[PATCH 4.4 02/45] thp: fix MADV_DONTNEED vs clear soft dirty race

[Greg Kroah-Hartman]

4.4-stable review patch.  If anyone has any objections, please let me know.

--

From: Kirill A. Shutemov 

commit 5b7abeae3af8c08c577e599dd0578b9e3ee6687b upstream.

Yet another instance of the same race.

Fix is identical to change_huge_pmd().

See "thp: fix MADV_DONTNEED vs.  numa balancing race" for more details.

Link: 
http://lkml.kernel.org/r/20170302151034.27829-5-kirill.shute...@linux.intel.com
Signed-off-by: Kirill A. Shutemov 
Cc: Andrea Arcangeli 
Cc: Hillf Danton 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds 
Signed-off-by: Greg Kroah-Hartman 

---
 fs/proc/task_mmu.c |9 -
 1 file changed, 8 insertions(+), 1 deletion(-)

--- a/fs/proc/task_mmu.c
+++ b/fs/proc/task_mmu.c
@@ -803,7 +803,14 @@ static inline void clear_soft_dirty(stru
 static inline void clear_soft_dirty_pmd(struct vm_area_struct *vma,
unsigned long addr, pmd_t *pmdp)
 {
-   pmd_t pmd = pmdp_huge_get_and_clear(vma->vm_mm, addr, pmdp);
+   pmd_t pmd = *pmdp;
+
+   /* See comment in change_huge_pmd() */
+   pmdp_invalidate(vma, addr, pmdp);
+   if (pmd_dirty(*pmdp))
+   pmd = pmd_mkdirty(pmd);
+   if (pmd_young(*pmdp))
+   pmd = pmd_mkyoung(pmd);
 
pmd = pmd_wrprotect(pmd);
pmd = pmd_clear_soft_dirty(pmd);

[PATCH 4.4 02/45] thp: fix MADV_DONTNEED vs clear soft dirty race

[Greg Kroah-Hartman]

4.4-stable review patch.  If anyone has any objections, please let me know.

--

From: Kirill A. Shutemov 

commit 5b7abeae3af8c08c577e599dd0578b9e3ee6687b upstream.

Yet another instance of the same race.

Fix is identical to change_huge_pmd().

See "thp: fix MADV_DONTNEED vs.  numa balancing race" for more details.

Link: 
http://lkml.kernel.org/r/20170302151034.27829-5-kirill.shute...@linux.intel.com
Signed-off-by: Kirill A. Shutemov 
Cc: Andrea Arcangeli 
Cc: Hillf Danton 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds 
Signed-off-by: Greg Kroah-Hartman 

---
 fs/proc/task_mmu.c |9 -
 1 file changed, 8 insertions(+), 1 deletion(-)

--- a/fs/proc/task_mmu.c
+++ b/fs/proc/task_mmu.c
@@ -803,7 +803,14 @@ static inline void clear_soft_dirty(stru
 static inline void clear_soft_dirty_pmd(struct vm_area_struct *vma,
unsigned long addr, pmd_t *pmdp)
 {
-   pmd_t pmd = pmdp_huge_get_and_clear(vma->vm_mm, addr, pmdp);
+   pmd_t pmd = *pmdp;
+
+   /* See comment in change_huge_pmd() */
+   pmdp_invalidate(vma, addr, pmdp);
+   if (pmd_dirty(*pmdp))
+   pmd = pmd_mkdirty(pmd);
+   if (pmd_young(*pmdp))
+   pmd = pmd_mkyoung(pmd);
 
pmd = pmd_wrprotect(pmd);
pmd = pmd_clear_soft_dirty(pmd);