From 076ba81ce997e408c662be438ac37eb532b72eda Mon Sep 17 00:00:00 2001 From: Mark Salyzyn Date: Thu, 29 May 2014 17:53:41 -0700 Subject: [PATCH] liblog: cache getuid() syscall BUG: 15315766 Change-Id: I8f889a1c6ede74f2621f1b8ea5fda666c4b9cba2 --- liblog/logd_write.c | 17 ++++++++++------- 1 file changed, 10 insertions(+), 7 deletions(-) diff --git a/liblog/logd_write.c b/liblog/logd_write.c index 121d84dff..f10eb8e0b 100644 --- a/liblog/logd_write.c +++ b/liblog/logd_write.c @@ -159,10 +159,14 @@ static int __write_to_log_kernel(log_id_t log_id, struct iovec *vec, size_t nr) struct timespec ts; log_time realtime_ts; size_t i, payload_size; + static uid_t last_uid = AID_ROOT; /* logd *always* starts up as AID_ROOT */ - if (getuid() == AID_LOGD) { + if (last_uid == AID_ROOT) { /* have we called to get the UID yet? */ + last_uid = getuid(); + } + if (last_uid == AID_LOGD) { /* logd, after initialization and priv drop */ /* - * ignore log messages we send to ourself. + * ignore log messages we send to ourself (logd). * Such log messages are often generated by libraries we depend on * which use standard Android logging. */ @@ -193,6 +197,10 @@ static int __write_to_log_kernel(log_id_t log_id, struct iovec *vec, size_t nr) * }; */ + clock_gettime(CLOCK_REALTIME, &ts); + realtime_ts.tv_sec = ts.tv_sec; + realtime_ts.tv_nsec = ts.tv_nsec; + log_id_buf = log_id; tid = gettid(); @@ -200,11 +208,6 @@ static int __write_to_log_kernel(log_id_t log_id, struct iovec *vec, size_t nr) newVec[0].iov_len = sizeof_log_id_t; newVec[1].iov_base = (unsigned char *) &tid; newVec[1].iov_len = sizeof(tid); - - clock_gettime(CLOCK_REALTIME, &ts); - realtime_ts.tv_sec = ts.tv_sec; - realtime_ts.tv_nsec = ts.tv_nsec; - newVec[2].iov_base = (unsigned char *) &realtime_ts; newVec[2].iov_len = sizeof(log_time);