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    Subject[PATCH 4.4 039/137] perf probe: Fix to list probe event with correct line number
    Date
    From: Masami Hiramatsu <mhiramat@kernel.org>

    [ Upstream commit 3895534dd78f0fd4d3f9e05ee52b9cdd444a743e ]

    Since debuginfo__find_probe_point() uses dwarf_entrypc() for finding the
    entry address of the function on which a probe is, it will fail when the
    function DIE has only ranges attribute.

    To fix this issue, use die_entrypc() instead of dwarf_entrypc().

    Without this fix, perf probe -l shows incorrect offset:

    # perf probe -l
    probe:clear_tasks_mm_cpumask (on clear_tasks_mm_cpumask+18446744071579263632@work/linux/linux/kernel/cpu.c)
    probe:clear_tasks_mm_cpumask_1 (on clear_tasks_mm_cpumask+18446744071579263752@work/linux/linux/kernel/cpu.c)

    With this:

    # perf probe -l
    probe:clear_tasks_mm_cpumask (on clear_tasks_mm_cpumask@work/linux/linux/kernel/cpu.c)
    probe:clear_tasks_mm_cpumask_1 (on clear_tasks_mm_cpumask:21@work/linux/linux/kernel/cpu.c)

    Committer testing:

    Before:

    [root@quaco ~]# perf probe -l
    probe:clear_tasks_mm_cpumask (on clear_tasks_mm_cpumask+18446744071579765152@kernel/cpu.c)
    [root@quaco ~]#

    After:

    [root@quaco ~]# perf probe -l
    probe:clear_tasks_mm_cpumask (on clear_tasks_mm_cpumask@kernel/cpu.c)
    [root@quaco ~]#

    Fixes: 1d46ea2a6a40 ("perf probe: Fix listing incorrect line number with inline function")
    Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
    Tested-by: Arnaldo Carvalho de Melo <acme@redhat.com>
    Cc: Jiri Olsa <jolsa@redhat.com>
    Cc: Namhyung Kim <namhyung@kernel.org>
    Link: http://lore.kernel.org/lkml/157199321227.8075.14655572419136993015.stgit@devnote2
    Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
    Signed-off-by: Sasha Levin <sashal@kernel.org>
    ---
    tools/perf/util/probe-finder.c | 4 ++--
    1 file changed, 2 insertions(+), 2 deletions(-)

    diff --git a/tools/perf/util/probe-finder.c b/tools/perf/util/probe-finder.c
    index fdd87c7e3e91..dce40710b5de 100644
    --- a/tools/perf/util/probe-finder.c
    +++ b/tools/perf/util/probe-finder.c
    @@ -1481,7 +1481,7 @@ int debuginfo__find_probe_point(struct debuginfo *dbg, unsigned long addr,
    /* Get function entry information */
    func = basefunc = dwarf_diename(&spdie);
    if (!func ||
    - dwarf_entrypc(&spdie, &baseaddr) != 0 ||
    + die_entrypc(&spdie, &baseaddr) != 0 ||
    dwarf_decl_line(&spdie, &baseline) != 0) {
    lineno = 0;
    goto post;
    @@ -1498,7 +1498,7 @@ int debuginfo__find_probe_point(struct debuginfo *dbg, unsigned long addr,
    while (die_find_top_inlinefunc(&spdie, (Dwarf_Addr)addr,
    &indie)) {
    /* There is an inline function */
    - if (dwarf_entrypc(&indie, &_addr) == 0 &&
    + if (die_entrypc(&indie, &_addr) == 0 &&
    _addr == addr) {
    /*
    * addr is at an inline function entry.
    --
    2.20.1


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