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

From: Stephen Rothwell <[email-masked]>
Date: Wed, 14 Mar 2018 16:45:49 +1100

Hi Andrew,

After merging the akpm-current tree, today's linux-next build (powerpc
ppc64_defconfig) failed like this:

In file included from include/linux/kernel.h:15:0,
                 from include/linux/list.h:9,
                 from mm/hugetlb.c:5:
mm/hugetlb.c: In function 'hugetlb_reserve_pages':
include/linux/build_bug.h:36:33: error: void value not ignored as it ought to be
 #define BUILD_BUG_ON_INVALID(e) ((void)(sizeof((__force long)(e))))
                                 ^
include/linux/mmdebug.h:52:34: note: in expansion of macro 'BUILD_BUG_ON_INVALID'
 #define VM_WARN(cond, format...) BUILD_BUG_ON_INVALID(cond)
                                  ^~~~~~~~~~~~~~~~~~~~
mm/hugetlb.c:4379:6: note: in expansion of macro 'VM_WARN'
  if (VM_WARN(from > to, "%s called with a negative range\n", __func__))
      ^~~~~~~
scripts/Makefile.build:324: recipe for target 'mm/hugetlb.o' failed

Caused by commit

  df9b0bfadaa3 ("hugetlbfs-check-for-pgoff-value-overflow-v3-fix")

I have applied the following patch (a partial revert of the above):

From: Stephen Rothwell <[email-masked]>
Date: Wed, 14 Mar 2018 16:38:50 +1100
Subject: [PATCH] pertially revert
 "hugetlbfs-check-for-pgoff-value-overflow-v3-fix"

Signed-off-by: Stephen Rothwell <[email-masked]>
---
 mm/hugetlb.c | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/mm/hugetlb.c b/mm/hugetlb.c
index 3b31dcfb7621..218679138255 100644
--- a/mm/hugetlb.c
+++ b/mm/hugetlb.c
@@ -4376,8 +4376,11 @@ int hugetlb_reserve_pages(struct inode *inode,
 	struct resv_map *resv_map;
 	long gbl_reserve;
 
-	if (VM_WARN(from > to, "%s called with a negative range\n", __func__))
+	/* This should never happen */
+	if (from > to) {
+		VM_WARN(1, "%s called with a negative range\n", __func__);
 		return -EINVAL;
+	}
 
 	/*
 	 * Only apply hugepage reservation if asked. At fault time, an
-- 
2.16.1

-- 
Cheers,
Stephen Rothwell