From 2ac86de15a33877b301500c211b49990ec76e8e8 Mon Sep 17 00:00:00 2001
From: Tom Cherry <tomcherry@google.com>
Date: Thu, 20 Feb 2020 13:21:51 -0800
Subject: [PATCH] logd: don't coalesce identical log messages in the security
 buffer

This buffer isn't human readable and the parsers aren't set up to
handle the 'chatty' message for identical log messages.  Further, it
is a low volume buffer so there's not much in terms of memory saving
if this were enabled.

Bug: 137093665
Test: security unit tests
Change-Id: I03fce518d3308a6d9240bd29e83ff3237203fe3b
---
 logd/LogBuffer.cpp | 54 +++++++++++++++++++++++++---------------------
 1 file changed, 30 insertions(+), 24 deletions(-)

diff --git a/logd/LogBuffer.cpp b/logd/LogBuffer.cpp
index 834b20b6b..1cf20617f 100644
--- a/logd/LogBuffer.cpp
+++ b/logd/LogBuffer.cpp
@@ -207,31 +207,37 @@ int LogBuffer::log(log_id_t log_id, log_time realtime, uid_t uid, pid_t pid,
     // exact entry with time specified in ms or us precision.
     if ((realtime.tv_nsec % 1000) == 0) ++realtime.tv_nsec;
 
-    LogBufferElement* elem =
-        new LogBufferElement(log_id, realtime, uid, pid, tid, msg, len);
-    if (log_id != LOG_ID_SECURITY) {
-        int prio = ANDROID_LOG_INFO;
-        const char* tag = nullptr;
-        size_t tag_len = 0;
-        if (log_id == LOG_ID_EVENTS || log_id == LOG_ID_STATS) {
-            tag = tagToName(elem->getTag());
-            if (tag) {
-                tag_len = strlen(tag);
-            }
-        } else {
-            prio = *msg;
-            tag = msg + 1;
-            tag_len = strnlen(tag, len - 1);
-        }
-        if (!__android_log_is_loggable_len(prio, tag, tag_len,
-                                           ANDROID_LOG_VERBOSE)) {
-            // Log traffic received to total
-            wrlock();
-            stats.addTotal(elem);
-            unlock();
-            delete elem;
-            return -EACCES;
+    LogBufferElement* elem = new LogBufferElement(log_id, realtime, uid, pid, tid, msg, len);
+
+    // b/137093665: don't coalesce security messages.
+    if (log_id == LOG_ID_SECURITY) {
+        wrlock();
+        log(elem);
+        unlock();
+
+        return len;
+    }
+
+    int prio = ANDROID_LOG_INFO;
+    const char* tag = nullptr;
+    size_t tag_len = 0;
+    if (log_id == LOG_ID_EVENTS || log_id == LOG_ID_STATS) {
+        tag = tagToName(elem->getTag());
+        if (tag) {
+            tag_len = strlen(tag);
         }
+    } else {
+        prio = *msg;
+        tag = msg + 1;
+        tag_len = strnlen(tag, len - 1);
+    }
+    if (!__android_log_is_loggable_len(prio, tag, tag_len, ANDROID_LOG_VERBOSE)) {
+        // Log traffic received to total
+        wrlock();
+        stats.addTotal(elem);
+        unlock();
+        delete elem;
+        return -EACCES;
     }
 
     wrlock();