From 2a4d05a4e38b84cf287bb2d2266c07b6f10c9dee Mon Sep 17 00:00:00 2001
From: Nick Kralevich <nnk@google.com>
Date: Tue, 1 Jul 2014 10:57:16 -0700
Subject: [PATCH] implement LOG_EVENT_STRING

Implement LOG_EVENT_STRING, so that native code can create new
event log entries. This is needed to support logging SELinux denials
to the event log.

Change-Id: I6a269a832bc2f5e5da6c9dbd169ed2f901b49166
---
 include/log/log.h        |  2 +-
 include/log/logd.h       |  1 +
 liblog/logd_write.c      | 22 ++++++++++++++++++++++
 liblog/logd_write_kern.c | 22 ++++++++++++++++++++++
 4 files changed, 46 insertions(+), 1 deletion(-)

diff --git a/include/log/log.h b/include/log/log.h
index 5b76c1a4b..ace12d631 100644
--- a/include/log/log.h
+++ b/include/log/log.h
@@ -491,7 +491,7 @@ typedef enum {
 #endif
 #ifndef LOG_EVENT_STRING
 #define LOG_EVENT_STRING(_tag, _value)                                      \
-    ((void) 0)  /* not implemented -- must combine len with string */
+        (void) __android_log_bswrite(_tag, _value);
 #endif
 /* TODO: something for LIST */
 
diff --git a/include/log/logd.h b/include/log/logd.h
index 379c37334..2e6f22005 100644
--- a/include/log/logd.h
+++ b/include/log/logd.h
@@ -41,6 +41,7 @@ extern "C" {
 int __android_log_bwrite(int32_t tag, const void *payload, size_t len);
 int __android_log_btwrite(int32_t tag, char type, const void *payload,
     size_t len);
+int __android_log_bswrite(int32_t tag, const char *payload);
 
 #ifdef __cplusplus
 }
diff --git a/liblog/logd_write.c b/liblog/logd_write.c
index f10eb8e0b..1da55ab98 100644
--- a/liblog/logd_write.c
+++ b/liblog/logd_write.c
@@ -473,3 +473,25 @@ int __android_log_btwrite(int32_t tag, char type, const void *payload,
 
     return write_to_log(LOG_ID_EVENTS, vec, 3);
 }
+
+/*
+ * Like __android_log_bwrite, but used for writing strings to the
+ * event log.
+ */
+int __android_log_bswrite(int32_t tag, const char *payload)
+{
+    struct iovec vec[4];
+    char type = EVENT_TYPE_STRING;
+    uint32_t len = strlen(payload);
+
+    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 = &len;
+    vec[2].iov_len = sizeof(len);
+    vec[3].iov_base = (void*)payload;
+    vec[3].iov_len = len;
+
+    return write_to_log(LOG_ID_EVENTS, vec, 4);
+}
diff --git a/liblog/logd_write_kern.c b/liblog/logd_write_kern.c
index 1d107481d..1ed5ecfbf 100644
--- a/liblog/logd_write_kern.c
+++ b/liblog/logd_write_kern.c
@@ -317,3 +317,25 @@ int __android_log_btwrite(int32_t tag, char type, const void *payload,
 
     return write_to_log(LOG_ID_EVENTS, vec, 3);
 }
+
+/*
+ * Like __android_log_bwrite, but used for writing strings to the
+ * event log.
+ */
+int __android_log_bswrite(int32_t tag, const char *payload)
+{
+    struct iovec vec[4];
+    char type = EVENT_TYPE_STRING;
+    uint32_t len = strlen(payload);
+
+    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 = &len;
+    vec[2].iov_len = sizeof(len);
+    vec[3].iov_base = (void*)payload;
+    vec[3].iov_len = len;
+
+    return write_to_log(LOG_ID_EVENTS, vec, 4);
+}