From mboxrd@z Thu Jan 1 00:00:00 1970 From: Thomas Petazzoni Date: Wed, 16 Nov 2016 23:30:01 +0100 Subject: [Buildroot] [PATCH v2 1/3] toolchain: workaround musl/kernel headers conflict In-Reply-To: References: Message-ID: <20161116233001.79b36069@free-electrons.com> List-Id: MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: buildroot@busybox.net Hello, On Thu, 10 Nov 2016 15:27:11 +0200, Baruch Siach wrote: > Rick Felker suggested[1] this hack as a workaround to musl libc conflict with > kernel headers: > > The problem is linux/libc-compat.h, which should fix this, only works > on glibc, by design. See: > > #ifndef _LIBC_COMPAT_H > #define _LIBC_COMPAT_H > > /* We have included glibc headers... */ > #if defined(__GLIBC__) > > /* Coordinate with glibc netinet/in.h header. */ > #if defined(_NETINET_IN_H) > > If you patch it like this: > > -#if defined(__GLIBC__) > +#if 1 > > then it should mostly work but it's still all a big hack. I think > that's what distros are doing. The problem is that the same header is > trying to do two different things: > > 1. Provide extra linux-kernel-API stuff that's not in the > libc/userspace headers. > > 2. Provide definitions of the standard types and constants for uClibc > and klibc, which don't have complete libc headers and rely on the > kernel headers for definitions. > > These two uses really should be separated out into separate headers so > that the latter only get included explicitly by uClibc and klibc and > otherwise remain completely unused. But that would require coordinated > changes/upgrades which are unlikely to happen. :( > > Upstream musl still evaluates[2][3] a permanent solution. > > With this in place we can revert (at least) commits a167081c5d (bridge-utils: > fix build with musl) and e74d4fc4932 (norm: add patch to fix musl build). > > [1] http://www.openwall.com/lists/musl/2015/10/08/2 > [2] http://git.musl-libc.org/cgit/musl/commit/?id=04983f2272382af92eb8f8838964ff944fbb8258 > [3] http://www.openwall.com/lists/musl/2016/11/09/2 > > Signed-off-by: Baruch Siach > --- > v2: > * Add Rick's explanation in the commit log (Arnout) > * Link to more recent upstream changes > --- > toolchain/toolchain/toolchain.mk | 14 ++++++++++++++ > 1 file changed, 14 insertions(+) Series applied to the next branch. Thanks! Thomas -- Thomas Petazzoni, CTO, Free Electrons Embedded Linux, Kernel and Android engineering http://free-electrons.com