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    Subject[PATCH 2/3] perf: Allow strong and weak functions in LIB_OBJS
    From: Ian Munsie <>

    When we build perf we place all of the .o files from the library files
    (util, arch/x/util, etc) into libperf.a which is then linked into perf.
    The problem is that the linker will by default only consider .o files
    within the .a archive if they are necessary to satisfy an unresolved
    symbol. As weak functions are not unresolved, it will not consider a .o
    file from the archive containing the strong versions of weak functions
    unless it requires it for another reason.

    This patch adds the --whole-archive flags to the linker when passing in
    the libperf.a file to ensure that it will consider every .o file in the
    archive, not just what it believes that it needs. The end result is that
    weak functions can now be overridden by strong variants of them in the
    libperf.a file.

    Signed-off-by: Ian Munsie <>
    tools/perf/Makefile | 3 ++-
    1 files changed, 2 insertions(+), 1 deletions(-)

    diff --git a/tools/perf/Makefile b/tools/perf/Makefile
    index 2d414b3..c5f7b7f 100644
    --- a/tools/perf/Makefile
    +++ b/tools/perf/Makefile
    @@ -940,7 +940,8 @@ $(OUTPUT)perf.o: perf.c $(OUTPUT)common-cmds.h $(OUTPUT)PERF-CFLAGS

    $(OUTPUT)perf$X: $(OUTPUT)perf.o $(BUILTIN_OBJS) $(PERFLIBS)
    - $(BUILTIN_OBJS) $(LIBS) -o $@
    + $(BUILTIN_OBJS) -Wl,--whole-archive $(LIBS) \
    + -Wl,--no-whole-archive -o $@
    @rm -f trace
    @ln perf$X trace 2>/dev/null


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