linux-next: build failure after merge of the akpm tree

From: Stephen Rothwell
Date: Mon Apr 10 2017 - 03:51:12 EST


Hi Andrew,

After merging the akpm tree, today's linux-next build (x86_64
allmodconfig) failed like this:

mm/migrate.c: In function 'migrate_vma_insert_page':
mm/migrate.c:2491:23: error: passing argument 2 of 'pud_alloc' from incompatible pointer type [-Werror=incompatible-pointer-types]
pudp = pud_alloc(mm, pgdp, addr);
^
In file included from include/linux/migrate.h:4:0,
from mm/migrate.c:15:
include/linux/mm.h:1677:22: note: expected 'p4d_t * {aka struct <anonymous> *}' but argument is of type 'pgd_t * {aka struct <anonymous> *}'
static inline pud_t *pud_alloc(struct mm_struct *mm, p4d_t *p4d,
^

Caused by patch

"mm/migrate: allow migrate_vma() to alloc new page on empty entry"

interacting with commit

c2febafc6773 ("mm: convert generic code to 5-level paging")

from Linus' tree (v4.11-rc2).

I applied the following fix patch:

From: Stephen Rothwell <sfr@xxxxxxxxxxxxxxxx>
Date: Mon, 10 Apr 2017 17:09:15 +1000
Subject: [PATCH] mm/migrate: allow migrate_vma() to alloc new page on empty
entry fix

Signed-off-by: Stephen Rothwell <sfr@xxxxxxxxxxxxxxxx>
---
mm/migrate.c | 6 +++++-
1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/mm/migrate.c b/mm/migrate.c
index e4b555f9a689..7958dfa01b16 100644
--- a/mm/migrate.c
+++ b/mm/migrate.c
@@ -2478,6 +2478,7 @@ static void migrate_vma_insert_page(struct migrate_vma *migrate,
struct mem_cgroup *memcg;
spinlock_t *ptl;
pgd_t *pgdp;
+ p4d_t *p4dp;
pud_t *pudp;
pmd_t *pmdp;
pte_t *ptep;
@@ -2488,7 +2489,10 @@ static void migrate_vma_insert_page(struct migrate_vma *migrate,
goto abort;

pgdp = pgd_offset(mm, addr);
- pudp = pud_alloc(mm, pgdp, addr);
+ p4dp = p4d_alloc(mm, pgdp, addr);
+ if (!p4dp)
+ goto abort;
+ pudp = pud_alloc(mm, p4dp, addr);
if (!pudp)
goto abort;
pmdp = pmd_alloc(mm, pudp, addr);
--
2.11.0

--
Cheers,
Stephen Rothwell