Document bionic loader logging properties
Bug: http://b/29458203
Test: spellchecker in vim
Change-Id: I81e60a09fa256110d7ab9b530e7821ae66e8f020
diff --git a/android-changes-for-ndk-developers.md b/android-changes-for-ndk-developers.md
index 5b0fe38..ec48870 100644
--- a/android-changes-for-ndk-developers.md
+++ b/android-changes-for-ndk-developers.md
@@ -321,3 +321,22 @@
*Resolution*: don't use tools that produce invalid/malformed
ELF files. Note that using them puts application under high risk of
being incompatible with future versions of Android.
+
+## Enable logging of dlopen/dlsym and library loading errors for apps (Available in Android O)
+
+Starting with Android O it is possible to enable logging of all dlsym/dlopen calls
+for debuggable apps. Here is short instruction on how to do that:
+```
+adb shell setprop debug.ld.app.com.example.myapp dlsym,dlopen,dlerror
+adb logcat
+```
+
+Any subset of (dlsym,dlopen,dlerror) can be used.
+
+On userdebug and eng builds it is possible to enable tracing for the whole system
+by using debug.ld.all system property instead of app-specific one:
+```
+adb shell setprop debug.ld.all dlerror,dlopen
+```
+
+enables logging of all errors and dlopen calls