1 files changed, 79 insertions, 0 deletions

diff --git a/kernel/trace/ring_buffer.c b/kernel/trace/ring_buffer.c
index c10cf4ba91d6..dc603d9c9414 100644
--- a/kernel/trace/ring_buffer.c
+++ b/kernel/trace/ring_buffer.c
@@ -64,6 +64,10 @@ struct ring_buffer_cpu_meta {
 	unsigned long	commit_buffer;
 	__u32		subbuf_size;
 	__u32		nr_subbufs;
+#ifdef CONFIG_RING_BUFFER_PERSISTENT_INJECT
+	__u32		nr_invalid;
+	__u32		entry_bytes;
+#endif
 	int		buffers[];
 };
 
@@ -2101,6 +2105,21 @@ static void rb_meta_validate_events(struct ring_buffer_per_cpu *cpu_buffer)
 	if (discarded)
 		pr_cont(" (%d pages discarded)", discarded);
 	pr_cont("\n");
+
+#ifdef CONFIG_RING_BUFFER_PERSISTENT_INJECT
+	if (meta->nr_invalid)
+		pr_warn("Ring buffer testing [%d] invalid pages: %s (%d/%d)\n",
+			cpu_buffer->cpu,
+			(discarded == meta->nr_invalid) ? "PASSED" : "FAILED",
+			discarded, meta->nr_invalid);
+	if (meta->entry_bytes)
+		pr_warn("Ring buffer testing [%d] entry_bytes: %s (%ld/%ld)\n",
+			cpu_buffer->cpu,
+			(entry_bytes == meta->entry_bytes) ? "PASSED" : "FAILED",
+			(long)entry_bytes, (long)meta->entry_bytes);
+	meta->nr_invalid = 0;
+	meta->entry_bytes = 0;
+#endif
 	return;
 
  invalid:
@@ -2581,12 +2600,72 @@ static void rb_free_cpu_buffer(struct ring_buffer_per_cpu *cpu_buffer)
 	kfree(cpu_buffer);
 }
 
+#ifdef CONFIG_RING_BUFFER_PERSISTENT_INJECT
+static void rb_test_inject_invalid_pages(struct trace_buffer *buffer)
+{
+	struct ring_buffer_per_cpu *cpu_buffer;
+	struct ring_buffer_cpu_meta *meta;
+	struct buffer_data_page *dpage;
+	unsigned long entry_bytes = 0;
+	unsigned long ptr;
+	int subbuf_size;
+	int invalid = 0;
+	int cpu;
+	int i;
+
+	if (!(buffer->flags & RB_FL_TESTING))
+		return;
+
+	guard(preempt)();
+	cpu = smp_processor_id();
+
+	cpu_buffer = buffer->buffers[cpu];
+	if (!cpu_buffer)
+		return;
+	meta = cpu_buffer->ring_meta;
+	if (!meta)
+		return;
+
+	ptr = (unsigned long)rb_subbufs_from_meta(meta);
+	subbuf_size = meta->subbuf_size;
+
+	for (i = 0; i < meta->nr_subbufs; i++) {
+		unsigned long idx = meta->buffers[i];
+
+		dpage = (void *)(ptr + idx * subbuf_size);
+		/* Skip unused pages */
+		if (!local_read(&dpage->commit))
+			continue;
+
+		/*
+		 * Invalidate even pages or multiples of 5. This will cause 3
+		 * contiguous invalidated(empty) pages.
+		 */
+		if (!(i & 0x1) || !(i % 5)) {
+			local_add(subbuf_size + 1, &dpage->commit);
+			invalid++;
+		} else {
+			/* Count total commit bytes. */
+			entry_bytes += local_read(&dpage->commit) & ~RB_MISSED_MASK;
+		}
+	}
+
+	pr_info("Inject invalidated %d pages on CPU%d, total size: %ld\n",
+		invalid, cpu, (long)entry_bytes);
+	meta->nr_invalid = invalid;
+	meta->entry_bytes = entry_bytes;
+}
+#else /* !CONFIG_RING_BUFFER_PERSISTENT_INJECT */
+#define rb_test_inject_invalid_pages(buffer)	do { } while (0)
+#endif
+
 /* Stop recording on a persistent buffer and flush cache if needed. */
 static int rb_flush_buffer_cb(struct notifier_block *nb, unsigned long event, void *data)
 {
 	struct trace_buffer *buffer = container_of(nb, struct trace_buffer, flush_nb);
 
 	ring_buffer_record_off(buffer);
+	rb_test_inject_invalid_pages(buffer);
 	arch_ring_buffer_flush_range(buffer->range_addr_start, buffer->range_addr_end);
 	return NOTIFY_DONE;
 }