Re: PATCH: Add x32 dummy sysctl

[ebiederm at xmission dot com (Eric W. Biederman)]

"Joseph S. Myers" <joseph@codesourcery.com> writes:

> On Thu, 17 May 2012, Roland McGrath wrote:
>
>> Since according to the kernel folks this call is thoroughly undesired on
>> every machine now, we should also add __attribute__ ((deprecated)) to the
>> declaration.  We need a sys/cdefs.h macro for that.  Hmm, we already have
>> __warndecl so we might as well just use that unless we really think that
>> someone cares about using -Wno-deprecated-declarations.
>
> I admit to being a bit confused about the exact story of sysctl 
> deprecation - I was told in bug 3063 that the syscall had been removed, 
> then that the removal was reverted so that it was no longer necessary to 
> stop ARM glibc from using it internally.

There is no real maintenance of the binary sysctl syscall code, and it
is disabled by default when building the kernel.  No one has really
cared about the code for as long as I can remember.

Currently the code is in a state where it can survive without
maintenance for a while, but the kernel unconditionally warns when a
sysctl is used.  So the plan is to remove the sysctl syscall when we are
bored some day or we realize tha the code in the kernel has bit-rotted
to the point where it does not work, and we happen to notice.

>From what little I know the code in ARM glibc that is used so little I
expect most ARM installations would not even notice if we removed
support from the kernel.

I went the extra mile once and tried to fix ARM glibc the process was
much to cumbersome and no one else seemed to care.  So at this point I
don't care.  I'm not bored enough to write the patch to remove the
kernel support either so you have a few days before the code bit-rotted
to the point of unusability.

Eric