Re: Recent changes to sysctl.h breaks glibc

[ebiederm@xmission.com (Eric W. Biederman)]

Valdis.Kletnieks@vt.edu writes:

> On Mon, 19 May 2003 17:55:06 MDT, Eric W. Biederman said:
> > If things must be maintained in concert it is a bug.  
> > 
> > With a fixed ABI people take advantage of new features as they
> > care for them.  And in general to use new features requires new code.
> 
> And if the kernel headers aren't maintained in concert with the kernel,
> new userspace code can't reach the new features.
> 
> Therefor, by your definition, the current situation is a bug.

Yes, glibc uses kernel headers.

> Try compiling code that uses futexes on a system that has a kernel that
> supports them, but kernel-headers that haven't been upgraded to mention them.
> The kernel has the new code, the userspace has the new code, but gcc will
> turn around and whinge about the new code because there's a piece missing in
> between.  So people *CANT* take advantage of the new features (unless they
> do something silly like drag their own foo.h file around where it can get
> out of sync with reality).

Or the build against a library that does that.  There are not that
many libraries.

For a lot of system calls it is actively dangerous to assume dev_t ==
__kernel_dev_t.  As glibc does some cute things in there.

Eric