From 4d32a486fe62ef2c1440167604654a2f4e023fbd Mon Sep 17 00:00:00 2001
From: Nick Kralevich <nnk@google.com>
Date: Mon, 18 May 2015 18:41:23 -0700
Subject: [PATCH] klog: don't unconditionally call mknod()

If /dev/kmsg already exists, it's unnecessary for klog_init()
to create it's own copy. This avoids needing to grant the mknod
permission to everyone who uses kmsg. Typically the only time
/dev/kmsg doesn't exist is before ueventd starts.

Bug: 21242418
Change-Id: I0c88d80feca6899fcdbc8c9f2f99448ee0a3422d
---
 libcutils/klog.c | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/libcutils/klog.c b/libcutils/klog.c
index f574f08cd..710dc6669 100644
--- a/libcutils/klog.c
+++ b/libcutils/klog.c
@@ -40,6 +40,11 @@ void klog_set_level(int level) {
 void klog_init(void) {
     if (klog_fd >= 0) return; /* Already initialized */
 
+    klog_fd = open("/dev/kmsg", O_WRONLY | O_CLOEXEC);
+    if (klog_fd >= 0) {
+        return;
+    }
+
     static const char* name = "/dev/__kmsg__";
     if (mknod(name, S_IFCHR | 0600, (1 << 8) | 11) == 0) {
         klog_fd = open(name, O_WRONLY | O_CLOEXEC);