[PATCH] mm: Fix pud_alloc_track()

[Joerg Roedel]

From: Joerg Roedel <jroe...@suse.de>

The pud_alloc_track() needs to do different checks based on whether
__ARCH_HAS_5LEVEL_HACK is defined, like it already does in
pud_alloc(). Otherwise it causes boot failures on PowerPC.

Provide the correct implementations for both possible settings of
__ARCH_HAS_5LEVEL_HACK to fix the boot problems.

Reported-by: Abdul Haleem <abdha...@linux.vnet.ibm.com>
Tested-by: Abdul Haleem <abdha...@linux.vnet.ibm.com>
Tested-by: Satheesh Rajendran <sathn...@linux.vnet.ibm.com>
Fixes: d8626138009b ("mm: add functions to track page directory modifications")
Signed-off-by: Joerg Roedel <jroe...@suse.de>
---
 include/asm-generic/5level-fixup.h |  5 +++++
 include/linux/mm.h                 | 26 +++++++++++++-------------
 2 files changed, 18 insertions(+), 13 deletions(-)

diff --git a/include/asm-generic/5level-fixup.h 
b/include/asm-generic/5level-fixup.h
index 58046ddc08d0..afbab31fbd7e 100644
--- a/include/asm-generic/5level-fixup.h
+++ b/include/asm-generic/5level-fixup.h
@@ -17,6 +17,11 @@
        ((unlikely(pgd_none(*(p4d))) && __pud_alloc(mm, p4d, address)) ? \
                NULL : pud_offset(p4d, address))
 
+#define pud_alloc_track(mm, p4d, address, mask)                                
        \
+       ((unlikely(pgd_none(*(p4d))) &&                                         
\
+         (__pud_alloc(mm, p4d, address) || 
({*(mask)|=PGTBL_P4D_MODIFIED;0;})))?       \
+         NULL : pud_offset(p4d, address))
+
 #define p4d_alloc(mm, pgd, address)            (pgd)
 #define p4d_alloc_track(mm, pgd, address, mask)        (pgd)
 #define p4d_offset(pgd, start)                 (pgd)
diff --git a/include/linux/mm.h b/include/linux/mm.h
index 66e0977f970a..ad3b31c5bcc3 100644
--- a/include/linux/mm.h
+++ b/include/linux/mm.h
@@ -2088,35 +2088,35 @@ static inline pud_t *pud_alloc(struct mm_struct *mm, 
p4d_t *p4d,
                NULL : pud_offset(p4d, address);
 }
 
-static inline p4d_t *p4d_alloc_track(struct mm_struct *mm, pgd_t *pgd,
+static inline pud_t *pud_alloc_track(struct mm_struct *mm, p4d_t *p4d,
                                     unsigned long address,
                                     pgtbl_mod_mask *mod_mask)
-
 {
-       if (unlikely(pgd_none(*pgd))) {
-               if (__p4d_alloc(mm, pgd, address))
+       if (unlikely(p4d_none(*p4d))) {
+               if (__pud_alloc(mm, p4d, address))
                        return NULL;
-               *mod_mask |= PGTBL_PGD_MODIFIED;
+               *mod_mask |= PGTBL_P4D_MODIFIED;
        }
 
-       return p4d_offset(pgd, address);
+       return pud_offset(p4d, address);
 }
 
-#endif /* !__ARCH_HAS_5LEVEL_HACK */
-
-static inline pud_t *pud_alloc_track(struct mm_struct *mm, p4d_t *p4d,
+static inline p4d_t *p4d_alloc_track(struct mm_struct *mm, pgd_t *pgd,
                                     unsigned long address,
                                     pgtbl_mod_mask *mod_mask)
+
 {
-       if (unlikely(p4d_none(*p4d))) {
-               if (__pud_alloc(mm, p4d, address))
+       if (unlikely(pgd_none(*pgd))) {
+               if (__p4d_alloc(mm, pgd, address))
                        return NULL;
-               *mod_mask |= PGTBL_P4D_MODIFIED;
+               *mod_mask |= PGTBL_PGD_MODIFIED;
        }
 
-       return pud_offset(p4d, address);
+       return p4d_offset(pgd, address);
 }
 
+#endif /* !__ARCH_HAS_5LEVEL_HACK */
+
 static inline pmd_t *pmd_alloc(struct mm_struct *mm, pud_t *pud, unsigned long 
address)
 {
        return (unlikely(pud_none(*pud)) && __pmd_alloc(mm, pud, address))?
-- 
2.26.2