Re: [PATCH] uapi glibc compat: fix cases where glibc net/if.h is included before linux/if.h

From	David Miller <davem@davemloft.net>
Newsgroups	linux.kernel
Subject	Re: [PATCH] uapi glibc compat: fix cases where glibc net/if.h is included before linux/if.h
Date	2016-02-26 17:30 +0100
Message-ID	<r6trb-5Z1-9@gated-at.bofh.it> (permalink)
References	<qZyci-7ez-5@gated-at.bofh.it> <r3cwx-8pl-11@gated-at.bofh.it> <r6l0D-8aG-21@gated-at.bofh.it>
Organization	linux.* mail to news gateway

Show all headers | View raw

From: Mikko Rapeli <mikko.rapeli@iki.fi>
Date: Fri, 26 Feb 2016 09:25:13 +0200

> (Adding libc-alpha list, review of https://lkml.org/lkml/2016/2/7/89 )
> 
> On Wed, Feb 17, 2016 at 10:46:20AM -0500, David Miller wrote:
>> From: Mikko Rapeli <mikko.rapeli@iki.fi>
>> Date: Sun,  7 Feb 2016 16:03:21 +0200
>> 
>> > @@ -68,6 +72,8 @@
>> >   * @IFF_ECHO: echo sent packets. Volatile.
>> >   */
>> >  enum net_device_flags {
>> > +/* for compatibility with glibc net/if.h */
>> > +#if __UAPI_DEF_IF_NET_DEVICE_FLAGS
>> >  	IFF_UP				= 1<<0,  /* sysfs */
>> >  	IFF_BROADCAST			= 1<<1,  /* volatile */
>> >  	IFF_DEBUG			= 1<<2,  /* sysfs */
>> > @@ -84,11 +90,14 @@ enum net_device_flags {
>> >  	IFF_PORTSEL			= 1<<13, /* sysfs */
>> >  	IFF_AUTOMEDIA			= 1<<14, /* sysfs */
>> >  	IFF_DYNAMIC			= 1<<15, /* sysfs */
>> > +#endif /* __UAPI_DEF_IF_NET_DEVICE_FLAGS */
>> >  	IFF_LOWER_UP			= 1<<16, /* volatile */
>> >  	IFF_DORMANT			= 1<<17, /* volatile */
>> >  	IFF_ECHO			= 1<<18, /* volatile */
>> >  };
>> 
>> This is going to get messy is IFF_LOWER_UP, IFF_DORMANT, and IFF_ECHO
>> get added the the glibc header.  Why not just handle it now with
>> another __UAPI_DEF_FOO guard so that the additions to net/if.h can
>> deal with this case too.
> 
> Do you mean that the enum should be protected with a single guard or
> should I have one guard for current conflicts and one for the future
> if glibc headers include IFF_LOWER_UP and others?

I'm ambivalent about the mechanism, and I'm more concerned about covering
those three values in your change rather than eliding them.

Back to linux.kernel | Previous | Next — Previous in thread | Find similar | Unroll thread

Thread

Re: [PATCH] uapi glibc compat: fix cases where glibc net/if.h is  included before linux/if.h Mikko Rapeli <mikko.rapeli@iki.fi> - 2016-02-26 08:30 +0100
  Re: [PATCH] uapi glibc compat: fix cases where glibc net/if.h is  included before linux/if.h David Miller <davem@davemloft.net> - 2016-02-26 17:30 +0100

csiph-web