3.16.82-rc1 review patch. If anyone has any objections, please let me know.
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From: Masami Hiramatsu mhiramat@kernel.org
commit 3895534dd78f0fd4d3f9e05ee52b9cdd444a743e upstream.
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@dev... Signed-off-by: Arnaldo Carvalho de Melo acme@redhat.com Signed-off-by: Ben Hutchings ben@decadent.org.uk --- tools/perf/util/probe-finder.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-)
--- a/tools/perf/util/probe-finder.c +++ b/tools/perf/util/probe-finder.c @@ -1345,7 +1345,7 @@ int debuginfo__find_probe_point(struct d /* 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; @@ -1362,7 +1362,7 @@ int debuginfo__find_probe_point(struct d 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.