/* this is needed for the proc_dointvec_minmax for [fs_]overflow UID and GID */
 static const int maxolduid = 65535;
-static const int minolduid;
+/* minolduid is SYSCTL_ZERO */
 
 static const int ngroups_max = NGROUPS_MAX;
 static const int cap_last_cap = CAP_LAST_CAP;
 #endif
 
 #ifdef CONFIG_COMPACTION
-static const int min_extfrag_threshold;
+/* min_extfrag_threshold is SYSCTL_ZERO */;
 static const int max_extfrag_threshold = 1000;
 #endif
 
                .maxlen         = sizeof(int),
                .mode           = 0644,
                .proc_handler   = proc_dointvec_minmax,
-               .extra1         = (void *)&minolduid,
+               .extra1         = SYSCTL_ZERO,
                .extra2         = (void *)&maxolduid,
        },
        {
                .maxlen         = sizeof(int),
                .mode           = 0644,
                .proc_handler   = proc_dointvec_minmax,
-               .extra1         = (void *)&minolduid,
+               .extra1         = SYSCTL_ZERO,
                .extra2         = (void *)&maxolduid,
        },
 #ifdef CONFIG_S390
                .maxlen         = sizeof(int),
                .mode           = 0644,
                .proc_handler   = proc_dointvec_minmax,
-               .extra1         = (void *)&min_extfrag_threshold,
+               .extra1         = SYSCTL_ZERO,
                .extra2         = (void *)&max_extfrag_threshold,
        },
        {
                .maxlen         = sizeof(int),
                .mode           = 0644,
                .proc_handler   = proc_dointvec_minmax,
-               .extra1         = (void *)&minolduid,
+               .extra1         = SYSCTL_ZERO,
                .extra2         = (void *)&maxolduid,
        },
        {
                .maxlen         = sizeof(int),
                .mode           = 0644,
                .proc_handler   = proc_dointvec_minmax,
-               .extra1         = (void *)&minolduid,
+               .extra1         = SYSCTL_ZERO,
                .extra2         = (void *)&maxolduid,
        },
 #ifdef CONFIG_FILE_LOCKING