commit 8b11c4cec21dc8eedd153866ce738614cfae57e6
author Geremy Condra <gcondra@google.com> Thu Jun 07 17:45:06 2012 -0700
committer Geremy Condra <gcondra@google.com> Fri Jun 08 12:14:48 2012 -0700
tree ee313cc132aeda193792e290d1e4749f8f2e1712
parent 158ad015c2eb8f0a7f0e91db706ca363e634f407

Adding event logging to libc.

I've basically just copied the relevant bits out of liblog and
EventLog.cpp. While this will let us do the uid logging we want
to address the concerns in 245c07027f78565858dd489eb0d94c3d48743e9d
it doesn't give us much else.

Change-Id: Icac6ff20bc0a3ade5927f6f76fedffe1ae6f8522

libc/bionic/logd_write.c

diff --git a/libc/bionic/logd_write.c b/libc/bionic/logd_write.c
index 2bc39fa..ac71689 100644
--- a/libc/bionic/logd_write.c
+++ b/libc/bionic/logd_write.c
@@ -64,6 +64,7 @@
     LOG_ID_NONE = 0,
     LOG_ID_MAIN,
     LOG_ID_RADIO,
+    LOG_ID_EVENTS,
     LOG_ID_MAX
 } log_id_t;
 
@@ -84,7 +85,8 @@
 static log_channel_t log_channels[LOG_ID_MAX] = {
     { __write_to_log_null, -1, NULL },
     { __write_to_log_init, -1, "/dev/"LOGGER_LOG_MAIN },
-    { __write_to_log_init, -1, "/dev/"LOGGER_LOG_RADIO }
+    { __write_to_log_init, -1, "/dev/"LOGGER_LOG_RADIO },
+    { __write_to_log_init, -1, "/dev/"LOGGER_LOG_EVENTS }
 };
 
 /* Important: see technical note at start of source file */
@@ -207,3 +209,41 @@
 
     return -1;
 }
+
+/*
+ * Event logging.
+ */
+
+// must be kept in sync with frameworks/base/core/java/android/util/EventLog.java
+typedef enum {
+    EVENT_TYPE_INT      = 0,
+    EVENT_TYPE_LONG     = 1,
+    EVENT_TYPE_STRING   = 2,
+    EVENT_TYPE_LIST     = 3,
+} AndroidEventLogType;
+
+static int __libc_android_log_btwrite(int32_t tag, char type, const void *payload, size_t len)
+{
+    struct iovec vec[3];
+
+    vec[0].iov_base = &tag;
+    vec[0].iov_len = sizeof(tag);
+    vec[1].iov_base = &type;
+    vec[1].iov_len = sizeof(type);
+    vec[2].iov_base = (void*)payload;
+    vec[2].iov_len = len;
+
+    return log_channels[LOG_ID_EVENTS].logger(LOG_ID_EVENTS, vec);
+}
+
+__LIBC_HIDDEN__
+void __libc_android_log_event_int(int32_t tag, int value)
+{
+    __libc_android_log_btwrite(tag, EVENT_TYPE_INT, &value, sizeof(value));
+}
+
+__LIBC_HIDDEN__
+void __libc_android_log_event_uid(int32_t tag)
+{
+    __libc_android_log_event_int(tag, getuid());
+}

libc/private/logd.h

diff --git a/libc/private/logd.h b/libc/private/logd.h
index 4a9b62e..37d4104 100644
--- a/libc/private/logd.h
+++ b/libc/private/logd.h
@@ -48,4 +48,7 @@
 int __libc_android_log_print(int prio, const char *tag, const char *fmt, ...);
 int __libc_android_log_vprint(int prio, const char *tag, const char *fmt, va_list ap);
 
+void __libc_android_log_event_int(int32_t tag, int value);
+void __libc_android_log_event_uid(int32_t tag);
+
 #endif /* _ANDROID_BIONIC_LOGD_H */