perf tools: display the new PERF_RECORD_BPF_METADATA event

Here's some example "perf script -D" output for the new event type. The
": unhandled!" message is from tool.c, analogous to other behavior there.
I've elided some rows with all NUL characters for brevity, and I wrapped
one of the >75-column lines to fit in the commit guidelines.

0x50fc8@perf.data [0x260]: event: 84
.
. ... raw event: size 608 bytes
.  0000:  54 00 00 00 00 00 60 02 62 70 66 5f 70 72 6f 67  T.....`.bpf_prog
.  0010:  5f 31 65 30 61 32 65 33 36 36 65 35 36 66 31 61  _1e0a2e366e56f1a
.  0020:  32 5f 70 65 72 66 5f 73 61 6d 70 6c 65 5f 66 69  2_perf_sample_fi
.  0030:  6c 74 65 72 00 00 00 00 00 00 00 00 00 00 00 00  lter............
.  0040:  00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00  ................
[...]
.  0110:  74 65 73 74 5f 76 61 6c 75 65 00 00 00 00 00 00  test_value......
.  0120:  00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00  ................
[...]
.  0150:  34 32 00 00 00 00 00 00 00 00 00 00 00 00 00 00  42..............
.  0160:  00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00  ................
[...]

0 0x50fc8 [0x260]: PERF_RECORD_BPF_METADATA \
      prog bpf_prog_1e0a2e366e56f1a2_perf_sample_filter
  entry 0:           test_value = 42
: unhandled!

Signed-off-by: Blake Jones <blakejones@google.com>
Link: https://lore.kernel.org/r/20250612194939.162730-5-blakejones@google.com
Signed-off-by: Namhyung Kim <namhyung@kernel.org>

tools/perf/builtin-inject.c

@@ -2530,6 +2530,7 @@ int cmd_inject(int argc, const char **argv)
 	inject.tool.finished_init	= perf_event__repipe_op2_synth;
 	inject.tool.compressed		= perf_event__repipe_op4_synth;
 	inject.tool.auxtrace		= perf_event__repipe_auxtrace;
+	inject.tool.bpf_metadata	= perf_event__repipe_op2_synth;
 	inject.tool.dont_split_sample_group = true;
 	inject.session = __perf_session__new(&data, &inject.tool,
 					     /*trace_event_repipe=*/inject.output.is_pipe);

tools/perf/builtin-script.c

@@ -38,6 +38,7 @@
 #include "print_insn.h"
 #include "archinsn.h"
 #include <linux/bitmap.h>
+#include <linux/compiler.h>
 #include <linux/kernel.h>
 #include <linux/stringify.h>
 #include <linux/time64.h>
@@ -50,6 +51,7 @@
 #include <errno.h>
 #include <inttypes.h>
 #include <signal.h>
+#include <stdio.h>
 #include <sys/param.h>
 #include <sys/types.h>
 #include <sys/stat.h>
@@ -2755,6 +2757,14 @@ process_bpf_events(const struct perf_tool *tool __maybe_unused,
 			   sample->tid);
 }
 
+static int
+process_bpf_metadata_event(struct perf_session *session __maybe_unused,
+			   union perf_event *event)
+{
+	perf_event__fprintf(event, NULL, stdout);
+	return 0;
+}
+
 static int process_text_poke_events(const struct perf_tool *tool,
 				    union perf_event *event,
 				    struct perf_sample *sample,
@@ -2877,8 +2887,9 @@ static int __cmd_script(struct perf_script *script)
 		script->tool.finished_round = process_finished_round_event;
 	}
 	if (script->show_bpf_events) {
-		script->tool.ksymbol = process_bpf_events;
-		script->tool.bpf     = process_bpf_events;
+		script->tool.ksymbol	  = process_bpf_events;
+		script->tool.bpf	  = process_bpf_events;
+		script->tool.bpf_metadata = process_bpf_metadata_event;
 	}
 	if (script->show_text_poke_events) {
 		script->tool.ksymbol   = process_bpf_events;

tools/perf/util/event.c

@@ -1,9 +1,12 @@
 #include <errno.h>
 #include <fcntl.h>
 #include <inttypes.h>
+#include <linux/compiler.h>
 #include <linux/kernel.h>
 #include <linux/types.h>
 #include <perf/cpumap.h>
+#include <perf/event.h>
+#include <stdio.h>
 #include <sys/types.h>
 #include <sys/stat.h>
 #include <unistd.h>
@@ -78,6 +81,7 @@ static const char *perf_event__names[] = {
 	[PERF_RECORD_COMPRESSED]		= "COMPRESSED",
 	[PERF_RECORD_FINISHED_INIT]		= "FINISHED_INIT",
 	[PERF_RECORD_COMPRESSED2]		= "COMPRESSED2",
+	[PERF_RECORD_BPF_METADATA]		= "BPF_METADATA",
 };
 
 const char *perf_event__name(unsigned int id)
@@ -505,6 +509,20 @@ size_t perf_event__fprintf_bpf(union perf_event *event, FILE *fp)
 		       event->bpf.type, event->bpf.flags, event->bpf.id);
 }
 
+size_t perf_event__fprintf_bpf_metadata(union perf_event *event, FILE *fp)
+{
+	struct perf_record_bpf_metadata *metadata = &event->bpf_metadata;
+	size_t ret;
+
+	ret = fprintf(fp, " prog %s\n", metadata->prog_name);
+	for (__u32 i = 0; i < metadata->nr_entries; i++) {
+		ret += fprintf(fp, "  entry %d: %20s = %s\n", i,
+			       metadata->entries[i].key,
+			       metadata->entries[i].value);
+	}
+	return ret;
+}
+
 static int text_poke_printer(enum binary_printer_ops op, unsigned int val,
 			     void *extra, FILE *fp)
 {
@@ -602,6 +620,9 @@ size_t perf_event__fprintf(union perf_event *event, struct machine *machine, FIL
 	case PERF_RECORD_AUX_OUTPUT_HW_ID:
 		ret += perf_event__fprintf_aux_output_hw_id(event, fp);
 		break;
+	case PERF_RECORD_BPF_METADATA:
+		ret += perf_event__fprintf_bpf_metadata(event, fp);
+		break;
 	default:
 		ret += fprintf(fp, "\n");
 	}

tools/perf/util/event.h

@@ -370,6 +370,7 @@ size_t perf_event__fprintf_namespaces(union perf_event *event, FILE *fp);
 size_t perf_event__fprintf_cgroup(union perf_event *event, FILE *fp);
 size_t perf_event__fprintf_ksymbol(union perf_event *event, FILE *fp);
 size_t perf_event__fprintf_bpf(union perf_event *event, FILE *fp);
+size_t perf_event__fprintf_bpf_metadata(union perf_event *event, FILE *fp);
 size_t perf_event__fprintf_text_poke(union perf_event *event, struct machine *machine,FILE *fp);
 size_t perf_event__fprintf(union perf_event *event, struct machine *machine, FILE *fp);
 

tools/perf/util/session.c

@@ -12,6 +12,7 @@
 #include <sys/types.h>
 #include <sys/mman.h>
 #include <perf/cpumap.h>
+#include <perf/event.h>
 
 #include "map_symbol.h"
 #include "branch.h"
@@ -1491,6 +1492,9 @@ static s64 perf_session__process_user_event(struct perf_session *session,
 	case PERF_RECORD_FINISHED_INIT:
 		err = tool->finished_init(session, event);
 		break;
+	case PERF_RECORD_BPF_METADATA:
+		err = tool->bpf_metadata(session, event);
+		break;
 	default:
 		err = -EINVAL;
 		break;

tools/perf/util/tool.c

@@ -1,12 +1,15 @@
 // SPDX-License-Identifier: GPL-2.0
 #include "data.h"
 #include "debug.h"
+#include "event.h"
 #include "header.h"
 #include "session.h"
 #include "stat.h"
 #include "tool.h"
 #include "tsc.h"
+#include <linux/compiler.h>
 #include <sys/mman.h>
+#include <stddef.h>
 #include <unistd.h>
 
 #ifdef HAVE_ZSTD_SUPPORT
@@ -237,6 +240,16 @@ static int perf_session__process_compressed_event_stub(struct perf_session *sess
 	return 0;
 }
 
+static int perf_event__process_bpf_metadata_stub(struct perf_session *perf_session __maybe_unused,
+						 union perf_event *event)
+{
+	if (dump_trace)
+		perf_event__fprintf_bpf_metadata(event, stdout);
+
+	dump_printf(": unhandled!\n");
+	return 0;
+}
+
 void perf_tool__init(struct perf_tool *tool, bool ordered_events)
 {
 	tool->ordered_events = ordered_events;
@@ -293,6 +306,7 @@ void perf_tool__init(struct perf_tool *tool, bool ordered_events)
 	tool->compressed = perf_session__process_compressed_event_stub;
 #endif
 	tool->finished_init = process_event_op2_stub;
+	tool->bpf_metadata = perf_event__process_bpf_metadata_stub;
 }
 
 bool perf_tool__compressed_is_stub(const struct perf_tool *tool)

tools/perf/util/tool.h

@@ -77,7 +77,8 @@ struct perf_tool {
 			stat,
 			stat_round,
 			feature,
-			finished_init;
+			finished_init,
+			bpf_metadata;
 	event_op4	compressed;
 	event_op3	auxtrace;
 	bool		ordered_events;