commit 90a74600d772ee578aaf5c63005e2d80b0d223c9
author Saurabh Shah <saurshah@quicinc.com> Tue Aug 01 13:54:21 2017 -0700
committer Marissa Wall <marissaw@google.com> Mon Sep 25 15:51:46 2017 -0700
tree f8ac4b2019959b65429abfdc2ad3c52b3574d5c7
parent 22a10f6766cd3ae07217b9a93c44381f52aa7018

sync: store the num_fences from first SYNC_IOC_FILE_INFO

Fixes a bug with the signal time of devices using the
modern sync file interface. The bug only affects kernels running
an Android kernel 4.9 and later.

b/63395253

Test: tests/sync_test.cpp

Change-Id: I6fb00bcb8e16a3268c357153edd8e35a44546caa

libsync/sync.c

diff --git a/libsync/sync.c b/libsync/sync.c
index e657658..6b187fa 100644
--- a/libsync/sync.c
+++ b/libsync/sync.c
@@ -217,6 +217,8 @@
                   local_info.num_fences * sizeof(struct sync_fence_info));
     if (!info)
         return NULL;
+
+    info->num_fences = local_info.num_fences;
     info->sync_fence_info = (__u64)(uintptr_t)(info + 1);
 
     err = ioctl(fd, SYNC_IOC_FILE_INFO, info);