[PATCH 06/12] perf auxtrace: Allow buffers to be mapped read / write

[Adrian Hunter <adrian.hunter@intel.com>]

To support in-place update, allow buffers to be mapped read / write.

Signed-off-by: Adrian Hunter <adrian.hunter@intel.com>
---
 tools/perf/util/auxtrace.c | 5 +++--
 tools/perf/util/auxtrace.h | 6 +++++-
 2 files changed, 8 insertions(+), 3 deletions(-)

diff --git a/tools/perf/util/auxtrace.c b/tools/perf/util/auxtrace.c
index 48b88e2bca1e..ade655d58780 100644
--- a/tools/perf/util/auxtrace.c
+++ b/tools/perf/util/auxtrace.c
@@ -1120,8 +1120,9 @@ int auxtrace_queue_data(struct perf_session *session, bool samples, bool events)
 					 auxtrace_queue_data_cb, &qd);
 }
 
-void *auxtrace_buffer__get_data(struct auxtrace_buffer *buffer, int fd)
+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;
@@ -1130,7 +1131,7 @@ void *auxtrace_buffer__get_data(struct auxtrace_buffer *buffer, int fd)
 	if (buffer->data)
 		return buffer->data;
 
-	addr = mmap(NULL, size, PROT_READ, MAP_SHARED, fd, file_offset);
+	addr = mmap(NULL, size, prot, MAP_SHARED, fd, file_offset);
 	if (addr == MAP_FAILED)
 		return NULL;
 
diff --git a/tools/perf/util/auxtrace.h b/tools/perf/util/auxtrace.h
index 9ac2ac1bd793..472c0973b1f1 100644
--- a/tools/perf/util/auxtrace.h
+++ b/tools/perf/util/auxtrace.h
@@ -533,7 +533,11 @@ int auxtrace_queue_data(struct perf_session *session, bool samples,
 			bool events);
 struct auxtrace_buffer *auxtrace_buffer__next(struct auxtrace_queue *queue,
 					      struct auxtrace_buffer *buffer);
-void *auxtrace_buffer__get_data(struct auxtrace_buffer *buffer, int fd);
+void *auxtrace_buffer__get_data_rw(struct auxtrace_buffer *buffer, int fd, bool rw);
+static inline void *auxtrace_buffer__get_data(struct auxtrace_buffer *buffer, int fd)
+{
+	return auxtrace_buffer__get_data_rw(buffer, fd, false);
+}
 void auxtrace_buffer__put_data(struct auxtrace_buffer *buffer);
 void auxtrace_buffer__drop_data(struct auxtrace_buffer *buffer);
 void auxtrace_buffer__free(struct auxtrace_buffer *buffer);
-- 
2.17.1