liblog: reject empty logging messages
A regression after "liblog: Instrument logging of logd write drops"
where an empty payload would result in an insufficient iovec to
report the write drop.
Change-Id: Iffabcfbb0680898d7a42004700e638e9d940ff5f
diff --git a/liblog/logd_write.c b/liblog/logd_write.c
index a865093..8f8cc3f 100644
--- a/liblog/logd_write.c
+++ b/liblog/logd_write.c
@@ -178,6 +178,10 @@
static pid_t last_pid = (pid_t) -1;
static atomic_int_fast32_t dropped;
+ if (!nr) {
+ return -EINVAL;
+ }
+
if (last_uid == AID_ROOT) { /* have we called to get the UID yet? */
last_uid = getuid();
}