From: Huang Ying <ying.hu...@intel.com>
Now, when the page table is walked in the implementation of
/proc/<pid>/pagemap, pmd_soft_dirty() is used for both the PMD huge
page map and the PMD migration entries. That is wrong,
pmd_swp_soft_dirty() should be used for the PMD migration entries
instead because the different page table entry flag is used.
Otherwise, the soft dirty information in /proc/<pid>/pagemap may be
wrong.
Cc: Michal Hocko <mho...@suse.com>
Cc: "Kirill A. Shutemov" <kirill.shute...@linux.intel.com>
Cc: David Rientjes <rient...@google.com>
Cc: Arnd Bergmann <a...@arndb.de>
Cc: Hugh Dickins <hu...@google.com>
Cc: "Jérôme Glisse" <jgli...@redhat.com>
Cc: Daniel Colascione <dan...@google.com>
Cc: Zi Yan <zi....@cs.rutgers.edu>
Cc: Naoya Horiguchi <n-horigu...@ah.jp.nec.com>
Signed-off-by: "Huang, Ying" <ying.hu...@intel.com>
Fixes: 84c3fc4e9c56 ("mm: thp: check pmd migration entry in common path")
---
fs/proc/task_mmu.c | 6 +++++-
1 file changed, 5 insertions(+), 1 deletion(-)
diff --git a/fs/proc/task_mmu.c b/fs/proc/task_mmu.c
index 2593a0c609d7..01aad772f8db 100644
--- a/fs/proc/task_mmu.c
+++ b/fs/proc/task_mmu.c
@@ -1311,13 +1311,15 @@ static int pagemap_pmd_range(pmd_t *pmdp, unsigned long
addr, unsigned long end,
pmd_t pmd = *pmdp;
struct page *page = NULL;
- if ((vma->vm_flags & VM_SOFTDIRTY) || pmd_soft_dirty(pmd))
+ if (vma->vm_flags & VM_SOFTDIRTY)
flags |= PM_SOFT_DIRTY;
if (pmd_present(pmd)) {
page = pmd_page(pmd);
flags |= PM_PRESENT;
+ if (pmd_soft_dirty(pmd))
+ flags |= PM_SOFT_DIRTY;
if (pm->show_pfn)
frame = pmd_pfn(pmd) +
((addr & ~PMD_MASK) >> PAGE_SHIFT);
@@ -1329,6 +1331,8 @@ static int pagemap_pmd_range(pmd_t *pmdp, unsigned long
addr, unsigned long end,
frame = swp_type(entry) |
(swp_offset(entry) << MAX_SWAPFILES_SHIFT);
flags |= PM_SWAP;
+ if (pmd_swp_soft_dirty(pmd))
+ flags |= PM_SOFT_DIRTY;
VM_BUG_ON(!is_pmd_migration_entry(pmd));
page = migration_entry_to_page(entry);
}
--
2.14.2
