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-rw-r--r--tools/perf/util/bpf-loader.c222
-rw-r--r--tools/perf/util/bpf-loader.h30
-rw-r--r--tools/perf/util/parse-events.c17
3 files changed, 268 insertions, 1 deletions
diff --git a/tools/perf/util/bpf-loader.c b/tools/perf/util/bpf-loader.c
index ab56073c5d6e..56f6fe8cf318 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 f402d7c8c288..b819622dc7ce 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 a9e1d79d17d7..10a946779f46 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.
generated by cgit v1.2.3 (git 2.39.1) at 2024-12-30 15:45:15 +0100