syscall_wrappers: add pivot_root()

src/lxc/conf.c

@@ -74,6 +74,7 @@
 #include "start.h"
 #include "storage.h"
 #include "storage/overlay.h"
+#include "syscall_wrappers.h"
 #include "terminal.h"
 #include "utils.h"
 
@@ -124,21 +125,6 @@ thread_local struct lxc_conf *current_config;
 struct lxc_conf *current_config;
 #endif
 
-/* Define pivot_root() if missing from the C library */
-#ifndef HAVE_PIVOT_ROOT
-static int pivot_root(const char *new_root, const char *put_old)
-{
-#ifdef __NR_pivot_root
-	return syscall(__NR_pivot_root, new_root, put_old);
-#else
-	errno = ENOSYS;
-	return -1;
-#endif
-}
-#else
-extern int pivot_root(const char *new_root, const char *put_old);
-#endif
-
 char *lxchook_names[NUM_LXC_HOOKS] = {
 	"pre-start",
 	"pre-mount",

src/lxc/syscall_wrappers.h

@@ -48,4 +48,18 @@ static inline long __keyctl(int cmd, unsigned long arg2, unsigned long arg3,
 #define keyctl __keyctl
 #endif
 
+#if !HAVE_PIVOT_ROOT
+static int pivot_root(const char *new_root, const char *put_old)
+{
+#ifdef __NR_pivot_root
+	return syscall(__NR_pivot_root, new_root, put_old);
+#else
+	errno = ENOSYS;
+	return -1;
+#endif
+}
+#else
+extern int pivot_root(const char *new_root, const char *put_old);
+#endif
+
 #endif /* __LXC_SYSCALL_WRAPPER_H */