If CONFIG_TRANSPARENT_HUGE_PAGECACHE=n, HPAGE_PMD_NR evaluates to
BUILD_BUG_ON(), and may cause (e.g. with gcc 4.12):
mm/built-in.o: In function `shmem_alloc_hugepage':
shmem.c:(.text+0x17570): undefined reference to `__compiletime_assert_1365'
To fix this, move the assignment to hindex after the check for huge
pages support.
Fixes: 800d8c63b2e989c2 ("shmem: add huge pages support")
Signed-off-by: Geert Uytterhoeven <geert@xxxxxxxxxxxxxx>
---
mm/shmem.c | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)
diff --git a/mm/shmem.c b/mm/shmem.c
index 2ac19a61d5655b82..7f7748a0f9e1f738 100644
--- a/mm/shmem.c
+++ b/mm/shmem.c
@@ -1362,13 +1362,14 @@ static struct page *shmem_alloc_hugepage(gfp_t gfp,
struct vm_area_struct pvma;
struct inode *inode = &info->vfs_inode;
struct address_space *mapping = inode->i_mapping;
- pgoff_t idx, hindex = round_down(index, HPAGE_PMD_NR);
+ pgoff_t idx, hindex;
void __rcu **results;
struct page *page;
if (!IS_ENABLED(CONFIG_TRANSPARENT_HUGE_PAGECACHE))
return NULL;
+ hindex = round_down(index, HPAGE_PMD_NR);
rcu_read_lock();
if (radix_tree_gang_lookup_slot(&mapping->page_tree, &results, &idx,
hindex, 1) && idx < hindex + HPAGE_PMD_NR) {
--
1.9.1
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