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From 746f534a4809e07f427f7d13d10f3a6a9641e5c3 Mon Sep 17 00:00:00 2001
From: Tony Ambardar <tony.ambardar@gmail.com>
Date: Sat, 5 Sep 2020 14:48:31 -0700
Subject: [PATCH] tools/libbpf: Avoid counting local symbols in ABI check

Ignore the below, we are actually reverting this patch for now

Encountered the following failure building libbpf from kernel 5.8.5 sources
with GCC 8.4.0 and binutils 2.34: (long paths shortened)

Investigation shows _fini and _init are actually local symbols counted
amongst global ones:

  $ readelf --dyn-syms --wide libbpf.so|head -10

  Symbol table '.dynsym' contains 343 entries:
     Num:    Value  Size Type    Bind   Vis      Ndx Name
       0: 00000000     0 NOTYPE  LOCAL  DEFAULT  UND
       1: 00004098     0 SECTION LOCAL  DEFAULT   11
       2: 00004098     8 FUNC    LOCAL  DEFAULT   11 _init@@LIBBPF_0.0.1
       3: 00023040     8 FUNC    LOCAL  DEFAULT   14 _fini@@LIBBPF_0.0.1
       4: 00000000     0 OBJECT  GLOBAL DEFAULT  ABS LIBBPF_0.0.4
       5: 00000000     0 OBJECT  GLOBAL DEFAULT  ABS LIBBPF_0.0.1
       6: 0000ffa4     8 FUNC    GLOBAL DEFAULT   12 bpf_object__find_map_by_offset@@LIBBPF_0.0.1

A previous commit filtered global symbols in sharedobjs/libbpf-in.o. Do the
same with the libbpf.so DSO for consistent comparison.

Fixes: 306b267cb3c4 ("libbpf: Verify versioned symbols")
Signed-off-by: Tony Ambardar <Tony.Ambardar@gmail.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Andrii Nakryiko <andriin@fb.com>
Link: https://lore.kernel.org/bpf/20200905214831.1565465-1-Tony.Ambardar@gmail.com
---
 tools/lib/bpf/Makefile | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/tools/lib/bpf/Makefile b/tools/lib/bpf/Makefile
index b78484e7a608..9ae8f4ef0aac 100644
--- a/tools/lib/bpf/Makefile
+++ b/tools/lib/bpf/Makefile
@@ -152,7 +152,6 @@ GLOBAL_SYM_COUNT = $(shell readelf -s --wide $(BPF_IN_SHARED) | \
 			   awk '/GLOBAL/ && /DEFAULT/ && !/UND/ {print $$NF}' | \
 			   sort -u | wc -l)
 VERSIONED_SYM_COUNT = $(shell readelf --dyn-syms --wide $(OUTPUT)libbpf.so | \
-			      awk '/GLOBAL/ && /DEFAULT/ && !/UND/ {print $$NF}' | \
 			      grep -Eo '[^ ]+@LIBBPF_' | cut -d@ -f1 | sort -u | wc -l)

 CMD_TARGETS = $(LIB_TARGET) $(PC_FILE)
@@ -219,7 +220,6 @@ check_abi: $(OUTPUT)libbpf.so
 		    awk '/GLOBAL/ && /DEFAULT/ && !/UND/ {print $$NF}'|  \
 		    sort -u > $(OUTPUT)libbpf_global_syms.tmp;		 \
 		readelf --dyn-syms --wide $(OUTPUT)libbpf.so |		 \
-		    awk '/GLOBAL/ && /DEFAULT/ && !/UND/ {print $$NF}'|  \
 		    grep -Eo '[^ ]+@LIBBPF_' | cut -d@ -f1 |		 \
 		    sort -u > $(OUTPUT)libbpf_versioned_syms.tmp; 	 \
 		diff -u $(OUTPUT)libbpf_global_syms.tmp			 \
-- 
2.28.0