> From: Wang Nan [mailto:wangn...@huawei.com]
>
> '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().
Oops, OK this is a bug.
Thanks!
Acked-by: Masami Hiramatsu <masami.hiramatsu...@hitachi.com>
>
> 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
