@@ -1483,6 +1483,7 @@ int bpf__setup_stdout(struct perf_evlist *evlist __maybe_unused)
{
struct bpf_map_priv *tmpl_priv = NULL;
struct bpf_object *obj, *tmp;
+ struct perf_evsel *evsel = NULL;
struct bpf_map *map;
int err;
bool need_init = false;
@@ -1507,8 +1508,16 @@ int bpf__setup_stdout(struct perf_evlist *evlist __maybe_unused)
if (!need_init)
return 0;
- if (!tmpl_priv)
- return 0;
+ if (!tmpl_priv) {
+ err = parse_events(evlist, "bpf-output/no-inherit=1,name=__bpf_stdout__/",
+ NULL);
+ if (err) {
+ pr_debug("ERROR: failed to create bpf-output event\n");
+ return -err;
+ }
+
+ evsel = perf_evlist__last(evlist);
+ }
bpf__for_each_stdout_map(map, obj, tmp) {
struct bpf_map_priv *priv;
@@ -1519,14 +1528,24 @@ int bpf__setup_stdout(struct perf_evlist *evlist __maybe_unused)
if (priv)
continue;
- priv = bpf_map_priv__clone(tmpl_priv);
- if (!priv)
- return -ENOMEM;
+ if (tmpl_priv) {
+ priv = bpf_map_priv__clone(tmpl_priv);
+ if (!priv)
+ return -ENOMEM;
- err = bpf_map__set_private(map, priv, bpf_map_priv__clear);
- if (err) {
- bpf_map_priv__clear(map, priv);
- return err;
+ err = bpf_map__set_private(map, priv, bpf_map_priv__clear);
+ if (err) {
+ bpf_map_priv__clear(map, priv);
+ return err;
+ }
+ } else if (evsel) {
+ struct bpf_map_op *op;
+
+ op = bpf_map__add_newop(map, NULL);
+ if (IS_ERR(op))
+ return PTR_ERR(op);
+ op->op_type = BPF_MAP_OP_SET_EVSEL;
+ op->v.evsel = evsel;
}
}
This patch allows ignoring bpf-output event setting in cmdline. By adding a map named '__bpf_stdout__', perf automatically creates an event for it. For example: # perf record -e ./test_bpf_trace.c usleep 100000 [ perf record: Woken up 1 times to write data ] [ perf record: Captured and wrote 0.012 MB perf.data (2 samples) ] # ~/perf script usleep 4639 [000] 261895.307826: 0 __bpf_stdout__: ffffffff810eb9a1 ... BPF output: 0000: 52 61 69 73 65 20 61 20 Raise a 0008: 42 50 46 20 65 76 65 6e BPF even 0010: 74 21 00 00 t!.. BPF string: "Raise a BPF event!" usleep 4639 [000] 261895.407883: 0 __bpf_stdout__: ffffffff8105d609 ... BPF output: 0000: 52 61 69 73 65 20 61 20 Raise a 0008: 42 50 46 20 65 76 65 6e BPF even 0010: 74 21 00 00 t!.. BPF string: "Raise a BPF event!" perf record -e ./test_bpf_trace.c usleep 100000 equals to perf record -e bpf-output/no-inherit=1,name=__bpf_stdout__/ \ -e ./test_bpf_trace.c/map:__bpf_stdout__.event=__bpf_stdout__/ \ usleep 100000 Where test_bpf_trace.c is: /************************ BEGIN **************************/ #include <uapi/linux/bpf.h> struct bpf_map_def { unsigned int type; unsigned int key_size; unsigned int value_size; unsigned int max_entries; }; #define SEC(NAME) __attribute__((section(NAME), used)) static u64 (*ktime_get_ns)(void) = (void *)BPF_FUNC_ktime_get_ns; static int (*trace_printk)(const char *fmt, int fmt_size, ...) = (void *)BPF_FUNC_trace_printk; static int (*get_smp_processor_id)(void) = (void *)BPF_FUNC_get_smp_processor_id; static int (*perf_event_output)(void *, struct bpf_map_def *, int, void *, unsigned long) = (void *)BPF_FUNC_perf_event_output; struct bpf_map_def SEC("maps") __bpf_stdout__ = { .type = BPF_MAP_TYPE_PERF_EVENT_ARRAY, .key_size = sizeof(int), .value_size = sizeof(u32), .max_entries = __NR_CPUS__, }; static inline int __attribute__((always_inline)) func(void *ctx, int type) { char output_str[] = "Raise a BPF event!"; char err_str[] = "BAD %d\n"; int err; err = perf_event_output(ctx, &channel, get_smp_processor_id(), &output_str, sizeof(output_str)); if (err) trace_printk(err_str, sizeof(err_str), err); return 1; } SEC("func_begin=sys_nanosleep") int func_begin(void *ctx) {return func(ctx, 1);} SEC("func_end=sys_nanosleep%return") int func_end(void *ctx) { return func(ctx, 2);} char _license[] SEC("license") = "GPL"; int _version SEC("version") = LINUX_VERSION_CODE; /************************* END ***************************/ Signed-off-by: Wang Nan <wangnan0@hauwei.com> Cc: Arnaldo Carvalho de Melo <acme@redhat.com> Cc: Jiri Olsa <jolsa@kernel.org> Cc: Li Zefan <lizefan@huawei.com> Cc: pi3orama@163.com --- tools/perf/util/bpf-loader.c | 37 ++++++++++++++++++++++++++++--------- 1 file changed, 28 insertions(+), 9 deletions(-) -- 1.8.3.4