Dmod_SyncCode: make a loaded module's code safe to execute

inc/dmod_sal.h

@@ -99,6 +99,21 @@ DMOD_BUILTIN_API(Dmod, 1.0, bool,   _RetagEx,           ( void* Ptr, const char*
 DMOD_BUILTIN_API(Dmod, 1.0, bool,   _RenameTag,         ( const char* OldTag, const char* NewTag ) );
 DMOD_BUILTIN_API(Dmod, 1.0, size_t, _ReadMemory,        ( uintptr_t Address, void* Buffer, size_t Size ) );
 DMOD_BUILTIN_API(Dmod, 1.0, size_t, _WriteMemory,       ( uintptr_t Address, const void* Buffer, size_t Size ) );
+
+/**
+ * @brief Make code just written to memory safe to execute
+ *
+ * Called by the module loader once a module is loaded and relocated: on a
+ * core with caches, the code may still sit in the data cache, and the
+ * instruction cache may hold what was at these addresses before (a module
+ * unloaded from there). The system cleans the data cache for the range and
+ * invalidates the instruction cache. The default weak implementation does
+ * nothing - right for cores without caches and for hosts.
+ *
+ * @param Address Start of the code
+ * @param Size    Its size in bytes
+ */
+DMOD_BUILTIN_API(Dmod, 1.0, void,   _SyncCode,          ( const void* Address, size_t Size ) );
 //! @}
 
 /**

src/system/if/dmod_if_rawmem.c

@@ -182,6 +182,13 @@ DMOD_INPUT_WEAK_API_DECLARATION(Dmod, 1.0, size_t, _ReadMemory, ( uintptr_t Addr
  * 
  * @return Number of bytes successfully written
  */
+DMOD_INPUT_WEAK_API_DECLARATION(Dmod, 1.0, void, _SyncCode, ( const void* Address, size_t Size ))
+{
+    /* No caches to keep coherent - see dmod_sal.h */
+    (void)Address;
+    (void)Size;
+}
+
 DMOD_INPUT_WEAK_API_DECLARATION(Dmod, 1.0, size_t, _WriteMemory, ( uintptr_t Address, const void* Buffer, size_t Size ))
 {
     if (Buffer == NULL || Size == 0) 

src/system/private/dmod_ldr.c

@@ -607,11 +607,19 @@ bool Dmod_Ldr_Load( Dmod_Context_t* Context )
         return false;
     }
 
-    return Dmod_Ldr_LoadHeader( Context ) 
-        && Dmod_Ldr_LoadFooter( Context )
-        && Dmod_Ldr_LoadOutput( Context )
-        && Dmod_Ldr_LoadInput( Context )
-        && Dmod_Ldr_LoadGot( Context )
-        && Dmod_Ldr_LoadBss( Context )
-        && Dmod_RMod_ReadRequiredModules( Context );
+    if( !Dmod_Ldr_LoadHeader( Context )
+     || !Dmod_Ldr_LoadFooter( Context )
+     || !Dmod_Ldr_LoadOutput( Context )
+     || !Dmod_Ldr_LoadInput( Context )
+     || !Dmod_Ldr_LoadGot( Context )
+     || !Dmod_Ldr_LoadBss( Context ) )
+    {
+        return false;
+    }
+
+    /* The module is in place and relocated: what was written must reach
+     * the instruction fetch before any of it runs */
+    Dmod_SyncCode( Context->Data, Context->Size );
+
+    return Dmod_RMod_ReadRequiredModules( Context );
 }