diff options
| -rw-r--r-- | tools/perf/util/bpf-loader.c | 222 | ||||
| -rw-r--r-- | tools/perf/util/bpf-loader.h | 30 | ||||
| -rw-r--r-- | tools/perf/util/parse-events.c | 17 |
3 files changed, 268 insertions, 1 deletions
diff --git a/tools/perf/util/bpf-loader.c b/tools/perf/util/bpf-loader.c index ab56073..56f6fe8 100644 --- a/tools/perf/util/bpf-loader.c +++ b/tools/perf/util/bpf-loader.c @@ -10,6 +10,8 @@ #include "perf.h" #include "debug.h" #include "bpf-loader.h" +#include "probe-event.h" +#include "probe-finder.h" // for MAX_PROBES #define DEFINE_PRINT_FN(name, level) \ static int libbpf_##name(const char *fmt, ...) \ @@ -27,6 +29,10 @@ DEFINE_PRINT_FN(warning, 0) DEFINE_PRINT_FN(info, 0) DEFINE_PRINT_FN(debug, 1) +struct bpf_prog_priv { + struct perf_probe_event pev; +}; + struct bpf_object *bpf__prepare_load(const char *filename) { struct bpf_object *obj; @@ -52,6 +58,220 @@ void bpf__clear(void) { struct bpf_object *obj, *tmp; - bpf_object__for_each_safe(obj, tmp) + bpf_object__for_each_safe(obj, tmp) { + bpf__unprobe(obj); bpf_object__close(obj); + } +} + +static void +bpf_prog_priv__clear(struct bpf_program *prog __maybe_unused, + void *_priv) +{ + struct bpf_prog_priv *priv = _priv; + + cleanup_perf_probe_events(&priv->pev, 1); + free(priv); +} + +static int +config_bpf_program(struct bpf_program *prog) +{ + struct perf_probe_event *pev = NULL; + struct bpf_prog_priv *priv = NULL; + const char *config_str; + int err; + + config_str = bpf_program__title(prog, false); + if (!config_str) { + pr_debug("bpf: unable to get title for program\n"); + return -EINVAL; + } + + priv = calloc(sizeof(*priv), 1); + if (!priv) { + pr_debug("bpf: failed to alloc priv\n"); + return -ENOMEM; + } + pev = &priv->pev; + + pr_debug("bpf: config program '%s'\n", config_str); + err = parse_perf_probe_command(config_str, pev); + if (err < 0) { + pr_debug("bpf: '%s' is not a valid config string\n", + config_str); + err = -EINVAL; + goto errout; + } + + if (pev->group && strcmp(pev->group, PERF_BPF_PROBE_GROUP)) { + pr_debug("bpf: '%s': group for event is set and not '%s'.\n", + config_str, PERF_BPF_PROBE_GROUP); + err = -EINVAL; + goto errout; + } else if (!pev->group) + pev->group = strdup(PERF_BPF_PROBE_GROUP); + + if (!pev->group) { + pr_debug("bpf: strdup failed\n"); + err = -ENOMEM; + goto errout; + } + + if (!pev->event) { + pr_debug("bpf: '%s': event name is missing\n", + config_str); + err = -EINVAL; + goto errout; + } + pr_debug("bpf: config '%s' is ok\n", config_str); + + err = bpf_program__set_private(prog, priv, bpf_prog_priv__clear); + if (err) { + pr_debug("Failed to set priv for program '%s'\n", config_str); + goto errout; + } + + return 0; + +errout: + if (pev) + clear_perf_probe_event(pev); + free(priv); + return err; +} + +static int bpf__prepare_probe(void) +{ + static int err = 0; + static bool initialized = false; + + /* + * Make err static, so if init failed the first, bpf__prepare_probe() + * fails each time without calling init_probe_symbol_maps multiple + * times. + */ + if (initialized) + return err; + + initialized = true; + err = init_probe_symbol_maps(false); + if (err < 0) + pr_debug("Failed to init_probe_symbol_maps\n"); + probe_conf.max_probes = MAX_PROBES; + return err; +} + +int bpf__probe(struct bpf_object *obj) +{ + int err = 0; + struct bpf_program *prog; + struct bpf_prog_priv *priv; + struct perf_probe_event *pev; + + err = bpf__prepare_probe(); + if (err) { + pr_debug("bpf__prepare_probe failed\n"); + return err; + } + + bpf_object__for_each_program(prog, obj) { + err = config_bpf_program(prog); + if (err) + goto out; + + err = bpf_program__get_private(prog, (void **)&priv); + if (err || !priv) + goto out; + pev = &priv->pev; + + err = convert_perf_probe_events(pev, 1); + if (err < 0) { + pr_debug("bpf_probe: failed to convert perf probe events"); + goto out; + } + + err = apply_perf_probe_events(pev, 1); + if (err < 0) { + pr_debug("bpf_probe: failed to apply perf probe events"); + goto out; + } + } +out: + return err < 0 ? err : 0; +} + +#define EVENTS_WRITE_BUFSIZE 4096 +int bpf__unprobe(struct bpf_object *obj) +{ + int err, ret = 0; + struct bpf_program *prog; + struct bpf_prog_priv *priv; + + bpf_object__for_each_program(prog, obj) { + int i; + + err = bpf_program__get_private(prog, (void **)&priv); + if (err || !priv) + continue; + + for (i = 0; i < priv->pev.ntevs; i++) { + struct probe_trace_event *tev = &priv->pev.tevs[i]; + char name_buf[EVENTS_WRITE_BUFSIZE]; + struct strfilter *delfilter; + + snprintf(name_buf, EVENTS_WRITE_BUFSIZE, + "%s:%s", tev->group, tev->event); + name_buf[EVENTS_WRITE_BUFSIZE - 1] = '\0'; + + delfilter = strfilter__new(name_buf, NULL); + if (!delfilter) { + pr_debug("Failed to create filter for unprobing\n"); + ret = -ENOMEM; + continue; + } + + err = del_perf_probe_events(delfilter); + strfilter__delete(delfilter); + if (err) { + pr_debug("Failed to delete %s\n", name_buf); + ret = err; + continue; + } + } + } + return ret; +} + +#define bpf__strerror_head(err, buf, size) \ + char sbuf[STRERR_BUFSIZE], *emsg;\ + if (!size)\ + return 0;\ + if (err < 0)\ + err = -err;\ + emsg = strerror_r(err, sbuf, sizeof(sbuf));\ + switch (err) {\ + default:\ + scnprintf(buf, size, "%s", emsg);\ + break; + +#define bpf__strerror_entry(val, fmt...)\ + case val: {\ + scnprintf(buf, size, fmt);\ + break;\ + } + +#define bpf__strerror_end(buf, size)\ + }\ + buf[size - 1] = '\0'; + +int bpf__strerror_probe(struct bpf_object *obj __maybe_unused, + int err, char *buf, size_t size) +{ + bpf__strerror_head(err, buf, size); + bpf__strerror_entry(EEXIST, "Probe point exist. Try use 'perf probe -d \"*\"'"); + bpf__strerror_entry(EPERM, "You need to be root, and /proc/sys/kernel/kptr_restrict should be 0\n"); + bpf__strerror_entry(ENOENT, "You need to check probing points in BPF file\n"); + bpf__strerror_end(buf, size); + return 0; } diff --git a/tools/perf/util/bpf-loader.h b/tools/perf/util/bpf-loader.h index f402d7c..b819622 100644 --- a/tools/perf/util/bpf-loader.h +++ b/tools/perf/util/bpf-loader.h @@ -11,11 +11,18 @@ #include "debug.h" struct bpf_object; +#define PERF_BPF_PROBE_GROUP "perf_bpf_probe" #ifdef HAVE_LIBBPF_SUPPORT struct bpf_object *bpf__prepare_load(const char *filename); void bpf__clear(void); + +int bpf__probe(struct bpf_object *obj); +int bpf__unprobe(struct bpf_object *obj); +int bpf__strerror_probe(struct bpf_object *obj, int err, + char *buf, size_t size); + #else static inline struct bpf_object * bpf__prepare_load(const char *filename __maybe_unused) @@ -25,5 +32,28 @@ bpf__prepare_load(const char *filename __maybe_unused) } static inline void bpf__clear(void) { } + +static inline int bpf__probe(struct bpf_object *obj __maybe_unused) { return 0;} +static inline int bpf__unprobe(struct bpf_object *obj __maybe_unused) { return 0;} + +static inline int +__bpf_strerror(char *buf, size_t size) +{ + if (!size) + return 0; + strncpy(buf, + "ERROR: eBPF object loading is disabled during compiling.\n", + size); + buf[size - 1] = '\0'; + return 0; +} + +static inline int +bpf__strerror_probe(struct bpf_object *obj __maybe_unused, + int err __maybe_unused, + char *buf, size_t size) +{ + return __bpf_strerror(buf, size); +} #endif #endif diff --git a/tools/perf/util/parse-events.c b/tools/perf/util/parse-events.c index a9e1d79..10a9467 100644 --- a/tools/perf/util/parse-events.c +++ b/tools/perf/util/parse-events.c @@ -536,6 +536,7 @@ int parse_events_load_bpf_obj(struct parse_events_evlist *data, { int err; char errbuf[BUFSIZ]; + static bool registered_unprobe_atexit = false; if (IS_ERR(obj) || !obj) { snprintf(errbuf, sizeof(errbuf), @@ -545,6 +546,22 @@ int parse_events_load_bpf_obj(struct parse_events_evlist *data, } /* + * Register atexit handler before calling bpf__probe() so + * bpf__probe() don't need to unprobe probe points its already + * created when failure. + */ + if (!registered_unprobe_atexit) { + atexit(bpf__clear); + registered_unprobe_atexit = true; + } + + err = bpf__probe(obj); + if (err) { + bpf__strerror_probe(obj, err, errbuf, sizeof(errbuf)); + goto errout; + } + + /* * Temporary add a dummy event here so we can check whether * basic bpf loader works. Following patches will replace * dummy event by useful evsels. |