Re: xattr.h wonkiness
Quoting Carlos O'Donell (carlos@systemhalted.org):
> On Fri, Mar 7, 2014 at 12:31 AM, Serge Hallyn <serge.hallyn@ubuntu.com> wrote:
> > Quoting Carlos O'Donell (carlos@systemhalted.org):
> >> On Thu, Mar 6, 2014 at 6:06 PM, Serge Hallyn <serge.hallyn@ubuntu.com> wrote:
> >> > Quoting Carlos O'Donell (carlos@systemhalted.org):
> >> >> On Fri, Feb 21, 2014 at 6:42 PM, Serge Hallyn <serge.hallyn@ubuntu.com> wrote:
> >> >> > Hi, would a simple patchl ike this to misc/sys/xattr.h be
> >> >> > acceptable? This showed up in a failure to build (of at least
> >> >> > qemu, and aiui lots of other pkgs) after merging a new libcap2
> >> >> > where sys/capability.h #included linux/xattr.h. It's being
> >> >> > worked around by patching libcap2 to #include sys/xattr.h
> >> >> > first, but presumably this will cause other breakages.
> >> >>
> >> >> Please follow the accepted practice for fixing coordination between
> >> >> userspace and Linux kernel headers.
> >> >>
> >> >> Upstream glibc and the Linux kernel have already worked out a
> >> >> mechanical solution to this problem, and we need people to work out
> >> >> the patches and post them upstream.
> >> >>
> >> >> The solution is to coordinate the conflicting headers following this template:
> >> >> https://sourceware.org/glibc/wiki/Synchronizing_Headers
> >> >
> >> > Thanks for the information. I tested the two patches at
> >> > http://people.canonical.com/~serge/xattr-kernel-libc-fix/ and they
> >> > seem to do the right thing. I'll send them out if they look ok.
> >>
> >> Let me warn you that the glibc patch won't get accepted as-is.
> >>
> >> You are adding a #ifdef for a Linux-specific define in OS-agnostic code.
> >>
> >> Look at: https://sourceware.org/ml/libc-alpha/2013-08/msg00209.html
> >>
> >> See how we adjust a Linux-specific header to define an OS-agnostic
> >> variable to use in the OS-agnostic code e.g. __USE_FOO.
> >
> > There isn't currently a bits/xattr.h file. Would it be preferred that
> > I create one, or that I just set __USE_KERNEL_XATTR_DEFS in the
> > linux kernel header?
>
> I don't know, you'll have to take a stab at an implementation and see
> what upstream likes.
>
> I haven't reviewed this thoroughly so I can't comment yet.
Ah ok, thanks. I'll just start with the kernel patch then, with the
define in there.
thanks,
-serge
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