From: Mike Frysinger <vapier@gentoo•org>
To: David Miller <davem@davemloft•net>
Cc: libc-alpha@sourceware•org, bhutchings@solarflare•com,
yoshfuji@linux-ipv6•org, amwang@redhat•com, tmb@mageia•org,
eblake@redhat•com, netdev@vger•kernel.org,
linux-kernel@vger•kernel.org, libvirt-list@redhat•com,
tgraf@suug•ch, schwab@suse•de, carlos@systemhalted•org
Subject: Re: Redefinition of struct in6_addr in <netinet/in.h> and <linux/in6.h>
Date: Wed, 16 Jan 2013 14:29:30 -0500 [thread overview]
Message-ID: <201301161429.33814.vapier@gentoo.org> (raw)
In-Reply-To: <20130116.135744.697469565804508454.davem@davemloft.net>
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On Wednesday 16 January 2013 13:57:44 David Miller wrote:
> From: Mike Frysinger <vapier@gentoo•org>
> > certainly true, but the current expectation is that you don't mix your
> > ABIs. if you're programming with the C library API, then use the C
> > library headers. if you're banging directly on the kernel, then use the
> > kernel headers. not saying it's a perfect solution, but it works for
> > the vast majority of use cases.
>
> This isn't how real life works.
>
> GLIBC itself brings in some of the kernel headers, as do various library
> headers for libraries other than glibc.
>
> So you can get these conflicting headers included indirectly, and it is
> of no fault of any of the various parties involved.
the headers glibc includes tend to be pretty stand alone specifically so that
it doesn't matter
> We have to make them work when included at the same time somehow, and
> this is totally unavoidable.
"them" is vague. saying that every kernel header has to be usable in the same
compilation unit as every C library header regardless of order is unrealistic
(at least it is today). there are cases where they define the same structure
different because the structure as the C library expects is different from what
the kernel syscall expects. you could avoid that on the kernel side by giving
them all prefixes (like __kernel_), but that didn't seem entirely palpable to
the kernel folks. i couldn't even get them to remove crap that breaks non-
glibc C libraries (e.g. uapi/linux/stat.h -- looks like someone inadvertently
fixed uapi/linux/socket.h finally).
for many networking headers, the C library will provide enums & defines while
the kernel only provides enums. including the kernel after the C library one
leads to parsing errors as the defines expand in the enum and kill it. like
linux/in.h and netinet/in.h and IPPROTO_*.
-mike
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next prev parent reply other threads:[~2013-01-16 19:29 UTC|newest]
Thread overview: 45+ messages / expand[flat|nested] mbox.gz Atom feed top
2013-01-13 18:38 if_bridge.h: include in6.h for struct in6_addr use Thomas Backlund
2013-01-13 20:05 ` Thomas Backlund
2013-01-14 23:57 ` [libvirt] " Eric Blake
2013-01-15 10:03 ` [libvirt] the patch "bridge: export multicast database via netlink" broke kernel 3.8 uapi (was: Re: if_bridge.h: include in6.h for struct in6_addr use) Thomas Backlund
2013-01-15 10:11 ` the patch "bridge: export multicast database via netlink" broke kernel 3.8 uapi (was: Re: [libvirt] " Cong Wang
2013-01-15 10:55 ` the patch "bridge: export multicast database via netlink" broke kernel 3.8 uapi Thomas Backlund
2013-01-16 5:51 ` Cong Wang
2013-01-16 6:06 ` Redefinition of struct in6_addr in <netinet/in.h> and <linux/in6.h> Cong Wang
2013-01-16 14:21 ` YOSHIFUJI Hideaki
2013-01-16 15:47 ` Ben Hutchings
2013-01-16 17:04 ` Mike Frysinger
2013-01-16 17:10 ` Ben Hutchings
2013-01-16 17:28 ` Mike Frysinger
2013-01-16 18:59 ` David Miller
2013-01-16 19:22 ` Mike Frysinger
2013-01-16 19:25 ` David Miller
2013-01-17 3:40 ` Cong Wang
2013-01-17 3:55 ` [libvirt] " Jike Song
2013-01-17 6:59 ` Cong Wang
2013-01-17 7:02 ` Cong Wang
2013-01-16 18:57 ` David Miller
2013-01-16 19:29 ` Mike Frysinger [this message]
2013-01-17 2:15 ` Carlos O'Donell
2013-01-17 3:10 ` YOSHIFUJI Hideaki
2013-01-17 3:15 ` David Miller
2013-01-18 4:20 ` Mike Frysinger
2013-01-18 4:22 ` Carlos O'Donell
2013-01-18 4:34 ` Mike Frysinger
2013-01-18 10:44 ` Pedro Alves
2013-01-18 13:35 ` Carlos O'Donell
2013-01-18 14:24 ` YOSHIFUJI Hideaki
2013-01-18 14:36 ` Pedro Alves
2013-01-18 14:54 ` Carlos O'Donell
2013-01-21 0:54 ` Mike Frysinger
2013-01-17 3:22 ` YOSHIFUJI Hideaki
2013-01-18 4:13 ` Carlos O'Donell
2013-01-16 21:45 ` David Miller
2013-01-17 1:58 ` Carlos O'Donell
2013-01-17 2:05 ` David Miller
2013-01-17 10:57 ` Jan Engelhardt
2013-01-18 4:14 ` Mike Frysinger
2013-01-18 4:55 ` David Miller
2013-01-18 5:27 ` Mike Frysinger
2013-03-13 15:17 ` [libvirt] if_bridge.h: include in6.h for struct in6_addr use Kumar Gala
2013-03-13 16:24 ` Eric Blake
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