[PATCH] libbpf: Fix readelf output parsing for Fedora

From: Thadeu Lima de Souza Cascardo <cascardo@canonical.com>
To: Justin Forbes <jmforbes@linuxtx.org>
Cc: Daniel Borkmann <daniel@iogearbox.net>,
	Song Liu <songliubraving@fb.com>,
	Andrii Nakryiko <andriin@fb.com>,
	Alexei Starovoitov <ast@kernel.org>,
	LKML <linux-kernel@vger.kernel.org>,
	"open list:BPF (Safe dynamic programs and tools)" 
	<netdev@vger.kernel.org>, Yonghong Song <yhs@fb.com>,
	"open list:BPF (Safe dynamic programs and tools)" 
	<bpf@vger.kernel.org>,
	linuxppc-dev@lists.ozlabs.org, Martin KaFai Lau <kafai@fb.com>,
	Aurelien Jarno <aurelien@aurel32.net>,
	debian-kernel@lists.debian.org
Subject: [PATCH] libbpf: Fix readelf output parsing for Fedora
Date: Fri, 13 Dec 2019 07:11:14 -0300	[thread overview]
Message-ID: <20191213101114.GA3986@calabresa> (raw)
In-Reply-To: <CAFxkdAp9OGjJS1Sdny+TiG2+zU4n0Nj+ZVrZt5J6iVsS_zqqcw@mail.gmail.com>

Fedora binutils has been patched to show "other info" for a symbol at the
end of the line. This was done in order to support unmaintained scripts
that would break with the extra info. [1]

[1] https://src.fedoraproject.org/rpms/binutils/c/b8265c46f7ddae23a792ee8306fbaaeacba83bf8

This in turn has been done to fix the build of ruby, because of checksec.
[2] Thanks Michael Ellerman for the pointer.

[2] https://bugzilla.redhat.com/show_bug.cgi?id=1479302

As libbpf Makefile is not unmaintained, we can simply deal with either
output format, by just removing the "other info" field, as it always comes
inside brackets.

Cc: Aurelien Jarno <aurelien@aurel32.net>
Fixes: 3464afdf11f9 (libbpf: Fix readelf output parsing on powerpc with recent binutils)
Reported-by: Justin Forbes <jmforbes@linuxtx.org>
Signed-off-by: Thadeu Lima de Souza Cascardo <cascardo@canonical.com>
---
 tools/lib/bpf/Makefile | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/tools/lib/bpf/Makefile b/tools/lib/bpf/Makefile
index defae23a0169..23ae06c43d08 100644
--- a/tools/lib/bpf/Makefile
+++ b/tools/lib/bpf/Makefile
@@ -147,6 +147,7 @@ TAGS_PROG := $(if $(shell which etags 2>/dev/null),etags,ctags)
 
 GLOBAL_SYM_COUNT = $(shell readelf -s --wide $(BPF_IN_SHARED) | \
 			   cut -d "@" -f1 | sed 's/_v[0-9]_[0-9]_[0-9].*//' | \
+			   sed 's/\[.*\]//' | \
 			   awk '/GLOBAL/ && /DEFAULT/ && !/UND/ {print $$NF}' | \
 			   sort -u | wc -l)
 VERSIONED_SYM_COUNT = $(shell readelf -s --wide $(OUTPUT)libbpf.so | \
@@ -213,6 +214,7 @@ check_abi: $(OUTPUT)libbpf.so
 		     "versioned in $(VERSION_SCRIPT)." >&2;		 \
 		readelf -s --wide $(BPF_IN_SHARED) |			 \
 		    cut -d "@" -f1 | sed 's/_v[0-9]_[0-9]_[0-9].*//' |	 \
+		    sed 's/\[.*\]//' |					 \
 		    awk '/GLOBAL/ && /DEFAULT/ && !/UND/ {print $$NF}'|  \
 		    sort -u > $(OUTPUT)libbpf_global_syms.tmp;		 \
 		readelf -s --wide $(OUTPUT)libbpf.so |			 \
-- 
2.24.0

