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authorLinus Torvalds <torvalds@linux-foundation.org>2017-03-10 19:59:07 +0300
committerLinus Torvalds <torvalds@linux-foundation.org>2017-03-10 19:59:07 +0300
commitbaeedc7158da5b0f489d04125ba6adfba532a6f7 (patch)
tree1f42b5cd4a961ed10673578a28602dd13d09ab99 /fs/userfaultfd.c
parent8fe3ccaed080a7804bc459c42e0419253973be92 (diff)
parent90eceff1a375f6ffa78caf8654e787c0a8a591ef (diff)
downloadlinux-baeedc7158da5b0f489d04125ba6adfba532a6f7.tar.xz
Merge branch 'prep-for-5level'
Merge 5-level page table prep from Kirill Shutemov: "Here's relatively low-risk part of 5-level paging patchset. Merging it now will make x86 5-level paging enabling in v4.12 easier. The first patch is actually x86-specific: detect 5-level paging support. It boils down to single define. The rest of patchset converts Linux MMU abstraction from 4- to 5-level paging. Enabling of new abstraction in most cases requires adding single line of code in arch-specific code. The rest is taken care by asm-generic/. Changes to mm/ code are mostly mechanical: add support for new page table level -- p4d_t -- where we deal with pud_t now. v2: - fix build on microblaze (Michal); - comment for __ARCH_HAS_5LEVEL_HACK in kasan_populate_zero_shadow(); - acks from Michal" * emailed patches from Kirill A Shutemov <kirill.shutemov@linux.intel.com>: mm: introduce __p4d_alloc() mm: convert generic code to 5-level paging asm-generic: introduce <asm-generic/pgtable-nop4d.h> arch, mm: convert all architectures to use 5level-fixup.h asm-generic: introduce __ARCH_USE_5LEVEL_HACK asm-generic: introduce 5level-fixup.h x86/cpufeature: Add 5-level paging detection
Diffstat (limited to 'fs/userfaultfd.c')
-rw-r--r--fs/userfaultfd.c6
1 files changed, 5 insertions, 1 deletions
diff --git a/fs/userfaultfd.c b/fs/userfaultfd.c
index 2bb1c72380f2..1d227b0fcf49 100644
--- a/fs/userfaultfd.c
+++ b/fs/userfaultfd.c
@@ -265,6 +265,7 @@ static inline bool userfaultfd_must_wait(struct userfaultfd_ctx *ctx,
{
struct mm_struct *mm = ctx->mm;
pgd_t *pgd;
+ p4d_t *p4d;
pud_t *pud;
pmd_t *pmd, _pmd;
pte_t *pte;
@@ -275,7 +276,10 @@ static inline bool userfaultfd_must_wait(struct userfaultfd_ctx *ctx,
pgd = pgd_offset(mm, address);
if (!pgd_present(*pgd))
goto out;
- pud = pud_offset(pgd, address);
+ p4d = p4d_offset(pgd, address);
+ if (!p4d_present(*p4d))
+ goto out;
+ pud = pud_offset(p4d, address);
if (!pud_present(*pud))
goto out;
pmd = pmd_offset(pud, address);