This patch collects 'struct perf_evsel' for every probing points in BPF object file(s) and fill 'struct evlist'. The previous introduced dummy event now removed. After this patch, following command:
# perf record --event filter.o ls Can trace on each probing points defined in filter.o. The core of this patch is bpf__foreach_tev(), which calls a callback function for each 'struct probe_trace_event' events for a bpf program with their file descriptors. Callback function add_bpf_event() creates evsels by calling parse_events_add_tracepoint(). Since bpf-loader.c will not be built if libbpf is turned off, an empty bpf__foreach_tev() is defined in bpf-loader.h to avoid compiling error. Signed-off-by: Wang Nan <wangn...@huawei.com> Cc: Alexei Starovoitov <a...@plumgrid.com> Cc: Brendan Gregg <brendan.d.gr...@gmail.com> Cc: Daniel Borkmann <dan...@iogearbox.net> Cc: David Ahern <dsah...@gmail.com> Cc: He Kuang <heku...@huawei.com> Cc: Jiri Olsa <jo...@kernel.org> Cc: Kaixu Xia <xiaka...@huawei.com> Cc: Masami Hiramatsu <masami.hiramatsu...@hitachi.com> Cc: Namhyung Kim <namhy...@kernel.org> Cc: Paul Mackerras <pau...@samba.org> Cc: Peter Zijlstra <a.p.zijls...@chello.nl> Cc: Zefan Li <lize...@huawei.com> Cc: pi3or...@163.com Cc: Arnaldo Carvalho de Melo <a...@redhat.com> Link: http://lkml.kernel.org/n/ebpf-6yw9eg0ej3l4jnqhinngk...@git.kernel.org --- tools/perf/util/bpf-loader.c | 40 +++++++++++++++++++++++++++++++++++ tools/perf/util/bpf-loader.h | 15 +++++++++++++ tools/perf/util/parse-events.c | 48 ++++++++++++++++++++++++++++++++++++------ 3 files changed, 97 insertions(+), 6 deletions(-) diff --git a/tools/perf/util/bpf-loader.c b/tools/perf/util/bpf-loader.c index 39732a4..33e592c 100644 --- a/tools/perf/util/bpf-loader.c +++ b/tools/perf/util/bpf-loader.c @@ -254,6 +254,46 @@ int bpf__load(struct bpf_object *obj) return 0; } +int bpf__foreach_tev(struct bpf_object *obj, + bpf_prog_iter_callback_t func, + void *arg) +{ + struct bpf_program *prog; + int err; + + bpf_object__for_each_program(prog, obj) { + struct probe_trace_event *tev; + struct perf_probe_event *pev; + struct bpf_prog_priv *priv; + int i, fd; + + err = bpf_program__get_private(prog, + (void **)&priv); + if (err || !priv) { + pr_debug("bpf: failed to get private field\n"); + return -EINVAL; + } + + pev = &priv->pev; + for (i = 0; i < pev->ntevs; i++) { + tev = &pev->tevs[i]; + + fd = bpf_program__fd(prog); + if (fd < 0) { + pr_debug("bpf: failed to get file descriptor\n"); + return fd; + } + + err = (*func)(tev, fd, arg); + if (err) { + pr_debug("bpf: call back failed, stop iterate\n"); + return err; + } + } + } + return 0; +} + #define bpf__strerror_head(err, buf, size) \ char sbuf[STRERR_BUFSIZE], *emsg;\ if (!size)\ diff --git a/tools/perf/util/bpf-loader.h b/tools/perf/util/bpf-loader.h index b091ceb..4adfc03 100644 --- a/tools/perf/util/bpf-loader.h +++ b/tools/perf/util/bpf-loader.h @@ -8,11 +8,15 @@ #include <linux/compiler.h> #include <linux/err.h> #include <string.h> +#include "probe-event.h" #include "debug.h" struct bpf_object; #define PERF_BPF_PROBE_GROUP "perf_bpf_probe" +typedef int (*bpf_prog_iter_callback_t)(struct probe_trace_event *tev, + int fd, void *arg); + #ifdef HAVE_LIBBPF_SUPPORT struct bpf_object *bpf__prepare_load(const char *filename); @@ -26,6 +30,9 @@ int bpf__strerror_probe(struct bpf_object *obj, int err, int bpf__load(struct bpf_object *obj); int bpf__strerror_load(struct bpf_object *obj, int err, char *buf, size_t size); + +int bpf__foreach_tev(struct bpf_object *obj, + bpf_prog_iter_callback_t func, void *arg); #else static inline struct bpf_object * bpf__prepare_load(const char *filename __maybe_unused) @@ -41,6 +48,14 @@ static inline int bpf__unprobe(struct bpf_object *obj __maybe_unused) { return 0 static inline int bpf__load(struct bpf_object *obj __maybe_unused) { return 0; } static inline int +bpf__foreach_tev(struct bpf_object *obj __maybe_unused, + bpf_prog_iter_callback_t func __maybe_unused, + void *arg __maybe_unused) +{ + return 0; +} + +static inline int __bpf_strerror(char *buf, size_t size) { if (!size) diff --git a/tools/perf/util/parse-events.c b/tools/perf/util/parse-events.c index a7152f3..c3505fb 100644 --- a/tools/perf/util/parse-events.c +++ b/tools/perf/util/parse-events.c @@ -516,6 +516,39 @@ int parse_events_add_tracepoint(struct list_head *list, int *idx, return add_tracepoint_event(list, idx, sys, event, error); } +struct __add_bpf_event_param { + struct parse_events_evlist *data; + struct list_head *list; +}; + +static int add_bpf_event(struct probe_trace_event *tev, int fd, + void *_param) +{ + struct __add_bpf_event_param *param = _param; + struct parse_events_evlist *evlist = param->data; + struct list_head *list = param->list; + int err; + + pr_debug("add bpf event %s:%s and attach bpf program %d\n", + tev->group, tev->event, fd); + + err = parse_events_add_tracepoint(list, &evlist->idx, tev->group, + tev->event, evlist->error); + if (err) { + struct perf_evsel *evsel, *tmp; + + pr_debug("Failed to add BPF event %s:%s\n", + tev->group, tev->event); + list_for_each_entry_safe(evsel, tmp, list, node) { + list_del(&evsel->node); + perf_evsel__delete(evsel); + } + return err; + } + pr_debug("adding %s:%s\n", tev->group, tev->event); + return 0; +} + int parse_events_load_bpf_obj(struct parse_events_evlist *data, struct list_head *list, struct bpf_object *obj) @@ -523,6 +556,7 @@ int parse_events_load_bpf_obj(struct parse_events_evlist *data, int err; char errbuf[BUFSIZ]; static bool registered_unprobe_atexit = false; + struct __add_bpf_event_param param = {data, list}; if (IS_ERR(obj) || !obj) { snprintf(errbuf, sizeof(errbuf), @@ -548,12 +582,14 @@ int parse_events_load_bpf_obj(struct parse_events_evlist *data, goto errout; } - /* - * Temporary add a dummy event here so we can check whether - * basic bpf loader works. Will be removed in following patch. - */ - return parse_events_add_numeric(data, list, PERF_TYPE_SOFTWARE, - PERF_COUNT_SW_DUMMY, NULL); + err = bpf__foreach_tev(obj, add_bpf_event, ¶m); + if (err) { + snprintf(errbuf, sizeof(errbuf), + "Attach events in BPF object failed"); + goto errout; + } + + return 0; errout: data->error->help = strdup("(add -v to see detail)"); data->error->str = strdup(errbuf); -- 1.8.3.4 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
