From: SeongJae Park <sjpark@xxxxxxxxx> Commit 49eeab03fa0a ("userfaultfd: support minor fault handling for shmem") introduced shmem_mcopy_atomic_pte(). The function is declared in 'userfaultfd_k.h' when 'CONFIG_USERFAULTFD' is defined, and defined as 'BUG()' if the config is unset. However, the definition of the function in 'shmem.c' is not protected by the '#ifdef' macro. As a result, the build fails when the config is not set. This commit fixes the problem. Fixes: 49eeab03fa0a ("userfaultfd: support minor fault handling for shmem") Signed-off-by: SeongJae Park <sjpark@xxxxxxxxx> --- Changes from v1 - Remove unnecessary internal code review URL --- mm/shmem.c | 2 ++ 1 file changed, 2 insertions(+) diff --git a/mm/shmem.c b/mm/shmem.c index 547df2b766f7..c0d3abefeb3f 100644 --- a/mm/shmem.c +++ b/mm/shmem.c @@ -2359,6 +2359,7 @@ static struct inode *shmem_get_inode(struct super_block *sb, const struct inode return inode; } +#ifdef CONFIG_USERFAULTFD int shmem_mcopy_atomic_pte(struct mm_struct *dst_mm, pmd_t *dst_pmd, struct vm_area_struct *dst_vma, unsigned long dst_addr, unsigned long src_addr, @@ -2492,6 +2493,7 @@ int shmem_mcopy_atomic_pte(struct mm_struct *dst_mm, pmd_t *dst_pmd, shmem_inode_unacct_blocks(inode, 1); goto out; } +#endif #ifdef CONFIG_TMPFS static const struct inode_operations shmem_symlink_inode_operations; -- 2.17.1 Amazon Development Center Germany GmbH Krausenstr. 38 10117 Berlin Geschaeftsfuehrung: Christian Schlaeger, Jonathan Weiss Eingetragen am Amtsgericht Charlottenburg unter HRB 149173 B Sitz: Berlin Ust-ID: DE 289 237 879