sysctl: make CONFIG_SYSCTL_SYSCALL default to n

When I tried to send a patch to remove it, Andi told me we still need to
keep compabitlies for old libc, so we can't remove this completely.  Then
just make it default to n and remove the doc from
feature-removal-schedule.txt.

Signed-off-by: WANG Cong <amwang@redhat.com>
Cc: Eric Biederman <ebiederm@xmission.com>
Cc: Andi Kleen <andi@firstfloor.org>
Cc: Alexey Dobriyan <adobriyan@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

2 files changed, 2 insertions, 37 deletions

diff --git a/Documentation/feature-removal-schedule.txt b/Documentation/feature-removal-schedule.txt
index 7c799fc5b88e..3d849122b5b1 100644
--- a/Documentation/feature-removal-schedule.txt
+++ b/Documentation/feature-removal-schedule.txt
@@ -133,41 +133,6 @@ Who:	Pavel Machek <pavel@ucw.cz>
 
 ---------------------------
 
-What:   sys_sysctl
-When:   September 2010
-Option: CONFIG_SYSCTL_SYSCALL
-Why:    The same information is available in a more convenient from
-        /proc/sys, and none of the sysctl variables appear to be
-        important performance wise.
-
-        Binary sysctls are a long standing source of subtle kernel
-        bugs and security issues.
-
-        When I looked several months ago all I could find after
-        searching several distributions were 5 user space programs and
-        glibc (which falls back to /proc/sys) using this syscall.
-
-        The man page for sysctl(2) documents it as unusable for user
-        space programs.
-
-        sysctl(2) is not generally ABI compatible to a 32bit user
-        space application on a 64bit and a 32bit kernel.
-
-        For the last several months the policy has been no new binary
-        sysctls and no one has put forward an argument to use them.
-
-        Binary sysctls issues seem to keep happening appearing so
-        properly deprecating them (with a warning to user space) and a
-        2 year grace warning period will mean eventually we can kill
-        them and end the pain.
-
-        In the mean time individual binary sysctls can be dealt with
-        in a piecewise fashion.
-
-Who:    Eric Biederman <ebiederm@xmission.com>
-
----------------------------
-
 What:   /proc/<pid>/oom_adj
 When:   August 2012
 Why:    /proc/<pid>/oom_adj allows userspace to influence the oom killer's
diff --git a/init/Kconfig b/init/Kconfig
index 31ba0fd0f36b..43298f9810fb 100644
--- a/init/Kconfig
+++ b/init/Kconfig
@@ -947,7 +947,7 @@ config UID16
 config SYSCTL_SYSCALL
         bool "Sysctl syscall support" if EXPERT
         depends on PROC_SYSCTL
-        default y
+        default n
         select SYSCTL
         ---help---
           sys_sysctl uses binary paths that have been found challenging
@@ -959,7 +959,7 @@ config SYSCTL_SYSCALL
           trying to save some space it is probably safe to disable this,
           making your kernel marginally smaller.
 
-          If unsure say Y here.
+          If unsure say N here.
 
 config KALLSYMS
          bool "Load all symbols for debugging/ksymoops" if EXPERT