Pull cache flush out of Haystack am: 84d7185e5f am: 6304a242ae

am: 4354c9182a

Change-Id: I826e93e08dc046b52aea97a3619e73dae98fb2db

libwvdrmengine/cdm/core/src/oemcrypto_adapter_dynamic.cpp

@@ -13,6 +13,13 @@
 #include <stdio.h>
 #include <stdlib.h>
 #include <string.h>
+#include <sys/mman.h>
+#include <unistd.h>
+
+#if __mips__
+#include <sys/syscall.h>
+#include <asm/cachectl.h>
+#endif
 
 #include <iostream>
 #include <map>
@@ -235,6 +242,61 @@ struct FunctionPointers {
   L1_LoadKeys_V9_or_V10_t LoadKeys_V9_or_V10;
 };
 
+// The Cache Flush function is very processor dependent, but is needed by the
+// haystack code.  The haystack code is delivered as a static prebuilt library.
+// For that reason, we pass a function pointer for cache_flush into the
+// haystack.  The function is combiled outside of the haystack and may use
+// target (processor) specific compiler flags.
+void clear_cache_function(void *page, size_t len) {
+
+  // Note on cross platform support.  If __has_builtin is not defined as a
+  // preprocessor function, we cannot use
+  // "#if defined(__has_builtin) && __has_builtin(..)".
+  // So, instead, we will define USED_BUILTIN_CLEAR_CACHE if both conditions
+  // are true, and use "#ifndef  USED_BUILTIN_CLEAR_CACHE" instead of #else.
+#ifdef __has_builtin
+#if __has_builtin(__builtin___clear_cache)
+#pragma message "clear_cache_function is using __builtin___clear_cache."
+#define USED_BUILTIN_CLEAR_CACHE
+  char *begin = static_cast<char *>(page);
+  char *end = begin + len;
+  __builtin___clear_cache(begin, end);
+#endif
+#endif
+#ifndef USED_BUILTIN_CLEAR_CACHE
+#if __arm__
+#pragma message "clear_cache_function is using arm asm."
+  // ARM Cache Flush System Call:
+  char *begin = static_cast<char *>(page);
+  char *end = begin + len;
+  const int syscall = 0xf0002;
+  __asm __volatile (
+      "push      {r0, r1, r2, r7}\n"
+      "mov       r0, %0\n"
+      "mov       r1, %1\n"
+      "mov       r7, %2\n"
+      "mov       r2, #0x0\n"
+      "svc       0x00000000\n"
+      "pop       {r0, r1, r2, r7}\n"
+      :
+      : "r" (begin), "r" (end), "r" (syscall)
+      : "r0", "r1", "r7"
+                    );
+#elif __mips__
+#pragma message "clear_cache_function is using mips asm."
+  int result = syscall(__NR_cacheflush, page, len, ICACHE);
+  if (result) {
+    fprintf(stderr, "cacheflush failed!: errno=%d %s\n", errno,
+            strerror(errno));
+    exit(-1);  // TODO(fredgc): figure out more graceful error handling.
+  }
+#else
+#pragma message "clear_cache_function is not doing anything."
+  // TODO(fredgc): silence warning about unused variables.
+#endif
+#endif
+}
+
 struct LevelSession {
   FunctionPointers* fcn;
   OEMCrypto_SESSION session;
@@ -269,7 +331,7 @@ class Adapter {
 
   OEMCryptoResult Initialize() {
     LoadLevel3();
-    OEMCryptoResult result = Level3_Initialize();
+    OEMCryptoResult result = Level3_Initialize(clear_cache_function);
     if (force_level3()) {
       LOGW("Test code. User requested falling back to L3");
       return result;
@@ -416,7 +478,6 @@ class Adapter {
   }
 
   void LoadLevel3() {
-    level3_.Initialize = Level3_Initialize;
     level3_.Terminate = Level3_Terminate;
     level3_.OpenSession = Level3_OpenSession;
     level3_.CloseSession = Level3_CloseSession;

libwvdrmengine/oemcrypto/include/level3.h

@@ -64,7 +64,7 @@ namespace wvoec3 {
 extern "C" {
 
 bool Level3_PreInitialize(const char* path);
-OEMCryptoResult Level3_Initialize(void);
+OEMCryptoResult Level3_Initialize(void (*ClearCache)(void *, size_t));
 OEMCryptoResult Level3_Terminate(void);
 OEMCryptoResult Level3_OpenSession(OEMCrypto_SESSION *session);
 OEMCryptoResult Level3_CloseSession(OEMCrypto_SESSION session);
@@ -80,7 +80,6 @@ OEMCryptoResult Level3_GenerateSignature(OEMCrypto_SESSION session,
                                          size_t message_length,
                                          uint8_t* signature,
                                          size_t* signature_length);
-
 OEMCryptoResult Level3_LoadKeys(OEMCrypto_SESSION session,
                                 const uint8_t* message,
                                 size_t message_length,