Re: [PATCH -tip] x86: headers - fix export private data to userspace

H. Peter Anvin
2009-01-13T19:03:42Z

Cyrill Gorcunov wrote:
> | > |
> | > | You can introduce symbols into the general namespace if *and only if*
> | > | they are in a header file that is invoked directly by the user. In
> | > | other words, such a header file is unusable by libc, but setup.h doesn't
> | > | contain anything needed by libc in the first place.
> | > |
> | > | -hpa
> | > |
> | >
> | > So we could just fence it by __KERNEL__?
> | >
> |
> | We might, as userspace shouldn't need COMMAND_LINE_SIZE anyway (see
> | other post), but I'm rather confused as how you got that from what I
> | wrote above.
> |
>
> The thing is that kernel headers are not only touched by libc.
> Someone could write a program and include setup.h there.
> Or I translated you wrong :)
>

My whole point was that there are classes of symbols which may be
legitimately used by userspace *applications*, but not by libc. Those
can live in the general namespace since they are included by explicit
user command.

-hpa

--
H. Peter Anvin, Intel Open Source Technology Center
I work for Intel. I don't speak on their behalf.