Actually working(yes.) function loading and calling

Author: GAMINGNOOBdev

source/includes/fdlfcn.h

@@ -12,15 +12,18 @@ typedef struct
     Elf64_Rela* relocations;
 
     int symtab_index;
+    int text_section_index;
     void* string_table_data;
     void* text_section_data;
     void* data_section_data;
     void* rodata_section_data;
     void* symtab_str_section_data;
 
     Elf64_Shdr* text_section_header;
+    Elf64_Shdr* string_table_header;
     Elf64_Shdr* data_section_header;
     Elf64_Shdr* rodata_section_header;
+    Elf64_Shdr* symtab_str_section_header;
 } fdlfcn_handle;
 
 // immediately load sections into memory

source/kernel/C/fdlfcn.c

@@ -92,12 +92,14 @@ void* fdlsym(fdlfcn_handle* handle, const char* symbol_name)
 
     for (int j = 0; j < symtab_section.sh_size / sizeof(Elf64_Sym); j++)
     {
-        char* symbol_name_str = (char*)((uint64_t)handle->symtab_str_section_data + symbols[j].st_name); 
-        if (strcmp(symbol_name_str, symbol_name) == 0 && ELF64_ST_BIND(symbols[j].st_info) != STB_LOCAL)
+        Elf64_Sym symbol = symbols[j];
+        char* symbol_name_str = (char*)((uint64_t)handle->symtab_str_section_data + symbol.st_name); 
+        printf("Symbol name: '%s'", symbol_name_str);
+        if (strcmp(symbol_name_str, symbol_name) == 0 && ELF64_ST_BIND(symbol.st_info) != STB_LOCAL && symbol.st_shndx == handle->text_section_index)
         {
-            uintptr_t symbol_address = (uintptr_t)handle->text_section_data + symbols[j].st_value;
-            printf("Found symbol '%s'", symbol_name);
-            return (void*)symbol_address;
+            uintptr_t symbol_address = (uintptr_t)handle->text_section_data + symbol.st_value - handle->text_section_header->sh_offset;
+            if (symbol.st_shndx != SHN_UNDEF)
+                return (void*)symbol_address;
         }
     }
 
@@ -172,6 +174,7 @@ fdlfcn_handle* fdlopen(void* filedata, int flags)
     int data_section_index = -1;
     int rodata_section_index = -1;
     int reloc_section_index = -1;
+    int symtab_str_section_index = -1;
 
     void* strtableAddr = fdl_load_section(filedata, &section_headers[strtab_index]);
     for (int i = 0; i < elf_header.e_shnum; i++)
@@ -239,7 +242,9 @@ fdlfcn_handle* fdlopen(void* filedata, int flags)
         Elf64_Shdr symtab_section = section_headers[symtab_index];
         handle->symbols = malloc(symtab_section.sh_size);
         READ_FROM_MEMORY(handle->symbols, filedata, symtab_section.sh_offset, symtab_section.sh_size);
-        symtab_str_section_data = fdl_load_section(filedata, &section_headers[symtab_section.sh_link]);
+        symtab_str_section_index = symtab_section.sh_link;
+        if (symtab_str_section_index != -1)
+            symtab_str_section_data = fdl_load_section(filedata, &section_headers[symtab_str_section_index]);
     }
     else
         handle->symbols = NULL; 
@@ -255,12 +260,16 @@ fdlfcn_handle* fdlopen(void* filedata, int flags)
 
     handle->address = text_section_data;
     handle->text_section_data = text_section_data;
-    handle->symtab_str_section_data = symtab_str_section_data;
+    handle->text_section_index = text_section_index;
     handle->text_section_header = &section_headers[text_section_index];
+    handle->string_table_data = strtableAddr;
+    handle->string_table_header = &section_headers[strtab_index];
     handle->data_section_data = data_section_data;
     handle->data_section_header = &section_headers[data_section_index];
     handle->rodata_section_data = rodata_section_data;
     handle->rodata_section_header = &section_headers[rodata_section_index];
+    handle->symtab_str_section_data = symtab_str_section_data;
+    handle->symtab_str_section_header = &section_headers[symtab_str_section_index];
     handle->string_table_data = strtableAddr;
     handle->ehdr = elf_header;
     handle->shdrs = section_headers;

source/kernel/C/kernel.c

@@ -384,9 +384,14 @@ void main(void) {
     void* file_addr = module_request.response->modules[0]->address;
     elf_load_from_memory(file_addr);
     fdlfcn_handle* handle = fdlopen(file_addr, FDL_IMMEDIATE);
-    void* startFunction = fdlsym(handle, "frostedwm_create_context");
-    if (startFunction != NULL)
+    int(*startfunction)(void);
+    startfunction = (int(*)(void))fdlsym(handle, "_start");
+    if (startfunction != NULL)
+    {
+        int result = startfunction();
+        printf("Result function: %d\n", result);
         info("Successfully loaded function from .so file", __FILE__);
+    }
     fdlclose(handle);
 
     int failed_attempts = 0;