tools/perf/util/auxtrace.c

Source file repositories/reference/linux-study-clean/tools/perf/util/auxtrace.c

File Facts

System
Linux kernel
Corpus path
tools/perf/util/auxtrace.c
Extension
.c
Size
68505 bytes
Lines
2963
Domain
Support Tooling And Documentation
Bucket
tools
Inferred role
Support Tooling And Documentation: implementation source
Status
source implementation candidate

Why This File Exists

Repository support layer: documentation, build tooling, samples, user-space helper tools, generated initramfs support, licenses, and validation utilities.

Dependency Surface

Detected Declarations

Annotated Snippet

struct queue_data {
	bool samples;
	bool events;
};

static int auxtrace_queue_data_cb(struct perf_session *session,
				  union perf_event *event, u64 offset,
				  void *data)
{
	struct queue_data *qd = data;
	struct perf_sample sample;
	int err;

	if (qd->events && event->header.type == PERF_RECORD_AUXTRACE) {
		if (event->header.size < sizeof(struct perf_record_auxtrace))
			return -EINVAL;
		offset += event->header.size;
		return session->auxtrace->queue_data(session, NULL, event,
						     offset);
	}

	if (!qd->samples || event->header.type != PERF_RECORD_SAMPLE)
		return 0;

	perf_sample__init(&sample, /*all=*/false);
	err = evlist__parse_sample(session->evlist, event, &sample);
	if (err)
		goto out;

	if (sample.aux_sample.size) {
		offset += sample.aux_sample.data - (void *)event;

		err = session->auxtrace->queue_data(session, &sample, NULL, offset);
	}
out:
	perf_sample__exit(&sample);
	return err;
}

int auxtrace_queue_data(struct perf_session *session, bool samples, bool events)
{
	struct queue_data qd = {
		.samples = samples,
		.events = events,
	};

	if (auxtrace__dont_decode(session))
		return 0;

	if (perf_data__is_pipe(session->data))
		return 0;

	if (!session->auxtrace || !session->auxtrace->queue_data)
		return -EINVAL;

	return perf_session__peek_events(session, session->header.data_offset,
					 session->header.data_size,
					 auxtrace_queue_data_cb, &qd);
}

void *auxtrace_buffer__get_data_rw(struct auxtrace_buffer *buffer, int fd, bool rw)
{
	int prot = rw ? PROT_READ | PROT_WRITE : PROT_READ;
	size_t adj = buffer->data_offset & (page_size - 1);
	size_t size = buffer->size + adj;
	off_t file_offset = buffer->data_offset - adj;
	void *addr;

	if (buffer->data)
		return buffer->data;

	addr = mmap(NULL, size, prot, MAP_SHARED, fd, file_offset);
	if (addr == MAP_FAILED)
		return NULL;

	buffer->mmap_addr = addr;
	buffer->mmap_size = size;

	buffer->data = addr + adj;

	return buffer->data;
}

void auxtrace_buffer__put_data(struct auxtrace_buffer *buffer)
{
	if (!buffer->data || !buffer->mmap_addr)
		return;
	munmap(buffer->mmap_addr, buffer->mmap_size);
	buffer->mmap_addr = NULL;
	buffer->mmap_size = 0;

Annotation

Implementation Notes