4.18-stable review patch. If anyone has any objections, please let me know. ------------------ From: Arnd Bergmann <arnd@xxxxxxxx> [ Upstream commit a2036a1ef2ee91acab01a0ae4a534070691a42ec ] Without CONFIG_MMU, we get a build warning: fs/proc/vmcore.c:228:12: error: 'vmcoredd_mmap_dumps' defined but not used [-Werror=unused-function] static int vmcoredd_mmap_dumps(struct vm_area_struct *vma, unsigned long dst, The function is only referenced from an #ifdef'ed caller, so this uses the same #ifdef around it. Link: http://lkml.kernel.org/r/20180525213526.2117790-1-arnd@xxxxxxxx Fixes: 7efe48df8a3d ("vmcore: append device dumps to vmcore as elf notes") Signed-off-by: Arnd Bergmann <arnd@xxxxxxxx> Cc: Ganesh Goudar <ganeshgr@xxxxxxxxxxx> Cc: "David S. Miller" <davem@xxxxxxxxxxxxx> Cc: Rahul Lakkireddy <rahul.lakkireddy@xxxxxxxxxxx> Cc: Alexey Dobriyan <adobriyan@xxxxxxxxx> Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> Signed-off-by: Linus Torvalds <torvalds@xxxxxxxxxxxxxxxxxxxx> Signed-off-by: Sasha Levin <alexander.levin@xxxxxxxxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- fs/proc/vmcore.c | 2 ++ 1 file changed, 2 insertions(+) --- a/fs/proc/vmcore.c +++ b/fs/proc/vmcore.c @@ -225,6 +225,7 @@ out_unlock: return ret; } +#ifdef CONFIG_MMU static int vmcoredd_mmap_dumps(struct vm_area_struct *vma, unsigned long dst, u64 start, size_t size) { @@ -259,6 +260,7 @@ out_unlock: mutex_unlock(&vmcoredd_mutex); return ret; } +#endif /* CONFIG_MMU */ #endif /* CONFIG_PROC_VMCORE_DEVICE_DUMP */ /* Read from the ELF header and then the crash dump. On error, negative value is