libbpf: Fix readelf output parsing for Fedora

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.

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>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Andrii Nakryiko <andriin@fb.com>
Cc: Aurelien Jarno <aurelien@aurel32.net>
Link: https://lore.kernel.org/bpf/20191213101114.GA3986@calabresa

diff --git a/tools/lib/bpf/Makefile b/tools/lib/bpf/Makefile
index defae23a0169d8d4b653ab7305c1f3bf3c664742..23ae06c43d08856f35d4a0d5dbec7a1049d7c356 100644 (file)
--- 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 |                   \