# \[PATCH 17/20\] x86: usercopy: include arch\_wb\_cache\_pmem declaration

- From: Arnd Bergmann \<arnd@kernel.org\>
- Date: 2023-05-16 19:38:38 
- List: linux-trace-kernel
- Page: https://ratatoskr.run/linux-trace-kernel/2023/05/2199812
- Thread: https://ratatoskr.run/linux-trace-kernel/2023/05/2199796/t.md

```text
From: Arnd Bergmann <arnd@arndb.de>

arch_wb_cache_pmem() is declared in a global header but defined by
the architecture. On x86, the implementation needs to include the header
to avoid this warning:

arch/x86/lib/usercopy_64.c:39:6: error: no previous prototype for 'arch_wb_cache_pmem' [-Werror=missing-prototypes]

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
---
 arch/x86/lib/usercopy_64.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/arch/x86/lib/usercopy_64.c b/arch/x86/lib/usercopy_64.c
index 003d90138e20..e9251b89a9e9 100644
--- a/arch/x86/lib/usercopy_64.c
+++ b/arch/x86/lib/usercopy_64.c
@@ -9,6 +9,7 @@
 #include <linux/export.h>
 #include <linux/uaccess.h>
 #include <linux/highmem.h>
+#include <linux/libnvdimm.h>
 
 /*
  * Zero Userspace
-- 
2.39.2

```