From: Rich Felker <dalias@libc.org>
To: David Miller <davem@davemloft.net>
Cc: AWilcox@Wilcox-Tech.com, netdev@vger.kernel.org,
linux-api@vger.kernel.org, musl@lists.openwall.com
Subject: Re: Re: [PATCH] uapi: Prevent redefinition of struct iphdr
Date: Wed, 25 Dec 2019 20:05:15 -0500 [thread overview]
Message-ID: <20191226010515.GD30412@brightrain.aerifal.cx> (raw)
In-Reply-To: <20191225.163411.1590483851343305623.davem@davemloft.net>
On Wed, Dec 25, 2019 at 04:34:11PM -0800, David Miller wrote:
> From: "A. Wilcox" <AWilcox@Wilcox-Tech.com>
> Date: Sun, 22 Dec 2019 00:02:27 -0600
>
> > @@ -83,6 +83,13 @@
> >
> > #define IPV4_BEET_PHMAXLEN 8
> >
> > +/* Allow libcs to deactivate this - musl has its own copy in <netinet/ip.h> */
> > +
> > +#ifndef __UAPI_DEF_IPHDR
> > +#define __UAPI_DEF_IPHDR 1
> > +#endif
>
> How is this a musl-only problem?
I don't think it is, unless glibc's includes linux/ip.h to get the
definition, which does not seem to be the case -- at least not on the
Debian system I had handy to check on.
> I see that glibc also defines struct iphdr
> in netinet/ip.h, so why doesn't it also suffer from this?
Maybe it does.
> I find it really strange that this, therefore, only happens for musl
> and we haven't had thousands of reports of this conflict with glibc
> over the years.
It's possible that there's software that's including just one of the
headers conditional on __GLIBC__, and including both otherwise, or
something like that. Arguably this should be considered unsupported
usage; there are plenty of headers where that doesn't work and
shouldn't be expected to.
> I want an explanation, and suitably appropriate adjustments to the commit
> message and comments of this change.
Agreed. Commit messages should not imply that something is a
musl-specific workaround when it's generally the right thing to do.
Rich
next prev parent reply other threads:[~2019-12-26 1:05 UTC|newest]
Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-12-22 6:02 A. Wilcox
2019-12-26 0:34 ` David Miller
2019-12-26 1:05 ` Rich Felker [this message]
2019-12-26 3:49 ` [musl] " David Miller
2019-12-26 11:13 ` Daniel Kolesa
2019-12-30 17:12 ` Rich Felker
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