summaryrefslogtreecommitdiffstats
path: root/mm/gup.c
diff options
context:
space:
mode:
authorIngo Molnar <mingo@kernel.org>2017-10-20 13:06:52 +0200
committerIngo Molnar <mingo@kernel.org>2017-10-20 13:06:52 +0200
commit967535223f9a8d95c187a8728480b569164cd4f4 (patch)
treeb68a403701555a747b25c903d8136d86a1a1c133 /mm/gup.c
parent5b65c4677a57a1d4414212f9995aa0e46a21ff80 (diff)
parentce56a86e2ade45d052b3228cdfebe913a1ae7381 (diff)
downloadlinux-967535223f9a8d95c187a8728480b569164cd4f4.tar.bz2
Merge branch 'x86/urgent' into x86/mm, to pick up fixes
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Diffstat (limited to 'mm/gup.c')
-rw-r--r--mm/gup.c31
1 files changed, 28 insertions, 3 deletions
diff --git a/mm/gup.c b/mm/gup.c
index 4a789f1c6a27..dfcde13f289a 100644
--- a/mm/gup.c
+++ b/mm/gup.c
@@ -234,6 +234,16 @@ static struct page *follow_pmd_mask(struct vm_area_struct *vma,
return page;
return no_page_table(vma, flags);
}
+retry:
+ if (!pmd_present(*pmd)) {
+ if (likely(!(flags & FOLL_MIGRATION)))
+ return no_page_table(vma, flags);
+ VM_BUG_ON(thp_migration_supported() &&
+ !is_pmd_migration_entry(*pmd));
+ if (is_pmd_migration_entry(*pmd))
+ pmd_migration_entry_wait(mm, pmd);
+ goto retry;
+ }
if (pmd_devmap(*pmd)) {
ptl = pmd_lock(mm, pmd);
page = follow_devmap_pmd(vma, address, pmd, flags);
@@ -247,7 +257,15 @@ static struct page *follow_pmd_mask(struct vm_area_struct *vma,
if ((flags & FOLL_NUMA) && pmd_protnone(*pmd))
return no_page_table(vma, flags);
+retry_locked:
ptl = pmd_lock(mm, pmd);
+ if (unlikely(!pmd_present(*pmd))) {
+ spin_unlock(ptl);
+ if (likely(!(flags & FOLL_MIGRATION)))
+ return no_page_table(vma, flags);
+ pmd_migration_entry_wait(mm, pmd);
+ goto retry_locked;
+ }
if (unlikely(!pmd_trans_huge(*pmd))) {
spin_unlock(ptl);
return follow_page_pte(vma, address, pmd, flags);
@@ -424,7 +442,7 @@ static int get_gate_page(struct mm_struct *mm, unsigned long address,
pud = pud_offset(p4d, address);
BUG_ON(pud_none(*pud));
pmd = pmd_offset(pud, address);
- if (pmd_none(*pmd))
+ if (!pmd_present(*pmd))
return -EFAULT;
VM_BUG_ON(pmd_trans_huge(*pmd));
pte = pte_offset_map(pmd, address);
@@ -438,6 +456,13 @@ static int get_gate_page(struct mm_struct *mm, unsigned long address,
if ((gup_flags & FOLL_DUMP) || !is_zero_pfn(pte_pfn(*pte)))
goto unmap;
*page = pte_page(*pte);
+
+ /*
+ * This should never happen (a device public page in the gate
+ * area).
+ */
+ if (is_device_public_page(*page))
+ goto unmap;
}
get_page(*page);
out:
@@ -1352,7 +1377,7 @@ static int gup_pte_range(pmd_t pmd, unsigned long addr, unsigned long end,
}
#endif /* __HAVE_ARCH_PTE_SPECIAL */
-#ifdef __HAVE_ARCH_PTE_DEVMAP
+#if defined(__HAVE_ARCH_PTE_DEVMAP) && defined(CONFIG_TRANSPARENT_HUGEPAGE)
static int __gup_device_huge(unsigned long pfn, unsigned long addr,
unsigned long end, struct page **pages, int *nr)
{
@@ -1534,7 +1559,7 @@ static int gup_pmd_range(pud_t pud, unsigned long addr, unsigned long end,
pmd_t pmd = READ_ONCE(*pmdp);
next = pmd_addr_end(addr, end);
- if (pmd_none(pmd))
+ if (!pmd_present(pmd))
return 0;
if (unlikely(pmd_trans_huge(pmd) || pmd_huge(pmd))) {