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author | Masami Hiramatsu <mhiramat@kernel.org> | 2019-10-25 17:46:34 +0900 |
---|---|---|
committer | Arnaldo Carvalho de Melo <acme@redhat.com> | 2019-11-06 15:43:06 -0300 |
commit | 5d16dbcc311d91267ddb45c6da4f187be320ecee (patch) | |
tree | 0e967740f7e09228dc9cb36d66797dde58d3318c /tools/perf/util/probe-finder.c | |
parent | 07d369857808b7e8e471bbbbb0074a6718f89b31 (diff) | |
download | linux-5d16dbcc311d91267ddb45c6da4f187be320ecee.tar.bz2 |
perf probe: Fix to probe a function which has no entry pc
Fix 'perf probe' to probe a function which has no entry pc or low pc but
only has ranges attribute.
probe_point_search_cb() uses dwarf_entrypc() to get the probe address,
but that doesn't work for the function DIE which has only ranges
attribute. Use die_entrypc() instead.
Without this fix:
# perf probe -k ../build-x86_64/vmlinux -D clear_tasks_mm_cpumask:0
Probe point 'clear_tasks_mm_cpumask' not found.
Error: Failed to add events.
With this:
# perf probe -k ../build-x86_64/vmlinux -D clear_tasks_mm_cpumask:0
p:probe/clear_tasks_mm_cpumask clear_tasks_mm_cpumask+0
Committer testing:
Before:
[root@quaco ~]# perf probe clear_tasks_mm_cpumask:0
Probe point 'clear_tasks_mm_cpumask' not found.
Error: Failed to add events.
[root@quaco ~]#
After:
[root@quaco ~]# perf probe clear_tasks_mm_cpumask:0
Added new event:
probe:clear_tasks_mm_cpumask (on clear_tasks_mm_cpumask)
You can now use it in all perf tools, such as:
perf record -e probe:clear_tasks_mm_cpumask -aR sleep 1
[root@quaco ~]#
Using it with 'perf trace':
[root@quaco ~]# perf trace -e probe:clear_tasks_mm_cpumask
Doesn't seem to be used in x86_64:
$ find . -name "*.c" | xargs grep clear_tasks_mm_cpumask
./kernel/cpu.c: * clear_tasks_mm_cpumask - Safely clear tasks' mm_cpumask for a CPU
./kernel/cpu.c:void clear_tasks_mm_cpumask(int cpu)
./arch/xtensa/kernel/smp.c: clear_tasks_mm_cpumask(cpu);
./arch/csky/kernel/smp.c: clear_tasks_mm_cpumask(cpu);
./arch/sh/kernel/smp.c: clear_tasks_mm_cpumask(cpu);
./arch/arm/kernel/smp.c: clear_tasks_mm_cpumask(cpu);
./arch/powerpc/mm/nohash/mmu_context.c: clear_tasks_mm_cpumask(cpu);
$ find . -name "*.h" | xargs grep clear_tasks_mm_cpumask
./include/linux/cpu.h:void clear_tasks_mm_cpumask(int cpu);
$ find . -name "*.S" | xargs grep clear_tasks_mm_cpumask
$
Fixes: e1ecbbc3fa83 ("perf probe: Fix to handle optimized not-inlined functions")
Reported-by: Arnaldo Carvalho de Melo <acme@kernel.org>
Tested-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Link: http://lore.kernel.org/lkml/157199319438.8075.4695576954550638618.stgit@devnote2
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Diffstat (limited to 'tools/perf/util/probe-finder.c')
-rw-r--r-- | tools/perf/util/probe-finder.c | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/tools/perf/util/probe-finder.c b/tools/perf/util/probe-finder.c index 2b6513e5725c..71633f55f045 100644 --- a/tools/perf/util/probe-finder.c +++ b/tools/perf/util/probe-finder.c @@ -982,7 +982,7 @@ static int probe_point_search_cb(Dwarf_Die *sp_die, void *data) param->retval = find_probe_point_by_line(pf); } else if (die_is_func_instance(sp_die)) { /* Instances always have the entry address */ - dwarf_entrypc(sp_die, &pf->addr); + die_entrypc(sp_die, &pf->addr); /* But in some case the entry address is 0 */ if (pf->addr == 0) { pr_debug("%s has no entry PC. Skipped\n", |