From: Huang Ying <ying.huang@xxxxxxxxx> Subject: mm, /proc/pid/pagemap: fix soft dirty marking for PMD migration entry 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. As a result, /proc/pid/pagemap may report incorrect soft dirty information for PMD migration entries. Link: http://lkml.kernel.org/r/20171017081818.31795-1-ying.huang@xxxxxxxxx Fixes: 84c3fc4e9c56 ("mm: thp: check pmd migration entry in common path") Signed-off-by: "Huang, Ying" <ying.huang@xxxxxxxxx> Acked-by: Kirill A. Shutemov <kirill.shutemov@xxxxxxxxxxxxxxx> Acked-by: Naoya Horiguchi <n-horiguchi@xxxxxxxxxxxxx> Cc: Michal Hocko <mhocko@xxxxxxxx> Cc: David Rientjes <rientjes@xxxxxxxxxx> Cc: Arnd Bergmann <arnd@xxxxxxxx> Cc: Hugh Dickins <hughd@xxxxxxxxxx> Cc: "Jérôme Glisse" <jglisse@xxxxxxxxxx> Cc: Daniel Colascione <dancol@xxxxxxxxxx> Cc: Zi Yan <zi.yan@xxxxxxxxxxxxxx> Cc: Anshuman Khandual <khandual@xxxxxxxxxxxxxxxxxx> Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> --- fs/proc/task_mmu.c | 6 +++++- 1 file changed, 5 insertions(+), 1 deletion(-) diff -puN fs/proc/task_mmu.c~mm-pagemap-fix-soft-dirty-marking-for-pmd-migration-entry fs/proc/task_mmu.c --- a/fs/proc/task_mmu.c~mm-pagemap-fix-soft-dirty-marking-for-pmd-migration-entry +++ a/fs/proc/task_mmu.c @@ -1311,13 +1311,15 @@ static int pagemap_pmd_range(pmd_t *pmdp 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 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); } _ -- To unsubscribe from this list: send the line "unsubscribe mm-commits" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
