perf inject: Fix leader sampling inserting additional samples

The processing of leader samples would turn an individual sample with
a group of read values into multiple samples. 'perf inject' would pass
through the additional samples increasing the output data file size:

  $ perf record -g -e "{instructions,cycles}:S" -o perf.orig.data true
  $ perf script -D -i perf.orig.data | sed -e 's/perf.orig.data/perf.data/g' > orig.txt
  $ perf inject -i perf.orig.data -o perf.new.data
  $ perf script -D -i perf.new.data | sed -e 's/perf.new.data/perf.data/g' > new.txt
  $ diff -u orig.txt new.txt
  --- orig.txt    2024-07-29 14:29:40.606576769 -0700
  +++ new.txt     2024-07-29 14:30:04.142737434 -0700
  ...
  -0xc550@perf.data [0x30]: event: 3
  +0xc550@perf.data [0xd0]: event: 9
  +.
  +. ... raw event: size 208 bytes
  +.  0000:  09 00 00 00 01 00 d0 00 fc 72 01 86 ff ff ff ff  .........r......
  +.  0010:  74 7d 2c 00 74 7d 2c 00 fb c3 79 f9 ba d5 05 00  t},.t},...y.....
  +.  0020:  e6 cb 1a 00 00 00 00 00 01 00 00 00 00 00 00 00  ................
  +.  0030:  02 00 00 00 00 00 00 00 76 01 00 00 00 00 00 00  ........v.......
  +.  0040:  e6 cb 1a 00 00 00 00 00 00 00 00 00 00 00 00 00  ................
  +.  0050:  62 18 00 00 00 00 00 00 f6 cb 1a 00 00 00 00 00  b...............
  +.  0060:  00 00 00 00 00 00 00 00 0c 00 00 00 00 00 00 00  ................
  +.  0070:  80 ff ff ff ff ff ff ff fc 72 01 86 ff ff ff ff  .........r......
  +.  0080:  f3 0e 6e 85 ff ff ff ff 0c cb 7f 85 ff ff ff ff  ..n.............
  +.  0090:  bc f2 87 85 ff ff ff ff 44 af 7f 85 ff ff ff ff  ........D.......
  +.  00a0:  bd be 7f 85 ff ff ff ff 26 d0 7f 85 ff ff ff ff  ........&.......
  +.  00b0:  6d a4 ff 85 ff ff ff ff ea 00 20 86 ff ff ff ff  m......... .....
  +.  00c0:  00 fe ff ff ff ff ff ff 57 14 4f 43 fc 7e 00 00  ........W.OC.~..
  +
  +1642373909693435 0xc550 [0xd0]: PERF_RECORD_SAMPLE(IP, 0x1): 2915700/2915700: 0xffffffff860172fc period: 1 addr: 0
  +... FP chain: nr:12
  +.....  0: ffffffffffffff80
  +.....  1: ffffffff860172fc
  +.....  2: ffffffff856e0ef3
  +.....  3: ffffffff857fcb0c
  +.....  4: ffffffff8587f2bc
  +.....  5: ffffffff857faf44
  +.....  6: ffffffff857fbebd
  +.....  7: ffffffff857fd026
  +.....  8: ffffffff85ffa46d
  +.....  9: ffffffff862000ea
  +..... 10: fffffffffffffe00
  +..... 11: 00007efc434f1457
  +... sample_read:
  +.... group nr 2
  +..... id 00000000001acbe6, value 0000000000000176, lost 0
  +..... id 00000000001acbf6, value 0000000000001862, lost 0
  +
  +0xc620@perf.data [0x30]: event: 3
  ...

This behavior is incorrect as in the case above 'perf inject' should
have done nothing. Fix this behavior by disabling separating samples
for a tool that requests it. Only request this for `perf inject` so as
to not affect other perf tools. With the patch and the test above
there are no differences between the orig.txt and new.txt.

Fixes: e4caec0d ("perf evsel: Add PERF_SAMPLE_READ sample related processing")
Signed-off-by: Ian Rogers <irogers@google.com>
Acked-by: Namhyung Kim <namhyung@kernel.org>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Kan Liang <kan.liang@linux.intel.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: https://lore.kernel.org/r/20240729220620.2957754-1-irogers@google.comSigned-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

tools/perf/builtin-inject.c

@@ -2204,6 +2204,7 @@ int cmd_inject(int argc, const char **argv)
 			.finished_init	= perf_event__repipe_op2_synth,
 			.compressed	= perf_event__repipe_op4_synth,
 			.auxtrace	= perf_event__repipe_auxtrace,
+			.dont_split_sample_group = true,
 		},
 		.input_name  = "-",
 		.samples = LIST_HEAD_INIT(inject.samples),

tools/perf/util/session.c

@@ -1513,6 +1513,9 @@ static int deliver_sample_group(struct evlist *evlist,
 	int ret = -EINVAL;
 	struct sample_read_value *v = sample->read.group.values;
 
+	if (tool->dont_split_sample_group)
+		return deliver_sample_value(evlist, tool, event, sample, v, machine);
+
 	sample_read_group__for_each(v, sample->read.group.nr, read_format) {
 		ret = deliver_sample_value(evlist, tool, event, sample, v,
 					   machine);

tools/perf/util/tool.h

@@ -85,6 +85,7 @@ struct perf_tool {
 	bool		namespace_events;
 	bool		cgroup_events;
 	bool		no_warn;
+	bool		dont_split_sample_group;
 	enum show_feature_header show_feat_hdr;
 };