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.
(cherrypicked from commit 4d32a486fe62ef2c1440167604654a2f4e023fbd)
Bug: 21242418
Change-Id: I0c88d80feca6899fcdbc8c9f2f99448ee0a3422d
diff --git a/libcutils/klog.c b/libcutils/klog.c
index f574f08..710dc66 100644
--- a/libcutils/klog.c
+++ b/libcutils/klog.c
@@ -40,6 +40,11 @@
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);