diff options
| author | Eric W. Biederman <ebiederm@xmission.com> | 2007-10-18 12:05:58 +0200 |
|---|---|---|
| committer | Linus Torvalds <torvalds@woody.linux-foundation.org> | 2007-10-18 23:37:23 +0200 |
| commit | 7058cb02ddab4bce70a46e519804fccb7ac0a060 (patch) | |
| tree | c0d3bfc395472a2a8c9098227739892a9090b3a0 /Documentation | |
| parent | sysctl: for irda update sysctl_checks list of binary paths (diff) | |
| download | linux-7058cb02ddab4bce70a46e519804fccb7ac0a060.tar.xz linux-7058cb02ddab4bce70a46e519804fccb7ac0a060.zip | |
sysctl: deprecate sys_sysctl in a user space visible fashion.
After adding checking to register_sysctl_table and finding a whole new set
of bugs. Missed by countless code reviews and testers I have finally lost
patience with the binary sysctl interface.
The binary sysctl interface has been sort of deprecated for years and
finding a user space program that uses the syscall is more difficult then
finding a needle in a haystack. Problems continue to crop up, with the in
kernel implementation. So since supporting something that no one uses is
silly, deprecate sys_sysctl with a sufficient grace period and notice that
the handful of user space applications that care can be fixed or replaced.
The /proc/sys sysctl interface that people use will continue to be
supported indefinitely.
This patch moves the tested warning about sysctls from the path where
sys_sysctl to a separate path called from both implementations of
sys_sysctl, and it adds a proper entry into
Documentation/feature-removal-schedule.
Allowing us to revisit this in a couple years time and actually kill
sys_sysctl.
[lethal@linux-sh.org: sysctl: Fix syscall disabled build]
Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
Signed-off-by: Paul Mundt <lethal@linux-sh.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'Documentation')
| -rw-r--r-- | Documentation/feature-removal-schedule.txt | 35 |
1 files changed, 35 insertions, 0 deletions
diff --git a/Documentation/feature-removal-schedule.txt b/Documentation/feature-removal-schedule.txt index 280ec06573e6..5b25162cd9a4 100644 --- a/Documentation/feature-removal-schedule.txt +++ b/Documentation/feature-removal-schedule.txt @@ -82,6 +82,41 @@ Who: Dominik Brodowski <linux@brodo.de> --------------------------- +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: a.out interpreter support for ELF executables When: 2.6.25 Files: fs/binfmt_elf.c |