[PATCH] mm/memory.c: Mark wp_huge_pmd() inline to prevent build failure

From: Geert Uytterhoeven
Date: Sun Dec 03 2017 - 16:12:00 EST


With gcc 4.1.2:

mm/memory.o: In function `wp_huge_pmd':
memory.c:(.text+0x9b4): undefined reference to `do_huge_pmd_wp_page'

Interestingly, wp_huge_pmd() is emitted in the assembler output, but
never called.

Apparently replacing the call to pmd_write() in __handle_mm_fault() by a
call to the more complex pmd_access_permitted() reduced the ability of
the compiler to remove unused code.

Fix this by marking wp_huge_pmd() inline, like was done in commit
91a90140f9987101 ("mm/memory.c: mark create_huge_pmd() inline to prevent
build failure") for a similar problem.

Fixes: c7da82b894e9eef6 ("mm: replace pmd_write with pmd_access_permitted in fault + gup paths")
Signed-off-by: Geert Uytterhoeven <geert@xxxxxxxxxxxxxx>
---
mm/memory.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/mm/memory.c b/mm/memory.c
index 5eb3d2524bdc2823..f4d52847ca07a414 100644
--- a/mm/memory.c
+++ b/mm/memory.c
@@ -3831,7 +3831,7 @@ static inline int create_huge_pmd(struct vm_fault *vmf)
return VM_FAULT_FALLBACK;
}

-static int wp_huge_pmd(struct vm_fault *vmf, pmd_t orig_pmd)
+static inline int wp_huge_pmd(struct vm_fault *vmf, pmd_t orig_pmd)
{
if (vma_is_anonymous(vmf->vma))
return do_huge_pmd_wp_page(vmf, orig_pmd);
--
2.7.4