Merge "Prevent Infinite Recursion in Telecom Sessions"
diff --git a/telecomm/java/android/telecom/Logging/Session.java b/telecomm/java/android/telecom/Logging/Session.java
index c45bd6b..4a8bae7 100644
--- a/telecomm/java/android/telecom/Logging/Session.java
+++ b/telecomm/java/android/telecom/Logging/Session.java
@@ -33,6 +33,8 @@
*/
public class Session {
+ public static final String LOG_TAG = "Session";
+
public static final String START_SESSION = "START_SESSION";
public static final String START_EXTERNAL_SESSION = "START_EXTERNAL_SESSION";
public static final String CREATE_SUBSESSION = "CREATE_SUBSESSION";
@@ -45,6 +47,9 @@
public static final String EXTERNAL_INDICATOR = "E-";
public static final String TRUNCATE_STRING = "...";
+ // Prevent infinite recursion by setting a reasonable limit.
+ private static final int SESSION_RECURSION_LIMIT = 25;
+
/**
* Initial value of mExecutionEndTimeMs and the final value of {@link #getLocalExecutionTime()}
* if the Session is canceled.
@@ -226,6 +231,15 @@
// Builds full session id recursively
private String getFullSessionId() {
+ return getFullSessionId(0);
+ }
+
+ // keep track of calls and bail if we hit the recursion limit
+ private String getFullSessionId(int parentCount) {
+ if (parentCount >= SESSION_RECURSION_LIMIT) {
+ Log.w(LOG_TAG, "getFullSessionId: Hit recursion limit!");
+ return TRUNCATE_STRING + mSessionId;
+ }
// Cache mParentSession locally to prevent a concurrency problem where
// Log.endParentSessions() is called while a logging statement is running (Log.i, for
// example) and setting mParentSession to null in a different thread after the null check
@@ -235,42 +249,57 @@
return mSessionId;
} else {
if (Log.VERBOSE) {
- return parentSession.getFullSessionId() +
+ return parentSession.getFullSessionId(parentCount + 1)
// Append "_X" to subsession to show subsession designation.
- SESSION_SEPARATION_CHAR_CHILD + mSessionId;
+ + SESSION_SEPARATION_CHAR_CHILD + mSessionId;
} else {
// Only worry about the base ID at the top of the tree.
- return parentSession.getFullSessionId();
+ return parentSession.getFullSessionId(parentCount + 1);
}
}
}
- // Print out the full Session tree from any subsession node
- public String printFullSessionTree() {
- // Get to the top of the tree
+ private Session getRootSession(String callingMethod) {
+ int currParentCount = 0;
Session topNode = this;
while (topNode.getParentSession() != null) {
+ if (currParentCount >= SESSION_RECURSION_LIMIT) {
+ Log.w(LOG_TAG, "getRootSession: Hit recursion limit from " + callingMethod);
+ break;
+ }
topNode = topNode.getParentSession();
+ currParentCount++;
}
- return topNode.printSessionTree();
+ return topNode;
+ }
+
+ // Print out the full Session tree from any subsession node
+ public String printFullSessionTree() {
+ return getRootSession("printFullSessionTree").printSessionTree();
}
// Recursively move down session tree using DFS, but print out each node when it is reached.
- public String printSessionTree() {
+ private String printSessionTree() {
StringBuilder sb = new StringBuilder();
- printSessionTree(0, sb);
+ printSessionTree(0, sb, 0);
return sb.toString();
}
- private void printSessionTree(int tabI, StringBuilder sb) {
+ private void printSessionTree(int tabI, StringBuilder sb, int currChildCount) {
+ // Prevent infinite recursion.
+ if (currChildCount >= SESSION_RECURSION_LIMIT) {
+ Log.w(LOG_TAG, "printSessionTree: Hit recursion limit!");
+ sb.append(TRUNCATE_STRING);
+ return;
+ }
sb.append(toString());
for (Session child : mChildSessions) {
sb.append("\n");
for (int i = 0; i <= tabI; i++) {
sb.append("\t");
}
- child.printSessionTree(tabI + 1, sb);
+ child.printSessionTree(tabI + 1, sb, currChildCount + 1);
}
}
@@ -279,11 +308,17 @@
// recent) will be truncated to "..."
public String getFullMethodPath(boolean truncatePath) {
StringBuilder sb = new StringBuilder();
- getFullMethodPath(sb, truncatePath);
+ getFullMethodPath(sb, truncatePath, 0);
return sb.toString();
}
- private synchronized void getFullMethodPath(StringBuilder sb, boolean truncatePath) {
+ private synchronized void getFullMethodPath(StringBuilder sb, boolean truncatePath,
+ int parentCount) {
+ if (parentCount >= SESSION_RECURSION_LIMIT) {
+ Log.w(LOG_TAG, "getFullMethodPath: Hit recursion limit!");
+ sb.append(TRUNCATE_STRING);
+ return;
+ }
// Return cached value for method path. When returning the truncated path, recalculate the
// full path without using the cached value.
if (!TextUtils.isEmpty(mFullMethodPathCache) && !truncatePath) {
@@ -296,7 +331,7 @@
// Check to see if the session has been renamed yet. If it has not, then the session
// has not been continued.
isSessionStarted = !mShortMethodName.equals(parentSession.mShortMethodName);
- parentSession.getFullMethodPath(sb, truncatePath);
+ parentSession.getFullMethodPath(sb, truncatePath, parentCount + 1);
sb.append(SUBSESSION_SEPARATION_CHAR);
}
// Encapsulate the external session's method name so it is obvious what part of the session
@@ -319,13 +354,10 @@
mFullMethodPathCache = sb.toString();
}
}
+
// Recursively move to the top of the tree to see if the parent session is external.
private boolean isSessionExternal() {
- if (getParentSession() == null) {
- return isExternal();
- } else {
- return getParentSession().isSessionExternal();
- }
+ return getRootSession("isSessionExternal").isExternal();
}
@Override
