From: Zechuan Chen <chenzechuan1@huawei.com>

Date: Tue, 28 Dec 2021 19:13:38 +0800

Subject: perf probe: Fix ppc64 'perf probe add events failed' case

Git-commit: 4624f199327a704dd1069aca1c3cadb8f2a28c6f

Patch-mainline: v5.17-rc1

References: git-fixes

​

Because of commit bf794bf52a80c627 ("powerpc/kprobes: Fix kallsyms

lookup across powerpc ABIv1 and ABIv2"), in ppc64 ABIv1, our perf

command eliminates the need to use the prefix "." at the symbol name.

​

But when the command "perf probe -a schedule" is executed on ppc64

ABIv1, it obtains two symbol address information through /proc/kallsyms,

for example:

​

  cat /proc/kallsyms | grep -w schedule

  c000000000657020 T .schedule

  c000000000d4fdb8 D schedule

​

The symbol "D schedule" is not a function symbol, and perf will print:

"p:probe/schedule _text+13958584"Failed to write event: Invalid argument

​

Therefore, when searching symbols from map and adding probe point for

them, a symbol type check is added. If the type of symbol is not a

function, skip it.

​

Fixes: bf794bf52a80c627 ("powerpc/kprobes: Fix kallsyms lookup across powerpc ABIv1 and ABIv2")

Signed-off-by: Zechuan Chen <chenzechuan1@huawei.com>

Acked-by: Masami Hiramatsu <mhiramat@kernel.org>

Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>

Cc: Ingo Molnar <mingo@redhat.com>

Cc: Jianlin Lv <Jianlin.Lv@arm.com>

Cc: Jin Yao <yao.jin@linux.intel.com>

Cc: Jiri Olsa <jolsa@redhat.com>

Cc: Mark Rutland <mark.rutland@arm.com>

Cc: Michael Ellerman <mpe@ellerman.id.au>

Cc: Namhyung Kim <namhyung@kernel.org>

Cc: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com>

Cc: Peter Zijlstra <peterz@infradead.org>

Cc: Ravi Bangoria <ravi.bangoria@linux.ibm.com>

Cc: Yang Jihong <yangjihong1@huawei.com>

Link: https://lore.kernel.org/r/20211228111338.218602-1-chenzechuan1@huawei.com

Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

Signed-off-by: Tony Jones <tonyj@suse.de>

---

 tools/perf/util/probe-event.c | 3 +++

 1 file changed, 3 insertions(+)

​

diff --git a/tools/perf/util/probe-event.c b/tools/perf/util/probe-event.c

index b2a02c9ab8ea..a834918a0a0d 100644

--- a/tools/perf/util/probe-event.c

+++ b/tools/perf/util/probe-event.c

@@ -3083,6 +3083,9 @@ static int find_probe_trace_events_from_map(struct perf_probe_event *pev,

    for (j = 0; j < num_matched_functions; j++) {

        sym = syms[j];

+       if (sym->type != STT_FUNC)

+           continue;

+

        /* There can be duplicated symbols in the map */

        for (i = 0; i < j; i++)

            if (sym->start == syms[i]->start) {

​

​