _PAGE_RW;
- if ((pmd_flags(pmd) & mask) != mask)
+ if (!pte_allows_gup(pmd_val(pmd), write))
return 0;
VM_BUG_ON(!pfn_valid(pmd_pfn(pmd)));
@@ -231,14 +246,10 @@ static int gup_pmd_range(pud_t pud, unsigned long addr, unsigned long end,
static noinline int gup_huge_pud(pud_t pud, unsigned long addr,
unsigned long end, int write, struct page **pages, int *nr)
{
- unsigned long mask;
struct page *head, *page;
int refs;
- mask = _PAGE_PRESENT|_PAGE_USER;
- if (write)
- mask |= _PAGE_RW;
- if ((pud_flags(pud) & mask) != mask)
+ if (!pte_allows_gup(pud_val(pud), write))
return 0;
/* hugepages are never "special" */
VM_BUG_ON(pud_flags(pud) & _PAGE_SPECIAL);
@@ -422,7 +433,7 @@ slow_irqon:
start += nr << PAGE_SHIFT;
pages += nr;
- ret = get_user_pages_unlocked(current, mm, start,
+ ret = get_user_pages_unlocked(start,
(end - start) >> PAGE_SHIFT,
write, 0, pages);