sysctl: allow embedded targets to disable sysctl_check.c

Disable sysctl_check.c for embedded targets. This saves about about 11 kB
in .text and another 11 kB in .data on a PXA255 embedded platform.

Signed-off-by: Holger Schurig <hs4233@mail.mn-solutions.de>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

3 files changed, 20 insertions, 3 deletions

diff --git a/init/Kconfig b/init/Kconfig
index 98fa96eac415..3e7b257fc05f 100644
--- a/init/Kconfig
+++ b/init/Kconfig
@@ -550,6 +550,17 @@ config SYSCTL_SYSCALL
 
           If unsure say Y here.
 
+config SYSCTL_SYSCALL_CHECK
+        bool "Sysctl checks" if EMBEDDED
+        depends on SYSCTL_SYSCALL
+        default y
+        ---help---
+          sys_sysctl uses binary paths that have been found challenging
+          to properly maintain and use. This enables checks that help
+          you to keep things correct.
+
+          If unsure say Y here.
+
 config KALLSYMS
          bool "Load all symbols for debugging/ksymoops" if EMBEDDED
          default y
diff --git a/kernel/Makefile b/kernel/Makefile
index 6c5f081132a4..188c43223f52 100644
--- a/kernel/Makefile
+++ b/kernel/Makefile
@@ -11,7 +11,7 @@ obj-y     = sched.o fork.o exec_domain.o panic.o printk.o profile.o \
             hrtimer.o rwsem.o nsproxy.o srcu.o semaphore.o \
             notifier.o ksysfs.o pm_qos_params.o
 
-obj-$(CONFIG_SYSCTL) += sysctl_check.o
+obj-$(CONFIG_SYSCTL_SYSCALL_CHECK) += sysctl_check.o
 obj-$(CONFIG_STACKTRACE) += stacktrace.o
 obj-y += time/
 obj-$(CONFIG_DEBUG_MUTEXES) += mutex-debug.o
diff --git a/kernel/sysctl.c b/kernel/sysctl.c
index 0a1d2733cf41..1cdfe942d160 100644
--- a/kernel/sysctl.c
+++ b/kernel/sysctl.c
@@ -1592,9 +1592,13 @@ static void sysctl_set_parent(struct ctl_table *parent, struct ctl_table *table)
 
 static __init int sysctl_init(void)
 {
-        int err;
         sysctl_set_parent(NULL, root_table);
-        err = sysctl_check_table(current->nsproxy, root_table);
+#ifdef CONFIG_SYSCTL_SYSCALL_CHECK
+        {
+                int err;
+                err = sysctl_check_table(current->nsproxy, root_table);
+        }
+#endif
         return 0;
 }
 
@@ -1721,10 +1725,12 @@ struct ctl_table_header *__register_sysctl_paths(
         header->unregistering = NULL;
         header->root = root;
         sysctl_set_parent(NULL, header->ctl_table);
+#ifdef CONFIG_SYSCTL_SYSCALL_CHECK
         if (sysctl_check_table(namespaces, header->ctl_table)) {
                 kfree(header);
                 return NULL;
         }
+#endif
         spin_lock(&sysctl_lock);
         header_list = lookup_header_list(root, namespaces);
         list_add_tail(&header->ctl_entry, header_list);