perf probe: Fix to list probe event with correct line number

[ 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>

diff --git a/tools/perf/util/probe-finder.c b/tools/perf/util/probe-finder.c
index c37fbef..c4fe067 100644 (file)
--- a/tools/perf/util/probe-finder.c
+++ b/tools/perf/util/probe-finder.c
@@ -1567,7 +1567,7 @@ 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;
@@ -1584,7 +1584,7 @@ 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.