'perf probe -l' panic if there is a manually inserted probing point
with absolute address. For example:
# echo 'p:probe/abs_ffffffff811e6615 0xffffffff811e6615' >
/sys/kernel/debug/tracing/kprobe_events
# perf probe -l
Segmentation fault (core dumped)
This patch fix this problem by considering the situation that
"tp->symbol == NULL" in find_perf_probe_point_from_dwarf() and
find_perf_probe_point_from_map().
After this patch:
# perf probe -l
probe:abs_ffffffff811e6615 (on SyS_write+5@fs/read_write.c)
And when debug info is missing:
# rm -rf ~/.debug
# mv /lib/modules/4.2.0-rc1+/build/vmlinux
/lib/modules/4.2.0-rc1+/build/vmlinux.bak
# perf probe -l
probe:abs_ffffffff811e6615 (on sys_write+5)
Signed-off-by: Wang Nan <wangn...@huawei.com>
Cc: Arnaldo Carvalho de Melo <a...@kernel.org>
Cc: Ingo Molnar <mi...@redhat.com>
Cc: Masami Hiramatsu <masami.hiramatsu...@hitachi.com>
Cc: Namhyung Kim <namhy...@kernel.org>
---
tools/perf/util/probe-event.c | 8 ++++----
1 file changed, 4 insertions(+), 4 deletions(-)
diff --git a/tools/perf/util/probe-event.c b/tools/perf/util/probe-event.c
index f07374b..6c7e538 100644
--- a/tools/perf/util/probe-event.c
+++ b/tools/perf/util/probe-event.c
@@ -515,7 +515,7 @@ static int find_perf_probe_point_from_dwarf(struct
probe_trace_point *tp,
if (ret < 0)
goto error;
addr += stext;
- } else {
+ } else if (tp->symbol) {
addr = kernel_get_symbol_address_by_name(tp->symbol, false);
if (addr == 0)
goto error;
@@ -1815,17 +1815,17 @@ static int find_perf_probe_point_from_map(struct
probe_trace_point *tp,
{
struct symbol *sym = NULL;
struct map *map;
- u64 addr;
+ u64 addr = tp->address;
int ret = -ENOENT;
if (!is_kprobe) {
map = dso__new_map(tp->module);
if (!map)
goto out;
- addr = tp->address;
sym = map__find_symbol(map, addr, NULL);
} else {
- addr = kernel_get_symbol_address_by_name(tp->symbol, true);
+ if (tp->symbol)
+ addr = kernel_get_symbol_address_by_name(tp->symbol,
true);
if (addr) {
addr += tp->offset;
sym = __find_kernel_function(addr, &map);
--
1.8.3.4
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