perf/core: Implement the 'perf_uprobe' PMU

This patch adds perf_uprobe support with similar pattern as previous
patch (for kprobe).

Two functions, create_local_trace_uprobe() and
destroy_local_trace_uprobe(), are created so a uprobe can be created
and attached to the file descriptor created by perf_event_open().

Signed-off-by: Song Liu <songliubraving@fb.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Yonghong Song <yhs@fb.com>
Reviewed-by: Josef Bacik <jbacik@fb.com>
Cc: <daniel@iogearbox.net>
Cc: <davem@davemloft.net>
Cc: <kernel-team@fb.com>
Cc: <rostedt@goodmis.org>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/20171206224518.3598254-7-songliubraving@fb.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>

1 files changed, 47 insertions, 1 deletions

diff --git a/kernel/events/core.c b/kernel/events/core.c
index 333735531968..5a54630db86b 100644
--- a/kernel/events/core.c
+++ b/kernel/events/core.c
@@ -7992,7 +7992,7 @@ static struct pmu perf_tracepoint = {
 	.read		= perf_swevent_read,
 };
 
-#ifdef CONFIG_KPROBE_EVENTS
+#if defined(CONFIG_KPROBE_EVENTS) || defined(CONFIG_UPROBE_EVENTS)
 /*
  * Flags in config, used by dynamic PMU kprobe and uprobe
  * The flags should match following PMU_FORMAT_ATTR().
@@ -8020,7 +8020,9 @@ static const struct attribute_group *probe_attr_groups[] = {
 	&probe_format_group,
 	NULL,
 };
+#endif
 
+#ifdef CONFIG_KPROBE_EVENTS
 static int perf_kprobe_event_init(struct perf_event *event);
 static struct pmu perf_kprobe = {
 	.task_ctx_nr	= perf_sw_context,
@@ -8057,12 +8059,52 @@ static int perf_kprobe_event_init(struct perf_event *event)
 }
 #endif /* CONFIG_KPROBE_EVENTS */
 
+#ifdef CONFIG_UPROBE_EVENTS
+static int perf_uprobe_event_init(struct perf_event *event);
+static struct pmu perf_uprobe = {
+	.task_ctx_nr	= perf_sw_context,
+	.event_init	= perf_uprobe_event_init,
+	.add		= perf_trace_add,
+	.del		= perf_trace_del,
+	.start		= perf_swevent_start,
+	.stop		= perf_swevent_stop,
+	.read		= perf_swevent_read,
+	.attr_groups	= probe_attr_groups,
+};
+
+static int perf_uprobe_event_init(struct perf_event *event)
+{
+	int err;
+	bool is_retprobe;
+
+	if (event->attr.type != perf_uprobe.type)
+		return -ENOENT;
+	/*
+	 * no branch sampling for probe events
+	 */
+	if (has_branch_stack(event))
+		return -EOPNOTSUPP;
+
+	is_retprobe = event->attr.config & PERF_PROBE_CONFIG_IS_RETPROBE;
+	err = perf_uprobe_init(event, is_retprobe);
+	if (err)
+		return err;
+
+	event->destroy = perf_uprobe_destroy;
+
+	return 0;
+}
+#endif /* CONFIG_UPROBE_EVENTS */
+
 static inline void perf_tp_register(void)
 {
 	perf_pmu_register(&perf_tracepoint, "tracepoint", PERF_TYPE_TRACEPOINT);
 #ifdef CONFIG_KPROBE_EVENTS
 	perf_pmu_register(&perf_kprobe, "kprobe", -1);
 #endif
+#ifdef CONFIG_UPROBE_EVENTS
+	perf_pmu_register(&perf_uprobe, "uprobe", -1);
+#endif
 }
 
 static void perf_event_free_filter(struct perf_event *event)
@@ -8151,6 +8193,10 @@ static inline bool perf_event_is_tracing(struct perf_event *event)
 	if (event->pmu == &perf_kprobe)
 		return true;
 #endif
+#ifdef CONFIG_UPROBE_EVENTS
+	if (event->pmu == &perf_uprobe)
+		return true;
+#endif
 	return false;
 }