19 files changed, 425 insertions, 17 deletions

diff --git a/tools/perf/tests/Build b/tools/perf/tests/Build
index 1ba628e..66a2898 100644
--- a/tools/perf/tests/Build
+++ b/tools/perf/tests/Build
@@ -37,6 +37,8 @@ perf-y += topology.o
 perf-y += cpumap.o
 perf-y += stat.o
 perf-y += event_update.o
+perf-y += event-times.o
+perf-y += backward-ring-buffer.o
 
 $(OUTPUT)tests/llvm-src-base.c: tests/bpf-script-example.c tests/Build
 	$(call rule_mkdir)
diff --git a/tools/perf/tests/backward-ring-buffer.c b/tools/perf/tests/backward-ring-buffer.c
new file mode 100644
index 0000000..d9ba991
--- /dev/null
+++ b/tools/perf/tests/backward-ring-buffer.c
@@ -0,0 +1,151 @@
+/*
+ * Test backward bit in event attribute, read ring buffer from end to
+ * beginning
+ */
+
+#include <perf.h>
+#include <evlist.h>
+#include <sys/prctl.h>
+#include "tests.h"
+#include "debug.h"
+
+#define NR_ITERS 111
+
+static void testcase(void)
+{
+	int i;
+
+	for (i = 0; i < NR_ITERS; i++) {
+		char proc_name[10];
+
+		snprintf(proc_name, sizeof(proc_name), "p:%d\n", i);
+		prctl(PR_SET_NAME, proc_name);
+	}
+}
+
+static int count_samples(struct perf_evlist *evlist, int *sample_count,
+			 int *comm_count)
+{
+	int i;
+
+	for (i = 0; i < evlist->nr_mmaps; i++) {
+		union perf_event *event;
+
+		perf_evlist__mmap_read_catchup(evlist, i);
+		while ((event = perf_evlist__mmap_read_backward(evlist, i)) != NULL) {
+			const u32 type = event->header.type;
+
+			switch (type) {
+			case PERF_RECORD_SAMPLE:
+				(*sample_count)++;
+				break;
+			case PERF_RECORD_COMM:
+				(*comm_count)++;
+				break;
+			default:
+				pr_err("Unexpected record of type %d\n", type);
+				return TEST_FAIL;
+			}
+		}
+	}
+	return TEST_OK;
+}
+
+static int do_test(struct perf_evlist *evlist, int mmap_pages,
+		   int *sample_count, int *comm_count)
+{
+	int err;
+	char sbuf[STRERR_BUFSIZE];
+
+	err = perf_evlist__mmap(evlist, mmap_pages, true);
+	if (err < 0) {
+		pr_debug("perf_evlist__mmap: %s\n",
+			 strerror_r(errno, sbuf, sizeof(sbuf)));
+		return TEST_FAIL;
+	}
+
+	perf_evlist__enable(evlist);
+	testcase();
+	perf_evlist__disable(evlist);
+
+	err = count_samples(evlist, sample_count, comm_count);
+	perf_evlist__munmap(evlist);
+	return err;
+}
+
+
+int test__backward_ring_buffer(int subtest __maybe_unused)
+{
+	int ret = TEST_SKIP, err, sample_count = 0, comm_count = 0;
+	char pid[16], sbuf[STRERR_BUFSIZE];
+	struct perf_evlist *evlist;
+	struct perf_evsel *evsel __maybe_unused;
+	struct parse_events_error parse_error;
+	struct record_opts opts = {
+		.target = {
+			.uid = UINT_MAX,
+			.uses_mmap = true,
+		},
+		.freq	      = 0,
+		.mmap_pages   = 256,
+		.default_interval = 1,
+	};
+
+	snprintf(pid, sizeof(pid), "%d", getpid());
+	pid[sizeof(pid) - 1] = '\0';
+	opts.target.tid = opts.target.pid = pid;
+
+	evlist = perf_evlist__new();
+	if (!evlist) {
+		pr_debug("No ehough memory to create evlist\n");
+		return TEST_FAIL;
+	}
+
+	err = perf_evlist__create_maps(evlist, &opts.target);
+	if (err < 0) {
+		pr_debug("Not enough memory to create thread/cpu maps\n");
+		goto out_delete_evlist;
+	}
+
+	bzero(&parse_error, sizeof(parse_error));
+	err = parse_events(evlist, "syscalls:sys_enter_prctl", &parse_error);
+	if (err) {
+		pr_debug("Failed to parse tracepoint event, try use root\n");
+		ret = TEST_SKIP;
+		goto out_delete_evlist;
+	}
+
+	perf_evlist__config(evlist, &opts, NULL);
+
+	/* Set backward bit, ring buffer should be writing from end */
+	evlist__for_each(evlist, evsel)
+		evsel->attr.write_backward = 1;
+
+	err = perf_evlist__open(evlist);
+	if (err < 0) {
+		pr_debug("perf_evlist__open: %s\n",
+			 strerror_r(errno, sbuf, sizeof(sbuf)));
+		goto out_delete_evlist;
+	}
+
+	ret = TEST_FAIL;
+	err = do_test(evlist, opts.mmap_pages, &sample_count,
+		      &comm_count);
+	if (err != TEST_OK)
+		goto out_delete_evlist;
+
+	if ((sample_count != NR_ITERS) || (comm_count != NR_ITERS)) {
+		pr_err("Unexpected counter: sample_count=%d, comm_count=%d\n",
+		       sample_count, comm_count);
+		goto out_delete_evlist;
+	}
+
+	err = do_test(evlist, 1, &sample_count, &comm_count);
+	if (err != TEST_OK)
+		goto out_delete_evlist;
+
+	ret = TEST_OK;
+out_delete_evlist:
+	perf_evlist__delete(evlist);
+	return ret;
+}
diff --git a/tools/perf/tests/bpf.c b/tools/perf/tests/bpf.c
index 199501c..f31eed3 100644
--- a/tools/perf/tests/bpf.c
+++ b/tools/perf/tests/bpf.c
@@ -138,7 +138,7 @@ static int do_test(struct bpf_object *obj, int (*func)(void),
 	perf_evlist__splice_list_tail(evlist, &parse_evlist.list);
 	evlist->nr_groups = parse_evlist.nr_groups;
 
-	perf_evlist__config(evlist, &opts);
+	perf_evlist__config(evlist, &opts, NULL);
 
 	err = perf_evlist__open(evlist);
 	if (err < 0) {
diff --git a/tools/perf/tests/builtin-test.c b/tools/perf/tests/builtin-test.c
index f2b1dca..0e95c20 100644
--- a/tools/perf/tests/builtin-test.c
+++ b/tools/perf/tests/builtin-test.c
@@ -204,6 +204,14 @@ static struct test generic_tests[] = {
 		.func = test__event_update,
 	},
 	{
+		.desc = "Test events times",
+		.func = test__event_times,
+	},
+	{
+		.desc = "Test backward reading from ring buffer",
+		.func = test__backward_ring_buffer,
+	},
+	{
 		.func = NULL,
 	},
 };
diff --git a/tools/perf/tests/code-reading.c b/tools/perf/tests/code-reading.c
index abd3f0e..68a69a1 100644
--- a/tools/perf/tests/code-reading.c
+++ b/tools/perf/tests/code-reading.c
@@ -532,7 +532,7 @@ static int do_test_code_reading(bool try_kcore)
 			goto out_put;
 		}
 
-		perf_evlist__config(evlist, &opts);
+		perf_evlist__config(evlist, &opts, NULL);
 
 		evsel = perf_evlist__first(evlist);
 
diff --git a/tools/perf/tests/dso-data.c b/tools/perf/tests/dso-data.c
index dc673ff..8cf0d9e 100644
--- a/tools/perf/tests/dso-data.c
+++ b/tools/perf/tests/dso-data.c
@@ -202,7 +202,7 @@ static int dsos__create(int cnt, int size)
 {
 	int i;
 
-	dsos = malloc(sizeof(dsos) * cnt);
+	dsos = malloc(sizeof(*dsos) * cnt);
 	TEST_ASSERT_VAL("failed to alloc dsos array", dsos);
 
 	for (i = 0; i < cnt; i++) {
diff --git a/tools/perf/tests/event-times.c b/tools/perf/tests/event-times.c
new file mode 100644
index 0000000..95fb744
--- /dev/null
+++ b/tools/perf/tests/event-times.c
@@ -0,0 +1,236 @@
+#include <linux/compiler.h>
+#include <string.h>
+#include "tests.h"
+#include "evlist.h"
+#include "evsel.h"
+#include "util.h"
+#include "debug.h"
+#include "thread_map.h"
+#include "target.h"
+
+static int attach__enable_on_exec(struct perf_evlist *evlist)
+{
+	struct perf_evsel *evsel = perf_evlist__last(evlist);
+	struct target target = {
+		.uid = UINT_MAX,
+	};
+	const char *argv[] = { "true", NULL, };
+	char sbuf[STRERR_BUFSIZE];
+	int err;
+
+	pr_debug("attaching to spawned child, enable on exec\n");
+
+	err = perf_evlist__create_maps(evlist, &target);
+	if (err < 0) {
+		pr_debug("Not enough memory to create thread/cpu maps\n");
+		return err;
+	}
+
+	err = perf_evlist__prepare_workload(evlist, &target, argv, false, NULL);
+	if (err < 0) {
+		pr_debug("Couldn't run the workload!\n");
+		return err;
+	}
+
+	evsel->attr.enable_on_exec = 1;
+
+	err = perf_evlist__open(evlist);
+	if (err < 0) {
+		pr_debug("perf_evlist__open: %s\n",
+			 strerror_r(errno, sbuf, sizeof(sbuf)));
+		return err;
+	}
+
+	return perf_evlist__start_workload(evlist) == 1 ? TEST_OK : TEST_FAIL;
+}
+
+static int detach__enable_on_exec(struct perf_evlist *evlist)
+{
+	waitpid(evlist->workload.pid, NULL, 0);
+	return 0;
+}
+
+static int attach__current_disabled(struct perf_evlist *evlist)
+{
+	struct perf_evsel *evsel = perf_evlist__last(evlist);
+	struct thread_map *threads;
+	int err;
+
+	pr_debug("attaching to current thread as disabled\n");
+
+	threads = thread_map__new(-1, getpid(), UINT_MAX);
+	if (threads == NULL) {
+		pr_debug("thread_map__new\n");
+		return -1;
+	}
+
+	evsel->attr.disabled = 1;
+
+	err = perf_evsel__open_per_thread(evsel, threads);
+	if (err) {
+		pr_debug("Failed to open event cpu-clock:u\n");
+		return err;
+	}
+
+	thread_map__put(threads);
+	return perf_evsel__enable(evsel) == 0 ? TEST_OK : TEST_FAIL;
+}
+
+static int attach__current_enabled(struct perf_evlist *evlist)
+{
+	struct perf_evsel *evsel = perf_evlist__last(evlist);
+	struct thread_map *threads;
+	int err;
+
+	pr_debug("attaching to current thread as enabled\n");
+
+	threads = thread_map__new(-1, getpid(), UINT_MAX);
+	if (threads == NULL) {
+		pr_debug("failed to call thread_map__new\n");
+		return -1;
+	}
+
+	err = perf_evsel__open_per_thread(evsel, threads);
+
+	thread_map__put(threads);
+	return err == 0 ? TEST_OK : TEST_FAIL;
+}
+
+static int detach__disable(struct perf_evlist *evlist)
+{
+	struct perf_evsel *evsel = perf_evlist__last(evlist);
+
+	return perf_evsel__enable(evsel);
+}
+
+static int attach__cpu_disabled(struct perf_evlist *evlist)
+{
+	struct perf_evsel *evsel = perf_evlist__last(evlist);
+	struct cpu_map *cpus;
+	int err;
+
+	pr_debug("attaching to CPU 0 as enabled\n");
+
+	cpus = cpu_map__new("0");
+	if (cpus == NULL) {
+		pr_debug("failed to call cpu_map__new\n");
+		return -1;
+	}
+
+	evsel->attr.disabled = 1;
+
+	err = perf_evsel__open_per_cpu(evsel, cpus);
+	if (err) {
+		if (err == -EACCES)
+			return TEST_SKIP;
+
+		pr_debug("Failed to open event cpu-clock:u\n");
+		return err;
+	}
+
+	cpu_map__put(cpus);
+	return perf_evsel__enable(evsel);
+}
+
+static int attach__cpu_enabled(struct perf_evlist *evlist)
+{
+	struct perf_evsel *evsel = perf_evlist__last(evlist);
+	struct cpu_map *cpus;
+	int err;
+
+	pr_debug("attaching to CPU 0 as enabled\n");
+
+	cpus = cpu_map__new("0");
+	if (cpus == NULL) {
+		pr_debug("failed to call cpu_map__new\n");
+		return -1;
+	}
+
+	err = perf_evsel__open_per_cpu(evsel, cpus);
+	if (err == -EACCES)
+		return TEST_SKIP;
+
+	cpu_map__put(cpus);
+	return err ? TEST_FAIL : TEST_OK;
+}
+
+static int test_times(int (attach)(struct perf_evlist *),
+		      int (detach)(struct perf_evlist *))
+{
+	struct perf_counts_values count;
+	struct perf_evlist *evlist = NULL;
+	struct perf_evsel *evsel;
+	int err = -1, i;
+
+	evlist = perf_evlist__new();
+	if (!evlist) {
+		pr_debug("failed to create event list\n");
+		goto out_err;
+	}
+
+	err = parse_events(evlist, "cpu-clock:u", NULL);
+	if (err) {
+		pr_debug("failed to parse event cpu-clock:u\n");
+		goto out_err;
+	}
+
+	evsel = perf_evlist__last(evlist);
+	evsel->attr.read_format |=
+		PERF_FORMAT_TOTAL_TIME_ENABLED |
+		PERF_FORMAT_TOTAL_TIME_RUNNING;
+
+	err = attach(evlist);
+	if (err == TEST_SKIP) {
+		pr_debug("  SKIP  : not enough rights\n");
+		return err;
+	}
+
+	TEST_ASSERT_VAL("failed to attach", !err);
+
+	for (i = 0; i < 100000000; i++) { }
+
+	TEST_ASSERT_VAL("failed to detach", !detach(evlist));
+
+	perf_evsel__read(evsel, 0, 0, &count);
+
+	err = !(count.ena == count.run);
+
+	pr_debug("  %s: ena %" PRIu64", run %" PRIu64"\n",
+		 !err ? "OK    " : "FAILED",
+		 count.ena, count.run);
+
+out_err:
+	if (evlist)
+		perf_evlist__delete(evlist);
+	return !err ? TEST_OK : TEST_FAIL;
+}
+
+/*
+ * This test creates software event 'cpu-clock'
+ * attaches it in several ways (explained below)
+ * and checks that enabled and running times
+ * match.
+ */
+int test__event_times(int subtest __maybe_unused)
+{
+	int err, ret = 0;
+
+#define _T(attach, detach)			\
+	err = test_times(attach, detach);	\
+	if (err && (ret == TEST_OK || ret == TEST_SKIP))	\
+		ret = err;
+
+	/* attach on newly spawned process after exec */
+	_T(attach__enable_on_exec,   detach__enable_on_exec)
+	/* attach on current process as enabled */
+	_T(attach__current_enabled,  detach__disable)
+	/* attach on current process as disabled */
+	_T(attach__current_disabled, detach__disable)
+	/* attach on cpu as disabled */
+	_T(attach__cpu_disabled,     detach__disable)
+	/* attach on cpu as enabled */
+	_T(attach__cpu_enabled,      detach__disable)
+
+#undef _T
+	return ret;
+}
diff --git a/tools/perf/tests/event_update.c b/tools/perf/tests/event_update.c
index 012eab5..63ecf21 100644
--- a/tools/perf/tests/event_update.c
+++ b/tools/perf/tests/event_update.c
@@ -30,7 +30,7 @@ static int process_event_scale(struct perf_tool *tool __maybe_unused,
 
 	TEST_ASSERT_VAL("wrong id", ev->id == 123);
 	TEST_ASSERT_VAL("wrong id", ev->type == PERF_EVENT_UPDATE__SCALE);
-	TEST_ASSERT_VAL("wrong scale", ev_data->scale = 0.123);
+	TEST_ASSERT_VAL("wrong scale", ev_data->scale == 0.123);
 	return 0;
 }
 
diff --git a/tools/perf/tests/hists_common.c b/tools/perf/tests/hists_common.c
index f55f4bd..6b21746 100644
--- a/tools/perf/tests/hists_common.c
+++ b/tools/perf/tests/hists_common.c
@@ -161,7 +161,7 @@ void print_hists_in(struct hists *hists)
 	struct rb_root *root;
 	struct rb_node *node;
 
-	if (sort__need_collapse)
+	if (hists__has(hists, need_collapse))
 		root = &hists->entries_collapsed;
 	else
 		root = hists->entries_in;
diff --git a/tools/perf/tests/hists_cumulate.c b/tools/perf/tests/hists_cumulate.c
index ed5aa9e..a9e3db3 100644
--- a/tools/perf/tests/hists_cumulate.c
+++ b/tools/perf/tests/hists_cumulate.c
@@ -101,7 +101,7 @@ static int add_hist_entries(struct hists *hists, struct machine *machine)
 		if (machine__resolve(machine, &al, &sample) < 0)
 			goto out;
 
-		if (hist_entry_iter__add(&iter, &al, PERF_MAX_STACK_DEPTH,
+		if (hist_entry_iter__add(&iter, &al, sysctl_perf_event_max_stack,
 					 NULL) < 0) {
 			addr_location__put(&al);
 			goto out;
@@ -126,7 +126,7 @@ static void del_hist_entries(struct hists *hists)
 	struct rb_root *root_out;
 	struct rb_node *node;
 
-	if (sort__need_collapse)
+	if (hists__has(hists, need_collapse))
 		root_in = &hists->entries_collapsed;
 	else
 		root_in = hists->entries_in;
diff --git a/tools/perf/tests/hists_filter.c b/tools/perf/tests/hists_filter.c
index b825d24..e846f8c 100644
--- a/tools/perf/tests/hists_filter.c
+++ b/tools/perf/tests/hists_filter.c
@@ -81,7 +81,7 @@ static int add_hist_entries(struct perf_evlist *evlist,
 
 			al.socket = fake_samples[i].socket;
 			if (hist_entry_iter__add(&iter, &al,
-						 PERF_MAX_STACK_DEPTH, NULL) < 0) {
+						 sysctl_perf_event_max_stack, NULL) < 0) {
 				addr_location__put(&al);
 				goto out;
 			}
diff --git a/tools/perf/tests/hists_link.c b/tools/perf/tests/hists_link.c
index 358324e..acf5a13 100644
--- a/tools/perf/tests/hists_link.c
+++ b/tools/perf/tests/hists_link.c
@@ -145,7 +145,7 @@ static int __validate_match(struct hists *hists)
 	/*
 	 * Only entries from fake_common_samples should have a pair.
 	 */
-	if (sort__need_collapse)
+	if (hists__has(hists, need_collapse))
 		root = &hists->entries_collapsed;
 	else
 		root = hists->entries_in;
@@ -197,7 +197,7 @@ static int __validate_link(struct hists *hists, int idx)
 	 * and some entries will have no pair.  However every entry
 	 * in other hists should have (dummy) pair.
 	 */
-	if (sort__need_collapse)
+	if (hists__has(hists, need_collapse))
 		root = &hists->entries_collapsed;
 	else
 		root = hists->entries_in;
diff --git a/tools/perf/tests/hists_output.c b/tools/perf/tests/hists_output.c
index d3556fb..63c5efa 100644
--- a/tools/perf/tests/hists_output.c
+++ b/tools/perf/tests/hists_output.c
@@ -67,7 +67,7 @@ static int add_hist_entries(struct hists *hists, struct machine *machine)
 		if (machine__resolve(machine, &al, &sample) < 0)
 			goto out;
 
-		if (hist_entry_iter__add(&iter, &al, PERF_MAX_STACK_DEPTH,
+		if (hist_entry_iter__add(&iter, &al, sysctl_perf_event_max_stack,
 					 NULL) < 0) {
 			addr_location__put(&al);
 			goto out;
@@ -92,7 +92,7 @@ static void del_hist_entries(struct hists *hists)
 	struct rb_root *root_out;
 	struct rb_node *node;
 
-	if (sort__need_collapse)
+	if (hists__has(hists, need_collapse))
 		root_in = &hists->entries_collapsed;
 	else
 		root_in = hists->entries_in;
diff --git a/tools/perf/tests/keep-tracking.c b/tools/perf/tests/keep-tracking.c
index ddb78fa..614e45a 100644
--- a/tools/perf/tests/keep-tracking.c
+++ b/tools/perf/tests/keep-tracking.c
@@ -80,7 +80,7 @@ int test__keep_tracking(int subtest __maybe_unused)
 	CHECK__(parse_events(evlist, "dummy:u", NULL));
 	CHECK__(parse_events(evlist, "cycles:u", NULL));
 
-	perf_evlist__config(evlist, &opts);
+	perf_evlist__config(evlist, &opts, NULL);
 
 	evsel = perf_evlist__first(evlist);
 
diff --git a/tools/perf/tests/openat-syscall-tp-fields.c b/tools/perf/tests/openat-syscall-tp-fields.c
index eb99a105..4344fe4 100644
--- a/tools/perf/tests/openat-syscall-tp-fields.c
+++ b/tools/perf/tests/openat-syscall-tp-fields.c
@@ -44,7 +44,7 @@ int test__syscall_openat_tp_fields(int subtest __maybe_unused)
 		goto out_delete_evlist;
 	}
 
-	perf_evsel__config(evsel, &opts);
+	perf_evsel__config(evsel, &opts, NULL);
 
 	thread_map__set_pid(evlist->threads, 0, getpid());
 
diff --git a/tools/perf/tests/perf-record.c b/tools/perf/tests/perf-record.c
index 1cc78ce..b836ee6a 100644
--- a/tools/perf/tests/perf-record.c
+++ b/tools/perf/tests/perf-record.c
@@ -99,7 +99,7 @@ int test__PERF_RECORD(int subtest __maybe_unused)
 	perf_evsel__set_sample_bit(evsel, CPU);
 	perf_evsel__set_sample_bit(evsel, TID);
 	perf_evsel__set_sample_bit(evsel, TIME);
-	perf_evlist__config(evlist, &opts);
+	perf_evlist__config(evlist, &opts, NULL);
 
 	err = sched__get_first_possible_cpu(evlist->workload.pid, &cpu_mask);
 	if (err < 0) {
diff --git a/tools/perf/tests/switch-tracking.c b/tools/perf/tests/switch-tracking.c
index ebd8016..39a689b 100644
--- a/tools/perf/tests/switch-tracking.c
+++ b/tools/perf/tests/switch-tracking.c
@@ -417,7 +417,7 @@ int test__switch_tracking(int subtest __maybe_unused)
 	perf_evsel__set_sample_bit(tracking_evsel, TIME);
 
 	/* Config events */
-	perf_evlist__config(evlist, &opts);
+	perf_evlist__config(evlist, &opts, NULL);
 
 	/* Check moved event is still at the front */
 	if (cycles_evsel != perf_evlist__first(evlist)) {
diff --git a/tools/perf/tests/tests.h b/tools/perf/tests/tests.h
index 82b2b5e..c57e72c 100644
--- a/tools/perf/tests/tests.h
+++ b/tools/perf/tests/tests.h
@@ -85,6 +85,8 @@ int test__synthesize_stat_config(int subtest);
 int test__synthesize_stat(int subtest);
 int test__synthesize_stat_round(int subtest);
 int test__event_update(int subtest);
+int test__event_times(int subtest);
+int test__backward_ring_buffer(int subtest);
 
 #if defined(__arm__) || defined(__aarch64__)
 #ifdef HAVE_DWARF_UNWIND_SUPPORT
diff --git a/tools/perf/tests/vmlinux-kallsyms.c b/tools/perf/tests/vmlinux-kallsyms.c
index 630b0b4..e63abab 100644
--- a/tools/perf/tests/vmlinux-kallsyms.c
+++ b/tools/perf/tests/vmlinux-kallsyms.c
@@ -54,8 +54,14 @@ int test__vmlinux_matches_kallsyms(int subtest __maybe_unused)
 	 * Step 3:
 	 *
 	 * Load and split /proc/kallsyms into multiple maps, one per module.
+	 * Do not use kcore, as this test was designed before kcore support
+	 * and has parts that only make sense if using the non-kcore code.
+	 * XXX: extend it to stress the kcorre code as well, hint: the list
+	 * of modules extracted from /proc/kcore, in its current form, can't
+	 * be compacted against the list of modules found in the "vmlinux"
+	 * code and with the one got from /proc/modules from the "kallsyms" code.
 	 */
-	if (machine__load_kallsyms(&kallsyms, "/proc/kallsyms", type, NULL) <= 0) {
+	if (__machine__load_kallsyms(&kallsyms, "/proc/kallsyms", type, true, NULL) <= 0) {
 		pr_debug("dso__load_kallsyms ");
 		goto out;
 	}
@@ -157,6 +163,9 @@ next_pair:
 
 					pr_debug("%#" PRIx64 ": diff name v: %s k: %s\n",
 						 mem_start, sym->name, pair->name);
+				} else {
+					pr_debug("%#" PRIx64 ": diff name v: %s k: %s\n",
+						 mem_start, sym->name, first_pair->name);
 				}
 			}
 		} else