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Date:   Fri, 22 May 2020 15:13:55 +0200
From:   Christian Brauner <christian.brauner@ubuntu.com>
To:     Joel Fernandes <joel@joelfernandes.org>
Cc:     LKML <linux-kernel@vger.kernel.org>,
        Matthew Blecker <matthewb@google.com>,
        Jesse Barnes <jsbarnes@google.com>,
        Mike Frysinger <vapier@google.com>,
        Christian Brauner <christian@brauner.io>,
        Vineeth Remanan Pillai <vpillai@digitalocean.com>,
        vineethrp@gmail.com, Peter Zijlstra <peterz@infradead.org>,
        stable <stable@vger.kernel.org>,
        Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Subject: Re: [PATCH RFC] sched/headers: Fix sched_setattr userspace
 compilation issues
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On Thu, May 21, 2020 at 11:55:21AM -0400, Joel Fernandes wrote:
> On Thu, May 21, 2020 at 11:53 AM Joel Fernandes (Google)
> <joel@joelfernandes.org> wrote:
> >
> > On a modern Linux distro, compiling the following program fails:
> >  #include<stdlib.h>
> >  #include<stdint.h>
> >  #include<pthread.h>
> >  #include<linux/sched/types.h>
> >
> >  void main() {
> >          struct sched_attr sa;
> >
> >          return;
> >  }
> >
> > with:
> > /usr/include/linux/sched/types.h:8:8: \
> >                         error: redefinition of ‘struct sched_param’
> >     8 | struct sched_param {
> >       |        ^~~~~~~~~~~
> > In file included from /usr/include/x86_64-linux-gnu/bits/sched.h:74,
> >                  from /usr/include/sched.h:43,
> >                  from /usr/include/pthread.h:23,
> >                  from /tmp/s.c:4:
> > /usr/include/x86_64-linux-gnu/bits/types/struct_sched_param.h:23:8:
> > note: originally defined here
> >    23 | struct sched_param
> >       |        ^~~~~~~~~~~
> >
> > This is also causing a problem on using sched_attr Chrome. The issue is
> > sched_param is already provided by glibc.
> >
> > Guard the kernel's UAPI definition of sched_param with __KERNEL__ so
> > that userspace can compile.
> >
> > Signed-off-by: Joel Fernandes (Google) <joel@joelfernandes.org>
> 
> If it is more preferable, another option is to move sched_param to
> include/linux/sched/types.h

Might it be worth Ccing libc-alpha here? Seems like one of those classic
header conflicts.

Christian