1 files changed, 106 insertions, 4 deletions

diff --git a/tools/perf/builtin-test.c b/tools/perf/builtin-test.c
index 035b9fa063a9..1c984342a579 100644
--- a/tools/perf/builtin-test.c
+++ b/tools/perf/builtin-test.c
@@ -119,10 +119,16 @@ static int test__vmlinux_matches_kallsyms(void)
 	 * end addresses too.
 	 */
 	for (nd = rb_first(&vmlinux_map->dso->symbols[type]); nd; nd = rb_next(nd)) {
-		struct symbol *pair;
+		struct symbol *pair, *first_pair;
+		bool backwards = true;
 
 		sym  = rb_entry(nd, struct symbol, rb_node);
-		pair = machine__find_kernel_symbol(&kallsyms, type, sym->start, NULL, NULL);
+
+		if (sym->start == sym->end)
+			continue;
+
+		first_pair = machine__find_kernel_symbol(&kallsyms, type, sym->start, NULL, NULL);
+		pair = first_pair;
 
 		if (pair && pair->start == sym->start) {
 next_pair:
@@ -143,8 +149,10 @@ next_pair:
 				pr_debug("%#Lx: diff end addr for %s v: %#Lx k: %#Lx\n",
 					 sym->start, sym->name, sym->end, pair->end);
 			} else {
-				struct rb_node *nnd = rb_prev(&pair->rb_node);
-
+				struct rb_node *nnd;
+detour:
+				nnd = backwards ? rb_prev(&pair->rb_node) :
+						  rb_next(&pair->rb_node);
 				if (nnd) {
 					struct symbol *next = rb_entry(nnd, struct symbol, rb_node);
 
@@ -153,6 +161,13 @@ next_pair:
 						goto next_pair;
 					}
 				}
+
+				if (backwards) {
+					backwards = false;
+					pair = first_pair;
+					goto detour;
+				}
+
 				pr_debug("%#Lx: diff name v: %s k: %s\n",
 					 sym->start, sym->name, pair->name);
 			}
@@ -219,6 +234,89 @@ out:
 	return err;
 }
 
+#include "util/evsel.h"
+#include <sys/types.h>
+
+static int trace_event__id(const char *event_name)
+{
+	char *filename;
+	int err = -1, fd;
+
+	if (asprintf(&filename,
+		     "/sys/kernel/debug/tracing/events/syscalls/%s/id",
+		     event_name) < 0)
+		return -1;
+
+	fd = open(filename, O_RDONLY);
+	if (fd >= 0) {
+		char id[16];
+		if (read(fd, id, sizeof(id)) > 0)
+			err = atoi(id);
+		close(fd);
+	}
+
+	free(filename);
+	return err;
+}
+
+static int test__open_syscall_event(void)
+{
+	int err = -1, fd;
+	struct thread_map *threads;
+	struct perf_evsel *evsel;
+	unsigned int nr_open_calls = 111, i;
+	int id = trace_event__id("sys_enter_open");
+
+	if (id < 0) {
+		pr_debug("is debugfs mounted on /sys/kernel/debug?\n");
+		return -1;
+	}
+
+	threads = thread_map__new(-1, getpid());
+	if (threads == NULL) {
+		pr_debug("thread_map__new\n");
+		return -1;
+	}
+
+	evsel = perf_evsel__new(PERF_TYPE_TRACEPOINT, id, 0);
+	if (evsel == NULL) {
+		pr_debug("perf_evsel__new\n");
+		goto out_thread_map_delete;
+	}
+
+	if (perf_evsel__open_per_thread(evsel, threads) < 0) {
+		pr_debug("failed to open counter: %s, "
+			 "tweak /proc/sys/kernel/perf_event_paranoid?\n",
+			 strerror(errno));
+		goto out_evsel_delete;
+	}
+
+	for (i = 0; i < nr_open_calls; ++i) {
+		fd = open("/etc/passwd", O_RDONLY);
+		close(fd);
+	}
+
+	if (perf_evsel__read_on_cpu(evsel, 0, 0) < 0) {
+		pr_debug("perf_evsel__open_read_on_cpu\n");
+		goto out_close_fd;
+	}
+
+	if (evsel->counts->cpu[0].val != nr_open_calls) {
+		pr_debug("perf_evsel__read_on_cpu: expected to intercept %d calls, got %Ld\n",
+			 nr_open_calls, evsel->counts->cpu[0].val);
+		goto out_close_fd;
+	}
+	
+	err = 0;
+out_close_fd:
+	perf_evsel__close_fd(evsel, 1, threads->nr);
+out_evsel_delete:
+	perf_evsel__delete(evsel);
+out_thread_map_delete:
+	thread_map__delete(threads);
+	return err;
+}
+
 static struct test {
 	const char *desc;
 	int (*func)(void);
@@ -228,6 +326,10 @@ static struct test {
 		.func = test__vmlinux_matches_kallsyms,
 	},
 	{
+		.desc = "detect open syscall event",
+		.func = test__open_syscall_event,
+	},
+	{
 		.func = NULL,
 	},
 };