From 03f8d1b6f7d35ffd68f21cf4358c3e029d86c01d Mon Sep 17 00:00:00 2001
From: Fred Gylys-Colwell <fredgc@google.com>
Date: Fri, 19 Nov 2021 22:48:54 +0000
Subject: [PATCH] Guard against double initialize

Merge from Widevine repo of http://go/wvgerrit/139498

If L1 OEMCrypto fails to initialize, we won't try again.

Bug: 206670307
Change-Id: I89084476ae01d9c98291392c2ce703ebc6326322
---
 .../core/src/oemcrypto_adapter_dynamic.cpp    | 43 +++++++++++++++----
 1 file changed, 34 insertions(+), 9 deletions(-)

diff --git a/libwvdrmengine/cdm/core/src/oemcrypto_adapter_dynamic.cpp b/libwvdrmengine/cdm/core/src/oemcrypto_adapter_dynamic.cpp
index 51bdfcb6..d0d2b3c6 100644
--- a/libwvdrmengine/cdm/core/src/oemcrypto_adapter_dynamic.cpp
+++ b/libwvdrmengine/cdm/core/src/oemcrypto_adapter_dynamic.cpp
@@ -718,7 +718,7 @@ struct LevelSession {
     level1_.Name = (L1_##Name##_t)dlsym(level1_library_, QUOTE(Function)); \
     if (!level1_.Name) {                                                   \
       LOGW("Could not load L1 %s. Falling back to L3.", QUOTE(Function));  \
-      if (level1_.Terminate) level1_.Terminate();                          \
+      if (level1_.Terminate) Level1Terminate();                            \
       return false;                                                        \
     }                                                                      \
   }
@@ -740,7 +740,11 @@ class Adapter {
  public:
   using map_iterator = std::map<OEMCrypto_SESSION, LevelSession>::iterator;
 
-  Adapter() : level1_valid_(false), level1_library_(nullptr) {}
+  Adapter()
+      : level1_valid_(false),
+        level1_initialized_(false),
+        level1_failed_(false),
+        level1_library_(nullptr) {}
 
   // The adapter is only destroyed on certain errors, or when the process
   // dies.  It is NOT deleted after each OEMCrypto_Terminate.
@@ -819,9 +823,23 @@ class Adapter {
     return result;
   }
 
+  OEMCryptoResult Level1Terminate() {
+    OEMCryptoResult result = OEMCrypto_SUCCESS;
+    if (level1_.Terminate && level1_initialized_) {
+      LOGE("L1 Terminate");
+      result = level1_.Terminate();
+    } else {
+      LOGE("L1 Terminate not needed");
+    }
+    level1_initialized_ = false;
+    return result;
+  }
+
   void FallBackToLevel3() {
+    Level1Terminate();
     level1_ = FunctionPointers();  // revert to all null pointers.
     level1_valid_ = false;
+    level1_failed_ = true;
     // Note: if the function pointers are bad, we do not close the library and
     // try again later.  Instead, we permanently fall back to L3.  This is a
     // debatable choice: I decided the risk of a dlclose resource leak out
@@ -833,6 +851,12 @@ class Adapter {
     if (metrics == nullptr) {
       return false;
     }
+    if (level1_failed_) {
+      // If we failed to initialize the level 1 library before, then we don't
+      // try again.
+      LOGE("Still falling back to L3.");
+      return false;
+    }
     level1_valid_ = true;
     const uint32_t kMinimumVersion = 8;
     const uint32_t kMaximumVersion = 16;
@@ -864,6 +888,7 @@ class Adapter {
               OEMCrypto_INITIALIZED_USING_L3_COULD_NOT_INITIALIZE_L1);
       return false;
     }
+    level1_initialized_ = true;
     level1_.version = level1_.APIVersion();
     level1_.security_level = wvcdm::kSecurityLevelUninitialized;
     metrics->SetL1ApiVersion(level1_.version);
@@ -874,7 +899,7 @@ class Adapter {
            level1_.version, kMinimumVersion);
       metrics->OemCryptoDynamicAdapterMetrics::SetInitializationMode(
           wvcdm::metrics::OEMCrypto_INITIALIZED_USING_L3_WRONG_L1_VERSION);
-      level1_.Terminate();
+      Level1Terminate();
       return false;
     }
 
@@ -996,7 +1021,6 @@ class Adapter {
         level1_.security_level = wvcdm::kSecurityLevelUnknown;
       }
     }
-
     return true;
   }
 
@@ -1083,7 +1107,7 @@ class Adapter {
     session_map_.clear();
     OEMCryptoResult result = Level3_Terminate();
     if (level1_valid_) {
-      result = level1_.Terminate();
+      result = Level1Terminate();
     }
     return result;
   }
@@ -1154,8 +1178,7 @@ class Adapter {
     if (!level1_.IsKeyboxOrOEMCertValid) {
       // TODO(b/189989043): add metrics.
       LOGE("L1 invalid function pointers. Falling back to L3");
-      if (level1_.Terminate) level1_.Terminate();
-      level1_valid_ = false;
+      FallBackToLevel3();
       return level3_.IsKeyboxOrOEMCertValid ? level3_.IsKeyboxOrOEMCertValid()
                                             : OEMCrypto_ERROR_NOT_IMPLEMENTED;
     }
@@ -1205,14 +1228,16 @@ class Adapter {
           wvcdm::metrics::
               OEMCrypto_INITIALIZED_USING_L3_COULD_NOT_INSTALL_KEYBOX);
     }
-    if (level1_.Terminate) level1_.Terminate();
-    level1_valid_ = false;
+    FallBackToLevel3();
     return level3_.IsKeyboxOrOEMCertValid ? level3_.IsKeyboxOrOEMCertValid()
                                           : OEMCrypto_ERROR_NOT_IMPLEMENTED;
   }
 
  private:
   bool level1_valid_;
+  bool level1_initialized_;
+  // If the level 1 fails to initialize once, we don't try again.
+  bool level1_failed_;
   void* level1_library_;
   struct FunctionPointers level1_;
   struct FunctionPointers level3_;