From c17c29b9f87e0536db799f9fd5c94b85c1a32892 Mon Sep 17 00:00:00 2001 From: Rodrigo Rebello Date: Mon, 30 Nov 2015 13:40:39 -0200 Subject: [PATCH] conntrack-tools: work around build issue with musl Building conntrack-tools with kernel headers >= 4.2 + musl fails due to a well-known symbol clash that occurs when userspace and kernel headers are included simultaneously (see [1], question 7, for details). In the case of conntrack-tools, the inclusion of both 'netinet/in.h' and 'linux/in.h' occurs inside the C helper files (src/helpers/*.c) indirectly via e.g. 'libnetfilter_conntrack/libnetfilter_conntrack.h', which itself includes 'netinet/in.h', and 'linux/netfilter.h', which includes 'linux/in.h' in kernel headers >= 4.2. The approach to solving this type of conflict with musl usually involves removing the inclusion of kernel headers or refactoring the code so as to avoid the mentioned simultaneous inclusion. This is unfortunately non-trivial in the case of conntrack-tools since the clashing headers get included indirectly by headers that are strictly necessary (because of definitions used in some helper callbacks). Work around the issue by defining __GLIBC__ when musl is used. This eliminates the conflicts as the kernel headers avoid redefining certain symbols when they see __GLIBC__ defined (linux/libc-compat.h). Note that other glibc-compatible libraries, like uClibc, already do that internally. Fixes: http://autobuild.buildroot.net/results/66e/66ec247fa0fc385bef8d2084c65bf5cad3a8e8ca/ http://autobuild.buildroot.net/results/624/624a0d48decd819eb58cbb3c58ee904b87ebfb21/ [1] http://wiki.musl-libc.org/wiki/FAQ Signed-off-by: Rodrigo Rebello Signed-off-by: Peter Korsgaard --- package/conntrack-tools/conntrack-tools.mk | 16 ++++++++++++++-- 1 file changed, 14 insertions(+), 2 deletions(-) diff --git a/package/conntrack-tools/conntrack-tools.mk b/package/conntrack-tools/conntrack-tools.mk index eac5841168..728758789c 100644 --- a/package/conntrack-tools/conntrack-tools.mk +++ b/package/conntrack-tools/conntrack-tools.mk @@ -13,10 +13,22 @@ CONNTRACK_TOOLS_DEPENDENCIES = host-pkgconf \ CONNTRACK_TOOLS_LICENSE = GPLv2+ CONNTRACK_TOOLS_LICENSE_FILES = COPYING +CONNTRACK_TOOLS_CFLAGS = $(TARGET_CFLAGS) + +# Some of conntrack-tools source files include both linux/in.h (via +# linux/netfilter.h for kernel headers >= 4.2) and netinet/in.h, which +# causes some symbol conflicts when musl is used. Defining __GLIBC__ +# works around that issue since the kernel headers are prepared to +# avoid redefinition of certain symbols when they see __GLIBC__. +ifeq ($(BR2_TOOLCHAIN_USES_MUSL),y) +CONNTRACK_TOOLS_CFLAGS += -D__GLIBC__ +endif + ifeq ($(BR2_PACKAGE_LIBTIRPC),y) -CONNTRACK_TOOLS_CONF_ENV += \ - CFLAGS="$(TARGET_CFLAGS) `$(PKG_CONFIG_HOST_BINARY) --cflags libtirpc`" +CONNTRACK_TOOLS_CFLAGS += `$(PKG_CONFIG_HOST_BINARY) --cflags libtirpc` CONNTRACK_TOOLS_DEPENDENCIES += libtirpc host-pkgconf endif +CONNTRACK_TOOLS_CONF_ENV = CFLAGS="$(CONNTRACK_TOOLS_CFLAGS)" + $(eval $(autotools-package))