From c377843258d08d31a2eb7df1a577740e588d2761 Mon Sep 17 00:00:00 2001
From: Mark Salyzyn <salyzyn@google.com>
Date: Thu, 27 Oct 2016 08:13:42 -0700
Subject: [PATCH] libcutils: klog inherit android_get_control_file("/dev/kmsg")

If the file descriptor is in the environment, use it.

Test: compile
Bug: 32450474
Change-Id: Id208b11b727a44dc861a141130a644d7d8009c5f
---
 libcutils/klog.cpp | 7 ++++++-
 1 file changed, 6 insertions(+), 1 deletion(-)

diff --git a/libcutils/klog.cpp b/libcutils/klog.cpp
index 061af1bf4..9d823cfae 100644
--- a/libcutils/klog.cpp
+++ b/libcutils/klog.cpp
@@ -24,6 +24,7 @@
 #include <sys/types.h>
 #include <unistd.h>
 
+#include <cutils/files.h>
 #include <cutils/klog.h>
 
 static int klog_level = KLOG_DEFAULT_LEVEL;
@@ -37,7 +38,11 @@ void klog_set_level(int level) {
 }
 
 static int __open_klog(void) {
-    return TEMP_FAILURE_RETRY(open("/dev/kmsg", O_WRONLY | O_CLOEXEC));
+    static const char kmsg_device[] = "/dev/kmsg";
+
+    int ret = android_get_control_file(kmsg_device);
+    if (ret >= 0) return ret;
+    return TEMP_FAILURE_RETRY(open(kmsg_device, O_WRONLY | O_CLOEXEC));
 }
 
 #define LOG_BUF_MAX 512