llkd: Disable in userdebug builds by default

While llkd helps in discovering issues in apps which leave zombies, it
creates issues for dogfooders when apps are killed. Disable it by
default.

Bug: 202411543
Test: boot and check llkd not running
Test: `setprop ro.llk.enable true` enables llkd
Signed-off-by: Suren Baghdasaryan <[email protected]>
Change-Id: If93bf9e981eaa3921a9da5f3160db26c4fe17e66

Author: surenbaghdasaryan

llkd/libllkd.cpp

@@ -1283,8 +1283,7 @@ bool llkInit(const char* threadname) {
     llkEnableSysrqT &= !llkLowRam;
     if (debuggable) {
         llkEnableSysrqT |= llkCheckEng(LLK_ENABLE_SYSRQ_T_PROPERTY);
-        if (!LLK_ENABLE_DEFAULT) {  // NB: default is currently true ...
-            llkEnable |= llkCheckEng(LLK_ENABLE_PROPERTY);
+        if (!LLK_ENABLE_DEFAULT) {
             khtEnable |= llkCheckEng(KHT_ENABLE_PROPERTY);
         }
     }

llkd/llkd-debuggable.rc

@@ -1,5 +1,5 @@
 on property:ro.debuggable=1
-    setprop llk.enable ${ro.llk.enable:-1}
+    setprop llk.enable ${ro.llk.enable:-0}
     setprop khungtask.enable ${ro.khungtask.enable:-1}
 
 on property:ro.llk.enable=eng

llkd/tests/llkd_test.cpp

@@ -69,13 +69,9 @@ void execute(const char* command) {
 seconds llkdSleepPeriod(char state) {
     auto default_eng = android::base::GetProperty(LLK_ENABLE_PROPERTY, "eng") == "eng";
     auto default_enable = LLK_ENABLE_DEFAULT;
-    if (!LLK_ENABLE_DEFAULT && default_eng &&
-        android::base::GetBoolProperty("ro.debuggable", false)) {
-        default_enable = true;
-    }
     default_enable = android::base::GetBoolProperty(LLK_ENABLE_PROPERTY, default_enable);
     if (default_eng) {
-        GTEST_LOG_INFO << LLK_ENABLE_PROPERTY " defaults to \"eng\" thus "
+        GTEST_LOG_INFO << LLK_ENABLE_PROPERTY " defaults to "
                        << (default_enable ? "true" : "false") << "\n";
     }
     // Hail Mary hope is unconfigured.
@@ -108,10 +104,6 @@ seconds llkdSleepPeriod(char state) {
         rest();
     }
     default_enable = LLK_ENABLE_DEFAULT;
-    if (!LLK_ENABLE_DEFAULT && (android::base::GetProperty(LLK_ENABLE_PROPERTY, "eng") == "eng") &&
-        android::base::GetBoolProperty("ro.debuggable", false)) {
-        default_enable = true;
-    }
     default_enable = android::base::GetBoolProperty(LLK_ENABLE_PROPERTY, default_enable);
     if (default_enable) {
         execute("start llkd-1");