Add support SHN_COMMON relocations (not tested)

loader/src/common/retain_vars.cpp

@@ -12,3 +12,7 @@ int ntfs_mount_count __attribute__((section(".data"))) = 0;
 
 struct buffer_store drc_store __attribute__((section(".data")));
 struct buffer_store tv_store __attribute__((section(".data")));
+
+
+char gbl_common_data[0x20000] __attribute__((section(".data")));
+char * gbl_common_data_ptr __attribute__((section(".data"))) = gbl_common_data;

loader/src/plugin/ElfTools.cpp

@@ -268,9 +268,22 @@ bool ElfTools::elfLink(Elf *elf, size_t shndx, void *destination, Elf32_Sym *sym
                     break;
                 }
                 case SHN_COMMON: {
-                    DEBUG_FUNCTION_LINE("case SHN_COMMON\n");
+                    u32 align = symtab[symbol].st_value;
+                    u32 size = symtab[symbol].st_size;
+
+                    uint32_t address = pluginData->getMemoryForCommonBySymbol(symbol, align, size);
+                    if(address == NULL){
+                        DEBUG_FUNCTION_LINE("Failed to get memory for common relocation\n");
                         return false;
                     }
+
+                    if (!ElfTools::elfLinkOne(ELF32_R_TYPE(rela[i].r_info), rela[i].r_offset,rela[i].r_addend, destination, address)) {
+                        DEBUG_FUNCTION_LINE("elfLinkOne failed\n");
+                        return false;
+                    }
+
+                    break;
+                }
                 case SHN_UNDEF: {
                     if (allow_globals) {
                         char *name = elf_strptr(elf, symtab_strndx, symtab[symbol].st_name);

loader/src/plugin/PluginData.cpp

@@ -0,0 +1,43 @@
+/****************************************************************************
+ * Copyright (C) 2018 Maschell
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ ****************************************************************************/
+
+#include <string>
+#include <vector>
+#include <map>
+#include "PluginData.h"
+#include "PluginLoader.h"
+
+ImportRPLInformation * PluginData::getImportRPLInformationBySectionHeaderIndex(int section_header_index) {
+    for(size_t i = 0; i< importRPLInformation_list.size(); i++) {
+        if(importRPLInformation_list[i] != NULL && importRPLInformation_list[i]->getSectionHeaderIndex() == section_header_index) {
+            return importRPLInformation_list[i];
+        }
+    }
+    return NULL;
+}
+
+uint32_t PluginData::getMemoryForCommonBySymbol(size_t symbol, size_t align, size_t size) {
+    std::map<size_t,uint32_t>::iterator it = memoryBySymbol.find(symbol);
+    if(it == memoryBySymbol.end()) {
+        memoryBySymbol[symbol] = PluginLoader::getInstance()->getMemoryFromDataSection(align, size);
+        DEBUG_FUNCTION_LINE("Setting value %08X\n",memoryBySymbol.find(symbol)->second);
+    } else {
+        DEBUG_FUNCTION_LINE("Using cached value %08X\n",memoryBySymbol.find(symbol)->second);
+    }
+
+    return memoryBySymbol.find(symbol)->second;
+}

loader/src/plugin/PluginData.h

@@ -20,6 +20,7 @@
 
 #include <string>
 #include <vector>
+#include <map>
 #include "FunctionData.h"
 #include "HookData.h"
 #include "PluginInformation.h"
@@ -108,19 +109,15 @@ public:
 
         \return A pointer to the corresponding ImportRPLInformation, return NULL if no corresponding information was found.
     **/
-   ImportRPLInformation * getImportRPLInformationBySectionHeaderIndex(int section_header_index) {
-        for(size_t i = 0; i< importRPLInformation_list.size(); i++) {
-            if(importRPLInformation_list[i] != NULL && importRPLInformation_list[i]->getSectionHeaderIndex() == section_header_index) {
-                return importRPLInformation_list[i];
-            }
-        }
-        return NULL;
-    }
+    ImportRPLInformation * getImportRPLInformationBySectionHeaderIndex(int section_header_index);
+
 
     PluginInformation * getPluginInformation() {
         return pluginInformation;
     }
 
+    uint32_t getMemoryForCommonBySymbol(size_t symbol, size_t align, size_t size);
+
 private:
 
     PluginInformation * pluginInformation;
@@ -129,6 +126,8 @@ private:
     std::vector<HookData *> hook_data_list;
     std::vector<RelocationData *> relocation_data_list;
     std::vector<ImportRPLInformation *> importRPLInformation_list;
+
+    std::map<size_t, uint32_t> memoryBySymbol;
 };
 
 

loader/src/plugin/PluginLoader.cpp

@@ -489,3 +489,18 @@ void PluginLoader::copyPluginDataIntoGlobalStruct(std::vector<PluginData *> plug
     DCFlushRange((void*)&gbl_replacement_data,sizeof(gbl_replacement_data));
     ICInvalidateRange((void*)&gbl_replacement_data,sizeof(gbl_replacement_data));
 }
+
+uint32_t PluginLoader::getMemoryFromDataSection(size_t align, size_t size) {
+    uint32_t ptr = (u32)gbl_common_data_ptr;
+    ptr = (ptr + (align - 1)) & -align;  // Round up to align boundary
+    uint32_t result = ptr;
+
+    if((result + size) >= (ptr + sizeof(gbl_common_data))) {
+        DEBUG_FUNCTION_LINE("No more space =( %08X > %08X\n",(result + size),(ptr + sizeof(gbl_common_data)));
+        return 0;
+    }
+    ptr += size;
+    gbl_common_data_ptr = (char *) ptr;
+
+    return result;
+}

loader/src/plugin/PluginLoader.h

@@ -27,8 +27,8 @@
 #define _PLUGIN_LOADER_H_
 
 #include <vector>
-#include "PluginInformation.h"
 #include "PluginData.h"
+#include "PluginInformation.h"
 #include "dynamic_libs/os_types.h"
 #include "dynamic_libs/os_functions.h"
 
@@ -42,6 +42,8 @@ extern "C" {
 }
 #endif
 
+extern char gbl_common_data[0x20000];
+extern char * gbl_common_data_ptr;
 
 #define PLUGIN_LOCATION_END_ADDRESS 0x01000000
 
@@ -123,6 +125,8 @@ public:
         this->currentStoreAddress = endAddress;
     }
 
+    uint32_t getMemoryFromDataSection(size_t align, size_t size);
+
 private:
     PluginLoader(void * startAddress, void * endAddress) {
         // TODO: Check if endAddress > startAddress.