perf test: Support the ins_lat check in the X86 specific test

The ins_lat of PERF_SAMPLE_WEIGHT_STRUCT stands for the instruction
latency, which is only available for X86. Add a X86 specific test for
the ins_lat and PERF_SAMPLE_WEIGHT_STRUCT type.

The test__x86_sample_parsing() uses the same way as the
test__sample_parsing() to verify a sample type. Since the ins_lat and
PERF_SAMPLE_WEIGHT_STRUCT are the only X86 specific sample type for now,
the test__x86_sample_parsing() only verify the PERF_SAMPLE_WEIGHT_STRUCT
type. Other sample types are still verified in the generic test.

  $ perf test 77 -v
  77: x86 Sample parsing                                              :
  --- start ---
  test child forked, pid 102370
  test child finished with 0
  ---- end ----
  x86 Sample parsing: Ok

Signed-off-by: Kan Liang <kan.liang@linux.intel.com>
Cc: Athira Jajeev <atrajeev@linux.vnet.ibm.com>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: Sumanth Korikkar <sumanthk@linux.ibm.com>
Cc: Sven Schnelle <svens@linux.ibm.com>
Cc: Thomas Richter <tmricht@linux.ibm.com>
Cc: Vasily Gorbik <gor@linux.ibm.com>
Link: http://lore.kernel.org/lkml/1614787285-104151-2-git-send-email-kan.liang@linux.intel.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

tools/perf/arch/x86/include/arch-tests.h

@@ -10,6 +10,7 @@ int test__rdpmc(struct test *test __maybe_unused, int subtest);
 int test__insn_x86(struct test *test __maybe_unused, int subtest);
 int test__intel_pt_pkt_decoder(struct test *test, int subtest);
 int test__bp_modify(struct test *test, int subtest);
+int test__x86_sample_parsing(struct test *test, int subtest);
 
 #ifdef HAVE_DWARF_UNWIND_SUPPORT
 struct thread;

tools/perf/arch/x86/tests/Build

@@ -3,5 +3,6 @@ perf-$(CONFIG_DWARF_UNWIND) += dwarf-unwind.o
 
 perf-y += arch-tests.o
 perf-y += rdpmc.o
+perf-y += sample-parsing.o
 perf-$(CONFIG_AUXTRACE) += insn-x86.o intel-pt-pkt-decoder-test.o
 perf-$(CONFIG_X86_64) += bp-modify.o

tools/perf/arch/x86/tests/arch-tests.c

@@ -30,6 +30,10 @@ struct test arch_tests[] = {
 		.func = test__bp_modify,
 	},
 #endif
+	{
+		.desc = "x86 Sample parsing",
+		.func = test__x86_sample_parsing,
+	},
 	{
 		.func = NULL,
 	},

tools/perf/arch/x86/tests/sample-parsing.c

@@ -0,0 +1,121 @@
+// SPDX-License-Identifier: GPL-2.0-only
+#include <stdbool.h>
+#include <inttypes.h>
+#include <stdlib.h>
+#include <string.h>
+#include <linux/bitops.h>
+#include <linux/kernel.h>
+#include <linux/types.h>
+
+#include "event.h"
+#include "evsel.h"
+#include "debug.h"
+#include "util/synthetic-events.h"
+
+#include "tests/tests.h"
+#include "arch-tests.h"
+
+#define COMP(m) do {					\
+	if (s1->m != s2->m) {				\
+		pr_debug("Samples differ at '"#m"'\n");	\
+		return false;				\
+	}						\
+} while (0)
+
+static bool samples_same(const struct perf_sample *s1,
+			 const struct perf_sample *s2,
+			 u64 type)
+{
+	if (type & PERF_SAMPLE_WEIGHT_STRUCT)
+		COMP(ins_lat);
+
+	return true;
+}
+
+static int do_test(u64 sample_type)
+{
+	struct evsel evsel = {
+		.needs_swap = false,
+		.core = {
+			. attr = {
+				.sample_type = sample_type,
+				.read_format = 0,
+			},
+		},
+	};
+	union perf_event *event;
+	struct perf_sample sample = {
+		.weight		= 101,
+		.ins_lat        = 102,
+	};
+	struct perf_sample sample_out;
+	size_t i, sz, bufsz;
+	int err, ret = -1;
+
+	sz = perf_event__sample_event_size(&sample, sample_type, 0);
+	bufsz = sz + 4096; /* Add a bit for overrun checking */
+	event = malloc(bufsz);
+	if (!event) {
+		pr_debug("malloc failed\n");
+		return -1;
+	}
+
+	memset(event, 0xff, bufsz);
+	event->header.type = PERF_RECORD_SAMPLE;
+	event->header.misc = 0;
+	event->header.size = sz;
+
+	err = perf_event__synthesize_sample(event, sample_type, 0, &sample);
+	if (err) {
+		pr_debug("%s failed for sample_type %#"PRIx64", error %d\n",
+			 "perf_event__synthesize_sample", sample_type, err);
+		goto out_free;
+	}
+
+	/* The data does not contain 0xff so we use that to check the size */
+	for (i = bufsz; i > 0; i--) {
+		if (*(i - 1 + (u8 *)event) != 0xff)
+			break;
+	}
+	if (i != sz) {
+		pr_debug("Event size mismatch: actual %zu vs expected %zu\n",
+			 i, sz);
+		goto out_free;
+	}
+
+	evsel.sample_size = __evsel__sample_size(sample_type);
+
+	err = evsel__parse_sample(&evsel, event, &sample_out);
+	if (err) {
+		pr_debug("%s failed for sample_type %#"PRIx64", error %d\n",
+			 "evsel__parse_sample", sample_type, err);
+		goto out_free;
+	}
+
+	if (!samples_same(&sample, &sample_out, sample_type)) {
+		pr_debug("parsing failed for sample_type %#"PRIx64"\n",
+			 sample_type);
+		goto out_free;
+	}
+
+	ret = 0;
+out_free:
+	free(event);
+
+	return ret;
+}
+
+/**
+ * test__x86_sample_parsing - test X86 specific sample parsing
+ *
+ * This function implements a test that synthesizes a sample event, parses it
+ * and then checks that the parsed sample matches the original sample. If the
+ * test passes %0 is returned, otherwise %-1 is returned.
+ *
+ * For now, the PERF_SAMPLE_WEIGHT_STRUCT is the only X86 specific sample type.
+ * The test only checks the PERF_SAMPLE_WEIGHT_STRUCT type.
+ */
+int test__x86_sample_parsing(struct test *test __maybe_unused, int subtest __maybe_unused)
+{
+	return do_test(PERF_SAMPLE_WEIGHT_STRUCT);
+}