[PATCH 14/14] time_namespace: always provide arch_get_vdso_data() prototype for vdso

Arnd Bergmann arnd at kernel.org
Wed May 17 23:11:02 AEST 2023

From: Arnd Bergmann <arnd at arndb.de>

The arch_get_vdso_data() function is defined separately on each architecture,
but only called when CONFIG_TIME_NS is set. If the definition is a global
function, this causes a W=1 warning without TIME_NS:

arch/x86/entry/vdso/vma.c:35:19: error: no previous prototype for 'arch_get_vdso_data' [-Werror=missing-prototypes]

Move the prototype out of the #ifdef block to reliably turn off that

Signed-off-by: Arnd Bergmann <arnd at arndb.de>
 include/linux/time_namespace.h | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/include/linux/time_namespace.h b/include/linux/time_namespace.h
index bb9d3f5542f8..03d9c5ac01d1 100644
--- a/include/linux/time_namespace.h
+++ b/include/linux/time_namespace.h
@@ -44,7 +44,6 @@ struct time_namespace *copy_time_ns(unsigned long flags,
 				    struct time_namespace *old_ns);
 void free_time_ns(struct time_namespace *ns);
 void timens_on_fork(struct nsproxy *nsproxy, struct task_struct *tsk);
-struct vdso_data *arch_get_vdso_data(void *vvar_page);
 struct page *find_timens_vvar_page(struct vm_area_struct *vma);
 static inline void put_time_ns(struct time_namespace *ns)
@@ -163,4 +162,6 @@ static inline ktime_t timens_ktime_to_host(clockid_t clockid, ktime_t tim)
+struct vdso_data *arch_get_vdso_data(void *vvar_page);
 #endif /* _LINUX_TIMENS_H */

More information about the Linuxppc-dev mailing list